Há basicamente dois sistemas empregados para promover a continuidade das terças de múltiplos vãos: transpasse e luva. Do ponto de vista do transporte e da montagem, o sistema de luvas é vantajoso em relação ao sistema de transpasse, uma vez que conduz a barras de menor comprimento. Entretanto, o emprego de luvas tem sido pouco explorado, devido principalmente ao pouco conhecimento sobre o comportamento estrutural do sistema e, consequentemente, pela ausência de recomendações de projeto disponibilizadas pelas normas e manuais técnicos. Neste trabalho foram analisadas a rigidez e a resistência de terças de seção transversal Z contínuas por meio de luvas. Para tanto, uma série de quinze protótipos de terças de aço formadas a frio foi submetida a ensaios de flexão, variando-se a altura do perfil, espessura e comprimento da luva e o vão. Foi conduzida uma análise da viabilidade do método da resistência direta (MRD) ao dimensionamento de terças contínuas por meio de luvas. Em relação à rigidez, curvas momento-rotação calibradas experimentalmente foram implementadas em modelos numéricos por meio de molas rotacionais, buscando simular o comportamento não linear da ligação. Posteriormente, uma análise paramétrica foi realizada, resultando na expressão momento-rotação proposta com base nas variáveis investigadas. Essa expressão representa a rigidez da ligação, que aliada a um modelo simples barra-mola, permite a avaliação mais precisa dos esforços solicitantes e deslocamentos de terças com luvas. / There are basically two systems employed to promote the continuity of multi-span purlins: overlap and sleeve. From the point of view of transport and assemblage, the sleeve system is advantageous in relation to the overlap system since it leads to shorter length bars. However, the use of sleeves has not been hardly explored mainly due to lack of knowledge about the system structural behavior and, therefore, the absence of design recommendations provided by standards and technical manuals. This study analyzed the stiffness and strength of continuous Z-section purlins with sleeved bolted connection. In order to develop the study a series of fifteen prototype were tested in bending; their cross-section height, thickness, sleeve length and span were varied. A viability analysis of the Direct Strength Method (DSM) for design of continuous sleeve purlins was conducted. In relation to stiffness, moment-rotation curves were calibrated experimentally and implemented in numerical models through rotational springs to simulate the nonlinear behavior of the connection. Afterwards, a moment-rotation expression based on the studied variables and a parametric analysis was proposed. This expression represents the connection stiffness and, when implemented in a simple spring-beam model, allows a more accurate prediction of the internal efforts and displacements in the purlin-sleeve system.

Traditionally, joints are assumed to be either pinned or fully rigid, but in reality, many behave between these two extremes giving them a semi-rigid classification. By acknowledging the semi-rigidity of nominal pin joints, steel frames can be designed as semi-continuous in which the beam bending moments are partially transmitted to the column members and the need for lateral bracing is eliminated, thus reducing material and construction costs. This thesis presents the results of numerical and theoretical studies of the behaviour of bolted endplate connections to Rectangular Hollow Section (RHS) columns using flowdrill bolts and their applications in semi-continuous frame design. Such connections exhibit significant levels of initial stiffness, strength, and deformation capacity while being more cost-effective than fully welded connections. Despite this, there is limited theoretical work carried out that allows such connections to be designed using analytical methods. In addition, there are no standardised connection design tables like that for open section columns (SCI, 1995), thereby inhibiting their adoption in practice. In this thesis, newly derived equations for initial stiffness that have a greatly improved range of validity and accuracy over existing equations are presented. Equations for bending strength of a newly derived elliptical mechanism based on yield line theory and for membrane action based on internal work principles are given. Equations for flowdrill thread stripping due to gross deformation of the RHS face are also presented thus allowing prediction of all common RHS face failure mechanisms. Equations for deformation capacity are derived thus making it possible to predict the full load-deflection behaviour of the RHS face in tension component. When combined with existing equations for bolt and endplate components, it is possible to predict the full moment-rotation behaviour of bolted endplate connections to RHS columns. Extensive parametric studies using finite element analysis (FEA) as well as validation against existing tests show that the newly derived equations can accurately predict the component-level and whole joint behaviour for a wide range of configurations. Taking advantage of the initial stiffness properties that these connections offer, a parametric study is conducted to show that connections with relatively simple detailing can offer sufficient initial stiffness and strength to enable unbraced semi-continuous design of low-rise steel frames. A hand calculation method for SLS sway in semi-continuous frames is also presented thus allowing the designer to readily carry out scheme designs without advanced software knowledge. A systematic method for the detailing of these connections for use in unbraced frame design is presented to facilitate adoption in practice.

No description available.

Constraint programming (CP) is a technology in which a combinatorial problem is modeled declaratively as a conjunction of constraints, each of which captures some of the combinatorial substructure of the problem. Constraints are more than a modeling convenience: every constraint is partially implemented by an inference algorithm, called a propagator, that rules out some but not necessarily all infeasible candidate values of one or more unknowns in the scope of the constraint. Interleaving propagation with systematic search leads to a powerful and complete solution method, combining a high degree of re-usability with natural, high-level modeling. A propagator can be characterized as a sound approximation of a constraint on an abstraction of sets of candidate values; propagators that share an abstraction are similar in the strength of the inference they perform when identifying infeasible candidate values. In this thesis, we consider abstractions of sets of candidate values that may be described by an elegant mathematical formalism, the Galois connection. We develop a theoretical framework from the correspondence between Galois connections and propagators, unifying two disparate views of the abstraction-propagation connection, namely the oft-overlooked distinction between representational and computational over-approximations. Our framework yields compact definitions of propagator strength, even in complicated cases (i.e., involving several types, or unknowns with internal structure); it also yields a method for the principled derivation of propagators from constraint definitions. We apply this framework to the extension of an existing CP solver to constraints over strings, that is, words of finite length. We define, via a Galois connection, an over-approximation for bounded-length strings, and demonstrate two different methods for implementing this overapproximation in a CP solver. First we use the Galois connection to derive a bounded-length string representation as an aggregation of existing scalar types; propagators for this representation are obtained by manual derivation, or automated synthesis, or a combination. Then we implement a string variable type, motivating design choices with knowledge gained from the construction of the over-approximation. The resulting CP solver extension not only substantially eases modeling for combinatorial string problems, but also leads to substantial efficiency improvements over prior CP methods.

This thesis is about how elected politicians stay in power and about some of its economic and social consequences, fundamental political economy questions. It takes advantage of the decentralized political structure in the Philippines to test models of voter and politician behavior. In doing so, it contributes to the literature on clientelism and retrospective voting. In Chapter One, I assess the impacts of targeted government transfers on a local incumbent's electoral performance. I use the randomized roll-out of a CCT program in the Philippines where a number of municipalities are tightly controlled by political dynasties. In a competitive political environment, incumbent vote share is 26 percentage-points higher in municipalities where the program was implemented in all villages than in municipalities where the program was implemented in half of them. The program had no impact in municipalities with low levels of political competition. In Chapter Two, I test for the presence of political business cycles in Philippine municipalities over the period 2003-2009, a context where according to the literature such cycles are likely to be observed. I find robust evidence for the presence of political business. This effect is only present when I use quarterly data and vanishes when I aggregate the data at the yearly-level. The difference is not merely driven by a decline in statistical power due to aggregation: point estimates for the overall effects are 7 times larger when I use quarterly data than when I use yearly data. This discrepancy can be explained by a drop in employment post-election that dilutes the yearly effects. In Chapter Three, we estimate the impacts of being connected to local politicians, either currently in office or in opposition, on occupational choice. We use a large administrative dataset collected between 2008 and 2010 on all individuals in 700 Philippine municipalities along with information on all candidates in the 2007 and 2010 municipal elections. We rely on local naming conventions to assess blood and marriage links between households. Using individuals connected to successful candidates in the 2010 elections that did not run in 2007 as a control group, we find that connections to current office-holders increase the likelihood of being employed in better paying occupations. Individuals connected to candidates that were close to being elected in 2007 are less likely to be employed in better paying occupations.

Differential geometry is about space (a manifold) and a geometric structure on that space. In Riemann’s lecture (see [17]), he stated that “Thus arises the problem, to discover the matters of fact from which the measure-relations of space may be determined...”. It is key then to understand how manifolds differ from one another geometrically. The results of this dissertation concern how the geometry of a manifold changes when we alter metrical connections. We investigate how diverse geodesics are in different metrical connections. From this, we investigate a new class of metrical connections which are dependent on the class of smooth functions. Specifically, we fix a Riemannian metric and investigate the geometry of the manifold when we change the metrical connections associated with the fixed Riemannian metric. We measure the change in the Riemannian curvatures associated with this new class of metrical connections, and then give uniqueness and existence criterion for curvature of compact 2-manifolds. These results depend on the use of Hodge Theory and ultimately on the function f we choose to define a metrical connection.

Baigiamajame magistro darbe nagrinėjama Vilniaus Paupio ir Palaujos istorinio priemiesčio urbanistinė erdvinė struktūra ir su ja susijusios urbanistinės plėtros problemos. Tyrinėjama Vilniaus centrinės dalies kokybinė funkcinių-kompozicinių urbanizacijos branduolių sistemos plėtra. Apžvelgiama Paupio ir Plaujos teritorijos istorinė raida, identifikuojami esami vertingi struktūros elementai ir lokalizuojamos rekonstrukcijos zonos, vertinamas galimos plėtros poveikis vizualiniam Vilniaus miesto centrinės dalies identitetui. Remiantis atliktomis analizėmis ir teritorijos dalies kaip įvaizdžio mazgo potencialu, pateikiamos nagrinėjamos teritorijos erdvinio karkaso plėtros alternatyvos. Apžvelgus pramoninių teritorijų konversijos problematiką ir galimybes, pagal pasirinktą alternatyvą parengta Paupio ir Paplaujos teritorijos konversijos ir daugiafunkcinio centro koncepcija. Daugiafunkcinis centras sprendžiamas kaip funkcinė jungtis tarp dviejų struktūrinių urbanistinių teritorijų per fizinį barjerą – Zarasų gatvę. Darbo pabaigoje pateikiamos išvados ir siūlymai. / The final thesis examines the historic suburb of Paupys and Paplauja in Vilnius urban spatial structure and the associated urban development problems. The qualitative, functional composite urbanized core system development of the central part of Vilnius is examined. A survey of historical urban development is made, identified existing valuable elements of spatial structure, localized areas of reconstruction, analyzed possibilities and results of further development, evaluated the potential development of the visual impact of the central part of Vilnius city identity. According to the analysis and part of the territory's image as a potential host, strategic alternatives of urban spatial structure development in the territory are proposed. A review of the problems and opportunities of conversion of industrial sites revealed the concept of the urban development of territory and multi-center. Further work was made on compositional quality of urban spaces and detailing of multi-center. In the end conclusions and proposals were made.

Evidence suggests that high-level feedback plays an important role in visual perception by shaping the response in lower cortical levels (Sillito et al. 2006, Angelucci and Bullier 2003, Bullier 2001, Harrison et al. 2007). A notable example of this is reflected by the retinotopic activation of V1 and V2 neurons in response to illusory contours, such as Kanizsa figures, which has been reported in numerous studies (Maertens et al. 2008, Seghier and Vuilleumier 2006, Halgren et al. 2003, Lee 2003, Lee and Nguyen 2001). The illusory contour activity emerges first in lateral occipital cortex (LOC), then in V2 and finally in V1, strongly suggesting that the response is driven by feedback connections. Generative models and Bayesian belief propagation have been suggested to provide a theoretical framework that can account for feedback connectivity, explain psychophysical and physiological results, and map well onto the hierarchical distributed cortical connectivity (Friston and Kiebel 2009, Dayan et al. 1995, Knill and Richards 1996, Geisler and Kersten 2002, Yuille and Kersten 2006, Deneve 2008a, George and Hawkins 2009, Lee and Mumford 2003, Rao 2006, Litvak and Ullman 2009, Steimer et al. 2009). The present study explores the role of feedback in object perception, taking as a starting point the HMAX model, a biologically inspired hierarchical model of object recognition (Riesenhuber and Poggio 1999, Serre et al. 2007b), and extending it to include feedback connectivity. A Bayesian network that captures the structure and properties of the HMAX model is developed, replacing the classical deterministic view with a probabilistic interpretation. The proposed model approximates the selectivity and invariance operations of the HMAX model using the belief propagation algorithm. Hence, the model not only achieves successful feedforward recognition invariant to position and size, but is also able to reproduce modulatory effects of higher-level feedback, such as illusory contour completion, attention and mental imagery. Overall, the model provides a biophysiologically plausible interpretation, based on state-of-theart probabilistic approaches and supported by current experimental evidence, of the interaction between top-down global feedback and bottom-up local evidence in the context of hierarchical object perception.

The aim of this thesis is to on one hand give a good overview of finds found in gotlandic stonefoundationhouses (kämpgravar) that were commonly built during the Iron Age and on the other hand investigate the possibility of separating some houses from others and trace social stratification and hierarchies based on the finds. The items of special interest for this goal were those that could be connected to wealth such as drinking objects, Roman objects and objects made of silver and gold. This investigation has shown that on Gotland it actually existed some, often enormous, houses that had a special tendency to hoard exotic valuables. The real standout houses on this subject are the one in Stavgard and the recently excavated building in Hellvi. A secondart goal was to investigate the possibility to date the buildings based on the finds, which was found to be very problematic. (Two years master’s thesis in Archaeology) / Det huvudsakliga målet med denna uppsats är dels att ge bra överblick över fynden som påträffats i de gotländska stengrundshusen (kämpgravar) som byggdes flitigt under järnåldern och att dels se om det är möjligt att separera vissa hus från andra och spåra social stratifikation och hierarkier baserat på fyndmaterialet. De föremål som var av speciellt intresse för detta mål är de som kan kopplas till rikedom såsom exempelvis exotiska dryckesföremål, romerska föremål och föremål av ädelmetall. Undersökningen har visat att det på Gotland faktiskt fanns en del, ofta enorma, hus som hade en speciell benägenhet att hamstra exotiska dyrgripar. De riktiga utstickarna på det här temat är huset känt som Stavgard och även den nyligen undersökta byggnaden i Hellvi. Båda hade rika mängder av dryckesobjekt såsom glaskärl och dryckeshorn och en del, för ön, unika romerska föremål. Ett sidomål var att även undersöka möjligheten att datera husen baserat på fynden, vilket visade sig vara högst problematiskt. (Master-uppsats i Arkeologi)

Syfte: Syftet med arbetet är att förbättra dimensioneringsprocessen för knutpunkter i stålstrukturer. Förslag har getts på en förbättrad dimensionsprocess baserad på de BIMrelaterade datorprogrammen SBI Steel Connections och FEM-design. Syftet har brutits ner till följande frågeställningar:  Hur går konsultföretag till väga idag för att beräkna knutpunkter vid stålkonstruktioner?  Hur kan den vanligaste dimensioneringsprocessen för knutpunkter förbättras?  Vilka fördelar blir det vid en sammankoppling av de BIM-relaterade datorprogrammen SBI Steel Connections och FEM-design? Metod: Arbetet grundar sig i en fallstudie och ett flertal metoder användes för att samla in data. Dessa är semistrukturerade intervjuer, litteratursökning, dokumentanalys och beräkningar. Resultat: Genom arbetet framgår det hur dimensioneringsprocessen ser ut för knutpunkter i stål. Resultatet är att processen varierar beroende på företag. Vissa delar i processen kan utföras på olika sätt men grundprincipen är densamma för de flesta företagen som har intervjuats. Vid dimensionering av knutpunkter som kan ske både för hand och med hjälp av ett datorprogram kan det uppstå felslag vid inmatning eller felskrivningar. Denna del av processen kan förbättras med hjälp av en ökad användning av egengjorda mallar. Det sker ett utvecklingsarbete under våren 2015 där målet är att skapa en sammankoppling mellan SBI Steel Connections och FEM-design. Genom denna sammankoppling reduceras några av de fel som anses tillhöra den mänskliga faktorn. Konsekvenser: Undersökningen har medfört en förståelse med både fördelar och nackdelar för olika sätt att dimensionera knutpunkter i stål. En del företag stävar efter en större utveckling, medan andra anser sig jobba bäst på det sätt som de alltid har gjort. Det framgår att den mänskliga faktorn är något som påverkar dimensioneringsprocessen märkbart och dessa fel behöver reduceras. De rekommendationer som framgår i arbetet är att företag ska se över processen och de förnyelsemöjligheter som finns i branschen. Det rekommenderas även en större användning av de datorprogram som används vid dimensioneringsprocessen. Begränsningar: Avgränsningar gjordes utifrån de kunskaper som erhållits i utbildningen för att studien inte skulle bli alltför omfattande. Däremot har ny kunskap bidragit till ett större ämnesdjup som utbildningen inte berört. Studien orienterades kring knutpunkter av stål och en av de vanligaste knutpunkterna studerades. Stålkvalitet och dimensioner på pelare och balk valdes utifrån knutpunktsexemplet i SBI:s handbok publikation 186 (PT3). Rapporten behandlar enbart beräkningsprogrammen SBI Steel Connections och FEM-Design. Detta medförde endast avgränsningar på material, val av knutpunkt, pelar- och balkprofiler samt laster.