840 resultados para Economics, Mathematical.
Resumo:
Using an OLG-model with endogenous growth and public capital we show, that an international capital tax competition leads to inefficiently low tax rates, and as a consequence to lower welfare levels and growth rates. Each national government has an incentive to reduce the capital income tax rates in its effort to ensure that this policy measure increases the domestic private capital stock, domestic income and domestic economic growth. This effort is justified as long as only one country applies this policy. However, if all countries follow this path then all of them will be made worse off in the long run.
Resumo:
This paper empirically examines the effect of current tax policy on home ownership, specifically looking at how developer contributions impact house prices. Developer contributions are a commonly used mechanism for local governments to pay for new urban infrastructure. This research applies a hedonic house price model to 4,699 new and 25,053 existing house sales in Brisbane from 2005 to 2011. The findings of is research are consistent with international studies that support the proposition that developer contributions are over passed. This study has provided evidence that suggest developer contributions are over passed to both new and existing homes in the order of around 400%. These findings suggest that developer contributions are thus a significant contributor to increasing house prices, reduced housing supply and are thus an inefficient and inequitable tax. By testing this effect on both new and existing homes, this research provides evidence in support of the proposition that not only are developer contributions over passed to new home buyers but also to buyers of existing homes. Thus the price inflationary effect of these developer contributions are being felt by all home buyers across the community, resulting in increased mortgage repayments of close to $1,000 per month in Australia. This is the first study to empirically examine the impact of developer contributions on house prices in Australia. These results are important as they inform governments on the outcomes of current tax policy on home ownership, providing the first evidence of its kind in Australia. This is an important contribution to the tax reform agenda in Australia.
Resumo:
This submission addresses the problem of housing price inflation, the chronic under-supply of new housing stock, and the resultant decline in housing affordability for low and middle income households. It specifically focusses on the supply of medium density housing (multi-unit development) in Melbourne, although we believe that the observations made about housing in supply in Melbourne are relevant in other urban centres and to other types of housing supply. In terms of medium density housing (MDH) our concern also extends to the poor quality and design. Why the market tends to deliver generic apartments of poor quality and design which are uncompetitive with lower density housing and amenity despite planning objectives, and how this apparently intractable problem can be overcome is the topic of this submission...
Resumo:
Analytical techniques for measuring and planning railway capacity expansion activities have been considered in this article. A preliminary mathematical framework involving track duplication and section sub divisions is proposed for this task. In railways these features have a great effect on network performance and for this reason they have been considered. Additional motivations have also arisen from the limitations of prior models that have not included them.
Resumo:
This article focusses upon multi-modal transportation systems (MMTS) and the issues surrounding the determination of system capacity. For that purpose a multi-objective framework is advocated that integrates all the different modes and many different competing capacity objectives. This framework is analytical in nature and facilitates a variety of capacity querying and capacity expansion planning.
Resumo:
Reduced economic circumstances havemoved management goals towards higher profit, rather than maximum sustainable yields in several Australian fisheries. The eastern king prawn is one such fishery, for which we have developed new methodology for stock dynamics, calculation of model-based and data-based reference points and management strategy evaluation. The fishery is notable for the northward movement of prawns in eastern Australian waters, from the State jurisdiction of New South Wales to that of Queensland, as they grow to spawning size, so that vessels fishing in the northern deeper waters harvest more large prawns. Bioeconomic fishing data were standardized for calibrating a length-structured spatial operating model. Model simulations identified that reduced boat numbers and fishing effort could improve profitability while retaining viable fishing in each jurisdiction. Simulations also identified catch rate levels that were effective for monitoring in simple within-year effort-control rules. However, favourable performance of catch rate indicators was achieved only when a meaningful upper limit was placed on total allowed fishing effort. Themethods and findings will allow improved measures for monitoring fisheries and inform decision makers on the uncertainty and assumptions affecting economic indicators.
Resumo:
Discharge periods of lead-acid batteries are significantly reduced at subzero centigrade temperatures. The reduction is more than what can he expected due to decreased rates of various processes caused by a lowering of temperature and occurs despite the fact that active materials are available for discharge. It is proposed that the major cause for this is the freezing of the electrolyte. The concentration of acid decreases during battery discharge with a consequent increase in the freezing temperature. A battery freezes when the discharge temperature falls below the freezing temperature. A mathematical model is developed for conditions where charge-transfer reaction is the rate-limiting step. and Tafel kinetics are applicable. It is argued that freezing begins from the midplanes of electrodes and proceeds toward the reservoir in-between. Ionic conduction stops when one of the electrodes freezes fully and the time taken to reach that point, namely the discharge period, is calculated. The predictions of the model compare well to observations made at low current density (C/5) and at -20 and -40 degrees C. At higher current densities, however, diffusional resistances become important and a more complicated moving boundary problem needs to be solved to predict the discharge periods. (C) 2009 The Electrochemical Society.
Resumo:
Models that implement the bio-physical components of agro-ecosystems are ideally suited for exploring sustainability issues in cropping systems. Sustainability may be represented as a number of objectives to be maximised or minimised. However, the full decision space of these objectives is usually very large and simplifications are necessary to safeguard computational feasibility. Different optimisation approaches have been proposed in the literature, usually based on mathematical programming techniques. Here, we present a search approach based on a multiobjective evaluation technique within an evolutionary algorithm (EA), linked to the APSIM cropping systems model. A simple case study addressing crop choice and sowing rules in North-East Australian cropping systems is used to illustrate the methodology. Sustainability of these systems is evaluated in terms of economic performance and resource use. Due to the limited size of this sample problem, the quality of the EA optimisation can be assessed by comparison to the full problem domain. Results demonstrate that the EA procedure, parameterised with generic parameters from the literature, converges to a useable solution set within a reasonable amount of time. Frontier ‘‘peels’’ or Pareto-optimal solutions as described by the multiobjective evaluation procedure provide useful information for discussion on trade-offs between conflicting objectives.
Resumo:
The aim of this dissertation is to provide conceptual tools for the social scientist for clarifying, evaluating and comparing explanations of social phenomena based on formal mathematical models. The focus is on relatively simple theoretical models and simulations, not statistical models. These studies apply a theory of explanation according to which explanation is about tracing objective relations of dependence, knowledge of which enables answers to contrastive why and how-questions. This theory is developed further by delineating criteria for evaluating competing explanations and by applying the theory to social scientific modelling practices and to the key concepts of equilibrium and mechanism. The dissertation is comprised of an introductory essay and six published original research articles. The main theses about model-based explanations in the social sciences argued for in the articles are the following. 1) The concept of explanatory power, often used to argue for the superiority of one explanation over another, compasses five dimensions which are partially independent and involve some systematic trade-offs. 2) All equilibrium explanations do not causally explain the obtaining of the end equilibrium state with the multiple possible initial states. Instead, they often constitutively explain the macro property of the system with the micro properties of the parts (together with their organization). 3) There is an important ambivalence in the concept mechanism used in many model-based explanations and this difference corresponds to a difference between two alternative research heuristics. 4) Whether unrealistic assumptions in a model (such as a rational choice model) are detrimental to an explanation provided by the model depends on whether the representation of the explanatory dependency in the model is itself dependent on the particular unrealistic assumptions. Thus evaluating whether a literally false assumption in a model is problematic requires specifying exactly what is supposed to be explained and by what. 5) The question of whether an explanatory relationship depends on particular false assumptions can be explored with the process of derivational robustness analysis and the importance of robustness analysis accounts for some of the puzzling features of the tradition of model-building in economics. 6) The fact that economists have been relatively reluctant to use true agent-based simulations to formulate explanations can partially be explained by the specific ideal of scientific understanding implicit in the practise of orthodox economics.
Resumo:
A mathematical model for pulsatile flow in a partially occluded tube is presented. The problem has applications in studying the effects of blood flow characteristics on atherosclerotic development. The model brings out the importance of the pulsatility of blood flow on separation and the stress distribution. The results obtained show fairly good agreement with the available experimental results.
Resumo:
This thesis concerns the development of mathematical models to describe the interactions that occur between spray droplets and leaves. Models are presented that not only provide a contribution to mathematical knowledge in the field of fluid dynamics, but are also of utility within the agrichemical industry. The thesis is presented in two parts. First, thin film models are implemented with efficient numerical schemes in order to simulate droplets on virtual leaf surfaces. Then the interception event is considered, whereby energy balance techniques are employed to instantaneously predict whether an impacting droplet will bounce, splash, or adhere to a leaf.
Resumo:
Given the growing importance of the Chinese tourist market to Australia, an understanding of Chinese tourists' arrival patterns is essential to accurate forecasting of future arrivals. Drawing on 25 years of records (1991-2015), this study developed a time-series model of monthly arrivals of Chinese tourists in Australia. The model reflects the exponentially increasing trend and strong seasonality of arrivals. Excellent results from validation of the model's forecasts endorsed this time-series model's potential in the policy prescription and management practice of Australian tourism industries.
Resumo:
Continuous growth in the number of immigrant students has changed the Finnish school environment. The resulting multicultural school environment is new for both teachers and students. In order to develop multicultural learning environments, there is a need to understand immigrant students everyday lives in school. In this study, home economics is seen as a fruitful school subject area for understanding these immigrant students lives as they cope with school and home cultures that may be very different from each other. Home economics includes a great deal of knowledge and skills that immigrant students need during their everyday activities outside of school. -- The main aim of the study is to clarify the characteristics of multicultural home economics classroom practices and the multicultural contacts and interaction that take place between the students and the teacher. The study includes four parts. The first part, an ethnographical prestudy, aims to understand the challenges of multicultural schoolwork with the aid of ethnographical fieldwork done in one multicultural school. The second part outlines the theoretical frames of the study and focuses on the sociocultural approach. The third part of the study presents an analysis of videodata collected in a multicultural home economics classroom. The teacher s and students interaction in the home economics classroom is analyzed through the concepts of the sociocultural approach and the cultural-historical activity theory. Firstly, this is done by analyzing the focusedness of the teacher s and the students actions as well as the questions presented and apparent disturbances during classroom interaction. Secondly, the immigrant students everyday experiences and cultural background are examined as they appear during discussions in the home economics lessons. Thirdly, the teacher s tool-use and actions as a human mediator are clarified during interaction in the classroom. The fourth part presents the results, according to which a practice-based approach in the multicultural classroom situation is a prerequisite for the teacher s and the students shared object during classroom interaction. Also, the practice-based approach facilitates students understanding during teaching and learning situations. Practice in this study is understood as collaborative teaching and learning situations that include 1) guided activating learning, 2) establishing connections with students everyday lives and 3) multiple tool-use. Guided activating learning in the classroom is defined as situations that occur and assignments that are done with a knowledgeable adult or peer and include action. The teacher s demonstrations during the practical part of the lessons seemed to be fruitful in the teaching and learning situations in the multicultural classroom. Establishing connections with students everyday lives motivated students to follow the lesson and supported understanding of meaning. Furthermore, if multiple tools (both psychological and material) were used, the students managed better with new and sometimes difficult concepts and different working habits, and accomplished the practical work more smoothly . The teacher s tool-use and role as a mediator of meaning are also highlighted in the data analysis. Hopefully, this study can provide a seedbed for situations in which knowledge produced together, as well as horizontally oriented tool-use, can make school-learned knowledge more relevant to immigrant students everyday lives, and help students to better cope with both classroom work and outside activities. KEY WORDS: home economics education, multicultural education, sociocultural perspective, classroom interaction, videoanalysis
Resumo:
This project investigated the calcium distributions of the skin, and the growth patterns of skin substitutes grown in the laboratory, using mathematical models. The research found that the calcium distribution in the upper layer of the skin is controlled by three different mechanisms, not one as previously thought. The research also suggests that tight junctions, which are adhesions between neighbouring skin cells, cannot be solely responsible for the differences in the growth patterns of skin substitutes and normal skin.