We formulate the problem of designing gradient-index optical coatings as the task of solving a system of operator equations. We use iterative numerical procedures known from the theory of inverse problems to solve it ...
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We formulate the problem of designing gradient-index optical coatings as the task of solving a system of operator equations. We use iterative numerical procedures known from the theory of inverse problems to solve it with respect to the coating refractive index profile and thickness. The mathematical derivations necessary for the application of the procedures are presented, and different numerical methods (Landweber, Newton, and Gauss-Newton methods, Tikhonov minimization with surrogate functionals) are implemented. Procedures for the transformation of the gradient coating designs into quasi-gradient ones (i.e., multilayer stacks of homogeneous layers with different refractive indices) are also developed. The design algorithms work with physically available coating materials that could be produced with the modern coating technologies. (C) 2012 Optical Society of America
High-power light-emitting diodes can dissipate several times more heat power than conventional lighting devices, while keeping the junction temperature below a security value, in order to assure reliability and low li...
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High-power light-emitting diodes can dissipate several times more heat power than conventional lighting devices, while keeping the junction temperature below a security value, in order to assure reliability and low light decay. No fans are usually permitted, so the heat dissipation solution should adopt new technological advances that are required in the form of lighter, shape-embedded heat-sink devices. The present study addresses the implementation of a special heat-dissipation technology, known as a loop heat pipe, consisting of an evaporator, a condenser, a compensation chamber, and vapor and liquid lines for cooling particular types of devices, such as light-emitting diodes, through the phase-change cooling method. In this paper a new algorithm to simulate this loop heat pipe is presented. This mathematical model is based on steady-state energy balance equations for each main component. Finally, a validation procedure through a fully monitored experimental test is performed to show the effects of different key parameters on the heat load such as radius and length of the vapor line, wick thickness and condensing temperature. It produces an effective optimization of the original design, representing an innovative tool for design assessment, to determine the influence of these key performance parameters for each particular application. Finally, a case study is presented for the optimization of a loop heat pipe design, applied to the cooling of an 80 W street lamp. (C) 2016 Elsevier Ltd. All rights reserved.
This paper presents a new method of designing scalar functional observers of order less than the well-known upper bound ( v-1). A condition for the existence of observers of order p where 1 <= p <= (v-1) is give...
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This paper presents a new method of designing scalar functional observers of order less than the well-known upper bound ( v-1). A condition for the existence of observers of order p where 1 <= p <= (v-1) is given. A simple and effective algorithm for solving the constrained generalized Sylvester equation is proposed. Several numerical examples are given to illustrate the attractiveness of the design algorithm.
The paper reports an analytical study on the design overstrength of steel eccentrically braced frames (EBFs). The study aimed at examining the influence of geometrical factors and seismic hazard on the design overstre...
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The paper reports an analytical study on the design overstrength of steel eccentrically braced frames (EBFs). The study aimed at examining the influence of geometrical factors and seismic hazard on the design overstrength of EBFs. Pursuant to this goal a computer program which facilitates EBF designs was developed. The algorithm of the program adopts the lightest uniform frame design and library of link-beam-brace sub-assemblages concepts. The design output from the program was compared with published solutions and the results indicate that the algorithm developed as a part of this study is capable of providing lighter framing solutions. A parametric study was conducted using the developed computer program. The results indicate that the frames considered in this study have on average higher overstrength values when compared with the codified value even without considering potential increases due to material overstrength and strain hardening. The design overstrength was found to be influenced primarily by the link length to bay width ratio and the bay width, and secondarily by the building height and seismic hazard level.
Technological innovations play a crucial role in designing an effective green supply chain. However, it is crucial to know the factors influencing technological innovation in a green supply chain. Some preconceptions ...
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Technological innovations play a crucial role in designing an effective green supply chain. However, it is crucial to know the factors influencing technological innovation in a green supply chain. Some preconceptions show that technological innovation in a business can be affected by internal and external factors, and therefore there must be correlations between such factors to flourish the technological innovation and, subsequently, the green supply chain. Besides, predicting the technological innovation level in a supply chain can be vital and direct it to the Industry 5.0 goals. In this research, a 3-phased framework will be proposed to predict the Technological Innovation Level of Green Supply Chains. The scope of this research includes Green Investment, Eco-friendly design and Customer Collaborations. In the 1st phase of the framework, dependent and independent factors considering the scope of the Research will be determined;and then, using statistical data analysis, the weight of factors, which reflects their impact on technological innovation (dependent factor), will be determined. Then, in the 2nd phase, a comprehensive model will be developed and trained. Using the data of supply chains that were gathered in the first phase, the train and test data would be selected. In continuation, the model will be trained and its performance will be evaluated using some metrics. Then, in the last phase (phase 3), the developed model will be used to predict the technological level of supply chains. The outcomes of this research can help top managers of supply chains to predict the level of technological innovation by investing a certain budget in improving the dependent variables. The outcomes demonstrated that Customer Collaboration (0.481), Eco-friendly design (0.419) and Green Investment (0.41) have significant impacts on technological innovation improvement in the studied cases, respectively. Besides, the results showed the superiority of the K-nearest Neighbor algor
A nonlinear observer is considered for a class of continuous nonlinear descriptor systems subject to unknown inputs and faults. This class is partly characterized by globally Lipschitz nonlinearities, and a member sys...
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A nonlinear observer is considered for a class of continuous nonlinear descriptor systems subject to unknown inputs and faults. This class is partly characterized by globally Lipschitz nonlinearities, and a member system may be singular and possibly non-causal. The observer structure chosen makes it useful for both state estimation for feedback controls and residual generation for fault detection. Results on the existence of solutions are given and some useful bounds are derived which are important in the observer design, which is based on a transformed system and on the solution of a Riccati equation. The existence, convergence properties and robustness of the observer are investigated by the use of a quadratic Lyapunov function. Conditions are given for a bound to hold on the norm of the transfer function relating the residual error to the disturbance (linear case). A design algorithm is given and applied to the estimation of the states of a flexible joint robot.
More and more unconventional timing silent chain systems are used in the low-emission vehicles or hybrid vehicles, but engineering practices show that the classical design method cannot ensure the stability and the fe...
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More and more unconventional timing silent chain systems are used in the low-emission vehicles or hybrid vehicles, but engineering practices show that the classical design method cannot ensure the stability and the feasibility anymore. According to the angular velocity fluctuations of crankshaft, the maximum accumulation length is calculated to design the ideal path of the tension side chain. The tension rate is defined to determine the ideal chain path at the loose side. In order to match the ideal chain paths with the actual chain length, the pitch variation algorithm is proposed. Based on a specific inline engine, the unconventional timing silent chain system is designed by the classical design method and the new design method respectively. The design process proves that the new method is belonging to a real parametric design, and it can expediently and quickly obtain the results. With the dynamics simulation comparison, the results show that the operation performance of the unconventional timing system can be roundly and significantly improved by using the new design method. Furtherly, this new design method is not only suitable for the unconventional timing system, but also suitable for the other types of timing systems.
Most of the conventional design methods of large-scale domes need deep engineering insight;furthermore, they hardly give the most economical solutions. Therefore, in this paper, a new practical design algorithm is pre...
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Most of the conventional design methods of large-scale domes need deep engineering insight;furthermore, they hardly give the most economical solutions. Therefore, in this paper, a new practical design algorithm is presented to automate optimal geometry and sizing design of the latticed space domes through the idea of using parametric mathematical functions. Moreover, a simple approach is developed for the optimal sizing design of trusses with outsized number of elements. The robust technique of particle swarm optimization is employed to find the solution of the propounded optimization problem. Some numerical examples on the minimum weight design of several famous domes are provided to demonstrate the efficiency of the proposed design algorithm.
A generative design system subdivides a real physical space a user actually lives in and recreates it through object-oriented programming, and depending on the situation of the design process, variable data are arrang...
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A generative design system subdivides a real physical space a user actually lives in and recreates it through object-oriented programming, and depending on the situation of the design process, variable data are arranged in a hierarchy to set up parameters so that an efficient shape can be drawn. A pleasant environment of the user space is considered under various space-related conditions during the design process using data obtained from an environment analysis simulation based on the building code. This study focuses on the methodology of processing and utilizing variable data derived by the parameterization of the analysis data through a simulation using sensor measurement equipment to analyze user behavioral design patterns and obtain the intensity of illumination of the interior space, which is the spatial variable data element that forms the actual physical space. After systematizing the variable values through motion capture, during the process of designing, as a sketch, a design algorithm will be formed, which will be utilized as the generative design algorithm. Further, a method for improving the design quality using a computer-based design algorithm will be investigated, and whether the design method can be improved further will be predicted. Relevance to design Practice - This study utilizes various sensor-based IT technologies and environmental analysis data to design an optimal solution fit for a user environment and investigates whether a methodology could be applied to the design process to help improve the design through a generative design system by the processing of variable data.
It is shown that the problem of observer design for estimating a set of linear combinations of state variables of a plant can be formulated in terms of linear matrix inequalities. An algorithm for constructing functio...
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It is shown that the problem of observer design for estimating a set of linear combinations of state variables of a plant can be formulated in terms of linear matrix inequalities. An algorithm for constructing functional observers is proposed based on a nonsingular transformation of a plant model in the state space by matrix canonization with subsequent solution of the system of linear matrix inequalities.
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