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On the gEUD biological optimization objective for organs at risk in Photon Optimizer of Eclipse treatment planning system

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JOURNAL OF APPLIED CLINICAL MEDICAL PHYSICS 2018年第1期19卷 106-114页

作者： Fogliata, Antonella Thompson, Stephen Stravato, Antonella Tomatis, Stefano Scorsetti, Marta Cozzi, Luca Humanitas Res Hosp & Canc Ctr Radiotherapy & Radiosurg Dept Milan Rozzano Italy Oncol Syst Varian Med Syst Palo Alto CA USA Humanitas Univ Biomed Fac Milan Rozzano Italy

Inverse planning optimization using biologically based objectives is becoming part of the intensity modulated optimization process. The performances and efficacy of the biologically based gEUD (generalized Equivalent Uniform Dose) objective implemented in the Photon Optimizer (PO) of Varian Eclipse treatment planning system have been here analyzed. gEUD is associated with the parameter a that accounts for the seriality of a structure, being higher for more serial organs. The PO was used to optimize volumetric modulated arc therapy (VMAT) plans on a virtual homogeneous cylindrical phantom presenting a target and an organ at risk (OAR). The OAR was placed at 4 mm, 1 and 2 cm distance, or cropped at 0, 2 and 4 mm from the target. Homogeneous target dose of 60 Gy in 20 fractions was requested with physical dose-volume objectives, while OAR dose was minimized with the upper gEUD objective. The gEUD specific a parameter was varied from 0.1 to 40 to assess its impact to OAR sparing and target coverage. Actual head and neck and prostate cases, with one parotid and the rectum as test OAR, were also analyzed to translate the results in the more complex clinical environment. Increasing the a parameter value in the gEUD objective, the optimization achieved lower volumes of the OAR which received the highest dose levels. The maximum dose in the OAR was minimized well with a values up to 20, while further increase of a to 40 did not further improve the result. The OAR mean dose was reduced for the OAR located at 1 and 2 cm distance from the target, enforced with increasing a. For cropped OARs, a mean dose reduction was achieved for a values up to 3-5, but mean dose increased for higher a values. The optimal choice of the parameter a depends on the mutual OAR and target position, and seriality of the organ. Today no significant compendium of clinical and biological specific a and gEUD values are available for a wide range of OARs.

关键词： biological optimization gEUD IMRT optimization objective VMAT

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Control of Discrete Event Systems by Using Symbolic Transition Model: An Application to Power Grids

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ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING 2025年第2期50卷 937-949页

作者： Ozbaltan, Mete Erzurum Tech Univ Comp Engn Erzurum Turkiye

In this paper, a new symbolic modeling framework is proposed for the control of discrete event systems (discrete controller synthesis). Reactive infinite-state systems are generally dynamic systems with inputs and outputs. Modeling the outputs in existing symbolic modeling methods for reactive infinite-state systems has not been extensively discussed in the literature. It is crucial to realistically model the outputs and obtain reliable controllers. One of the main contributions and innovations in this study is the ability to symbolically model their output. In this direction, symbolic transition models are offered, where events are defined as guarded symbolic transitions. The framework considers input/output reactive infinite-state systems to satisfy safety and optimization objectives. Effective algorithms and safety control policies are offered to solve the safety control problem (i.e., satisfy the safety objective) for input/output infinite-state systems. Another contribution in this work provides optimization targets within a given cost function based on state transitions, without specifying the target states. The framework is then applied to power grids to demonstrate the effectiveness of the symbolic transition models and experimentally evaluate the new control algorithms. The results showed that the approach is very effective compared to other approaches found in the literature. The computation times required to achieve both safety and optimization objectives are obtained relatively quickly compared to other deterministic methods found in the literature.

关键词： Symbolic discrete controller synthesis Safety objective optimization objective Power grids

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Analysis and Comparison of the Vibration Correction Accuracy of Different optimization objectives for the Classical Absolute Gravimeter

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IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT 2021年 70卷 1-10页

作者： Li, Zhenxing Wu, Kang Guo, Meiying Wen, Yi Chen, Yicong Wang, Lijun Tsinghua Univ State Key Lab Precis Measurement Technol & Instru Beijing 100084 Peoples R China Tsinghua Univ Dept Precis Instrument Beijing 100084 Peoples R China

Accurate absolute gravimeters are important instruments in applications, such as metrology, geophysics, and geological exploration. Vibration is one of the limiting factors that cause deterioration in measurement accuracy, which includes trueness and precision. The vibration correction method, in which a seismometer is used to record the vibration, provides an effective method to deal with the disturbances. The theoretical analysis shows that the ultimate correction accuracy is limited by the inherent frequency performance of the seismometer. The correction algorithm is an optimization problem to achieve this ultimate accuracy. The selection of the optimization objectives affects the correction accuracy dramatically. Although the real gravitational acceleration is unknown before the measurement is taken, minimization of the standard deviation of the fitting residual for a single drop (SDFRSD) is proven to realize better trueness. Enhanced precision is achieved through minimization of the Type A uncertainty of gravitational accelerations for all drops (UGAAD). Simulations and experimental measurements with the T-1 absolute gravimeter verify the theoretical analysis results. In addition, the results also show that the SDFRSD correction contains the real gravitational acceleration value, while the UGAAD correction exceeds the valid range. Therefore, the SDFRSD correction approach provides better comprehensive accuracy than the UGAAD correction method.

关键词： Absolute gravimeter accuracy analysis optimization objective vibration correction

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Heat transfer characteristics of topological latent heat storage systems based on optimization objectives

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APPLIED THERMAL ENGINEERING 2024年 252卷

作者： Zhang, Xinyu Yang, Xiaohong Gao, Xiaoyu Xu, Jiakun Inner Mongolia Univ Technol Sch Energy & Power Engn Hohhot 010051 Peoples R China Minist Educ Key Lab Wind & Solar Energy Utilizat Technol Hohhot 010051 Peoples R China Minist Educ Inner Mongolia Autonomous Reg New Energy Prod Prom Hohhot 010051 Peoples R China

In order to improve the heat storage efficiency and shorten the heat storage/release time in latent heat storage (LHS) systems, topology optimization of heat transfer problems has been applied to LHS systems. The choice of the optimization objective determines the structure of the topology fins. In this paper, the topology generation process was analyzed using the mean temperature, the mean square deviation (MSD) of the mean temperature, and the multi -objective entropy depletion as the optimization objectives. In this way, a method for selecting the optimization objectives according to the design requirements was obtained. The multi -objective topological structure (Case 3) with uniform tree -shaped fins (Case 4) and gradient tree -shaped fins (Case 5) was applied to the LHS system, and the finite element analysis method was used to construct a mathematical model of the LHS system to comprehensively analyze the heat storage/release process. The results showed that the complete melting times for Case 3, Case 4, and Case 5 were 751 s, 1005 s, and 920 s, respectively. At 751 s, the average heat storage capacities for Case 3, Case 4, and Case 5 are 296.81 W, 216.94 W, and 238.92 W, respectively. Compared to Case 4, Case 3 decreased the complete melting time by 25.27 % and increased the average heat storage capacity by 36.82 %. At heat -releasing times of 500 s, 1000 s, 1500 s, and 2000 s, the maximum differences in liquid phase rates for the three models were 10.93 %, 11.97 %, 11.51 %, and 9.57 %, respectively. From the perspective of the field synergy, Case 3 showed a better heat transfer path and the optimal heat transfer effect considering the temperature, liquid phase rate, heat storage/release time, and heat storage/release capacity. In addition, the dimensionless criterion equation affecting the liquid phase rate was obtained by segmented fitting of the heat transfer process of the topology -optimized LHS system. The findings of the study can facilitate the promo

关键词： Latent heat storage Topology Heat storage/release optimization objective Entransy Field synergy

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Akaike Information Criterion-based objective for Belief Rule Base optimization 8

Akaike Information Criterion-based Objective for Belief Rule...

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8th International Conference on Intelligent Human-Machine Systems and Cybernetics (IHMSC)

作者： Change, Leilei Wang, Liuying Wang, Wei Liu, Gu Ling, Xiaodong High Tech Inst Xian Dept Management Xian Peoples R China China Satellite Maritime Tracking & Control Lab Wuxi Peoples R China

ISBN: (纸本)9781509007684

With the ability in addressing different types of information under uncertainty, the belief rule base (BRB) has been an efficient tool in modeling the nonlinearity of practical systems, as well as taking the experts knowledge and experience into the modeling process. However, the modeling accuracy has been the sole objective for BRB training and learning in the parameter optimization process, which does not take the modeling complexity into consideration. The exclusion of the modeling complexity can directly cause the infeasibility for constructing and further optimizing the BRB system, especially with human's involvement. In this study, the Akaike Information Criterion (AIC) is used the replace the conventional mean square error (MSE) as the modeling objective. Through a thorough deduction process, the AIC-based objective can represent both modeling accuracy and complexity. Furthermore, the BRB parameter model and the corresponding algorithm are proposed as well. The proposed BRB optimization with AIC-based objective is validated by a numeric case study.

关键词： belief rule base akaike information criterion optimization objective optimization model optimization algorithm

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Optimizing Audio-Visual Speech Enhancement Using Multi-Level Distortion Measures for Audio-Visual Speech Recognition

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IEEE-ACM TRANSACTIONS ON AUDIO SPEECH AND LANGUAGE PROCESSING 2024年 32卷 2508-2521页

作者： Chen, Hang Wang, Qing Du, Jun Yin, Bao-Cai Pan, Jia Lee, Chin-Hui Univ Sci & Technol China Natl Engn Res Ctr Speech & Language Informat Proc Hefei 230026 Peoples R China iFLYTEK Res Hefei 230088 Peoples R China Georgia Inst Technol Sch Elect & Comp Engn Atlanta GA 30332 USA

A multi-level distortion measure (MLDM) is proposed as an objective to optimize deep neural network-based speech enhancement (SE) in both audio-only and audio-visual scenarios. The aim is to achieve simultaneous performance improvements in speech quality, intelligibility, and recognition error reductions. Moreover, a comprehensive correlation analysis shows that these three evaluation metrics exhibit high Pearson correlation coefficient (PCC) values with three commonly used optimization objectives: the mean squared error between the ideal ratio and estimated magnitude masks, scale-invariant signal-to-noise ratio, and cross-entropy-guided measure. To further improve the performance, we leverage the complementarities of the three objectives and propose another correlated multi-level distortion measure (C-MLDM) defined as a weighted combination of MLDM and an average correlation measure based on the three PCCs. Experimental results on the TCD-TIMIT corpus corrupted by additive noise demonstrate that MLDM outperforms systems optimized with each objective in both audio-visual and audio-only scenarios, offering improved performances in all three metrics: speech quality, intelligibility, and recognition performance. C-MLDM also consistently outperforms MLDM in all test cases. Finally, the generalizability of both MLDM and C-MLDM is confirmed through extensive testing across diverse datasets, SE model architectures, and linguistic conditions.

关键词： Audio-visual optimization objective robust speech recognition speech enhancement task-generic

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Manifold regularized discriminative feature selection for multi-label learning

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PATTERN RECOGNITION 2019年 95卷 136-150页

作者： Zhang, Jia Luo, Zhiming Li, Candong Zhou, Changen Li, Shaozi Xiamen Univ Dept Cognit Sci Xiamen 361005 Fujian Peoples R China Xiamen Univ Postdoc Ctr Informat & Commun Engn Xiamen 361005 Fujian Peoples R China Fujian Univ Tradit Chinese Med Coll Tradit Chinese Med Fuzhou 350122 Fujian Peoples R China

In multi-label learning, objects are essentially related to multiple semantic meanings, and the type of data is confronted with the impact of high feature dimensionality simultaneously, such as the bioinformatics and text mining applications. To tackle the learning problem, the key technology, i.e., feature selection, is developed to reduce dimensionality, whereas most of the previous methods for multi-label feature selection are either directly transformed from traditional single-label feature selection methods or half-baked in the label information exploitation, and thus causing the redundant or irrelevant features involved in the selected feature subset. Aimed to seek discriminative features across multiple class labels, we propose an embedded multi-label feature selection method with manifold regularization. To be specific, a low-dimensional embedding is constructed based on the original feature space to fit the label distribution for capturing the label correlations locally, which is also constrained using the label information in consideration of the co-occurrence relationships of label pairs. Following this principle, we design an optimization objective function involving l(2,1)-norm regularization to achieve multi-label feature selection, and the convergence is guaranteed. Empirical studies on various multi-label data sets reveal that the proposed method can obtain highly competitive performance against some state-of-the-art multi-label feature selection methods. (C) 2019 Elsevier Ltd. All rights reserved.

关键词： Multi-label learning Feature selection Label correlations Manifold regularization optimization objective

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Multilabel Feature Selection Based on Fuzzy Mutual Information and Orthogonal Regression

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IEEE TRANSACTIONS ON FUZZY SYSTEMS 2024年第9期32卷 5136-5148页

作者： Dai, Jianhua Liu, Qi Chen, Wenxiang Zhang, Chucai Hunan Normal Univ Hunan Prov Key Lab Intelligent Comp & Language Inf Changsha 410081 Peoples R China Hunan Normal Univ Coll Informat Sci & Engn Changsha 410081 Peoples R China

With the increase of high-dimensional multilabel data, multilabel feature selection (MFS) has received more and more widespread attention. Embedded feature selection methods have been widely studied due to their high efficiency and low computational cost. Fuzzy mutual information, as an effective tool for processing continuous features, is widely used in filter feature selection, which results in many repeated entropy calculations. Most of the existing multilabel embedded feature selection methods are based on least squares regression, which loses a lot of statistical and structural information. To solve the above-mentioned problems, we established an optimization framework based on fuzzy mutual information that considers global correlation to obtain the weight of each feature. Under this framework, many repeated entropy operations are avoided. Then, the weight of each feature is introduced into the orthogonal regression optimization framework as prior knowledge. Finally, two optimization frameworks are comprehensively considered for MFS. Furthermore, considering the characteristics of multilabel data, we extend the proposed method to feature-specific MFS. We conducted sufficient experiments to demonstrate the efficiency of our proposed method.

关键词： Correlation Mutual information Feature extraction optimization Redundancy Fuzzy systems Vectors Feature selection fuzzy rough sets multilabel learning mutual information optimization objective

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Optimum placement of piezoelectric ceramic modules for vibration suppression of highly constrained structures

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SMART MATERIALS AND STRUCTURES 2007年第5期16卷 1662-1671页

作者： Belloli, Alberto Ermanni, Paolo ETH Ctr Struct Technol CH-8092 Zurich Switzerland

The vibration suppression efficiency of so-called shunted piezoelectric systems is decisively influenced by the number, shape, dimensions and position of the piezoelectric ceramic elements integrated into the structure. This paper presents a procedure based on evolutionary algorithms for optimum placement of piezoelectric ceramic modules on highly constrained lightweight structures. The optimization loop includes the CAD software CATIA V5, the FE package ANSYS and DynOPS, a proprietary software tool able to connect the Evolving Object library with any simulation software that can be started in batch mode. A user-defined piezoelectric shell element is integrated into ANSYS 9.0. The generalized electromechanical coupling coefficient is used as the optimization objective. Position, dimensions, orientation, embedding location in the composite lay-up and wiring of customized patches are determined for optimum vibration suppression under consideration of operational and manufacturing constraints, such as added mass, maximum strain and requirements on the control circuit. A rear wing of a racing car is investigated as the test object for complex, highly constrained geometries.

关键词： .patches ETH Zurich maximum strain vibration suppression Optimum placement piezoelectric ceramic elements optimization loop DynOPS generalized electromechanical coupling optimization objective

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Multi-institutional evaluation of knowledge-based planning performance of volumetric modulated arc therapy (VMAT) for head and neck cancer

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PHYSICA MEDICA-EUROPEAN JOURNAL OF MEDICAL PHYSICS 2019年 64卷 174-181页

作者： Kamima, Tatsuya Ueda, Yoshihiro Fukunaga, Jun-ichi Shimizu, Yumiko Tamura, Mikoto Ishikawa, Kazuki Monzen, Hajime Canc Inst Hosp Japanese Fdn Canc Res Radiat Oncol Dept Tokyo 1358550 Japan Osaka Int Canc Inst Dept Radiat Oncol Chuo Ku 3-1-69 Otemae Osaka 5378567 Japan Kyushu Univ Hosp Dept Med Technol Div Radiol Higashi Ku Fukuoka Fukuoka 8128582 Japan Seirei Hamamatsu Gen Hosp Dept Radiol 2-12-12 Sumiyoshi Hamamatsu Shizuoka 4308558 Japan Kindai Univ Dept Med Phys Grad Sch Med Sci 377-2 Ohno Higashi Osaka 5898511 Japan Kindai Univ Fac Med Dept Radiat Oncol 377-2 Ohno Higashi Osaka 5898511 Japan

Purpose: The aim of this study was to investigate whether additional manual objectives are necessary for the RapidPlan (RP) with a single optimization. We conducted multi-institutional comparisons of plan quality for head and neck cancer (HNC) using the models created at each institute. Methods: The ability of RP to produce acceptable plans for dose requirements was evaluated in two types of oropharynx cancers at five institutes in Japan. Volumetric modulated arc therapy plans created without (RP plan) and with additional manual objectives (M-RP plan) were compared in terms of planning target volume (PTV), brainstem, spinal cord and parotid glands in dosimetric parameters. Results: There were no major dosimetric PTV differences between RP and M-RP plans. For the brainstem and spinal cord in the RP plans, only 40% and 30% of the plans achieved the dose requirements, while the M-RP plans with upper objective added to volume 0% at all institutes achieved them for 90% of the plans. For the L-parotid gland, there was no difference in the RP and M-RP plans (both were 40%) in achieving the acceptable criteria. For the R-parotid gland, 60% and 80% of the RP and M-RP plans achieved the constraint criteria, and in terms of the achievement rate, the RP plans were relatively high. Conclusions: M-RP plans did not require reoptimization;only an upper objective was needed for the brainstem and spinal cord, while the parotid gland dose was reduced in both RP plans with the auto generated line objectives alone.

关键词： Knowledge-based planning RapidPlan Head and neck cancer optimization objective

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