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EN
This article discusses the proposed method for diagnosing diesel fuel equipment. An analysis of available methods for diagnosing fuel equipment has been carried out. The authors describe their method for diagnosing plunger pairs of a highpressure fuel pump according to the parameter of displacement of the injector needle. The design of the diagnostic device for measuring the movement of the injector needle has been developed and patented. The dependence of the maximum displacement of the injector needle on the increase, due to wear, of the radial clearance of the plunger bushing at the minimum steady state of idling of the engine has been determined. The technique of diagnosing the technical condition of plunger pairs of a high-pressure fuel pump by injector needle displacement is considered in detail.
EN
The paper presents the analysis of dynamic properties of pneumatic systems such as: cascade connection of membrane pressure transmitters and a pneumatic membrane actuator by means of differential equations of integer and non-integer order. The analyzed systems were described from the time perspective by means of step response, and in terms of frequency with the help of the Bode plot, i.e. logarithmic magnitude and phase responses. Each response was determined using differential equations of non-integer order. To determine the responses, the interactive Simulink package was an irreplaceable programming tool built on the basis of the MATLAB program, which enables the analysis and synthesis of continuous dynamic systems.
EN
The research addresses the problem of an ultra-large container ship mathematical model adjustment based on sea trials. In order to verify the model’s adequacy, simulated data had to be compared to the trial report data, which was obtained in ballast condition with significant trim. In such circumstances, model coefficients cannot be calculated by known methods and have to be corrected as per trial data. It is proposed to determine translational motion coefficients first. To get optimal results, it was also proposed to divide the objective function into kinematic and dynamic components, with each component being assigned a weighting factor. A separate objective function component was assigned to the zig-zag maneuver, which includes the first and second overshoot angles.
4
Content available remote Modelowanie matematyczne przepływu sprężonego powietrza przez filtr
PL
Stworzono model matematyczny pozwalający określić obniżenie ciśnienia sprężonego powietrza w urządzeniach i elementach odpowiedzialnych za utrzymanie odpowiedniej jakości powietrza (filtry powietrza). Model powstał na podstawie badań eksperymentalnych. Stwierdzono, że największy wpływ na zmianę ciśnienia w sieci przy przepływie przez filtr ma czas eksploatacji filtra oraz prędkość przepływu powietrza. Wiedza dotycząca korelacji tych parametrów pozwoli na odpowiedni dobór czasu eksploatacji filtrów i na optymalne projektowanie sieci pneumatycznej.
EN
Drop in compressed air pressure dependent on air flow rate and presence of filters and their operation time in a pipeline network was found. A math. model of the pressure drop was developed.
EN
The construction of a mill using the stator of an asynchronous motor as an inductor is a prototype construction. The article attempts to develop a mathematical model of an electromagnetic mill based on reluctance networks. It presents the kinds of raw materials shredded in this sort of mill as well as granulometric distribution of a quartz sand. The possibilities of using the device in other applications are also proposed.
PL
Konstrukcja młyna wykorzystująca w roli wzbudnika stojan silnika asynchronicznego jest konstrukcją prototypową. W artykule dokonano próby opracowania modelu matematycznego młyna elektromagnetycznego opartego o sieci reluktancyjne. Ponadto przedstawiono grupy surowców rozdrabnianych w tego rodzaju młynie oraz zaprezentowano rozkład granulometryczny dla piasku kwarcowego. Zaproponowano także możliwości wykorzystania urządzenia w innych zastosowaniach.
PL
Model matematyczny jest uproszczonym odwzorowaniem pewnych zjawisk, które uwzględnia jedynie cechy istotne. W dzisiejszych czasach coraz większym problemem stają się przeciążone infrastruktury drogowe, szczególnie w większych ośrodkach miejskich. Problem ten można w pewnym stopniu zredukować, stosując zaawansowane algorytmy sterowania. W niniejszym artykule podjęto próbę sterowania przepływem ruchu drogowego w skali makroskopowej. W tym celu użyto adaptacji dyskretnego, nieliniowego modelu matematycznego. Przy wykorzystaniu środowiska programistycznego MATLAB opracowano i zoptymalizowano układ sterowania niewielką siecią komunikacyjną. Następnie, zakładając przykładowy scenariusz, przeprowadzono dla tej sieci badania symulacyjne.
EN
The mathematical model is a simplified representation of certain phenomena, which takes into account only the essential features. Nowadays, congested road infrastructures are becoming a growing problem, especially in larger urban centres. This problem can be somewhat reduced by using advanced control algorithms. This article attempts to control the traffic flow on a macroscopic scale. For this purpose, a discrete, nonlinear mathematical model was adopted. Using the MATLAB programming environment, a control system for a small communication network was developed and optimised. Then, assuming a sample scenario, simulation studies were conducted for this network.
EN
To collect permeability data and establish its database of fertilizer nutrients and water vapor through different polymer membranes for the development of polymer-coated fertilizer, the permeabilities of N-, P-, and K-nutrient from saturated aqueous of urea, NaH2PO4 and KCl solution and the permeability of water vapor through the membranes of poly lactic acid (PLA), its blends with polystyrene (PS), and its composites with humic acid (HA) particles were determined experimentally at the temperatures of 288, 298, and 308 K, respectively. The effects of the addition of PS and HA particles, temperature, and coating thickness on the permeability of fertilizer nutrient and water vapor were investigated. It was found that the addition of PS and HA increased the permeability for both the fertilizer nutrients and water vapor. The increase in temperature raised the permeability of N-, P-, and K-nutrient while decrease the permeability of water vapor in the range studied.
8
Content available remote Model matematyczny do badań cieplnych dwubiegowych silników górniczych
PL
W silnikach indukcyjnych dwubiegowych przeznaczonych do pracy w podziemiach kopalń stosowane jest wodne chłodzenie kadłubów oraz tarcz łożyskowych. Z pomiarów cieplnych tego typu silników wynika, że w poszczególnych elementach konstrukcyjnych występują znaczne nierównomierności rozkładu temperatury. Najbardziej narażonymi na uszkodzenia termiczne elementami silnika dwubiegowego są uzwojenia stojana, w których przy znamionowym obciążeniu silnika różnica pomiędzy maksymalną a minimalną temperaturą (w zależności od mocy i typu silnika) osiąga wartość nawet kilkunastu °C. Stosowanie w obliczeniach projektowych [1, 5] tych silników uproszczonych modeli cieplnych, umożliwiających jedynie obliczenie średnich temperatur elementów, nie pozwala w pełni określić stopnia wykorzystania cieplnego poszczególnych jego elementów. Przeprowadzenie takiej oceny wymaga znajomości maksymalnych temperatur podstawowych elementów konstrukcyjnych silnika dwubiegowego w znamionowych warunkach zasilania i obciążenia.
EN
The paper presents a thermal model of two‑speed induction motors with water‑cooled frames. This model is made basing on the method of finite differences with the use of interpretation of the heat conduction equations in the form of thermal-electrical networks. It enables calculating temperature distributions in all constructional elements of induction motor and in the stream of water flowing in the frame as well as in the streams of air flowing in ventilation ducts of the rotor core and the frame. Basing on the model, a computer program that can be used for computer aided design is developed. Exemplary thermal calculations are carried out for the two-speed induction motor of 85/250 kW. The results obtained from simulations are compared with those from thermal measurements.
EN
The objective of the research is to find low cost alternative for conventional recreational lagoons that consume water and energy used for desalination which is the only alternative for water treatment in most touristic villages all over the world. The study uses low cost recreational lagoon with new technology that use brackish water from deep wells and purify this water before entering the lagoon by controlled pulses and energyefficient ultrasound filtration. This allows to maintain the water within predefined parameters, guaranteeing standardized water quality in all lagoons. The research introduces the lagoon new technology and its low cost design including feeding and drainage wells, second, the hydrographic surveying for the coastline in the study area, third water quality modelling for the production and injection wells, fourth, use SOBEK 1-2 Mathematical Model for determine the water depth and perspective water volume for the designed lagoon. The aim of this model: Determine the relation between the water depth and the water volume for the canal and the lakes. Second, calculate the evaporation rate from the surface, Determine the number and capacity of the water wells needed to fill the canal and the lakes, and Find out the relationship between the discharge and the time needed to circulate the water in the canal and the lakes to keep their water quality. The results of the measurements from the observation well prove that the optimal discharge per each well is 0.022 m3·s–1. The construction of suggested new green technology lagoon are very low cost, completely environmentally friendly, in addition fulfils the highest standards of environmental safety.
EN
For military equipment products maintained according to the condition-based operation strategy with control of parameters a mathematical model is constructed using semi-Markov random process. The diffusion-monotonic distribution law which is inherent in mechanical type products is taken for the fault model. The model takes into account type I errors. The analytical dependence of the utilization factor on the parameters of the scale and shape of the diffusion-monotonic distribution, the of regulated maintenance periodicity, the duration of complete restoration of a sample of equipment, the reliability of its control, is established. Graphs of the dependence of the utilization factor on the given parameters of the model are shown.
PL
Model matematyczny wykorzystujący losowy proces semi-Markowa został opracowany dla wyrobów sprzętu wojskowego obsługiwanych zgodnie ze strategią eksploatacji według stanu z kontrolą parametrów. Dla modelu uszkodzenia przyjęto prawo podziału dyfuzyjno-monotonicznego właściwego dla wyrobów mechanicznych. Model uwzględnia błędy pierwszego rodzaju. Ustalono analityczną zależność współczynnika wykorzystania technicznego od parametrów skali i kształtu rozkładu dyfuzyjnomonotonicznego, okresowości przeprowadzenia obsługiwania planowego, czasu trwania pełnej regeneracji próbki sprzętu, niezawodności jego kontroli. Pokazano wykresy zależności współczynnika wykorzystania technicznego od danych parametrów modelu.
EN
The authors determined the accuracy and reliability of yielding models by using the values of two differently obtained indices – the leaf area index (LAI) obtained through direct surface measurements, and the normalized difference vegetation index (NDVI) obtained through spatial remote sensing of crops. The study based on the drip-irrigated sweet corn yielded the data obtained in the field experiment held in the semi-arid climate on darkchestnut soil in the South of Ukraine. The suitability of the LAI and NDVI for the simulation of sweet corn yields was estimated by the regression analysis of the yielding data by correlation (R) and determination (R2) coefficients. Additionally, mathematical models for the crop yields estimation based on the regression analysis were developed. It was determined that LAI is a more suitable index for the crop yield prediction: the R2 value was 0.92 and 0.94 against 0.85 for the NDVI-based models.I It was determined that it is better to use the LAI values obtained at the stage of flowering, when R2 averaged to 0.94, and the NDVI-based models does not depend on the crop stage (the R2 was 0.85 both for the flowering and ripening stages of the plant development). The combined NDVI-LAI model showed that there is no necessity in the complication of the LAI-based model through introduction of the remotely sensed index because of insignificant improvement in the performance (R2 was 0.94 and 0.92).
EN
The balance calculations in agriculture are the basis for assessing the value of land and determining how to use it effectively. Replenishing the humus balance in soils is a long and multifactorial process, and therefore requires considerable expenditures to control it. Therefore, scientists pay particular attention to the benefits and the need to create geoinformation portals, first and foremost, in the agricultural sector in order to create effective market-based tools for balancing soil quality. However, today Ukraine has little experience in creating portals and software for the implementation of soil fertility balance calculations in the online system for the purpose of organizing organic land use. The article deals with the methods of humus balance calculation and the formulation of the humus balance calculation task, which will take into account regional peculiarities of Ukraine’s Rivne region with the possibility of scaling to other areas. A mathematical model of the corresponding problem using differential equations was constructed. A numerical solution was found and implemented as the e-calculator module of online information system. The integration of IT technologies with the example of humus balance e-calculator for organic land use will allow crop rotations modeling and volumes of organic fertilizer application to stabilize or improve the soil quality. The main task of the calculator was to provide specific recommendations for the land plot on the efficiency of its use. In addition, the information system provided the background information on the economic efficiency of the transition to organic farming, certification, processing and marketing rules. The user can independently specify the order of crops cultivation in rotation, the amount of organic fertilizer application and as a result will receive the possible variants of the total humus content in the soil, for different volumes of application of organic fertilizers (biohumus) using the e-calculator of humus balance. The testing and verification of the e-calculator was carried out on the last 40 years data of the Rivne branch of the Soils Protection Institute of Ukraine, taking into account the cultivated crops, the introduction of mineral and organic fertilizers.
EN
The subject of the paper is the Bialystok water supply network. The studies on the Bialystok water supply network are aimed at identifying new, more rational ways of operation (decreasing the pressure value) and defining the conditions for expansion and modernization of the water supply network, with the particular system analysis as a part of identifying the most dangerous places on the network. The increase of requirements concerning the quality and the time of realisation in the scope of the design studies requires the introduction of computer technology in calculations. The work presents the processes based on mapping and refinement of specific conservative states of the water distribution system (SDW), using mathematical modelling taking into account the latest available computer techniques.
EN
The concept of innovative educational environment of higher education establishment is considered and its main components are highlighted. The model of the integrated assessment of implementing innovations in higher education establishment is constructed. The developed model for assessing the level of development of the innovative educational environment of a specific higher education establishment during a certain period has been applied and a graphical analysis of the calculation results has been carried out.
EN
Today in woodworking, there are problems with the use of wood waste and the accumulation of involved wood as an additional and not fully used resource. The problem has not been completely solved, as there is no scientific basis and practical recommendations for efficient production processes with predicting the properties of products made from Post-Consumer Wood (PCW), in particular in the production of blockboards (BB). The objective of the studies is to substantiate and develop a scientific and technical basis for resource-saving and environmentally friendly technologies, to establish the influence patterns of PCW properties on the mechanical characteristics of the products obtained, to develop operating parameters and to formulate practical recommendations, confirmed by the results of experimental studies. The studies have proved the expediency of using PCW in technological processes of woodworking, in particular in the production of construction materials - blockboards with predicted characteristics. In order to rationally use raw materials for the manufacture of conventional blockboards made from Post-Consumer Wood (PCW-BB), new designs of a conventional PCW blockboard with a thickness of 22 mm and with a unified strip width of 16, 32, 48, and 64 mm, the strips are glued ones, 3 mm thick, and faced with plywood on both sides. The authors of the article found that in order to ensure improved operating characteristics of the blockboards, it is important to lay radial, semi-radial and tangential strips in structures with the ratio of width to thickness of the cross-sections of the strips - rationally and efficiently - 1:1, 2:1, 3:1. Substantiation on this basis of new designs of PCW blockboards makes it possible to reveal shortcomings of these products at the conceptual stage of the project and correct them before manufacturing taking into account the specified technical conditions and reducing costs at the development stage. Mathematical models for predicting the main characteristics of conventional PCW blockboards (PCW-BB) have been constructed, which made it possible to determine the indexes of the bending strength of the BB across the strips, σBB, and the shear strength of the BB along the glue line, τВВ. The coefficients of approximation of mathematical dependencies for predicting the strength of PCW-BBs, the strips of which were made of fir wood, were calculated, which would allow for the selection of rational designs of blockboards with appropriate characteristics. It has been established that the developed mathematical models make it possible to predict the characteristics of the PCW-BB depending on the cross-sectional dimensions of the strips, the angle of the annual rings slope to the blockboard face and the age of the PCW, and, on this basis, to propose improved designs of these blockboards for the technological processes of woodworking. The influence patterns of the properties of structural elements on the indicators of conventional PCW-BB (500 × 500 × 22 mm) were experimentally established. It was found that an increase in the width of the strips leads to a decrease in the strength indexes (by 29-37%); an increase in the angle of the annual rings slope to the BB face leads to an increase in static bending strength (by 31-33%) but to a decrease in shear strength (by 4-7%); an increase in the age of the PCW leads to a decrease in strength indexes (by 3-8%). It was found that the physical and mechanical parameters of the experimental PCW-BBs with a strip cross-sections of 1:1, 2:1, 3:1 meet the requirements of the standard (larger values: for static bending of a rate of 15 MPa and for shearing at a rate of 1 MPa), and for the 4:1 cross- -section, they partially had lower indexes by 2-3%. To ensure the strength of the developed structures of the PCW-BBs, it is recommended to use the 3:1 ratio of the sides in the cross-section of the strips, and the slope of the annual rings to the blockboard face must be at least 45o. It was found that the deviation of the values obtained by mathematical models in determining the strength in static bending and shearing in comparison with the experimental ones did not exceed 8% and 10%, respectively.
PL
W artykule przedstawiono wyniki oryginalnego badania, w którym przeanalizowano współczynnik przenoszenia ciepła fragmentu ściany z oknem z PVC z zewnętrzną osłoną przeciwsłoneczną w zależności od: typu osłony, scharakteryzowanego wartością dodatkowego oporu cieplnego wynikającego z zastosowania osłony, pola powierzchni okna, sposobu połączenia szyby z ramą, scharakteryzowanego wartością liniowego współczynnika przenikania ciepła mostka termicznego powstającego na granicy szyba-rama oraz współczynników przenikania ciepła oszklenia i ramy. Zbiór danych do analizy uzyskano przy realizacji eksperymentu obliczeniowego. Analiza wykonana została na podstawie opracowanego deterministycznego modelu matematycznego opisującego tę zależność. Informacja może być przydatna dla projektantów, naukowców, producentów i konsumentów stolarki okiennej.
EN
The article presents the results of the original study, which analysed the heat transfer coefficient of a wall fragment with a PVC window with an external sun visor depending on the type of cover, characterized by the value of additional thermal resistance resulting from the use of a cover, the window surface area, the way the glass is connected to the frame, characterized by the value of linear heat transfer coefficient of thermal bridge generated at the glass-frame border, as well as the heat transfer coefficients of the glazing and the frame. The data set for analysis was obtained during the implementation of the computational experiment. The analysis was made based on the developed deterministic mathematical model describing this relationship. Information can be useful for designers, scientists, producers and consumers of windows.
RU
Razrabotana matematičeskaâ model’ processa èlektrokontaktnogo spekaniâ ÈKS) tverdosplavnyh kompozicij pri izgotovlenii pravâŝih fil’er stroitel’noj armatury. Model’ pozvolâet rassčitat’ uplotnenie pressovki, diagrammu poslojnogo raspredeleniâ plotnosti, diagrammy polej temperatur i davlenij, raspredelenie plotnosti toka po sečeniû pressovki i egoizmenenie v zavisimosti ot otnositel’noj plotnosti. Aprobirovannye v modeli analitičeskie zavisimosti rasprostraneny na proizvol’nuû geometriû fil’er pri pomoŝi konečno-èlementnogo modelirovaniâ s korrektirovkoj svojstv materiala po analitičeskim zavisimostâm, ishodâ iz plotnosti pressovki. Ocenka adekvatnosti modeli provedena po krivoj pressuemosti. Rezul’tatami rasčetov dokazan i èksperimental’no podtveržden èffekt sniženiâ termobaričeskih parametrov kompaktirovaniâ spekaemoj tverdosplavnoj kompozicii pri ee modificirovanii termoaktiviruûŝej dobavkoj, blagodarâ čemu povyšena stojkost’ keramičeskih press-form i na 40% snižen procent koničeskoj poverhnosti zagotovki fil’ery.
EN
A mathematical model of the process of electrocontact sintering of carbide compositions in the manufacture of straightening dies of construction fittings has been developed. The model allows to calculate the compression of the compact, the diagram of the layer-by-layer density distribution, the diagrams of temperature and pressure fields, the distribution of current density over the cross-section of the compact and its change depending on the relative density. The analytical dependences, tested in the model, are extended to arbitrary geometry of the dies, using finite element modeling with adjustment of material properties according to analytical dependencies, based on the density of pressing. An assessment of the adequacy of the model was carried out by the compressibility curve. The results of calculations proved and experimentally confirmed the effect of reducing the thermobaric parameters of compacting the sintered carbide composition, when it is modified with a thermosetting additive, which increased the resistance of ceramic molds and reduced the percentage of rejects by 40%. The tensile radial deformations along the conical surface of the die blank are predicted.
EN
The paper dwells on a mathematical model of the logistical system of transport services for persons with disabilities, and there have been analyzed factors that affect the time spent on their transportation. When developing methodology for optimizing the time costs of passenger transport of persons with disabilities, the following two basic transportation services have been taken into account: (a) "social taxi", which will transport only people with special health; (b) a vehicle system in combination with urban passenger transport, which will transport representatives of the group of people with restricted mobility together with all other passengers. The study found that in the case of insufficient accessibility to the required environment, by the increase in the demand of disabled people for transportation by "social taxi", travelling costs are increased that results in increasing total costs of the carrier. Based on a comparative analysis of logistical costs, optimum relationship between the number of the adapted buses and “social taxi” on the route under study has been established.
EN
The purpose of this paper is to describe and analyse a mechanical device designed to enhance the safety of a motor vehicle. The topic is addressed by analysing the method of absorbing kinetic energy during a car collision with an obstacle. The article analyses opportunities to convert motor vehicle’s kinetic energy into another type of energy in the case of collision. For this purpose, various mechanical, hydraulic or pneumatic devices are normally used. Such devices are designed to absorb collision energy and reduce or eliminate its impact on the driver, the passengers or cargo in the motor vehicle. The absorber may be used as an additional element of safety to the passenger and the cargo. The energy absorber described in the present article incorporates hydraulic, pneumatic and mechanical components. The description of the absorber presented here is based on mathematical calculations characterizing mechanical, pneumatic and hydraulic processes in the equipment. The analysis of the developed mechanism employs a special application to calculate major parameters of the motor vehicle and the installed absorber. The article also gives a sensitivity analysis of the effect of the rod length on the decrement of the vehicle's kinetic energy.
EN
A smart solution for assessing the consequences of pollution on the coast, on flora and fauna but also by accounting for the total costs of the equipment used in the response to pollution is a system for assessing, coordinating and simulating the risk situation with the help of a mathematical model implemented on a simulator. The mathematical model for the simulation of the event of pollution is the latest generation and take into account all the meteorological factors of the sea and air, as well as all the physico-chemical parameters of the substances involved (dispersion, surface tension). The simulator is used for the realistic modeling of a crisis situation and it is useful for both marine officers and emergency situation officials. The simulator will be used as an educational instrument enabling the interactive study of the different emergency situations. In this paper we present the simulation of incident and the creation of response resources. The scenario incident is for KAPTAN M cruise ship that left the tourist port of TOMIS Constanta, Romania, having on board 20 passengers and a number of 15 crew members, and which collided with the oil ship EVIA Oil FIVE, having on board the quantity of 4200 MT crude oil. As a result of the collision, the passenger ship suffered a breach (water hole), on the starboard board, breach by which the ship began to ambarce sea water and in the car compartment a fire was produced. Containment and recovery of an oil spill during the exercise will be simulated through activation and control of response resources. The resources involved in the operations are divided into: platforms, equipment and personnel. The results of simulation is the list of response resources specified in the scenario together with their parameters, which can be exported into a text file. With this simulation tools you can efficiently appreciate the cost of resources in due time, avoiding material and human damage.
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