In order to predict future range shifts for invasive species it is important to explore their ability to acclimate to the new environment and understand physiological and reproductive constraints controlling their distribution. My dissertation studied mechanisms by which temperature may affect the distribution of two of the most aggressive plant invaders in North America, Bromus tectorum and Bromus rubens. While Bromus tectorum is dominant in the “cold desert” steppes of the Intermountain region of western North America, B. rubens is one of the severe grass invaders in the “hot deserts” of southwestern North America. I first evaluated whether winter freezing tolerance is the mechanism responsible for the distinct northern range limits of Bromus species. Bromus rubens has a slower rate of freezing acclimation that leads to intolerance of sudden, late-autumn reductions in temperature below -12°C, Bromus tectorum, by contrast, cold hardens rapidly and is not impacted by the sudden severe late-autumn cold. Photosynthetic response to temperature does not explain their current range separation. Bromus species differ little in their photosynthetic temperature responses and the acclimation pattern of photosynthesis. Both species acclimated to a broad range of temperature through the amelioration of Pi regeneration limitation at sub-optimal temperatures and improved carboxylation capacity above the thermal optimum which probably resulted from increased thermostability of Rubisco activase. The effect of elevated temperatures during flowering on the seed yield of Bromus species demonstrates that neither species produces seed at 36°C and above. These thresholds are close to temperatures encountered during flowering in their natural environment. In summary, climatic changes will cause northward range expansion of Bromus species due to less severe autumn and winter, while reproductive failure could cause range contraction at their southern margins.

Diskriminacija dėl amžiaus yra viena iš opiausių diskriminacijos rūšių plačiai paplitusi darbo teisiniuose santykiuose. Nepaisant to, ši problema yra mažai išnagrinėta teisinėje literatūroje, o teismų išaiškinimų beveik nėra. Lietuvoje tik 2005 metais įsigaliojo specialusis Lygių galimybių įstatymas, skirtas užtikrinti darbuotojų lygias galimybes darbo sferoje nepaisant jų amžiaus, tačiau nuostatos yra gan abstrakčios ir neišbaigtos. Be to, ir pati visuomenė pasyviai reaguoja į diskriminaciją dėl amžiaus darbo sferoje ir dažnai netgi ją nuolankiai pateisina. Dėl to diskriminacija dėl amžiaus ir toliau egzistuoja faktiškai, sąlygodama darbo teisinių santykių dalyvių nelygias galimybes bei neigiamas ekonomines, socialines ir psichologines pasėkmes diskriminuojamų asmenų ir netgi valstybės atžvilgiu. Šis darbas išskiria dvi pagrindines neteisėtos diskriminacijos dėl amžiaus formas: tiesioginę ir netiesioginę. Tiesioginė diskriminacija suvokiama kaip sąmoningas skirtingų įdarbinimo arba atleidimo iš darbo sąlygų sudarymas darbuotojams dėl jų amžiaus. Tai suponuoja draudimą darbdaviams darbo skelbimuose nurodyti pageidaujamo pretendentų amžiaus ribas, dėl ko skirtingo amžiaus asmenys yra iš anksto diskvalifikuojami dėl savo asmeninių, o ne dalykinių savybių. Tiesioginė diskriminacija apima ir tokius atvejus, kai darbdavys savo sprendimą atsisakyti sukurti darbo teisinius santykius arba juos nutraukti su tam tikro amžiaus darbuotojais grindžia ne objektyviomis... [toliau žr. visą tekstą] / Labor relationship is based on the principle of equality that outlaws the discimination of labour law subjects on the ground of their age in any stage of employment, including recruitment and dismissal, which are the focal stages of this paper. Despite this formal declaration of equality, factual instances of age discrimination are widespread and have a tendency to grow, as a result of which the constitutional right to work is violated and human dignity is injured. Considering this, the European Council promulgated Directive 2000/78/EB to tackle the issue of age discrimination in employment and occupation particularly. Being responsible for the implementation of the Directive, the Republic of Lithuania issued a special Equal Opportunities Law, which came into effect as of 1 January 2005. In spite of the legal basis, there is almost no case law on age discrimination and only a few scholarly researches have been done in this field, therefore the problem of age discrimination remains poorly explored and existing in practice. In general, national laws protect employees/public officials against direct and indirect age discrimination upon recruitment and dismissal. Direct discrimination refers to the situation where an employee/public official is not employed or is dismissed only because of his/her age. It covers not only employer’s expressive indication of a preferable age for work (esp. typical to job offers) but also the reliance on factors directly linked to age... [to full text]

The Dissertation covers the aspect of term limits of head of state and its links with the principles of national sovereignty, separation of powers and supremacy of the constitution in various forms of state government. The analysis of the concept of powers and term limits of head of state, put into the context of development of the global legal thought, uncovers progress in the scientific understanding of the concept and paves the way to the key arguments of the Paper (the right to establish term limits of authorities lies with the nation (John Locke); the term limit of authority is inversely proportional to the greatness of power (Charles Montesquieu). The study into the features and dynamics of constitutional regulation of term limits of head of state is based on the analysis of the relevant provisions in over 500 constitutions; as a result, the study establishes the development trends in the definition of term limits enshrined in the said constitutions. Another part of the study looks into the reasons behind the violations of constitutional provisions on term limits of head of state and analyses the dynamics of the said violations in monarchies and republics as forms of government, paying attention to the criterion of greatness of authority of head of state. On the basis of the present research, the author establishes the effectiveness of direct and inverse application of the rule formulated by Charles Montesquieu (the greatness of power must be compensated by the brevity... [to full text] / Disertacijoje atskleistas valstybės vadovo įgaliojimų trukmės aspektas ir jo sąsajos su Tautos suvereniteto, valdžių padalijimo, Konstitucijos viršenybės principais valstybės valdymo formose. Analizuojant valdžios ir valstybės vadovo įgaliojimų trukmės sampratą pasaulio teisinės minties raidoje, nustatytas jos mokslinio suvokimo progresas ir esminiai konstatuojamieji teiginiai (teisė nustatyti valdžios įgaliojimų trukmę priklauso tautai (J. Locke), valdžios įgaliojimų trukmė atvirkščiai proporcinga įgaliojimų dydžiui (Sh. Montesquieu). Tiriant valstybės vadovo įgaliojimų trukmės konstitucinio reguliavimo ypatumus ir dinamiką, išnagrinėtos ir apibendrintos daugiau nei 500 konstitucijų aktualios nuostatos, nustatytos jose užfiksuotų įgaliojimų trukmių apibrėžimų raidos tendencijos. Kitame tyrime nagrinėtos valstybės vadovo įgaliojimų trukmės konstitucinių nuostatų pažeidimų priežastys, dinamika monarchijos bei respublikos valdymo formose, atsižvelgiant į vadovų įgaliojimų apimties kriterijų. Remiantis tyrimų duomenimis, nustatytas Sh. Montesquieu teiginio (kuo valdžios įgaliojimai didesni, tuo trumpiau ji turi valdyti) tiesioginio ir atvirkštinio taikymo efektyvumas. Patvirtinta mokslinio tyrimo prielaida, jog valstybės vadovo įgaliojimų trukmės konstitucinių nuostatų pažeidžiamumas yra proporcingas jo įgaliojimų apimčiai. Šią konstitucinio reguliavimo problemą siūloma spręsti naudojant atvirkštinį Sh.Montesquieu teiginį (kuo valdžios įgaliojimai menkesni, tuo jų trukmė yra... [toliau žr. visą tekstą]

This dissertation investigates the impacts of constraints on optimal government policy. The first two chapters provide a general introduction and review of the literature. Chapters three and four analyze education spending and institutional structure in an economy with informational asymmetries and employment matching frictions. The fifth investigates the impact of politics on government decisions over taxation and spending programs more generally. Chapter three analyzes the situation where governments can target education funds to specific observable groups (referred to as low and high productivity neighbourhoods/regions). The results suggest that it may be optimal to employ educational transfers, rather than cash transfers amongst individuals, to achieve social welfare objectives. This is becasue the former can reduce distortions created by the tax system. However, the value of educational spending in mitigating these information frictions may not be that large, and may in fact exacerbate such distortions. This suggests that an optimal education policy may be more regressive when there is a distortionary tax system in place. Further, we showt that even if ``equalizing opportunities'' is deemed optimal in the static problem, it may not be a reasonable policy goal when we extend the analysis to include dynamics. Chapter four is joint work with Afrasiab Mirza. We analyze an economy where heterogeneous individuals are uncertain about their endowments. The education system trades off the desire to capitalize on talent through specific skills training with the need to provide individuals with opportunities to learn about their career preferences through a broader education. The results consider the implications of various educational institutions for the income distribution and consequently welfare. Chapter five analyzes the dynamics of public spending, taxation and debt in a political agency model. Choices are made by short-lived politicians who can be only partially controlled through the electoral process. The main focus is to consider the impacts of binding limits on the public budget. The value of imposing this additional friction depends both on the extent to which politicians' goals deviate from their constituencies and how effectively the electoral process disciplines them when they misbehave. The results also suggest that the value of such a restriction depends on the fiscal position at the time in which it is imposed. / Thesis (Ph.D, Economics) -- Queen's University, 2009-11-25 20:25:29.12

This thesis presents an investigation into the power transmission limitations imposed on a VSC-HVdc converter by ac system strength and ac system impedance characteristics, quantified by the short circuit ratio (SCR). An important result of this study is that the operation of the converter is not only affected by the SCR’s magnitude, but is also significantly affected by the ac system’s impedance angle at the fundamental frequency. As the ac impedance becomes more resistive, the minimum SCR required at the rectifier side increases from that required for ideally inductive ac impedance, but it decreases at the inverter side. The finite megavolt ampere (MVA) limit of the VSC imposes a further limitation on power transfer, requiring an increase in the value of the minimum SCR. This limitation can be mitigated if additional reactive power support is provided at the point-common-connection. A state-space VSC model was developed and validated with a fully detailed non-linear EMT model. The model showed that gains of the phased-locked-loop (PLL), particularly at low SCRs greatly affect the operation of the VSC-HVdc converter and that operation at low SCRs below about 1.6 is difficult. The model also shows that the theoretically calculated power-voltage stability limit is not attainable in practice, but can be approached if the PLL gains are reduced. The thesis shows that as the VSC-HVdc converter is subject to large signal excitation, a good controller design cannot rely on small signal analysis alone. The thesis therefore proposes the application of optimization tools to coordinate the controls of multiple converters in a dc grid. A new method, the "single converter relaxation method", is proposed and validated. The design procedure of control gains selection using the single converter relaxation method for a multi-converter system is developed. A new method for selecting robust control gains to permit operation over a range of operation conditions is presented. The coordination and interaction of control parameters of multi-terminal VSC are discussed. Using the SCR information at converter bus, the gain scheduling approach to optimal gains is possible. However, compared to robust control gains setting, this approach is more susceptible to system instability.

Visuomenėje kylančios diskusijos dėl didelio mokesčių lygio yra aktualios ir palydimos daugybės komentarų. Mokesčių lygio svarstymas apima teisines, politines ir ekonomikos sritis. Šio darbo problema yra ta, kad Vyriausybei vykdant mokestinę politiką visuomenėje išnyksta teisinis tikrumas dėl buvimo apribojimų, kurie varžytų maksimalios mokestinės naštos ribą. Šiam darbui keliami tokie uždaviniai: (1) atskleisti mokestinės prievolės esmę; (2) nustatyti mokestinei prievolei atsirasti būtinas prielaidas; (3) nustatyti mokestinės prievolės nebuvimo prielaidas; (4) pagrįsti teisinės valstybės finansavimo mokesčiais būtinumą; (5) išnagrinėti mokestinės naštos didinimo istorinius atvejus; (6) išskirti ir apibūdinti laikotarpius, kuomet mokestinės naštos didinimui galioja mažesni apribojimai; (7) išanalizuoti situacijas Lietuvos Respublikoje mokesčių reguliavimo politikoje ir teisės aktuose, kuomet galėtų būti maksimaliai didinama mokestinės naštos riba. Šio darbo tikslas yra ištirti mokestinės naštos didinimo teisėtumą. Šio darbo objektas – maksimalios mokestinės naštos ribos. Įgyvendinant darbo tikslą, daugiausia dėmesio buvo skiriama mokestinės prievolės atskleidimui, mokestinės prievolės pagrindimui ir maksimalios mokestinės naštos ribų ieškojimui ir jų teisėtumo tyrimui. Šis iškeltas tikslas darbe sėkmingai įgyvendintas – išanalizavus mokesčių teisės literatūrą, politines – teisines teorijas ir mokestinės naštos reguliavimo teorinius aspektus bei praktiką. Vadovaujantis įvairių... [toliau žr. visą tekstą] / The title of this work is: Is it legitimate to impose 100 % personal income tax? The tackled problem in this work is that as the Government creates new tax policy it also creates some uncertainty in the society because of vagueness of legal limitations to impose maximum tax burden. It creates a lot of discussion in society as people on micro economical level very vulnerable to Government’s moves in changing tax policy. The actuality of this problem is that after 2008 global financial crisis the interest in society towards economical issues skyrocketed into unseen level and internet news sites were bombarded by differently economically educated people. Indeed, the changes in tax policy touches almost every person‘s life and there is proverbial Benjamin Franklin saying that „in this world nothing can be said to be certain, except death and taxes“. The stability of tax policy for businesses and investors is of most importance when choosing country to invest and the acts of Government witnesses about its readiness to keep promises by creating long term stable legal business environment. In country, where is „rule of law“, one thing to evaluate the Government decision to raise tax level is to question its legitimacy. Every such decision to change tax policy should be grounded in specific needs and situations. The problem is not with individual tax but with general tax level. The finding of maximum level of taxation would give more clarity to state and it‘s citizen relationship as... [to full text]

Some of the most important work in the development of economic theory is associated with the study of market structure. In essence, most markets are two-sided. For example, product markets connect tens of thousands of product brands to tens of millions of consumers; marriage markets couple the single men and women who would otherwise suffer from a lonely heart; and labour markets link the job candidates to their preferred employers and positions. Apart from the two-sidedness, we have explored another important common aspect of these market structures, i.e. interconnection/competition of the segments within one side of the market. Under this common thread, the three essays in this thesis are freshly formulated in a loosely related manner, covering topics in three different areas. Chapter 2 is motivated by strategic transitions of many marketplaces (e.g. Amazon.com). From the perspective of a platform owner, when it owns part of the business on one side of the market, there is no straightforward answer as to whether having the rest of business owned by others is advantageous or not. The argument is that, on the one hand, the platform welcomes more third-party business as it boosts revenue in terms of membership fees; on the other hand the business owned by the platform dislikes the incoming competitors whose participation drives down pro t margins. We propose a novel framework in this chapter to explore the trade-off between the two. Here, the intermediary can decide to be either a "merchant" or a "two-sided platform", or a hybrid one in between. Our analysis shows that in hybrid mode the platform extracts all the surplus from the producers of the merchandised brands, and the merchandised brands always charge a price premium compared to the directly retailed ones. We also show that as the platform absorbs an existing directly retailed brand into the self-brand portfolio, the equilibrium prices of both brand types are increased. We find that only the directly retailed brands dominate the market when the platform s capacity is relatively small; and both brand types coexist in the marketplace when the capacity is relatively large. Furthermore, we find a backward bending proportion plus a vertical proportion of the "contract curve" in comparative statics. That is, the self-brand portfolio always expands while the third-party-brand portfolio shrinks until it reaches a certain level, when the platform increases its capacity. It helps us to gain some ideas on the dynamics of brand portfolio management for the platform. Lastly, taking into account of indirect network effect which is the common feature in the two-sided market, it is shown that the platform is better o¤ when consumers have positive expected surplus. Chapter 3 is much motivated by the Chinese experience. China has witnessed the largest rural to urban labour ow (among which the majority are male) in the world s history over the last three decades. We propose an idea that the grand migration can also be attributed to the unbalanced sex ratio between rural and urban areas. This chapter develops a two-sided matching model of two linked marriage markets with homogeneous agents, non-transferable utility and search friction. We extend the one-market model of the previous literature into a two-market one, allowing the agents to migrate between the markets at a fixed cost. The analysis focuses on the unmatched as well as the migrating population, which is induced by the different sex ratios in the two geographically isolated marriage markets. We find that imperfections in the matching technology leads to the enlarged gap of sex ratio of the unmatched population compared to that of the unbalanced inflows. We are interested in the question of how the migrating costs affect the migration between rural and urban areas, and under what conditions a subsidy covering migrating costs might benefit a party in the marriage markets. We characterise the equilibrium set in the parameter space of migrating costs, and find that a full subsidy of migrating costs does not necessarily benefit those who receive it but always benefits the opposite sex, if they are the short sides of both markets. Chapter 4 explains the migration of labour force from a different angle. Here, the migration is of workers to jobs. Motivated by the distinction of public and private sector, we consider a spatial oligopsony model in which forms (two co-locating small firms with recruiting capacity constraints and a large firm without such limit) are competing for workers along a "strip" market. The capacity issue that is extensively discussed in the Chapter 2 again plays an important role in this model, though in a very different context. It is shown that the recruiting capacity affects the intra-group competition and hence the inter-group competition in wage- posting strategies. Additionally, we show that, as recruiting limits expand, the expected wages offered by the small firms increase while the wage offered by the big firm decreases, which helps to explain the recent trend of the wage disparity between public and private jobs. We also characterise the equilibrium wages and the size (direction) of the migration in the three-stage game (i.e. the workers decide whether to relocate in the first stage, then the big firm decides its wage offer, and lastly, the two co-locating firms simultaneous set wages), which helps us to understand better the inter-sector mobility in a changing environment of economy. We investigate the issues of interconnection and competition in three different markets. It is always of interest for a researcher of economics to have some ideas on the same issue from different perspectives. Remember that whilst this is a collection of essays on economic theory, it is nonetheless compared to empirical observation. And it will surely serve as a starting point for the author to further the research on market structure.

The American Association of Highway and Transportation Officials (AASHTO) and Federal Highway Administration (FHWA) require the use of the statistically based quality assurance (QA) specifications for construction materials. As a result, many of the state highway agencies (SHAs) have implemented the use of a QA specification for highway construction. For these statistically based QA specifications, quality characteristics of most construction materials are assumed normally distributed, however, the normality assumption can be violated in several forms. Distribution of data can be skewed, kurtosis induced, or bimodal. If the process shows evidence of a significant departure from normality, then the quality measures calculated may be erroneous. In this research study, an extended QA data analysis model is proposed which will significantly improve the Type I error and power of the F-test and t-test, and remove bias estimates of Percent within Limit (PWL) based pay factor calculation. For the F-test, three alternative tests are proposed when sampling distribution is non-normal. These are: 1) Levene’s test; 2) Brown and Forsythe’s test; and 3) O’Brien’s test. One alternative method is proposed for the t-test, which is the non-parametric Wilcoxon - Mann – Whitney Sign Rank test. For PWL based pay factor calculation when lot data suffer non-normality, three schemes were investigated, which are: 1) simple transformation methods, 2) The Clements method, and 3) Modified Box-Cox transformation using “Golden Section Search” method. The Monte Carlo simulation study revealed that both Levene’s test and Brown and Forsythe’s test are robust alternative tests of variances when underlying sample population distribution is non-normal. Between the t-test and Wilcoxon test, the t-test was found significantly robust even when sample population distribution was severely non-normal. Among the data transformation for PWL based pay factor, the modified Box-Cox transformation using the golden section search method was found to be the most effective in minimizing or removing pay bias. Field QA data was analyzed to validate the model and a Microsoft® Excel macro based software is developed, which can adjust any pay consequences due to non-normality.

The increasing demand for powerful miniaturized products for all industrial applications has prompted the industry to develop new and innovative manufacturing processes to fabricate miniature parts. One of the major challenges facing the industry is the dynamic market which requires continuous improvements in design and fabrication techniques. This means providing products with complex features while sustaining high functionality. As a result, microfabrication has gained a wide interest as the technology of the future, where tabletop machine systems exist. Microforming processes have the capability of achieving mass production while minimizing material waste. Microforming techniques can produce net-shape products with intricacy in fewer steps than most conventional microfabrication processes. Despite the potential advantages, the industrial utilization of microforming technology is limited. The deformation and failure modes of materials during microforming is not yet well understood and varies significantly from the behavior of materials in conventional forming operations. In order to advance the microforming technology and enable the effective fabrication of microparts, more studies on the deformation and failure of materials during microforming are needed. In this research work, an effort to advance the current status of microforming processes for technologies of modern day essentials, is presented. The main contribution from this research is the development of a novel method for characterizing thin sheet formability by introducing a micro-mechanical bulge-forming setup. Various aspects of analyzing microscale formability, in the form of limiting strains and applied forces, along with addressing the well known size effects on miniaturization, were considered through the newly developed method. A high temperature testing method of microformed thin sheets was also developed. The aim of high temperature microforming is to study the material behavior of microformed thin sheets at elevated temperatures and to explore the capability of the known enhancement in formability at the macroscale level. The focus of this work was to develop a better understanding of tool-sheet metal interactions in microforming applications. This new knowledge would provide a predictive capability that will eliminate the current time-consuming and empirical techniques that, and this in turn would be expected to significantly lower the overall manufacturing cost and improve product quality.

Submitted in partial compliance with the requirements for the Master of Technology: Chiropractic, Durban University of Technology, 2014. / Background: Poor balance is a risk factor for injury in adolescent sport including soccer. Despite the rapid growth in female adolescent soccer especially in South Africa, the association between balance and injury in this population has not been fully explored. This study aimed to determine the relationship between injury and balance. Static and dynamic balance was monitored as sway index (SI) and limits of stability direction control (LOSDC). Objectives: The objectives of this study were to determine the body mass index of adolescent female soccer players; to determine the prevalence of injury in adolescent female soccer players; to determine static balance as revealed by the sway index (SI); to determine dynamic stability as revealed by limits of stability direction control (LOSDC) and to correlate body mass index (BMI) to sway index and limits of stability. Method: Eighty adolescent female soccer players, between the ages of fourteen and eighteen, were recruited through convenience sampling from schools in the eThekwini district of KwaZulu-Natal. After obtaining informed consent and assent, participants completed questionnaires and were scheduled for the balance and BMI assessments. The objective data for each participant consisted of height, weight, Sway Index (SI) and Limits of Stability Direction Control (LOSDC) readings, measured using a stadiometer, electronic scale and Biodex Biosway Balance System (Biodex Medical Systems Inc., Shirley, New York) respectively. The subjective and objective data were analyzed using SPSS version 21.0 (SPSS Inc. Chicago, Ill, USA). Statistical tests included descriptive statistics using frequency and cross-tabulation. Inferential statistics using t-tests and Pearson’s correlations at a significance level of 0.05 was also incorporated. The testing of hypotheses was performed using Fisher’s Exact tests for nominal data and ordinal data. A p value of < 0.05 was considered as statistically significant. The statistical analysis also included Odds Ratio calculations. Results: The mean body mass index of the injured participants was 23.54±3.56 kg/m2 and the mean body mass index of the uninjured participants was 23.00±4.63. Only 27.5% of the participants sustained an injury. Injured participants performed poorly on average in the SI assessment involving their eyes open when standing on a soft surface. The results were similar for the LOSDC in the overall, right, left, backward-right and backward-left directions. However, there were no significant correlations calculated. Significant relationships existed between BMI and the SI assessments in the injured participants which involved standing on a firm surface with their eyes open (p = 0.05), their eyes closed when also standing on a firm surface (p = 0.05), their eyes open when standing on a soft surface (p = 0.02), and their eyes closed when standing on a soft surface (p = 0.04). A significant relationship also existed between BMI and LOS right direction control (p = 0.02). Conclusion: This research paper revealed that the body mass index as investigated in this study is similar to other studies involving female adolescents; soccer injury as investigated in this study is similar to other studies involving female adolescents; poor static and dynamic balance is not associated with injury in adolescent female soccer players and lastly, body mass index is linked to the balance of an individual.