2,712 research outputs found

    The urban component of the energy crisis

    Get PDF
    The spiral of higher oil prices that is occurring currently is mostly caused not by the lack of reserves, but by increasing demand on the existing supply. However, increase of supply would only temporarily attenuate the issue, as demand is expected to continue to soar and eventually outstrip the reserves of fossil fuels, which combined account of almost all our present energy sources. It is not that fossil fuels will disappear, but rather the certainty that they will become progressively scarcer and definitely more expensive as time goes by, has become an irreversible and well established trend. The cost increase of a critical resource - energy - will force unforeseen changes in production and in distribution of goods, affecting the whole productive matrix - including employment. Not only new products and distribution systems based on higher energy costs will need to be conceived and implemented but especially the current reliance on fossil fuels - oil, gas and coal - will need to be replaced almost entirely by sustainable sources - an extraordinarily complex enterprise that should consume our efforts in the next 40 years. Energy consumption will be further aggravated by the expected 2.3 billion population increase from now to 2050, which is expected to be almost entirely concentrated in the urban centres of Asia, Latin America and Africa. Since these additional urban spaces are still to be developed, urban development strategies that consider higher energy costs could effectively alleviate the transition period from fossil fuels to sustainable sources. Rather than providing a recipe for urban planning, this paper stresses the need for further research to incorporate the energy cost component with the urban development context and the dissemination of information on this matter.energy; environment; urban; development; planning;

    South Sudan urban development strategy

    Get PDF
    Southern Sudan - the ten southern provinces of Sudan - has attained autonomy and may soon achieve total independence from Sudan. Yet decades of civil war not only prevented development but destroyed the infrastructure left over from the colonial period. While Southern Sudan is fortunate to have oil resources that can finance building up the new nation, the task is enormous - there are no cities, there is no established industrial base, there are no means of transport, agriculture is incipient and cattle raising still follows ancient nomadic traditions. To aggravate the situation, millions of returning refugees and internally displaced persons are returning to their homelands and need to be settled. This paper, by outlining a simple, pragmatic strategy to setup the 10 state capitals, is a response to the effort of the Government of Southern Sudan (GOSS) in solving these issues. The establishment of a basic urban system - even with minimal services and infrastructure - is critical to support the establishment of initial economic activities, provide a base for the provincial administrations, supply basic human needs to the existing population and organize the resettlement effort. This effort would complement the works to recover the national road system and the development of Juba as the national capital and main base of operations of GOSS. After discussing the current issues and conditions, available resources and expected demand, a three phase urban development strategy is suggested to jump start the transformation of the existing settlements into operational urban centres. The development proposal is completed by a brief discussion on urban standards and design recommendations to be adopted.urban; regional; development; planning; strategy; sudan; africa

    The Health Care Crisis in the United States: The Issues and Proposed Solutions by the 2008 Presidential Candidates

    Get PDF
    The United States has state of the art technology and world renowned expertise in medical treatment, yet in terms of healthcare it shows a dramatically poor performance in relation to the other industrialized countries. This situation is surprising, since one would expect that a free market system run almost entirely by the private sector should show a much better performance. This issue has reached the point of being one of the most important national concerns and the subject of serious political and economic arguments - not only regarding how the system should be improved, but also whether it should remain being run by the private sector under a free market approach or whether it should be run by the government and made accessible to the entire population. The first option is supported by the arguments that public initiatives often perform poorly and that free-market competition should prevail. Contrarily, the other side claims that the system is only nominally a free market, that empirical evidence shows it's not working as it should, and that other successful healthcare systems are mostly government operated. As is stands, the health care issue acquired national importance and is presented as a major component of both presidential candidates programs, yet each favoring a different approach to improve accessibility and lower healthcare costs. Republican Senator McCain relies on improving the system by maintaining its current private enterprise, free market characteristics, while Democratic Senator Barrack Obama favours providing universal coverage and lower costs through a higher government intervention in the system. This paper examines the approaches proposed by both candidates and analyses the potential impact their plans may have on the health care system. While the lack of more detailed implementation details makes difficult accessing the effective result of each policy, the comparative review of the alternative approaches presented in this paper will help the reader to to judge for him or herself which could be the more appropriate to upgrade the system and attain a higher performance level.Elections, General Elections, 2008, President, United States, Health Care, Healthcare, Crisis, McCain, Obama, Barack, Democrat, Republican, Private Market, Universal Healthcare, Competition

    A simple model to evaluate relative urban conditions

    Get PDF
    The urban development process intends to enhance urban equipment, infrastructure and services to improve urban conditions and reduce inequalities. While planning activities usually demand a sizeable amount of data to assess these conditions, it is hard to find a straightforward procedure to translate these data into a comprehensive and balanced set of projects and programs. Most urban projects have a strong sectorial character and it is difficult to compare parks with roads or sanitation with schools. Development projects are normally justified in their own terms, yet rarely are sectorial demands equably met by the proposed projects. The following model intends to facilitate this task, providing a simple yet efficient means to assess urban conditions, evaluate and compare the sectorial demands and assemble a balanced set of development goals that can be used to estimate the overall investment needed. The proposed system assesses urban conditions through a set of selected indicators, derived from a compact data base. These indicators represent the performance of the basic urban sectors at each urban zone, thus providing the necessary spatial component to the system. The indicators are normalised to allow comparison of conditions between different sectors. The values of the normalised indicators are then used to evaluate the relative quality of services at each urban zone. By displaying the normalised indicators as bar charts, it is easier to visualise sectorial demands and spatial imbalances. The model is built on a spreadsheet, making fairly easy to verify how much improvement in the sector is needed to attain the desired performance level in each zone. New values can be entered interactively until a preferred urban conditions pattern is attained. The information produced by the model can be used as the basic guideline to dimension sectorial projects and compose a comprehensive development program. Besides describing and discussing all the procedures adopted, a simple yet complete example illustrates the use of the model.planning; urban; development; model; infrastructure; condition; regional

    Bouchaud-M\'ezard model on a random network

    Full text link
    We studied the Bouchaud-M\'ezard(BM) model, which was introduced to explain Pareto's law in a real economy, on a random network. Using "adiabatic and independent" assumptions, we analytically obtained the stationary probability distribution function of wealth. The results shows that wealth-condensation, indicated by the divergence of the variance of wealth, occurs at a larger JJ than that obtained by the mean-field theory, where JJ represents the strength of interaction between agents. We compared our results with numerical simulation results and found that they were in good agreement.Comment: to be published in Physical Review

    Gamma-distribution and wealth inequality

    Full text link
    We discuss the equivalence between kinetic wealth-exchange models, in which agents exchange wealth during trades, and mechanical models of particles, exchanging energy during collisions. The universality of the underlying dynamics is shown both through a variational approach based on the minimization of the Boltzmann entropy and a complementary microscopic analysis of the collision dynamics of molecules in a gas. In various relevant cases the equilibrium distribution is the same for all these models, namely a gamma-distribution with suitably defined temperature and number of dimensions. This in turn allows one to quantify the inequalities observed in the wealth distributions and suggests that their origin should be traced back to very general underlying mechanisms: for instance, it follows that the smaller the fraction of the relevant quantity (e.g. wealth or energy) that agents can exchange during an interaction, the closer the corresponding equilibrium distribution is to a fair distribution.Comment: Presented to the International Workshop and Conference on: Statistical Physics Approaches to Multi-disciplinary Problems, January 07-13, 2008, IIT Guwahati, Indi

    Adaptive networks of trading agents

    Full text link
    Multi-agent models have been used in many contexts to study generic collective behavior. Similarly, complex networks have become very popular because of the diversity of growth rules giving rise to scale-free behavior. Here we study adaptive networks where the agents trade ``wealth'' when they are linked together while links can appear and disappear according to the wealth of the corresponding agents; thus the agents influence the network dynamics and vice-versa. Our framework generalizes a multi-agent model of Bouchand and Mezard, and leads to a steady state with fluctuating connectivities. The system spontaneously self-organizes into a critical state where the wealth distribution has a fat tail and the network is scale-free; in addition, network heterogeneities lead to enhanced wealth condensation.Comment: 7 figure

    k-Generalized Statistics in Personal Income Distribution

    Full text link
    Starting from the generalized exponential function exp‚Ā°őļ(x)=(1+őļ2x2+őļx)1/őļ\exp_{\kappa}(x)=(\sqrt{1+\kappa^{2}x^{2}}+\kappa x)^{1/\kappa}, with exp‚Ā°0(x)=exp‚Ā°(x)\exp_{0}(x)=\exp(x), proposed in Ref. [G. Kaniadakis, Physica A \textbf{296}, 405 (2001)], the survival function P>(x)=exp‚Ā°őļ(‚ąíő≤xőĪ)P_{>}(x)=\exp_{\kappa}(-\beta x^{\alpha}), where x‚ąąR+x\in\mathbf{R}^{+}, őĪ,ő≤>0\alpha,\beta>0, and őļ‚ąą[0,1)\kappa\in[0,1), is considered in order to analyze the data on personal income distribution for Germany, Italy, and the United Kingdom. The above defined distribution is a continuous one-parameter deformation of the stretched exponential function P>0(x)=exp‚Ā°(‚ąíő≤xőĪ)P_{>}^{0}(x)=\exp(-\beta x^{\alpha})\textemdash to which reduces as őļ\kappa approaches zero\textemdash behaving in very different way in the x‚Üí0x\to0 and x‚Üí‚ąěx\to\infty regions. Its bulk is very close to the stretched exponential one, whereas its tail decays following the power-law P>(x)‚ąľ(2ő≤őļ)‚ąí1/őļx‚ąíőĪ/őļP_{>}(x)\sim(2\beta\kappa)^{-1/\kappa}x^{-\alpha/\kappa}. This makes the őļ\kappa-generalized function particularly suitable to describe simultaneously the income distribution among both the richest part and the vast majority of the population, generally fitting different curves. An excellent agreement is found between our theoretical model and the observational data on personal income over their entire range.Comment: Latex2e v1.6; 14 pages with 12 figures; for inclusion in the APFA5 Proceeding

    Reshuffling spins with short range interactions: When sociophysics produces physical results

    Full text link
    Galam reshuffling introduced in opinion dynamics models is investigated under the nearest neighbor Ising model on a square lattice using Monte Carlo simulations. While the corresponding Galam analytical critical temperature T_C \approx 3.09 [J/k_B] is recovered almost exactly, it is proved to be different from both values, not reshuffled (T_C=2/arcsinh(1) \approx 2.27 [J/k_B]) and mean-field (T_C=4 [J/k_B]). On this basis, gradual reshuffling is studied as function of 0 \leq p \leq 1 where p measures the probability of spin reshuffling after each Monte Carlo step. The variation of T_C as function of p is obtained and exhibits a non-linear behavior. The simplest Solomon network realization is noted to reproduce Galam p=1 result. Similarly to the critical temperature, critical exponents are found to differ from both, the classical Ising case and the mean-field values.Comment: 11 pages, 5 figures in 6 eps files, to appear in IJMP

    Design Experience from Experience Design: Towards Strategies for Enhancements

    Get PDF
    • ‚Ķ
    corecore