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combined algorithm to compute D-optimal designs

JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS 2015年 278卷 248-257页

作者： Martin Martin, Raul Camacha Gutierrez, Irene Garcia Univ Castilla La Mancha Dept Math Toledo Spain

algorithmic techniques for computing optimal designs continue being a need in the optimal experimental design field. The increasing interest in finding the optimal experimental conditions makes that new methods are demanded for more complex frameworks showing more realistic situations. Numerical techniques are often the unique viable option for computing these designs since to tackle analytically the problem results impracticable in most of cases. Wynn-Fedorov algorithm, multiplicative algorithm and their modifications are the more frequently used methods in the literature for computing D-optimal designs. However, they are not always suitable and efficient to compute optimal designs since their procedures are very limited by the computational requirements. A new algorithm to obtain D-optimal designs is proposed in this paper. It is based on combining suitable strategies followed by the traditional algorithms. A proof of the convergence is provided and several numerical examples are presented to illustrate its improved results. (C) 2014 Elsevier B.V. All rights reserved.

关键词： D-optimum design Multiplicative algorithm Wynn-Fedorov algorithm combined algorithm

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combined Dust Detection algorithm for Asian Dust Events Over East Asia Using GK2A/AMI: a Case Study in October 2019

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ASIA-PACIFIC JOURNAL OF ATMOSPHERIC SCIENCES 2022年第1期58卷 45-64页

作者： Jang, Jae-Cheol Lee, Soobong Sohn, Eun-Ha Noh, Yoo-Jeong Miller, Steven D. Korea Meteorol Adm Natl Meteorol Satellite Ctr 64-18 Guam Gil Jincheon Gun 27803 Chungcheongbuk South Korea Colorado State Univ Cooperat Inst Res Atmosphere CIRA Ft Collins CO 80523 USA

A combined algorithm comprising multiple dust detection methods was developed using infrared (IR) channels onboard the GEOstationary Korea Multi-Purpose SATellite 2A equipped with the Advanced Meteorological Imager (GK2A/AMI). Six cloud tests using brightness temperature difference (BTD) were utilized to reduce errors caused by clouds. For detecting dust storms, three standard BTD tests (i.e., BT12.3 - BT10.5, BT8.7 - B-10.5, and BT11.2 - BT10.5) were combined with the polarized optical depth index (PODI). The combined algorithm normalizes the indices for cloud and dust detection, and adopts weighted combinations of dust tests depending on the observation time (day/night) and surface type (land/sea). The dust detection results were produced as quantitative confidence factors and displayed as false color imagery, applying a dynamic enhancement background reduction algorithm (DEBRA). The combined dust detection algorithm was qualitatively assessed by comparing it with dust RGB imageries and ground-based lidar data. The combined algorithm especially improved the discontinuity in weak dust advection to the sea and considerably reduced false alarms as compared to previous dust monitoring methods. For quantitative validation, we used aerosol optical thickness (AOT) and fine mode fraction (FMF) derived from low Earth orbit (LEO) satellites in daytime. For both severe and weakened dust cases, the probability of detection (POD) ranged from 0.667 to 0.850 and it indicated that the combined algorithm detects more potential dust pixels than other satellites. In particular, the combined algorithm was advantageous in detecting weak dust storms passing over the warm and humid Yellow Sea with low dust height and small AOT.

关键词： GK2A/AMI Asian dust Dust detection combined algorithm

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Capacitor banks selection in radial distribution networks by combined algorithm

Technical Electrodynamics

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Technical Electrodynamics 2015年第6期2015卷 58-62页

作者： Zubiuk, Y. Trach, I. Sevasjuk, I. Institute of Electrodynamics of the National Academy of Sciences of Ukraine pr. Peremohy 56 Kyiv-57 03680 Ukraine

This paper presents the combined algorithm for determination of locations and sizes of capacitor banks in the radial distribution networks for practical minimization of power losses and costs of these losses and banks. The method of concessions and modified PSO-method are applied in the proposed algorithm. Additionally the technicalcoenosis criterion is applied for the specific account of technical and economic factors. The proposed approach allows to obtain the efficient practical solutions and increased stabilization of voltage profile in the radial distribution network. References 9, figures 2, tables 4.

关键词： Capacitor bank combined algorithm Method of concessions PSO-method Radial distribution network Technicalcoenosis criterion

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3D Adaptive combined DE/FE algorithm for Analyzing Impact Fracture of Laminated Glass

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INTERNATIONAL JOURNAL OF COMPUTATIONAL METHODS 2019年第4期16卷

作者： Xu, Wei Zang, Mengyan Sakamoto, Jiro Zhang, Shupei Jiangsu Univ Sch Automot & Traff Engn Zhenjiang 212013 Jiangsu Peoples R China Kanazawa Univ Coll Sci & Engn Sch Mech Engn Kanazawa Ishikawa 9201192 Japan South China Univ Technol Sch Mech & Automot Engn Guangzhou 510641 Guangdong Peoples R China

Laminated glass has been wildly employed in automobile windshields, modern buildings, etc. thanks to its security and durability performance. A novel 3D adaptive combined DE/FE algorithm is proposed to research its impact fracture mechanical properties if the fracture region is small relative to a specimen while the cracks are propagating at a random position. The proposed method can automatically convert the distorted finite elements into the spherical discrete elements during simulating the impact fracture of laminated glass. In this method a system is completely discretized into the finite elements at the initial moment without any discrete element existing until part of the finite elements becoming severely deformed. Subsequently each finite element, whose maximum tensile stress exceeds a user-specified conversion criterion, is converted into eight spherical discrete elements. At the same time the system is fragmented into two subdomains, the finite element (FE) and the discrete element (DE) subdomains. An extrinsic cohesive fracture model is adaptively adopted only in the DE subregion to capture the crack propagation when the normal stress between the DEs equals or exceeds the cohesive strength. The impact fracture of a glass beam is simulated by the adaptive algorithm and the discrete element method, respectively. Beside of the micro-cracks and cohesive zone, almost the same crack patterns are captured by both the numerical methods. Fortunately, the efficiency of the proposed method is much higher (10 times in this case) than that of the pure DEM. A satisfactory agreement of the simulation results certified the feasibility and effectiveness of such an adaptive algorithm. Finally, the impact fracture simulation is performed by the adaptive algorithm on a laminated glass beam which has the same size as the experimental specimens. Besides of the differences on the cracks occurrence and propagation angle, a similar agreement of the fracture patterns is observed as

关键词： combined algorithm discrete element method laminated glass cohesive model brittle fracture

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Study on an improved burnup algorithm in Kylin-2 code

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ANNALS OF NUCLEAR ENERGY 2021年 153卷 108034-108034页

作者： Hu, Yuying Liao, Hongkuan Luo, Qi Yao, Dong Yu, Yingrui Zhou, Bingyan Nucl Power Inst China Sci & Technol Reactor Syst Design Technol Lab Chengdu Peoples R China China Inst Atom Energy Beijing Peoples R China

Kylin-2 is an advanced neutronics lattice code, developed by Nuclear Power Institute of China. Chebyshev Rational Approximation Method (CRAM) is used in Kylin-2 to solve the burnup chains. This method has the characters of high calculation accuracy and good computational stability, which is the most widely used numerical solution nowadays. However, when solving the large-scale matrices, the computing time would sharply increase, so the burnup calculation efficiency of Kylin-2 is not very high. In this study, an improved CRAM based on order reduction with Krylov Subspace Method (KSM), combined algorithm, has been used to solve burnup equations. According to the verification and analysis, comparing to CRAM, Kylin-2 code with combined algorithm has higher efficiency in burnup calculation while maintaining the accuracy. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： Burnup calculation combined algorithm Improved CRAM Kylin-2 code

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Recovering of Corrupted Ultrasonic Waves, for Determination of TOF Using the Zero-Crossing Detection Technique

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IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT 2019年第11期68卷 4234-4241页

作者： Fabiano dos Santos, Jean Carlos Pinheiro, Priscila Pagliari de Franca, Jose Alexandre Univ Estadual Londrina Dept Elect Engn BR-86057970 Londrina Brazil

Time-of-flight (TOF) measures are valuable in the estimation of displacements, distances, and moving fluids' speed, e.g., the wind. Of the different types of methods that measure wind speed, the ultrasound is highlighted. As part of the calculation required to acquire the wind speed, one must find the time that an ultrasonic wave takes to travel from one particular place to another. This time is known as TOF. The biggest challenge in measuring TOF is to determine the correct moment when the ultrasonic wave arrived at the reception because it will be immersed in noise and its envelope probably will be corrupted by the actions of the wind. The methodology proposed by this paper presents a combined algorithm between an extended Kalman Filter (EKF) and a zero-crossing detector (ZCD) technique. The EKF method is responsible for the noise elimination stage and estimation of the real ultrasound's envelope, while the ZCD detects the correct TOF of the estimated signal. This paper also presents the flaws and solutions found for each technique. It was shown that for speeds up to 75 km/h, the coefficient that was found to be R-2 = 0.99977.

关键词： combined algorithm envelope fluid flow measurement Kalman filter ultrasonic transducers

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Fatigue life assessment of FRP cable for long-span cable-stayed bridge

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COMPOSITE STRUCTURES 2019年 210卷 159-166页

作者： Feng, Bo Wang, Xin Wu, Zhishen Southeast Univ Minist Educ Key Lab C&PC Struct Nanjing 210096 Jiangsu Peoples R China Southeast Univ Int Inst Urban Syst Engn Nanjing 210096 Jiangsu Peoples R China Southeast Univ Natl & Local Unified Engn Res Ctr Basalt Fiber Pr Nanjing 210096 Jiangsu Peoples R China

This study evaluates fatigue life of carbon fiber reinforced polymer (CFRP), basalt fiber reinforced polymer (BFRP) and steel cables considering the sag effect for cable-stayed bridges with various safety factors. The fatigue cycles of the cables during designed service period were first studied by an analysis of vehicle load statistics. The least favorable cables and their stress amplitudes were determined by finite element (FE) analysis. Fatigue life assessment based on the design stress and service life of the cable was conducted by developing the combined algorithm of equivalent transformation. The results indicate that the cables in the bridge undergo approximately up to 1.14 x 10(9) fatigue cycles during 100 service years. The most unfavorable cable is the one in the mid-span position, and its equivalent stress amplitude is almost 12 times the actual stress amplitude. The fatigue life of CFRP cables increases much faster than that of BFRP and steel cables with increasing of safety factor. The fatigue lives of CFRP and BFRP cables are 3 and 1A times, respectively, compared to that of a steel cable with the safety factor of 2.55. To satisfy 100 years of design life, safety factor of CFRP, BFRP and steel cables should be no less than 2.55, 3.27 and 3.64, respectively.

关键词： Cable-stayed bridge Long-span FRP cable combined algorithm Fatigue life assessment

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Optimal Cordon-Based Congestion Pricing Considering Feasible Cordons and Congestion Transfer

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IEEE ACCESS 2019年 7卷 93545-93557页

作者： Luo, Qing-Yu Zhu, Jia-Xiang Guan, Xin-Yu Jia, Hong-Fei Jilin Univ Transportat Coll Dept Transportat Planning & Management Changchun 130022 Jilin Peoples R China Shenzhen Urban Transport Planning Ctr Shenzhen 518057 Peoples R China

As one of the most effective traffic demand management measures, cordon-based congestion pricing can alleviate recurrent traffic congestion. Existing methods of determining the toll cordon require an excessive investigation and calculation, and the model assumptions are too idealistic. This article attempts to reduce the amount of required calculation by introducing feasible cordons. Through GPS data of floating cars, an accurate identification of the research scope and a feasible cordon for congestion pricing can be achieved. Further, considering multi-user choices and congestion transfer when pricing is imposed, this article establishes a joint bi-level model to determine the toll cordons and rate simultaneously. The upper level of the model aims at maximizing social welfare with the restriction of congestion transfer. The lower level of the model is a road network equilibrium model in which the value of time is considered. A combined algorithm is adopted to solve the bi-level model. Finally, the effectiveness of the method is verified by taking Changchun as an example. This article provides a methodological support for designing a feasible and an effective cordon-based congestion pricing scheme.

关键词： Congestion pricing bi-level programming model feasible cordon combined algorithm GPS data

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Electromagnetic Scattering from Random Rough Surfaces with Multiple Elevations for GNSS-R Land Applications

Electromagnetic Scattering from Random Rough Surfaces with M...

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USNC-URSI Radio Science Meeting / IEEE International Symposium on Antennas and Propagation (AP-S)

作者： Zhu, Jiyue Tsang, Leung Univ Michigan Dept Elect Engn & Comp Sci Ann Arbor MI 48109 USA

ISBN: (纸本)9781728106922

The Global Navigation Satellite System Reflectometry (GNSS-R) for remote sensing has attracted lots of attentions. In this paper, a scattering model by combining numerical Kirchhoff simulator (KA) and numerical solutions of Maxwell equations in 3D (NMM3D) is developed for GNSS-R land applications. The significant difference with past scattering models is that microwave rough surfaces (cm scale) are superimposed on multiple elevations (meter scale) of land. The elevation information are provided by DEM (digital elevation models) data. In the model, exact coherent and incoherent field of rough surface on each elevation (DEM patch) is obtained from NMM3D. With NMM3D outputs, KA simulator is used to calculate phase variations caused by elevations and then get total power received. The combined algorithm considers both coherent and incoherent contributions. It is applicable for simulations of land surface with dozens of kilometers, which is important for analysis of GNSS-R signals. Results of combined algorithm are many dB different with existing coherent and incoherent model, and also larger than KA simulator.

关键词： rough surfaces on multiple elevations GNSS-R combined algorithm Kirchhoff simulator NMM3D DEM

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Task scheduling for multi-electro-magnetic detection satellite with a combined algorithm

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Journal of Systems Engineering and Electronics 2012年第1期23卷 88-98页

作者： Jianghan Zhu Lining Zhang Dishan Qiu Haoping Li Science and Technology on Information Systems Engineering Laboratory National University of Defense Technology Changsha 410073 P. R. China Northern Electronic Equipment Institute Beijing 100191 P. R. China

Task scheduling for electro-magnetic detection satellite is a typical combinatorial optimization problem. The count of constraints that need to be taken into account is of large scale. An algorithm combined integer programming with constraint programming is presented. This algorithm is deployed in this problem through two steps. The first step is to decompose the original problem into master and sub-problem using the logic-based Benders decomposition; then a circus combines master and sub-problem solving process together, and the connection between them is general Benders cut. This hybrid algorithm is tested by a set of derived experiments. The result is compared with corresponding outcomes generated by the strength Pareto evolutionary algorithm and the pure constraint programming solver GECODE, which is an open source software. These tests and comparisons yield promising effect.

关键词： task scheduling combined algorithm logic-based Benders decomposition combinatorial optimization constraint programming （CP）.

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