检索结果-内蒙古大学图书馆

AN objective function FOR OPTIMIZATION TECHNIQUES IN SIMULTANEOUS MULTIPLE-ELEMENT ANALYSIS BY INDUCTIVELY COUPLED PLASMA SPECTROMETRY

引用

APPLIED SPECTROSCOPY 1982年第1期36卷 37-40页

作者： LEARY, JJ BROOKES, AE DORRZAPF, AF GOLIGHTLY, DW US GEOL SURVEY RESTONVA 22092

This work considers several composite objective functions and uses the sequential simplex optimization technique to evaluate the performance of a proposed objective function in locating optimal instrumental operating conditions for simultaneous multiple-element determinations by inductively coupled plasma spectrometry. The proposed objective function, combined with a generalized approach to optimization, can be applied to any group of analysis elements and is of value in routine optimization procedures for simultaneous multiple-element methods of analysis.

关键词： Analysis of geologic materials Emission spectroscopy Optimization objective function

来源：评论

学校读者我要写书评

暂无评论

objective function based ranking method for selection of optimal beam angles in IMRT

引用

PHYSICA MEDICA-EUROPEAN JOURNAL OF MEDICAL PHYSICS 2020年第0期69卷 44-51页

作者： Ramar, Natarajan Meher, S. R. Ranganathan, Vaitheeswaran Perumal, Bojarajan Kumar, Prashant Anto, Gipson Joe Etti, S. Harikrishna Philips India Ltd Philips Hlth Syst Bangalore Karnataka India Vellore Inst Technol Sch Adv Sci Dept Phys Vellore Tamil Nadu India Bharathiar Univ Dept Med Phys Coimbatore Tamil Nadu India

We propose a novel method for the selection of optimal beam angles in Intensity Modulated Radiation Therapy (IMRT). The proposed approach uses an objective function based metric called "target-to-critical organ objective function ratio" to find out the optimal gantry angles. The beams are ranked based on this metric and are accordingly chosen for IMRT optimization. We have used the Pinnacle TPS (Philips Medical System V 16.2) for performing the IMRT optimization. In order to validate our approach, we have applied it in four clinical cases: Head and Neck, Lung, Abdomen and Prostate. Basically, for all clinical cases, two set of plans were created with same clinical objectives, namely Equal angle plan (EA Plan) and Suitable angle Plan (SA Plan). In the EA plans, the beam angles were placed in an equiangular manner starting from the gantry angle of 0 degrees. In the corresponding SA plans, the beam angles were decided using the guidance provided by the algorithm. The reduction in OAR mean dose and max dose obtained in SA plans is about 3 to 16% and 3 to 15% respectively depending upon the treatment site while obtaining equal target coverage as compared to their EA counterparts. It takes approximately 15-25 min to find the optimal beam angles. The results obtained from the clinical cases indicate that the plan quality is considerably improved when the beam angles are optimized using the proposed method.

关键词： IMRT BAO objective function Beam angles

来源：评论

学校读者我要写书评

暂无评论

Fine-tuning property domain weighting factors and the objective function in force-field parameter optimization

引用

Journal of Molecular Graphics and Modelling 2025年 139卷

作者： Strickstrock, Robin Hagg, Alexander Hülsmann, Marco Kirschner, Karl N. Reith, Dirk University of Applied Sciences Bonn-Rhein-Sieg Grantham-Allee 20 Sankt Augustin53757 Germany University of Applied Sciences Bonn-Rhein-Sieg Grantham-Allee 20 Sankt Augustin53757 Germany

Force field (FF) based molecular modeling is an often used method to investigate and study structural and dynamic properties of (bio-)chemical substances and systems. When such a system is modeled or refined, the force-field parameters need to be adjusted. This force-field parameter optimization can be a tedious task and is always a trade-off in terms of errors regarding the targeted properties. To better control the balance of various properties’ errors, in this study we introduce weighting factors for the optimization objectives. Different weighting strategies are compared to fine-tune the balance between bulk-phase density and relative conformational energies (RCE), using n-octane as a representative system. Additionally, a non-linear projection of the individual property-specific parts of the optimized loss function is deployed to further improve the balance between them. The results show that the combined error for the reproduction of the properties targeted in this optimization is reduced. Furthermore, the transferability of the force field parameters (FFParams) to chemically similar systems is increased. One interesting outcome is a large variety in the resulting optimized FFParams and corresponding errors, suggesting that the optimization landscape is multi-modal and very dependent on the weighting factor setup. We conclude that adjusting the weighting factors can be a very important feature to lower the overall error in the FF optimization procedure, giving researchers the possibility to fine-tune their FFs. © 2025 The Authors

关键词： Force field models Lennard-Jones parameters Multiscale parameterization Local optimization Gradient-based optimization Weighting factors objective function Non-linear projection

来源：评论

学校读者我要写书评

暂无评论

objective function Selection for Array Optimization Using Principal Component Regression

Objective Function Selection for Array Optimization Using Pr...

引用

IEEE International Ultrasonics Symposium (IEEE IUS)

作者： Xi, Ze Wang, Xiangang Luo, Xiaowei Tsinghua Univ Inst Nucl & New Energy Technol Collaborat Innovat Ctr Adv Nucl Energy Technol Key Lab Adv Reactor Engn & SafetyMinist Educ Beijing 100084 Peoples R China

ISBN: (纸本)9780738112091

The definition of objective functions is vital when optimizing parameters of an array or an acoustic field. However, the present selections are often qualitative or empirical, this may lead to imprecise optimization. In this paper, an objective function selection framework is proposed based on principal component regression method (PCR). A regression equation is built among inspection results and acoustic field characteristics. The remarkable acoustic characteristics are selected as objective functions in optimization. An inspection example using a linear array is simulated, the effectiveness of the framework is proven by the simulation. This work can be applied to medical ultrasonic and non-destructive testing domains.

关键词： ultrasonic array optimization objective function principal component regression

来源：评论

学校读者我要写书评

暂无评论

objective function for minimizing optical pathlength difference in design of flat-field holographic concave gratings 12

Objective function for minimizing optical pathlength differe...

引用

Conference on Holography, Diffractive Optics, and Applications XII Part of SPIE/COS Photonics Asia Conference

作者： Chen, Siyu Zeng, Lijiang Li, Lifeng Tsinghua Univ Dept Precis Instrument State Key Lab Precis Measurement Technol & Instru Beijing 100084 Peoples R China

ISBN: (纸本)9781510657038;9781510657021

An objective function that closely represents the maximum optical pathlength difference on the entire grating surface for designing a flat-field holographic concave grating is proposed. Compared to design methods that minimize certain aberration coefficients of the optical pathlength function, the present objective function has a clearer physical meaning of optical pathlength difference and guarantees a smaller spot size. Compared to design methods that minimize the spot size based on ray tracing, the present method requires less computing time, but is equally effective in minimizing spot size, and it even provides a better image quality in the sagittal direction.

关键词： flat-field spectrometer holographic concave grating objective function optical pathlength difference

来源：评论

学校读者我要写书评

暂无评论

A Novel Separability objective function in CNN for Feature Extraction of SAR Images

引用

Chinese Journal of Electronics 2019年第2期28卷 423-429页

作者： GAO Fei WANG Meng WANG Jun YANG Erfu ZHOU Huiyu Department of Electronic and Information Engineering Beihang University Department of Design Manufacture and Engineering Management (DMEM) University of Strathclyde Department of Informatics University of Leicester

Convolutional neural network(CNN) has become a promising method for Synthetic aperture radar(SAR) target recognition. Existing CNN models aim at seeking the best separation between classes, but rarely care about the separability of them. We performs a separability measure by analyzing the property of linear separability, and proposes an objective function for CNN to extract linearly separable features. The experimental results indicate the output features are linearly separable,and the classification results are comparable with the other state of the art techniques.

关键词： Synthetic aperture radar(SAR) Convolution neural network(CNN) Classification Linear separability objective function

来源：评论

学校读者我要写书评

暂无评论

A Differential Game Based Approach Against objective function Attack in Cognitive Networks

引用

Chinese Journal of Electronics 2018年第4期27卷 879-888页

作者： FENG Guangsheng LIN Junyu ZHAO Qian WANG Huiqiang LYU Hongwu ZHAO Xiaoyu HAN Jizhong LI Bingyang College of Computer Science and Technology Harbin Engineering University Institute of Information Engineering Chinese Academy of Sciences School of Computer and Information Engineering Harbin University of Commerce

We study the problem of defense strategy against objective function attack(OFA) in Cognitive networks(CNs), where the network can be operated at the optimal state by adapting the parameters of its objective function. An OFA attacker can disrupt the parameter adaptation by interfering measures, which results in some operating parameters of the objective function deviating from their optimal settings. We first model the interactive process between the OFA attacker and defense system using differential game theory, and propose a defense strategy by introducing a new metric, namely, threat factor. Then,we obtain the optimal defense strategy by proving the existence of the saddle point of the proposed model. Moreover,this defense strategy is scale-free such that it can conquer a large number of OFAs in a decentralized way. Finally, we conduct extensive simulations to show that the proposed approach is effective.

关键词： Cognitive networks objective function Operating parameter Saddle point

来源：评论

学校读者我要写书评

暂无评论

Well production optimization using streamline features-based objective function and Bayesian adaptive direct search algorithm

引用

Petroleum Science 2022年第6期19卷 2879-2894页

作者： Qi-Hong Feng Shan-Shan Li Xian-Min Zhang Xiao-Fei Gao Ji-Hui Ni School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongChina Shandong Institute of Petroleum and Chemical Technology Dongying257061ShandongChina CNOOC China Limited Shenzhen BranchShenzhen518000GuangdongChina

Well production optimization is a complex and time-consuming task in the oilfield *** combination of reservoir numerical simulator with optimization algorithms is usually used to optimize well *** method spends most of computing time in objective function evaluation by reservoir numerical simulator which limits its optimization *** improve optimization efficiency,a well production optimization method using streamline features-based objective function and Bayesian adaptive direct search optimization(BADS)algorithm is *** new objective function,which represents the water flooding potential,is extracted from streamline *** only needs to call the streamline simulator to run one time step,instead of calling the simulator to calculate the target value at the end of development,which greatly reduces the running time of the *** the well production optimization model is established and solved by the BADS *** feasibility of the new objective function and the efficiency of this optimization method are verified by three *** demonstrate that the new objective function is positively correlated with the cumulative oil *** the BADS algorithm is superior to other common algorithms in convergence speed,solution stability and optimization ***,this method can significantly accelerate the speed of well production optimization process compared with the objective function calculated by other conventional *** can provide a more effective basis for determining the optimal well production for actual oilfield development.

关键词： Well production Optimization efficiency Streamline simulation Streamline feature objective function Bayesian adaptive direct search algorithm

来源：评论

学校读者我要写书评

暂无评论

A new objective function design for optimization of secondary controllers in load frequency control

JOURNAL OF THE FACULTY OF ENGINEERING AND ARCHITECTURE OF GA...

引用

JOURNAL OF THE FACULTY OF ENGINEERING AND ARCHITECTURE OF GAZI UNIVERSITY 2021年第4期36卷 2053-2067页

作者： Yilmaz, Zumre Yenen Bal, Gungor Celik, Emre Ozturk, Nihat Guvenc, Ugur Arya, Yogendra Duzce Univ Engn Fac Dept Elect & Elect Engn TR-81620 Duzce Turkey Gazi Univ Technol Fac Elect & Elect Engn Dept TR-06570 Ankara Turkey JC Bose Univ Sci & Technol YMCA Elect Engn Dept Faridabad 121006 Haryana India

In this study, load frequency control (LFC) of two-area non-reheat thermal power system and multi-source power systems is addressed. A simple PID-structured controller is used as a secondary controller in these systems. To raise the performance of PID controller, a new multi-objective function is designed and PID controller parameters are acquired by minimizing the value of this function with symbiotic organisms search (SOS) algorithm. All electrical power systems simulated are modeled in MATLAB/Simulink environment and the optimizer is coded in MATLAB/M-file platform. In order to affirm the contribution of the work, results collected from each power system are compared with popular results published in prestigious journals. As per the comparative results, despite its simplicity, SOS:PID controller tuned via the proposed objective function is observed to result in better performance than other approaches in terms of oscillations, settling time, maximum overshoot and maximum undershoot time domain indicators of the frequency and tie-line power change curves.

关键词： Load frequency control PID controller objective function two-area thermal power system multi-source power system

来源：评论

学校读者我要写书评

暂无评论

objective function: A Key Contributor in Internet of Things Primitive Properties

Objective Function: A Key Contributor in Internet of Things ...

引用

CSI International Symposium on Real-Time and Embedded Systems and Technologies

作者： Safaei, Bardia Monazzah, Amir Mahdi Hosseini Shahroodi, Taha Ejlali, Alireza Sharif Univ Technol Dept Comp Engn Tehran Iran

ISBN: (纸本)9781538614754

With the widespread use of Internet of Things (IoT) in every aspect of human's daily life, communications of such an enormous amount of existing embedded devices in these systems arise many new challenges from power consumption, performance, and reliability perspectives. Communications in an IoT infrastructure are managed by a set of policies which are determined by objective functions (OFs). Thus, OFs are the most important contributors in facing with the mentioned challenges. In this paper, due to the lack of information on how OFs affect the primary properties of an IoT infrastructure, we have compared three well-known OFs (OF0, MRHOF, and OFFL) from power consumption, performance, and reliability perspectives. This paper would pave the way for scholars to realize which of the three mentioned areas are more affected by OFs. Our evaluation results on Contiki's IoT simulation environment (COOJA) illustrate, OFs could affect the power consumption by up to 71.2%, while their impacts on reliability and performance would be as high as 77.5% and 25.15%, respectively.

关键词： Internet of Things LLN Routing Protocol RPL objective function Power Consumption Performance Reliability

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：