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Control of machine drives for varying inertia systemsKaipio, Tero January 2000 (has links)
No description available.
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Hur hanterar man personalpolitik i en bransch som är både konjunkturkänslig och organiseras i projektform? : En intervjustudie om HRM i svenska byggföretag under en nedgångsfas på bostadsmarknadenBerggren-Lagercrantz, Leslie, Lundberg, Victor January 2019 (has links)
HRM eller Human Resource Management är det moderna begreppet för personalpolitik. Att hantera personal är en svår uppgift, i synnerhet under ekonomiska nedgångsfaser. Studiens primära syfte är att få en djupare förståelse för hur fem svenska byggföretag arbetar med sin HRM. Det sekundära syftet är att utreda vilka personalpolitiska förändringar som dessa byggföretag har genomfört och/eller planerar att genomföra under den pågående nedgångsfasen på bostadsmarknaden. Studien har baserats på semistrukturerade intervjuer med sammanlagt fem HR-chefer på Skanska AB, PEAB Bostad AB, JM AB, JM Entreprenad AB och HSB Bostad AB. Intervjufrågor som ställts har avgränsats till rekrytering och urval, personalutbildning och individuell kompetensutveckling, hanterandet av disciplin och klagomål samt hanterandet av belöningar. Det erhållna resultatet har analyserats med hjälp av en induktiv forskningsmetod. Byggföretagen har flera gemensamma drag. Vid rekrytering och urval väljer samtliga bolag extern rekrytering. Vid personalutbildning så koncentrerar sig samtliga bolag på både interna och externa utbildningar, förutom JM Entreprenad AB som numera enbart fokuserar på interna utbildningar. Att medarbetaren blir sedd samt att den får regelbunden feedback är viktigt enligt HR-cheferna och samtliga bolag, förutom HSB Bostad AB, använder sig av ett individuellt bonussystem. Under den pågående nedgångsfasen så har samtliga byggföretag, förutom Skanska AB, varit tvungna att antingen frysa rekryteringen eller reducera antalet medarbetare; detta i syfte att förbli konkurrenskraftiga. Enligt HR-cheferna så kommer byggföretagen bland annat att lägga mer fokus på att vidareutveckla försäljningskompetensen hos den nuvarande personalen. En av orsakerna till Skanska AB:s framgång kan vara att medarbetarna äger en stor del av Skanska Koncernen; detta motiverar dem att stanna kvar samt att arbeta hårdare.
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Deformation and strength of a cyclically bent threaded connection / Cikliškai lenkiamų srieginių jungčių deformavimas ir stiprumasJuchnevičius, Žilvinas 06 February 2012 (has links)
Industry equipment such as pressure vessels, mining equipment, heat exchang-ers, steam generators and other structures are provided with bolted closures for the purpose of in-service inspection and maintenance of internal components. Threaded connections often experience variable cyclic loads due to temperature, inner pressure and variation in the deformation of connection fittings. Often, studs and screws are not only affected by an axial load, but also by bending moments.
More sophisticated high-cycle and low-cycle durability calculation meth-odologies have been already developed for threaded connections experiencing cyclic axial loads, and in these methodologies the distribution of axial load among turns is assessed quantitatively. The quantitative data of load distribu-tion in the thread enables a more accurate assessment of the influence of the constructional design particularities (connection length, material, nut and turn’s form) and the deformation stages of the connection element.
These durability calculation methodologies are not applied for threaded connections that are cyclically bent, as the analytical models that are suitable for practical application in the load distribution of the turns have not been cre-ated for bent threaded connections. In this field, no models have been created to be calculated by the BE method.
As the threaded connection is a complex node consisting of deformed el-ements, the load distribution among turns is influenced by the... [to full text] / Srieginės jungtys dažnai patiria ciklinių lenkimo apkrovų dėl temperatū-ros, vidaus slėgio ir jungiamųjų detalių deformacijų kitimo. Srieginėms jung-tims, kurios patiria ašinių ciklinių apkrovų jau yra sukurtos modernesnės daugiaciklio ir mažaciklio ilgaamžiškumo skaičiavimo metodikos, kuriomis detaliai kiekybiškai įvertinamas ašinės apkrovos pasiskirstymas tarp vijų. Ap-krovos pasiskirstymo sriegyje kiekybiniai duomenys leidžia detaliau ir tiksliau įvertinti konstrukcijos ypatumų (jungties ilgio, medžiagos, veržlės ir vijų for-mos) ir jungties elementų deformavimo stadijų įtaką. Tokios ilgaamžiškumo skaičiavimo metodikos cikliškai lenkiamoms srieginėms jungtims netaikomos, nes lenkiamoms srieginėms jungtims nėra sukurtų apkrovos pasiskirstymo vijose analitinių modelių, tinkamų praktiniam naudojimui. Šioje srityje taip pat nėra sukurtų ir modelių, kurie skaičiuojami baigtinių elementų metodu. Kadangi srieginė jungtis yra kompleksinis mazgas, kurį sudaro deformuo-jami elementai, tai apkrovos pasiskirstymą tarp vijų lemia jungties elementų deformacijų ir poslinkių suderinamumas. Matematiškai aprašant jungties de-formuotą būvį, reikalingi teoriniai ir eksperimentiniai duomenys, kurie atspin-dėtų jungties elementų deformavimo specifinius ypatumus, pasireiškiančius veikiant lenkimui. Disertacijoje siekiama sukurti cikliškai lenkiamų srieginių jungčių apkro-vos pasiskirstymo sriegyje skaičiavimo metodą ir pritaikyti jį mažacikliam ilga-amžiškumui skaičiuoti.
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Utmaningen att bygga höga hus i Sverige : Hur utformning och byggnadslogistik utmanas av byggnadshöjdenDurakovic, Ahmet, Wang, Ken January 2019 (has links)
Because of increased domestic construction of taller buildings in Sweden during the lastdecade and more to be planned it is crucial to increase the knowledge in this field and analyzethe problems to find suitable solutions.Due to the nature of taller buildings it is important to focus on key areas that can affect theconstruction in its whole. Such as the logistics during the whole process from start to finishand more important the configurations of the building. This can include fire safety and theload from the wind.Through academic literatures and by interviewing people with key positions during theconstruction of tall buildings in Sweden we have gathered a foundation of information onhow to tackle the problems that occurring when constructing tall buildings.The aim of this degree project is to highlight the problems of the construction of tall buildingsand find suitable solutions of how to effectively minimize or solve the problems.
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Macroeconomic effects of fiscal policyYang, Weonho January 2013 (has links)
The interest in the use of fiscal policy as an effective economic policy tool has been revived recently, since the global recession of 2008 hit the world. In spite of a large empirical literature, there remains substantial uncertainty about the size and even the direction of the effects of discretionary fiscal policy. This thesis seeks to investigate the macroeconomic effects of discretionary fiscal policy in the short term, highlighting several methodologies for identifying discretionary fiscal policy. In Chapters 2 and 3, we suggest a new instrument based on the narrative approach for identifying exogenous government spending shocks: natural disaster damages and the subsequent government emergency spending. While applying our methodology to the Korean and the U.S data, we find that our instrument is not only powerful but also superior to military build-ups used by most of the literature. The relief expenditure in the wake of natural disaster has several advantages such as the similarity in scope to general government activity and the easy applicability beyond the U.S. compared to military build-ups. In the analysis of Korean fiscal policy, using our narrative method and the Structural Vector Autoregression (SVAR) model, we find that government spending shocks increase GDP, consumption, and real wage, which is in line with the New Keynesian model. We also find that the timing is crucial in identifying government spending shocks due to the anticipation effects of fiscal policy. Furthermore, while analyzing the U.S. fiscal policy both at the state as well as national level, we estimate two kinds of non-defense spending multipliers: federal (1.4~1.7) and state (1.5~2.5), which exceed the defense spending multiplier obtained in the literature using military building-ups. In Chapter 4, in regard to the study of effects of fiscal adjustment, we develop the approach based on changes in cyclically adjusted primary balance (CAPB) by including fluctuations of asset price in the CAPB measure and allowing for individual country heterogeneity in the definition of fiscal adjustment. Using our new CAPB in 20 OECD countries, we find that fiscal adjustments have contractionary effects on economic activity in the short term, which is consistent with the result based on the narrative approach. Nevertheless, our results suggest that fiscal adjustments that rely predominantly on spending cuts are less contractionary than those involving tax increases.
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Regla de Oro, sostenibilidad y regla fiscal contracíclica / Regla de Oro, sostenibilidad y regla fiscal contracíclicaJimenez, Félix 10 April 2018 (has links)
The current fiscal policy does not differentiate capital expenditure from current expenditure. Since the global deficit target is fixed according to the present fiscal policy rule, the non financial expenditure becomes pro cyclical, and the public investment is adjusted to meet the targeted deficit. As a result, the public investment has dramatically decreased which, in turn, has affected the international competitiveness and the economic and social development of the Peruvian society. This paper proposes: 1) change the public expenditure policy public investment by eliminating its pro cyclical bias; and 2) redefining the system of fiscal accounting. To meet this purposes the budget must be divided in two parts: the current budget with a saving or primary surplus target, and the investment expenditure based on a rule of directing the public debt only to finance this kind of expenditure over the economic cycle. This is the so called Public Investment Golden Rule. To this Golden Rule is added other according to which the ratio of public net debt must be sustainable during the economic cycle. Finally, it’s proposed to adopting the new IMF accounting system. The Golden Rule becomes pretty velar in the context of this new system. When the operational result becomes equal to cero, the net investment becomes equal to the public debt. Hence, the null operational result according to the new accounting system is the only one which is consistent with the Golden Rule. / La actual política fiscal no diferencia los gastos de capital de los gastos corrientes. La regla vigente de fijación de metas globales de déficit convierte al gasto no financiero en una variable procíclica, y la inversión pública es la que se ajusta para cumplir las metas de déficit. Esta política fiscal procíclica ha reducido la inversión pública a niveles mínimos sin precedentes históricos, conspirando así contra el desarrollo y la competitividad del país. En este trabajo se propone: 1) cambiar la política de gasto, eliminando el sesgo procíclico de la inversión pública; y 2) rediseñar la contabilidad fiscal. Para ello el presupuesto público debe dividirse en dos partes: uno de gasto corriente, con una meta de ahorro o de superávit primario corriente anual, y otro de gasto de inversión basado en una regla de destinar el endeudamiento, a lo largo del ciclo económico, a financiar solo el gasto de inversión y no el gasto corriente. Esta es la Regla de Oro de la Inversión pública. A esta regla se le adiciona otra según la cual la deuda neta del gobierno como porcentaje del PBI debe mantenerse, durante el ciclo económico, en un nivel sostenible. Asimismo, se plantea rediseñar la contabilidad fiscal sobre la base del nuevo sistema de contabilidad del FMI. Con este sistema, la Regla de Oro se hace aún más comprensible: cuando el resultado operativo es igual a cero, la inversión neta sería exactamente igual al endeudamiento. Por tanto, el único resultado coherente con la Regla de Oro en esta nueva contabilidad es que el ahorro corriente o resultado operativo sea nulo sobre el ciclo económico.
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Reconhecimento polinomial de álgebras cluster de tipo finito / Polynomial recognition of cluster algebras of finite typeDias, Elisângela SIlva 09 September 2015 (has links)
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Previous issue date: 2015-09-09 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / Cluster algebras form a class of commutative algebra, introduced at the beginning of the
millennium by Fomin and Zelevinsky. They are defined constructively from a set of generating
variables (cluster variables) grouped into overlapping subsets (clusters) of fixed
cardinality. Since its inception, the theory of cluster algebras found applications in many
areas of science, specially in mathematics. In this thesis, we study, with computational focus,
the recognition of cluster algebras of finite type. In 2006, Barot, Geiss and Zelevinsky
showed that a cluster algebra is of finite type whether the associated graph is cyclically
oriented, i.e., all chordless cycles of the graph are cyclically oriented, and whether the
skew-symmetrizable matrix associated has a positive quasi-Cartan companion. At first,
we studied the two topics independently. Related to the first part of the criteria, we developed
an algorithm that lists all chordless cycles (polynomial on the length of those
cycles) and another that checks whether a graph is cyclically oriented and, if so, list all
their chordless cycles (polynomial on the number of vertices). Related to the second part
of the criteria, we developed some theoretical results and we also developed a polynomial
algorithm that checks whether a quasi-Cartan companion matrix is positive. The latter
algorithm is used to prove that the problem of deciding whether a skew-symmetrizable
matrix has a positive quasi-Cartan companion for general graphs is in NP class. We conjecture
that this problem is in NP-complete class.We show that the same problem belongs
to the class of polynomial problems for cyclically oriented graphs and, finally, we show
that deciding whether a cluster algebra is of finite type also belongs to this class. / As álgebras cluster formam uma classe de álgebras comutativas introduzida no início
do milênio por Fomin e Zelevinsky. Elas são definidas de forma construtiva a partir de
um conjunto de variáveis geradoras (variáveis cluster) agrupadas em subconjuntos sobrepostos
(clusters) de cardinalidade fixa. Desde a sua criação, a teoria das álgebras cluster
encontrou aplicações em diversas áreas da matemática e afins. Nesta tese, estudamos,
com foco computacional, o reconhecimento das álgebras cluster de tipo finito. Em 2006,
Barot, Geiss e Zelevinsky mostraram que uma álgebra cluster é de tipo finito se o grafo
associado é ciclicamente orientado, isto é, todos os ciclos sem corda do grafo são ciclicamente
orientados, e se a matriz antissimetrizável associada possui uma companheira
quase-Cartan positiva. Em um primeiro momento, estudamos os dois tópicos de forma
independente. Em relação à primeira parte do critério, elaboramos um algoritmo que lista
todos os ciclos sem corda (polinomial no tamanho destes ciclos) e outro que verifica se
um grafo é ciclicamente orientado e, em caso positivo, lista todos os seus ciclos sem corda
(polinomial na quantidade de vértices). Relacionado à segunda parte do critério, desenvolvemos
alguns resultados teóricos e elaboramos um algoritmo polinomial que verifica
se uma matriz companheira quase-Cartan é positiva. Este último algoritmo é utilizado
para provar que o problema de decidir se uma matriz antissimetrizável tem uma companheira
quase-Cartan positiva para grafos gerais está na classe NP. Conjecturamos que
este problema pertence à classe NP-completa. Mostramos que o mesmo pertence à classe
de problemas polinomiais para grafos ciclicamente orientados e, por fim, mostramos que
decidir se uma álgebra cluster é de tipo finito também pertence a esta classe.
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Quelques développements combinatoires autour des groupes de Coxeter et des partitions d'entiers / Some combinatorial developpements about Coxeter Groups and integer partitionsPétréolle, Mathias 25 November 2015 (has links)
Cette thèse porte sur l'étude de la combinatoire énumérative, plus particulièrement autour des partitions d'entiers et des groupes de Coxeter. Dans une première partie, à l'instar de Han et de Nekrasov-Okounkov, nous étudions des développements combinatoires des puissances de la fonction êta de Dedekind, en termes de longueurs d'équerres de partitions d'entiers. Notre approche, bijective, utilise notamment les identités de Macdonald en types affines (en particulier le type C), généralisant l'approche de Han en type A. Nous étendons ensuite avec de nouveaux paramètres ces développements, grâce à de nouvelles propriétés de la décomposition de Littlewood vis-à-vis des partitions et statistiques considérées. Cela nous permet de déduire des formules des équerres symplectiques, ainsi qu'une connexion avec la théorie des représentations. Dans une seconde partie, nous étudions les éléments cycliquement pleinement commutatifs dans les groupes de Coxeter introduits par Boothby et al., qui forment une sous famille des éléments pleinement commutatifs. Nous commençons par développer une construction, la clôture cylindrique, donnant un cadre théorique qui est aux éléments CPC ce que les empilements de Viennot sont aux éléments PC. Nous donnons une caractérisation des éléments CPC en terme de clôtures cylindriques pour n'importe quel système de Coxeter. Celle-ci nous permet de déterminer en termes d'expressions réduites les éléments CPC dans tous les groupes de Coxeter finis ou affines, et d'en déduire dans tous ces groupes l'énumération de ces éléments. En utilisant la théorie des automates finis, nous montrons aussi que la série génératrice de ces éléments est une fraction rationnelle / This thesis focuses on enumerative combinatorics, particularly on integer partitions and Coxeter groups. In the first part, like Han and Nekrasov-Okounkov, we study the combinatorial expansion of power of the Dedekind's eta function, in terms of hook lengths of integer partitions. Our approach, bijective, use the Macdonald identities in affine types, generalizing the study of Han in the case of type A. We extend with new parameters the expansions that we obtained through new properties of the Littlewood decomposition. This enables us to deduce symplectic hook length formulas and a connexion with representation theory. In the second part, we study the cyclically fully commutative elements in Coxeter groups, introduced by Boothby et al., which are a sub family of the fully commutative elements. We start by introducing a new construction, the cylindrical closure, which give a theoretical framework for the CPC elements analogous to the Viennot's heaps for fully commutative elements. We give a characterization of CPC elements in terms of cylindrical closures in any Coxeter groups. This allows to deduce a characterization of these elements in terms of reduced decompositions in all finite and affine Coxeter and their enumerations in those groups. By using the theory of finite state automata, we show that the generating function of these elements is always rational, in all Coxeter groups
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Cross-Border Effects of Fiscal Policies / Přeshraniční dopady fiskálních politikMaleček, Petr January 2015 (has links)
This study seeks to analyse and quantify cross-border effects of discretionary fiscal policies from two major points of view. The aggregate approach rests on the use of the structural vector autoregression model (SVAR) and its extension, the global vector autoregression model (GVAR). The discretionary fiscal impulse itself is then defined as a change in cyclically adjusted balance of the government sector, calculated at quarterly frequencies. This section is then complemented by a case study of a single measure: the German car scrapping scheme during 2009 and its effects on the Czech economy. It was found that cross-border effects of discretionary fiscal policies may be indeed present, in case certain conditions are met. Importantly, a fiscal impulse has to originate from a sufficiently large economy and there needs to be a tight trade linkage between examined countries. In most cases, cross-border effects have also been found of lesser magnitude than direct impacts of fiscal policies on the domestic country. Finally, as demonstrated on the German-Czech case, even a single fiscal measure can trigger substantial cross-border spillovers. It was estimated that this measure positively contributed to real GDP growth in 2009 in the Czech Republic by 0.44 pp.
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Interactions between fiscal policy and real economy in the Czech Republic: a quantitative analysis / Kvantitativní analýza interakcí fiskální politiky a reálné ekonomiky v České republiceValenta, Vilém January 2004 (has links)
After many decades, macroeconomic effects of fiscal policy have returned to the centre of the economic policy debate. Both automatic fiscal stabilizers and discretionary fiscal stimuli have been used to support aggregate demand during the recent global economic crisis with a subsequent need for large-scale fiscal consolidations. In this context, a proper assessment of the size of automatic fiscal stabilizers and fiscal multipliers represents a key input for fiscal policymaking. This dissertation provides a quantitative analysis of the interactions between fiscal policy and real economy in the Czech Republic. The impact of real economy developments on public finances is assessed based on the methods of the OECD, the European Commission and the ESCB for the identification of general government structural balances, i.e. balances adjusted for effects of the economic cycle and net of one-off and other temporary transactions. I find that the underlying fiscal position, as approximated by the government structural balance, was mostly below the level stabilising the debt-to-GDP ratio since mid-1990s. An indistinct improvement in the structural balance can be identified in the period 2004--2007, which was subsequently reversed by the adverse structural impact of the world economic crisis. At the same time, dynamics of unadjusted fiscal balance was largely determined by one-off transactions in the past. The effects of fiscal policy on real economy are analysed using the structural VAR approach. I find that an increase in government spending has a temporary positive effect on output that peaks after one to two years with a multiplier of around 0.6. Tax multiplier appears to be small and, in contrast to standard Keynesian assumptions, positive. Government spending is supportive to private consumption, contradicting the hypothesis of Ricardian equivalence, but it crowds out private investment in the short run. The results should be interpreted with caution, as the analysis is complicated by rapidly changing economic environment in the period of the economic transition, relatively short available time series and a large number of one-off fiscal transactions.
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