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Strongly Proper Efficient Solutions: Efficient Solutions with Bounded Trade-Offs

JOURNAL OF optimization THEORY AND APPLICATIONS 2016年第3期168卷 864-883页

作者： Khaledian, Kazhal Khorram, Esmaile Soleimani-damaneh, Majid Amirkabir Univ Technol Fac Math & Comp Sci 424 Hafez Ave Tehran 15914 Iran Univ Tehran Sch Math Stat & Comp Sci Coll Sci Tehran Iran Inst Res Fundamental Sci IPM Sch Math POB 19395-5746 Tehran Iran

In multiple-objective optimization literature, a properly efficient solution has been interpreted as a point in which the trade-offs between all objectives are bounded. In this paper, it is shown that this boundedness does not necessarily hold for problems with three or more objective functions. It is possible that in a properly efficient solution the trade-offs between some objectives are unbounded. To overcome this, in this paper strongly proper efficient solutions are introduced, in which the trade-offs between all objectives are bounded. This notion is defined in different senses, and the relationships between them are investigated. In addition to theoretical discussions, some clarifying examples are given.

关键词： multiple-objective optimization Proper efficiency Strong proper efficiency Trade-off

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Classifying the minimum-variance surface of multiple-objective portfolio selection for capital asset pricing models

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ANNALS OF OPERATIONS RESEARCH 2022年第2期311卷 1203-1227页

作者： Qi, Yue China Acad Corp Governance 94 Weijin Rd Tianjin 300071 Peoples R China Nankai Univ Business Sch Dept Financial Management 94 Weijin Rd Tianjin 300071 Peoples R China

Portfolio selection is recognized as the birth-place of modern finance;Markowitz emphasizes computing whole efficient frontiers. Moreover, computing efficient sets has long been a topic in multiple-objective optimization. After portfolio selection, an important research direction is capital asset pricing models (CAPM). Black and Fama prove the existence of a unique zero-covariance portfolio on the minimum-variance frontier. By the zero-covariance relationship, Roll then classifies the minimum-variance frontier into a positive-covariance side and a negative-covariance side;Fama and Roll further prove zero-covariance CAPM. Recently, researchers gradually realize additional criteria and extend portfolio selection into multiple-objective portfolio selection. Consequently, the minimum-variance frontier extends to a minimum-variance surface. Moreover, the extension naturally raises questions of classifying the surface for multiple-objective CAPM. There has been no such research until now. In such an area, this paper contributes to the literature by extending the classification. We classify the surface into a positive-covariance side and a negative-covariance side, although the classification depends on specific portfolios and is thus non-uniform. We then analyze classification properties and extend relevant theorems by proposing conjectures, although the conjectures are disproved by theorems and counter-examples. Moreover, we forward the research methodology to general k-objective models, so research arenas for multiple-objective CAPM are opened. This paper brings researchers one step closer to classifying the minimum-variance surface and extending CAPM.

关键词： multiple-objective optimization multiple-objective portfolio selection Minimum-variance surface Paraboloid Classification Zero-covariance portfolio Capital asset pricing models (CAPM) multiple-objective CAPM

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NONCONICAL OPTIMALITY CONDITIONS - SOME ADDITIONAL RESULTS

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JOURNAL OF optimization THEORY AND APPLICATIONS 1983年第4期41卷 619-623页

作者： HAZEN, GB MORIN, TL PURDUE UNIV SCH IND ENGNW LAFAYETTEIN 47907

The purpose of the present note is to provide a somewhat more flexible statement of the sufficiency conditions in Section 4 of Ref. 1 and to give explicit statements of the fundamental necessity and sufficiency results, which were only implicitly presented there. The additional flexibility is obtained by considering local, rather than global, pseudoconcavity requirements.

关键词： multiple-objective optimization vector optimization existence theorems first-order optimality conditions normed linear spaces

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Development of a hybrid CFD-ANN method with multi-objective optimization for airfoil-finned PCHE used in Gen-IV nuclear systems

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PROGRESS IN NUCLEAR ENERGY 2024年 175卷

作者： Ding, Jinneng Liu, Qihang Ke, Juntao Deng, Mingjie Yu, Guopeng Liang, Youcai South China Univ Technol Sch Elect Power Engn Guangzhou 510640 Peoples R China Shanghai Engn Res Ctr Space Engine Shanghai Inst Space Prop Shanghai 201112 Peoples R China Sun Yat Sen Univ Sino French Inst Nucl Engn & Technol Guangzhou 519082 Guangdong Peoples R China

The airfoil printed circuit heat exchanger (PCHE) is among the most promising exchangers for the supercritical carbon dioxide Brayton cycles in Gen-IV nuclear systems due to its high efficiency and compactness. To optimize the design and analysis of the novel structure, this paper proposes a hybrid CFD-ANN method for the airfoil PCHE with multiple-objective optimization. Firstly, it explores the impact of structural parameters on thermo-hydraulic performance and the synergistic effect of different parameters. It was found that thickness significantly impacts heat exchange and pressure drop, which diminishes when both vertical and horizontal spacing are larger. Smaller horizontal spacing can increase the compactness of the heat exchanger while causing minimal changes in the heat transfer coefficient and pressure drop. Compared to the CFD method, the ANN method can significantly reduce the simulation time from 2 h to 1 s, with a mean absolute percentage error of only 0.61%. In addition, using ANN as the fitness function, and taking the heat transfer coefficient, pressure drop, and compactness as optimization objectives, the results of the optimized design were obtained based on the NSGA-II algorithm. Compared to the original design, the friction factor of optimal design is decreased by 10%, and the compactness increased by 14.8%.

关键词： Airfoil PCHE Hybrid CFD-ANN method multiple-objective optimization Heat transfer and flow correlations

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Simulation-based optimal calibration of spark ignition engines with multiple objectives: fuel economy and combustion variability

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PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART D-JOURNAL OF AUTOMOBILE ENGINEERING 2011年第D10期225卷 1427-1442页

作者： Lee, T-K Kramer, D. Ohl, G. Filipi, Z. S. Univ Michigan Dept Mech Engn Ann Arbor MI 48109 USA USA RDECOM TARDEC Warren MI USA Adapt Mat Inc Ann Arbor MI USA

Optimal engine calibration methodology at part-load operating conditions using a multi-scale simulation approach is proposed and demonstrated on a spark ignition engine with dual-independent variable valve timing and a charge motion control valve. Fuel economy is typically selected as a calibration objective at part-load operating conditions. However, to secure vehicle driveability and smooth engine operation with low vibration and harshness, the combustion variability is considered by introducing the coefficient of variation in the indicated mean effective pressure characterized through a statistical analysis of experimental data. Other engine responses are fully predicted through a co-simulation approach by implementing the quasi-dimensional combustion simulation into the one-dimensional gas exchange simulation, and subsequently captured by an artificial neural network for fast computation. The best actuator set points are determined by solving the constrained multiple-objective optimization problem with fuel economy and combustion variability objectives under part-load conditions. The calibration eliminates a high combustion variability at low loads and low speeds, maintaining most of the fuel economy benefit achievable with variable valve timing, and it can be used for an implementable feedforward control strategy.

关键词： internal combustion engine optimal calibration combustion variability fuel economy multiple-objective optimization artificial neural network virtual sensing

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Multi-objective Topology optimization for Curved Arm of Multifunctional Billet Tong Based on Characterization of Working Conditions

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JOURNAL OF ENGINEERING AND TECHNOLOGICAL SCIENCES 2022年第1期54卷 199-222页

作者： Liu, Jialiang Wang, Zhaohua Song, Dezhuang Wu, Fenghe Yanshan Univ Sch Mech Engn Qinhuangdao 066004 Hebei Peoples R China Shanghai Dianji Univ Mech Inst Shanghai 201306 Peoples R China Shanghai Large Scale Casting & Forging Mfg Techno Shanghai 201306 Peoples R China Heavy Duty Intelligent Mfg Equipment Innovat Ctr Qinhuangdao 066004 Hebei Peoples R China

A windlass driven heavy duty multifunctional billet tong was designed for large-scale forging and casting to reduce the number of auxiliary material handling devices in manufacturing workshops. To improve its mechanical performance and safety, a novel multi-objective topology optimization method for its curved arm is proposed in this paper. Firstly, the influence of different open angles and working frequencies for the curved arm was simplified to a multi-objective optimization problem. A comprehensive evaluation function was constructed using the compromise programming method, and a mathematical model of multi-objective topology optimization was established. Meanwhile, a radar chart was employed to portray the comparative measures of working conditions, the weight coefficient for each working condition was determined based on the corresponding enclosed areas, combining the stress indices, the displacement indices and the frequency indices of all working conditions. The optimization results showed that the stiffness and strength of the curved arm can be improved while its weight can be reduced by 10.77%, which shows that it is feasible and promising to achieve a lightweight design of the curved arm of a billet tong. The proposed method can be extended to other equipment with complex working conditions.

关键词： billet tong lightweight design multiple-objective optimization multiple working conditions topology optimization

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Optimal Allocation of Distributed Generation in Distribution System Considering Time Sequence Data and Low-carbon Economy

Optimal Allocation of Distributed Generation in Distribution...

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IEEE PES General Meeting

作者： Liu, Ke-yan Sheng, Wanxing Liu, Yuan China Elect Power Res Inst Power Distribut Dept Beijing Peoples R China

ISBN: (纸本)9781479964154

With the consideration of time sequence characteristics of load and distributed generation (DG), a novel method is presented for optimal sitting and sizing of DG in distribution system. multiple-objective functions have been formed with the consideration of minimum investment and operational cost of DG, minimum voltage deviation and maximal voltage stability margin. To solve the multiple-objective optimization problem, an Improved Non-dominated Sorting Genetic Algorithm II (INSGA-II) has been proposed. Several experiments have been made on the modified PG&E 69-bus and actual 292-bus test systems. The result and comparisons indicate the proposed method for optimal placement and sizing of DG units is feasible and effective.

关键词： Optimal allocation distribution generation distribution system planning multiple-objective optimization

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Localization of Interference Sources in LTE Mobile Networks 4

Localization of Interference Sources in LTE Mobile Networks

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4th International Conference on Communication and Information Systems (ICCIS)

作者： Jiang, Tingjuan Ye, Wen Yin, Jingping Xiong, Shengxiang Jin, Haijia Beijing Univ Posts & Telecommun Sch Comp Sci Beijing Peoples R China

ISBN: (纸本)9781728162973

Interference seriously affects wireless signal transmission and degrades the quality of services in LTE mobile communication networks. In a dense urban environment, extra-network interference signals undergo multipath and non-light-of-sight propagation, and it is urgent but difficult for network operators to localize the interference sources quickly and accurately. This paper proposes a method of using propagation path analysis to localize extra-network interference sources. The method selects the measurement points with strong received signal strengths from frequency-sweeping measurement reports, employs reverse ray tracing to generate possible line-of-sight, non-line-of-sight, and multipath signal propagation trajectories between the candidate inference sources and the measurement points, and then takes multi-objective optimization to position the interference sources. We use practical LTE network data to conduct simulations to evaluate the proposed localization scheme. The results show that in a dense urban environment, the path-analysis-based interference localization can achieve positioning accuracy with deviation within 50 meters and therefore provides an efficient means for interference troubleshooting in LTE networks.

关键词： LTE network interference localization ray tracing propagation path multiple-objective optimization

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Optimal selection of encoding configuration for scalable video coding

Optimal selection of encoding configuration for scalable vid...

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IEEE International Conference on Image Processing (ICIP 2007)

作者： Abanoz, T. Berkin Tekalp, A. Murat Koc Univ Coll Engn TR-34450 Istanbul Turkey

ISBN: (纸本)9781424414369

It is well-known that the wider the range of extraction points a scalable bitstrearn supports, the lower the compression efficiency at these extraction points. Moreover, this compression efficiency generally varies according to what combination of scalability types are used to support this range of extraction points as specified by the encoding configuration. Hence, we propose some objective criteria as a measure of coverage, compression efficiency and rate-distortion performance of a configuration, and then present a multiple-objective optimization formulation to select the best encoding configuration for scalable video coding, given a range of bitstreams that must be supported. The method is demonstrated by experimental results.

关键词： scalable video coding encoding configuration multiple-objective optimization

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Symbolic Encoding of Reliability for the Design of Redundant Architectures 5

Symbolic Encoding of Reliability for the Design of Redundant...

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IEEE 5th International Conference on Industrial Cyber-Physical Systems (ICPS)

作者： Tierno, Antonio Turri, Giuliano Cimatti, Alessandro Passerone, Roberto Univ Trento Dipartimento Ingn & Sci Informaz Trento Italy Fdn Bruno Kessler Embedded Syst Trento Italy

ISBN: (纸本)9781665497701

In this paper, we propose an approach to automatic optimization of redundant embedded system architectures. Given a high-level description of a system and a library of redundant design patterns, all valid redundant alternative architectures are considered. Then, a model of the deviation of the architecture from its nominal behavior is built, and the set of all fault configurations, also referred to as "cut sets", is computed. This can be used to extract a reliability function for the architecture under study. We leverage the power of Satisfiability Modulo Theory to encode the problem with a symbolic technique, and use the reliability function, together with the assessment of other design objectives, to compare different redundant configurations, thus supporting the exploration of the design space.

关键词： Embedded systems fault-tolerance redundancy allocation reliability analysis design space exploration automatic synthesis multiple-objective optimization

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