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Snapchat	adding stickers easier access audio video conferencing ability leave audio video notes ability share recent camera photos.implementation features meant allow users easily shift text audio video chat needed retaining equal level functionality.june snapchat added feature deleting sent message including audio video text read.feature introduced august allows users send musical gifs tunemojis.encryption january snapchat introduced use endtoend encryption application snaps pictures video according snapchat security engineer presenting january real world crypto conference.
Snapchat	january conference snapchat plans introduce endtoend encryption text messages group chats future.business multimedia demographics earliest days snapchats main demographic consisted generation z age group.app store age classification .researchers university washington seattle pacific university designed user survey help understand application used.researchers originally hypothesized due ephemeral nature snapchat messages use would predominantly privacysensitive content including much talked potential use sexual content sexting.
Snapchat	however appears snapchat used variety creative purposes necessarily privacyrelated all.study .respondents reported using snapchat primarily sexting although .admitted sent sexual content via snapchat point.findings suggest users seem utilize snapchat sensitive content.
Snapchat	rather primary use snapchat found comedic content stupid faces .respondents reporting use commonly.researchers also determined snapchat users use application types content willing send.found majority users willing send content classified sexting .respondents photos documents .
Snapchat	respondents messages containing legally questionable content .respondents content considered mean insulting .respondents.the study results also suggested snapchats success due security properties users found application fun.researchers found users seem wellaware .respondents recovering snaps possible majority users .
Snapchat	respondents report affect behavior use snapchat.many users .respondents found use arbitrary timeout length snaps regardless content type recipient.remaining respondents found adjust snaps timeout depending content recipient.reasons adjusting time length snaps included level trust relationship recipient time needed comprehend snap avoiding screenshots.
Snapchat	communication snapchat often seen represent new direction social media users craving inthemoment way sharing communicating via technology.less emphasis accumulation ongoing status involving presence permanent material snapchat put focus ephemeral nature fleeting encounters.building distinction launching mobilefirst company snapchat midst app revolution growing presence cellular communication make transition mobile way competing social media networks do.evan spiegel described snapchat primarily camera company.spiegel also dismissed past comparisons social media networks facebook twitter asked presidential race going remembered snapchat election although major candidates occasionally use app reach voters.nevertheless growing mobile app moved offer distinct publication media news content within discover channel well overall style presentation.
Snapchat	snapchat clear identifiable line drawn brand content userbased messaging sharing distinguishing popular app social media networks typically blended blurred different varieties content.monetization snapchats developing features embody deliberate strategy monetization.snapchat announced thenupcoming advertising efforts october acknowledged need revenue stream.company stated wanted evaluate deliver experience thats fun informative way ads used got creepy targeted.snapchats first paid advertisement form second movie trailer horror film ouija shown users october .in january snapchat began making shift focusing growth monetization.company launched discover feature allowed paid advertising presenting shortform content publishers.
Snapchat	initial launch partners included cnn comedy central espn food network among others.june snapchat announced would allow advertisers purchase sponsored geofilters snaps early customer offering mcdonalds paid branded geofilter covering restaurant locations united states.snapchat made push earn ad revenue live stories feature initially launching feature .ad placements sold within live story story pitched sponsor.live stories estimated reach average million viewers hour span.
Snapchat	campaigns september service entered partnership national football league present live stories selected games including sunday game marquee games monday night football thursday night football parties contributing content handling ad sales.internet trends report mary meeker highlighted significant growth vertical video viewing.vertical video ads like snapchats watched entirety nine times landscape video ads.gatorade came animated filter part super bowl ads .dunk lens gatorade received million views snapchat.in april nbc olympics announced reached deal snapchat allow stories summer olympics featured snapchat united states.
Snapchat	content would include behindthescenes discover channel curated buzzfeed company nbcuniversal funded stories featuring combination footage nbc athletes attendees.nbc sold advertising entered revenue sharing agreements.marked first time nbc allowed olympics footage featured thirdparty property.may part campaign promote xmen apocalypse th century fox paid entire array lenses replaced based characters xmen series films single day.july reported snapchat submitted patent application process using object recognition system deliver sponsored filters based objects seen camera view.
Snapchat	later year september snapchat released first hardware product called spectacles.evan spiegel ceo snap inc. called “a toy” saw upside freeing app smartphone cameras.in april digiday reported snapchat would launch selfservice manager advertising platform.feature launched following month alongside news snapchat mobile dashboard tracking ad campaigns rolled june select countries.also snapchat introduced snap store advertising tool lets companies using geostickers track whether users buy product visit store day period seeing relevant geosticker.november snapchat announced launch snap store sell bitmoji merchandise personalized avatars users friends.
Snapchat	items sale include shirts mugs shower curtains phone cases.development platform june snapchat announced new thirdparty development platform known snap kit suite components allows partners provide thirdparty integrations aspects service.login kit social login platform utilizes snapchat accounts.promoted privacyconscious competing equivalents services able receive users display name optionally bitmoji avatar subject day inactivity timeout preventing able collect personal information social graphs authorization.creative kit allows apps generate stickers overlay snapchat posts.
Snapchat	story kit used embed aggregate publicly posted stories example bandsintown using story kit aggregate stories posted musicians bitmoji kit allows bitmoji stickers integrated thirdparty apps.snap originals response industry competition streaming platforms netflix snapchat announced late would diversify content launching snap originals episodic content including scripted shows documentaries.in june snapchat announced creation firstever shoppable original show called drop focused exclusive streetwear collage celebrities designers.episode explored relationship designer celebrity collaborator.viewers would learn item sale came together well time day item would go sale.later day aforementioned time episode would updated content included swipe buy action.
Snapchat	premium accounts sexual content snapchat introduced new feature called snapcash spurred popularity among adult content creators.snapchat allows private premium accounts users monetize content.feature mostly used models monetize adult content.snapchat increasingly becoming integral part online porn industry.controversies december hack snapchat hacked december .gibson security australian security firm disclosed api security vulnerability company august made public source code exploit december .
Snapchat	december snapchat announced implemented mitigating features.nonetheless anonymous group hacked saying mitigating features presented minor obstacles.hackers revealed parts approximately .million snapchat usernames phone numbers website named snapchatdb.info sent statement popular technology blog techcrunch saying objective raise public awareness... and... put public pressure snapchat fix vulnerability.snapchat apologized week hack.
Snapchat	federal trade commission snapchat settled complaint made us federal trade commission ftc.government agency alleged company exaggerated public degree mobile app images photos could actually made disappear.terms agreement snapchat fined app service agreed claims policies monitored independent party period years.ftc concluded snapchat prohibited misrepresenting extent maintains privacy security confidentiality users information.following agreement snapchat updated privacy page state company cant guarantee messages deleted within specific timeframe.even snapchat deletes message data servers data may remain backup certain period time.
Snapchat	public blog post service warned youve ever tried recover lost data accidentally deleting drive maybe watched episode csi might know right forensic tools sometimes possible retrieve data deleted.windows app november snapchat announced crackdown thirdparty apps service users.users windows phone platform affected snapchat official client numerous thirdparty apps existed popularly one called snap.december microsoft forced remove snap thirdparty apps snapchat windows phone store snapchat however develop official app platform leaving users platform behind.petition users requesting official snapchat app reached signatures company still refused respond build app windows phone.
Snapchat	snapchat criticized later develop app microsofts universal windows platform uwp.lens incidents september yearold using snapchat feature called lens record speed driving mercedes c crashed mitsubishi outlander hampton georgia.mph kmh crash injured drivers.driver outlander spent five weeks intensive care treated severe traumatic brain injury.april outlander driver sued snapchat user snapchat alleging snapchat knew application used unlawful speed contests yet nothing prevent use negligent.in october similar collision driving mph kmh occurred tampa florida killed five people.
Snapchat	poor country remark according former snapchat employee anthony pompliano lawsuit filed snap inc. spiegel made statement snapchat rich people want expand poor countries like india spain.incident sparked twitter trend called uninstallsnapchat indian users uninstalled app caused backlash company terms low onestar ratings app google play store apples app store.snapchats shares fell .. response allegation snapchat called pomplianos claim ridiculous elaborated obviously snapchat everyone.it’s available worldwide download free.pompliano lawsuit january former employee anthony pompliano filed state lawsuit accusing snapchat doctoring growth metrics intention deceiving investors.
Snapchat	pompliano said ceo evan spiegel dismissive concerns pompliano fired shortly thereafter.judge dropped pompliano’s claims snapchat violated doddfrank consumer protection acts retaliation citing arbitration clause contract.however snap inc. faced blowback lack disclosure regarding contents lawsuit resulting plunging stock prices several classaction lawsuits federal investigations.snap map privacy concerns june release snap map feature broadcasts users location map met concerns privacy safety.feature optin delivers message asking user would like show position map reportedly explain ramifications including app updates users position map time app opened actively capturing snaps potentially assisting stalkers.
Snapchat	map zoomed feature detailed geographical information street addresses.daily telegraph reported police forces issued child safety warnings media publications wrote safety concerns also raised teenagers adults unaware features actual behavior.statement verge snapchat spokesperson said safety community important us want make sure snapchatters parents educators accurate information snap map works.users ability operate ghost mode select friends wish share location with.although increase advertising snapchat snapchat stated plan running ads snap map stories.rihanna controversy march advertisement containing poll rihanna posted stating would rather punch chris brown slap rihanna rihanna tweeted snapchat insensitive domestic violence victims urged fans delete snapchat.
Snapchat	body image concerns increased use body facial reshaping applications snapchat facetune identified potential cause body dysmorphic disorder.august researchers boston medical center wrote jama facial plastic surgery essay phenomenon called snapchat dysmorphia identified people request surgery look like edited version appear snapchat filters.snapchat employees abused data access spy users may revealed multiple snapchat employees used internal tool called snaplion originally designed gather data compliance law enforcement requests spy users.mozilla calls public disclosures related use a.i.citing vague broad language snapchats privacy policy mozilla issued september petition calling public disclosures related apps use facial emotion recognition technology.
Snapchat	reached comment scientific american representatives snapchat declined share public response.revenge porn lockdown inhibit spread covid france app emerged hub dissemination revenge porn underage girls.in woman north carolina sued snapchat well dating app tinder five men named attack claiming features app enabled alleged rapist friends hide evidence rape.particular suit alleges ways snapchat designed constructed marketed maintained womans assailants able send nonconsensual pornographic photographs videos little threat law enforcement verifying so.woman told court parent company snap inc. specifically purposely designed constructed maintained snapchat serve secretive nefarious communications platform encourages solicits facilitates creation dissemination illicit nonconsensual sexually explicit content...and allowed snapchat operate safehaven law enforcement.see also comparison crossplatform instant messaging clientstimeline social mediasobrr another mobile application deletes content specified timepurikura japanese photo sticker booths earlier used snapchatlike filtersyahoopicsartyuboyo appibeer references reading kosoff maya february .
Snapchat	dozen millennials explain theyre obsessed snapchat use it.business insider.axel springer se.retrieved april .external links official website
Private Disk	works creating virtual drive contents encrypted onthefly software use drive usual one.one private disks key selling points ease use achieved hiding complexity end user e.g.data wiping applied transparently encrypted image deleted.simplicity however reduce flexibility respects e.g.allows use aes encryption.although private disk uses nist certified implementation aes sha algorithms certification restricted single component private disk encryptionhash library used private disk complete system.feature highlights nistcertified implementation aesbit sha.
Building automation	private disk complies fips fips cbc mode secret ivs used encrypt sectors storage volumedisk firewall applicationlevel filter allows trusted programs access virtual driveability run directly removable drive requiring local installationoffers access encrypted data system even administrative privileges availableencrypted images accessed windows mobile windows ce handhelds achieved making encrypted container format compatible containers used secubox disk encryption software aiko solutionsfile wiping applied deleting encrypted imagepd file move file migration tool locate specified files system securely move encrypted diskcompatibility windows x windows nt operating systemsautorun autofinish automatically start program script virtual disk mounted dismountedencrypted backup encrypted imagepassword quality meterautomatic backup disks encryption keybuiltin password recovery toolcompatibility bit platformsexisting versionsthere multiple versions private disk provide different feature setprivate disk hard disk encryption software uses bit aes encryption highly configurable offers applicationlevel protection usb disk portability etc.private disk multifactor superset private disk providing functionality adding support biometric authentication well smartcard tokenbased authentication.private disk light free version uses aes comes restricted set features.private disk sdk software development kit used build custom application provides data encryption facilities.see also disk encryption softwarecomparison disk encryption software external links dekart company webpageinformation certified implementations cryptographic algorithmsprivate disk discussion forumrelease notes latest version referencesobjectives building automation improved occupant comfort efficient operation building systems reduction energy consumption reduced operating maintaining costs increased security historical performance documentation remote accesscontroloperation improved life cycle equipment related utilities.building automation example distributed control system – computer networking electronic devices designed monitor control systems building.bas core functionality keeps building climate within specified range provides light rooms based occupancy schedule absence overt switches contrary monitors performance device failures systems provides malfunction alarms building maintenance staff.bas reduce building energy maintenance costs compared noncontrolled building.commercial institutional industrial buildings built include bas.many older buildings retrofitted new bas typically financed energy insurance savings savings associated preemptive maintenance fault detection.a building controlled bas often referred intelligent building smart building residence smart home.commercial industrial buildings historically relied robust proven protocols like bacnet proprietary protocols like x used homes.
Building automation	recent ieee standards notably ieee .. ieee ieee .ieee .ieee .ac ieee .at consortia efforts like nvoy verifies ieee .compliance qivicon provided standardsbased foundation heterogeneous networking many devices many physical networks diverse purposes quality service failover guarantees appropriate support human health safety.accordingly commercial industrial military institutional users use systems differ home systems mostly scale.
Building automation	see home automation entry level systems nvoy .major proprietary vendors implement resist trend standards integration.almost multistory green buildings designed accommodate bas energy air water conservation characteristics.electrical device demand response typical function bas sophisticated ventilation humidity monitoring required tight insulated buildings.green buildings also use many lowpower dc devices possible.even passivhaus design intended consume net energy whatsoever typically require bas manage heat capture shading venting scheduling device use.
Building automation	automation system term building automation system loosely used refers electrical control system used control buildings heating ventilation air conditioning hvac system.modern bas also control indoor outdoor lighting well security fire alarms basically everything else electrical building.old hvac control systems v dc wired thermostats pneumatic controls form automation lack modern systems flexibility integration.buses protocols building automation networks consist primary secondary bus connect highlevel controllers generally specialized building automation may generic programmable logic controllers lowerlevel controllers inputoutput devices user interface also known human interface device.ashraes open protocol bacnet open protocol lontalk specify devices interoperate.
Building automation	modern systems use snmp track events building decades history snmpbased protocols computer networking world.physical connectivity devices historically provided dedicated optical fiber ethernet arcnet rs rs lowbandwidth special purpose wireless network.modern systems rely standardsbased multiprotocol heterogeneous networking specified ieee .standard verified nvoy auditing mark.accommodate typically ipbased networking make use existing wiring also integrate powerline networking ac circuits power ethernet lowpower dc circuits highbandwidth wireless networks lte ieee .n ieee .ac often integrate using buildingspecific wireless mesh open standard zigbee.proprietary hardware dominates controller market.company controllers specific applications.
Building automation	designed limited controls interoperability simple packaged roof top units hvac.software typically integrate well packages vendors.cooperation zigbeebacnetlontalk level only.current systems provide interoperability application level allowing users mixandmatch devices different manufacturers provide integration compatible building control systems.typically rely snmp long used purpose integrate diverse computer networking devices one coherent network.types inputs outputs sensors analog inputs used read variable measurement.
Building automation	examples temperature humidity pressure sensors could thermistor – – volt platinum resistance thermometer resistance temperature detector wireless sensors.a digital input indicates device off.examples digital inputs would door contact switch current switch air flow switch voltagefree relay contact dry contact.digital inputs could also pulse inputs counting pulses period time.example turbine flow meter transmitting flow data frequency pulses input.nonintrusive load monitoring software relying digital sensors algorithms discover appliance loads electrical magnetic characteristics circuit.however detecting event analog means.
Building automation	extremely costeffective operation useful identification detect startup transients line equipment faults etc.controls digital outputs control speed position device variable frequency drive ip current pneumatics transducer valve damper actuator.example hot water valve opening maintain setpoint.another example variable frequency drive ramping motor slowly avoid hard start.analog outputs used open close relays switches well drive load upon command.example would turn parking lot lights photocell indicates dark outside.
Building automation	another example would open valve allowing vdcac pass output powering valve.analog outputs could also pulse type outputs emitting frequency pulses given period time.example energy meter calculating kwh emitting frequency pulses accordingly.infrastructure controller controllers essentially small purposebuilt computers input output capabilities.controllers come range sizes capabilities control devices commonly found buildings control subnetworks controllers.inputs allow controller read temperature humidity pressure current flow air flow essential factors.
Building automation	outputs allow controller send command control signals slave devices parts system.inputs outputs either digital analog.digital outputs also sometimes called discrete depending manufacturer.controllers used building automation grouped three categories programmable logic controllers plcs systemnetwork controllers terminal unit controllers.however additional device also exist order integrate thirdparty systems e.g.standalone ac system central building automation system.terminal unit controllers usually suited control lighting andor simpler devices package rooftop unit heat pump vav box fan coil etc.
Building automation	installer typically selects one available preprogrammed personalities best suited device controlled create new control logic.occupancy occupancy one two operating modes building automation system.unoccupied morning warmup nighttime setback common modes.occupancy usually based time day schedules.occupancy mode bas aims provides comfortable climate adequate lighting often zonebased control users one side building different thermostat different system sub system users opposite side.a temperature sensor zone provides feedback controller deliver heating cooling needed.if enabled morning warmup mwu mode occurs prior occupancy.morning warmup bas tries bring building setpoint time occupancy.
Building automation	bas often factors outdoor conditions historical experience optimize mwu.also referred optimized start.an override manually initiated command bas.example many wallmounted temperature sensors pushbutton forces system occupancy mode set number minutes.present web interfaces allow users remotely initiate override bas.some buildings rely occupancy sensors activate lighting climate conditioning.given potential long lead times space becomes sufficiently cool warm climate conditioning often initiated directly occupancy sensor.
Building automation	lighting lighting turned dimmed building automation lighting control system based time day occupancy sensor photosensors timers.one typical example turn lights space halfhour since last motion sensed.photocell placed outside building sense darkness time day modulate lights outer offices parking lot.lighting also good candidate demand response many control systems providing ability dim turn lights take advantage dr incentives savings.in newer buildings lighting control based field bus digital addressable lighting interface dali.lamps dali ballasts fully dimmable.dali also detect lamp ballast failures dali luminaires signals failures.
Building automation	shading glazing shading glazing essential components building system affect occupants’ visual acoustical thermal comfort provide occupant view outdoor.automated shading glazing systems solutions controlling solar heat gains glare.refers use technology control external internal shading devices blinds shades glazing itself.system active rapid response various changing outdoor data solar wind changing interior environment temperature illuminance occupant demands.building shading glazing systems contribute thermal lighting improvement energy conservation comfort point view.
Building automation	dynamic shading dynamic shading devices allow control daylight solar energy enter built environment relation outdoor conditions daylighting demands solar positions.common products include venetian blinds roller shades louvers shutters.mostly installed interior side glazing system low maintenance cost also used exterior combination both.air handlers air handlers mix return outside air less temperaturehumidity conditioning needed.save money using less chilled heated water ahus use chilled hot water circuits.
Building automation	external air needed keep buildings air healthy.optimize energy efficiency maintaining healthy indoor air quality iaq demand control controlled ventilation dcv adjusts amount outside air based measured levels occupancy.analog digital temperature sensors may placed space room return supply air ducts sometimes external air.actuators placed hot chilled water valves outside air return air dampers.supply fan return applicable started stopped based either time day temperatures building pressures combination.constant volume airhandling units less efficient type airhandler constant volume air handling unit cav.
Building automation	fans cavs variablespeed controls.instead cavs open close dampers watersupply valves maintain temperatures buildings spaces.heat cool spaces opening closing chilled hot water valves feed internal heat exchangers.generally one cav serves several spaces.variable volume airhandling units efficient unit variable air volume vav airhandling unit vav.
Building automation	vavs supply pressurized air vav boxes usually one box per room area.vav air handler change pressure vav boxes changing speed fan blower variable frequency drive less efficiently moving inlet guide vanes fixedspeed fan.amount air determined needs spaces served vav boxes.each vav box supply air small space like office.box damper opened closed based much heating cooling required space.boxes open air required greater amount air supplied vav airhandling unit.some vav boxes also hot water valves internal heat exchanger.
Building automation	valves hot cold water opened closed based heat demand spaces supplying.heated vav boxes sometimes used perimeter interior zones cooling only.a minimum maximum cfm must set vav boxes assure adequate ventilation proper air balance.air handling unit ahu discharge air temperature control air handling units ahu roof top units rtu serve multiple zones vary discharge air temperature set point value automatically range °c °f.adjustment reduces cooling heating fan energy consumption.outside temperature °c °f zones low cooling loads raising supplyair temperature decreases use reheat zone level.
Building automation	vav hybrid systems another variation hybrid vav cav systems.system interior zones operate vav system.outer zones differ heating supplied heating fan central location usually heating coil fed building boiler.heated air ducted exterior dual duct mixing boxes dampers controlled zone thermostat calling either cooled heated air needed.central plant central plant needed supply airhandling units water.
Building automation	may supply chilled water system hot water system condenser water system well transformers auxiliary power unit emergency power.well managed often help other.example plants generate electric power periods peak demand using gas turbine use turbines hot exhaust heat water power absorptive chiller.chilled water system chilled water often used cool buildings air equipment.the chilled water system chillers pumps.analog temperature sensors measure chilled water supply return lines.
Building automation	chillers sequenced chill chilled water supply.a chiller refrigeration unit designed produce cool chilled water space cooling purposes.the chilled water circulated one cooling coils located air handling units fancoils induction units.chilled water distribution constrained foot separation limit applies dx systems thus chilled waterbased cooling systems typically used larger buildings.capacity control chilled water system usually achieved modulation water flow coils thus multiple coils may served single chiller without compromising control individual unit.chillers may operate either vapor compression principle absorption principle.vapor compression chillers may utilize reciprocating centrifugal screw rotary compressor configurations.reciprocating chillers commonly used capacities tons centrifugal chillers normally used provide higher capacities rotary screw chillers less commonly used rare.
Building automation	heat rejection chiller may way aircooled condenser cooling tower discussed below.vapor compression chillers may bundled aircooled condenser provide packaged chiller would installed outside building envelope.vapor compression chillers may also designed installed separate condensing unit normally chiller would installed enclosed central plant space.absorption chillers designed installed separate condensing unit.condenser water system cooling towers pumps used supply cool condenser water chillers.
Building automation	condenser water supply chillers constant variable speed drives commonly used cooling tower fans control temperature.proper cooling tower temperature assures proper refrigerant head pressure chiller.cooling tower set point used depends upon refrigerant used.analog temperature sensors measure condenser water supply return lines.hot water system hot water system supplies heat buildings airhandling unit vav box heating coils along domestic hot water heating coils calorifier.the hot water system boilers pumps.
Building automation	analog temperature sensors placed hot water supply return lines.type mixing valve usually used control heating water loop temperature.boilers pumps sequenced maintain supply.the installation integration variable frequency drives lower energy consumption buildings circulation pumps using before.variable frequency drive functions modulating frequency electricity provided motor powers.us electrical grid uses frequency hertz cycles per second.
Building automation	variable frequency drives able decrease output energy consumption motors lowering frequency electricity provided motor however relationship motor output energy consumption linear one.variable frequency drive provides electricity motor hertz output motor hertz divided hertz ..energy consumption motor running hertz instead something like relationship motor output energy consumption linear.exact ratios motor output hertz provided motor effectively thing actual energy consumption variable frequency drive motor combination depend efficiency variable frequency drive.
Building automation	example variable frequency drive needs power communicate building automation system run cooling fan etc.motor always ran variable frequency drive installed cost operation electricity consumption would actually go new variable frequency drive installed.amount energy variable frequency drives consume nominal hardly worth consideration calculating savings however need noted vfds consume energy themselves.variable frequency drives rarely ever run spend time output range pumps completely shut needed variable frequency drives reduced energy consumption pumps around using before.alarms security modern building automation systems alarm capabilities.
Building automation	little good detect potentially hazardous costly situation one solve problem notified.notification computer email text message pager cellular phone voice call audible alarm these.insurance liability purposes systems keep logs notified how.alarms may immediately notify someone notify alarms build threshold seriousness urgency.sites several buildings momentary power failures cause hundreds thousands alarms equipment shut – suppressed recognized symptoms larger failure.sites programmed critical alarms automatically resent varying intervals.
Building automation	example repeating critical alarm uninterruptible power supply bypass might resound minutes minutes every hours thereafter alarms resolved.common temperature alarms space supply air chilled water supply hot water supply.pressure humidity biological chemical sensors determine ventilation systems failed mechanically become infected contaminants affect human health.differential pressure switches placed filter determine dirty otherwise performing.status alarms common.mechanical device like pump requested start status input indicates indicate mechanical failure.worse electrical fault could represent fire shock hazard.some valve actuators end switches indicate valve opened not.carbon monoxide carbon dioxide sensors tell concentration air high either due fire ventilation problems garages near roads.refrigerant sensors used indicate possible refrigerant leak.current sensors used detect low current conditions caused slipping fan belts clogging strainers pumps problems.security systems interlocked building automation system.occupancy sensors present also used burglar alarms.security systems often deliberately sabotaged least detectors cameras battery backup wireless connectivity ability trigger alarms disconnected.
Building automation	modern systems typically use poweroverethernet operate pantiltzoom camera devices – watts capable charging batteries keeps wireless networks free genuinely wireless applications backup communication outage.fire alarm panels related smoke alarm systems usually hardwired override building automation.example smoke alarm activated outside air dampers close prevent air coming building exhaust system isolate blaze.similarly electrical fault detection systems turn entire circuits regardless number alarms triggers persons distresses.fossil fuel combustion devices also tend overrides natural gas feed lines turn slow pressure drops detected indicating leak excess methane detected buildings air supply.good bas aware overrides recognize complex failure conditions.send excessive alerts waste precious backup power trying turn back devices safety overrides turned off.
Building automation	poor bas almost definition sends one alarm every alert recognize manual fire electric fuel safety override.accordingly good bas often built safety fire systems.information security growing spectrum capabilities connections internet things building automation systems repeatedly reported vulnerable allowing hackers cybercriminals attack components.buildings exploited hackers measure change environment sensors allow surveillance e.g.monitoring movements employees habits inhabitants actuators allow perform actions buildings e.g.
Building automation	opening doors windows intruders.several vendors committees started improve security features products standards including knx zigbee bacnet see recent standards standard drafts.however researchers report several open problems building automation security.room automation room automation subset building automation similar purpose consolidation one systems centralized control though case one room.the common example room automation corporate boardroom presentation suites lecture halls operation large number devices define room function videoconferencing equipment video projectors lighting control systems public address systems etc.would make manual operation room complex.
Building automation	common room automation systems employ touchscreen primary way controlling operation.see also control engineeringdigital homeindex home automation articlessmart environmenttesting adjusting balancing protocols industry standards wirebacnetbluetoothdalidynetenoceaneubacknxlontalkmidacopcopenthermopenwebnetvscpzigbeezwave references external links media related building automation wikimedia commonsvbuilding automation provides learning resources professionals areaobjectives building automation improved occupant comfort efficient operation building systems reduction energy consumption reduced operating maintaining costs increased security historical performance documentation remote accesscontroloperation improved life cycle equipment related utilities.building automation example distributed control system – computer networking electronic devices designed monitor control systems building.bas core functionality keeps building climate within specified range provides light rooms based occupancy schedule absence overt switches contrary monitors performance device failures systems provides malfunction alarms building maintenance staff.bas reduce building energy maintenance costs compared noncontrolled building.commercial institutional industrial buildings built include bas.many older buildings retrofitted new bas typically financed energy insurance savings savings associated preemptive maintenance fault detection.a building controlled bas often referred intelligent building smart building residence smart home.commercial industrial buildings historically relied robust proven protocols like bacnet proprietary protocols like x used homes.
Building automation	recent ieee standards notably ieee .. ieee ieee .ieee .ieee .ac ieee .at consortia efforts like nvoy verifies ieee .compliance qivicon provided standardsbased foundation heterogeneous networking many devices many physical networks diverse purposes quality service failover guarantees appropriate support human health safety.accordingly commercial industrial military institutional users use systems differ home systems mostly scale.
Building automation	see home automation entry level systems nvoy .major proprietary vendors implement resist trend standards integration.almost multistory green buildings designed accommodate bas energy air water conservation characteristics.electrical device demand response typical function bas sophisticated ventilation humidity monitoring required tight insulated buildings.green buildings also use many lowpower dc devices possible.even passivhaus design intended consume net energy whatsoever typically require bas manage heat capture shading venting scheduling device use.
Building automation	automation system term building automation system loosely used refers electrical control system used control buildings heating ventilation air conditioning hvac system.modern bas also control indoor outdoor lighting well security fire alarms basically everything else electrical building.old hvac control systems v dc wired thermostats pneumatic controls form automation lack modern systems flexibility integration.buses protocols building automation networks consist primary secondary bus connect highlevel controllers generally specialized building automation may generic programmable logic controllers lowerlevel controllers inputoutput devices user interface also known human interface device.ashraes open protocol bacnet open protocol lontalk specify devices interoperate.
Building automation	modern systems use snmp track events building decades history snmpbased protocols computer networking world.physical connectivity devices historically provided dedicated optical fiber ethernet arcnet rs rs lowbandwidth special purpose wireless network.modern systems rely standardsbased multiprotocol heterogeneous networking specified ieee .standard verified nvoy auditing mark.accommodate typically ipbased networking make use existing wiring also integrate powerline networking ac circuits power ethernet lowpower dc circuits highbandwidth wireless networks lte ieee .n ieee .ac often integrate using buildingspecific wireless mesh open standard zigbee.proprietary hardware dominates controller market.company controllers specific applications.
Building automation	designed limited controls interoperability simple packaged roof top units hvac.software typically integrate well packages vendors.cooperation zigbeebacnetlontalk level only.current systems provide interoperability application level allowing users mixandmatch devices different manufacturers provide integration compatible building control systems.typically rely snmp long used purpose integrate diverse computer networking devices one coherent network.types inputs outputs sensors analog inputs used read variable measurement.
Building automation	examples temperature humidity pressure sensors could thermistor – – volt platinum resistance thermometer resistance temperature detector wireless sensors.a digital input indicates device off.examples digital inputs would door contact switch current switch air flow switch voltagefree relay contact dry contact.digital inputs could also pulse inputs counting pulses period time.example turbine flow meter transmitting flow data frequency pulses input.nonintrusive load monitoring software relying digital sensors algorithms discover appliance loads electrical magnetic characteristics circuit.however detecting event analog means.
Building automation	extremely costeffective operation useful identification detect startup transients line equipment faults etc.controls digital outputs control speed position device variable frequency drive ip current pneumatics transducer valve damper actuator.example hot water valve opening maintain setpoint.another example variable frequency drive ramping motor slowly avoid hard start.analog outputs used open close relays switches well drive load upon command.example would turn parking lot lights photocell indicates dark outside.
Building automation	another example would open valve allowing vdcac pass output powering valve.analog outputs could also pulse type outputs emitting frequency pulses given period time.example energy meter calculating kwh emitting frequency pulses accordingly.infrastructure controller controllers essentially small purposebuilt computers input output capabilities.controllers come range sizes capabilities control devices commonly found buildings control subnetworks controllers.inputs allow controller read temperature humidity pressure current flow air flow essential factors.
Building automation	outputs allow controller send command control signals slave devices parts system.inputs outputs either digital analog.digital outputs also sometimes called discrete depending manufacturer.controllers used building automation grouped three categories programmable logic controllers plcs systemnetwork controllers terminal unit controllers.however additional device also exist order integrate thirdparty systems e.g.standalone ac system central building automation system.terminal unit controllers usually suited control lighting andor simpler devices package rooftop unit heat pump vav box fan coil etc.
Building automation	installer typically selects one available preprogrammed personalities best suited device controlled create new control logic.occupancy occupancy one two operating modes building automation system.unoccupied morning warmup nighttime setback common modes.occupancy usually based time day schedules.occupancy mode bas aims provides comfortable climate adequate lighting often zonebased control users one side building different thermostat different system sub system users opposite side.a temperature sensor zone provides feedback controller deliver heating cooling needed.if enabled morning warmup mwu mode occurs prior occupancy.morning warmup bas tries bring building setpoint time occupancy.
Building automation	bas often factors outdoor conditions historical experience optimize mwu.also referred optimized start.an override manually initiated command bas.example many wallmounted temperature sensors pushbutton forces system occupancy mode set number minutes.present web interfaces allow users remotely initiate override bas.some buildings rely occupancy sensors activate lighting climate conditioning.given potential long lead times space becomes sufficiently cool warm climate conditioning often initiated directly occupancy sensor.
Building automation	lighting lighting turned dimmed building automation lighting control system based time day occupancy sensor photosensors timers.one typical example turn lights space halfhour since last motion sensed.photocell placed outside building sense darkness time day modulate lights outer offices parking lot.lighting also good candidate demand response many control systems providing ability dim turn lights take advantage dr incentives savings.in newer buildings lighting control based field bus digital addressable lighting interface dali.lamps dali ballasts fully dimmable.dali also detect lamp ballast failures dali luminaires signals failures.
Building automation	shading glazing shading glazing essential components building system affect occupants’ visual acoustical thermal comfort provide occupant view outdoor.automated shading glazing systems solutions controlling solar heat gains glare.refers use technology control external internal shading devices blinds shades glazing itself.system active rapid response various changing outdoor data solar wind changing interior environment temperature illuminance occupant demands.building shading glazing systems contribute thermal lighting improvement energy conservation comfort point view.
Building automation	dynamic shading dynamic shading devices allow control daylight solar energy enter built environment relation outdoor conditions daylighting demands solar positions.common products include venetian blinds roller shades louvers shutters.mostly installed interior side glazing system low maintenance cost also used exterior combination both.air handlers air handlers mix return outside air less temperaturehumidity conditioning needed.save money using less chilled heated water ahus use chilled hot water circuits.
Building automation	external air needed keep buildings air healthy.optimize energy efficiency maintaining healthy indoor air quality iaq demand control controlled ventilation dcv adjusts amount outside air based measured levels occupancy.analog digital temperature sensors may placed space room return supply air ducts sometimes external air.actuators placed hot chilled water valves outside air return air dampers.supply fan return applicable started stopped based either time day temperatures building pressures combination.constant volume airhandling units less efficient type airhandler constant volume air handling unit cav.
Building automation	fans cavs variablespeed controls.instead cavs open close dampers watersupply valves maintain temperatures buildings spaces.heat cool spaces opening closing chilled hot water valves feed internal heat exchangers.generally one cav serves several spaces.variable volume airhandling units efficient unit variable air volume vav airhandling unit vav.
Building automation	vavs supply pressurized air vav boxes usually one box per room area.vav air handler change pressure vav boxes changing speed fan blower variable frequency drive less efficiently moving inlet guide vanes fixedspeed fan.amount air determined needs spaces served vav boxes.each vav box supply air small space like office.box damper opened closed based much heating cooling required space.boxes open air required greater amount air supplied vav airhandling unit.some vav boxes also hot water valves internal heat exchanger.
Building automation	valves hot cold water opened closed based heat demand spaces supplying.heated vav boxes sometimes used perimeter interior zones cooling only.a minimum maximum cfm must set vav boxes assure adequate ventilation proper air balance.air handling unit ahu discharge air temperature control air handling units ahu roof top units rtu serve multiple zones vary discharge air temperature set point value automatically range °c °f.adjustment reduces cooling heating fan energy consumption.outside temperature °c °f zones low cooling loads raising supplyair temperature decreases use reheat zone level.
Building automation	vav hybrid systems another variation hybrid vav cav systems.system interior zones operate vav system.outer zones differ heating supplied heating fan central location usually heating coil fed building boiler.heated air ducted exterior dual duct mixing boxes dampers controlled zone thermostat calling either cooled heated air needed.central plant central plant needed supply airhandling units water.
Building automation	may supply chilled water system hot water system condenser water system well transformers auxiliary power unit emergency power.well managed often help other.example plants generate electric power periods peak demand using gas turbine use turbines hot exhaust heat water power absorptive chiller.chilled water system chilled water often used cool buildings air equipment.the chilled water system chillers pumps.analog temperature sensors measure chilled water supply return lines.
Building automation	chillers sequenced chill chilled water supply.a chiller refrigeration unit designed produce cool chilled water space cooling purposes.the chilled water circulated one cooling coils located air handling units fancoils induction units.chilled water distribution constrained foot separation limit applies dx systems thus chilled waterbased cooling systems typically used larger buildings.capacity control chilled water system usually achieved modulation water flow coils thus multiple coils may served single chiller without compromising control individual unit.chillers may operate either vapor compression principle absorption principle.vapor compression chillers may utilize reciprocating centrifugal screw rotary compressor configurations.reciprocating chillers commonly used capacities tons centrifugal chillers normally used provide higher capacities rotary screw chillers less commonly used rare.
Building automation	heat rejection chiller may way aircooled condenser cooling tower discussed below.vapor compression chillers may bundled aircooled condenser provide packaged chiller would installed outside building envelope.vapor compression chillers may also designed installed separate condensing unit normally chiller would installed enclosed central plant space.absorption chillers designed installed separate condensing unit.condenser water system cooling towers pumps used supply cool condenser water chillers.
Building automation	condenser water supply chillers constant variable speed drives commonly used cooling tower fans control temperature.proper cooling tower temperature assures proper refrigerant head pressure chiller.cooling tower set point used depends upon refrigerant used.analog temperature sensors measure condenser water supply return lines.hot water system hot water system supplies heat buildings airhandling unit vav box heating coils along domestic hot water heating coils calorifier.the hot water system boilers pumps.
Building automation	analog temperature sensors placed hot water supply return lines.type mixing valve usually used control heating water loop temperature.boilers pumps sequenced maintain supply.the installation integration variable frequency drives lower energy consumption buildings circulation pumps using before.variable frequency drive functions modulating frequency electricity provided motor powers.us electrical grid uses frequency hertz cycles per second.
Building automation	variable frequency drives able decrease output energy consumption motors lowering frequency electricity provided motor however relationship motor output energy consumption linear one.variable frequency drive provides electricity motor hertz output motor hertz divided hertz ..energy consumption motor running hertz instead something like relationship motor output energy consumption linear.exact ratios motor output hertz provided motor effectively thing actual energy consumption variable frequency drive motor combination depend efficiency variable frequency drive.
Building automation	example variable frequency drive needs power communicate building automation system run cooling fan etc.motor always ran variable frequency drive installed cost operation electricity consumption would actually go new variable frequency drive installed.amount energy variable frequency drives consume nominal hardly worth consideration calculating savings however need noted vfds consume energy themselves.variable frequency drives rarely ever run spend time output range pumps completely shut needed variable frequency drives reduced energy consumption pumps around using before.alarms security modern building automation systems alarm capabilities.
Building automation	little good detect potentially hazardous costly situation one solve problem notified.notification computer email text message pager cellular phone voice call audible alarm these.insurance liability purposes systems keep logs notified how.alarms may immediately notify someone notify alarms build threshold seriousness urgency.sites several buildings momentary power failures cause hundreds thousands alarms equipment shut – suppressed recognized symptoms larger failure.sites programmed critical alarms automatically resent varying intervals.
Building automation	example repeating critical alarm uninterruptible power supply bypass might resound minutes minutes every hours thereafter alarms resolved.common temperature alarms space supply air chilled water supply hot water supply.pressure humidity biological chemical sensors determine ventilation systems failed mechanically become infected contaminants affect human health.differential pressure switches placed filter determine dirty otherwise performing.status alarms common.mechanical device like pump requested start status input indicates indicate mechanical failure.worse electrical fault could represent fire shock hazard.some valve actuators end switches indicate valve opened not.carbon monoxide carbon dioxide sensors tell concentration air high either due fire ventilation problems garages near roads.refrigerant sensors used indicate possible refrigerant leak.current sensors used detect low current conditions caused slipping fan belts clogging strainers pumps problems.security systems interlocked building automation system.occupancy sensors present also used burglar alarms.security systems often deliberately sabotaged least detectors cameras battery backup wireless connectivity ability trigger alarms disconnected.
Building automation	modern systems typically use poweroverethernet operate pantiltzoom camera devices – watts capable charging batteries keeps wireless networks free genuinely wireless applications backup communication outage.fire alarm panels related smoke alarm systems usually hardwired override building automation.example smoke alarm activated outside air dampers close prevent air coming building exhaust system isolate blaze.similarly electrical fault detection systems turn entire circuits regardless number alarms triggers persons distresses.fossil fuel combustion devices also tend overrides natural gas feed lines turn slow pressure drops detected indicating leak excess methane detected buildings air supply.good bas aware overrides recognize complex failure conditions.send excessive alerts waste precious backup power trying turn back devices safety overrides turned off.
Building automation	poor bas almost definition sends one alarm every alert recognize manual fire electric fuel safety override.accordingly good bas often built safety fire systems.information security growing spectrum capabilities connections internet things building automation systems repeatedly reported vulnerable allowing hackers cybercriminals attack components.buildings exploited hackers measure change environment sensors allow surveillance e.g.monitoring movements employees habits inhabitants actuators allow perform actions buildings e.g.
Building automation	opening doors windows intruders.several vendors committees started improve security features products standards including knx zigbee bacnet see recent standards standard drafts.however researchers report several open problems building automation security.room automation room automation subset building automation similar purpose consolidation one systems centralized control though case one room.the common example room automation corporate boardroom presentation suites lecture halls operation large number devices define room function videoconferencing equipment video projectors lighting control systems public address systems etc.would make manual operation room complex.
TCP offload engine	common room automation systems employ touchscreen primary way controlling operation.see also control engineeringdigital homeindex home automation articlessmart environmenttesting adjusting balancing protocols industry standards wirebacnetbluetoothdalidynetenoceaneubacknxlontalkmidacopcopenthermopenwebnetvscpzigbeezwave references external links media related building automation wikimedia commonsvbuilding automation provides learning resources professionals areaprimarily used highspeed network interfaces gigabit ethernet gigabit ethernet processing overhead network stack becomes significant.toes often used way reduce overhead associated internet protocol ip storage protocols iscsi network file system nfs.purpose originally tcp designed unreliable low speed networks early dialup modems growth internet terms backbone transmission speeds using optical carrier gigabit ethernet gigabit ethernet links faster reliable access mechanisms dsl cable modems frequently used data centers desktop pc environments speeds gigabit per second.speeds tcp software implementations host systems require significant computing power.early fullduplex gigabit tcp communication could consume .ghz pentium processor resulting small processing resources left applications run system.tcp connectionoriented protocol adds complexity processing overhead.
TCP offload engine	aspects includeconnection establishment using way handshake synchronize synchronizeacknowledge acknowledge.acknowledgment packets received far end adding message flow endpoints thus protocol load.checksum sequence number calculations burden general purpose cpu perform.sliding window calculations packet acknowledgement congestion control.connection termination.moving functions dedicated hardware tcp offload engine frees systems main cpu tasks.consumer network interface cards support toe.freedup cpu cycles generally accepted rule thumb hertz cpu processing required send receive bits tcpip.example gbits mbs network traffic requires ghz cpu processing.implies entire cores .
TCP offload engine	ghz multicore processor required handle tcpip processing associated gbits tcpip traffic.since ethernet ge example bidirectional possible send receive gbits aggregate throughput gbits.using hzbits rule equates eight .ghz cores.many cpu cycles used tcpip processing freedup tcpip offload may used cpu usually server cpu perform tasks file system processing file server indexing backup media server.words server tcpip offload server work server without tcpip offload nics.
TCP offload engine	reduction pci traffic addition protocol overhead toe address also address architectural issues affect large percentage host based server pc endpoints.many older end point hosts pci bus based provides standard interface addition certain peripherals network interfaces servers pcs.pci inefficient transferring small bursts data main memory across pci bus network interface ics efficiency improves data burst size increases.within tcp protocol large number small packets created e.g.acknowledgements typically generated host cpu transmitted across pci bus network physical interface impacts host computer io throughput.a toe solution located network interface located side pci bus cpu host address io efficiency issue data sent across tcp connection sent toe cpu across pci bus using large data burst sizes none smaller tcp packets traverse pci bus.history one first patents technology udp offload issued auspex systems early .auspex founder larry boucher number auspex engineers went found alacritech idea extending concept network stack offload tcp implementing custom silicon.
TCP offload engine	introduced first parallelstack full offload network card early companys slic session layer interface card predecessor current toe offerings.alacritech holds number patents area tcpip offload.by emergence tcpbased storage iscsi spurred interest said least dozen newcomers founded toward end dotcom bubble chasing opportunity merchant semiconductor accelerators storage protocols applications vying half dozen entrenched vendors inhouse asic designs.in microsoft licensed alacritechs patent base along alacritech created partial tcp offload architecture become known tcp chimney offload.tcp chimney offload centers alacritech communication block passing patent.time broadcom also obtained license build tcp chimney offload chips.types tcpip offload instead replacing tcp stack toe entirely alternative techniques offload operations cooperation operating systems tcp stack.
TCP offload engine	tcp checksum offload large segment offload supported majority todays ethernet nics.newer techniques like large receive offload tcp acknowledgment offload already implemented highend ethernet hardware effective even implemented purely software.parallelstack full offload parallelstack full offload gets name concept two parallel tcpip stacks.first main host stack included host os.second parallel stack connected application layer transport layer tcp using vampire tap.
TCP offload engine	vampire tap intercepts tcp connection requests applications responsible tcp connection management well tcp data transfer.many criticisms following section relate type tcp offload.hba full offload hba host bus adapter full offload found iscsi host adapters present disk controllers host system connecting via tcpip iscsi storage device.type tcp offload offloads tcpip processing also offloads iscsi initiator function.hba appears host disk controller used iscsi devices appropriate general tcpip offload.
TCP offload engine	tcp chimney partial offload tcp chimney offload addresses major security criticism parallelstack full offload.partial offload main system stack controls connections host.connection established local host usually server foreign host usually client connection state passed tcp offload engine.heavy lifting data transmit receive handled offload device.almost tcp offload engines use type tcpip hardware implementation perform data transfer without host cpu intervention.
TCP offload engine	connection closed connection state returned offload engine main system stack.maintaining control tcp connections allows main system stack implement control connection security.large receive offload large receive offload lro technique increasing inbound throughput highbandwidth network connections reducing central processing unit cpu overhead.works aggregating multiple incoming packets single stream larger buffer passed higher networking stack thus reducing number packets processed.linux implementations generally use lro conjunction new api napi also reduce number interrupts.according benchmarks even implementing technique entirely software increase network performance significantly.
TCP offload engine	april linux kernel supports lro tcp software only.freebsd supports lro hardware adapters support it.lro operate machines acting routers breaks endtoend principle significantly impact performance.generic receive offload generic receive offload gro implements generalised lro software isnt restricted tcpipv issues created lro.large send offload computer networking large send offload lso technique increasing egress throughput highbandwidth network connections reducing cpu overhead.works passing multipacket buffer network interface card nic.

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