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Zelewski, Stephan, i Malte L. Peters. "Fair Distribution of Efficiency Gains in Supply Networks from a Cooperative Game Theory Point of View". International Journal of Information Systems and Supply Chain Management 3, nr 2 (kwiecień 2010): 1–24. http://dx.doi.org/10.4018/jisscm.2010040101.
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In this paper, the authors address the distribution of efficiency gains among partially autonomous supply network actors in a manner they will accept as fair and as an incentive to cooperation. The problem is economically significant because it requires substantiating efficiency gains in an understandable manner. Moreover, supply networks suffer from a conflict potential because the partially autonomous actors seek to maximize their own shares of the efficiency gain. The method applied appropriates a model from cooperative game theory involving the t-value. The special nature of the t-value ensures that it seems rational to the actors to cooperate in the supply network. The proposed method for the distribution problem offers a fair distribution of efficiency gains in the supply network and ensures that the distribution results can be communicated easily.
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Szczepański, Emilian, Ilona Jacyna-Gołda i Jakub Murawski. "GENETIC ALGORITHMS BASED APPROACH FOR TRANSHIPMENT HUB LOCATION IN URBAN AREAS". Archives of Transport 31, nr 3 (30.09.2014): 73–82. http://dx.doi.org/10.5604/08669546.1146989.
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Points of distribution, sales or service are important elements of the supply chain. These are the final elements which are responsible for proper functioning of the whole cargo distribution process. Proper location of these points in the transport network is essential to ensure the effectiveness and reliability of the supply chain. The location of these points is very important also from the consumers point of view. In this paper developed method of points location was present on the example of urban transport network. The developed approach is based on the Vehicle Routing Problem in the multistage distribution systems. The proposed method uses a genetic algorithm. Article also presents a mathematical model of delivery cost as a criterion func
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Pawar, Mukund M., i Nitin P. Sonaje. "Converting Traditional Water Supply Network Into 24x7, using Water GEMS to Optimize Design". International Journal of Recent Technology and Engineering 10, nr 1 (30.05.2021): 280–84. http://dx.doi.org/10.35940/ijrte.a5937.0510121.
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Water is all-natural driving force. Entire world struggles to preserve it. Given that India is among the top 12 water poor countries, water wastage is a critical issue for us. India's population is increasing day by day and thus the demand for water is continuously increasing. This growing demand can be met through an efficient water distribution network which can be designed using modern hydraulic software such as Water GEMS. Using the Water GEMS software Pandharpur city is selected to convert existing water supply system into 24 * 7 continuous water supply systems. The largest investment is the pipes used in the water distribution system. The design, modeling and optimization of pipes in water supply system from an economic point of view are very important. Therefore optimal pipe network design for converting existing network into 24x7 water supply system networks is carried out in this paper to reduce the cost using WaterGEM software. Study of the existing water supply network system for one zone (Ambika Nagar Zone10) is initially carried out from the Pandharpur area. The effect on demand, head loss gradient, and pressure development of the forecasted population is studied. In addition, cost optimization of the pipe network for the proposed 24x7 water supply system is carried out using a genetic algorithms Darwin optimization approach.
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Frankowska, Marzena, Andrzej Rzeczycki, Mariusz Sowa i Wojciech Drożdż. "Functional Model of Power Grid Stabilization in the Green Hydrogen Supply Chain System—Conceptual Assumptions". Energies 16, nr 1 (23.12.2022): 154. http://dx.doi.org/10.3390/en16010154.
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Green hydrogen supply chain includes supply sources, production, and distribution of hydrogen produced from renewable energy sources (RES). It is a promising scientific and application area, as it is related to the problem of instability of power grids supplied with RES. The article presents the conceptual assumptions of the research on the design of a functional multi-criteria model of the stabilization model architecture of energy distribution networks based on a hydrogen energy buffer, taking into account the applicable use of hydrogen. The aim of the research was to identify the variables contributing to the stabilization of the operation of distribution networks. The method used to obtain this result was a systematic review of the literature using the technique of in-depth analysis of full-text articles and expert consultations. The concept of a functional model was described as a matrix in two dimensions in which the identified variables were embedded. The first dimension covers the phases of the supply chain: procurement and production along with storage and distribution. The second dimension divides the separate factors into technical, economic, and logistic. The research was conducted in the context of system optimization from the point of view of the operator of the energy distribution system. As a result of the research, several benefits resulting from stabilization using a hydrogen buffer were identified. Furthermore, the model may be used in designing solutions stabilizing the operation of power grids in which there are surpluses of electricity produced from RES. Due to the applied multidimensional approach, the developed model is recommended for use, as it enables the design of solutions in a systemic manner. Due to the growing level of energy obtained from renewable energy sources, the issue of stabilizing the energy network is becoming increasingly important for energy network distributors.
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Shoji, Gaku, i Ayumi Toyota. "Function of Emergency Road Networks During the Post-Earthquake Process of Lifeline Systems Restoration". Journal of Disaster Research 7, nr 2 (1.02.2012): 173–83. http://dx.doi.org/10.20965/jdr.2012.p0173.
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This paper aims to present a framework for evaluating the functionality of emergency road networks after an earthquake from the perspective of local assistance during the process of restoring lifeline systems, such as electric power supply systems, gas supply systems and telecommunication networks. For the analysis, an earthquake of M7.3 in the Tokyo metropolitan area is anticipated, and the following types of local assistance between the related bases and the lifeline systems in the Kanto area are assumed. We employ four indices to quantify the physical and functional states of emergency road networks to be used during the post-earthquake restoration process: distance exposed by seismic intensity spatial distribution and distance exposed by PL value spatial distribution, the indices of which denote the physical state of the road networks as a result of ground motions and liquefaction, distance weighted by traffic congestion level, and distance weighted by averaged traveling time during the congestion, the indices of which denote the functional state of the road networks before being subjected to the above-mentioned seismic disturbances. By using the indices to evaluate the function of the networks from the point of view of efficiency in terms of gathering human resources and restoration materials, we can determine the most effective emergency road networks and related bases to provide local assistance to lifeline systems.
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Wang, Wen Xing, i Guang Zheng Wang. "Research and Design of Multigrounded in Micro-Grid Power Supply with Analysis of Electricity Energy". Advanced Materials Research 648 (styczeń 2013): 210–13. http://dx.doi.org/10.4028/www.scientific.net/amr.648.210.
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After a large number of distributed electricity energy has been accessed to network, the system structure and operating characteristics of the distribution network will be greatly changed. The multigrounding of the micro-grid system was discussed from the provisions of the relevant electrical standards and the view of practical point. It is clear that PE wire is the repeated grounding instead of N repeated grounding in the TN system of micro-grid, and multigrounding problems that should be attention were described in TN-S and TT systems of micro-grid.
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Borrás-Talavera, María Dolores, Juan Carlos Bravo i César Álvarez-Arroyo. "Instantaneous Disturbance Index for Power Distribution Networks". Sensors 21, nr 4 (14.02.2021): 1348. http://dx.doi.org/10.3390/s21041348.
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The stability of power systems is very sensitive to voltage or current variations caused by the discontinuous supply of renewable power feeders. Moreover, the impact of these anomalies varies depending on the sensitivity/resilience of customer and transmission system equipment to those deviations. From any of these points of view, an instantaneous characterization of power quality (PQ) aspects becomes an important task. For this purpose, a wavelet-based power quality indices (PQIs) are introduced in this paper. An instantaneous disturbance index (ITD(t)) and a Global Disturbance Ratio index (GDR) are defined to integrally reflect the PQ level in Power Distribution Networks (PDN) under steady-state and/or transient conditions. With only these two indices it is possible to quantify the effects of non-stationary disturbances with high resolution and precision. These PQIs offer an advantage over other similar because of the suitable choice of mother wavelet function that permits to minimize leakage errors between wavelet levels. The wavelet-based algorithms which give rise to these PQIs can be implemented in smart sensors and used for monitoring purposes in PDN. The applicability of the proposed indices is validated by using a real-time experimental platform. In this emulated power system, signals are generated and real-time data are analyzed by a specifically designed software. The effectiveness of this method of detection and identification of disturbances has been proven by comparing the proposed PQIs with classical indices. The results confirm that the proposed method efficiently extracts the characteristics of each component from the multi-event test signals and thus clearly indicates the combined effect of these events through an accurate estimation of the PQIs.
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De Felice, Fabio, i Antonella Petrillo. "A Strategic Multicriteria Decision Support System to Assess the Best Supply Chain Distribution Strategy and Characterize the Bullwhip Effect". International Journal of Information Systems and Supply Chain Management 6, nr 4 (październik 2013): 61–76. http://dx.doi.org/10.4018/ijisscm.2013100104.
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The attention on optimal management of production systems has increased, thus the control of production with local control of the coordination of an entire chain of production and distribution (Supply Chain Management). The aim of this work is to analyze some issues relating to new types of production realities based on the Supply Chain, to show the multiple causes of the change in demand along a Supply Chain, the reasons that cause the Bullwhip Effect and the techniques to improve it. From this point of view the authors have developed a strategic multicriteria decision support system based on the Analityc Network Process with which the authors can analyze the criticality throughout the supply chain process. Definitively this paper introduces a conceptual framework for evaluating different supply chain structures in the context of Bullwhip Effect. The authors also illustrate the applicability of the resulting framework through a specific model applied in an automotive industry.
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Valery, Lukinskiy, i Lukinskiy Vladislav. "Designing the Analytical Base for Optimal Allocation of Stocks in Supply Chains". Transport and Telecommunication Journal 19, nr 4 (1.12.2018): 346–55. http://dx.doi.org/10.2478/ttj-2018-0029.
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Abstract The carried out studies show that from the point of view of the issue of efficiency increase of logistical systems, there are several key aspects. Firstly, choice of methods for managing the triad of logistics functions ‘inventory management - warehousing – transportation’, where the inventory management issues are considered as the most relevant ones. Secondly, there is recognized the need to move the studies of multi-level systems within the framework of the concept of supply chain management. Nowadays, supply chains, which are represented by the distribution system, are widespread in practice. The most common of them are two-level ones with a central supplier at the second level and a certain number of companies at the first level; and multi-level systems of the distribution configuration network in which multi-nomenclature stocks are located. The article is devoted to the design and enhancement of analytical platform for inventory management in such distribution systems.
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Kyzym, Mykola O., Tetiana I. Salashenko i Yevhen I. Kotliarov. "Development of Heat Energy Markets: Experience of European Countries and Conclusions for Ukraine". Business Inform 11, nr 538 (2022): 64–75. http://dx.doi.org/10.32983/2222-4459-2022-11-64-75.
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The purpose of the article is to study the European experience of the functioning of heat energy markets, identify the components of their deregulation, and develop proposals for the formation of regional heat markets in Ukraine. The article stipulates that currently there is no trans-European legislation on the formation of heat energy markets, there are only certain provisions that relate to its production, consumption and accounting. From a theoretical point of view, there are three types of competition in the heat energy markets: between heat supply sources; between producers of centralized heat; between companies for assets. The analyzed experience in the development of heat energy markets in three European countries testifies to the fundamental differences in its structure. Denmark’s heat energy markets are government-regulated, where there is a partial distinction between the functions of production, transportation, and distribution of heat; pricing is carried out on a regulatory basis of non-profit; there are no transparent conditions for access to the network, and the consumer has limited opportunities to disconnect from the system. In Sweden, competition is open at the wholesale level between heat producers; the functions of production and supply are demarcated, and the distribution and supply functions are combined; the retail heat market is self-regulating, which implies the need to coordinate heat prices between suppliers and consumers who, in case of disagreement, have the opportunity to refuse centralized heat supply. Lithuanian heat energy markets are open to wholesale competition and operate in the forward segment, while at the retail level they are regulated, where the transmission from production and supply has been unbundled; regulatory access to heating networks for independent producers has been introduced, and consumers have the right to refuse centralized heat supply. The highlighted features allowed to provide proposals for the formation of heat energy markets in Ukraine, including: the development of competition between heat producers; delimitation of the functions of production, transmission and distribution; formation of its forward, spot and balancing segments; introduction of auctions with the declared pricing method under the pressure of regulatory price restrictions, which are established on the basis of business standards according to the benchmarking system.
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Sekret, Robert. "Environmental aspects of energy supply of buildings in Poland". E3S Web of Conferences 49 (2018): 00097. http://dx.doi.org/10.1051/e3sconf/20184900097.
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The article presents the assessment of the environmental impact of 9 variants of building heat supply for heating purposes. The building energy standards and the main primary energy carriers being in use in Poland were taken as input data. The subject of analysis was a single-family house characterized by a utility energy demand of 47 kWh/(m2 year). An environmental impact analysis was made using the specification for LCA in damage categories encompassing human health, ecosystem quality and natural resources depletion. From the obtained results it has been found that coal-based technologies in Poland's building energy supply systems are capable of reducing the noxious environmental impact. An example of such a system is the effective heat distribution network with a coal-based cogeneration energy source. From the point of view of radical low emission reduction, an interesting solution is the effective heat distribution network with a gas-based cogeneration energy source. Nevertheless, forecasts about the development of renewable energy source installations in Poland indicate that a significant role in building heat supply systems will be played by solar systems and geothermal systems using heat pumps. Achieving the environmental acceptance of heat pumps in Poland's conditions requires a decisive intensification of efforts to increase the share of renewable energy sources in electric energy generation processes in the central electric power system and in local and individual systems, as well as the continuation of the processes of thermal insulation of already existing buildings.
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Tazky, Matej, Michal Regula i Alena Otcenasova. "Impact of Changes in a Distribution Network Nature on the Capacitive Reactive Power Flow into the Transmission Network in Slovakia". Energies 14, nr 17 (27.08.2021): 5321. http://dx.doi.org/10.3390/en14175321.
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The main emphasis in the operation of an electricity system is placed on its safe and reliable operation. The flow of reactive power in a network can affect voltage conditions in individual nodes of the transmission system. In recent years, there have been changes in the network that have resulted in increased capacitive reactive power flows from lower voltage levels to higher ones. These flows can cause the voltage to rise above the limit. This paper examines recent changes in the reactive power transmission in the network, especially at lower voltage levels. The possible impact of these changes on the flow of capacitive reactive power at higher voltage levels is analyzed. This paper also presents a description and the simulated impact of power lines at different voltage levels on reactive power flows. Real measurements of different types of consumers at the low-voltage (LV) level are analyzed. Finally, a simulation model was created to simulate the impact of a customer’s power contribution to the reactive power flows from the point of view of a 110 kV voltage node. This node is characterized as a supply point.
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Hemmati, Mohammad, Mehdi Abapour, Behnam Mohammadi-Ivatloo i Amjad Anvari-Moghaddam. "Optimal Operation of Integrated Electrical and Natural Gas Networks with a Focus on Distributed Energy Hub Systems". Sustainability 12, nr 20 (9.10.2020): 8320. http://dx.doi.org/10.3390/su12208320.
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Coordinated multi-carrier energy systems with natural gas and electricity energies provide specific opportunities to improve energy efficiency and flexibility of the energy supply. The interdependency of electricity and natural gas networks faces multiple challenges from power and gas flow in corresponding feeders and pipes and connection points between two infrastructures’ points of view. However, the energy hub concepts as the fundamental concept of multi-carrier energy systems with multiple conversion, storage, and generation facilities can be considered as a connection point between electricity and gas grids. Hence, this paper proposes an optimal operation of coordinated gas and electricity distribution networks by considering interconnected energy hubs. The proposed energy hub is equipped with combined heat and power units, a boiler, battery energy storage, a heat pump, and a gas-fired unit to meet the heating and electrical load demands. The proposed model is formulated as a two-stage scenario-based stochastic model aiming to minimize total operational cost considering wind energy, electrical load, and real-time power price uncertainties. The proposed integrated energy system can participate in real-time and day-ahead power markets, as well as the gas market, to purchase its required energy. The AC-power flow and Weymouth equation are extended to describe power and gas flow in feeders and gas pipelines, respectively. Therefore, a realistic model for the integrated electricity and gas grids considering coupling constraints is satisfied. The proposed model is tested on the integrated energy system and consists of a 33-bus electrical network and a 6-node gas grid with multiple interconnected energy hubs, where the numerical results reveal the effectiveness of the proposed model.
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Paci, A., R. Bualoti i M. Çelo. "Evaluation of Distribution System Reliability Indices Using Fuzzy Reasoning Approach". European Journal of Electrical Engineering and Computer Science 5, nr 3 (4.05.2021): 1–8. http://dx.doi.org/10.24018/ejece.2021.5.3.264.
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The most fundamental problems in the distribution system are the quality, the continuity, and the power supply. Political and economic changes were accompanied by changes in the structure of the electric load in the distribution network. Lack of investment and aging of the distribution company assets was accompanied by a decrease in the reliability of the distribution system. Identification and classification of assets from the point of view of their maintenance and replacement was one of the problems that were posed to the engineers. Fuzzy logic can be successfully used to evaluate distribution system reliability indices. In this paper fuzzy logic is used to evaluate the distribution system reliability indices of lines and transformers using six input variables. These variables considered the most important are: Age, Operation, Maintenance, Electrical current loading, Exposure and Weather conditions (Wind or Temperature). The fuzzy inferences knowledge-based IF-THEN rule is developed using Matlab Fuzzy software. The detailed analysis of the fuzzy system surfaces shows that the factors taken in consideration are dynamically and accurately connected to each other. The constructed rules based in engineering experience accurately represent the Reliability Indices.
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Zulianti, Putri, Abraham Lomi i Eko Nurcahyo. "Reliability Analysis of Distribution Network Based on Reliability Index Assessment Method: A Case Study." International Journal of Smart Grid and Sustainable Energy Technologies 1, nr 1 (17.12.2019): 24–27. http://dx.doi.org/10.36040/ijsgset.v1i1.186.
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A primary requirement of a modern electric power system is reasonable ability to satisfy the customer load requirements. Electric utilities involve generation, transmission, and distribution facilities each one of which contributes its own inherent difficulties to the problem of satisfying customer requirement. A power system should be designed and expanded the facilities in order to perform its intended function with a reasonable risk. With increasing the electrical energy demand and the potential of disruption that may occur in the system, the distribution system must have high reliability and continues supply to customer. In this case, the reliability of the distribution system needs to be evaluated by monitoring and analyzing the level of distribution system failure in a certain period of time. A study on a practical distribution system with application of automatic circuit reclosers (ACRs) which plays an important role in enhancing the reliability index of system is presented. The reliability index assessment analyze the reliability index of the existing system before and after application of ACRs. From the simulation point of view, the system average interruption frequency index (SAIFI) is about 19.43% or decreased the failure frequent event from 11.4 failure/ customer.year to 9.25 failure/customer.year); while the momentary average interruption frequency index (MAIFI) has decreased from 6.72 failure/customer.year to 5.05 failure/ customer.year, or increase the reliability index of about 24.85%.
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Trębicka, Agnieszka. "Modeling of water age changes in water distribution systems in time and space". Ekonomia i Środowisko - Economics and Environment 83, nr 4 (12.01.2023): 91–102. http://dx.doi.org/10.34659/eis.2022.83.4.498.
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The paper presents a particularly important research variant in the process of modelling water distribution systems (WDS), which is the age of water. The age of the water in the pipes is a parameter that determines the freshness of the water. The main goal of the presented research was to analyse changes in water age by observing the basic parameters: pressure and water flow. As a result of the assumed simulations, potential places of secondary contamination were distinguished. The result of solving the situation was the introduction of all works aimed at eliminating and improving the negative changes by much more frequent monitoring of water in this area for physicochemical and bacteriological properties and regular flushing of pipelines. The research is carried out based on the mathematical model of the water supply network. The Epanet software is used as a research tool, which allows modelling changes in the age of water in the entire water distribution system over time. The basis of the conducted research became the time factor, which plays a particularly important role in the process of managing the water distribution system. Taking into account the time, it was observed how much water remains on a given section from the moment it flows from the inlet and is mixed with water already present throughout the network. A number of simulation options were analysed in terms of the operation of the water distribution system, where the key problem was water stagnation. It should be noted that stagnation of water is particularly dangerous in the case of WDS, the obtained results showed visible places on the tested model. Simulations lasting more than 8, 10 days showed a clear deterioration in its quality. The above studies are of particular importance from the point of view of managing the efficiency of the water supply network. The analysis of water in water supply systems, stagnating and thus ageing, shows that the efficiency of the system significantly decreases. The variability of conditions in the water distribution system also makes the performance of WDS, and especially of pumping units, variable.
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Sychenko, Viktor G., Dmitry O. Bosiy i Eugene M. Kosarev. "Improving the quality of voltage in the system of traction power supply of direct current". Archives of Transport 35, nr 3 (30.09.2015): 63–70. http://dx.doi.org/10.5604/08669546.1185193.
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Purpose of the work is improved approaches to ensure the required quality parameters of voltage in the traction network based on modern technologies and equipment in the application of power distribution system. Actuality. The introduction of high-speed traffic, increase weight standards Train necessitates increasing the carrying capacity of railways. Often the carrying capacity of existing sections electrified at 3.0 kV DC power supply unit limits. Such limitations include voltage decrease on the electric current collector below the allowable value for the normal operation of 2700 (2900 for high-speed V) and heating the contact wires, thereby losing their mechanical strength. Existing power supply system of RS, which have considerable installed traction substations, can not provide the required level of power density traction network for high-speed movement within 1.5 - 2 MW / km and, respectively, the required voltage quality. At the same time, the daily loading of a powerful traction substations in providing intensive schedule of trains does not exceed 20-25%, while the energy loss in traction network peak load increases and reaches 10-15% of the energy consumed. Thus, the existing system of power traction networks is not sufficiently effective and economical, even with the application of existing methods to strengthen them. In our view, the main limiting factor for a given quality of voltage in the traction network is the use of centralized power. From this, the development of measures to improve the quality of voltage in the traction network in the implementation of high-speed traffic in a growing scarcity of energy resources is an urgent task. Scientific novelty. Using distributed power supply system with adjustable supply points combined into intelligent power supply, which enables adaptive change the characteristics of the transfer, conversion and consumption and optimize the mode of functioning of the traction power supply is suggested for improving the quality of voltage in the traction network in the implementation of high-speed and heavy traffic. Practical significance. Improving the quality of voltage in the traction network by using the proposed circuit design traction power supply will ensure the desired mode voltage and power characteristics of the traction network in the implementation of high-speed and heavy traffic while reducing electricity losses by 20-30%.
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Simmini, Francesco, Marco Agostini, Massimiliano Coppo, Tommaso Caldognetto, Andrea Cervi, Fabio Lain, Ruggero Carli, Roberto Turri i Paolo Tenti. "Leveraging Demand Flexibility by Exploiting Prosumer Response to Price Signals in Microgrids". Energies 13, nr 12 (14.06.2020): 3078. http://dx.doi.org/10.3390/en13123078.
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The diffusion of distributed energy resources in distribution networks requires new approaches to exploit the users’ capabilities of providing ancillary services. Of particular interest will be the coordination of microgrids operating as an aggregate of demand and supply units. This work reports a model predictive control (MPC) application in microgrids for the efficient energy management of energy storage systems and photovoltaic units. The MPC minimizes the economic cost of aggregate prosumers into a prediction horizon by forecasting generation and absorption profiles. The MPC is compared in realistic conditions with a heuristic strategy that acts in a instant manner, without taking into account signals prediction. The work aims at investigating the effect that different types of energy tariffs have in enhancing the end-users’ flexibility, based on three examples of currently applied tariffs, comparing the two storage control modes. The MPC always achieves a better solution than the heuristic approach in all considered scenarios from the cost minimization point of view, with an improvement that is amplified by increasing the energy price variations between peak and off-peak periods. Furthermore, the MPC approach provides a cost saving when compared to the case considering a microgrid endowed with only photovoltaic units, in which no storage is installed. Findings in this work confirm that storage units better perform when some knowledge of future demand and supply trends is provided, ensuring an economic cost saving and an important service for the overall community.
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Kadam, Sambhaji T., Ibrahim Hassan, Mohammad Azizur Rahman, Athanasios I. Papadopoulos i Panos Seferlis. "Review on Modeling of Vapor Compression Chillers: District Cooling Perspective". International Journal of Air-Conditioning and Refrigeration 28, nr 02 (czerwiec 2020): 2030003. http://dx.doi.org/10.1142/s2010132520300037.
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Energy consumption and its associated consequences can be reduced by implementing district cooling strategies that supply low temperature water to a wide range of end users through chillers and distribution networks. Adequate understanding, performance prediction and further optimization of vapor compression chillers used widely in district cooling plants have been a subject of intense research through model-based approaches. In this context, we perform an extensive review of different modeling techniques used for predicting steady-state or dynamic performance of vapor compression liquid chillers. The explored modeling techniques include physical and empirical models. Different physical models used for vapor compression chillers, based on physics laws, are discussed in detail. Furthermore, empirical models (based on artificial neural networks, regression analysis) are elaborated along with their advantages and drawbacks. The physical models can depict both steady- and unsteady-state performance of the vapor compression chiller; however, their accuracy and physical realism can be enhanced by considering the geometrical arrangement of the condenser and evaporator and validating them for various ecofriendly refrigerants and large system size (i.e., cooling capacity). Apparently, empirical models are easy to develop but do not provide the necessary physical realism of the process of vapor compression chiller. It is further observed that DC plants/networks have been modeled from the point of view of optimization or integration but no efforts have been made to model the chillers with multiple VCR cycles. The development of such models will facilitate to optimize the DC plant and provide improved control strategies for effective and efficient operation.
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de Oliveira Alves Correia, Alessandra, Ana Beatriz Ribeiro Nobre, Elson Mendonca Felici i Daniel Ângelo Macena. "BALNEÁRIO DA AMIZADE: LEVANTAMENTO DE ASPECTOS AMBIENTAIS E ANÁLISE DOS CRITÉRIOS DE BALNEABILIDADE". COLLOQUIUM EXACTARUM 12, nr 2 (18.09.2020): 15–27. http://dx.doi.org/10.5747/ce.2020.v12.n2.e315.
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The Balneário da Amizadeis considered the source that belongs to the hydrographic basin of the upper course of the Limoeiro stream located between the cities of Presidente Prudente and Álvares Machado. The water resource is used in emergency cases to supply the water distribution network of the Basic Sanitation Company of the State of São Paulo, being used for sports, leisure and tourism. In view of the characteris-tics of the place, the objective was to survey the environmental aspects of the study area and analyze the water quality, aiming at comparing the results with the resolution of the National En-vironmental Council. The methodology was based on the Stand-ard Methods for the Examination of Water & Wastewater standard for the analysis of thermotolerant coliforms and Esch-erichia coli from the five collection points and on the characteri-zation of the study area. Taking into account the result of the survey of environmental aspects, it was found that these factors interfered with water quality. In order to assess bathing, the point allowed for access to bathers was considered. When com-paring the results of microbiological parameters, it was noted that the presence of 83.660 thermotolerant coliforms restricts the use for primary contact in point 2, being considered inap-propriate forbathers, as described in CONAMA Resolution No. 274/2000.
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Sanduleac, Mihai, João Martins, Irina Ciornei, Mihaela Albu, Lucian Toma, Vitor Pires, Lenos Hadjidemetriou i Rooktabir Sauba. "Resilient and Immune by Design Microgrids Using Solid State Transformers". Energies 11, nr 12 (3.12.2018): 3377. http://dx.doi.org/10.3390/en11123377.
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Solid State Transformers (SST) may become, in the near future, key technological enablers for decentralized energy supply systems. They have the potential to unleash new technologies and operation strategies of microgrids and prosumers to move faster towards a low carbon-based economy. This work proposes a paradigm change in the hierarchically and distributed operated power systems where SSTs are used to asynchronously connect the many small low voltage (LV) distribution networks, such as clusters of prosumers or LV microgrids, to the bulk power system. The need for asynchronously coupled microgrids requires a design that allows the LV system to operate independently from the bulk grid and to rely on its own control systems. The purpose of this new approach is to achieve immune and resilient by design configurations that allow maximizing the integration of Local Renewable Energy Resources (L-RES). The paper analyses from the stability point of view, through simplified numerical simulations, the way in which SST-interconnected microgrids can become immune to disturbances that occur in the bulk power system and how sudden changes in the microgrid can damp out at the Point of Common Coupling (PCC), thus achieving better reliability and predictability in both systems and enabling strong and healthy distributed energy storage systems (DESSs). Moreover, it is shown that in a fully inverter-based microgrid there is no need for mechanical or synthetic inertia to stabilize the microgrid during power unbalances. This happens because the electrostatic energy stored in the capacitors connected behind the SST inverter can be used for a brief time interval, until automation is activated to address the power unbalance for a longer term.
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Karpachevskiy, Andrey M., Oksana G. Filippova i Pavel E. Kargashin. "GIS-Analysis Of The Ural Power Grid Vulnerability To The Impact Of Sleet And Wind". GEOGRAPHY, ENVIRONMENT, SUSTAINABILITY 15, nr 1 (11.01.2022): 14–25. http://dx.doi.org/10.24057/2071-9388-2021-082.
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In this paper, we describe an experiment of complex power grid structure and wind and sleet mapping of territory using two different network indices: standard edge betweenness centrality and new author’s index – electrical grid centrality. Such analysis of the network allows to identify power lines with high load which could be vulnerable elements of the power grid. It is very important for strategic planning of power grids to reduce the risk of accidents by distributing loads across several lines so that they will be able to reserve each other. As a case territory for this research, we took the Ural united power system in Russia which is greatly exposed to different sleet and wind according to the statistics of the power grid operator. The degree of natural hazard consequences could be compensated by the network structure through alternative paths of energy supply or vice versa – increased if they are absent. At the same time, in this paper we consider that power grids have their own features from the graph theory point of view, for example multiple (parallel) edges, branches, different types of vertices. The existing index of edge betweenness centrality does not perfectly cope with them. We compare two indices characterizing power line importance within the system – betweenness centrality and electrical grid centrality and analyze the network structure features together with the spatial distribution of sleet and wind. As a result, we could identify bottlenecks in the study network. According to this study the most vulnerable power lines were detected, for example 500 kV Iriklinskaya CHP – Gazovaya and 500 kV Yuzhnouralskaya CHP-2 – Shagol power lines, that supply big cities such as Chelyabinsk and Orenburg and a bunch of industries around them.
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Moroz, Mariya V. "The method of redundant design schemes and the method of contour minimization of group water supply and sewerage systems". Journal «Izvestiya vuzov. Investitsiyi. Stroyitelstvo. Nedvizhimost» 11, nr 1 (2021): 60–73. http://dx.doi.org/10.21285/2227-2917-2021-1-60-73.
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Due to the uneven distribution of water resources across the territory of Russia, many settlements and even cities do not have own sources of water supply and reservoirs, where treated wastewater could be discharged. To solve this problem, group and district water supply and sewerage systems are designed, built, and developed, hundreds and even thousands of kilometers long. The construction and operation of such facilities require significant financial investments every year. Therefore, the issues of the choice of routes, the structure of facilities, and particularly the methods of transporting water and wastewater, justifying the locations of water intakes and treat treatment facilities are relevant and require special attention and development of a comprehensive methodology for optimizing the structure and parameters of water supply and sewerage systems. The paper proposes, on the basis of a previously constructed redundant graph, the method of contour minimization of the structure of facilities and ways of supplying water to end users, transporting wastewater to treatment plants by pipelines and trucks. The redundant graph includes all kinds of connections (edges, arcs) that simulate pipelines and trucks, between vertices that simulate existing and new sources of water and wastewater discharges, sewage treatment plants, pumping stations, control tanks, and end users. The method selects the best (from the point of view of minimal life cycle costs) edges, arcs, and vertices of the graph and determines the corresponding parameters of pipeline and road sections of the network and facilities. This method is based on the procedure of traversing the contours and sequentially replacing the branches of the tree with moves, while the best option is remembered in the form of a spanning tree. Based on the results of the performed numerical experiments, it was shown that the use of combined (pipeline and truck) systems for transporting water in terms of life cycle costs is optimal.
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SALOMÃO, Gustavo Lúcio, José Henrique da SILVA, Marcelo Jacomini Moreira da SILVA i Lincon ZADOROSNY. "AVALIAÇÃO DO IMPACTO DA URBANIZAÇÃO EM UM SISTEMA DE ABASTECIMENTO DE ÁGUA". UNIFUNEC CIENTÍFICA MULTIDISCIPLINAR 11, nr 13 (1.09.2022): 1–20. http://dx.doi.org/10.24980/ucm.v11i13.5566.
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O crescimento populacional e a urbanização intensa tendem a alterar os sistemas de abastecimento de água. Diante das ampliações das redes, as simulações hidráulicas tornam-se uma ferramenta de apoio a análises de sistemas de distribuição, pois permitem executar, de modo ágil, simulações estáticas e dinâmicas. O objetivo deste trabalho foi verificar alterações em um sistema de abastecimento existente na cidade de Santana da Ponte Pensa (SP) geradas devido às possíveis ampliações da área urbanizada. As simulações da rede de abastecimento de água foram realizadas com o software EPANET, conforme o Manual do Usuário e análise das condições limites previstas pelas normas NBR 12215-1 (ABNT, 2017) e NBR 12218 (ABNT, 2017), observando os pontos críticos do projeto, obtendo-se assim os maiores e menores valores de pressão, vazão e perda de carga disponíveis na rede. Os resultados indicaram que a área existente está de acordo com os critérios de pressão, vazão e perda de carga estabelecidos pelas normas. Ainda foram simulados dois possíveis planos de aumento da área urbanizada, uma delas ao longo da adutora de água tratada e outra ao final desta, aumentando a malha da rede existente, ambos confirmaram as reduções de pressões e aumento de perdas de cargas unitárias, porém sem atingir os critérios estabelecidos pelas normas. Portanto, o sistema existente está desempenhando os parâmetros necessários para o funcionamento adequado, mas ainda são necessárias constantes manutenções para que não ocorram problemas, além disso, no caso de futuras ampliações, é fundamental realizar uma análise inteligente de formas e modelos do sistema de abastecimento. URBANIZATION IMPACT ANALYSIS OF A WATER SUPPLY SYSTEM ABSTRACT Population growth and intense urbanization tend to affect water supply systems. In view of the expansion of water networks, hydraulic simulations have become a support tool for the distribution systems analysis, because they enable to perform static and dynamic simulations in an efficient way. The purpose of this paper was to examine changes in an existing supply system in the city of Santana da Ponte Pensa (SP) resulting from the possible expansion of the urbanized area. The water supply network simulations were performed with the EPANET software, according to the User's Manual and analysis of the boundary conditions provided by the standards NBR 12215-1 (ABNT, 2017) and NBR 12218 (ABNT, 2017), observing the critical points of the project, thus obtaining the highest and lowest values of pressure, flow and head loss available in the network. The results indicated that the existing area is in accordance with the pressure, flow and head loss criteria established by the standards. Furthermore, two possible plans to increase the urbanized area were simulated; one of them along the treated water pipeline and the other at the end of it, increasing the grid of the existing network, both confirmed the pressure reductions and increase in unit head losses, but without reaching the criteria established by the standards. Therefore, the existing system is performing the necessary parameters for adequate operation, but continuous maintenance is still needed to prevent problems from occurring, moreover, in the case of future expansions, it is essential to conduct an intelligent shape and model analysis of the supply system Keywords: Urbanization. Water Supply. Hydraulic Simulation.
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Labrecque, Joanne, Bertrand Dulude i Sylvain Charlebois. "Sustainability and strategic advantages using supply chain-based determinants in pork production". British Food Journal 117, nr 11 (2.11.2015): 2630–48. http://dx.doi.org/10.1108/bfj-02-2015-0068.
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Purpose – The purpose of this paper is to examine the use of sustainability as strategic cornerstone for a marketing channel in a mature market, particularly in the hog industry in the Canadian Province of Quebec. Due to the growing attention to sustainability, and the international trend toward agricultural trades and stakeholder involvement in food, there is a need for a system-based approach in the field of food systems sustainability. Design/methodology/approach – In total, 12 semi-structured individual interviews were conducted among marketing managers working for different organizations within the Quebec hog marketing channel. The organizations chosen vary depending on the size, level of integration and involvement in the industry, to create a sample that adequately represents the industry. For the purpose of this research, three primary producers, one veterinarian, three licenced abattoirs, one food processor, one distributor, one independent retailer and two types of food service facility, one from a franchise system and the other from a high-end restaurant were questioned regarding the current state of the industry, as well as the impact of sustainable development on their strategic plans. Findings – The Canadian hog and pork industry is currently facing strong competition from several fronts: the USA and South America, a population with increasingly sophisticated demands, a strong Canadian dollar and a significant increase in input costs, particularly in respect to oil and corn. To be able to meet this competition, and in order to prosper in an uncertain marketplace, marketing channel believes that it must reduce its production costs, increase product awareness in the domestic market and promote cooperation among industry members. Research limitations/implications – This research is mainly concerned with the Quebec hog industry. External validity has not been achieved with the current research. In addition, a lack of distributor availability to answer the interview questions limits researchers’ capacity to extrapolate results to all retailers. Meetings with other food distributors would be required to verify the accuracy of results. Although this study is exploratory in nature, several appealing research avenues emerge. First, the research focusses primarily on members of the distribution network, but does not consider the consumers’ point of view. It would be fruitful to study the impact of sustainable development on the perceived product quality by measuring consumers’ intent to purchase. Practical implications – The principal point of interest that makes this case worthy of study and of potential application to future business modeling is how sustainability and sustainable development is perceived throughout various marketing channels. The Quebec hog industry faces strong competition from several countries that are able to offer a similar product at a lower cost. The mature market consists of a limited number of producers interested in offering a product on the market at the lowest possible price. Social implications – When it comes to sustainable development and the hog industry, the economic and environmental aspects seem to be well understood by members of the industry. On the other hand, the social aspect of sustainability is not mentioned frequently and is often not a part of the leaders’ main concerns. Nevertheless, members of the industry agree that sustainable development affects the Quebec hog value chain, and will remain a topic of interest in the coming years. Originality/value – To the knowledge, no study has been conducted to evaluate the use of sustainability as strategic cornerstone for a marketing channel in a mature market, particularly in the hog industry. Many studies have been conducted in a context of emerging markers. However, very few studies addressed the issue in an established economic environment.
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Mauro, Raffaele, i Andrea Pompigna. "A Statistically Based Model for the Characterization of Vehicle Interactions and Vehicle Platoons Formation on Two-Lane Roads". Sustainability 14, nr 8 (14.04.2022): 4714. http://dx.doi.org/10.3390/su14084714.
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Two-lane roads are the most significant part of the road network in many countries, and are widely used for systematic and non-systematic daily travels. Traffic on a two-lane road typically involves a high level of interaction among vehicles, with the formation of platoons. As a part of the road network of a country, they represent a crucial development factor from a social and economic point of view, because they ensure the close accessibility of the innermost areas and local markets, and favor the connection between the nodal points of the logistic system and the last mile of the supply and distribution chain. Thus, the estimation of the presence of vehicle platoons makes it possible to develop significant indicators for performance analysis on this type of road, which in turn is the basis for planning, upgrading, and improving transport programs to find a sustainable balance between environmental, social, and economic qualities. This paper presents a statistically based model, the Two-Lane Roads Statistical Platooning Model (TLR-SPM), which allows for evaluating the percentage of vehicles which are free to travel at the desired speed and of non-free vehicles constrained to travel in platoons at lower speeds than desired, as a function of the traffic flow. Based on a data-driven methodological approach, TLR-SPM allows for going beyond the critical threshold value for time headways, such as the widespread 3 s threshold, but lacks the need to hypothesize, identify, or estimate the probability laws for speed and time headway. From the formal treatment of the general statistical method, the paper shows the data processing procedure through its application to a real case. As shown by the application case and the comparisons with the results of other methods, the proposed model can significantly adapt to the experimental data and can support in analyzing a two-lane road in its operating conditions to promote its safety and efficiency as part of a sustainable transport system.
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SARAPULOVA, Galina. "Assessment of Ulaаnbaаtar sustainable development on the basis of soils geochemical analysis". Sustainable Development of Mountain Territories 15, nr 1 (30.03.2023): 59–66. http://dx.doi.org/10.21177/1998-4502-2023-15-1-59-66.
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Introduction. Assessment of the ecological state of mountainous areas and, especially, large cities, in particular the city of Ulaanbaatar, the study of anthropogenic pressure on sensitive mountain landscapes is very relevant. This is important from the point of view of the contribution of the ecological structural component to the sustainable development of the mountainous area. However, the lack of data on the spatial distribution of the microelement composition of the soil of the urbanized mountainous landscape, especially heavy metals, does not allow a Complex estimationof the ecological state of the territory of the mountainous capital of Mongolia. The purpose of the research: ecological assessment of the soil cover of the metropolis of Ulaanbaatar using geochemical parameters and GIS technologies. Materials and methods of research. Field and physico-chemical methods of studying soils, as well as GIS technologies were used to obtain halo maps of the distribution of anthropogenic pollutants - heavy metals Pb, Cu, Ni, Zn, Hg and oil products. Research results. It was revealed that the key parameter of the state of the soil, the pH indicator, reaches 8-9 units, which means alkalization of the surface soil layer. An active ion-exchange complex has been formed, which leads to the accumulation of technogenic pollutants in the soil. The contents of metals Pb, Cu, Ni, Zn, Hg exceed their standard values based on MPC (MAC). With the use of GIS, halos of their distribution, as well as oil products in the territory of Ulaanbaatar, were obtained. Discussion. Sources of heavy metals are emissions from thermal power plants operating on lignite. Yurts also contribute to severe soil pollution, as they are heated by coal stoves. A large number of personal vehicles and a chaotically located network of gas stations supply metals and petroleum products to the soil. The formation of sparingly soluble fixed forms of metals as a result of alkalization led to their accumulation in the soil. Linear local fields of metal pollution have been identified, which clearly indicate the ecological trouble in the city and the need to take environmental protection measures. Conclusion. The parameters of the geochemical state of techno-genically altered mountain soils in the city of Ulaanbaatar revealed contamination with heavy metals and NPs. Local pollution modules with the accumulation of chemical toxicants have been formed. The halo maps of their distribution are obtained, the formation of a spatially linear type of pollution of the mountain landscape is shown. Offers. The possibility of zoning the territory according to the degree of environmental safety is shown. This should be taken into account in the social and economic aspects of the development of the metropolis, as well as to create a safe living environment for people, to optimize architectural development, to regulate the placement of a network of gas stations, highways and, especially, yurts.
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Abbas, Waseem, i Magnus Egerstedt. "Characterizing heterogeneity in cooperative networks from a resource distribution view-point". Communications in Information and Systems 14, nr 1 (2014): 1–22. http://dx.doi.org/10.4310/cis.2014.v14.n1.a1.
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Tu, Jian, Zhen Hui Huang i Zhen Juan Huang. "Study on the Sensitivity of Selective Leakage Protection of Different Ground of Grid". Advanced Materials Research 765-767 (wrzesień 2013): 2426–29. http://dx.doi.org/10.4028/www.scientific.net/amr.765-767.2426.
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In view of the current direct supply situation of our coal mines high voltage distribution networks commonly used 6kV or 10kV electric cables,on the base of describing mechanism of three different neutral point grounded of underground high voltage distribution networks,detailed analysising three different grounded way of high-voltage power grid parameter sensitivity of leakage protection. The results show that, mine the sensitivity of the high-voltage grid leakage protection and start zero-sequence voltage have a great relationship, the greater the zero-sequence voltage setting value, the device's ability to detect leakage faults weaker corresponding lower sensitivity.
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Mettler, Tobias, Roberto Pinto i David Raber. "An Intelligent Supply Chain Design for Improving Delivery Reliability". International Journal of Information Systems and Supply Chain Management 5, nr 2 (kwiecień 2012): 1–20. http://dx.doi.org/10.4018/jisscm.2012040101.
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In order to flexibly respond to market demands and changing business environments, today’s European machinery and equipment manufacturers are organized in agile, non-hierarchical business networks. As a consequence, relationships with suppliers are often highly volatile, instable and inapprehensible, which in turn causes turbulences with respect to reliability of deliveries. Following the design research paradigm, both practical and knowledge problems are considered by this paper. First, from a practical point of view, a new intelligent supply chain design for non-hierarchical manufacturing networks is developed, that pledges to improve the delivery reliability. Second, from a knowledge point of view, the underlying hypotheses that go along with this new design are validated using structural equation modeling. The results confirm several previously proposed assumptions, including the importance of an electronic procurement process as well as the use of incentive mechanisms for influencing a supplier’s delivery reliability.
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Zhumadilova, M. A., Ye Sh Dussipov i B. Zh Aıtımov. "THE CONCEPT OF LEGAL REGULATION OF ELECTRONIC COMMERCE". REPORTS 2, nr 330 (15.04.2020): 131–38. http://dx.doi.org/10.32014/2020.2518-1483.41.
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The social relations taking place in electronic commerce and the category “electronic commerce” are studied, the qualifying features of this activity are identified, the correlation of the concepts “trade” and “electronic commerce” is made and the author’s definition of the concept and subject of legal regulation of public relations in the field of electronic commerce is developed. Thus, electronic commerce is often considered as a special form of transactions, in which their conclusion and execution is carried out using electronic means of communication. At the same time, the legal characteristics of transactions remain unchanged, and they must be regulated by the rules of law that regulate relations of the appropriate type (purchase-sale, transportation, contract, rent, etc.). According to this position, electronic data exchange does not change the essence of the relationship between the parties and affects only the form in which these relations are built. Within this approach, several points of view have been formed. A number of specialists consider electronic commerce as the production, advertising, sale and distribution of goods using telecommunication networks. Others interpret it as electronic business. In the world practice, the term “trade” has also been widely interpreted so that it covers issues arising from all relations of a commercial nature, both contractual and non-contractual. Trading relationship includes the transactions as follows: any trade transactions for the supply of goods or services or the exchange of goods or services; distribution agreements; commercial representation and agent relations, factoring; leasing; construction of industrial facilities; consulting services; engineering; purchase and sale of licenses; investment; financing; banking services; insurance; operating or concession agreements; joint ventures and other forms of industrial or business cooperation; transportation of goods and passengers by air, sea, train or car. One should recognize that such a broad understanding of trade does not contribute to a detailed study of this concept and it is not suitable in practice. Therefore, the economic meaning of the term "trade" is widely spread in modern science. In a broad sense, trade is considered as a branch of the national economy that ensures the circulation of goods, their movement from the sphere of production to the sphere of circulation. In a narrower sense, trade is defined as economic intermediation between producers and consumers which is carried out by the purchase of goods from producers in order to sell them to consumers and their further sale to other consumers. Electronic commerce is proposed to understand the implementation of actions provided for by law, other operations in the execution of transactions for the sale of goods, work and services based on electronic procedures by the parties of the transaction. At the same time, it is proposed to understand electronic procedures as a special procedure (rules, regulations) for electronic operations in a transaction, and electronic operation on a transaction as performing certain actions by the parties to the transaction to execute the transaction through remote interaction of the parties of the transaction, other entities and their information systems in electronic commerce.
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Ghadiryanfar, M., A. Keyhani, A. Akram i S. Rafiee. "The effect of tractor supply in Iran agriculture from a macro plan point of view". Research in Agricultural Engineering 55, No. 3 (22.09.2009): 121–27. http://dx.doi.org/10.17221/28/2008-rae.
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The aim of this study was to investigate the effect of the tractor supply on agricultural yield from a macro plan perspective. The required information was obtained from the Institute of Agricultural Machinery Extension and Ministry of Jihad-e-Agriculture of Iran. Regarding the number of tractors distributed, the maximum number of tractors distributed in Iran was 37 996 in 1983. The effect of this distribution pattern on the crops yields and planted area was investigated for a thirteen-year period from 1983 to 1996. The results showed that these tractors had significant effects on the crops yields and planted area. Also it was inferred that the power distribution in Iran agriculture with the current trend is not acceptable and no significant changes are expected from the current policy. It seems that the Iran agriculture market needs a shock like that in 1983, and that many tractors with different engine sizes should be supplied into the market in a short period of time.
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Shitu, Sidikat, i Rohaya Mohd Nor. "Rural Women Entrepreneurs Enrolment into Sustainable Supply Chain Networks: From Actor Network Theory Perspective". Journal of Borneo-Kalimantan 4, nr 1 (13.08.2018): 8–13. http://dx.doi.org/10.33736/jbk.916.2018.
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Rural women entrepreneurs in the West African sub-region are focal actors at the bottom of many commodity supply chains. The positions that they occupy in supply chain are susceptible to many forms of sustainability challenges that can obstruct and discourage them from efficiently participating in global supply chains. Despite the critical role of rural women entrepreneurs in the West African subregion has been acknowledged by many, yet the majority of them have not been participated in responsible and sustainable supply chains. In view of these issues, multi-stakeholders are required to collaborate and intervene by developing processes of enrolling rural women entrepreneurs into sustainable supply chain networks. This study presents a case study related to an exploration of the enrolment process utilizing the four moments of translation of the Actor Network Theory (ANT) in the context of the shea butter industry with a cross-border supply chain network. The research found that the enrolment process is shaped by the collaborative relationships within the external context which comprises of several influential stakeholders. Sustainability standards are found to have great potential to serve as an obligatory passage point to transmit sustainability principles to the women within and outside the traditional supply chain networks.
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Soriano, Érico, Luciana de Resende Londe, Leandro Torres Di Gregorio, Marcos Pellegrini Coutinho i Leonardo Bacellar Lima Santos. "Water crisis in São Paulo evaluated under the disaster's point of view". Ambiente & Sociedade 19, nr 1 (marzec 2016): 21–42. http://dx.doi.org/10.1590/1809-4422asoc150120r1v1912016.
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Abstract Brazil's Southeast region has been facing water supply challenges, especially concerning the metropolitan region of São Paulo, since 2014. We adressed the water crisis from the disaster's point of view, considering that one of the guiding features to characterize a disaster is the amount of affected people and the losses associated. In the situation under review, there are people directly affected, because of intermittent house water supply, and indirectly affected by the increase of prices for goods, since their production and manufacturing depend on the availability of water. We presented each of the stages of a disaster risk management: prevention, mitigation, preparedness, response and recovery. The risk of water scarcity in São Paulo is only one aspect of the discussion involving the effectiveness of management processes and the need for investments in the area, especially in reducing wasteful distribution.
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Scott, John G., Jodie Grigg, Monica Barratt i Simon Lenton. "Social capital and cannabis supply". Journal of Sociology 53, nr 2 (3.02.2017): 382–97. http://dx.doi.org/10.1177/1440783316688342.
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The distribution of cannabis in Australia is examined with reference to motivations for supplying drugs. We argue that the distribution of cannabis in Australia is best understood with reference to the concept of social supply, where a supplier, not considered to be a ‘drug dealer proper’, brokers, facilitates or sells drugs, for little or no financial gain to friends and acquaintances. The article draws on data from surveys and interviews with 200 young Australian cannabis users, almost all of whom had also supplied cannabis at some point in their lifetime. We further theorise the concept of social supply with reference to social capital. We argue that a sociological understanding of drug distribution should focus on drug communities, as opposed to markets, describing the features of social organisation that exist between people within social networks and related implications that such features might have in terms of social harm and well-being.
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Bisanovic, Smajo, Mersiha Samardzic i Damir Aganovic. "Economic Valuation of Power and Energy Losses in Distribution Networks". International Journal of Electrical and Computer Engineering (IJECE) 6, nr 2 (1.04.2016): 439. http://dx.doi.org/10.11591/ijece.v6i2.9182.
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This paper presents a framework for determining the price of power and energy at each node in distribution network as well as the price of energy losses in their elements. The proposed framework is based on the concept of the radial structure network and gives one approach to solving the pricing problem that is based on purchase price of power and energy at the network supply point. In this way it is possible to determine the economic value of energy losses whether in the network as a whole or in particular voltage levels. The model has been successfully tested and results from test studies are reported.
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Bisanovic, Smajo, Mersiha Samardzic i Damir Aganovic. "Economic Valuation of Power and Energy Losses in Distribution Networks". International Journal of Electrical and Computer Engineering (IJECE) 6, nr 2 (1.04.2016): 439. http://dx.doi.org/10.11591/ijece.v6i2.pp439-446.
Pełny tekst źródłaStreszczenie:
This paper presents a framework for determining the price of power and energy at each node in distribution network as well as the price of energy losses in their elements. The proposed framework is based on the concept of the radial structure network and gives one approach to solving the pricing problem that is based on purchase price of power and energy at the network supply point. In this way it is possible to determine the economic value of energy losses whether in the network as a whole or in particular voltage levels. The model has been successfully tested and results from test studies are reported.
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Benedetto, Graziella, i Maria Bonaventura Forleo. "Foodies' movement fostering stakeholders' networks: A regional case study". Economia agro-alimentare, nr 3 (styczeń 2021): 1–31. http://dx.doi.org/10.3280/ecag3-2020oa11044.
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The central theme of this work revolves around the foodies' movement under three perspectives: firstly, from a conceptual point of view to give account of its relevance in terms of consumer demand; secondly, to verify how, from the supply side, this movement can to some extent encourage and/or strengthen the creation of networks of local actors indispensable to encourage the meeting between the needs of the demand and supply of typical food products; thirdly, based on a case study to demonstrate that the movement of foodies can be exploited within a political action aimed at reorienting local tourism development. A national case study – Alghero, IT – was analysed. By positioning the rural and urban spaces with respect to the foodies' phenomenon, the existence/absence of networks between local stakeholders some obstacles emerged so as many opportunities. The stakeholder analysis was appliedand discussed. This method was very useful for identifying the role, power and leadership that the various local actors have in favoring or hindering the creation of connection networks between the city and the countryside, and in the requalification of the supply of typical foods that fit well into the current demand trend.
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Ferrarese, Giacomo, i Stefano Malavasi. "Perspectives of Water Distribution Networks with the GreenValve System". Water 12, nr 6 (1.06.2020): 1579. http://dx.doi.org/10.3390/w12061579.
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In recent years, water utilities have made worldwide investments targeted to the implementation of an effective monitoring system and the installation of pressure-reducing valves in strategic nodes of water distribution networks. In fact, these interventions are considered fast and effective solutions to address at least two main concerns of modern water utilities: leakage reduction and energy efficiency. The present paper, on the basis of a database of working conditions of installed pressure-reducing valves, discusses the range of applicability of the GreenValve system (GVS) as an alternative solution to improving standard pressure-reducing valve capabilities. The device is able to recover energy, and it can be used to create a stand-alone monitoring node with remote control ability, optimizing the network from an energetic, functional, and hydraulic point of view.
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Perju, Sorin, Mădălin Mihailovici i Ioana Stănescu. "Simulation of Two High Pressure Distribution Network Operation in one-Network Connection". Mathematical Modelling in Civil Engineering 10, nr 3 (1.09.2014): 27–35. http://dx.doi.org/10.2478/mmce-2014-0013.
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Abstract The programs developed by the water supply system operators in view of metering the branches and reducing the potable water losses from the distribution network pipes lead to the performance reassessment of these networks. As a result the energetic consumption of the pumping stations should meet the accepted limits. An essential role in the evaluation of the operation parameters of the network performance is played by hydraulic modeling, by means of which the network performance simulation can be done in different scenarios. The present article describes the concept of two high-pressure network coupling. These networks are supplied by two repumping stations, in which the water flows were drastically reduced due to the present situation
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Muleta, Tolesa Hundesa, i Legesse Lemecha Obsu. "Analysis of Traffic Evolution on Road Networks of a Roundabout". Journal of Applied Mathematics 2020 (5.10.2020): 1–18. http://dx.doi.org/10.1155/2020/3959613.
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In this paper, the analyses of traffic evolution on the road network of a roundabout having three entrances and three exiting legs are conducted from macroscopic point of view. The road networks of roundabouts are modeled as a merging and diverging types 1×2 and 2×1 junctions. To study traffic evolution at junction, two cases have been considered, namely, demand and supply limited cases. In each case, detailed mathematical analysis and numerical tests have been presented. The analysis in the case of demand limited showed that rarefaction wave fills the portion of the road network in time. In the contrary, in supply limited case, traffic congestion occurs at merging junctions and shock wave propagating back results in reducing the performance of a roundabout to control traffic dynamics. Also, we illustrate density and flux profiles versus space discretization at different time steps via numerical simulation with the help of Godunov scheme.
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FAN, ZHENGPING, i GUANRONG CHEN. "EVOLVING NETWORKS DRIVEN BY NODE DYNAMICS". International Journal of Modern Physics B 18, nr 17n19 (30.07.2004): 2540–46. http://dx.doi.org/10.1142/s0217979204025634.
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In this paper, a new model of evolving networks is proposed based on the dynamical behaviors of nodes in the network. The probability that an existing node in the current network receives a new link from the newly added node is proportional to the defined "activity" of that particular node, which is equivalent to the energy signal of the system from a control theory point of view. This network is found to have the scale-free feature with the degree distribution in a power-law form. This model provides another explanation for the emergence of scale-free networks in many real-world examples.
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Carazas, Rafael Romero, Robinson Bernardino Almanza Cabe, Fabiola Cruz Navarro Soto, Juan Carlos Guevara Jiménez, Doris Rosario Yaya Castañeda, Yta Zunilda Olortegui Cristobal, Dometila Mamani Jilaja i Manuela Daishy Casa-Coila. "Distribution and Export Logistics: Commercial Development of the Millenary Product Chenopodium Quinoa". International Journal of Membrane Science and Technology 10, nr 2 (21.06.2023): 994–1001. http://dx.doi.org/10.15379/ijmst.v10i2.1369.
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The objective of this article was the commercial development of the millenary product Chenopodium Quinoa from a perspective of distribution and export logistics. Methodologically, it was a documentary research that used content analysis as a strategy for the review of the texts, which were retrieved through the following databases: a) Scopus, b) Scielo, c) Web of Science - WoS and, d) Google Scholar, and selected based on the criteria: (a) original or review scientific articles, (b) published in Spanish or English language, (c) temporal delimitation to the last eight years (2015-2022), (d) citable documents, resulting in a total of fourteen reviewed articles (n=14). The bibliographic analysis allowed discriminating from an analytical point of view the supply chain from the quinoa production source, markets and logistic corridors to its export point. This literature review demonstrated that the creation of a more efficient supply chain (distribution logistics) would be beneficial for all parties involved, as it would expedite the circulation of the product, improve responsiveness to customer needs and encourage creative problem solving in the service of distribution and export, validating it from a documentary and bibliographic perspective.
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Bylka, Jedrzej, i Tomasz Mróz. "Exergy Evaluation of a Water Distribution System". Energies 13, nr 23 (26.11.2020): 6221. http://dx.doi.org/10.3390/en13236221.
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The water supply system is one of the most important elements in a city. Currently, many cities struggle with a water deficit problem. Water is a commonly available resource and constitutes the majority of land cover; however, its quality, in many cases, makes it impossible to use as drinking water. To treat and distribute water, it is necessary to supply a certain amount of energy to the system. An important goal of water utility operators is to assess the energy efficiency of the processes and components. Energy assessments are usually limited to the calculation of energy dissipation (sometimes called “energy loss”). From a physical point of view, the formulation of “energy loss” is incorrect; energy in water transport systems is not consumed but only transformed (dissipated) into other, less usable forms. In the water supply process, the quality of energy—exergy (ability to convert into another form)—is consumed; hence, a new evaluation approach is needed. The motivation for this study was the fact that there are no tools for exergy evaluation of water distribution systems. A model of the exergy balances for a water distribution system was proposed, which was tested for the selected case studies of a water supply system and a water treatment station. The tool developed allows us to identify the places with the highest exergy destructions. In the analysed case studies, the highest exergy destruction results from excess pressure (3939 kWh in a water supply system and 1082 kWh in a water treatment plant). The exergy analysis is more accurate for assessing the system compared to the commonly used energy-based methods. The result can be used for assessing and planning water supply system modernisation.
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Dombay, Gábor. "WATER SAFETY PLANS FROM THE ENGINEER’S PERSPECTIVE". YBL Journal of Built Environment 1, nr 2 (1.12.2013): 5–12. http://dx.doi.org/10.2478/jbe-2013-0007.
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Abstract Water safety plans are public health related risk management plans, covering the entire water supply system, based on the theorem of prevention. Risk evaluation is fundamental for setting up a risk management system. A modified risk assessment equation is shown which takes into account the severity of consequences of the hazard an accentuated way. This method was used successfully n a number of practical water safety system applications. Water safety plans are practical tools for water utility operators which can be applied in different fields of operation, from water quality improvement of decision support tool of developments. The role of the distribution system and its operation is clarified from water quality deterioration and risk mitigation point of view.
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Bertino, Lorenzo. "Agency Agreement: From Innominate Contract to the Reference Model of Commercial Distribution Agreements". European Business Law Review 29, Issue 4 (1.07.2018): 643–69. http://dx.doi.org/10.54648/eulr2018025.
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The purpose of this article is to demonstrate that some Italian rules in relation to the commercial agent also can be applied to the distributor. The few Italian judgements rendered on this matter state that rules governing the commercial agent are not applicable to the distribution contract: this innominate contract could be governed through applying by analogy the regulation of supply contract. This Italian Courts’ point of view could be revised. This analysis is based on an historical approach and on the examination of case law in the German, English and Italian legal systems. The historical analysis demonstrates that Italian legislator has regulated the commercial agent contract as a framework model for all distribution contracts. An analysis of the case law demonstrates that in some legal systems the commercial agent’s regulation can sometimes be applied to the distribution contract.
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Babiarz, Bożena, i Paweł Kut. "District heating simulation in the aspect of heat supply safety". E3S Web of Conferences 45 (2018): 00005. http://dx.doi.org/10.1051/e3sconf/20184500005.
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District heating systems as strategic objects from the point of view of state security must ensure reliability and security in supply of heat to their customers [1, 2]. Thanks to computer simulation methods, district heating companies can analyse the operation of the heating networks at the design and operation stage. Computer simulations also offer a wide range of possibilities in the aspect of optimization of the district heating operation as well as prediction and analysis of network failure effects [3-6]. The paper concerns the simulation of a district heating network. The methods for the simulation of heating networks were characterized and simulations of district heating system were carried out. The effects of the failure were analysed at different values of outside temperatures and for different durations of failure. The value of compensation for undelivered heat was also determined. Simulations were carried out for an actual district heating system located in Rzeszow.
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Paffrath, Silvia Fernanda. "Microgeração de energia com uso de bomba funcionando como turbina (BFT) em sistemas de abastecimento de água (SAA)". Revista DAE 221, nr 68 (10.12.2019): 53–59. http://dx.doi.org/10.36659/dae.2020.005.
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Resumo Cada vez mais têm sido estudadas formas de minimizar gastos com energia e/ou de obter formas alternativas de geração, principalmente pela diminuição de oferta hídrica em diversos locais. Nos sistemas de abastecimento de água, são altos os gastos com energia, principalmente nas estações elevatórias. Em sistemas que fazem a distribuição de água por gravidade, não é rara a utilização de válvulas redutoras de pressão em pontos especí- ficos em que é necessária essa redução para garantir condições favoráveis de transporte de água na tubulação. Nesse sentido, ocorre dissipação de energia que poderia ser aproveitada no próprio sistema. Tendo em vista esse aproveitamento energético, esse estudo tem como objetivo determinar de forma teórica a potência gerada por uma bomba funcionando como turbina em locais onde há excedente de pressão, tomando por base dados de um sistema teórico de abastecimento de água de município de pequeno porte. Os resultados mostram que a alternativa é tecnicamente viável, gerando 2,2 KW de potência e 16,4 MW/ano de energia, que poderia ser uti- lizada no próprio sistema, em pontos onde seria necessário bombeamento, seja na captação ou na própria rede de abastecimento, em transição de zonas baixas para altas. Palavras-chave: Eficiência energética. Bomba funcionando como turbina (BFT). Abstract It has increasingly been studied ways to minimize energy costs and to obtain alternative forms of generation, mainly by the reduction of water supply in various locations. In water supply systems, energy costs are high, especially in pumping stations. In systems that make the distribution of water using gravity, it is not uncommon to use pres- sure reducing valves at specific points at which this reduction is necessary to ensure favorable conditions of water transport in the pipe. In this sense, there is dissipation of energy that could be used in the system itself. In view of this energy use, this study aims to determine theoretically the power generated by a pump functioning as turbine in places where there is excess pressure, based on data from a theoretical system of a small town water supply. From the results, the alternative proved to be technically feasible, with power generated at 2.2 KW and energy at 16.4 MW/year, which could be used in the system itself, at points where pumping would be required, either on capture or in the supply network, in transition from low to high areas. Keywords: Energy efficiency. pump functioning as turbine.
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Shuntov, V. P., O. S. Temnykh i S. V. Naydenko. "ONCE AGAIN ON FACTORS LIMITING THE NUMBER OF PACIFIC SALMONS (ONCORHYNCHUS SPP., FAM. SALMONIDAE) DURING THE OCEANIC PERIOD OF THEIR LIFE". Izvestiya TINRO 196 (5.04.2019): 3–22. http://dx.doi.org/10.26428/1606-9919-2019-196-3-22.
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Two different views on factors limiting the abundance of pacific salmons in the marine period of their life are compared. According to traditional point of view, food resources are limited in the marine and oceanic epipelagic biotopes, so a strong competition for food exists between different species of genus Oncorhynchus or between pink salmon O. gorbuscha and other species that makes theIr abundance lower and biological conditions worse. Negative anomaly of the sea surface temperature is considered traditionally as a factor controlling the salmons distribution in the ocean because of the food supply worsening. The other point of view is proposed by authors in the 1980s and is based on comprehensive ecosystem studies of the Far Eastern Seas and the North Pacific. Following to this view, the food resources do not limit the abundance of salmons, which play secondary roles in trophic networks within the subarctic epipelagic layer. Besides, these data do not confirm stenotherm habits of salmons, particularly in conditions of low temperature (salmons could be found in the northern Bering and Okhotsk Seas even in winter). In favor of the latter view, new data are presented for 2018, when the highest biomass of the Russian salmons was observed, primarily due to pink salmon abundance, and the absolutely record Russian catch of pacific salmons in 677,200 t was landed.
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Marin, Andrea. "PRODUCT-FORM IN G-NETWORKS". Probability in the Engineering and Informational Sciences 30, nr 3 (18.05.2016): 345–60. http://dx.doi.org/10.1017/s0269964816000048.
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The introduction of the class of queueing networks called G-networks by Gelenbe has been a breakthrough in the field of stochastic modeling since it has largely expanded the class of models which are analytically or numerically tractable. From a theoretical point of view, the introduction of the G-networks has lead to very important considerations: first, a product-form queueing network may have non-linear traffic equations; secondly, we can have a product-form equilibrium distribution even if the customer routing is defined in such a way that more than two queues can change their states at the same time epoch. In this work, we review some of the classes of product-forms introduced for the analysis of the G-networks with special attention to these two aspects. We propose a methodology that, coherently with the product-form result, allows for a modular analysis of the G-queues to derive the equilibrium distribution of the network.