1,904 research outputs found
Evaluation of Variability Concepts for Simulink in the Automotive Domain
Modeling variability in Matlab/Simulink becomes more and more important. We
took the two variability modeling concepts already included in Matlab/Simulink
and our own one and evaluated them to find out which one is suited best for
modeling variability in the automotive domain. We conducted a controlled
experiment with developers at Volkswagen AG to decide which concept is
preferred by developers and if their preference aligns with measurable
performance factors. We found out that all existing concepts are viable
approaches and that the delta approach is both the preferred concept as well as
the objectively most efficient one, which makes Delta-Simulink a good solution
to model variability in the automotive domain.Comment: 10 pages, 7 figures, 6 tables, Proceedings of 48th Hawaii
International Conference on System Sciences (HICSS), pp. 5373-5382, Kauai,
Hawaii, USA, IEEE Computer Society, 201
After zero tolerance : the benefit of legal graffiti
Det hĂ€r Ă€r ett examensarbete pĂ„ 30 hp utfört 2012 pĂ„ vid institutionen för stad och land pĂ„ SLU i Ultuna. Bakgrunden Ă€r att Stockholm under flera Ă„rs tid har haft en vĂ€ldigt repressiv instĂ€llning gentemot fenomenet graffiti, det brukar kallas för nolltoleransen. Stadens styrande antog 2007 en skĂ€rpt klotterpolicy i vilken det fastslĂ„s att âstaden inte ska medverka till eller stödja verksamheter eller evenemang som inte klart tar avstĂ„nd frĂ„n klotter, olaglig graffiti och liknande skadegörelse. Staden skall heller inte medverka till verksamheter som pĂ„ nĂ„got sĂ€tt kan vĂ€cka intresse för och leda till klotter, olaglig graffiti eller liknande skadegörelse.â Policyn och i synnerhet formuleringen ovan har fĂ„tt utstĂ„ mycket kritik, efter att staden lagt sig i diverse kulturarrangemang med graffiti som tema. Att totalförbjuda möjligheter för staden att bemöta intresset för graffiti Ă€r dock inte det enda beprövade tillvĂ€gagĂ„ngssĂ€ttet för att minska den skadegörelseproblematik som graffitin medför. I Brottsförebyggande rĂ„dets skrift Klotterförebyggande Ă„tgĂ€rder (Hollari, 2005) redogörs för en rad exempel pĂ„ hur andra stĂ€der pĂ„ olika sĂ€tt bemött problemen, dĂ€r ofta lagliga möjligheter för graffitimĂ„leri Ă€r en av ingredienserna. SĂ„dana möjligheter, som vid en första anblick verkar vara pragmatiskt, Ă€r som en konsekvens av klotterpolicyn förstĂ„s otĂ€nkbar i Stockholm. Anledningen Ă€r att det frĂ„n stadens sida menas att lagliga graffitimöjligheter leder till mer mer olaglig graffiti, ett pĂ„stĂ„ende som till en början framfördes som fakta (Svt, 2010) men senare som en Ă„sikt, som nolltoleransföresprĂ„kare tror pĂ„ (Riksteatern, 2011). Debatten kring nolltoleransen handlar ofta om detta pĂ„stĂ„ende Ă€r sant eller ej, och om nolltoleransen i sin godtycklighet inkrĂ€ktar pĂ„ yttrandefriheten, och verkar som censur mot en kulturyttring.
Den hÀr uppsatsen handlar om lagliga graffitivÀggar, dock inte ur de tidigare nÀmnda synvinklarna. Syftet Àr att visa vad laglig graffiti kan ha för övriga effekter pÄ de platser dÀr det kan tÀnkas möjligt. Klotterpolicyns mÄlbeskrivning har varit utgÄngspunkten för detta. Vad som efterstrÀvas enligt denna Àr:
âStockholm ska vara en trygg, sĂ€ker, ren och vacker stad som vi Ă€r stolta över och dĂ€r stadsmiljön inbjuder till samvaro mellan mĂ€nniskor.â (Stockholms stad, 2007)
Min tes Àr att en laglig graffitivÀgg precis som andra funktioner i staden attraherar mÀnniskor, och kan verka i den riktning klotterpolicyn och sannolikt samtliga stadens invÄnare önskar.
Klotterpolicyns mĂ„lbeskrivning har del för del analyserats för att problematisera och erbjuda en djupare förstĂ„else av de begrepp den innehĂ„ller. Under rubriken trygg ges en bakgrund, och idĂ©n att graffiti skapar otrygghet ifrĂ„gasĂ€tts. Slutsatsen Ă€r mer eller mindre att nolltoleransen utmĂ„lat graffitimĂ„lare som âfarligaâ mĂ€nniskor och att aktiviteten graffitimĂ„leri nĂ„got som uteslutande sker i det fördolda vilket ger allmĂ€nheten fĂ„ möjligheter att möta konstnĂ€rerna. Fenomenet blir nĂ„got frĂ€mmande vilket Ă€r en grogrund för otrygghet. BetrĂ€ffande sĂ€ker menar jag att en laglig graffitivĂ€gg skulle befolka en plats, vilket med stöd frĂ„n Jane Jacobs (1962) Ă€r positivt ur sĂ€kerhetssynpunkt. Vacker Ă€r ett relativt begrepp och jag menar att staden Ă€r en kompromiss i det avseendet att vi fĂ„r leva med de utryck den innehĂ„ller. Som enskild invĂ„nare har vi fĂ„ möjligheter att pĂ„verka stadsbilden. Graffiti har sitt ursprung i det offentliga och dĂ€ri ligger dess styrka och potential. Laglig graffiti skulle kunna vara en av annars mycket fĂ„ möjligheter för allmĂ€nheten att bidra och sĂ€tta sitt avtryck i stadsrummet. En konsekvens av nolltoleranspolitiken Ă€r ocksĂ„ att gemene man blir mindre exponerad för mer utarbetad graffiti som tar lĂ„ng tid att utföra. AllmĂ€nheten fĂ„r i större utstrĂ€ckning istĂ€llet uppleva snabbt utförd graffiti, det som i mĂ„ngas Ă„sikt definieras som klotter. Adjektivet ren Ă€r ocksĂ„ det en tolkningsfrĂ„ga, mitt resonemang kring detta bygger mycket pĂ„ geografen David Harveys (2008) idĂ©er. Det Ă€r frĂ€mst ur perspektivet av Stockholm som en produkt som begreppet lĂ„tit sig definieras. En stad som marknadsförs som ren och hur marknaden ser pĂ„ det begreppet behöver dock inte alltid vara förenliga med invĂ„narnas önskemĂ„l och behov. BetrĂ€ffande stolthet och laglig graffiti sĂ€tter jag det i relation till stadens Kulturvision 2030, dĂ„ graffiti i mina ögon frĂ€mst Ă€r konstnĂ€rlig verksamhet och dĂ€rmed en kulturyttring. Kultur Ă€r mĂ€nniskans uttryck och kring detta kĂ€nner vi stolthet. Kulturvisionen har ambitiösa och fina mĂ„l men graffiti kan inte bidra till dessa dĂ„ klotterpolicyn inte Ă€r kompatibel med denna. En laglig graffitivĂ€gg skulle som sagt locka personer som mĂ„lar pĂ„ den, och mĂ€nsklig aktivitet har enligt Jan Gehl (2006) en stark attraktion, för att inte sĂ€ga den starkaste, pĂ„ andra mĂ€nniskor. Med detta argument och att lagliga möjligheter för graffiti ger ett alternativ till olagligt mĂ„leri, vilket drastiskt kan skada mĂ€nniskors framtidsutsikter, vill jag hĂ€vda att lagliga graffitivĂ€ggar ökar samvaron mellan mĂ€nniskor.
ArbetssÀttet har varit sÄdant att jag utgÄtt frÄn Jan Gehls (2006) kategorisering av platser i lÄg respektive hög kvalitet, dÀr mycket frivillig aktivitet kÀnnetecknar den senare. Genom sociala nÀtverk pÄ internet har jag frÄn graffitimÄlare sjÀlva fÄtt tips pÄ platser dÀr laglig graffiti enligt dem Àr önskvÀrt. DÀrefter har jag valt ut tvÄ platser utifrÄn tidigare nÀmnda kriterier och min bedömning av dess lÀmplighet som lagliga graffitivÀggar. Valet föll pÄ Tjurbergsparken vilken representerar en högkvalitativ plats och trottoaren utmed Zinkensdamms IP en plats av lÄg kvalitet, bÄda pÄ Södermalm i Stockholm. För att fÄ en djupare förstÄelse för hur dessa platser fungerar har jag valt att göra en analysmetod kallad experiential landscape. Kevin Thwaites och Ian Simkins (2007) utvecklade denna metod vilken har som utgÄngspunkt att det Àr relationen mellan mÀnniskan och rummet som skapar platsen, och analysmetoden syftar till att kartera mÀnniskans upplevelse och kÀnslomÀssiga anknytning till platsen. De för ett teoretiskt och nÄgot filosofiskt resonemang kring detta och sluter sig till att platser förutsÀtter mÀnniskor och deras kÀnslor kopplade till platsen, utan dessa Àr platsen blott ett utrymme. Detta synsÀtt förutsÀtter alltsÄ att mÀnskliga upplevelser har en rumslig dimension. För att möjliggöra en konkret kartering av upplevelserna kokar Thwaites och Simkins ned mÀnniskans upplevelse i tre grundlÀggande kategorier: betydelsebildning, orientering och hur hon skiljer pÄ olika omrÄden. Dessa kategorier visar sig sedan i karteringen som centrum(betydelsebildning), riktning och övergÄng (orientering), samt dÄ omrÄde (omrÄde). I karteringen skiljs dessutom pÄ olika typer inom dessa rubriker, och samtliga kategorier har negativa variationer.
Utöver min egen analys har jag haft förberedda frÄgor att stÀlla till personer som befann sig pÄ platserna. FrÄgorna Àr hÀmtade ur Experiential landscape: an approach to people, place and space (Thwaites & Simkins, 2007), med tillÀgg som kunde tÀnkas leda till att intervjupersonerna sjÀlva tog upp Àmnet graffiti, om inte sÄ skedde har jag sjÀlv fört det pÄ tal.
Tjurbergsparken beskrivs i en sociotopkartering som en grön oas, men i utvecklingsbehov för sociala och kulturella vÀrden (Stadsbyggnadskontoret, 2004). Parken bestÄr av klippta grÀsmattor med genomkorsande gÄngstigar, en del buskage och ett varierat bestÄnd av stora och mindre trÀd av olika arter. Platsen ligger i sin helhet i en södersluttning och högst upp finns en hög stödmur vilken avgrÀnsar parken frÄn Engelska gymnasiets skolgÄrd.
Resultatet visade att parken innehöll en faktor som jag inte rĂ€knat med, platsen Ă€r en umgĂ€ngesplats för hemlösa och missbrukare. I och med den funna situationen Ă€r det ofrĂ„nkomligt att inte diskutera frĂ„gor som har med nyttjanderĂ€tt av offentliga rum att göra. Missbrukare och hemlösa har samma rĂ€tt som andra att anvĂ€nda parken som smĂ„barnsförĂ€ldrar och flanerande pensionĂ€rer. Verkligheten Ă€r emellertid sĂ„dan att vissa personer pĂ„ grund av förutfattade meningar och möjligtvis ett avvikande beteende stöter bort andra och skapar negativa spĂ€nningar inom en plats. Detta var framtrĂ€dande pĂ„ platsen, graffiti var dock inget som intervjupersonerna âsjĂ€lvmantâ tog upp, trots förekomst av detta pĂ„ muren. GraffitimĂ„lare Ă€r förstĂ„s vĂ€lkomna i parken förutsatt att de inte utövar sitt intresse pĂ„ muren, det visar sig ocksĂ„ under intervjuerna att aktiviteten olagligt graffitimĂ„leri inte skulle bemötas sĂ€rskilt positivt. Resultatet visar dock inget större motstĂ„nd mot graffiti som laglig aktivitet i parken, och bekrĂ€ftar i stort att effekten av en laglig graffitivĂ€gg hĂ€r Ă€r förenliga med min tolkning av de mĂ„l klotterpolicyn beskriver. Dess största förtjĂ€nst i Tjurbergsparken borde enligt min bedömning vara den förbĂ€ttrade sociala situationen, och en ökad trygghet.
Zinkensdamms idrottsplats avgrĂ€nsas mot RingvĂ€gen av en mur, vilken löper lĂ€ngs trottoaren ungefĂ€r 120 meter lĂ„ng. Det finns fĂ„ funktioner i omrĂ„det, och analysen visar att det Ă€r mest en genomströmningsplats. Ă
sikter om muren var mer förekommande Àn i Tjurberget, det vanliga svaret var att den Àr trÄkig och ful, vilket med murens dominans Àven kan sÀgas karaktÀriserar platsen. Spontana förslag om fÀrg och Àven graffiti pÄ muren var inte ovanliga. För att sammanfatta skillnaden mellan nuvarande situation och en verklighet dÀr det vore möjligt för vem som helst att lagligt mÄla pÄ muren; En funktion adderas till en hÀndelsefattig plats vilket gör att fler personer faktiskt skulle uppehÄlla sig pÄ platsen, promenaden lÀngs Zinkensdamms IP skulle bli intressantare och erbjuda bÀttre möjligheter för möten. Eftersom utrymmet skulle ha en högre förekomst av mÀnsklig erfarenhet och ha fler kÀnslor kopplade till den, skulle rummet mer utgöra plats. Den skulle helt enkelt ha en starkare identitet och ha mer betydelse Àn i nuvarande situation.
En ren och snygg stad Ă€r (precis som övrigt i klotterpolicyns mĂ„l) troligtvis nĂ„got som de allra flesta av staden invĂ„nare anser önskvĂ€rt, dock Ă€r dessa adjektiv högst subjektiva och det Ă€r svĂ„rt att hitta en medelvĂ€g, vilket inte heller verkar sĂ€rskilt Ă„trĂ„vĂ€rt. En attraktiv stad har en mĂ„ngfald av uttryck och upplevelser. Vi Ă„terkommer till att staden Ă€r en kompromiss, men dĂ€r allas önskemĂ„l ocksĂ„ i sĂ„ stor utstrĂ€ckning som möjligt skall kunna tillgodoses. Möjligheten för den enskilde att sĂ€tta avtryck i staden Ă€r dock vĂ€ldigt begrĂ€nsad, graffiti Ă€r ett urbant kulturuttryck och lagliga möjligheter för detta ger inte bara tillfĂ€lle för personliga avtryck, det skapar ocksĂ„ ett mer mĂ„ngfacetterat stadsrum och Ă€r ett medel för att uppnĂ„ de mĂ„l klotterpolicyn efterstrĂ€var. En mer nyanserad syn pĂ„ fenomenet graffiti ger ocksĂ„ nya möjligheter i planeringssammanhang.This is a thesis of 30 credits completed in 2012 at the Department of Urban and Rural Development at SLU, Ultuna, Sweden. The background for the thesis is that Stockholm City Council has for several years had a very repressive attitude towards the phenomenon of graffiti, a zero tolerance policy. In 2007 the city adopted a stricter graffiti policy which states that: âThe city should not engage in or support activities or events that doesnât clearly distance themselves from tagging, illegal graffiti and similar vandalism. The city should also not contribute to activities which in no way can spark interest and lead to tagging, illegal graffiti or other vandalismâ.
The graffiti policy and in particular the above formulation has endured much criticism, especially after the city questioned and took measures against various cultural events with graffiti themes. Nevertheless, a total prohibition of opportunities for those interested in graffiti is not the only approach to curb the problems with vandalism that graffiti entails. The National Council for Crime Preventions report Graffitiförebyggande Ă„tgĂ€rder (Hollari, 2005) explores a number of examples of how other cities in different ways have treated the problems. Creating opportunities for graffiti painting is often one of the strategies. Such possibilities, which at first glance seem pragmatic, are rendered impossible as a consequence of Stockholm Cityâs Graffiti Policy. The cityâs reasoning behind this is the claim that providing such facilities inevitable leads to an increase in illegal graffiti. This claim was originally presented as fact (SVT, 2010) but later changed to opinion, an opinion zero tolerance advocates believe in (Riksteatern, 2011). The debate on the zero tolerance policy often circles around whether this statement is true or not, and on if its arbitrariness infringe on free speech, and acts as censorship on cultural expression.
This essay is about legal graffiti walls, however, not from the previously mentioned approaches. The aim is to show what the general effect of legal graffiti can be in the places where it might be possible. the Graffiti Policyâs description of aims has been the starting point for this. What is sought after is this: âStockholm will be a safe, secure, clean and beautiful city that we are proud of and where the urban environment invites interaction between people.â
My theory is that a legal graffiti wall, just like any other function in the city, attracts people, and in doing so may act in favour of the Graffiti Policyâs aims and goals that all residents probably desire.
The Graffiti Policyâs mission statement has been scrutinized bit by bit to discuss and offer a deeper understanding of the concepts it contains. Under the heading Safety a background is provided and the idea that graffiti creates insecurity is challenged. The conclusion is more or less that graffiti artists have been portrayed as âdangerousâ people and since graffiti writing is something that only occurs in secret, the public have few chances to meet artists and form their own opinions about them. The phenomenon is something unfamiliar, which is a breeding ground for insecurity. Regarding security, I state that a legal graffiti wall would populate the area, which according to Jane Jacobs (1962) is positive from a safety perspective. Beauty is a relative term and I argue that the city is a compromise in the sense that we have to live with the expressions it contains. As ordinary citizens, we have few opportunities to influence the townscape. Graffiti has its origins in public and therein lies itâs potential, legal graffiti could be one of the otherwise very few opportunities for the public to contribute and put their imprint on urban space. Another consequence of the zero tolerance policy is that ordinary people will be less exposed to sophisticated graffiti that takes a long time to produce. Instead, the public to a greater extent gets to experience quickly executed graffiti, so called âtaggingâ, which generally is looked upon as less desirable. The adjective clean is also a very broad and subjective concept, my reasoning on this is heavily based on the geographer David Harveyâs (2008) ideas. It is mainly from the perspective of Stockholm as a product that the concept of clean has been defined. A city that is advertised as clean and how the market views the concept need not always be consistent with the desires and wishes of its residents. Concerning pride and legal graffiti I put it in relation to the Cultural Vision 2030, an official plan directed by the city regarding the future cultural development of Stockholm. Graffiti is in my eyes primarily an artistic activity and part of cultural property. Culture is mankindâs expression, and pride has a great part to play in this. The Cultural Vision has big ambition and great goals and graffiti could contribute to these goals but cannot, as long as the Graffiti Policy is in effect. A legal graffiti wall would attract people to paint on it. Human activity, according to Jan Gehl (2006) is a great attraction, if not the strongest, on other people. With this argument and the fact that legal possibilities for graffiti provide an alternative to illegal painting, an activity that severely can limit peopleâs future prospects, I would argue that legal graffiti walls increase interaction between people.
The approach has been that of Jan Gehls (2006) categorization of sites in low and high quality, with much voluntary activity characterizing the latter. Through a social networking website, I got tips on places where legal graffiti according to graffiti writers themselves is desirable, then selected two sites based on the aforementioned criteria and assessed their suitability as sites for legal graffiti. The choice fell on Tjurbergsparken which represents a high quality site and the pavement alongside Zinkensdamm IP, a place of low quality, both located on Södermalm in Stockholm. To get a deeper understanding of how these sites work, I have analyzed the sites with a method called experiential landscape. Kevin Thwaites and Ian Simkins (2007) developed this method which stresses that it is the relationship between man and space that create the site, and the analysis aims at mapping the human experience and emotional attachment to a specific place. They have a theoretical and somewhat philosophical discussion regarding this and conclude that any site requires people and their feelings related to the site, without this a space cannot constitute a place. This point of view inevitably means that human experience have spatial dimensions. To allow a visual mapping of experiences Thwaites and Simkins condense human experience into three basic categories: the attachment of significance and value, orientation, and how a person develops a sense of home ground or coherence in an area. To be able to read the experiential potentials in a mapping the categories are represented in four types of symbols. These are the centre (significance and value), direction and transition (orientation), as well as area (coherence). There are also a few sub-categories and every variation can have a negative version.
In addition to my own analysis, I had prepared questions to ask the people who were on the sites. The questions are taken from Experiential landscape: an approach to people, place and space (Thwaites & Simkins, 2007), with some additions that might lead to the interviewees themselves speaking on the subject of graffiti, if they did not, I myself brought it up.
Tjurbergsparken is described in a mapping describing social and functional qualities as a green oasis, but with a need for further development of social and cultural values (Stadsbyggnadskontoret, 2003). The park consists of mowed lawns with intersecting paths, some shrubbery and a number of large and small trees of various species. The site is located entirely in a south-facing slope and at the top there is a high retaining wall which separates the park from a high school and its schoolyard.
The analysis results showed that the park carried a factor that I did not expect; the place is a socializing spot for the homeless and drug addicts. With this information retrieved, it is impossible not to discuss issues regarding right to access and the use of public space. Substance abusers and the homeless have all the same right to use the park as toddlers with their parents or pensioners do. The reality is such that some people because of prejudice and possibly antisocial behavior repel others and create negative tension at certain places. This was prominent on the site, graffiti however, was not something that the respondents âvoluntarilyâ took up, despite the occurrence of this on the wall. Graffiti writers are of course welcome in the park provided they do not exercise their interest on the wall. During the interviews it also became evident that the activity of illegal graffiti writing would not be looked upon with approval. Nevertheless, the result show no greater resistance to graffiti as an officially recognized activity in the park, and largely confirms that the effect of a legal graffiti wall here consistent with my understanding of the objectives the Graffiti Policy describes. Its greatest merit in Tjurbergsparken should in my opinion be the improved social conditions, and increased security.
Zinkensdamms sports ground is separated from RingvÀgen with a wall which runs along the pavement about 120 meters long. There are few functions in the area, and the analysis shows that this is mostly a place to pass by. Opinions on the wall were more prevalent than in Tjurbergsparken, the usual answer was that it is boring and ugly, as with the wall dominance can also be said to characterize the site. Unsolicited proposals for color and even graffiti on the wall were not uncommon. To summarize the difference between the current situation and one with a possibility for anyone to legally paint on the wall: A feature added to an uneventful place would result in more people actually staying at the site, the passing of Zinkensdamm IP would be more interesting and provide better opportunities for socializing. As the space would have a higher prevalence of human experience and have more emotion connected to it, the site would constitute a place. The site would simply put have a stronger identity and have greater significance.
A clean and tidy town is (just like the rest of what the Graffiti Policy is aiming for) probably something that the vast majority of city residents consider desirable, however, these adjectives are highly subjective and it is difficult to find a common ground, which either way does not seem very appealing. An attractive city has a variety of expressions and experiences. We return to the fact that the city is a compromise, but where everyoneâs wishes as far as possible are to be satisfied. The ability for individuals to express themselves in the city is
Estimation of abrasion on flint shingle beaches in East Sussex, UK.
In situ abrasion of shingle beach material is a neglected area of study in coastal geomorphology, with reduction in beach volumes normally attributed to longshore and offshore drift. Results from field abrasion experiments conducted on flint shingle beaches on the East Sussex coast, southern England, show that in situ reductions in volume of beach material may be more significant than has been thought. Two beaches composed almost entirely of flint shingle were seeded with hard quartzite from a Devon beach and less resistant limestone from a South Wales beach that are readily distinguishable from the flint. The seeding commenced in January 2001. The pebbles, similar in size and shape to the natural flint shingle, were left in the surf zone at two sites. Prior to exposure the pebbles were engraved with a code number and weighed. At regular intervals those that could be re-found were re-weighed and returned to the beach. Abrasion rates were calculated for each pebble as percentage weight loss per tide. By the end of October 2001, more than 700 measurements of abrasion rates had been made from a total of 431 pebbles. Average limestone abrasion rates (0.0266% loss of weight per tide) were three times greater than those of quartzite (0.0082% per tide). Measurable abrasion rates were recorded over just a few tidal cycles, not only in severe wave conditions but also in much calmer weather. The maximum abrasion rates recorded exceeded 1% per tide for limeston
Reify Your Collection Queries for Modularity and Speed!
Modularity and efficiency are often contradicting requirements, such that
programers have to trade one for the other. We analyze this dilemma in the
context of programs operating on collections. Performance-critical code using
collections need often to be hand-optimized, leading to non-modular, brittle,
and redundant code. In principle, this dilemma could be avoided by automatic
collection-specific optimizations, such as fusion of collection traversals,
usage of indexing, or reordering of filters. Unfortunately, it is not obvious
how to encode such optimizations in terms of ordinary collection APIs, because
the program operating on the collections is not reified and hence cannot be
analyzed.
We propose SQuOpt, the Scala Query Optimizer--a deep embedding of the Scala
collections API that allows such analyses and optimizations to be defined and
executed within Scala, without relying on external tools or compiler
extensions. SQuOpt provides the same "look and feel" (syntax and static typing
guarantees) as the standard collections API. We evaluate SQuOpt by
re-implementing several code analyses of the Findbugs tool using SQuOpt, show
average speedups of 12x with a maximum of 12800x and hence demonstrate that
SQuOpt can reconcile modularity and efficiency in real-world applications.Comment: 20 page
Nonlinear viscous damping and tuned mass damper design for occupant comfort in flexible tall buildings subjected to wind loading
During wind events, tall buildings may exhibit floor accelerations levels that compromise occupant comfort. The use of energy dissipating devices to reduce peak floor accelerations is a sound strategy to improve building performance. The estimation of mean peak floor accelerations of a steel-frame building subjected to random wind forces and the design procedure of supplemental nonlinear viscous dampers to improve occupant comfort in one-year recurrence wind events are described in this paper. A stochastic wind load model is developed to estimate acceleration performance; drag, lift and torsional moments at each story are defined as random stationary processes by the definition of their cross-spectral density matrix. Wind tunnel results and computational fluid dynamic analyses are used to fine-tune the stochastic load models. Reduced-order structural models of the tower are developed to estimate the frequency response function from floor loadings to floor accelerations at corners points of the buildings. Statistical linearization is used to estimate the performance of the buildings with non-linear viscous dampers installed in different configurations. Floor acceleration reductions achieved with supplemental viscous dampers and a tuned mass damper are evaluated to comply with occupant performance standards.Publicado en: MecĂĄnica Computacional vol. XXXV, no. 12Facultad de IngenierĂ
Nonlinear viscous damping and tuned mass damper design for occupant comfort in flexible tall buildings subjected to wind loading
During wind events, tall buildings may exhibit floor accelerations levels that compromise occupant comfort. The use of energy dissipating devices to reduce peak floor accelerations is a sound strategy to improve building performance. The estimation of mean peak floor accelerations of a steel-frame building subjected to random wind forces and the design procedure of supplemental nonlinear viscous dampers to improve occupant comfort in one-year recurrence wind events are described in this paper. A stochastic wind load model is developed to estimate acceleration performance; drag, lift and torsional moments at each story are defined as random stationary processes by the definition of their cross-spectral density matrix. Wind tunnel results and computational fluid dynamic analyses are used to fine-tune the stochastic load models. Reduced-order structural models of the tower are developed to estimate the frequency response function from floor loadings to floor accelerations at corners points of the buildings. Statistical linearization is used to estimate the performance of the buildings with non-linear viscous dampers installed in different configurations. Floor acceleration reductions achieved with supplemental viscous dampers and a tuned mass damper are evaluated to comply with occupant performance standards.Publicado en: MecĂĄnica Computacional vol. XXXV, no. 12Facultad de IngenierĂ
Nonlinear viscous damping and tuned mass damper design for occupant comfort in flexible tall buildings subjected to wind loading
During wind events, tall buildings may exhibit floor accelerations levels that compromise occupant comfort. The use of energy dissipating devices to reduce peak floor accelerations is a sound strategy to improve building performance. The estimation of mean peak floor accelerations of a steel-frame building subjected to random wind forces and the design procedure of supplemental nonlinear viscous dampers to improve occupant comfort in one-year recurrence wind events are described in this paper. A stochastic wind load model is developed to estimate acceleration performance; drag, lift and torsional moments at each story are defined as random stationary processes by the definition of their cross-spectral density matrix. Wind tunnel results and computational fluid dynamic analyses are used to fine-tune the stochastic load models. Reduced-order structural models of the tower are developed to estimate the frequency response function from floor loadings to floor accelerations at corners points of the buildings. Statistical linearization is used to estimate the performance of the buildings with non-linear viscous dampers installed in different configurations. Floor acceleration reductions achieved with supplemental viscous dampers and a tuned mass damper are evaluated to comply with occupant performance standards.Publicado en: MecĂĄnica Computacional vol. XXXV, no. 12Facultad de IngenierĂ
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