The Experts below are selected from a list of 149838 Experts worldwide ranked by ideXlab platform
Arturo Jimenezgutierrez - One of the best experts on this subject based on the ideXlab platform.
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Feasible Design space for shell and tube heat exchangers using the bell delaware method
Industrial & Engineering Chemistry Research, 2007Co-Authors: Medardo Sernagonzalez, Jose Maria Ponceortega, And Agustin J Castromontoya, Arturo JimenezgutierrezAbstract:This paper presents an improved methodology for generating Feasible regions for shell-and-tube exchanger Design, taking into account geometric and operational constraints. The approach is based on the Bell−Delaware method to describe the shell-side flow with no simplification; this approach, therefore, can incorporate the entire range of geometric parameters of practical interest. Compact analytical equations are derived from the rigorous Bell−Delaware method for the shell-side heat transfer coefficient and pressure drop. These equations aid significantly in the solution of the Design problem. The solution involves a nested approach where the compact equation parameters are treated as iteration variables; a simplified heat exchanger model is solved in an inner loop, and the exchanger parameters are updated in an outer loop. Compared to a previous work, which uses the approximate Kern method to describe the shell-side flow, the present one provides a better accuracy for the thermal Design of shell-and-tube...
Arturo Jiménez-gutiérrez - One of the best experts on this subject based on the ideXlab platform.
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Feasible Design Space for Shell-and-Tube Heat Exchangers Using the Bell−Delaware Method
Industrial & Engineering Chemistry Research, 2007Co-Authors: Medardo Serna-gonzález, José María Ponce-ortega, † And Agustín J. Castro-montoya, Arturo Jiménez-gutiérrezAbstract:This paper presents an improved methodology for generating Feasible regions for shell-and-tube exchanger Design, taking into account geometric and operational constraints. The approach is based on the Bell−Delaware method to describe the shell-side flow with no simplification; this approach, therefore, can incorporate the entire range of geometric parameters of practical interest. Compact analytical equations are derived from the rigorous Bell−Delaware method for the shell-side heat transfer coefficient and pressure drop. These equations aid significantly in the solution of the Design problem. The solution involves a nested approach where the compact equation parameters are treated as iteration variables; a simplified heat exchanger model is solved in an inner loop, and the exchanger parameters are updated in an outer loop. Compared to a previous work, which uses the approximate Kern method to describe the shell-side flow, the present one provides a better accuracy for the thermal Design of shell-and-tube...
Salih Demirel - One of the best experts on this subject based on the ideXlab platform.
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Design Optimization of LNAs and Reflectarray Antennas Using the Full-Wave Simulation-Based Artificial Intelligence Models with the Novel Metaheuristic Algorithms
Simulation-Driven Modeling and Optimization, 2016Co-Authors: Filiz Güneş, Salih Demirel, Selahattin NesilAbstract:In this chapter, the two primarily important highly nonlinear Design problems of the contemporary microwave engineering which are “Low Noise Amplifier (LNA)”s and “Reflect-array Antenna (RA)”s are solved as “Design Optimization problems.” For this purpose, firstly the Design problem is defined in terms of the Feasible Design variables (FDVs), the Feasible Design target space (FDTS), both of which are built up by integrating the artificial intelligence black-box models based upon the measurements or full-wave simulations and a suitable metaheuristic search algorithm. In the second stage, Feasible Design target (FDT) or objective function of the optimization procedure is determined as a sub-space of the FDTS. Thirdly, the cost function evaluating the objective is minimized employing a suitable metaheuristic search algorithm with respect to the FDVs. Finally the completed Designs are verified by the professional Microwave Circuitor3-D EM simulators.
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honey bees mating algorithm applied to Feasible Design target space for a wide band front end amplifier
International Conference on Ultra-Wideband, 2012Co-Authors: Peyman Mahouti, Filiz Gunec, Salih DemirelAbstract:In this article, the Feasible Design target space is determined for the input stage-requirements of an ultra-wide band low-noise front end Design using a single transistor. The problem is set as an optimization problem where honey-bees mating have been used as search and optimization tool within in the problem domain. The primary reason to use this algorithm is ease of its use, broad applicability and global perspective. The honey-bee mating process has been considered as a typical swarm-based approach to optimization, in which the search algorithm is inspired by the process of honey-bee mating in real life. In this paper, the honey-bee mating (HBMO) algorithm is presented as a new meta-heuristic optimizationtool to determine Design target space for a microwave amplifier subject to the potential performance of the employed transistor.
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particle swarm intelligence use in Feasible Design target space of a microwave transistor for a wide band output stage requirements
International Conference on Ultra-Wideband, 2012Co-Authors: Salih Demirel, Filiz Gunec, Hamit TorpiAbstract:In this article, the Feasible Design target space is determined for the output stage-requirements of an ultra-wide band low-noise front end Design using a single transistor. For this purpose, a performance characterization of a microwave transistor is achieved to deliver maximum output power subject to the required noise figure F req ≥ F min , using particle swarm intelligence as a comparatively simple and efficient optimization tool. To achieve this, transducer gain of the transistor is maximized as satisfying the physical realization conditions in the case that the input is terminated for the required noise figure F req ≥ F min and the output matched. Thus, the compromise relations between the maximum gain G Tmax and the noise figure F are obtained as the function of the operation frequency and/or input VSWR taking the bias condition (V DS , I DS ) as parameters together with the corresponding source Z S and load Z L terminations for a selected transistor as compared with the analytical counterparts obtained using the microwave, linear circuit and noise theories and an excellent agreement is observed. This type of representation of performance can provide a higher tool to overview all possible Designs in cases where output power or noise figure is at a premium.
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ICUWB - Honey- bees mating algorithm applied to Feasible Design target space for a wide- band front- end amplifier
2012 IEEE International Conference on Ultra-Wideband, 2012Co-Authors: Peyman Mahouti, Filiz Gunec, Salih DemirelAbstract:In this article, the Feasible Design target space is determined for the input stage-requirements of an ultra-wide band low-noise front end Design using a single transistor. The problem is set as an optimization problem where honey-bees mating have been used as search and optimization tool within in the problem domain. The primary reason to use this algorithm is ease of its use, broad applicability and global perspective. The honey-bee mating process has been considered as a typical swarm-based approach to optimization, in which the search algorithm is inspired by the process of honey-bee mating in real life. In this paper, the honey-bee mating (HBMO) algorithm is presented as a new meta-heuristic optimizationtool to determine Design target space for a microwave amplifier subject to the potential performance of the employed transistor.
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ICUWB - Particle swarm intelligence use in Feasible Design target space of a microwave transistor for a wide-band output-stage requirements
2012 IEEE International Conference on Ultra-Wideband, 2012Co-Authors: Salih Demirel, Filiz Gunec, Hamit TorpiAbstract:In this article, the Feasible Design target space is determined for the output stage-requirements of an ultra-wide band low-noise front end Design using a single transistor. For this purpose, a performance characterization of a microwave transistor is achieved to deliver maximum output power subject to the required noise figure F req ≥ F min , using particle swarm intelligence as a comparatively simple and efficient optimization tool. To achieve this, transducer gain of the transistor is maximized as satisfying the physical realization conditions in the case that the input is terminated for the required noise figure F req ≥ F min and the output matched. Thus, the compromise relations between the maximum gain G Tmax and the noise figure F are obtained as the function of the operation frequency and/or input VSWR taking the bias condition (V DS , I DS ) as parameters together with the corresponding source Z S and load Z L terminations for a selected transistor as compared with the analytical counterparts obtained using the microwave, linear circuit and noise theories and an excellent agreement is observed. This type of representation of performance can provide a higher tool to overview all possible Designs in cases where output power or noise figure is at a premium.
Filiz Güneş - One of the best experts on this subject based on the ideXlab platform.
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Design Optimization of LNAs and Reflectarray Antennas Using the Full-Wave Simulation-Based Artificial Intelligence Models with the Novel Metaheuristic Algorithms
Simulation-Driven Modeling and Optimization, 2016Co-Authors: Filiz Güneş, Salih Demirel, Selahattin NesilAbstract:In this chapter, the two primarily important highly nonlinear Design problems of the contemporary microwave engineering which are “Low Noise Amplifier (LNA)”s and “Reflect-array Antenna (RA)”s are solved as “Design Optimization problems.” For this purpose, firstly the Design problem is defined in terms of the Feasible Design variables (FDVs), the Feasible Design target space (FDTS), both of which are built up by integrating the artificial intelligence black-box models based upon the measurements or full-wave simulations and a suitable metaheuristic search algorithm. In the second stage, Feasible Design target (FDT) or objective function of the optimization procedure is determined as a sub-space of the FDTS. Thirdly, the cost function evaluating the objective is minimized employing a suitable metaheuristic search algorithm with respect to the FDVs. Finally the completed Designs are verified by the professional Microwave Circuitor3-D EM simulators.
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particle swarm intelligence applied to determination of the Feasible Design target for a low noise amplifier
Microwave and Optical Technology Letters, 2009Co-Authors: Filiz Güneş, Ufuk Özkaya, Salih DemirelAbstract:analyzer over 0 –1 GHz frequency range is shown in Figure 3. The system automatically set the carrier frequency at the maximum of pass-band response, i.e., around 610 MHz and started normal operation. Perfectly open eye pattern was observed on the oscilloscope. To investigate nonlinear distortions we quadrupled the transmitters. Then four 10 Mbit/s BFSK signals were sent simultaneously over the tested fiber. Their subcarriers frequencies had 40 MHz spacing and were set at 530, 570, 610, and 650 MHz. The frequency modulation index was around unity in each channel, which ensured that the channel bandwidth following from the Carson rule [7] was less than the channel spacing, i.e., no channel overlapping took place. The receiver was tuned in turn to each channel and the resulting eye patterns were recorded. They are shown in Figure 4. They correspond to the 2 11 -1 pseudorandom sequence. Again, they all exhibit the perfect opening and the nonlinear distortions had no visible influence despite the fact that the laser was not optimized for analog operation. 4. CONCLUSIONS We have demonstrated a SCM system successfully operating in the pass-band of 1 km MM GI optical fiber. Such a system may be easily added to existing base-band systems such as Fast Ethernet. The system automatically adjusts the carrier frequency to the fiber frequency response. CNR is obviously a better estimate for the channel selection but the two are equivalent if the receiver noise is white, which holds true in most cases. We have also shown a transmission of four 10 Mbit/s BFSK channels over the same fiber. No visible channel interaction was observed. This is due to the BFSK immunity to nonlinear interference as well as to the fact that the channel frequencies occupied less than octave so the second order distortions fell outside the useful frequency range. ACKNOWLEDGMENT
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Particle swarm intelligence applied to determination of the Feasible Design target for a low‐noise amplifier
Microwave and Optical Technology Letters, 2009Co-Authors: Filiz Güneş, Ufuk Özkaya, Salih DemirelAbstract:analyzer over 0 –1 GHz frequency range is shown in Figure 3. The system automatically set the carrier frequency at the maximum of pass-band response, i.e., around 610 MHz and started normal operation. Perfectly open eye pattern was observed on the oscilloscope. To investigate nonlinear distortions we quadrupled the transmitters. Then four 10 Mbit/s BFSK signals were sent simultaneously over the tested fiber. Their subcarriers frequencies had 40 MHz spacing and were set at 530, 570, 610, and 650 MHz. The frequency modulation index was around unity in each channel, which ensured that the channel bandwidth following from the Carson rule [7] was less than the channel spacing, i.e., no channel overlapping took place. The receiver was tuned in turn to each channel and the resulting eye patterns were recorded. They are shown in Figure 4. They correspond to the 2 11 -1 pseudorandom sequence. Again, they all exhibit the perfect opening and the nonlinear distortions had no visible influence despite the fact that the laser was not optimized for analog operation. 4. CONCLUSIONS We have demonstrated a SCM system successfully operating in the pass-band of 1 km MM GI optical fiber. Such a system may be easily added to existing base-band systems such as Fast Ethernet. The system automatically adjusts the carrier frequency to the fiber frequency response. CNR is obviously a better estimate for the channel selection but the two are equivalent if the receiver noise is white, which holds true in most cases. We have also shown a transmission of four 10 Mbit/s BFSK channels over the same fiber. No visible channel interaction was observed. This is due to the BFSK immunity to nonlinear interference as well as to the fact that the channel frequencies occupied less than octave so the second order distortions fell outside the useful frequency range. ACKNOWLEDGMENT
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Design of a broadband microwave amplifier using neural performance data sheets and very fast simulated reannealing
International Symposium on Neural Networks, 2006Co-Authors: Yavuz Cengiz, Hüseyin Göksu, Filiz GüneşAbstract:In this work, the neural performance data sheets of the transistor are employed to determine the Feasible Design target space in the optimization of a microwave amplifier. The basic amplifier with a single transistor between the input and output matching circuits (IMC and OMC) is also worked out. Very Fast Simulated Reannealing (VFSR) is utilized in the multi – objective optimization process for the global minimum of the objective function which is expressed as a function only gain of a matching circuit, in the negative exponential form to ensure the rapid convergence.
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ISNN (2) - Design of a broadband microwave amplifier using neural performance data sheets and very fast simulated reannealing
Advances in Neural Networks - ISNN 2006, 2006Co-Authors: Yavuz Cengiz, Hüseyin Göksu, Filiz GüneşAbstract:In this work, the neural performance data sheets of the transistor are employed to determine the Feasible Design target space in the optimization of a microwave amplifier. The basic amplifier with a single transistor between the input and output matching circuits (IMC and OMC) is also worked out. Very Fast Simulated Reannealing (VFSR) is utilized in the multi – objective optimization process for the global minimum of the objective function which is expressed as a function only gain of a matching circuit, in the negative exponential form to ensure the rapid convergence.
Chunhung Chen - One of the best experts on this subject based on the ideXlab platform.
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minimizing opportunity cost in selecting the best Feasible Design
Winter Simulation Conference, 2013Co-Authors: Nugroho A Pujowidianto, Loo Hay Lee, Chunhung ChenAbstract:Constrained ranking and selection (R&S) refers to the problem of selecting the best Feasible Design where both main objective and constraint measures need to be estimated via stochastic simulation. Despite the growing interests in constrained R&S, none has considered other selection qualities than a statistical measure called the probability of correct selection (PCS). In contrast, several new developments in other R&S literatures have considered financial significance as the selection quality. This paper aims to lay the foundation of using other selection qualities by attempting to minimize the opportunity cost in allocating the limited simulation budget. The opportunity cost is defined and two allocation rules which minimize its upper bound are presented together with a fully-sequential heuristic algorithm for implementation.
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Winter Simulation Conference - Minimizing opportunity cost in selecting the best Feasible Design
2013 Winter Simulations Conference (WSC), 2013Co-Authors: Nugroho A Pujowidianto, Loo Hay Lee, Chunhung ChenAbstract:Constrained ranking and selection (R&S) refers to the problem of selecting the best Feasible Design where both main objective and constraint measures need to be estimated via stochastic simulation. Despite the growing interests in constrained R&S, none has considered other selection qualities than a statistical measure called the probability of correct selection (PCS). In contrast, several new developments in other R&S literatures have considered financial significance as the selection quality. This paper aims to lay the foundation of using other selection qualities by attempting to minimize the opportunity cost in allocating the limited simulation budget. The opportunity cost is defined and two allocation rules which minimize its upper bound are presented together with a fully-sequential heuristic algorithm for implementation.
