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1
EN
This paper presents a dynamic model of a palletised load unit during a static tilt test. The stability (also called rigidity) of a load unit was evaluated. The palletised load unit was built of packages forming layers and protected against disintegration by stretch film. The aim of this study was to compare the results of a static tilt test with a commonly used and recommended dynamic acceleration test.
EN
The article is devoted to the issue of the negative effect of delays in the movement of special rescue vehicles on the effectiveness of their mission. The dependence of the area of fire on the delay of the arrival of firefighters using a fire-rescue vehicle is shown. The cascading graph of route options of special vehicle movement to the place of an emergency call is given. The algorithm of the optimal route choice of the special vehicle motion with given projected delays is offered. Based on the graph theory, probability theory, and the basic principles of traffic organization, the article proposes a new way to determine the optimal route.
EN
Unsignalized intersections belong to the most common ways of traffic management at intersections. The capacity of the minor entries depends on many factors. One of them is the traffic flow pattern on the major street. In the case of slow-moving queue of vehicles on the main street caused by a downstream traffic signal, the capacity of movements on the minor street joining the queue of vehicles on the main street is significantly reduced. The surveys of traffic parameters were performed in three Polish cities: Wroclaw, Opole, and Krakow. On the basis of these studies, a simulation model representing the traffic conditions at such an intersection was developed. The influence of pedestrian traffic and the number of storage spaces in the median on the possibility of vehicles from the minor entries joining the queue of vehicles on the main street was examined.
PL
Skrzyżowania bez sygnalizacji są jednym z najczęściej występujących sposobów organizacji ruchu na skrzyżowaniach. Przepustowość wlotów podporządkowanych uzależniona jest od wielu czynników. Jednym z nich jest sposób poruszania się pojazdów na jezdni głównej. W przypadku obecności poruszającej się powoli kolejki pojazdów spowodowanej przez oddziaływanie skrzyżowania z sygnalizacją, przepustowość relacji włączających się do kolejki z wlotów podporządkowanych jest znacznie ograniczona. Pomiary parametrów ruchu przeprowadzono w trzech miastach: Wrocławiu, Opolu i Krakowie. Na podstawie badań opracowano model symulacyjny odzwierciedlający warunki ruchu na skrzyżowaniu takiego typu. Przeanalizowano wpływ ruchu pieszego oraz pojemności powierzchni akumulacji w pasie rozdziału ulicy głównej na przepustowość pojazdów z wlotów podporządkowanych dołączających się do kolejki na jezdni głównej
EN
The box selectivity in operational stack of container terminal is a quite common and long studied question. The pure random choice is governed by the theory of probability offering some combinatorial estimations. The introduction of operational rules like import/export separation, storage by shipping lines, sorting by rail or truck transportation etc., as well as the most notorious ‘sinking’ effect, i.e. covering of boxes arrived earlier by next cargo parties – all these blur the clear algebraiс picture and lead to appearance of many heuristic outlooks of the problem. A new impetus to this problem in last decades was given by the rapid development of IT, AI and simulation techniques. There are quite many examples of the models described in the scientific publication reflecting many real and arbitrary terminals, which embed very advanced and complicated mechanisms reflecting selected features and strategies. Unfortunately, these models usually are created ad hoc, with some pragmatic objectives and under the demand of closest possible proximity to the simulating objects. There are much less models designated to pure scientific study of the deep inner mechanisms responsible for the primal behavior of the operating container stack, enabling to introduce step by step new rules and restrictions, providing regular proving of every next stage’s adequacy and easy to use. This paper describes one attempt of this kind to create a new theoretical tool to put into the regular toolkit of the container terminal designer. The study starts with mathematical (combinatorial) considerations, proceeds with some restrictions caused by physical and technological characteristics, and ends up with the simulation model, which adequacy is confirmed by practical results.
EN
At present, the simulation model of the electromechanical tap changer controller is not generally available. It is necessary in order to carry out tests of the voltage regulation system in the Main Supply Point (MSP). It is a lower voltage regulation system. The article presents simulation models of the tap changer controller working in a HV/MV station. The construction of all subsystems of the model is presented. Various methods of implementation of current compensation were also considered. The subsystems of the model and the whole have been simulated.
EN
Thai jewelry is the world’s leading jewelry which has gained high reputation and recognition from customers worldwide. In the past decade, jewelry have become one of the top ten export product of Thailand with the current export value of around 58,000 million baht per year which is 3.4 percent of all Thailand export products. Due to the high competition in the world market, however, Thai jewelry manufacturers needs to continue to improve their product quality as well as process efficiency in order to gain more market share. Currently, computer-aided tools have become more powerful tool in jewelry production management. They have been used to design production process, plant and workstation layout, production planning, worker’s scheduling, and other decisive decision making in both high management and shop floor levels. This research demonstrates a case study of plant simulation application for jewelry production process improvement. The objective is to reduce bottlenecks and increase productivity in wax pattern and casting processes using line balancing. Various scenarios have been proposed in order to support different level of desired output rate due to the increase of demand. The results of line balancing and simulation models reduce bottlenecks. Hence, productivity is increased. The desired throughput rates are achieved with the minimum number of workers and machine in the system.
EN
In the existent world of continuous production systems, strong attention has been waged to anonymous risk that probably generates significant apprehension. The forecast for net present value is extremely important for any production plant. The objective of this paper is to implement Monte Carlo simulation technique for perceiving the impact of risk and uncertainty in prediction and forecasting company’s profitability. The production unit under study is interested to make the initial investment by installing an additional spray dryer plant. The expressive values acquied from the Monte Carlo technique established a range of certain results. The expected net present value of the cash flow is $14,605, hence the frequency chart outcomes confirmed that there is the highest level of certainty that the company will achieve its target. To forecast the net present value for the next period, the results confirmed that there are 50.73% chances of achieving the outcomes. Considering the minimum and maximum values at 80% certainty level, it was observed that 80% chances exist that expected outcomes will be between $5,830 and $22,587. The model’s sensitivity results validated that cash inflows had a greater sensitivity level of 21.1% and the cash inflows for the next year as 19.7%. Cumulative frequency distribution confirmed that the probability to achieve a maximum value of $23,520 is 90 % and for the value of $6,244 it is about 10 %. These validations suggested that controlling the expenditures, the company’s outflows can also be controlled definitely.
PL
Współczesne organizacje funkcjonują w środowisku turbulentnym, które powoduje potrzebę wykorzystywania zaawansowanych technologii, a w tym m.in. systemów symulacyjnych, umożliwiających wcześniejszą ocenę sytuacji przy ustalonych ograniczeniach, jak również wariantowanie i wybór optymalnych rozwiązań. Bardzo duże znaczenie nabiera sprawność procesów logistycznych, które stają się główną determinantą ciągłości działania szczególnie w warunkach zaistnienia kryzysu i potrzeby utrzymania odpowiedniego poziomu bezpieczeństwa w dłuższym horyzoncie czasowym. Modele symulacyjne mogą więc sprzyjać doskonaleniu oraz usuwaniu prognozowanych luk w systemach logistycznych w różnych wymiarach zarządzania kryzysowego.
EN
Modern organizations operate in a turbulent environment that causes the need to use advanced technologies, including simulation systems, allowing for early assessment of the situation at set limits, as well as varianting and selection of optimal solutions. Very important is the efficiency of logistics processes, which become the main determinant of business continuity, especially in the conditions of crisis and the need to maintain an adequate level of security over a longer time horizon. Thus, simulation models can support the improvement and removal of forecast gaps in logistic systems in various dimensions of crisis management.
EN
World trends in the field of intellectualization and digitalization of all activity spheres, caused by the rapid growth of engineering and technology, have caused serious changes in the transport sector. Road transport has a negative impact on the environment, to a large extent this relates to city’s air pollution in urbanization conditions and the vehicle fleet accelerated growth. Reducing the negative vehicles impact on the environment is possible only through the development of integrated solutions for managing the transport system. Goal of this article is to study the applicability of decision support systems and simulation models to predict the possibility of reducing the negative vehicles impact on the environment. The developed simulation models for road network problem areas of the Naberezhnye Chelny city allow us to study the influence of traffic parameters on the volume of harmful substances in vehicles exhaust gases, as well as noise pollution. Using the model, it is also possible to assess the possible reduction in the degree of air pollution when converting engines public transport to natural gas fuel. Model experiments showed the adequacy of the proposed approach.
EN
The facility location problem is a popular issue in the literature. The current development of world economies and globalization of the market requires continuous improvement of methods and research in this field. The location of the object determines the time of transport, affects the operational costs of the supply chain, and determines the possible amount of inventory or minimum inventory levels. These are critical issues from the point of view of designing an effective logistics system. The degree of complexity of current decision-making problems requires the construction of mathematical models and support for the decision-maker by optimization and simulation methods. A comprehensive and systemic approach to the problem allows the effective planning of supply chains. The purpose of this article was to study the sensitivity of the warehouse location problem in the supply chain. The solution was obtained based on the methodology developed under the SIMMAG3D project. The article presents the characteristics of the issue of the location of warehouse objects, the mathematical formulation of the solved problem of location and the method of its solution based on the heuristic algorithm using the modification of the Busacker-Gowen method. Then, a supply chain simulation model was developed in the FLEXSIM environment and scenario studies were performed for various input data and model parameters. The analysis and assessment of the solution based on parameters such as utilization of the potential of warehouse objects object were presented. Random change in demand described by Erlang distribution and normal distribution was considered. The analysis showed how the selection of a statistical distribution to describe the input data can affect the shape of the logistics system. The article ends with a summary of considerations and a plan for further research in the use of the simulation environment to support the decision-making process of the location of storage facilities and the functioning of supply chains.
EN
This paper presents an original kinematic method for the assessment of the safe parameters of waterway bends. The proposed method has been based on the analysis of the results obtained through the use of the developed simulation model which allowed for the examination of all the physically available paths of a ship’s centre of gravity. The results of the simulation were divided into defined subsets that enabled the assessment of the safe parameters of waterway bends. This paper also presents the calculations that were carried out for the theoretical reference bend.
12
Content available Simulation model for maritime container terminal
EN
For logistic chains that have a maritime component, the ports transition involves a set of specific operations inside maritime container terminals. This can be cargo handling operations from the terrestrial vehicle in the storage area of ports, from port storage area in the maritime ships, as well as storage operations in the port area and other container terminal activities. Taking into consideration the multi-flow interactions and the non-uniform arrival of vessels and in-land vehicles, discrete event simulation stands as a feasible technique for investigating berthing capacity during the initial planning stage of the terminal or for operative planning of logistic processes at the terminal. If the storage area is analysed as a queuing system, the quality serving attributes could be evaluate. When different distributions for arrival flows of the containers in the maritime container terminal are taken into consideration, the quality serving attributes are difficult to estimate. In our paper, a discrete simulation model is developed in ARENA software for case of a maritime container terminal. The estimation of the general measures of performance for the container port terminals through simulation could provide data for the implementation in the management plans by port administrations.
EN
The aerodynamic noise of high-speed train power car was investigated in this article. The full-scale power car was first modeled, and the external steady flow field was computed by a realizable k-ε turbulence model. The aerodynamic noise sources of the power car surface and the external transient flow field were then calculated by broadband noise source model and large eddy simulation (LES) model, respectively. The static pressures on the train surface were obtained from the results of the transient model. Considering the transient flow field, the far-field aerodynamic noise generated by the power car was finally derived from Lighthill-Curle theory. It was validated by means of on-line tests that have been performed along a real high-speed railway line. Through comparisons between simulations and measurements, it is shown that the simulation model gives reliable aerodynamic noise predictions. We foresee numerous applications for modeling and control of the aerodynamic noise in high-speed train.
14
Content available Simulation Model of Container Land Terminals
EN
The simulation as a tool for the design of port and terminals has emerged as an answer for the demand to enhance the quality and reliability of the project results. Very high costs of the project solution implementation and practically total lack of liquidity of transport infrastructure objects always induced the immense commercial risks in the terminal business. Lately these risks have multiplied significantly due to rapid changes on the global and regional markets of transport services. Today, many experts come to see this volatility as an indicator of the next phase in development of the global trade system and the derivative cargo transportation system, specifically the state of temporal saturation. The shift of the global goods volumes from quick and steady growth to relatively small fluctuations around constant values causes quick oscillations in re-distribution of demand over the oversized supply. This new business and economic environment seriously affected the paradigm of transport terminal design and development techniques. The new operational environment of terminals put a request for the designers to arrange the results not in terms of “point”, but in terms of “functions”. Eventually it resulted in development of the modern object-oriented model approach. The wide spread of this approach witnesses the objective demand for this discipline, while in many aspects it remains in the intuitive (pre-paradigmal) phase of its development. The main reason for it is in the problem definition itself, which usually is formulated as the simulation of a given terminal. At the same time, the task is to assess the operational characteristics of the terminal engaged in processing of a given combination of cargo flows. Consequently, it is not the terminal that should be simulated, but the processes of cargo flows handling performed by this terminal under investigation. Another problem that restricts the practical spread of simulation is in the model adequacy. A model which adequacy is not proved has no gnoseological value at all. The paper describes the approach aimed at development of the models with the features discussed above.
PL
W pracy przedstawiono metodę opracowania modelu symulacyjnego układu sterowania piecem indukcyjnym z wykorzystaniem symulacji komputerowej w programie MATLAB®-Simulink. Zastosowano algorytmy regulatorów PID oraz pPI. Istotę działania modelu układu sterowania zilustrowano na schematach blokowych. Dokonano oceny jakości sterowania z wykorzystaniem wskaźników całkowych. Poddano analizie wyniki symulacji komputerowej modelu układu sterowania.
EN
The paper presents a method of development of a simulation model of the induction furnace control system, using a computer simulation in MATLAB®-Simulink program. Algorithms controls PID and pPI were used. The essence of the model of the control system is illustrated in the block diagrams. The quality of control was evaluated using integral indicators. Results of the computer simulation model of the control system were analyzed.
16
EN
Analysis of methods for demodulation of free induction decay signal that are suitable for use in pulsed nuclear quadruple resonance radiospectrometers was performed. The structure and MATLAB Simulink model of the receive path of radiospectrometer was synthesized, in which the Software Defined Radio technology was chosen for the implementation of a quadrature detector with a filtration and quadrature reflection suppression system. The application of the principle of direct digitization of the signal made it possible to significantly reduce the length of the analog portion of the receiver, and, consequently, reduce the noise of the useful signal and the level of out-of-band higher order spectral components.
PL
Przeprowadzono analizę metod demodulacji sygnału zaniku indukcji swobodnej, które są odpowiednie do stosowania w impulsowych radiospektrometrach jądrowego rezonansu kwadrupolowego. Opracowano strukturę i model ścieżki odbiorczej radiospektromeru w środowisku MATLAB Simulink, w którym do realizacji kwadraturowego detektora z układem filtracji i tłumienia odbicia kwadraturowego wybrano oprogramowanie Software Defined Radio. Zastosowanie zasady bezpośredniej cyfryzacji sygnału pozwoliło znacznie zmniejszyć długość analogowej części odbiornika, a w konsekwencji zmniejszyć szum sygnału użytecznego oraz poziom pozapasmowych składowych widmowych wyższych rzędów.
EN
In order to discuss the simulation model of the ship transmission line and the state of the transmission line, an early fault model is built according to the evolution principle of the short circuit fault of the transmission line and combining with the fault characteristics of the early fault. A small distributed ship transmission line system is built in MATLAB/ Simulink. Then, combined with the constructed fault module, the original short circuit module, and the load module, the various states (normal state, early fault state, severe early fault state, short circuit state) of the ship transmission line are stimulated, and the features of voltage signal in each state is analysed. It is concluded that, due to the normal operation of the ship transmission line system, the variation characteristics of the flow signal and voltage signal caused by the sudden load mutation, that is, the sudden load and the sudden increase load, are very similar to the changes caused by the early fault. Therefore, in order to find a more accurate early fault detection method, the state is divided into normal state, sudden load state, sudden increase and sudden decrease load state.
EN
This article presents the influence of aging processes of the electric vehicle’s electrochemical battery. The increasing number of hybrid and electric vehicles increases the demand for durable and efficient sources of energy storage for vehicles. The vehicle's declared range is reduced over time. This is due to the aging of the battery that causes loss of its capacity and loss of its power. To minimize this phenomenon, manufacturers use counteracting solutions that include mounting additional cells in the battery that are switched on when the battery controller identifies a particular battery cell’s failure or high degradation. This is due to the deep and shallow discharges of the battery, the number of charge and discharge cycles, and the age and technology of battery packs. AMESim software was used for the simulation of the electric vehicle. The research was based on modelling the range of the vehicle whose cell capacity includes processes related to aging of the battery. An aging cell algorithm causes the capacity to drop and consequently reduces the range of one full charge. By modelling aging processes, it is possible to determine the battery’s probable capacity loss during vehicle use and to estimate how these processes affect the vehicle's range.
19
Content available E-REV’s hybrid vehicle range modeling
EN
Article presents the influence of battery capacity and electric generator power on a series hybrid vehicle range. Vehicles equipped with increased battery capacity and small power generator are special type of series hybrid vehicles called Extended Range Electric Vehicles – E-REV. The increasing number of hybrid and electric vehicles increases the demand for durable and efficient sources of energy storage for vehicles. The hybrid vehicle's battery driven range is increased as battery power density is increased and its cost is decreased. This is due to the battery cell cost decreasing and improvement of cell chemistry. That cause higher and higher distance driven on electric mode in hybrid vehicles. First series hybrid vehicle engine power was equal to engine powered the vehicle’s wheels. Nowadays, series hybrid vehicles are more electric vehicles with small power generator (piston or turbine engine. In such a constructions, battery is used as an energy buffer and combustion engine is used more as emergency power supply. To minimize this phenomenon, manufacturers use counteracting solutions that include mounting additional cells in the battery that are switched on when the battery controller identifies a particular battery cell’s failure or high degradation. This is due to the deep and shallow discharges of the battery, the numbers of charging and discharging cycles, and the age and technology of battery packs. AMESim software was used for the simulation of the E-REV hybrid vehicle range. The research was based on modelling the range of the vehicle with different battery capacity works with power generator of different power. By modelling different capacity of battery and power of small generator, it is possible to determine the vehicle range.
EN
This paper presents different models and results of simulations of MEMS vibrating gyroscope in Matlab/SIMULINK environment. Each model is created with different approach, using different blocks and different physics. Therefore author presents his proposal of mathematical, electrical equivalent and physical models. Results obtained from these models can give some hints regarding design and dimensions of some crucial parts of MEMS gyroscope. Here, decoupled vibrating sensor is considered, which minimize drive and sense motion mutual influence.
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