chunk_uid
stringlengths
40
40
chunk_type
stringclasses
2 values
chunk_index
int64
0
6.71k
total_chunks
int64
1
6.71k
section_title
stringlengths
1
157
embed_text
stringlengths
1
83.3k
spans
dict
paper_doi
stringlengths
0
63
paper_id_arxiv
stringlengths
9
16
title
stringlengths
7
245
authors
listlengths
1
768
categories
listlengths
1
7
year
int64
2k
2.02k
language
stringclasses
2 values
discipline
stringclasses
8 values
dense_vector
listlengths
1.02k
1.02k
160025244eb6ca66e9066ee22b67c7093c110d6b
subsection
114
144
Rescaling classes
Since the image of _{[\Delta ]}^f is contained in F^\textup {found}, the rescaling class of [\Delta ] comes from a class of an F^\textup {found}-matroid [\Delta ^{\prime }] that is represented by a Grassmann-Plücker function \Delta ^{\prime }:\binom{E}{r}\rightarrow F^\textup {found}.Thus \Delta and \circ \Delta ^{\pri...
{ "cite_spans": [] }
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.03314916789531708, -0.026113362982869148, -0.017413996160030365, -0.043283168226480484, -0.011728883720934391, -0.0068068732507526875, 0.018665485084056854, 0.03934555873274803, 0.012285948731005192, 0.06168919801712036, -0.03372912481427193, -0.011446535587310791, -0.003743017092347145, ...
c4bb2cb403a40caa63953495eabcff5f3d3cbf6c
subsection
115
144
Foundations of binary matroids
A binary matroid is a matroid that is representableSince fields are perfect pastures, cf. Remark REF , it does not matter here if we talk about weak or strong representability. over the finite field {\mathbb {F}}_2 with two elements. In this section, we classify the foundations of binary matroids, and draw conclusions ...
{ "cite_spans": [] }
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.02631552889943123, -0.008443851955235004, -0.03282957524061203, -0.016521574929356575, -0.015346911735832691, -0.0455220527946949, 0.03999960422515869, -0.0007689664489589632, 0.0222118329256773, 0.038077425211668015, -0.07609383016824722, 0.020671037957072258, 0.011670364998281002, 0.0...
aeffa4d4b0a9a7f851bb2dfd878ac21189e354f7
subsection
116
144
Foundations of binary matroids
An example of such a matroid is the Fano plane, which is not representable over any field of characteristic different from 2, cf. .In fact, it is a classical result that a binary matroid fails to be regular only if it contains the Fano plane as a minor, cf. . Thus binary matroids are either representable over every fie...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.2307/2371182", "end": 131, "openalex_id": "https://openalex.org/W4255288880", "raw": "Hassler Whitney. On the abstract properties of linear dependence. Amer. J. Math., 57(3):509–533, 1935.", "source_ref_id": "9ab898dbc1369be50ee7a6...
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.020212478935718536, -0.017649689689278603, -0.0221345704048872, -0.03334677591919899, -0.00998420175164938, -0.03554345294833183, 0.03307219222187996, -0.0000066739316935127135, -0.01301988773047924, 0.02956361137330532, -0.0379536971449852, 0.007848544046282768, 0.0017609645146876574, ...
a882e9a8c6905a2ecac981c6d100929af68b6d8e
subsection
117
144
Foundations of binary matroids
Thus M is binary by Theorem REF .Conversely, let M be a binary matroid that is represented by a Grassmann-Plücker function \Delta :\binom{E}{r}\rightarrow {\mathbb {F}}_2, i.e. \Delta (I)=1 if I is a basis of M and \Delta (I)=0 otherwise. A 3-term Plücker relation is satisfied over {\mathbb {F}}_2 if and only if an eve...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.2307/2371182", "end": 1505, "openalex_id": "https://openalex.org/W4255288880", "raw": "Hassler Whitney. On the abstract properties of linear dependence. Amer. J. Math., 57(3):509–533, 1935.", "source_ref_id": "9ab898dbc1369be50ee7a...
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.03977134823799133, -0.018557926639914513, -0.04364775866270065, -0.04203004390001297, -0.01884789578616619, -0.004158745985478163, 0.026448098942637444, 0.004738681484013796, 0.016268709674477577, 0.025059306994080544, -0.06397601217031479, 0.018908940255641937, -0.0025830010417848825, ...
5886683ab29ec029f24b62ff87cd56c764db72a4
subsection
118
144
Foundations of binary matroids
By Corollary REF , the classes in {\mathcal {X}}^f_M(F) correspond bijectively to the morphisms k_M^f\rightarrow F. For both possibilities of k_M^f, there is at most one such morphism. Thus the theorem.
{ "cite_spans": [] }
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.029963279142975807, 0.007261976134032011, 0.0024390933103859425, -0.05083383247256279, -0.018765190616250038, -0.006933966651558876, -0.01920762099325657, 0.030771860852837563, 0.018139682710170746, -0.00717806676402688, -0.0218622088432312, -0.0010412392439320683, 0.0018278897041454911, ...
661d70d35c45956faf415d23db02831ce54ab01d
subsection
119
144
Foundations of regular matroids
Our results on binary matroids lead to a short proof of Tutte's characterization of regular matroids. While Tutte's original proof was based on his homotopy theory for matroids, cf. and , shorter and more elementary proofs were found later on, cf. and .Our proof has some ingredients in common with these latter approach...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1090/s0002-9947-1958-0101526-0", "end": 255, "openalex_id": "https://openalex.org/W2070056858", "raw": "William T. Tutte. A homotopy theorem for matroids, I. Trans. Amer. Math. Soc., 88:144–160, 1958.", "source_ref_id": "605ff1c0a7...
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.01753394864499569, -0.003906606696546078, -0.018968405202031136, -0.01406225748360157, 0.004887073300778866, -0.04401036351919174, -0.003551807254552841, 0.04889362305402756, 0.019426211714744568, 0.045505862683057785, -0.060399800539016724, -0.0017015102785080671, -0.0029852730222046375,...
f4a9db3e9ac420c9290ffb38b85dd12dec93bdca
subsection
120
144
Foundations of regular matroids
A regular matroid is binary and thus has precisely one rescaling class over every pasture by Corollary REF .Conversely, assume that M is a matroid that has exactly one rescaling class over every pasture. Then M is, in particular, representable over every pasture. Thus M is regular by Theorem REF .Corollary 3.37 Let M b...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1090/s0002-9947-1958-0101526-0", "end": 847, "openalex_id": "https://openalex.org/W2070056858", "raw": "William T. Tutte. A homotopy theorem for matroids, I. Trans. Amer. Math. Soc., 88:144–160, 1958.", "source_ref_id": "605ff1c0a7...
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.013031256385147572, -0.008995229378342628, -0.01623566448688507, -0.012710816226899624, 0.01132986880838871, -0.05926627665758133, -0.002967891516163945, 0.030716532841324806, 0.014740274287760258, 0.04040605202317238, -0.06421022117137909, -0.011177278123795986, 0.008041536435484886, 0...
34f9369f452a1e1c104d66db4a26013faeac6189
subsection
121
144
Foundations of regular matroids
Since both {\mathbb {S}} and {\mathbb {F}}_q (for q odd) are pastures with 1\ne , we reobtain the following well-known consequences of Tutte's characterization of regular matroids (cf. 7.52 in ) as immediate consequences of Theorem REF .Corollary 3.34 A matroid is regular if and only if it is binary and orientable.Cor...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.6028/jres.069b.001", "end": 237, "openalex_id": "https://openalex.org/W2324166574", "raw": "William T. Tutte. Lectures on matroids. J. Res. Nat. Bur. Standards Sect. B, 69B:1–47, 1965.", "source_ref_id": "896a7cc789c33b8b959fe84f2c...
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.03316240757703781, -0.0033978503197431564, -0.004595296923071146, -0.04118606448173523, -0.001232721726410091, -0.03615221008658409, 0.009838893078267574, 0.0330708846449852, -0.0003503675397951156, 0.04875209555029869, -0.04692160338163376, -0.006765192374587059, -0.003298698691651225, ...
10833174e68078d8924ad5b276fc8e1ef38b3dab
subsection
122
144
Uniqueness for rescaling classes over
A matroid is called ternary if it is representable over the field {\mathbb {F}}_3 with 3 elements. Brylawski and Lucas show in that every ternary matroid has a unique rescaling class over {\mathbb {F}}_3. We find the following short proof of this result, employing the foundation of a matroid.Theorem 3.38 Every matroid...
{ "cite_spans": [ { "arxiv_id": "", "doi": "", "end": 205, "openalex_id": "", "raw": "Tom Brylawski and Dean Lucas. Uniquely representable combinatorial geometries. In Proceedings of the International Colloquium on Combinatorial Theory. Rome, 1973.", "source_ref_id": "842089438...
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.027824535965919495, -0.00518562039360404, -0.020711954683065414, -0.02883189730346203, 0.008333624340593815, -0.026969805359840393, 0.035105008631944656, -0.0036459604743868113, -0.01353832334280014, 0.058549050241708755, -0.021200373768806458, -0.0013393324334174395, -0.00669666193425655...
830d538e37dae8e137a43cd281d1af500ea0b0eb
subsection
123
144
Uniqueness for rescaling classes over
Since f maps nonzero elements of k_M^f to {\mathbb {F}}_3^\times , we encounter the following possibilities. If a=0, then f(a)=0. If b=0, then a=^{i+1} and f(a)=(-1)^{i+1} is determined by i. If both a and b are nonzero, then f(a) and f(b) are units in {\mathbb {F}}_3 and f(a)+f(b)+(-1)^i=0. This is only possible if f(...
{ "cite_spans": [] }
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ 0.0022092340514063835, 0.017887545749545097, -0.017063375562429428, -0.026800792664289474, 0.0052006663754582405, -0.026693956926465034, 0.04508516192436218, 0.004490964114665985, 0.014201672747731209, 0.028647543862462044, -0.028418608009815216, -0.020482154563069344, 0.01898643933236599, ...
6600c95b0f863072e2f3c4263096e4323364ef1e
subsection
124
144
The bracket ring and the universal partial field
In , Pendavingh and Van Zwam introduce new techniques for establishing representability theorems for matroids. Their central tools are the bracket ring and the universal partial field. We will explain in this section how these two objects relate to the weak universal pasture and the foundation.In , Pendavingh and Van Z...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1016/j.jctb.2010.04.002", "end": 110, "openalex_id": "https://openalex.org/W2010114044", "raw": "Rudi A. Pendavingh and Stefan H. M. van Zwam. Confinement of matroid representations to subsets of partial fields. J. Combin. Theory Ser. B,...
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.019505731761455536, 0.018483130261301994, -0.02815968357026577, 0.014957446604967117, -0.013003821484744549, -0.08388380706310272, 0.04987850785255432, 0.0025965669192373753, 0.006814796011894941, 0.047955404967069626, -0.027564438059926033, 0.0018114917911589146, 0.02231406792998314, 0...
c3cc8edb15bcca0b16efb29718ed4912c0fdccad
subsection
125
144
The bracket ring
Pendavingh and van Zwam's bracket ring is a variation of White's bracket ring from . We recall the definition from .Definition 3.40 Let M be a matroid with representing Grassmann-Plücker function \Delta :\binom{E}{r}\rightarrow {\mathbb {K}}. Let\textstyle {\mathcal {B}}\ = \ \big \lbrace \, I\in \binom{E}{r} \, \big |...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1090/s0002-9947-1975-0387095-9", "end": 84, "openalex_id": "https://openalex.org/W2076545664", "raw": "Neil L. White. The bracket ring of a combinatorial geometry. I. Trans. Amer. Math. Soc., 202:79–95, 1975.", "source_ref_id": "6a...
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.04454831779003143, -0.0075938100926578045, -0.05113903060555458, -0.037377871572971344, -0.005438861437141895, -0.03399097919464111, 0.03399097919464111, 0.01411205343902111, 0.005076525267213583, 0.031046517193317413, -0.0734742134809494, 0.03466225415468216, 0.005202389322221279, -0.0...
91542bf8b3272e6ee4b0a8d8646fc138fc937cde
subsection
126
144
The bracket ring
Analogously, we define the partial degree-0 bracket field of M as P_{M,0}=(B_{M,0}^\times ,_{P_{M,0}}) where _{P_{M,0}}:{\mathbb {Z}}[B_{M,0}^\times ]\rightarrow B_{M,0} is the restriction of _{P_M} to the degree-0 elements.Pendavingh and van Zwam's bracket ring is a variation of White's bracket ring from . We recall t...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1090/s0002-9947-1975-0387095-9", "end": 308, "openalex_id": "https://openalex.org/W2076545664", "raw": "Neil L. White. The bracket ring of a combinatorial geometry. I. Trans. Amer. Math. Soc., 202:79–95, 1975.", "source_ref_id": "6...
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.02986672893166542, -0.004074816592037678, -0.04361732676625252, -0.02756224386394024, -0.0071194833144545555, -0.034735143184661865, 0.021427126601338387, 0.02399105578660965, 0.010545686818659306, 0.04093130677938461, -0.07148480415344238, 0.01157583761960268, 0.021015066653490067, -0....
81b19abbfcfa11bfc38c4dd6d23a72264142ad4f
subsection
127
144
The bracket ring
Analogously, we define the partial degree-0 bracket field of M as P_{M,0}=(B_{M,0}^\times ,_{P_{M,0}}) where _{P_{M,0}}:{\mathbb {Z}}[B_{M,0}^\times ]\rightarrow B_{M,0} is the restriction of _{P_M} to the degree-0 elements.
{ "cite_spans": [] }
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.036318838596343994, -0.013856095261871815, -0.011673913337290287, -0.025468967854976654, -0.0031626385170966387, -0.06989087909460068, 0.031084654852747917, 0.032320715487003326, 0.020326342433691025, 0.030855754390358925, -0.04062216356396675, -0.011521312408149242, 0.011292412877082825,...
8415fa3408c2517be28f63a6ac83842837369d0e
subsection
128
144
Relation to the weak universal pasture
We briefly recall from section that there are two ways to realize a partial field as an ordered blueprint. These two embeddings reflect the difference between the weak universal pasture and the partial bracket field, or between the foundation and the universal partial field, and provide a suitable language to compare t...
{ "cite_spans": [] }
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.04902483895421028, 0.028129756450653076, -0.021246131509542465, 0.013217780739068985, -0.03159446269273758, -0.05900685861706734, 0.0453617125749588, 0.0006534482818096876, 0.02950342930853367, 0.06422681361436844, -0.035043906420469284, -0.021932968869805336, 0.025061888620257378, 0.02...
2564b7e16d456d89f958bead2a0a0321c0ce930d
subsection
129
144
Relation to the weak universal pasture
Remark REF .Lemma 3.41 Let M be a matroid whose set of bases is {\mathcal {B}}. Let k_M^w be its weak universal pasture and P_{M,0} its partial degree-0 bracket field. Then k_M^w\otimes _{{\mathbb {F}}_1^\pm }{{\mathbb {F}}_{1^2}}\simeq P_{M,0}^\textup {blpr} and there are natural bijections{\mathcal {X}}_M(P^\textup ...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1016/j.aim.2018.12.004", "end": 1580, "openalex_id": "https://openalex.org/W2962744969", "raw": "Matthew Baker and Nathan Bowler. Matroids over partial hyperstructures. Preprint, arXiv:1709.09707, 2017.", "source_ref_id": "c29f3f46...
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.03319520130753517, 0.018443474546074867, -0.03115101344883442, -0.03890062868595123, -0.023462418466806412, -0.07182123512029648, 0.02253185398876667, -0.009366661310195923, 0.02721518464386463, 0.05061658099293709, -0.059739161282777786, -0.02852712757885456, -0.01456866692751646, 0.00...
f57aed0d3b4aa08c30042ba97190be701e256474
subsection
130
144
Relation to the weak universal pasture
The last bijection follows from the isomorphism k_M^w\otimes _{{\mathbb {F}}_1^\pm }{{\mathbb {F}}_{1^2}}\simeq P_{M,0}^\textup {blpr} and the fact that (-)^\textup {oblpr}:\operatorname{{PartFields}}\rightarrow \operatorname{{OBlpr}}^\pm is fully faithful.As a consequence of Lemma REF , we can reprove Theorem 4.6 from...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1016/j.jctb.2010.04.002", "end": 357, "openalex_id": "https://openalex.org/W2010114044", "raw": "Rudi A. Pendavingh and Stefan H. M. van Zwam. Confinement of matroid representations to subsets of partial fields. J. Combin. Theory Ser. B,...
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.016215138137340546, 0.0027724378742277622, -0.009983827359974384, -0.03114893101155758, -0.03346755728125572, -0.05277928337454796, 0.044114939868450165, -0.00003736069629667327, 0.01864054426550865, 0.022774413228034973, -0.01641344279050827, -0.016825303435325623, 0.03941666707396507, ...
14535b175b81ac12f5406f4c1ff48e8576e2f869
subsection
131
144
Relation to the weak universal pasture
By Corollary REF , such matroids are characterized by the property that their bracket ring is trivial. Since such matroids exist, for instance the Vámos matroid, this means that there are matroids M with trivial bracket ring B_M.On the other hand, the (weak) universal pasture is always nontrivial. This shows, in partic...
{ "cite_spans": [] }
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.04054976999759674, 0.016811830922961235, -0.033562637865543365, 0.0033829614985734224, -0.030984416604042053, -0.08274716138839722, 0.041465114802122116, 0.05086265131831169, 0.016445692628622055, 0.06712527573108673, -0.051259301602840424, -0.025324536487460136, 0.02910795994102955, 0....
4d657301aea584e0b2a900e2a960ad5a76f5f84c
subsection
132
144
Relation to the weak universal pasture
Note that we can recover the ambient ring of P as R_P=(P^\textup {oblpr}\otimes _{{\mathbb {F}}_1^\pm }{{\mathbb {F}}_{1^2}})^+=(P^\textup {blpr})^+; recall from section the notation B^+ for the ambient semiring of an ordered blueprint B.Recall from section REF the definition of the weak universal pasture k_M^w of M as...
{ "cite_spans": [] }
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.0425226166844368, 0.03879845142364502, -0.017582932487130165, -0.02019290067255497, -0.026984918862581253, -0.05564876273274422, 0.036325853317976, 0.007513193413615227, -0.005616770591586828, 0.05586244538426399, -0.04322471097111702, -0.00016646168660372496, 0.0032128538005053997, 0.0...
f733a41ed722dd6058aed4582803bcc7c22e030f
subsection
133
144
Relation to the weak universal pasture
The underlying monoids of both k_M^w\otimes _{{\mathbb {F}}_1^\pm }{{\mathbb {F}}_{1^2}} and P_{M,0}^\textup {blpr} are generated by the terms \pm x_J^{\pm 1}. Thus k_M^w\otimes _{{\mathbb {F}}_1^\pm }{{\mathbb {F}}_{1^2}}\simeq P_{M,0}^\textup {blpr}.We turn to the proof of the second claim. A partial field is a doubl...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1016/j.aim.2018.12.004", "end": 375, "openalex_id": "https://openalex.org/W2962744969", "raw": "Matthew Baker and Nathan Bowler. Matroids over partial hyperstructures. Preprint, arXiv:1709.09707, 2017.", "source_ref_id": "c29f3f46a...
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.018382729962468147, -0.002776478650048375, -0.024851009249687195, -0.03185322880744934, -0.026498589664697647, -0.06022822856903076, 0.03456868603825569, 0.00712426146492362, 0.02025914192199707, 0.022577958181500435, -0.050617340952157974, -0.025430714711546898, 0.019023455679416656, 0...
257654c661d392061fbc40a9aed7025a378b7554
subsection
134
144
Relation to the weak universal pasture
Thus {\mathcal {X}}_M(P^\textup {oblpr}) is nonempty and M is representable over the partial field P_M.The following fact shows that the class of representable matroids does not change if we ask for representability over fields or partial fields. This was already observed in . Note that for a partial field, strong and ...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1016/j.jctb.2009.03.006", "end": 277, "openalex_id": "https://openalex.org/W3100204681", "raw": "Rudi A. Pendavingh and Stefan H. M. van Zwam. Lifts of matroid representations over partial fields. J. Combin. Theory Ser. B, 100(1):36–67, ...
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.026850562542676926, 0.007212274707853794, -0.022975537925958633, -0.011098740622401237, -0.025599569082260132, -0.10093370079994202, 0.04476110637187958, 0.034264978021383286, 0.0005949840415269136, 0.04823947697877884, -0.02544700913131237, -0.00993928499519825, 0.03353269025683403, 0....
a9ff8a87f822fd338dc6eb0799388293b065ef4f
subsection
135
144
The universal partial field
The universal partial field of a matroid M was introduced by Pendavingh and van Zwam in as a device for proving representability theorems for matroids over partial fields. The definition in is somewhat technical, which is perhaps an inevitable consequence of their approach to matroid representations over partial fields...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1016/j.jctb.2010.04.002", "end": 172, "openalex_id": "https://openalex.org/W2010114044", "raw": "Rudi A. Pendavingh and Stefan H. M. van Zwam. Confinement of matroid representations to subsets of partial fields. J. Combin. Theory Ser. B,...
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.04534004256129265, -0.0018974319100379944, -0.03591199591755867, -0.04289912432432175, -0.01064850203692913, -0.012425795197486877, 0.03228113427758217, 0.009450927376747131, 0.04186173528432846, 0.03243368864059448, -0.06541658937931061, 0.002471428830176592, 0.040580250322818756, 0.03...
045ea039d8221a8531ad0fc2421ef495c0711428
subsection
136
144
The universal partial field
The second bijection comes from applying -\otimes _{{\mathbb {F}}_1^\pm }{{\mathbb {F}}_{1^2}} and (-)^{\textup {ppos}} to the morphism sets, cf. the proof of Lemma REF . The third bijection follows from k_M^f\otimes _{{\mathbb {F}}_1^\pm }{{\mathbb {F}}_{1^2}}\simeq {\mathbb {P}}_{M}^\textup {blpr} and the fact that (...
{ "cite_spans": [] }
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.04185914248228073, 0.008214704692363739, -0.023416103795170784, -0.01588023640215397, -0.0012337311636656523, -0.05162220820784569, 0.025734830647706985, 0.022195719182491302, 0.011189389042556286, 0.03639793023467064, -0.02716878056526184, -0.024544958025217056, 0.003985313698649406, 0...
99860ae2ad6b65137ddaa0901d5a64213a78a2f5
subsection
137
144
The universal partial field
Using the isomorphisms k_M^w\otimes _{{\mathbb {F}}_1^\pm }{{\mathbb {F}}_{1^2}}\rightarrow P_{M,0}^\textup {blpr} from Lemma REF and k_M^f\otimes _{{\mathbb {F}}_1^\pm }{{\mathbb {F}}_{1^2}}\rightarrow {\mathbb {P}}_M^\textup {blpr} from Lemma REF , we obtain a sequence of isomorphismsP_{M,0}^\textup {blpr}\ \simeq \ ...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1016/j.jctb.2010.04.002", "end": 1027, "openalex_id": "https://openalex.org/W2010114044", "raw": "Rudi A. Pendavingh and Stefan H. M. van Zwam. Confinement of matroid representations to subsets of partial fields. J. Combin. Theory Ser. B...
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.03687012568116188, 0.01845032349228859, -0.05420641228556633, -0.034581005573272705, -0.010987785644829273, -0.018206151202321053, 0.02481408417224884, -0.00940066110342741, 0.046301309019327164, 0.028354592621326447, -0.04431740194559097, 0.0020678401924669743, 0.020235838368535042, 0....
3a2f022526a3fe35efc7007817e4aef64abc2945
subsection
138
144
The universal partial field
Thus all operations that generate the strong equivalence relation come from scaling columns of a (non-truncated and possibly non-normalized) matrix representation A of M. This corresponds to the torus action appearing in the definition of rescaling classes.Let A be a truncated and normalized matrix representation of M....
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1016/j.jctb.2010.04.002", "end": 1013, "openalex_id": "https://openalex.org/W2010114044", "raw": "Rudi A. Pendavingh and Stefan H. M. van Zwam. Confinement of matroid representations to subsets of partial fields. J. Combin. Theory Ser. B...
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.02614111825823784, -0.016145536676049232, -0.06098068132996559, 0.011094333603978157, -0.0006132785929366946, -0.0037979397457093, 0.02047949843108654, 0.05328942462801933, 0.03912774473428726, 0.03216898813843727, -0.051671817898750305, -0.001586131053045392, 0.027133045718073845, 0.01...
b7e51015c665682e05d320cb58249ed33d3e54a1
subsection
139
144
The universal partial field
Recall from Lemma REF that the canonical morphism k_M^w\rightarrow P_{M,0}^\textup {oblpr} induces an isomorphism k_M^w\otimes _{{\mathbb {F}}_1^\pm }{{\mathbb {F}}_{1^2}}\rightarrow P_{M,0}^\textup {blpr}. The following lemma recovers in a more concise form.Lemma 3.46 The isomorphism k_M^w\otimes _{{\mathbb {F}}_1^\p...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1016/j.jctb.2010.04.002", "end": 261, "openalex_id": "https://openalex.org/W2010114044", "raw": "Rudi A. Pendavingh and Stefan H. M. van Zwam. Confinement of matroid representations to subsets of partial fields. J. Combin. Theory Ser. B,...
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.046480871737003326, 0.01776222325861454, -0.01651093363761902, -0.050417859107255936, -0.028749166056513786, -0.029222214594483376, 0.0259108729660511, 0.007774787489324808, 0.023118358105421066, 0.03299134597182274, -0.05926845222711563, -0.03070240095257759, 0.001642319024540484, 0.00...
5b24cf9e972163112a5328e7eb56f23ef13ed0f0
subsection
140
144
The universal partial field
Then we define P[T_1^{\pm 1},\cdots ,T_s^{\pm 1}] as the partial field (P^\times \times \lbrace \prod T_i^{e_i}\rbrace _{e_i\in {\mathbb {Z}}}, \hat{}_P) where\textstyle \hat{}_P: \ {\mathbb {Z}}[P^\times ][T_1^{\pm 1},\cdots ,T_s^{\pm 1}] \ \longrightarrow \ R_P[T_1^{\pm 1},\cdots ,T_s^{\pm 1}]is the extension of _P t...
{ "cite_spans": [] }
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.025080351158976555, 0.02906208671629429, -0.01620154082775116, -0.011098513379693031, 0.00845927931368351, -0.029473990201950073, -0.0026068156585097313, 0.01714739389717579, 0.016979580745100975, 0.06093122065067291, -0.04231927916407585, -0.024363333359360695, -0.011731624603271484, 0...
eb9978b5e59a0d2d78b23cbd669d9bbfa216411e
subsection
141
144
The universal partial field
Using the isomorphisms k_M^w\otimes _{{\mathbb {F}}_1^\pm }{{\mathbb {F}}_{1^2}}\rightarrow P_{M,0}^\textup {blpr} from Lemma REF and k_M^f\otimes _{{\mathbb {F}}_1^\pm }{{\mathbb {F}}_{1^2}}\rightarrow {\mathbb {P}}_M^\textup {blpr} from Lemma REF , we obtain a sequence of isomorphismsP_{M,0}^\textup {blpr}\ \simeq \ ...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1016/j.jctb.2010.04.002", "end": 1027, "openalex_id": "https://openalex.org/W2010114044", "raw": "Rudi A. Pendavingh and Stefan H. M. van Zwam. Confinement of matroid representations to subsets of partial fields. J. Combin. Theory Ser. B...
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.03687012568116188, 0.01845032349228859, -0.05420641228556633, -0.034581005573272705, -0.010987785644829273, -0.018206151202321053, 0.02481408417224884, -0.00940066110342741, 0.046301309019327164, 0.028354592621326447, -0.04431740194559097, 0.0020678401924669743, 0.020235838368535042, 0....
14cf44e0f94fc144457edab032a8a62044afaed6
subsection
142
144
The universal partial field
Thus all operations that generate the strong equivalence relation come from scaling columns of a (non-truncated and possibly non-normalized) matrix representation A of M. This corresponds to the torus action appearing in the definition of rescaling classes.Let A be a truncated and normalized matrix representation of M....
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1016/j.jctb.2010.04.002", "end": 1013, "openalex_id": "https://openalex.org/W2010114044", "raw": "Rudi A. Pendavingh and Stefan H. M. van Zwam. Confinement of matroid representations to subsets of partial fields. J. Combin. Theory Ser. B...
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.027124103158712387, -0.00333902589045465, -0.04570518061518669, 0.026910526677966118, -0.008954920805990696, -0.004305836744606495, 0.01864209957420826, 0.05601783096790314, 0.023096676915884018, 0.028512343764305115, -0.03774186223745346, 0.0018640193156898022, 0.018703121691942215, 0....
317116924d811e7a053ff2af83d96b90da7431d1
subsection
143
144
The universal partial fields of binary and regular matroids
Our classification of binary and regular matroids in terms of their foundation, cf. section REF and REF , yields a classification of such matroids in terms of their universal partial fields.Corollary 3.50 A matroid is binary if and only if its universal partial field is {{\mathbb {F}}_1^\pm } or {\mathbb {F}}_2. A mat...
{ "cite_spans": [] }
1809.03542
The moduli space of matroids
[ "Matthew Baker", "Oliver Lorscheid" ]
[ "math.AG" ]
2,018
en
Mathematics
[ -0.023386066779494286, -0.007745776791125536, -0.029488107189536095, -0.020075710490345955, -0.002404585015028715, -0.03362223878502846, -0.00871066190302372, 0.02683371864259243, 0.036886829882860184, 0.03816825896501541, -0.05799988657236099, -0.0026944319251924753, 0.002906096400693059, ...
61f22206aa5e16b7e4e99d92d008fa1dff959eaa
abstract
0
29
Abstract
Over the past decade, Airbnb has emerged as the most popular platform for renting out single rooms or whole apartments. The impact of Airbnb listings on local neighborhoods has been controversially discussed in many cities around the world. The platform's widespread adoption led to changes in urban life, and in particu...
{ "cite_spans": [] }
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.06256478279829025, 0.0090795224532485, -0.017701255157589912, 0.00696605397388339, -0.015015547163784504, -0.0031721105333417654, 0.015221552923321724, 0.013489576987922192, 0.010605492629110813, 0.027696359902620316, 0.037050556391477585, 0.03894276171922684, -0.03476160019636154, -0.0...
5c28faa6d87e7a40b60c0c37b482160dc6d2b080
subsection
1
29
Introduction
Airbnb, the largest digital peer-to-peer distribution platform for accommodations, operates in about 81,000 cities in 191 countries, offering 4.5 million rooms, apartments, houses, and other types of accommodation . The widespread adoption of Airbnb led to changes in urban life and in particular urban tourism. Visitors...
{ "cite_spans": [ { "arxiv_id": "", "doi": "", "end": 215, "openalex_id": "https://openalex.org/W647377220", "raw": "Airbnb Inc. 2018. Fast Facts. (2018). https://press.atairbnb.com/fast-facts/", "source_ref_id": "6f68a9dc55f7df57907802d55783d2afac714f32", "start": 0 ...
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.04983445629477501, 0.0030936729162931442, -0.02575644850730896, 0.02117888070642948, -0.010642845183610916, 0.009040696546435356, -0.009750219993293285, -0.0005330959102138877, -0.013625893741846085, 0.010642845183610916, 0.036376405507326126, 0.05532753840088844, -0.03857363760471344, ...
8877d7d6e5a67f0030e8d54baf425e79fe3d32ca
subsection
2
29
Introduction
With regard to the CSCW community, he argues that the concept of place has been widely adapted to inform location-based technologies, whereas implications of a “discursive place shaping” on online platforms have not been considered yet. With our research, we try to fill this gap. The overarching goal of our research is...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1080/15022250216287", "end": 999, "openalex_id": "https://openalex.org/W2008548137", "raw": "Wolfgang Framke. 2002. The Destination as a Concept: A Discussion of the Business-related Perspective versus the Socio-cultural Approach in Tour...
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.07994141429662704, 0.010252028703689575, -0.022975528612732887, 0.00269459025003016, 0.02273143269121647, -0.03133581578731537, 0.00037734751822426915, -0.023601025342941284, -0.0032247360795736313, 0.03597363829612732, 0.0529077909886837, 0.026804784312844276, -0.034325990825891495, -0...
ae47633e374854fd0c587ebddc7a6c352b82c82f
subsection
3
29
Introduction
Moreover, we analyzed which practices are encouraged in the listings (see Sections REF , REF , REF ) and investigated how places named by Airbnb hosts and visitBerlin, the city's destination management and marketing organization (DMO), differ (see Sections REF  and REF ).This paper provides a twofold contribution: From...
{ "cite_spans": [] }
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.06956842541694641, -0.019299136474728584, -0.00823836587369442, 0.005484615918248892, -0.02601187862455845, -0.0020061947870999575, 0.026423797011375427, 0.015042646788060665, 0.008589259348809719, 0.05150504410266876, 0.006472457200288773, 0.02010771632194519, -0.046500999480485916, -0...
fc91d236edff55705f72c648552aad74760f512b
subsection
4
29
Theoretical Background
Understanding space and place on a conceptual level is a central goal of geography. Much empirical work, however, deals with natural or cultural phenomena happening in distinct places. Considering the nature of space just became popular again after the “spatial turn”  in social sciences from the late 1960s onwards . Th...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.5860/choice.27-1646", "end": 317, "openalex_id": "https://openalex.org/W2034769775", "raw": "Edward W. Soja. 1989. Postmodern Geographies: The Reassertion of Space in Critical Social Theory. Verso, London, UK.", "source_ref_id": "c...
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.05317945405840874, 0.005388882011175156, -0.01441611722111702, -0.019007917493581772, -0.020548686385154724, -0.007864030078053474, -0.03481225296854973, -0.03067810647189617, 0.03584960103034973, 0.032127346843481064, 0.048267293721437454, 0.0426228903234005, -0.030998464673757553, -0....
a34b8a22ba69a3197a23525f30339053a0ecb1e7
subsection
5
29
Traditional Understandings of Urban Tourism Space
Traditionally, tourism space, in the sense of a tourist destination, has been defined as a geographical area , that contains agglomerations of tourism-related attractions, facilities, and services , . Accordingly, the destination is a stable and closed spatial unit, valorized for tourism purposes and filled up with tou...
{ "cite_spans": [ { "arxiv_id": "", "doi": "", "end": 201, "openalex_id": "https://openalex.org/W1591773406", "raw": "A. J. Burkart and S. Medlik. 1976. Tourism: Past, present and future (reprint ed.). Heinemann, London.", "source_ref_id": "688e2f0bb8b1369f3796cbc2ea4a08cf89dba...
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.036294277757406235, 0.026388902217149734, -0.02802199125289917, -0.0007273546070791781, 0.019429191946983337, -0.009004888124763966, -0.040140435099601746, 0.0326923243701458, 0.04874849691987038, 0.019139204174280167, 0.03189867362380028, 0.06776560097932816, -0.05140417441725731, -0.0...
417dfc7e8aed0c2e1522b5dccba5233ea6a1bbbd
subsection
6
29
Traditional Understandings of Urban Tourism Space
At the same time, increasing affluence, more leisure time, and the ubiquitous proliferation of the car and the rise of the airplane as a means of transportation  enabled people to travel not only to the countryside but also to urban destinations . After the fall of the Berlin Wall, Germany’s capital, which we focus on ...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1080/00420989220080581", "end": 247, "openalex_id": "https://openalex.org/W2764535316", "raw": "Christopher M. Law. 1992. Urban Tourism and its Contribution to Economic Regeneration. Urban Studies 29, 3/4 (1992), 599–618.", "source...
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.028630299493670464, 0.035375818610191345, -0.015055324882268906, 0.02534910850226879, -0.013842047192156315, -0.011705458164215088, -0.025745902210474014, 0.044929422438144684, -0.0012399849947541952, 0.0005498856189660728, 0.013948877342045307, 0.05832889303565025, -0.03507059067487717, ...
603b6bd71fdd089dcaa21c3b8456acb4a1c043fc
subsection
7
29
Constructing New Urban Tourism Space
Tourism in general and tourist behavior in particular have changed. Tourists are no longer staying within the confines of the central tourist zone with major sights in walking distance and gastronomic infrastructure just around the corner. Instead, many of them are now venturing into residential neighborhoods. Urban to...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1016/j.tourman.2009.07.009", "end": 413, "openalex_id": "https://openalex.org/W2013789783", "raw": "Robert Maitland and Peter Newman (Eds.). 2009. World tourism cities: Developing tourism off the beaten track. Routledge studies in contem...
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.03918416053056717, -0.002433751244097948, -0.00906362570822239, -0.011474489234387875, -0.012405265122652054, -0.026336394250392914, -0.01875285431742668, 0.016845526173710823, 0.02114845998585224, 0.019210614264011383, 0.02114845998585224, 0.026046479120850563, -0.02786225639283657, -0...
4728792ed0c8c337df8d9fa7b81e47b691a86af0
subsection
8
29
Constructing New Urban Tourism Space
Following Dourish’s point of view , we establish that such technologies influence the way people move through the city and encounter urban space. Moreover, information on online platforms is no longer solely provided by the city's DMO. Due to social web applications, many people can now produce content online, for exam...
{ "cite_spans": [ { "arxiv_id": "", "doi": "", "end": 145, "openalex_id": "", "raw": "Paul Dourish. 2006. Re-Space-ing Place: Place and Space Ten Years On. In 2006 ACM Conference on Computer Supported Cooperative Work (CSCW 2006), Pamela J. Hinds and David Martin (Eds.). ACM, Banff, ...
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.03972170129418373, -0.005945289507508278, -0.0355115681886673, 0.027121808379888535, -0.009930425323545933, -0.017587989568710327, -0.012729555368423462, 0.001527317799627781, 0.029806531965732574, 0.03496241942048073, 0.03252176195383072, 0.041491180658340454, -0.005106313619762659, -0...
d9ff1e8247dfdfafee18962aacd227618814cc99
subsection
9
29
Constructing New Urban Tourism Space
We argue that through the means of digital technologies, local people are now empowered to participate in the discourse producing and reproducing urban space. [Figure: Overview of our conceptual approach: Airbnb hosts perceive their city and neighborhood and capture this perception in their listing descriptions. Guests...
{ "cite_spans": [] }
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.05665929615497589, -0.001448328490369022, 0.0013443996431306005, -0.007810866925865412, 0.0003921165771316737, -0.04573628678917885, 0.02698715589940548, 0.005022906232625246, 0.027246499434113503, 0.02988571859896183, 0.02454626001417637, 0.032036758959293365, -0.03740672767162323, -0....
e2ebda746ce8eea79b869b233acfa32dd881252c
subsection
10
29
From Theoretical Concepts to Empirical Research
The city depiction in Figure REF represents the city in its multitude of dimensions. It stands for buildings and infrastructure, but likewise for people, for flows of information and capital, for images and feelings associated with it, for its various representations in pictures and discourses, and for everyday practic...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1016/s0160-7383(99)00030-4", "end": 894, "openalex_id": "https://openalex.org/W2060041453", "raw": "Seyhmus Baloglu and Ken W. McCleary. 1999. A model of destination image formation. Annals of Tourism Research 26, 4 (1999), 868–897.", ...
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.0371377095580101, -0.0007085383986122906, -0.031553320586681366, 0.004176848102360964, 0.007586986757814884, -0.0329570472240448, 0.02232229709625244, 0.007499254308640957, 0.006393056828528643, 0.012679308652877808, 0.014685721136629581, 0.05016795173287392, -0.043118804693222046, -0.0...
7d3a12adfd90116dbd5a9d25e4caf7b3c91ec4be
subsection
11
29
From Theoretical Concepts to Empirical Research
We have theoretically motivated the relation of those digital descriptions to the physical world, that is the neighborhood and the city, and peoples' performances in that environment. We consider it to be an important direction for future work to also analyze Airbnb from a user perspective. On the one hand, one could e...
{ "cite_spans": [] }
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.07470706850290298, 0.033447280526161194, -0.002084732986986637, -0.0014095313381403685, -0.0045166038908064365, -0.024398814886808395, 0.018386850133538246, -0.028854383155703545, 0.026535047218203545, 0.035064712166786194, -0.005836489610373974, 0.031112685799598694, -0.03591920807957649...
b126ba15270c6aecb146051a626a5c7376ad10e1
subsection
12
29
Research Design
As motivated above, our goal was to analyze and compare how the two neighborhoods Kreuzkölln and City West are constructed as tourism spaces in Airbnb listing descriptions (RQ1 and RQ2). For our analysis, we deliberately chose two very different neighborhoods. The neighborhood we denote City West has a long tradition o...
{ "cite_spans": [ { "arxiv_id": "", "doi": "", "end": 462, "openalex_id": "", "raw": "visitBerlin. 2018c. Kaiser-Wilhelm-Gedächtnis-Kirche: Mahnmal gegen Krieg und Zerstörung. (2018). https://www.visitberlin.de/de/kaiser-wilhelm-gedaechtnis-kirche", "source_ref_id": "2c6e17845c...
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.08483284711837769, 0.02152862399816513, -0.030149228870868683, 0.0008162872982211411, 0.0035817467141896486, 0.013068226166069508, 0.01260286569595337, -0.024732742458581924, -0.011336476542055607, 0.03616076335310936, 0.04018880054354668, 0.019941823557019234, -0.015868015587329865, 0....
37526259e2b9e4a4d94e7d6c462d3a02f028da54
subsection
13
29
Data Collection
To retrieve the Airbnb listings in the two neighborhoods, we utilized Tom Slee's airbnb-data-collection toolhttps://github.com/tomslee/airbnb-data-collection. On March 22, 2017, we collected all listings within two bounding boxes encompassing the Kreuzkölln and City West areas. Afterwards, we utilized the LOR shapefile...
{ "cite_spans": [ { "arxiv_id": "", "doi": "", "end": 423, "openalex_id": "", "raw": "Amt für Statistik Berlin-Brandenburg. 2016. RBS-LOR, Lebensweltlich orientierte Räume Dezember 2015. (2016). https://daten.berlin.de/datensaetze/rbs-lor-lebensweltlich-orientierte-r%C3%A4ume-dezembe...
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.07621660083532333, -0.0038920657243579626, -0.04573606327176094, 0.0050038122572004795, 0.00596872391179204, 0.0002191789826611057, 0.012242558412253857, -0.019511815160512924, -0.03484361991286278, 0.034691061824560165, 0.037070926278829575, 0.04561401903629303, -0.018504951149225235, ...
1ee5eec371e0b8a46723234883ebfe27aecfb515
subsection
14
29
Data Collection
The retrieval failed for three hosts. There is no universally accepted threshold for the number of listings that a host must provide to be considered professional. Nevertheless, we observed that most hosts (80%) in the two areas provide only one listing. However, there is a considerable difference between the two neigh...
{ "cite_spans": [ { "arxiv_id": "", "doi": "", "end": 839, "openalex_id": "", "raw": "visitBerlin. 2018e. Neukölln: Lively and bustling - and vibrantly diverse. (2018). https://www.visitberlin.de/en/districts/neukolln", "source_ref_id": "3cd6c7c8798176ff03ce81b3d0ee7a4ece6754b1...
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.07903987914323807, -0.01492297276854515, -0.022552303969860077, -0.013152968138456345, 0.013549692928791046, 0.01175680011510849, 0.03451509773731232, -0.015975819900631905, -0.01791367121040821, 0.04672202840447426, 0.04644737020134926, 0.011199858970940113, -0.007141054607927799, 0.01...
7c5723a0cdb2c6de18cbc9946d64f170a3d0b25f
subsection
15
29
Qualitative Data Analysis
Figure REF shows an exemplary Airbnb listing from the Kreuzkölln neighborhood and visualizes where the information we analyzed is located on the Airbnb website. The median length of the listing descriptions (including house rules) was 138.5 words for Kreuzkölln and 117.5 words for City West; the median title length was...
{ "cite_spans": [ { "arxiv_id": "", "doi": "", "end": 705, "openalex_id": "https://openalex.org/W1803273808", "raw": "Johnny Saldana. 2015. The coding manual for qualitative researchers. Sage, Thousand Oaks, CA, USA.", "source_ref_id": "0d49246457143bda85184f1409a02b161223e684"...
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.08060769736766815, -0.013470211066305637, -0.03749691694974899, -0.0037126983515918255, 0.008863185532391071, -0.006380425300449133, 0.03746640682220459, -0.027230268344283104, -0.027520114555954933, 0.055040229111909866, 0.015163521282374859, 0.041554760187864304, 0.004103608895093203, ...
4f56af36fb491cc089147a81625b66844d6e497a
subsection
16
29
Quantitative Data Analysis
After we finished our qualitative analysis of the listing descriptions, we used the resulting coding schema to compare those descriptions to the borough descriptions of visitBerlin (RQ3). We extracted the places from the borough descriptions on the DMO's website, as described in Section REF , and compared those places ...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.5281/zenodo.1407522", "end": 1893, "openalex_id": "https://openalex.org/W4393881803", "raw": "Natalie Stors and Sebastian Baltes. 2018. Constructing Urban Tourism Space Digitally — Supplementary Material. (2018). http://doi.org/10.5281/z...
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.06769867241382599, 0.018969668075442314, -0.025867730379104614, -0.016985712572932243, -0.000980531913228333, 0.00859205424785614, 0.0506671778857708, -0.015314611606299877, -0.0005374802858568728, 0.05494031310081482, 0.028278999030590057, 0.004181568045169115, -0.021441983059048653, 0...
1086d7e971a1689a4834e3bcd2d75d9f6b13851e
subsection
17
29
Results
In this section, we summarize key findings from our qualitative and quantitative data analyses. As described above, the four high-level concepts places, facilities, adjectives, and practices emerged from the qualitative data. Table REF shows the number of listings in which particular places in the neighborhood or other...
{ "cite_spans": [] }
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.06766767054796219, -0.01644403673708439, -0.04216263070702553, 0.011608452536165714, 0.005872870329767466, -0.028937233611941338, 0.006906342692673206, 0.026908423751592636, -0.027457574382424355, 0.03554230555891991, -0.007104647345840931, 0.007089393213391304, -0.05430498346686363, -0...
4a8016d35355e0e359b99819bfa8237995828950
subsection
18
29
Places and Facilities
To spatially reference the location of an Airbnb room or apartment in the city, it was common for hosts to name specific places in the neighborhood or in the city. This is particularly true for the short listing headlines, which we analyzed first. The most frequently mentioned places in those headlines were Berlin, Neu...
{ "cite_spans": [ { "arxiv_id": "", "doi": "", "end": 1897, "openalex_id": "", "raw": "Amt für Statistik Berlin-Brandenburg. 2017g. Regionaler Sozialbericht Berlin und Brandenburg 2017. Statistik Berlin-Brandenburg Regionaler Sozialbericht 2017 (2017), 1–110.", "source_ref_id":...
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.06816129386425018, 0.023951036855578423, -0.0231424979865551, 0.00014528421161230654, -0.01862688921391964, 0.008909175172448158, 0.03429422155022621, -0.024774830788373947, -0.026849569752812386, 0.01961849257349968, 0.031578756868839264, 0.039969246834516525, -0.025324026122689247, 0....
8cf85cb32d775e72a0c9e0d78f79374d254a92b3
subsection
19
29
Places and Facilities
In doing so, they contribute to the public discourse , , , , framing the neighborhood as a trendy and upcoming area, a so-called Szenekiez. The adjectives illustrated in Figure REF directly refer to the neighborhood's transformation (upcoming) and its new image (hip, cool, vibrant, and trendy).The district Charlottenbu...
{ "cite_spans": [ { "arxiv_id": "", "doi": "", "end": 139, "openalex_id": "", "raw": "Deutsche Presse Agentur. 2017. Neukölln: Zwischen Szenekiez und organisierter Kriminalität. (2017). http://www.zeit.de/news/2017-07/12/medien-neukoelln‐-zwischen-szenekiez-und-organisierter-kriminal...
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.032128553837537766, 0.03878004848957062, -0.025858450680971146, -0.0035069093573838472, 0.002318869810551405, -0.026926351711153984, 0.014142055064439774, -0.01589646376669407, 0.0040236967615783215, 0.038139306008815765, 0.04964212328195572, 0.03725447505712509, -0.05519520491361618, 0...
da8d0a2b441a59556e180d02972455f162e5298a
subsection
20
29
Streets and Squares
Large streets and squares structure the urban fabric  of a neighborhood. In our case study, for each neighborhood one important street emerged from the listing descriptions. Kurfürstendamm is the street that is mentioned most frequently (35) and it is primarily framed as Berlin’s famous shopping street: “Berlin’s main ...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.51347/jum.v3i2.3885", "end": 72, "openalex_id": "https://openalex.org/W4293392899", "raw": "Albert Levy. 1999. Urban morphology and the problem of the modern urban fabric: Some questions for research. Urban Morphology 3, 2 (1999), 79–85....
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.045950211584568024, 0.02427184022963047, -0.04707913100719452, 0.012738521210849285, 0.008634733967483044, 0.002648773370310664, 0.03420330956578255, -0.03667473420500755, -0.01826108992099762, 0.05418829619884491, 0.0540662482380867, 0.03688831627368927, -0.04418054595589638, 0.0046987...
2562304aa155be0891bbb47a85074c0d08eb4984
subsection
21
29
Sights, Parks, and Markets
Sights and other attractions, such as museums or art galleries, are often considered to be facilities that are primarily tourism-related and attract visitors. In Ashworth and Tunbridge’s tourist-historic city model , , they belong to the decisive elements that define urban tourism space. This section deals with sights ...
{ "cite_spans": [ { "arxiv_id": "", "doi": "", "end": 288, "openalex_id": "", "raw": "Gregory John Ashworth and J. E. Tunbridge. 1990. The touristic-historic city. Belhaven Press, London, UK and New York, NY, USA.", "source_ref_id": "54bc62f8239d157313cfc30d44a81e036ce25d83", ...
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.06531250476837158, 0.029878944158554077, -0.03360236808657646, 0.0060391174629330635, 0.01216979417949915, -0.0061192321591079235, 0.008454001508653164, -0.008629490621387959, -0.028017232194542885, 0.038058266043663025, 0.043826520442962646, -0.008782089687883854, -0.005741548724472523, ...
a0779145cf425a6f7561ef42c8658233aea2ecd4
subsection
22
29
Sights, Parks, and Markets
Instead of gazing upon Landwehrkanal, hosts encouraged other practices. They invited guests to “take a bike ride along the tree-lined Landwehr Canal” (4243519), to “stroll” along (6089778), to “hang out” (879602), or to “jog or take walks” (16462941). One host even related being at the canal to a common local practice:...
{ "cite_spans": [ { "arxiv_id": "", "doi": "", "end": 1940, "openalex_id": "", "raw": "visitBerlin. 2018g. Tiergarten: Die grüne Lunge Berlins. (2018). https://www.visitberlin.de/de/tiergarten", "source_ref_id": "942759483f53a8c587a36416c9f7f779d145abf8", "start": 1779 ...
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.062149252742528915, 0.022547028958797455, -0.04378211870789528, 0.006296540144830942, -0.0046451762318611145, 0.004240916110575199, 0.02721508778631687, -0.002112830523401499, -0.013447364792227745, 0.04539915919303894, 0.030830545350909233, -0.0010373464319854975, -0.032737430185079575, ...
4f8b4752a6583950b1320de308725fc31b8e0fa6
subsection
23
29
Sights, Parks, and Markets
This mix of people visiting it, and the offers that are still primarily dedicated to the local residents, mark it as an authentic place—a place that is not artificially designed to meet only visitors' needs. [Table: Places mentioned by visitBerlin, the city's DMO, in their borough descriptions of Neukölln and Charlotte...
{ "cite_spans": [] }
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.06104985997080803, 0.027029825374484062, -0.017231322824954987, 0.02675510197877884, -0.019932780414819717, -0.02483203075826168, 0.07148938626050949, -0.026404064148664474, 0.001978397136554122, 0.046306319534778595, 0.03882770985364914, 0.03446264564990997, -0.019871730357408524, 0.01...
0b11c8d418b5989221b3928641a94a26f94fc1f1
subsection
24
29
Comparison with DMO Website
After extracting the places mentioned in visitBerlin's description of the two boroughs in which the neighborhoods Kreuzkölln and City West are located (see Section REF ), we first compared those places with the places frequently mentioned by Airbnb hosts (gray background in Table REF ). Then, we conducted a follow-up q...
{ "cite_spans": [ { "arxiv_id": "", "doi": "", "end": 1649, "openalex_id": "", "raw": "visitBerlin. 2018e. Neukölln: Lively and bustling - and vibrantly diverse. (2018). https://www.visitberlin.de/en/districts/neukolln", "source_ref_id": "3cd6c7c8798176ff03ce81b3d0ee7a4ece6754b...
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.0499994233250618, 0.0041856965981423855, -0.04349766671657562, -0.0020394299644976854, -0.003226076951250434, 0.015857569873332977, 0.03137936815619469, -0.01956631802022457, -0.022511949762701988, 0.04505442455410957, 0.03708748146891594, -0.0007721789297647774, -0.03907158598303795, 0...
d2ef8ca904405da0c4ac01e96e0b61167a9e7cc6
subsection
25
29
Discussion
Questions regarding the conceptual nature of space and place have been addressed in both CSCW and human geography research. For CSCW scholars, the main motivation to use spatial metaphors has long been to transfer spatial structures from the physical world into the digital realm . Examples include the organization of t...
{ "cite_spans": [ { "arxiv_id": "", "doi": "", "end": 281, "openalex_id": "", "raw": "Steve Harrison and Paul Dourish. 1996. Re-Place-ing Space: The Roles of Place and Space in Collaborative Systems. In 1996 ACM Conference on Computer Supported Cooperative Work (CSCW 1996), Mark S. A...
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.0707254409790039, 0.022075001150369644, -0.014988727867603302, 0.012227445840835571, -0.0020156598184257746, 0.028436630964279175, -0.009489047341048717, -0.009961973875761032, 0.026666969060897827, 0.02262420766055584, 0.03444737568497658, 0.020091760903596878, -0.03536272048950195, -0...
211944b695d4423be98852619ed9a9687ab77afe
subsection
26
29
Discussion
Hosts encourage their guests to buy typical food in order to experience the neighborhoods' multicultural atmosphere. As a result of these neighborhood descriptions, certain space images are collaboratively constructed and (re-)produced by Airbnb hosts. In the case of Kreuzkölln, a residential area and its prevalent loc...
{ "cite_spans": [ { "arxiv_id": "", "doi": "", "end": 2742, "openalex_id": "", "raw": "DWIF Consulting. 2017. 12 mal Berliner Leben, 12 mal Berlin erleben: Konzept für einen stadtverträglichen und nachhaltigen Berlin-Tourismus 2018+. (2017).", "source_ref_id": "34fea3855053b40f...
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.06360874325037003, 0.017000993713736534, -0.03305579349398613, -0.0003068934893235564, -0.00682176323607564, 0.020831558853387833, 0.015734313055872917, 0.0023731188848614693, -0.012079251930117607, 0.029133658856153488, 0.016268454492092133, 0.0038610873743891716, -0.025989849120378494, ...
a8eb63220fe7b3c8a73b84d0cd0e2eee34cd3412
subsection
27
29
Discussion
We thus hypothesize that digital information sharing platforms are more important in the production of new urban tourism areas than the city's DMO.Our finding that, through digital representations of space in Airbnb listing descriptions, mundane places can gain significance for visitors and thus transform into tourist ...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1080/14616688.2016.1208677", "end": 517, "openalex_id": "https://openalex.org/W2489983413", "raw": "Jingfu Chen and Ningning Chen. 2016. Beyond the everyday? Rethinking place meanings in tourism. Tourism Geographies 19, 1 (2016), 9–26.",...
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.06294389069080353, -0.0038500477094203234, -0.026770995929837227, 0.013996010646224022, -0.023016341030597687, -0.007314709015190601, 0.036783408373594284, 0.017231730744242668, 0.005315279122442007, 0.042644333094358444, 0.024695251137018204, 0.013957854360342026, -0.009913205169141293, ...
b48e447d8d200b59f46a68e2b50cef0e0ea1b817
subsection
28
29
Conclusion and Future Work
In this paper, we illustrated how urban tourism space is (re-)produced digitally and collaboratively on online platforms. In particular, we investigated how Airbnb hosts construct their neighborhoods as touristic places in their listing descriptions. We followed a constructionist notion of space, building on existing r...
{ "cite_spans": [ { "arxiv_id": "", "doi": "", "end": 360, "openalex_id": "", "raw": "Edward W. Soja. 2009. Vom Zeitgeist zum Raumgeist: New Twists on the Spatial Turn. In Spatial Turn, Joerg Doering and Tristan Thielmann (Eds.). Transcript, Bielefeld, Germany, 241–262.", "sour...
10.1145/3274435
1809.03398
Constructing Urban Tourism Space Digitally: A Study of Airbnb Listings in Two Berlin Neighborhoods
[ "Natalie Stors", "Sebastian Baltes" ]
[ "cs.CY", "cs.HC" ]
2,018
en
Computer Science
[ -0.0736202746629715, -0.00795111246407032, -0.020312726497650146, 0.009332255460321903, -0.0007177557563409209, 0.007561950013041496, 0.026066217571496964, -0.0029435139149427414, -0.0008784757810644805, 0.039984479546546936, 0.013399378396570683, 0.027439730241894722, -0.01268209982663393, ...
f015f28a62d61a1bd3126b5df0ef8cfa4be7f9be
abstract
0
45
Abstract
We consider the control of a three-dimensional thin liquid film on a flat substrate, inclined at a non-zero angle to the horizontal. Controls are applied via same-fluid blowing and suction through the substrate surface. We consider both overlying and hanging films, where the liquid lies above or below the substrate, re...
{ "cite_spans": [] }
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.028790585696697235, -0.0010527559788897634, -0.020139679312705994, 0.008826366625726223, -0.011404856108129025, 0.04000472649931908, 0.019605671986937523, 0.020612655207514763, -0.01595916971564293, 0.04613817110657692, -0.020338023081421852, -0.010374985635280609, -0.006812398787587881, ...
88ed737c913fd1432e595209b9a27c2f23a067f3
subsection
1
45
Introduction
The dynamics of thin liquid films in various physical situations form a range of classical and important problems in fluid mechanics, attracting a lot of attention from researchers in the field (see , and the references therein). In this work, we study the optimal control problem for a gravity-driven, thin, viscous liq...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1007/978-1-84882-367-9", "end": 230, "openalex_id": "https://openalex.org/W1503652556", "raw": "Serafim Kalliadasis, Christian Ruyer-Quil, Benoit Scheid, and Manuel García Velarde. Falling liquid films, volume 176. Springer Science & Bus...
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.06113079562783241, 0.031343650072813034, -0.028078049421310425, 0.0017243585316464305, -0.00012112473632441834, 0.004913658834993839, -0.01284876000136137, 0.006016179919242859, -0.0005636592395603657, 0.05350089073181152, -0.02751343697309494, -0.008827799931168556, -0.002153540728613734...
989517d6df4e1eb90280f61987b9b4d8dbf76c28
subsection
2
45
Introduction
This partial differential equation (PDE) exhibits a range of dynamical behaviours in windows of the bifurcation parameter L, including steady and travelling waves, time-periodic and quasi-periodic solutions, and full spatiotemporal chaos , , . It has been observed that (REF ) possesses a finite-dimensional global attra...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1137/0150045", "end": 243, "openalex_id": "https://openalex.org/W2046527278", "raw": "I. G. Kevrekidis, B. Nicolaenko, and J. C. Scovel. Back in the saddle again: a computer assisted study of the Kuramoto–Sivashinsky equation. SIAM J. Ap...
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.041769351810216904, 0.032127924263477325, -0.040365852415561676, 0.0012242478551343083, -0.011716166511178017, -0.0021567356307059526, 0.02317298948764801, 0.009290553629398346, -0.0071662357077002525, 0.039908189326524734, -0.024729043245315552, -0.003091130405664444, -0.0060564037412405...
4cb5f1428bf74003f3f529df3231f7e53602f0ac
subsection
3
45
Introduction
In a related study, Lin and Kondic considered the case of a non-wetted substrate with numerical simulations of a Benney equation, and observed that fluid fronts were unstable to a transverse fingering instability. Thin rivulets form with approximately equal width in the spanwise direction, with fast moving “drop-like" ...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1063/1.3682001", "end": 214, "openalex_id": "https://openalex.org/W3104714283", "raw": "T-S Lin, L Kondic, and A Filippov. Thin films flowing down inverted substrates: Three-dimensional flow. Physics of Fluids, 24(2):022105, 2012.", ...
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.08183785527944565, 0.03716573491692543, -0.04879147186875343, 0.009192264638841152, 0.006610039155930281, 0.021237563341856003, -0.018765950575470924, 0.03255816176533699, -0.009215150028467178, 0.062309056520462036, -0.009939851239323616, -0.007323297671973705, -0.0018031713552772999, ...
6222261e7f82bbe6d384ef633c97fb53fe83d26d
subsection
4
45
Introduction
The current paper is organised as follows: In section , we present the physical problem, and discuss the hierarchy of models culminating with (REF ). In section , we consider purely transverse controls, \zeta = \tilde{\zeta }(y,t). Seeking an optimal control of this form reduces to a linear quadratic regulator (LQR) pr...
{ "cite_spans": [] }
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.05114426091313362, 0.009963365271687508, -0.02903565764427185, 0.01240461878478527, -0.03016473725438118, 0.03362826630473137, -0.02857792377471924, 0.024961816146969795, 0.04009758681058884, 0.06286227703094482, -0.020659107714891434, 0.00135699356906116, -0.0004934955504722893, 0.0170...
5b358f41eb5feed46f394c12561a5a2de221f9c0
subsection
5
45
Physical problem and governing equations
We consider a Newtonian fluid with constant density \rho , dynamic viscosity \mu , and kinematic viscosity \nu , flowing under gravity along a flat infinite 2D substrate inclined at a non-zero angle \theta to the horizontal – the schematic of the problem is presented in Figure REF . Same-fluid blowing and suction contr...
{ "cite_spans": [ { "arxiv_id": "", "doi": "", "end": 2391, "openalex_id": "", "raw": "W. Nusselt. Die oberflŠchenkondensation des wasserdampfe. Z. Ver. Deut. Indr., 60:541–546, 1916.", "source_ref_id": "263c9a572acf70a417451f3232baeca26b2f9be5", "start": 1811 }, ...
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.03900991380214691, 0.011896802112460136, -0.03363765403628349, -0.019886508584022522, 0.009554070420563221, 0.003409170312806964, 0.005902614910155535, 0.011744181625545025, 0.028601163998246193, 0.03635430708527565, -0.01712406985461712, -0.012095209211111069, 0.011354997754096985, -0....
106120208792f939eba29e27d58acf9470b60326
subsection
6
45
Physical problem and governing equations
The non-dimensional Navier–Stokes equations for this problem are{\operatorname{\mathit {R\hspace{-1.99997pt}e}}} \left( {u}_t + ({u} {\cdot } {\nabla } ){u} \right)= & - {\nabla } p + {\nabla }^2 {u} + 2 {\overline{g}} ,\\ {\nabla }{\cdot }{u} = & \; 0,where {u}= (u,v,w) is the velocity field, p is the pressure, {\nabl...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1017/jfm.2017.250", "end": 920, "openalex_id": "https://openalex.org/W2559481134", "raw": "R. J. Tomlin, D. T. Papageorgiou, and G. A. Pavliotis. Three-dimensional wave evolution on electrified falling films. Journal of Fluid Mechanics, ...
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ 0.011354440823197365, 0.011026321910321712, -0.032750844955444336, 0.003897366113960743, 0.018176261335611343, 0.052712686359882355, 0.03272032365202904, 0.011262873187661171, 0.01620754785835743, 0.02647843398153782, -0.006325827445834875, -0.0023025553673505783, 0.02617320604622364, -0.0...
bee46026b3cf25873cb93b360bab4419b26d71f0
subsection
7
45
Fully nonlinear Benney equation
In order to reduce the Navier–Stokes formulation to a forced evolution equation for the film thickness, we make a long-wave assumption. The details of the following derivation are omitted since they are similar to those in for the case of a fully 3D model of an electrified thin film, and the derivation for the 2D case ...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1017/jfm.2017.250", "end": 337, "openalex_id": "https://openalex.org/W2559481134", "raw": "R. J. Tomlin, D. T. Papageorgiou, and G. A. Pavliotis. Three-dimensional wave evolution on electrified falling films. Journal of Fluid Mechanics, ...
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.03806230425834656, 0.00472344970330596, -0.047066621482372284, 0.026066727936267853, -0.01379644125699997, 0.015620196238160133, -0.014345857314765453, 0.00876776035875082, 0.012087147682905197, 0.018573306500911713, -0.027867591008543968, -0.01311730220913887, 0.009851330891251564, 0.0...
5ec115a6a7e66ed2171e2a8afec2219cdc823b00
subsection
8
45
Fully nonlinear Benney equation
As observed by a number of authors , , , the uncontrolled 1D simplification (no spanwise variation) of this Benney equation exhibits finite-time blow-ups in numerical simulations. The existence of an optimal control for (REF ) is an open problem (lack of analytical results for the uncontrolled equation is problematic),...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1017/s0022112083002943", "end": 179, "openalex_id": "https://openalex.org/W2081519565", "raw": "A. Pumir, P. Manneville, and Y. Pomeau. On solitary waves running down an inclined plane. J. Fluid Mech., 135:27–50, 1983.", "source_re...
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.08375073224306107, 0.04239422827959061, -0.0034508262760937214, -0.04520219936966896, -0.024020344018936157, 0.03418397158384323, 0.029025854542851448, 0.0502077080309391, -0.008454428985714912, 0.024600250646471977, -0.03071979247033596, -0.015405678190290928, 0.009957607835531235, 0.0...
0019102381118a1e5893727c3b4254279d11e114
subsection
9
45
Weakly nonlinear evolution: 2D Kuramoto–Sivashinsky equation
We seek to analyse the evolution of a sufficiently small perturbation about the non-dimensional exact constant solution to (REF ) given by H=1, F=0. For this, we substitute H = 1 + \delta \eta and F = 4 \delta ^2 \zeta into equation (REF ) where \eta , \zeta are O(1) quantities, and also assume that \cot \theta is O(1)...
{ "cite_spans": [] }
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.02319197915494442, 0.006740169133991003, -0.023100432008504868, -0.006148926448076963, 0.007403886877000332, -0.02285630628466606, 0.009581949561834335, 0.007804406341165304, 0.03433023393154144, 0.0040738545358181, -0.04314928874373436, 0.006339649669826031, -0.0304547306150198, 0.0269...
1c61c9cbba42df9d995ca9991f2eb29708ab445f
subsection
10
45
Weakly nonlinear evolution: 2D Kuramoto–Sivashinsky equation
Note that the rescaling (REF ) involves a Galilean transformation, so (REF ) is in a moving reference frame. For our investigation of optimal controls with actuators at every point on the substrate, the advection term makes no difference and the result in the moving frame can be translated back into the “lab" frame wit...
{ "cite_spans": [] }
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.03099074587225914, 0.008308449760079384, -0.03274551406502724, 0.0038356962613761425, 0.02067575603723526, -0.0021267037373036146, 0.02027902565896511, 0.02059946209192276, 0.0265656765550375, 0.059479039162397385, -0.03463761508464813, -0.0010480929631739855, -0.004936241544783115, 0.0...
c91361e770e1d2337fc6bf869569f544a4324455
subsection
11
45
Weakly nonlinear evolution: 2D Kuramoto–Sivashinsky equation
The controls considered in this work can thus be thought of as moving fluid from one location to another, without changing the total fluid volume.From the ODE description (REF ), it can be observed that the dynamics of the transverse modes (i.e. k_1 = 0) are linear, being governed by\frac{\mathrm {d}}{\mathrm {d}t} \ti...
{ "cite_spans": [] }
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.06083124130964279, 0.03415462002158165, -0.038916122168302536, 0.015299377031624317, 0.0025505321100354195, -0.022052468731999397, -0.020297428593039513, 0.0789310485124588, -0.0031495350413024426, 0.024356914684176445, -0.04950741305947304, -0.02048056200146675, 0.0076191662810742855, ...
af6ad15b90b4f2d84dac1e3cc3e0eb2ca26f8bb5
subsection
12
45
Weakly nonlinear evolution: 2D Kuramoto–Sivashinsky equation
When \kappa = 0, the film is vertical, and the canonical equation (REF ) reduces to a forced version of the thin film equation obtained by Nepomnyashchy , ,\eta _t + \eta \eta _x + \eta _{xx} + \Delta ^2 \eta = \zeta .Without controls, this equation has been studied both analytically and numerically by a number of auth...
{ "cite_spans": [ { "arxiv_id": "", "doi": "", "end": 218, "openalex_id": "", "raw": "A. A. Nepomnyashchy. Periodical motion in tridimensional space of fluid films running down a vertical plane. Hydrodynamics, Perm State Pedagogical Institute, 7:43–54, 1974.", "source_ref_id": ...
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.037316955626010895, 0.026698559522628784, -0.012594091705977917, 0.027919063344597816, -0.010572629049420357, -0.0015199107583612204, 0.004489171784371138, 0.0064267246052622795, -0.0026679488364607096, 0.024059215560555458, -0.025630615651607513, 0.0048476955853402615, 0.0068615297786891...
4842062f6f6afe19281a3b0c2978ba2cbf78a294
subsection
13
45
Weakly nonlinear evolution: 2D Kuramoto–Sivashinsky equation
We denote the three components of the cost functional by \mathcal {C}_{s,\gamma }^{(1)}, \mathcal {C}_{s,\gamma }^{(2)}, and \mathcal {C}_{s,\gamma }^{(3)}, respectively. The optimal control \zeta ^* and associated optimal state \eta ^* (which solves the KSE (REF ) with \zeta = \zeta ^*) are defined as minimisers of th...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1098/rspa.2017.0687", "end": 2017, "openalex_id": "https://openalex.org/W2795314400", "raw": "R. J. Tomlin, A. Kalogirou, and D. T. Papageorgiou. Nonlinear dynamics of a dispersive anisotropic Kuramoto–Sivashinsky equation in two space d...
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.04166160523891449, 0.030673930421471596, -0.04224151372909546, -0.031147010624408722, 0.014985970221459866, 0.009377676993608475, 0.04425591975450516, 0.008324691094458103, 0.03519108518958092, 0.07270179688930511, -0.01719876565039158, 0.035038478672504425, 0.016283126547932625, 0.0122...
7a59983a8063dd6eabc1f0f76a53b3ef3303fac3
subsection
14
45
Weakly nonlinear evolution: 2D Kuramoto–Sivashinsky equation
These schemes were utilised for the corresponding 1D optimal control problem by Gomes et al. , and their applicability was checked for similar multi-dimensional problems in (including a convergence study) and for a non-local problem. In order to perform computations, we truncate the Fourier series (REF ) to |k_1| \le M...
{ "cite_spans": [ { "arxiv_id": "", "doi": "", "end": 235, "openalex_id": "", "raw": "S. N. Gomes, D. T. Papageorgiou, and G. A. Pavliotis. Stabilizing non-trivial solutions of the generalized Kuramoto–Sivashinsky equation using feedback and optimal control. IMA J. Appl. Math., pages...
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.024747366085648537, 0.03133852779865265, -0.030941836535930634, -0.050806861370801926, -0.02685287594795227, 0.02813449129462242, 0.0018375529907643795, -0.016249042004346848, 0.03561057522892952, 0.06066308915615082, -0.04360540956258774, 0.028714267536997795, 0.008788214065134525, 0.0...
c8505c064ce1d5ef8ea1e1118f2e33adb40763ed
subsection
15
45
Optimal transverse control for hanging films
We first consider controlling the transverse instabilities present for hanging films (\kappa < 0) by applying controls of the form \zeta = \tilde{\zeta }(y,t) (with \tilde{\zeta }_{0} = 0). We work under the assumption that the dynamics of (REF ) are bounded if the linear growth in the spanwise dimension is controlled....
{ "cite_spans": [] }
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.049677371978759766, 0.012205742299556732, -0.035457681864500046, 0.008223618380725384, 0.0022389907389879227, 0.000985041493549943, 0.00985613651573658, 0.05983864888548851, -0.007304373662918806, 0.04494764655828476, -0.040462035685777664, -0.026776347309350967, 0.019086729735136032, 0...
81866335c50289b77761a33de38982173e1376f8
subsection
16
45
Optimal transverse control for hanging films
The desired state is taken to be the orthogonal projection \overline{\eta } = (I -\tilde{P}_{\Xi }) \eta = \eta - \tilde{\eta }_{\textrm {u}}, with no components of unstable transverse modes. It is important to note that due to the slaving of the streamwise and mixed modes to the transverse modes, \overline{\eta } is n...
{ "cite_spans": [ { "arxiv_id": "", "doi": "", "end": 1291, "openalex_id": "https://openalex.org/W1499788862", "raw": "Jerzy Zabczyk. Mathematical control theory: an introduction. Springer Science & Business Media, 2009.", "source_ref_id": "a02ea3c7ae7e412e837af78ca55b9f2320a2e...
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.04067356884479523, 0.001093693426810205, -0.03521177917718887, 0.009077560156583786, 0.013349352404475212, 0.05092587321996689, 0.026210499927401543, 0.03582203388214111, 0.029368575662374496, 0.04549459367990494, -0.0201231949031353, -0.02492896281182766, -0.00708278501406312, 0.007197...
e4e6b1ec6cf7ea53537bcba18f9efc14e6b1d369
subsection
17
45
Optimal transverse control for hanging films
The optimal control (derived in appendix ) is given by \tilde{\zeta }_{k_2}^* = r_{k_2}\tilde{\eta }_{k_2}^* (with stars denoting optimality) where r_{k_2} satisfies a Riccati equation and final time boundary condition\frac{\mathrm {d}}{\mathrm {d}t}r_{k_2} = - r_{k_2}^2 + 2 (\kappa \tilde{k}_2^2 + \tilde{k}_2^4) r_{k_...
{ "cite_spans": [] }
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.03784480318427086, 0.03601360321044922, -0.02282896265387535, 0.004280430264770985, -0.03592204302549362, -0.00503961555659771, 0.026705002412199974, 0.03314472362399101, 0.037051282823085785, 0.05853736400604248, -0.028276782482862473, 0.013451691716909409, -0.003540320321917534, 0.037...
76ca3dda322bc9424467bc01c99711cf7884cf8a
subsection
18
45
Optimal transverse control for hanging films
Substituting back into (REF ) yields the solution\tilde{\eta }_{k_2}^* = \exp \left( - t \; \sqrt{ (\kappa \tilde{k}_2^2 + \tilde{k}_2^4)^2 + |\tilde{k}_2|^{2s}/\gamma } \right)\tilde{v}_{k_2},where the optimal control is defined by \tilde{\zeta }_{k_2}^* = \lambda _{-} \tilde{\eta }_{k_2}^*. [Figure: Application of op...
{ "cite_spans": [] }
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.07738018780946732, 0.033533450216054916, -0.03264858201146126, 0.009504703804850578, 0.001411212026141584, 0.04180239140987396, 0.01194571889936924, 0.06062871962785721, 0.024410154670476913, 0.0635274276137352, -0.03316729888319969, 0.03585241362452507, 0.005641034338623285, 0.02917013...
ed0348da4679ae920b1673c5a1603a56801eb48c
subsection
19
45
Optimal transverse control for hanging films
With the application of the optimal transverse controls, the H_0^2-norm of the unstable modes and the L_0^2-norm of the control decay exponentially as shown in Figure REF (c), and the energy of the full solution remains bounded as desired with a modal steady state (dominated by the (m,2m)-modes for m\in \mathbb {Z}) em...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1098/rspa.2017.0687", "end": 2822, "openalex_id": "https://openalex.org/W2795314400", "raw": "R. J. Tomlin, A. Kalogirou, and D. T. Papageorgiou. Nonlinear dynamics of a dispersive anisotropic Kuramoto–Sivashinsky equation in two space d...
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.059848714619874954, 0.010368995368480682, -0.057101957499980927, 0.01023165788501501, -0.0005631798994727433, 0.008789611980319023, -0.024232471361756325, 0.024583445861935616, 0.019074678421020508, 0.04526039958000183, -0.04382598400115967, -0.01532841194421053, 0.02989383600652218, 0....
00e62d8b54c3630497bdc21b5471d5340c725bee
subsection
20
45
Optimal transverse control for hanging films
With the length parameters L_1 = 40 and L_2 = 27, as in case (ii), we find mostly chaotic dynamics as \kappa is decreased to -0.44, below which a time-periodic attractor emerges. This behaviour dominates until \kappa = -0.58 when steady modal waves dominated by the (m,3m)-modes for m\in \mathbb {Z} appear – this is sim...
{ "cite_spans": [] }
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.06391274929046631, -0.007008579093962908, -0.03952579200267792, -0.008752139285206795, -0.008691095747053623, -0.002022072207182646, -0.025867264717817307, 0.054328884929418564, -0.022311469539999962, 0.030033497139811516, -0.031223848462104797, -0.010163774713873863, 0.019274545833468437...
cf83dab8865106bf1780ee6ba49323a88bc0ebc3
subsection
21
45
Full optimal control
In this section, we consider the general optimal control problem for the 2D KSE (REF ), where the set of admissible controls F_{\textrm {ad}} is a non-empty, closed, convex subset of L^2(0,T;L_0^2). We consider the existence of an optimiser for our problem, and then give the methodology for numerical simulations. In co...
{ "cite_spans": [ { "arxiv_id": "", "doi": "", "end": 871, "openalex_id": "https://openalex.org/W3091814460", "raw": "J.L. Lions. Quelques méthodes de résolution des problèmes aux limites non linéaires. Etudes mathématiques. Dunod, 1969.", "source_ref_id": "c6d6eed7a2bf97ea6b43...
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.045492008328437805, 0.019252486526966095, -0.0035945854615420103, 0.004328757990151644, -0.0015150653198361397, 0.03221968933939934, 0.0008018690859898925, 0.019969496876001358, 0.023356225341558456, 0.04598018527030945, -0.04732267186045647, 0.01475973054766655, -0.00012275938934180886, ...
cd48b1c39b1a851d34331b1bcda3e52ebb2b4354
subsection
22
45
Full optimal control
The optimal control problem can thus be recast as the problem of finding the minimiser of \tilde{\mathcal {C}}_{s,\gamma }(\zeta ) over F_{\textrm {ad}}. It makes sense to check that there exist \zeta \in F_{\textrm {ad}} which give a finite value of \tilde{\mathcal {C}}_{s,\gamma }. The boundedness of the first and la...
{ "cite_spans": [ { "arxiv_id": "", "doi": "", "end": 2087, "openalex_id": "", "raw": "F. Tröltzsch. Optimal Control of Partial Differential Equations: Theory, Methods, and Applications. American Mathematical Society, 2010.", "source_ref_id": "e88519cdcd233709b916172bbde0894349...
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.03512636199593544, 0.02037084847688675, -0.009063882753252983, -0.011223039589822292, -0.0005979645065963268, 0.011352742090821266, 0.01898227259516716, 0.010391421616077423, 0.015083583071827888, 0.0806899219751358, -0.0270390585064888, -0.00019371855887584388, -0.01620512455701828, 0....
835a2d2d578f725707bc41e0cc40e5fa78900fea
subsection
23
45
Full optimal control
Then, the sequence \lbrace \zeta ^{(n)}\rbrace _{n=1}^{\infty } \subseteq K has a weakly convergent subsequence \zeta ^{(n)} \rightharpoonup \zeta ^* for the topology of L^2(0,T;L_0^2) (not relabelled for simplicity) with weak limit \zeta ^* \in K \subseteq F_{\textrm {ad}}. For more general forms of cost functional, i...
{ "cite_spans": [] }
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.05080237612128258, 0.04674428701400757, -0.017361292615532875, -0.008978137746453285, -0.005801082123070955, 0.013532044366002083, 0.04521869122982025, 0.04491357132792473, 0.0018002042779698968, 0.029291458427906036, -0.0524195060133934, -0.01553057599812746, -0.008070407435297966, 0.0...
31072317c9a7de01d17ca702b1b7efec5c121492
subsection
24
45
Full optimal control
To deal with the nonlinearity, we use the estimate\Vert \eta ^{(n)} \eta ^{(n)}_x \Vert _{H_0^{-1}} \le \frac{1}{2} \Vert (\eta ^{(n)})^2 \Vert _{L_0^{2}} \le \frac{1}{2} \Vert \eta ^{(n)} \Vert _{L^{\infty }} \Vert \eta ^{(n)} \Vert _{L_0^{2}} \le \widehat{C}\Vert \eta ^{(n)} \Vert _{H_0^2} \Vert \eta ^{(n)} \Vert _{L...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1007/s00332-005-0720-7", "end": 609, "openalex_id": "https://openalex.org/W1971788399", "raw": "Alexei A Ilyin and Edriss S Titi. Sharp estimates for the number of degrees of freedom for the damped-driven 2-d navier-stokes equations. Jou...
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.04086099565029144, 0.052090905606746674, -0.0027044853195548058, 0.006999619770795107, 0.0026548965834081173, -0.024473875761032104, -0.0026644328609108925, 0.016844861209392548, 0.029310669749975204, -0.0085139786824584, -0.04473653435707092, -0.013350773602724075, 0.01038308721035719, ...
c7221cdce42b6c680478a6399b94d6b5da218905
subsection
25
45
Full optimal control
With this and the weak convergence result (REF a), it follows from Thm 8.1 in (a compactness result) that\eta ^{(n)} \rightarrow \eta ^* \; \textrm {strongly in} \; L^2(0,T;H_0^s), \textrm { for } s < 2.We now check that the weak limits satisfy the control-to-state map, \eta ^* = \eta (\zeta ^*;v) – the pair (\eta ^*,\...
{ "cite_spans": [ { "arxiv_id": "", "doi": "", "end": 204, "openalex_id": "https://openalex.org/W247481854", "raw": "James C Robinson. Infinite-dimensional dynamical systems: an introduction to dissipative parabolic PDEs and the theory of global attractors, volume 28. Cambridge Unive...
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.04696659371256828, 0.042785681784152985, 0.00180149229709059, -0.03646853566169739, 0.00373268430121243, 0.002729418221861124, -0.021896380931138992, 0.03063967451453209, 0.018829360604286194, 0.02830507792532444, -0.03704836964607239, 0.008300787769258022, 0.020889298990368843, -0.0002...
8696994960a00b60552187e13e41dda9edea5e43
subsection
26
45
Full optimal control
Since \lbrace \eta ^{(n)}_t \rbrace _{n=1}^{\infty } is bounded uniformly in L^2(0,T,H_0^{-2}) \subset L^2(0,T,(H_0^{2})^*), it is weakly convergent, and furthermore by a density argument we can conclude that the weak limit is \eta _t^*. Since the sequence \lbrace \zeta ^{(n)}\rbrace _{n=1}^{\infty } converges weakly i...
{ "cite_spans": [ { "arxiv_id": "", "doi": "", "end": 676, "openalex_id": "https://openalex.org/W247481854", "raw": "James C Robinson. Infinite-dimensional dynamical systems: an introduction to dissipative parabolic PDEs and the theory of global attractors, volume 28. Cambridge Unive...
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.034356310963630676, 0.03566831722855568, -0.028009850531816483, -0.0027041099965572357, 0.0067316703498363495, 0.0009773317724466324, -0.0013768458738923073, 0.03142717480659485, -0.0031732292845845222, 0.03514961525797844, -0.07042127847671509, 0.012090308591723442, -0.004447097890079021...
90c0bab22ee976e5241e616d7e3ac3e187489e8a
subsection
27
45
Full optimal control
The first-order conditions of optimality for a local optimiser (\eta ^*, \zeta ^*, p^*) consist of the governing equation (REF ), an adjoint equation, and a variational inequality. The governing equation arises from the functional (Fréchet) derivative of \mathcal {L} with respect to the adjoint variable p, and taking t...
{ "cite_spans": [] }
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.05653554946184158, 0.014874161221086979, -0.03696789965033531, -0.006589963100850582, 0.009959353134036064, 0.022284530103206635, 0.01478258054703474, 0.013836251571774483, 0.029061470180749893, 0.03495313227176666, -0.05980191007256508, 0.040173206478357315, -0.013103608973324299, 0.01...
f449a19dc44d18fbcec785a0bdcee419c85bf826
subsection
28
45
Full optimal control
Note that (REF ) may be written in the form- p_t + \mathcal {A}p = \mathcal {B}^{\prime }(p;\eta ,\overline{\eta }), \qquad \mathcal {B}^{\prime }(p;\eta ,\overline{\eta }) = (I - P_{{0}}) \eta p_x + (-\Delta )^s(\eta - \overline{\eta }) + cp,where \mathcal {A} is defined by (REF a). Thus, the BDF methods outlined in s...
{ "cite_spans": [] }
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.036011919379234314, 0.03552361950278282, -0.047151196748018265, -0.03137309476733208, 0.010963798500597477, -0.011032464914023876, 0.055848993360996246, 0.028367014601826668, 0.01918092370033264, 0.03393665701150894, -0.04275652393698692, 0.04528956487774849, -0.015839140862226486, -0.0...
61e10f65a3bde72ad5f2d9719bfb35d664a9b942
subsection
29
45
Full optimal control
\mathcal {C}_{s,\gamma }(n+1) \ge \mathcal {C}_{s,\gamma }(n) c^{(m)} = c^{(m)}/2 for m \ge n. Update control \zeta ^{(n+1)} =(1 - c^{(n)})\zeta ^{(n)} - c^{(n)} p^{(n)}/\gamma . \eta ^{(n)}, \zeta ^{(n)}. The returned values (\eta ^{(n)},\zeta ^{(n)}) are a minimising sequence as in Theorem REF , with limit approxim...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1201/9781420011418", "end": 905, "openalex_id": "https://openalex.org/W231975775", "raw": "Suzanne Lenhart and John T Workman. Optimal control applied to biological models. Crc Press, 2007.", "source_ref_id": "caea40e69bd2a528998d4...
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.03835967928171158, 0.016692716628313065, -0.056364621967077255, 0.007644471246749163, 0.03787141293287277, -0.010879256762564182, -0.0019702441059052944, 0.03729159012436867, -0.0027121850289404392, 0.05486929789185524, -0.031798556447029114, 0.0017222947208210826, -0.003936673514544964, ...
b40eaee2cc8b152c30619dfe2200d149c6116686
subsection
30
45
Full optimal control
The dotted lines are with points at half-integers represent the gradient descent steps which resulted in larger costs, resulting in step-halving; the faded dashed line taking values on the right axis is the step c^{(n)}.]For the first numerical experiment, we take L_1 = L_2 = 21, and cover the three different dynamical...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1017/jfm.2017.250", "end": 694, "openalex_id": "https://openalex.org/W2559481134", "raw": "R. J. Tomlin, D. T. Papageorgiou, and G. A. Pavliotis. Three-dimensional wave evolution on electrified falling films. Journal of Fluid Mechanics, ...
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.017149755731225014, 0.014410982839763165, -0.0519070029258728, 0.007319924887269735, 0.013884589076042175, 0.018019450828433037, 0.03365868702530861, 0.061275288462638855, -0.0165852177888155, 0.07519039511680603, -0.032346516847610474, 0.015807071700692177, 0.004840534180402756, 0.0132...
91b8da5b10d95512c5b0041c135d94ef1d15adb4
subsection
31
45
Full optimal control
Rows 2 to 4 correspond to the uncontrolled case, with cost components \mathcal {C}_{0,1}^{(1)}, \mathcal {C}_{0,1}^{(2)} (note that \mathcal {C}_{0,1}^{(3)} = 0 for \zeta = 0) and total cost \mathcal {C}_{0,1} – these are observed to be decreasing functions of \kappa . The next four rows give the optimal cost and its b...
{ "cite_spans": [] }
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.026634234935045242, 0.027809500694274902, -0.04582004249095917, 0.025520024821162224, 0.00911211408674717, 0.003960793372243643, 0.009058692492544651, 0.06428848206996918, -0.017934227362275124, 0.048628468066453934, -0.011027641594409943, -0.001595955458469689, 0.004178293514996767, 0....
5af71b328e2b19a8844cd1dc375ada51e5d767ea
subsection
32
45
Full optimal control
We consider three cases, (i),(ii), and (iii), of initial conditions and time-dependent desired states,v = \sin \left(\frac{4\pi x}{L_1} \right) + \delta _{\textrm {(ii)}}\cos \left(\frac{2\pi x}{L_1} + \frac{2\pi y}{L_2} \right), \quad \overline{\eta } = \sin \left(\frac{2\pi (x - t)}{L_1} \right) + \delta _{\textrm {(...
{ "cite_spans": [] }
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.026166779920458794, 0.02046043798327446, -0.05468323081731796, -0.006919320672750473, 0.006064895074814558, 0.09136249870061874, 0.026166779920458794, 0.038906875997781754, 0.02386288344860077, 0.03915099427103996, -0.03841863200068474, -0.00790343526750803, 0.023389896377921104, -0.000...
05676a2f49c4d7438d8ce5ea18d3e41c67403557
subsection
33
45
Full optimal control
For these two cases, the L_0^2-norms of the projections \tilde{P}(\eta ^* - \overline{\eta }) and \tilde{P}\zeta ^* are included in Figure REF (c,d), and visualisations of the time evolution are given in Supplementary Movies 2 (available at https://youtu.be/V24mi-C8n1g) and 3 (available at https://youtu.be/hfcmplP83fQ)...
{ "cite_spans": [] }
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.06079033389687538, 0.022826893255114555, -0.024673186242580414, 0.005702908616513014, 0.016677670180797577, 0.0656120553612709, -0.00989521387964487, 0.0051879300735890865, 0.021041633561253548, 0.020385513082146645, -0.05798275023698807, -0.02986111491918564, -0.02793852984905243, 0.00...
1ac08e0a36631e7b3725bc8d9842136601e89957
subsection
34
45
Transverse mode effects
In this section, we briefly examine the extent to which controlled transverse modes can affect the streamwise and mixed modes through the nonlinear coupling – see the ODE system of Fourier coefficients (REF ). In this way, purely transverse controls (such as those studied in section ) may be thought of as indirect cont...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1098/rspa.2017.0687", "end": 782, "openalex_id": "https://openalex.org/W2795314400", "raw": "R. J. Tomlin, A. Kalogirou, and D. T. Papageorgiou. Nonlinear dynamics of a dispersive anisotropic Kuramoto–Sivashinsky equation in two space di...
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.049795106053352356, 0.024470388889312744, -0.03484436869621277, 0.006689691916108131, -0.008573790080845356, -0.013837059028446674, 0.01650683395564556, 0.04268587753176689, -0.002603030065074563, 0.03804809972643852, -0.0389939621090889, -0.04326559975743294, 0.029993008822202682, -0.0...
525a333633d23fb044704738b851e987c26b62e1
subsection
35
45
Transverse mode effects
Another appealing property of a controlled system would be the regularisation of chaos.The appropriate choice of desired state for this study is \overline{\eta } = (I - \tilde{P}_{\Sigma }) \eta + \tilde{\psi }(y,t), where \Sigma is the set of transverse Fourier modes which we can force (\tilde{P}_{\Sigma } is a projec...
{ "cite_spans": [ { "arxiv_id": "", "doi": "10.1098/rspa.2017.0687", "end": 3116, "openalex_id": "https://openalex.org/W2795314400", "raw": "R. J. Tomlin, A. Kalogirou, and D. T. Papageorgiou. Nonlinear dynamics of a dispersive anisotropic Kuramoto–Sivashinsky equation in two space d...
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.006633993238210678, 0.0240029226988554, -0.053163498640060425, 0.013168800622224808, 0.0004370367096271366, -0.018204377964138985, 0.014755770564079285, 0.02124098502099514, 0.025849303230643272, 0.06708000600337982, -0.018295934423804283, 0.009605747647583485, 0.0154729587957263, 0.006...
ee1eceea4f16c344a7be2a236d826d3dd9585416
subsection
36
45
Transverse mode effects
Panel (a) shows that an increase in A results in decay of the energy density of \eta - \tilde{\eta } (this decrease is monotonic in most cases). Furthermore, we find that the chaotic dynamics are eventually regularised for a sufficiently large value of A, and the transverse wave eventually becomes nonlinearly stable wh...
{ "cite_spans": [] }
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.028829840943217278, 0.03815490007400513, -0.04923507943749428, -0.020832573994994164, 0.007138781249523163, -0.020924145355820656, 0.006593166384845972, 0.022679271176457405, 0.02216036431491375, 0.042977675795555115, -0.013667084276676178, 0.0076080868020653725, 0.01645239256322384, -0...
34f0b3408ca62659d3ea818b04658ddf2443a10e
subsection
37
45
Transverse mode effects
In terms of the infinite-dimensional system of Fourier modes, the linearisation of (REF ) about \eta = \tilde{\eta } = \tilde{\psi } for a general \tilde{\psi }(y,t) is\frac{\mathrm {d}}{\mathrm {d}t}\eta _{{m}} = - i\tilde{m}_1 \sum _{l_2\in \mathbb {Z}} \eta _{(m_1, m_2 - l_2)} \tilde{\psi }_{l_2} + \left[ (1-\kappa ...
{ "cite_spans": [] }
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.04655979573726654, 0.02710902877151966, -0.03957277536392212, -0.006903115194290876, 0.013325681909918785, -0.01888631284236908, -0.005354681517928839, 0.031182248145341873, 0.05519440770149231, 0.04140343517065048, -0.02608690969645977, -0.0034000701270997524, 0.036704741418361664, 0.0...
d245b7391955d88ec46d7a7c96881f496ecdb1af
subsection
38
45
Conclusions
In this paper we considered the distributed control of a Kuramoto–Sivashinsky equation for gravity-driven thin film flow overlying or hanging from a 2D flat substrate. Blowing and suction controls applied at the substrate surface appear as a forcing term in the weakly-nonlinear evolution equation.For hanging films (\ka...
{ "cite_spans": [] }
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.04976291209459305, 0.021982941776514053, -0.03713149204850197, 0.02881733328104019, -0.014492570422589779, 0.02720026671886444, 0.004347770940512419, 0.025644222274422646, -0.010480416938662529, 0.04439303278923035, -0.02687990479171276, -0.0043248883448541164, 0.017940277233719826, 0.0...
86c85dc37b3d7d06ce5080ea5d736aa1ca8a2938
subsection
39
45
Conclusions
With extensive numerical simulations, we found that small amplitude sinusoidal transverse waves yielded a decrease in the average energy of the fluid interface, with large amplitude waves being nonlinearly stable, regularising the chaotic dynamics.A large motivation for this paper and current work by the authors is in ...
{ "cite_spans": [] }
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.013849113136529922, 0.03629001975059509, -0.04495811462402344, -0.023822002112865448, -0.018923306837677956, -0.034153517335653305, 0.03223066404461861, 0.013040294870734215, 0.0190301313996315, 0.04547697678208351, 0.0005398483481258154, -0.01438323874026537, 0.013078446500003338, -0.0...
e3886b6015720aade7df771fa228a00ce1767a91
subsection
40
45
Derivation of optimal transverse control
We now give a brief derivation of the optimal control for an LQR tracker problem for the transverse system (REF ). We consider the general desired state\overline{\eta } = (I -\tilde{P}_{\Sigma }) \eta + \tilde{\psi }(y,t), \qquad \tilde{\psi }(y,t) = \sum _{k_2 \in \Sigma } \tilde{\psi }_{k_2}(t) e^{i\tilde{k}_2 y}.Her...
{ "cite_spans": [] }
1805.08236
Optimal control of thin liquid films and transverse mode effects
[ "Ruben J. Tomlin", "Susana N. Gomes", "Grigorios A. Pavliotis", "Demetrios T. Papageorgiou" ]
[ "physics.flu-dyn" ]
2,018
en
Physics
[ -0.04471592977643013, 0.019946662709116936, -0.035040196031332016, 0.01874101161956787, -0.019351467490196228, 0.014658584259450436, 0.006314408499747515, 0.009927546605467796, 0.022510578855872154, 0.059580542147159576, -0.03114853799343109, 0.027180571109056473, 0.014101542532444, 0.0390...