50 resultados para state feedback
Resumo:
We present the first observation in hadronic collisions of the electroweak production of vector boson pairs (VV, V=W, Z) where one boson decays to a dijet final state. The data correspond to 3.5 fb-1 of integrated luminosity of pp̅ collisions at √s=1.96 TeV collected by the CDF II detector at the Fermilab Tevatron. We observe 1516±239(stat)±144(syst) diboson candidate events and measure a cross section σ(pp̅ →VV+X) of 18.0±2.8(stat)±2.4(syst)±1.1(lumi) pb, in agreement with the expectations of the standard model.
Resumo:
We present the first observation in hadronic collisions of the electroweak production of vector boson pairs (VV, V=W,Z) where one boson decays to a dijet final state . The data correspond to 3.5 inverse femtobarns of integrated luminosity of ppbar collisions at sqrt(s)=1.96 TeV collected by the CDFII detector at the Fermilab Tevatron. We observe 1516+/-239(stat)+/-144(syst) diboson candidate events and measure a cross section sigma(ppbar->VV+X) of 18.0+/-2.8(stat)+/-2.4(syst)+/-1.1(lumi) pb, in agreement with the expectations of the standard model.
Resumo:
In Somalia the central government collapsed in 1991 and since then state failure became a widespread phenomenon and one of the greatest political and humanitarian problems facing the world in this century. Thus, the main objective of this research is to answer the following question: What went wrong? Most of the existing literature on the political economy of conflict starts from the assumption that state in Africa is predatory by nature. Unlike these studies, the present research, although it uses predation theory, starts from the social contract approach of state definition. Therefore, rather than contemplating actions and policies of the rulers alone, this approach allows us to deliberately bring the role of the society – as citizens – and other players into the analyses. In Chapter 1, after introducing the study, a simple principal-agent model will be developed to check the logical consistence of the argument and to make the identification of causal mechanism easier. I also identify three main actors in the process of state failure in Somalia: the Somali state, Somali society and the superpowers. In Chapter 2, so as to understand the incentives, preferences and constraints of each player in the state failure game, I in some depth analyse the evolution and structure of three central informal institutions: identity based patronage system of leadership, political tribalism, and the Cold War. These three institutions are considered as the rules of the game in the Somali state failure. Chapter 3 summarises the successive civilian governments’ achievements and failures (1960-69) concerning the main national goals, national unification and socio-economic development. Chapter 4 shows that the military regime, although it assumed power through extralegal means, served to some extent the developmental interest of the citizens in the first five years of its rule. Chapter 5 shows the process, and the factors involved, of the military regime’s self-transformation from being an agent for the developmental interests of the society to a predatory state that not only undermines the interests of the society but that also destroys the state itself. Chapter 6 addresses the process of disintegration of the post-colonial state of Somalia. The chapter shows how the regime’s merciless reactions to political ventures by power-seeking opposition leaders shattered the entire country and wrecked the state institutions. Chapter 7 concludes the study by summarising the main findings: due to the incentive structures generated by the informal institutions, the formal state institutions fell apart.
Resumo:
This master thesis studies how trade liberalization affects the firm-level productivity and industrial evolution. To do so, I built a dynamic model that considers firm-level productivity as endogenous to investigate the influence of trade on firm’s productivity and the market structure. In the framework, heterogeneous firms in the same industry operate differently in equilibrium. Specifically, firms are ex ante identical but heterogeneity arises as an equilibrium outcome. Under the setting of monopolistic competition, this type of model yields an industry that is represented not by a steady-state outcome, but by an evolution that rely on the decisions made by individual firms. I prove that trade liberalization has a general positive impact on technological adoption rates and hence increases the firm-level productivity. Besides, this endogenous technology adoption model also captures the stylized facts: exporting firms are larger and more productive than their non-exporting counterparts in the same sector. I assume that the number of firms is endogenous, since, according to the empirical literature, the industrial evolution shows considerably different patterns across countries; some industries experience large scale of firms’ exit in the period of contracting market shares, while some industries display relative stable number of firms or gradually increase quantities. The special word “shakeout” is used to describe the dramatic decrease in the number of firms. In order to explain the causes of shakeout, I construct a model where forward-looking firms decide to enter and exit the market on the basis of their state of technology. In equilibrium, firms choose different dates to adopt innovation which generate a gradual diffusion process. It is exactly this gradual diffusion process that generates the rapid, large-scale exit phenomenon. Specifically, it demonstrates that there is a positive feedback between firm’s exit and adoption, the reduction in the number of firms increases the incentives for remaining firms to adopt innovation. Therefore, in the setting of complete information, this model not only generates a shakeout but also captures the stability of an industry. However, the solely national view of industrial evolution neglects the importance of international trade in determining the shape of market structure. In particular, I show that the higher trade barriers lead to more fragile markets, encouraging the over-entry in the initial stage of industry life cycle and raising the probability of a shakeout. Therefore, more liberalized trade generates more stable market structure from both national and international viewpoints. The main references are Ederington and McCalman(2008,2009).
Resumo:
Työssäni tarkastelen venäläistä neo-euraasianistista liikettä ja tapoja joilla liikkeen aktivistit rakentavat Euraasiasta yhtenäistä kokonaisuutta ja imperiumia. Keskeisiä tutkimuskysymyksiäni ovat: Mikä imperiumi on ja mitkä ovat sen keskeisiä motivaatioita ja teemoja? Kuinka imperiumin idea rakentuu tai käsitetään ja tämän voi tulkita? Minkälaisia seurauksia voi tulkita heidän tavallaan Euraasia nähdä olevan? Materiaalina käytän haastatteluja, jotka on kerätty Moskovassa keväällä 2008, ja liikkeen kirjallisia tuotoksia (lehdet ja Internet -sivut). Neo-euraasianistisella liikkeellä tarkoitan tässä työssä Kansainvälistä Euraasianistista liikettä (Meždunarodnoe Evrazijskoe Dviženie) ja sen alahaaraa Euraasianistista Nuorisoliittoa (Evrazijskij Sojuz Molodëži). Liike perustettiin virallisesti 2003, mutta rakentaa vahvasti historiallista yhteyttä 1930 -luvun klassiseen eurasianismiin. Tämän lisäksi sen diskurssissa on paljon neuvostoliittolaisia, fasistisia, uuskonservatiivisia ja nationalistisia piirteitä. Liikkeen johtohahmo on filosofi-geopoliitikko Alexandr Dugin. Työn tausta-ajatuksena minua kiinnostaa etenkin nk. älymystön tai intelligenttien vaikutus nationalismiin tai sosiaalisia ryhmiä määrittelevien diskurssien kehitykseen ja muutokseen.Tarkastelen materiaalia diskurssianalyyttisesta näkökulmasta. Näen diskurssianalyysin sen tutkimisena, miten sosiaalista todellisuutta tuotetaan erilaisissa sosiaalisissa käytännöissä. Samalla näiden diskurssien tutkiminen, foucautlaisen perinteen myötä, tarkastelee kriittisesti niiden tuottamia (aktualisoituneita sekä potentiaalisia) valtasuhteita. Käytän työssäni myös Benedict Andersonin kuvitellun yhteisön (imagined communities) käsitettä, joka auttaa hahmottamaan tapaa, jolla tutkimuskohteeni rakentavat imperiumia yhteisönä. Aktivistien puheessa imperiumi (imperiâ) tulee esiin pääasiallisesti positiivisesti ja ”heidän omanaan,” kun taas termi imperialismi (imperializm) pääosin negatiivisena, liittyen etenkin keskeisenä vihollisena pidettyihin Yhdysvaltoihin. Esiin nousee monta toisiinsa liittyvää teemaa, jotka jaottelen viideksi pääteemaksi. Näistä tarkastelen lähemmin imperiumia ”kaikkien kansojen hyväntekijänä (poliittinen puoli)”, ulkoisen voiman lähteenä (historiallis-geopoliittinen puoli) sekä kollektiivisen subjektin luojana (imperialistis-nationalistinen puoli). Pyrin kontekstualisoimaan diskurssin ja tarkastelemaan tapoja, joilla se ammentaa motiiveja myös historiallis-kulttuurisista tavoista hahmottaa aluetta ja sen asukkaita. Käsittelen myös kansan, kansakunnan, etnoksen ja nationalismin käsitteitä ja sitä, miten ne nousevat neo-eurasianistisessa diskursissa esiin. Imperiaalisen nationalismin (imperskij nacionalizm) käsite auttaa ymmärtämään niitä tapoja, jolla liike tekee sekä pesäeroa nationalismiin että samalla hyödyntää monia nationalistisen diskurssin perusteemoja. Eräs liikkeen diskurssin keskeisistä eroista niin sanottuun nationalismin valtavirtaan on ”kansakunnan (naciâ)” käsitteen vahva negatiivinen konnotaatio. Sen vastakohtana esiin nostetaan vahvasti kansan (narod) käsite. Samalla kuitenkin etnisen venäläisen (russkij) käsitettä käytetään tavallista laajemmin ja kattavammin kuin tavallisesti, ja ennen kaikkea Venäjä nousee imperiumin keskeisimmäksi tekijäksi. Euraasialaiseen imperiumiin liitetyistä positiivistista mielikuvista käsittelen tarkemmin monikansallisuuden ja kansojen kodin ideaa, joka nousee mielestäni huomattavaksi retoriseksi taustaksi kaikessa materiaalissa. Tähän liittyy vahvasti myös saman teeman sivujuonne, eli imperiumin ”vapauttava” rooli. Tulkitsen, että liikkeen imperiumi -diskurssilla on instrumentaalinen luonne: se legitimoi aktivistien vaatimuksia varsinkin entisen Neuvostoliiton alueen suhteen. ”Euraasialaisen kansan” ajatus toimii mahdollisena Euraasiaa yhteisenä tekijänä ”Neuvostokansan” tilalla. Sen taustalla materiaalistani päätellen siintävät kuitenkin enemmänkin Venäjä ja venäläis -spesifit vaateet kuin koko Euraasia. Pohdin myös kansakunnan (nation) hyljeksimisen syitä ja käsitteen sopivuutta Venäjälle, kuten myös venäläisyyden käsitteiden kerrostuneisuutta. Kokonaisuudessaan imperiumi tuli esiin abstraktina, utopistisena ja ”totaalisena” kokonaisuutena.
Resumo:
The majority of Internet traffic use Transmission Control Protocol (TCP) as the transport level protocol. It provides a reliable ordered byte stream for the applications. However, applications such as live video streaming place an emphasis on timeliness over reliability. Also a smooth sending rate can be desirable over sharp changes in the sending rate. For these applications TCP is not necessarily suitable. Rate control attempts to address the demands of these applications. An important design feature in all rate control mechanisms is TCP friendliness. We should not negatively impact TCP performance since it is still the dominant protocol. Rate Control mechanisms are classified into two different mechanisms: window-based mechanisms and rate-based mechanisms. Window-based mechanisms increase their sending rate after a successful transfer of a window of packets similar to TCP. They typically decrease their sending rate sharply after a packet loss. Rate-based solutions control their sending rate in some other way. A large subset of rate-based solutions are called equation-based solutions. Equation-based solutions have a control equation which provides an allowed sending rate. Typically these rate-based solutions react slower to both packet losses and increases in available bandwidth making their sending rate smoother than that of window-based solutions. This report contains a survey of rate control mechanisms and a discussion of their relative strengths and weaknesses. A section is dedicated to a discussion on the enhancements in wireless environments. Another topic in the report is bandwidth estimation. Bandwidth estimation is divided into capacity estimation and available bandwidth estimation. We describe techniques that enable the calculation of a fair sending rate that can be used to create novel rate control mechanisms.
Resumo:
We report on a search for the production of the Higgs boson decaying to two bottom quarks accompanied by two additional quarks. The data sample used corresponds to an integrated luminosity of approximately 4 fb-1 of pp̅ collisions at √s=1.96 TeV recorded by the CDF II experiment. This search includes twice the integrated luminosity of the previous published result, uses analysis techniques to distinguish jets originating from light flavor quarks and those from gluon radiation, and adds sensitivity to a Higgs boson produced by vector boson fusion. We find no evidence of the Higgs boson and place limits on the Higgs boson production cross section for Higgs boson masses between 100 GeV/c2 and 150 GeV/c2 at the 95% confidence level. For a Higgs boson mass of 120 GeV/c2, the observed (expected) limit is 10.5 (20.0) times the predicted standard model cross section.
Resumo:
The subject of my doctoral thesis is the social contextuality of Finnish theater director, Jouko Turkka's (b. 1942) educational tenure in the Theater Academy of Finland 1982 1985. Jouko Turkka announced in the opening speech of his rectorship in 1982 that Finnish society had undergone a social shift into a new cultural age, and that actors needed new facilities like capacity, flexibility, and ability for renewal in their work. My sociological research reveals that Turkka adapted cultural practices and norms of new capitalism and new liberalism, and built a performance environment for actors' educational work, a real life simulation of a new capitalist workplace. Actors educational praxis became a cultural performance, a media spectacle. Turkka's tenure became the most commented upon and discussed era in Finnish postwar theater history. The sociological method of my thesis is to compare information of sociological research literature about new capitalist work, and Turkka's educational theater work. In regard to the conceptions of legitimation, time, dynamics, knowledge, and social narrative consubstantial changes occurred simultaneously in both contexts of workplace. I adapt systems and chaos theory's concepts and modules when researching how a theatrical performance self-organizes in a complex social space and the space of Information. Ilya Prigogine's chaos theoretic concept, fluctuation, is the central social and aesthetic concept of my thesis. The chaos theoretic conception of the world was reflected in actors' pedagogy and organizational renewals: the state of far from equilibrium was the prerequisite of creativity and progress. I interpret the social and theater's aesthetical fluctuations as the cultural metaphor of new capitalism. I define the wide cultural feedback created by Turkka's tenure of educational praxis, and ideas adapted from the social context into theater education, as an autopoietic communicative process between theater education and society: as a black box, theater converted the virtual conception of the world into a concrete form of an actor's psychophysical praxis. Theater educational praxis performed socially contextual meanings referring to a subject's position in the social change of 1980s Finland. My other theoretic framework lies close to the American performance theory, with its close ties to the social sciences, and to the tradition of rhetoric and communication: theater's rhetorical utility materializes quotidian cultural practices in a theatrical performance, and helps the audience to research social situations and cultural praxis by mirroring them and creating an explanatory frame.
Resumo:
We use parallel weighted finite-state transducers to implement a part-of-speech tagger, which obtains state-of-the-art accuracy when used to tag the Europarl corpora for Finnish, Swedish and English. Our system consists of a weighted lexicon and a guesser combined with a bigram model factored into two weighted transducers. We use both lemmas and tag sequences in the bigram model, which guarantees reliable bigram estimates.
Resumo:
In this paper we present simple methods for construction and evaluation of finite-state spell-checking tools using an existing finite-state lexical automaton, freely available finite-state tools and Internet corpora acquired from projects such as Wikipedia. As an example, we use a freely available open-source implementation of Finnish morphology, made with traditional finite-state morphology tools, and demonstrate rapid building of Northern Sámi and English spell checkers from tools and resources available from the Internet.
Resumo:
There are numerous formats for writing spellcheckers for open-source systems and there are many descriptions for languages written in these formats. Similarly, for word hyphenation by computer there are TEX rules for many languages. In this paper we demonstrate a method for converting these spell-checking lexicons and hyphenation rule sets into finite-state automata, and present a new finite-state based system for writer’s tools used in current open-source software such as Firefox, OpenOffice.org and enchant via the spell-checking library voikko.