682 research outputs found

    Genetic algorithm fuzzy clustering using GPS data for defining level of service criteria of urban streets

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    Developing countries like India need to have proper Level of Service (LOS) criteria for various traffic facilities as this helps in planning, design of transportation projects and also allocating resources to the competing projects. The LOS analysis for urban street followed in India is an adaptation of HCM-2000 methodology but the methodology is relevant for developed countries having homogenous traffic flow. In this research an attempt has been made to establish a framework to define LOS criteria of urban street in Indian context keeping in mind the geometric and surrounding environmental characteristics. Defining LOS criteria is basically a classification problem for which cluster analysis is a suitable technique can be applied. In this research a hybrid algorithm comprising of Genetic Algorithm (GA) and Fuzzy C-mean is utilized. As input to the clustering algorithm GA-Fuzzy a lot of speed data is required. From literature review GPS is found to be a suitable tool for collecting second by second speed data and GIS is suitable in handling large amount of speed data. The clustering algorithm is used twice in this study. First the GA-Fuzzy algorithm was used to classify Free Flow Speed (FFS) data into number of classes in order to get the FFS ranges of different urban street classes. To determine the optimal number of cluster using FFS data five cluster validation parameters are considered. After getting the FFS ranges for different urban street classes the same GA-Fuzzy algorithm is used on average travel speed data collected during both peak and off-peak hours to determine the speed ranges of different LOS categories. From this analysis the free flow speed ranges for different urban street classes and the speed ranges for different LOS categories are defined and the values are found to be lower than that suggested by HCM-2000. The coherence of the clustering result in classification of urban streets into four classes and speed values into six LOS categories is agreed with the physical and surrounding environmental characteristics of road segments under the study area. From this analysis it is also found that good LOS can’t be expected from urban street segment for which physical and surrounding environmental characteristics are not good

    Razine cirkulirajućeg histamina i testovi plućne funkcije u radnika iz predionice pamuka

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    Circulating histamine level and forced expiratory volume in one second (FEY1) were measured by conventional methods in 39 selected workers (24 exposed and 15 controls) employed in a local cotton mill. There were 12 workers with byssinosis, who complained of breathlessness and tightness in the chest, showed elevated histamine concentrations in blood and a diminished percentage of predicted FEY1 values. Non-byssinotic subjects who were exposed to cotton dust had lower blood histamine concentrations and a higher percentage of predicted FEY1 values. Both exposed groups exhibited enhanced histamine levels and a lower percentage of predicted FEV1 values than unexposed subjects. The circulating histamine concentrations were negatively correlated with FEV1 among exposed workers.Razine cirkulirajućeg histamina i testovi plućne funkcije u radnika iz predionice pamuk

    Consequences of an attractive force on collective modes and dust structures in a strongly coupled dusty plasma

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    We present an investigation of the combined effects of the Debye-Huckel (DH) repulsive and overlaping Debye spheres (ODS) attractive interaction potentials around charged dust particles on collective modes, phase separation and ordered dust structures in a strongly coupled dusty plasma. We obtain static and dynamical information via Molecular Dynamics simulations in the liquid and crystallized phases and identify the onset of an instability in the transverse collective mode, by using (zero-temperature) lattice summation method. The present results are useful for understanding the origin of coagulation/agglomeration of charged dust particles and the formation of ordered dust structures in low-temperature laboratory and space dusty plasmas

    Ecological taxes in some European countries

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    Production and consumption of fossil fuels is one of the major causes of the green house effect, which is in economics known as a form of ecological externality. Fiscal solution, as one way of internalization of externalities, is based on polluters-pay principle and the imposition of tax on emission. Although the implementation of ecological tax was intensified during the previous decade, fiscal revenues are modest and account for only 5% of the total fiscal revenues of the European Union. Taxes on energetic products, accounting for 76%, are dominant among ecological taxes. Since the EU Directive 82/92 imposes minimum excise rates on oil products, during the last decade Central Eastern European countries have increased excise rates on fossil fuels and fully engaged in the field of ecological policy

    A self-consistent approach to measure preferential attachment in networks and its application to an inherent structure network

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    Preferential attachment is one possible way to obtain a scale-free network. We develop a self-consistent method to determine whether preferential attachment occurs during the growth of a network, and to extract the preferential attachment rule using time-dependent data. Model networks are grown with known preferential attachment rules to test the method, which is seen to be robust. The method is then applied to a scale-free inherent structure network, which represents the connections between minima via transition states on a potential energy landscape. Even though this network is static, we can examine the growth of the network as a function of a threshold energy (rather than time), where only those transition states with energies lower than the threshold energy contribute to the network.For these networks we are able to detect the presence of preferential attachment, and this helps to explain the ubiquity of funnels on energy landscapes. However, the scale-free degree distribution shows some differences from that of a model network grown using the obtained preferential attachment rules, implying that other factors are also important in the growth process.Comment: 8 pages, 8 figure

    Nonintegrable Interaction of Ion-Acoustic and Electromagnetic Waves in a Plasma

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    In this paper we re-examine the one-dimensional interaction of electromagnetic and ion acoustic waves in a plasma. Our model is similar to one solved by Rao et al. (Phys. Fluids, vol. 26, 2488 (1983)) under a number of analytical approximations. Here we perform a numerical investigation to examine the stability of the model. We find that for slightly over dense plasmas, the propagation of stable solitary modes can occur in an adiabatic regime where the ion acoustic electric field potential is enslaved to the electromagnetic field of a laser. But if the laser intensity or plasma density increases or the laser frequency decreases, the adiabatic regime loses stability via a transition to chaos. New asymptotic states are attained when the adiabatic regime no longer exists. In these new states, the plasma becomes rarefied, and the laser field tends to behave like a vacuum field.Comment: 19 pages, REVTeX, 6 ps figures, accepted for publication in Phys. Rev.

    Disordered Type-II Superconductors: A Universal Phase Diagram for Low-Tc_c Systems

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    A universal phase diagram for weakly pinned low-Tc_c type-II superconductors is revisited and extended with new proposals. The low-temperature ``Bragg glass'' phase is argued to transform first into a disordered, glassy phase upon heating. This glassy phase, a continuation of the high-field equilibrium vortex glass phase, then melts at higher temperatures into a liquid. This proposal provides an explanation for the anomalies observed in the peak effect regime of 2H-NbSe2_2 and several other low-Tc_c materials which is independent of the microscopic mechanisms of superconductivity in these systems.Comment: 23 pages, 9 figure

    Urea treatment of straw.

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    BACKGROUND: Motivation is a critical factor in supporting sustained exercise, which in turn is associated with important health outcomes. Accordingly, research on exercise motivation from the perspective of self-determination theory (SDT) has grown considerably in recent years. Previous reviews have been mostly narrative and theoretical. Aiming at a more comprehensive review of empirical data, this article examines the empirical literature on the relations between key SDT-based constructs and exercise and physical activity behavioral outcomes. METHODS: This systematic review includes 66 empirical studies published up to June 2011, including experimental, cross-sectional, and prospective studies that have measured exercise causality orientations, autonomy/need support and need satisfaction, exercise motives (or goal contents), and exercise self-regulations and motivation. We also studied SDT-based interventions aimed at increasing exercise behavior. In all studies, actual or self-reported exercise/physical activity, including attendance, was analyzed as the dependent variable. Findings are summarized based on quantitative analysis of the evidence. RESULTS: The results show consistent support for a positive relation between more autonomous forms of motivation and exercise, with a trend towards identified regulation predicting initial/short-term adoption more strongly than intrinsic motivation, and intrinsic motivation being more predictive of long-term exercise adherence. The literature is also consistent in that competence satisfaction and more intrinsic motives positively predict exercise participation across a range of samples and settings. Mixed evidence was found concerning the role of other types of motives (e.g., health/fitness and body-related), and also the specific nature and consequences of introjected regulation. The majority of studies have employed descriptive (i.e., non-experimental) designs but similar results are found across cross-sectional, prospective, and experimental designs. CONCLUSION: Overall, the literature provides good evidence for the value of SDT in understanding exercise behavior, demonstrating the importance of autonomous (identified and intrinsic) regulations in fostering physical activity. Nevertheless, there remain some inconsistencies and mixed evidence with regard to the relations between specific SDT constructs and exercise. Particular limitations concerning the different associations explored in the literature are discussed in the context of refining the application of SDT to exercise and physical activity promotion, and integrating these with avenues for future research
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