text stringlengths 16 3.88k | source stringlengths 60 201 |
|---|---|
system Hamiltonian, which means that energy of the center of mass is
conserved and can be used to label states. Then the Hamiltonian above breaks into two
independent problems – one for center of mass and another one for relative motion:
Hˆ
CM ,
Hˆ
CMu ECMu
Hˆ
Hˆ
r 0
ru Eru
ˆ Hu EC... | https://ocw.mit.edu/courses/3-024-electronic-optical-and-magnetic-properties-of-materials-spring-2013/5c2116c92a8c7204af60846da432d6b5_MIT3_024S13_2012lec9.pdf |
�
2
1
tan sin2 2
1
e2
r
3
IV Finding the eigenfunctions and eigenvalues of the Hamiltonian.
2
1
tan sin2 2
1
e2
r
Hˆ rˆ, pˆ
r
2
1 2
2 r r
1 2
2
2 r r
2
r
2
2
1 2
r 2
Lˆ2
2r
r
Hˆ rˆ, pˆ... | https://ocw.mit.edu/courses/3-024-electronic-optical-and-magnetic-properties-of-materials-spring-2013/5c2116c92a8c7204af60846da432d6b5_MIT3_024S13_2012lec9.pdf |
�r
2 r
Lˆ2
2r
e2
u r,, Eu r,,
r
2
Note that the angular momentum squared operator commutes with the Hamiltonian and recall
that it also commutes with the z-component of the angular momentum; consequently we can
simultaneously solve the following equations:
Lˆ
zu r,, mu r,,
... | https://ocw.mit.edu/courses/3-024-electronic-optical-and-magnetic-properties-of-materials-spring-2013/5c2116c92a8c7204af60846da432d6b5_MIT3_024S13_2012lec9.pdf |
number.
Substituting the function above into the time-independent Schrodinger’s equation (Hamiltonian
eigenvalue problem) we get:
r
2
2l l 1
e
Rnl EnlRnl
r
2r 2
r
2 1 2
2 r r 2
We can identify a kinetic energy term and an effective potential energy, which is related to ... | https://ocw.mit.edu/courses/3-024-electronic-optical-and-magnetic-properties-of-materials-spring-2013/5c2116c92a8c7204af60846da432d6b5_MIT3_024S13_2012lec9.pdf |
�� Lnl1
, n l, n 0
Where L2l1 is the generalized Laguerre polynomials. Substituting it into Mathematica, we can
nl1
find the Bohr radius:
2
a0
e2
0.529 A
Example of atomic orbitals – 1s: u100 r,, R10 r
Y0
, 2 a0
0
r
a0
3
2 e
1
4
Labeling of states – quantum number... | https://ocw.mit.edu/courses/3-024-electronic-optical-and-magnetic-properties-of-materials-spring-2013/5c2116c92a8c7204af60846da432d6b5_MIT3_024S13_2012lec9.pdf |
.
4. To each value of l correspond (2l+1) values of m: m=-l,-l+1..., l–1,l.
Each sub-shell contains (2l+1) eigenfunctions or states.
5. The levels of En are n2 degenerate: 2l 1 n2
ln1
l0
6. The eigenfunctions common to Lˆ
z, Lˆ2, Hˆ unlm r,, are completely defined by
�specifying three numbers, whi... | https://ocw.mit.edu/courses/3-024-electronic-optical-and-magnetic-properties-of-materials-spring-2013/5c2116c92a8c7204af60846da432d6b5_MIT3_024S13_2012lec9.pdf |
.024 Electronic, Optical and Magnetic Properties of Materials
Spring 2013
For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms. | https://ocw.mit.edu/courses/3-024-electronic-optical-and-magnetic-properties-of-materials-spring-2013/5c2116c92a8c7204af60846da432d6b5_MIT3_024S13_2012lec9.pdf |
Introduction to Robotics, H. Harry Asada
1
Chapter 3
Robot Mechanisms
A robot is a machine capable of physical motion for interacting with the environment.
Physical interactions include manipulation, locomotion, and any other tasks changing the state of
the environment or the state of the robot relative to the env... | https://ocw.mit.edu/courses/2-12-introduction-to-robotics-fall-2005/5c238d7e3445337ed40d4af83d9d2239_chapter3.pdf |
is to locate its end-
effecter, e.g. a hand, a leg, or any other part of the body performing a task, in three-dimensional
space. If the kinematic structure of such a robot mechanism is analogous to a coordinate system,
1 It is interesting to note that all biological creatures are made of revolute type joints; there a... | https://ocw.mit.edu/courses/2-12-introduction-to-robotics-fall-2005/5c238d7e3445337ed40d4af83d9d2239_chapter3.pdf |
3
3
3
3
3
3
x
x
x
x
x
x
x
x
x
x
x
x
z
z
z
z
z
z
z
z
z
z
z
z
0
0
0
0
0
0
0
0
0
0
0
0
Figure 3.1.2 Cartesian coordinate robot
Figure by MIT OCW.
Photo removed for copyright reasons.
GMF Robotics model M-100.
Figure 3.1.3 Cylindrical coordinate robot
Figure by MIT OCW.
Department of Mechanical Engineering
Massachusett... | https://ocw.mit.edu/courses/2-12-introduction-to-robotics-fall-2005/5c238d7e3445337ed40d4af83d9d2239_chapter3.pdf |
has a great degree of flexibility and
versatility, being the most standard structure of robot manipulators. The third kinematic structure,
also consisting of three revolute joints, has a unique mass balancing structure. The counter
balance at the elbow eliminates gravity load for all three joints, thus reducing toqu... | https://ocw.mit.edu/courses/2-12-introduction-to-robotics-fall-2005/5c238d7e3445337ed40d4af83d9d2239_chapter3.pdf |
Driving joints 1
and 3 with two actuators, we can move the end-effecter within the vertical plane. It should be
noted that, if more than two joints were actively driven by independent actuators, a conflict
among three actuators would occur due to the closed-loop kinematic chain. Three of the five
joints should be p... | https://ocw.mit.edu/courses/2-12-introduction-to-robotics-fall-2005/5c238d7e3445337ed40d4af83d9d2239_chapter3.pdf |
(Spherical Joint)
(Spherical Joint)
(Spherical Joint)
(Spherical Joint)
(Spherical Joint)
(Spherical Joint)
(Spherical Joint)
(Spherical Joint)
(Spherical Joint)
(Spherical Joint)
(Spherical Joint)
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
(Prismatic Joint)
(Prismatic Joint)
(Prismatic Joint)
(Prismatic Joint)
(Pr... | https://ocw.mit.edu/courses/2-12-introduction-to-robotics-fall-2005/5c238d7e3445337ed40d4af83d9d2239_chapter3.pdf |
S
S
S
S
S
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
Fixed
Fixed
Fix... | https://ocw.mit.edu/courses/2-12-introduction-to-robotics-fall-2005/5c238d7e3445337ed40d4af83d9d2239_chapter3.pdf |
Lecture 02
Voting classifiers, training error of boosting.
18.465
In this lecture we consider the classification problem, i.e. Y = {−1, +1}.
Consider a family of weak classifiers
H = {h : X → {−1, +1}}.
Let the empirical minimizer be
h0 = argmin
1
n
n
Xi=1
I(h(Xi) 6= Yi)
and assume its expected error,
1
2
> ε = Error(h0),... | https://ocw.mit.edu/courses/18-465-topics-in-statistics-statistical-learning-theory-spring-2007/5c28ad9411d2f7ad6c2d74583d965522_lecture02.pdf |
2.1. Let γt = 1/2 − εt (how much better ht is than tossing a coin). Then
1
n
n
Xi=1
T
I(f (Xi) 6= Yi) ≤
1 − 4γ2
t
Yt=1 p
Proof.
I(f (Xi) 6= Yi) = I(Yif (Xi) = −1) = I(Yi
αtht(Xi) ≤ 0) ≤ e−Yi P
T
t=1 αtht(Xi)
T
Xt=1
Consider how weight of example i changes:
wT +1(i) =
wT (i)e−YiαT hT (Xi)
Zt
=
. . .
=
e−YiαT hT (Xi)
Zt
... | https://ocw.mit.edu/courses/18-465-topics-in-statistics-statistical-learning-theory-spring-2007/5c28ad9411d2f7ad6c2d74583d965522_lecture02.pdf |
3.46 PHOTONIC MATERIALS AND DEVICES
Lecture 14: Defects and Strain
Lecture
Notes
Perfection
• LRO (Long Range Order)
• SRO (Short Range Order)
Imperfection
• Vibrating atom
• Electronic change
• Chemical impurity
• Point defect
• 1D defect
• 2D defect
• 3D defect
(I, V)
(dislocation)
(grain boundary)
... | https://ocw.mit.edu/courses/3-46-photonic-materials-and-devices-spring-2006/5c303cb9b7be85a43704cb20f73d045d_3_46l14_defects.pdf |
⎝ k T ⎠
B
C
Point Defect Equilibria in Compounds
bB + cC U dD + eE
]d [D E]e
[
]b [
B C]c
[
K =
ABx Compounds
Schottky Defect
(vacancy pair)
A A + xBB U VA + xV + A A + BB
B
KS = [V ][VB ]x
A
Frenkel Pair
A A → A I + VA
KFP ( ) = [A ][VA ]
A
FP ( ) = [B ][VB ]
K
B
I
I
Anti-Site Defect
A A
+ BB U AB... | https://ocw.mit.edu/courses/3-46-photonic-materials-and-devices-spring-2006/5c303cb9b7be85a43704cb20f73d045d_3_46l14_defects.pdf |
+
⇒ solubility ≡ f (EF)
example: Li in Si (B)
BSi R BSi + h
−
+
Li ext ) R Li
(
+ + e−
I
−
+
e + h U bond
+ ⎤
⎤
−⎡BSi
⎥ + = ⎡
⎥ + p
⎢LiI
⎦ n
⎢⎣
⎦
⎣
3.46 Photonic Materials and Devices
Prof. Lionel C. Kimerling
Lecture 14: Defects and Strain
Page 4 of 5
Notes
Lecture
T1
T
1
siB−⎡
⎢... | https://ocw.mit.edu/courses/3-46-photonic-materials-and-devices-spring-2006/5c303cb9b7be85a43704cb20f73d045d_3_46l14_defects.pdf |
Copyright
c
Nancy Leveson, Sept. 1999
1980s:
OO design: added inheritance, multiple inheritance, and
polymorphism to ADT.
In process added complexity and increased
some types of connectivity.
Lots of claimed advantages -- so far empirical
evaluation is not supporting them well.
1990s:
Architecture
Patterns ... | https://ocw.mit.edu/courses/16-355j-software-engineering-concepts-fall-2005/5c4493536832111845f291d3d62a6f38_cnotes5.pdf |
modify.
4. Restricted visibility
Locality of information
Copyright
c
Nancy Leveson, Sept. 1999
General Software Design Concepts
Implementations of the general principles
Decomposition
Can decompose with respect to time order, data flow,
logical groupings, access to a common resource,
control flow, or some ... | https://ocw.mit.edu/courses/16-355j-software-engineering-concepts-fall-2005/5c4493536832111845f291d3d62a6f38_cnotes5.pdf |
straction handled through information hiding
Hierarchy by defining uses and is-composed-of relations
Minimize connectivity
General Software Design Concepts (5)
Modularity (con’t.)
Copyright
c
Nancy Leveson, Sept. 1999
Sample things to modularize and encapsulate:
abstract data types
algorithms (e.g., sort)... | https://ocw.mit.edu/courses/16-355j-software-engineering-concepts-fall-2005/5c4493536832111845f291d3d62a6f38_cnotes5.pdf |
solutions will most likely come from systematically following a
prescriptive procedural method.
60s and 70s: people recognized that a systematic approach to
development needed to cope with large-scale projects. Needed
a way to promulgate and encourage the adoption of desirable
practices.
A procedural form (do thi... | https://ocw.mit.edu/courses/16-355j-software-engineering-concepts-fall-2005/5c4493536832111845f291d3d62a6f38_cnotes5.pdf |
Electricity and Magnetism
• Review
– Electric Charge and Coulomb’s Force
– Electric Field and Field Lines
– Superposition principle
– E.S. Induction
– Electric Dipole
– Electric Flux and Gauss’ Law
– Electric Potential Energy and Electric Potential
– Conductors, Isolators and Semi-Conductors
Feb 27 2002
Today
• Fast s... | https://ocw.mit.edu/courses/8-02x-physics-ii-electricity-magnetism-with-an-experimental-focus-spring-2005/5c48da61d3532b22af63ad3792b99f6b_2_27_2002_edited.pdf |
!
Feb 27 2002
Electric Field
• New concept – Electric Field E
• Charge Q gives rise to a Vector Field
• E is defined by strength and direction of
force on small test charge q
Feb 27 2002
The Electric Field
• Electric Field also exists is test charge q is not
present
• The charge Q gives rise to a property of space ... | https://ocw.mit.edu/courses/8-02x-physics-ii-electricity-magnetism-with-an-experimental-focus-spring-2005/5c48da61d3532b22af63ad3792b99f6b_2_27_2002_edited.pdf |
• True for ANY closed surface around Qencl
• Relates charges (cause) and field (effect)
Feb 27 2002
Gauss’ Law
• Different uses for Gauss’ Law
– Field E -> Qencl (e.g. conductor)
– Qencl -> Field E (e.g. charged sphere)
• Proper choice of surface – use symmetries
Feb 27 2002
Hollow conducting Sphere
+
+
+
+
+
+
+
+
+... | https://ocw.mit.edu/courses/8-02x-physics-ii-electricity-magnetism-with-an-experimental-focus-spring-2005/5c48da61d3532b22af63ad3792b99f6b_2_27_2002_edited.pdf |
b
• Ex.: Single Charge
Feb 27 2002
Electric Potential for many
charges
• Superposition principle....
V(x) = Σ1/(4πε0) Qi/ri
• Sum of scalars, not vectors!
• Integral for continous distributions
Feb 27 2002
Example: Three charges
Q2
Q1
r2
r1
Q3
r3
x
Feb 27 2002
V(x) = Σ1/(4πε0) Qi/ri
Example: Capacitor plates
+
+
+
... | https://ocw.mit.edu/courses/8-02x-physics-ii-electricity-magnetism-with-an-experimental-focus-spring-2005/5c48da61d3532b22af63ad3792b99f6b_2_27_2002_edited.pdf |
6.012 Electronic Devices and Circuits
Comments on Photoconductive Detectors - 9/17/09 Version
Photoconductivity was first reported in 1873 by W. Smith [J. Soc.
Telegraph Eng., Vol. 2 (1873) p. 31], making it one of the first properties of
semiconductors to be studied and exploited. At the same time, some of the
new... | https://ocw.mit.edu/courses/6-012-microelectronic-devices-and-circuits-fall-2009/5c58a51e629ef0505139e7a4cf72f2fd_MIT6_012F09_lec03_photo.pdf |
ize the
donor corresponds to that of the infrared light of interest. Unlike the column V
donors we discussed in class, these donors are not normally ionized at room
temperature; it is the incident light that ionizes them, leading to an increased
conductivity, i.e., photoconductivity. These detectors are called extrin... | https://ocw.mit.edu/courses/6-012-microelectronic-devices-and-circuits-fall-2009/5c58a51e629ef0505139e7a4cf72f2fd_MIT6_012F09_lec03_photo.pdf |
points in space like donor
traditional
ions).
photoconductor, but in exchange for the increased complexity one gains much
more
the performance and spectral response
characteristics of the devices.
They are structurally much more complex
in designing
flexibility
than a
Note to students: You are not responsible... | https://ocw.mit.edu/courses/6-012-microelectronic-devices-and-circuits-fall-2009/5c58a51e629ef0505139e7a4cf72f2fd_MIT6_012F09_lec03_photo.pdf |
Three Lectures on
Organizational Structures
• Lecture 1 - Typology of generic
organizational architectures
– Their advantages and disadvantages
• Lecture 2 - Simple models of complexity
and flexibility; their relationship to each
other for each of the generic architectures
• Lecture 3 - Relationships of generic
ar... | https://ocw.mit.edu/courses/esd-342-network-representations-of-complex-engineering-systems-spring-2010/5c5b67ad949c857a0932e37036533a63_MITESD_342S10_lec08.pdf |
others ought to be
able to take over their role; they can handle many
classes of changes in specs with relative ease
• Human teams are relatively small in size – volume of
output is limited in scale and scope; 7±2 limits (George
Miller - 1956); however, output can be large given
enough time (one person, Richard St... | https://ocw.mit.edu/courses/esd-342-network-representations-of-complex-engineering-systems-spring-2010/5c5b67ad949c857a0932e37036533a63_MITESD_342S10_lec08.pdf |
is not too problematic most of the time due to
understanding of context (e.g., mathematicians don’t
usually get confused about 0, even when it means a 2x2
matrix whose entries are all 0)
• Hierarchies have no cycles, except within a single layer
9
Non-standard trees
• An impure tree with non-standard interconnectio... | https://ocw.mit.edu/courses/esd-342-network-representations-of-complex-engineering-systems-spring-2010/5c5b67ad949c857a0932e37036533a63_MITESD_342S10_lec08.pdf |
the US. We’ll discuss this later in the term.
Layer 1
Layer 2
Layer 3
An example is matrix addition and multiplication,
based on vector procedures, which are based on element arithmetic
14
Characteristics of Generic Layered
Structures
• Technical systems that use layering, such as the Internet
or many software syst... | https://ocw.mit.edu/courses/esd-342-network-representations-of-complex-engineering-systems-spring-2010/5c5b67ad949c857a0932e37036533a63_MITESD_342S10_lec08.pdf |
mechanisms for reducing complexity
Industries, such as health care or university education,
can be viewed as layered – we’ll discuss this later
•
• Three layers are very common in human organizations
and industries
18
Variations on Layered Systems
• Layered systems can have high complexity due to the
potentially la... | https://ocw.mit.edu/courses/esd-342-network-representations-of-complex-engineering-systems-spring-2010/5c5b67ad949c857a0932e37036533a63_MITESD_342S10_lec08.pdf |
are discoveries that
reduce the loss of performance
• For example, good compilers have made compiled
FORTRAN code more efficient than almost any human-
produced code. RISC computers have made it
essentially impossible for humans to generate better
code than compilers
• One can also permit the breaking though of the... | https://ocw.mit.edu/courses/esd-342-network-representations-of-complex-engineering-systems-spring-2010/5c5b67ad949c857a0932e37036533a63_MITESD_342S10_lec08.pdf |
)
25
Overlays
• Large partnerships (e.g., consulting firms) are
often layered, and use project teams that may
be best modeled as tree structures which are
overlayed on the base structure
• Matrix organizations (two bosses) may be
viewed as overlays as well. At MIT we have
departments as well as centers, and most ... | https://ocw.mit.edu/courses/esd-342-network-representations-of-complex-engineering-systems-spring-2010/5c5b67ad949c857a0932e37036533a63_MITESD_342S10_lec08.pdf |
)
• Pure tree structures will have relatively low complexity (good) and
very low flexibility (not good) considering their size
• Pure grid networks will often have relatively low complexity and very
high flexibility (and thus some robustness), but likely low control
• Layered structures will have intermediate level o... | https://ocw.mit.edu/courses/esd-342-network-representations-of-complex-engineering-systems-spring-2010/5c5b67ad949c857a0932e37036533a63_MITESD_342S10_lec08.pdf |
are closer to their medieval past and its cooperative
aspects
• More on this point later in the term
34
MIT OpenCourseWare
http://ocw.mit.edu
ESD.342 Network Representations of Complex Engineering Systems
Spring 2010
For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms. | https://ocw.mit.edu/courses/esd-342-network-representations-of-complex-engineering-systems-spring-2010/5c5b67ad949c857a0932e37036533a63_MITESD_342S10_lec08.pdf |
20.330 / 6.023 / 2.793 Fields, Forces and Flows in Biological Systems
Instructors: Jongyoon “Jay” Han and Scott Manalis
TOPICS
Introduction to electric fields
Maxwell’s equations
Introduction to fluid flows
Transport phenomena in biological systems
Electro-quasistatics
Electrokinetics
Electrophoresis
Van der ... | https://ocw.mit.edu/courses/20-330j-fields-forces-and-flows-in-biological-systems-spring-2007/5c643ae047c6ae6f7ecaa1e0855ae03c_lec1.pdf |
http://www.aip.org/pt/jan00/berg.htm
Measuring binding kinetics
Surface Plasmon Resonance (Biacore)
Courtesy of Biacore. Used with permission.
Label-free enables direct readout of Kon and Koff
target
n
o
i
t
p
r
o
s
d
a
capture
surface
on
off
time
binding rate
constant
Detecting biomolecules on the nanoscale... | https://ocw.mit.edu/courses/20-330j-fields-forces-and-flows-in-biological-systems-spring-2007/5c643ae047c6ae6f7ecaa1e0855ae03c_lec1.pdf |
Mediation in the Homing Pigeon." Nature 432 (2004): 508-511.
Introduction 2 : Cancer targeting using nanoparticles
Gao, Cui, Levenson, Chung and Nie, Nature Biotechnology 22, 969 (2004)
Courtesy of Leland W. K. Chung. Used with permission.
Courtesy of Leland W. K. Chung. Used with permission.
Courtesy of Leland W. ... | https://ocw.mit.edu/courses/20-330j-fields-forces-and-flows-in-biological-systems-spring-2007/5c643ae047c6ae6f7ecaa1e0855ae03c_lec1.pdf |
Massachusetts Institute of Technology
6.270 Autonomous LEGO Robot Competition
IAP 2005: Attack of the Drones
Workshop 4 — Code & Sensors I: Basic Control and Robot Skills
Wednesday, January 5, and Thursday, January 6, 2005
1
Items to Bring
• Handy Board with Expansion Board
2 Reading
• Handy Board technical ma... | https://ocw.mit.edu/courses/6-270-autonomous-robot-design-competition-january-iap-2005/5c6455005827275583dca5a9083664f2_4_codesensors1.pdf |
for assistance with the various functions. When
you are done with your program, type:
<Ctrl>-x <Ctrl>-c
• You will be prompted as to whether or not to save the file under the previously assigned name. Hit “y”.
• You should now return a terminal window.
• At the C> prompt, type “unload” followed by the name(s) of the... | https://ocw.mit.edu/courses/6-270-autonomous-robot-design-competition-january-iap-2005/5c6455005827275583dca5a9083664f2_4_codesensors1.pdf |
MIT OpenCourseWare
http://ocw.mit.edu
6.046J / 18.410J Design and Analysis of Algorithms
Spring 2015
For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms. | https://ocw.mit.edu/courses/6-046j-design-and-analysis-of-algorithms-spring-2015/5c6cf10a900ea288d97dce247a9a5a9d_MIT6_046JS15_writtenlec2.pdf |
ALPHA DRAFT- For Review Only
Space Systems, Policy, and Architecture Research Consortium
(SSPARC)
Draft 11/4/03
“SSPARC BOOK” MATERIAL
for Lecture 3
Prepared by:
Hugh McManus
Metis Design
----
Draft for evaluation only. Do not distruibute.
© 2003 Massachusetts Institute of Technology
11/6/03
1
ALPHA DRAFT- For Review ... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
uman, Tim
Spaulding, Dave Stagney, Dan Thunnissen, Myles Walton, Annalisa Wiegel, and Brandon
Wood, along with their advisors and committees. Many other students, staff, and undergraduate
researchers also contributed. Bill Borer, Kevin Ray, and John Ballenthin of the Air Force
Research Laboratory, Steve Wall of NASA JP... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
Satellite X (X-TOS)14.........................17
Running Example two: general purpose orbit transfer and servicing vehicle
(SpaceTug) ..............................................................................................................21
3. DETAILED DESCRIPTION OF MATE-CON PROCESS................................. | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
80% of the
eventual costs of a system are determined before the first 20% of the funds have actually been
spent.3 Figure 1 illustrates this graphically. It is therefore not surprising that programs that
under-fund front-end work (from mission feasibility through preliminary design) will have
higher costs later in the p... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
been developing effective systems for about fifty years and
their accomplishments are a testament to human ingenuity. In addition to tackling the
complex technical challenges in building these systems, engineers must also cope with
the changing political and economic context for space system design and development.
The... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
consideration of
other options; 2) Inadequate technical feasibility studies in the early stages of design; 3)
Insufficient regard for the preferences of key decision makers; 4) Disconnects between
perceived and actual decision maker preferences; 5) Pursuit of a detailed design without
understanding the effects on the l... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
CON is a process for understanding both the possibilities and the difficulties when
looking for solutions to complex problems. Its intent is to allow informed upfront decisions and
planning, so that the detailed design process which follows is aimed at the right solution, and is
forewarned of potential problems and for... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
Technology
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ALPHA DRAFT- For Review Only
In this section we will walk through a quick introduction the steps in the process. The MATE
process, exploration of the resulting tradespace, an the Concurrent Engineering process will be
described with detailed step-by-step instruction in how to carry them out in the... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
and illustrates a key feature of the entire method—that it is driven by a set of
quantified user needs, rather than requirements pertaining to a specific system. The attributes
ideally need to be complete (capture all important user needs) and independent; this is sometimes
hard to accomplish at the beginning of a stud... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
architecture. To keep the analyses
tractable, this vector must be limited to those variables that will have the largest effect on the
attributes. The design vector may need to be revisited as the models mature.9 Often, the exercise
of picking the design vector is one of exclusion, as variables of undoubted importance i... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
minimum, the desire is to reduce the trade space to designs worth considering, uncover the
controlling physics or other constraints, and uncover the key design trades.
Data visualization and manipulation techniques are usually needed, along with patience and
curiosity, to understand the complex lessons of the design sp... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
accuracies. Finally, there may be uncertainties or risks inherent in the mission to be
performed. All of these can be included in the tradespace analysis using tools to be explored
later in this book. As an introduction, consider the first twelve pages of an unpublished paper by
Hastings, Weigel and Walton.13
The proce... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
been selected, rapid development of a design or set of vehicle designs is
done using ICE. An interdisciplinary team with tools that communicate seamlessly through a
common database does design sessions in physical or at least virtual co-location. Figure 7 shows
the computer tools, referred to as sheets, linked to a ser... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
by direct user/customer involvement in the ICE
session. ICE becomes MATE-CON with the inclusion of a MATE chair that has the results, and
often the models, of the preceding MATE effort at his or her fingertips. The MATE chair can
quantitatively assess the progress of the design not just towards meeting requirements, bu... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
1%
Power
11%
Propellant
36%
Propulsion
(dry)
2%
Structures &
Mechanisms
18%
Thermal
5%
Mating
System
27%
Figure 8 Typical ICE output: vehicle configuration and mass budget for an electric propulsion
orbital transfer vehicle.16
ICE methods can be used for more detailed design studies, up to and including creating har... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
methods described here is far from stable. In this work, the
architectural-level trade space exploration is referred to as MATE, the rapid conceptual design
process as ICE, and the integrated process as MATE-CON. The MATE method is an expansion
of the Generalized Information Network Analysis (GINA) method, and many of ... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
potential value of the system (and even its physical feasibility)
are not well reflected by the requirements.26 To this, we add the observation that most
requirements are written with a solution to the design problem in mind, and hence reinforce the
premature narrowing of the design space that we attempt to avoid. For ... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
being addressed. Changes in these selections late in the process may require substantial
“rework.” The definition of the trade space requires models with the right fidelity. They must
capture the factors that differentiate the architectures under consideration without being
computationally intractable or excessively di... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
characteristics of the data collected: its time span
(time between the very first data point collected and the very last), altitude, maximum latitude,
latency (from collection to useful presentation to user), and the percentage of the data collected
at or near the equator.
The solution space (design vector) was reduced... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
changing the utilities and repeating the entire analysis, resulting
in a revised trade space. This re-analysis took less than a day, using the pre-existing models.
The MATE trade space was used to drive an ICE session to design vehicles for X-TOS. The ICE
vehicle design trades reflected the MATE trades of orbit and re-... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
is
a specific
architecture
Total Lifecycle Cost ($M)
Figure 10 MATE process for X-TOS
© 2003 Massachusetts Institute of Technology
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19
ALPHA DRAFT- For Review Only
Figure 11 ICE result: X-TOS vehicle CAD model
© 2003 Massachusetts Institute of Technology
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ALPHA DRAFT- For Review Only
2.7.
Running ... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
etermines at a high level what it can do to interact with targets, referred to here as its capability;
and (3) response time, or how fast it can get to a potential target and interact with it in the desired
way.
These attributes are translated into a single utility function. In the absence of real users from
which to c... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
capability, rapid response system; electric monsters (not shown) might be interesting to users not
interested in rapid response time. A final range of vehicles occupies the lower left region of the
Pareto front. These are cost effective vehicles build using existing technology (e.g. storable bi-
propellant systems) tha... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
• Propulsion system
• Mass of
observing/grappling/control
equipment
Fuel load
•
System Model
•
•
Rocket Equation
Parametric vehicle sizing relations
•
Calculate Utility
Parametric – many potential utilities
considered
Estimate Cost
Simple mass-based model
•
2000
1800
1600
1400
1200
1000
800
600
400
200
)
M
$
(
t
s... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
, before proceeding. With this understanding, it
should be possible to work the following sections more-or-less sequentially.
The two running examples will continue in detail on a section-by-section basis. The two
examples illustrate two quite different approaches to the process, in terms of the type of mission
studied... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
If, on the
other hand, the desire is to create a new capability, the interested stakeholders may not be the
final users. The motivation may be described as technology or concept “push”, with a set of
stakeholders interested in creating a capability, with the hope that if it exists it will create market
demand. In this ... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
to quickly arrive at a system architecture and vehicle design that will respond to the user’s needs.
Space Tug, on the other hand, includes a large space of possible solutions, but is scoped in terms
of the aspects of the problem to be considered and the level of detail of the solutions to be
developed.
4.3.
Identify ... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
Customer “is an individual or
organization that (1) commission the engineering of a system, or (2) is a prospective purchaser of
an end product.” The Customer typically has preferences that balance product performance
meeting User needs, cost of the system, and political considerations. This decision maker
typically co... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
4.4. X TOS Need, Concept and Scope32,35
The X-TOS project was motivated by the need for improved predictions of drag on orbiting
bodies. This drag is a strong function of the density of the upper atmosphere, which itself is a
complex function of seasonal, solar cycle, and other conditions. The general purpose of the X-... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
of data useful to the developers
of the as-yet incomplete models.
The framework in Figure 13 was modified to capture the relationships for this project. The
equivalent stakeholders were:
Designer:
User:
Firm:
Customer:
External:
Space System Design course students
Air Force Research Lab (AFRL/Hanscom, Dr. John Ballenth... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
considered. Key issues involving the equipment and software
necessary to perform orbital servicing and mating were considered in a separate study. This
equipment was treated as a generic capability, which interfaced with the vehicle by having mass,
and consuming power and communications bandwidth. Except for the commun... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
chosen to correctly represent the aspects of the system that
the user cares about, and must have certain features (such as perceived independence) that will
allow them to work as bases for a utility analysis. The utility functions are dimensionless
representations of the relative desirability of various values of the a... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
the infinite possible solutions;
the simulation space is a tractable model of the proposed systems in action, and the solution
space is the necessarily approximate result. At an early stage in the design or architecting
process, these approximations are necessarily rather coarse. It is therefore vital that the trade
© ... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
maker being assessed has a preference for different levels of that
attribute in a well-defined context.
Attributes have a number of characteristics that must be explicitly determined through
interactions with the decision maker. Attributes have a definition, units, range, and a direction of
increasing value. All of the... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
be developed simply by “floating” a set of
functional requirements over a range of values.
© 2003 Massachusetts Institute of Technology
11/6/03
34
ALPHA DRAFT- For Review Only
Table 1: Examples of Attributes
ATOS:9
Equatorial Survey: presence of vehicle(s) in equatorial zone
Equatorial Snapshot: complex function of re... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
(detailed definition application dependent):39
Quantity
Quality
Coverage
Timeliness
Availability
© 2003 Massachusetts Institute of Technology
11/6/03
35
ALPHA DRAFT- For Review Only
The attributes will be used to determine the utility of the system to the user. In order to facilitate
the use of formal utility theory (... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
defined
in the next section.
Ideally, attributes describe a function or output of a system. Thinking functionally is sometime
difficult, especially for those with experience in traditional design methods. Functional thinking
is key to defining concept-independent attributes that will not inherently bias later evaluatio... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
concerned with a few of the highest-level functions of the system or systems. If brainstorming
produces too many attributes, it is likely that the group is thinking at too detailed a level.*
Finalizing Attribute Definitions
The attributes will need to be iterated with stakeholders. They will be reevaluated in light of
... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
Cost may be thought of as an attribute, but in the examples given here it is treated somewhat
differently. It is clearly quantifiable, and has an obvious direction of preference (lower is better).
However, defining upper and lower bounds on cost during concept exploration will be arbitrary
and may be excessively restri... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
scientists cared about all of these aspects of the data. This interest
was quantified by brainstorming with the user a preliminary set of attributes:
Knowledge/Accuracy Altitude
Mission Lifetime
Time spent in region
Latitude range
Latency
# Simultaneous data pts
Data Completeness
Pointing Accuracy
Pointing Control
(km... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
equatorial. Measure in hours per day.
Latency: The maximum elapsed time between the collection of data and the start of transmission downlink to
the communication network, measured in hours. This attribute does not incorporate delays to use.
Scientific Mission – Latency max and min for the AFRL model
Tech Demo Mission ... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
a desire to include launch systems and some
operational details (storage and parking modes and locations) in the trade study. This required a
rethinking of the attribute list, although it proved to be relatively minor. The updated attribute
list included a quantified response time, in hours, from 1 (best) to 2160, or t... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
ATOS vector contains no design vector
elements concerning the design of the vehicles themselves; the performance of the swarms are
only weakly dependent on the performance of the individual vehicles, so a nominal high-level
vehicle design is placed in the constants vector. BTOS has only the highest level of vehicle
con... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
For space vehicles, this might include vehicle types,
subsystem choices, fuel loads, technologies used. For space systems, this might include orbits,
operating and communications modes, ground and launch systems used, etc.
Like the attributes, choosing the design vector is something of an art. In general, however, it i... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
, and even the analysis, progress, design variables may prove irrelevant or non-
discriminating. As often, sensitivity studies or changes in user preferences elevate variables
consigned to the constants vector to design vector status. The enumeration of the design vector
will almost always change somewhat, as sensitive... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
in the constants vector.
Unlike the orbits, appropriate design variables used to describe the spacecraft are not readily
apparent from the attributes. In general, the computational and modeling resources available will
tend to reduce the scope of possible architectures. The X-TOS team decided to eliminate
concepts such... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
Single; 2 Series; 2
Parallel
Justification
Emphasis on low altitude in utility function, therefore
sample at a higher rate at low altitudes
Utility curve declines quite steeply between 150 and 350
km; will take a significant utility hit if spacecraft never
flies below 350
Covers the possible range of inclinations
The l... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
structure, thermal,
non-propulsion power, and control and communications systems), which were reduced to a rule-
of-thumb mass; the details of the propulsion system (Isp, mass, and power), which varied
between the various types of propulsion but were fixed for each type; and development and
launch costs, which were bui... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
opinions. They
are intended to help the process rather than provide solutions, so best-effort work here is
expected and acceptable.
The central matrix gives a visual summary of the complexity of the calculations that will be
necessary to compute the attributes given the design vector. A heavily-populated matrix tends t... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
mapping
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Attributes
Data Lifespan
Sample Altitude
Diversity of Latitudes
Time at Equator
Latency
Total
Cost
T... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
scenario
(how many vehicles are launched, when, into what orbits) affects most attributes very strongly.
The totals indicate that data lifespan is impacted by many of the design variables and may be the
most discriminating of the attributes. (In hindsight, this proved to be the case). Diversity of
latitudes, on the oth... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
Equipment capability is uniquely
determined by equipment mass. Response time is primarily determined by the choice of
propulsion system, with relatively weak interactions with the other design variables that were
ultimately ignored. The delta-V calculation will be the most difficult, depending on all of the
design vari... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
Cambridge, MA, 2002.
8 This section is modeled on, and has edited text from, Hugh L. McManus, Daniel E. Hastings,
and Joyce M. Warmkessel, “New Methods for Rapid Architecture Selection and Conceptual
Design,” Journal of Spacecraft and Rockets. < Vol and Number TBD)>
9 McManus, H. L., and Warmkessel, J. M., “Creating Ad... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
, T. E., “Understanding the
Orbital Transfer Vehicle Trade Space,” AIAA Paper 2003-6370, Sept. 2003.
16 Figures from McManus, H. L. and Schuman, T. E., “Understanding the Orbital Transfer
Vehicle Trade Space,” AIAA Paper 2003-6370, Sept. 2003.
17 Aguilar, J. A., and Dawdy, A., “Scope vs. Detail: The Teams of the Concep... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
Design Environment for Designing Space Instruments,”
Proceedings of the 9th Thermal and Fluids Analysis Workshop, Ohio Aerospace Institute and
NASA Lewis Research Center, Cleveland, Ohio, Sept. 1998.
25 Smith, P. L., Dawdy, A. D., Trafton, T. W., Novak, R. G., and Presley, S. P., "Concurrent
Design at Aerospace." Cross... | https://ocw.mit.edu/courses/16-892j-space-system-architecture-and-design-fall-2004/5c7b371feea1c1563d917c1858f58ec7_03010lec3framev5.pdf |
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