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Polohovací systém pro měřicí hlukové mikrofony / Positioning system for noise measuring microphonesPulec, Václav January 2011 (has links)
The thesis deal with programing of algorithm for creating measuring box composed of measuring points. Coordinates of these points will be used for planing trajectory of the robot’s effector. It describes construction of structural model in Solid Works and calculate dynamic model by matrix formalism in MATLAB. In conslusion dynamic model of positioning system is used for the choice of appropriate motors.
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Výpočet průhybu hřídele elektrického stroje zahrnující vliv magnetického tahu / Programme for calculation of electric machine shaft deflection caused by magnetic tractionKukačka, Radek January 2014 (has links)
This Master thesis desires the design of methodology for calculating shaft deflection and critical speed of electric machines. There are two methods used. The first one is transfer matrix method, which is represented by a simple programme for shaft creation and calculating needed results built in the Matlab software. The second one is finite element method, which is presented in the Ansys Workbench software.
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Řešení diferenčních rovnic a jejich vztah s transformací Z / Solution of difference equations and relation with Z-transformKlimek, Jaroslav January 2011 (has links)
This dissertation presents the solution of difference equations and focuses on a method of difference equations solution with the aid of eigenvectors. The first part reminds the basic terms from area of difference equations such as dynamic of difference equations and linear difference equations of first order and higher order. Then the second section recalls also the system of difference equations including the fundamental matrix and general solution description. Afterthat, the method of solving the difference equations with a variation of constants and transform of scalar equations to the system are shown. The second part of the dissertation analyses some known algorithms and methods for the solution of linear difference equations. The Z-transform, its importance and usage for finding the solution of difference equation is recalled. Then the discrete analogue of Putzer's algorithm is mentioned because this algorithm was often used to check the results obtained by the newly described algorithm in further parts of this thesis. Also some ways of the system matrix power are stated. The next section then describes the principle of Weyr's method which is the basic point for further development of the theory including the presentation of the research results gained by Jiří Čermák in this area. The third part describes own solution of the difference equations system via eigenvectors based on the principle of Weyr's method for differential equations. The solution of system of linear homogeneous difference equtions with constant coefficients including the proof is presented and this solution is then extended to nonhomogeneous systems. Consequently to the theory, the influence of a nulity and the multiplicity of roots on the form of the solution is discussed. The last section of this part shows the implementation of the algorithm in Matlab program (for basic simpler cases) and its application to some cases of difference equations and systems with these equations. The final part of the thesis is more practical and it presents the usage of the designed algorithm and theory. Firstly, the algorithm is compared with Z-transform and the method of variation of constants and it is illustrated how to obtain the same results by using these three approaches. Then an example of current response solution in RLC circuit is demonstrated. The continuous case is solved and then the problem is transferred to discrete case and solved with the Z-transform and the method of eigenvectors. The obtained results are compared with the result of the continuous case.
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Transfer Path Analysis of a Passenger CarCinkraut, Jakub January 2015 (has links)
Even though there are no regulations on the interior noise level of passenger cars, it is a significant quality aspect both for customers and for car manufacturers. The reduction of many other car noise sources pushed tyre road noise to the forefront.What is more, well known phenomenon of the tyre acoustic cavity resonance (TCR), appearing around 225 Hz, makes the interior noise noticeably worse. Some techniques to mitigate this phenomenon right at the source are discussed in this thesis, however, these has not been adopted by the tyre nor car manufacturers yet.Therefore, there is a desire to minimise at least the transmission of the acoustic or vibration energy from the tyre to the compartment. This is where methods like TPA (Transfer Path Analysis) come into play.In this thesis, two different approaches to TPA are used to investigate transmission of the TCR energy.First, the coherence based road decomposition method is used to determine whether the TCR energy is transmitted by a structure-borne or an air-borne mechanism. The same method serves to identify if the TCR noise comes mainly from the front or the rear suspension.Second, the impedance matrix method was used to determine critical structure-borne transfer paths yielding clear results indicating two critical mounts at the rear suspension which dominate the transfer of vibro-acoustic energy. Subsequent physical modification of the critical mount was tested to verify the results of the transmission study.Moreover, deflection shape analysis of the tyre, rim, front and rear suspension was performed to identify possible amplification effects of the TCR phenomenon.
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Teorijska i eksperimentalna analiza dinamičkog ponašanja jezgra visokih zgrada / Theoretical and experimental analysis of the dynamic behaviour of the tall buildings coreVarju Đerđ 12 September 2016 (has links)
<p>U ovoj disertaciji, izvršena su teorijska i eksperimentalna istraživanja dinamičkog onašanja jezgra visokih zgrada. Model je zasnovan na Vlasovoj teoriji tankozidnih nosača, kao i na metodi prenosnih matrica. Jezgro se tretira kao tankozidni nosač otvorenog poprečnog preseka, koji je na dnu uklješten u temeljnu ploču, dok je na vrhu slobodan. Duž ose smicanja, jezgro je podeljeno na čvorove u nivoima spratova u kojima su redukovane mase. Poseban naglasak je stavljen na analizu uticaja poprečnih greda, međuspratnih ploča, kao i načinu oslanjanja međuspratnih ploča po spoljašnjoj konturi na dinamičke karakteristike jezgra. Razvijeni numerički postupak je primenjen na armiranobetonskom jezgru petnaestospratne zgrade, koja je analizirana ranijeu radovima mnogih autora. U tu svrhu korišćen je računarski program TWBEIG, napisan primenom Visual Fortran programskog jezika. Analize su urađene i MKE, a dobijeni rezultati su upoređeni. Vrednosti sopstvenih frekvencija pokazuju dobro slaganje.<br />Ovaj rad daje detalje i o eksperimentalnoj studiji u kojoj se primenjuje pleksiglas model u cilju pružanja eksperimentalnih podataka zaproveru tačnosti i pouzdanosti numeričkih rezultata. Dobijeni rezultati su takođe upoređeni sa rezultatima dobijenim TWBEIG računarskim programom, kao i MKE.<br />Predstavljeni numerički metod nudi solidnu osnovu za formiranje jednostavnog modela proračuna, a ipak obezbeđuje odgovarajući nivo preciznosti. Predloženi postupak može biti korišćen i u fazi prethodne analize zgrade, kao i u fazi konačnog projektovanja.</p> / <p>In this dissertation, a theoretical and experimental study of the dynamic behaviour<br />of the tall buildings core was carried out. The model is based on the Vlasov's<br />theory of thin-walled beams and the transfer matrixmethod. The core is treated as<br />a thin wall-walled, open cross section cantilever beam. Along the shear axis the<br />core is divided into nodes, in the level of the floors, in which the masses are<br />reduced. Special emphasis was given to the analysis of the influence, of lintel<br />beams, floor slabs, as well as the type of restraints along the outer edge of the<br />floor slabs, on the dynamic characteristics of the core.<br />The developed numerical procedure was applied to the fifteen-storey reinforced<br />concrete core tall building, analyzed previously inthe papers of many authors. For<br />this purpose, the computer program TWBEIG was used, written using Visual<br />Fortran programming language. The analyses were also performed with FEM and<br />subsequently the results were compared. The values of natural frequencies show<br />significant agreement. This paper presents details about the experimental study which applies the plexiglas model in order to provide experimental data to verify the accuracy and reliability of the numerical results. The results are also compared with the results obtained with the TWBEIG computer program, as well as with FEM. The values of frequencies show reasonable agreement.<br />The proposed numerical method offers a solid base for the creation of a simple<br />calculation model, yet provides the appropriate level of precision. It can be either<br />used for preliminary analysis or for the final design.</p>
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Development of Novel Green’s Functions and Their Applications to Multiphase and Multilayered StructuresHan, Feng 05 October 2006 (has links)
No description available.
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Оценка эффективности управления персоналом на металлургическом предприятии : магистерская диссертация / Evaluation of the effectiveness of personnel management in a metallurgical plantСилкина, А. С., Silkina, A. S. January 2019 (has links)
В научных работах практически не рассматриваются взаимосвязь управления знаниями и управления персоналом, следовательно, не уделяется должного внимания разработке инструментария для решения проблемы эффективного управления предприятием с использованием данной взаимосвязи. Отсутствие методик оценки эффективности управления персоналом с учетом взаимосвязи управления персоналом и управления знаниями, а также с учетом особенностей и специфики металлургических предприятий вызывает необходимость анализа современного состояния управления персоналом на промышленных предприятиях, что определило постановку цели, задач данного исследования. Целью магистерской диссертации является разработка методики оценки эффективного управления персоналом на металлургическом предприятии для обеспечения конкурентоспособности металлургического предприятия. Разработана методика оценки эффективности управления персоналом, базирующаяся на взаимосвязи профессионально-значимых качеств персонала и управления знаниями, особенностью которой является применение матричного метода к оценке процессов управления персоналом, оказывающих наибольшее влияние на управление и позволяющая принимать обоснованные управленческие решения. Главным преимуществом предложенной методики является применение матричного метода к оценке процессов управления персоналом. Для обеспечения эффективного взаимодействия между управлением персоналом и управлением знаниями, предложен подход к определению соответствия профессионально-значимых качеств персонала требованиям профессий и должностей. / In scientific works practically the interrelation of knowledge management and personnel management is not considered, therefore, due attention is not paid to development of tools for the solution of a problem of effective management of the enterprise with use of this interrelation. The lack of methods for assessing the effectiveness of personnel management, taking into account the relationship of personnel management and knowledge management, as well as taking into account the characteristics and specifics of metallurgical enterprises, necessitates the analysis of the current state of personnel management in industrial enterprises, which determined the goal and objectives of this study. The purpose of the master's thesis is to develop a methodology for assessing the effective management of personnel at the metallurgical enterprise to ensure the competitiveness of the metallurgical enterprise. The method of personnel management efficiency assessment based on the relationship of professionally significant qualities of personnel and knowledge management, the feature of which is the application of the matrix method to the assessment of personnel management processes that have the greatest impact on management and allow to make informed management decisions. The main advantage of the proposed method is the use of the matrix method to assess the processes of personnel management. To ensure effective interaction between personnel management and knowledge management, an approach is proposed to determine the compliance of professionally significant qualities of personel with the requirements of professions and positions.
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Dynamic Credit Models : An analysis using Monte Carlo methods and variance reduction techniques / Dynamiska Kreditmodeller : En analys med Monte Carlo-simulering och variansreducreingsmetoderJärnberg, Emelie January 2016 (has links)
In this thesis, the credit worthiness of a company is modelled using a stochastic process. Two credit models are considered; Merton's model, which models the value of a firm's assets using geometric Brownian motion, and the distance to default model, which is driven by a two factor jump diffusion process. The probability of default and the default time are simulated using Monte Carlo and the number of scenarios needed to obtain convergence in the simulations is investigated. The simulations are performed using the probability matrix method (PMM), which means that a transition probability matrix describing the process is created and used for the simulations. Besides this, two variance reduction techniques are investigated; importance sampling and antithetic variates. / I den här uppsatsen modelleras kreditvärdigheten hos ett företag med hjälp av en stokastisk process. Två kreditmodeller betraktas; Merton's modell, som modellerar värdet av ett företags tillgångar med geometrisk Brownsk rörelse, och "distance to default", som drivs av en två-dimensionell stokastisk process med både diffusion och hopp. Sannolikheten för konkurs och den förväntade tidpunkten för konkurs simuleras med hjälp av Monte Carlo och antalet scenarion som behövs för konvergens i simuleringarna undersöks. Vid simuleringen används metoden "probability matrix method", där en övergångssannolikhetsmatris som beskriver processen används. Dessutom undersöks två metoder för variansreducering; viktad simulering (importance sampling) och antitetiska variabler (antithetic variates).
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Développement d'une méthode hybride éléments finis-matrice de transfert pour la prédiction de la réponse vibroacoustique de structures avec traitements acoustiques / Development of a hybrid finite element-transfer matrix methodology for the modeling of vibroacoustic systems with attached noise control treatmentsAlimonti, Luca January 2014 (has links)
Résumé : Les véhicules aériens et terrestres sont constitués de systèmes bâtis complexes. La structure principale est généralement composée de panneaux légers renforcés par des éléments rigides. Cette solution de conception est répandue parce qu’elle allie la force et un faible poids. Cependant, on sait qu’elle offre des résultats vibroacoustiques médiocres, c’est à dire que l’effet des perturbations externes qui touchent le système peut générer un niveau de bruit excessif à l’intérieur de la cabine des passagers. C’est une préoccupation majeure chez les fabricants, parce que ce niveau de bruit nuit sensiblement au confort ressenti par les clients et peut causer de la fatigue chez les conducteurs et les pilotes. Pour cette raison, les composants passifs constitués de matériaux dissipatifs assemblés en mode multicouche sont généralement intégrés à la structure. Ces assemblées bordées intègrent surtout des matériaux poroélastiques, qui sont plutôt répandus, grâce à l’agencement intéressant de bonnes propriétés d’isolation sonore et de faible poids.
L’intégration en amont des traitements de contrôle du bruit au processus de conception
est la clé de succès d’un produit. Pour ce faire, des outils pratiques numériques en mesure de capter le comportement dynamique des systèmes vibroacoustiques impliquant les structures, les cavités et les matériaux d’insonorisation sont requis. D’une part, la modélisation de ces systèmes couplés en utilisant des procédés à base d’éléments finis peut être, bien que précis, irréalisable pour des applications pratiques. D’autre part, les approches analytiques telles que la méthode de matrice de transfert sont souvent préférées grâce à leur facilité d’utilisation, même si elles manquent de précision en raison des hypothèses rigoureuses inhérentes au cadre analytique. Dans ce contexte, les procédures de structuration hybrides sont récemment devenues très populaires. En effet, les différentes techniques de modélisation sont généralement recherchées pour décrire les systèmes vibroacoustiques complexes arbitraires sur la plus large gamme de fréquences possible.
L’objectif du projet proposé est de mettre au point un cadre hybride offrant une mé-
thodologie simple pour tenir compte des traitements de contrôle du bruit dans l’analyse
vibroacoustique par éléments finis. A savoir, le modèle de calcul qui en découle conserve la souplesse et la précision de la méthode des éléments finis en bénéficiant de la simplicité et de l’efficacité de la méthode de matrice de transfert pour obtenir une réduction de la charge de calcul pour la modélisation de composants acoustiques passifs. La performance de la méthode pour prédire la réponse vibroacoustique de structures planes homogènes avec des traitements acoustiques attachées est évaluée. Les résultats démontrent que la méthode hybride proposée est très prometteuse, parce qu’elle permet une réduction de l’effort de calcul tout en conservant suffisamment de précision par rapport à l’analyse complète par éléments finis. En outre, la méthode de matrice de transfert proposée de modélisation des traitements de contrôle des bruits est générale, comme on peut l’appliquer dans d’autres cadres outre l’application de l’élément fini considéré dans ce travail. // Abstract : Aerial and terrestrial vehicles consist of complex built-up systems. The main structure is typically made of light panels strengthened by stiffer components. Such design solution is widely used as it combines strength and low weight. However, it is known to give poor vibroacoustic performances, i.e. the effect of external disturbances acting on the system may generate an excessive noise level inside the passengers cabin. This is a main concern for the manufacturers, as it significantly affects the comfort experienced by the costumers and may fatigue drivers and pilots. For this reason, passive components consisting of dissipative materials assembled in a multilayer fashion are typically integrated within the structure. These lined assemblies mainly involve poroelastic materials, which are commonly used thanks to the appealing combination of good noise insulation properties and low weight.
The early integration of noise control treatments in the design process is the key to a successful product. For this purpose, practical numerical tools able to capture the dynamic behavior of vibroacoustic systems involving structures, cavities and noise proofing materials are demanded. On the one hand, modeling such coupled systems using finite element based methods can be, albeit accurate, time consuming for practical applications. On the other hand, analytical approaches such as the transfer matrix method are often preferred thanks to their ease of use, although they suffer from a lack of accuracy due to the stringent assumptions inherent within the analytical framework. In this context, hybrid substructuring procedures have recently become quite popular. Indeed, different modeling techniques are typically sought to describe arbitrarily complex vibroacoustic systems over the widest possible frequency range.
The aim of this thesis is to devise a hybrid framework providing a simple methodology to
account for noise control treatments in vibroacoustic finite element analysis. Namely, the
resulting computational model retains the flexibility and accuracy of the finite element
method while taking advantage from the simplicity and efficiency of the transfer matrix
method to obtain a reduction of the computational burden in the modeling of passive
acoustic components. The performance of the method in predicting the vibroacoustic
response of flat structures with attached homogeneous acoustic treatments is assessed.
The results prove that the proposed hybrid methodology is very promising, as it allows for a reduction of the computational effort while preserving enough accuracy with respect to full finite element analysis. Furthermore, the proposed transfer matrix based methodology for noise control treatments modeling is general, as it can be used in alternative frameworks besides the finite element application considered in this work.
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以最小平方法處理有限離散型條件分配相容性問題 / Addressing the compatibility issues of finite discrete conditionals by the least squares approach李宛靜, Lee, Wan Ching Unknown Date (has links)
給定兩個有限離散型條件分配,我們可以去探討有關相容性及唯一性的問題。Tian et al.(2009)提出一個統合的方法,將相容性的問題轉換成具限制條件的線性方程系統(以邊際機率為未知數),並藉由 l_2-距離測量解之誤差,進而求出最佳解來。他們也提出了電腦數值計算法在檢驗相容性及唯一性時的準則。
由於 Tian et al.(2009)的方法是把邊際機率和為 1 的條件放置在線性方程系統中,從理論的觀點來看,我們認為該條件在此種做法下未必會滿足。因此,本文中將邊際機率和為 1 的條件從線性方程系統中抽離出來,放入限制條件中,再對修正後的問題求最佳解。
我們提出了兩個解決問題的方法:(一) LRG 法;(二) 干擾參數法。LRG 法是先不管機率值在 0 與 1 之間的限制,在邊際機率和為 1 的條件下,利用 Lagrange 乘數法導出解的公式,之後再利用 Rao-Ghangurde 法進行修正,使解滿足機率值在 0 與 1 之間的要求。干擾參數法是在 Lagrange 乘數法公式解中有關廣義逆矩陣的計算部份引進了微量干擾值,使近似的逆矩陣及解可快速求得。理論證明,引進干擾參數所增加的誤差不超過所選定的干擾值,易言之,由干擾參數法所求出的解幾近最佳解。故干擾參數法在處理相容性問題上,是非常實用、有效的方法。從進一步分析Lagrange 乘數法公式解的過程中,我們也發現了檢驗條件分配"理論"相容的充分條件。
最後,為了驗證 LRG 法與干擾參數法的可行性,我們利用 MATLAB 設計了程式來處理求解過程中的運算,並以 Tian et al.(2009)文中四個可涵蓋各種情況的範例來解釋說明處理的流程,同時將所獲得的結果和 Tian et al. 的結果做比較。 / Given two finite discrete conditional distributions, we could study the compatibility and uniqueness issues. Tian et al.(2009) proposed a unified method by converting the compatibility problem into a system of linear equations with constraints, in which marginal probability values are assumed unknown. It locates the optimum solution by means of the error of l_2 - discrepancy. They also provided criteria for determining the compatibility and uniqueness. Because the condition of sum of the marginal probability values being equal to one is in Tian et al.s’linear system, it might not be fulfilled by the optimum solution. By separating this condition from the linear system and adding into constraints, we would look for the optimum solution after modification.
We propose two new methods: (1) LRG method and (2) Perturbation method. LRG method ignores the requirement of the probability values being between zero and one initially, it then uses the Lagrange multipliers method to derive the solution for a quadratic optimization problem subject to the sum of the marginal probability values being equal to 1. Afterward we use the Rao-Ghangurde method to modify the computed value to meet the requirement.
The perturbation method introduces tiny perturbation parameter in finding the generalized inverse for the optimum solution obtained by the Lagrange multipliers method. It can be shown that the increased error is less than the perturbation value introduced. Thus it is a practical and effective method in dealing with compatibility issues. We also find some sufficient conditions for checking the compatibility of conditional distributions from further analysis on the solution given by Lagrange multipliers method.
To show the feasibilities of LRG method and Perturbation method, we use MATLAB to device a program to conduct them. Several numerical examples raised by Tian et al.(2009) in their article are applied to illustrate our methods. Some comparisons with their method are also presented.
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