检索结果-内蒙古大学图书馆

Compact U-Array MIMO Antenna Designs Using iwo algorithm

INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING 2009年第5期19卷 568-576页

作者： Mallahzadeh, A. R. Es'haghi, S. Hassani, H. R. Shahed Univ Dept Engn Tehran Iran

In this article, design of a novel compact four-channel multiple input multiple output (MIMO) antenna is described. The antenna is composed of four U-shaped patch elements and operates at 5.8 GHz. The single U-shaped patch antenna, to operate at this frequency, is designed using the Invasive Weed optimization algorithm. This algorithm is then applied to design two and four-channel MIMO antenna arrays for high degree of isolation. To measure the array performance under MIMO signaling conditions, a multiport metric is used to characterize the compact array rather than the scattering matrix characterization. The measurement and simulation results of reflection coefficient, mutual coupling, and radiation pattern are presented and discussed. (C) 2009 Wiley Periodicals, Inc. Int J RF and Microwave CAE 19: 568-576, 2009.

关键词： U shaped patch antenna MIMO system iwo algorithm

来源：评论

学校读者我要写书评

暂无评论

Design of a Meander-Shaped MIMO Antenna Using iwo algorithm for Wireless Applications

引用

APPLIED COMPUTATIONAL ELECTROMAGNETICS SOCIETY JOURNAL 2010年第7期25卷 631-638页

作者： Bahreini, Batol Mallahzadeh, Alireza Soleimani, Mohammad Iran Univ Sci & Technol Dept Elect Engn Tehran Iran Shahed Univ Dept Elect Engn Tehran Iran

Using a MIMO antenna system is a well-known technique to enhance the performance of wireless communication systems. In order to create a MIMO antenna system on a wireless device, two or more antenna elements could be placed in a very small space. Thus, the mutual coupling including radiation pattern coupling between closely arrayed antenna elements causes the decrease of a MIMO antenna performance. It means that we must consider not only the antenna size but also the suitable antenna array method to design the MIMO antenna system. The aim of this research was to design an antenna for a four-channel multiple input multiple output (MIMO) system that works at 5.8 GHz with consideration of the mutual coupling. The geometry of the antenna is optimized by using Invasive Weed Optimization algorithm to accomplish high degree of isolation. The measurement and simulation results of reflection coefficient, mutual coupling and radiation pattern are presented and discussed.

关键词： Antenna iwo algorithm MIMO systems

来源：评论

学校读者我要写书评

暂无评论

Design of a Broadband Cosecant Squared Pattern Reflector Antenna Using iwo algorithm

引用

IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 2013年第7期61卷 3895-3900页

作者： Dastranj, Aliakbar Abiri, Habibollah Mallahzadeh, Alireza Shiraz Univ Sch Elect & Comp Engn Shiraz *** Iran Shahed Univ Dept Elect Engn Tehran *** Iran

A cosecant squared pattern reflector antenna fed by a pyramidal double-ridged horn for 2-18 GHz is presented. Invasive weed optimization (iwo) algorithm is used for synthesizing the point source doubly curved reflector antenna. iwo method makes antenna synthesis flexible to achieve extra desired features such as low side lobe level (SLL) and low ripples in the shaped beam region. The simulation results via FEKO software package further prove the validity and versatility of this technique for solving reflector synthesis problems. In addition, experimental investigations are conducted to understand the complete reflector antenna system behaviors. Good agreement between the simulation and measurement has been achieved. The ripple in the cosecant squared region and the SLL is less than 1.5 dB and -25 dB, respectively. Based on the obtained results, the proposed reflector antenna can be used in broadband surveillance-search radar systems.

关键词： Cosecant squared pattern GO method iwo algorithm pattern ripple reflector antenna

来源：评论

学校读者我要写书评

暂无评论

Optimization of water distribution networks using hybrid BBO-iwo algorithm

引用

URBAN WATER JOURNAL 2023年第2期20卷 205-222页

作者： Batmaz, Veli Kayaalp, Necati Sirnak Univ Engn Fac Civil Engn Dept Div Hydraul Sirnak Turkey Dicle Univ Engn Fac Civil Engn Dept Div Hydraul Diyarbakir Turkey

Due to the increasing population and the pollution of existing water resources because of various factors, the need for water in the world is increasing. This requires building additional water distribution systems along with rehabilitation of existing systems. The cost of transmission and distribution constitutes more than half of the total cost of water supply systems. For this reason, by the optimum design of pipeline systems, the cost of water supply can be reduced. In this study, the optimization of pipe diameters in three networks, Two- Loop, Hanoi and GoYang, was carried out by a combination of two metaheuristic algorithms, namely Biogeography based optimization (BBO) and invasive weed optimization (iwo) under the same constraints. In addition, the Combined Gravity Network was successfully optimized with the current method for the first time in the literature.

关键词： EPANET-MATLAB toolkit water distribution networks optimization BBO algorithm iwo algorithm

来源：评论

学校读者我要写书评

暂无评论

Optimizing fracture toughness estimation for rock structures: A soft computing approach with GWO and iwo algorithms

引用

MEASUREMENT 2024年 238卷

作者： Fattahi, Hadi Ghaedi, Hossein Armaghani, Danial Jahed Arak Univ Technol Fac Earth Sci Engn Arak Iran Univ Technol Sydney Sch Civil & Environm Engn Sydney NSW 2007 Australia

The importance of mode I fracture toughness (KIc) K Ic ) lies in its role in studying rock fractures, finding application across diverse sectors like mining, tunneling, and surface construction. Given the time-consuming, costly, and arduous nature of determining fracture toughness through lab and field tests, employing indirect techniques is advised. Soft computing's indirect methods excel at modeling intricate nonlinear connections with optimal efficiency and accuracy, even when geological parameters introduce uncertainty. The innovative aspect of this research lies in leveraging Grey Wolf Optimization (GWO) and Invasive Weed Optimization (iwo) algorithms to model 88 Chevron Notched Brazilian Disc (CCNBD) specimens, designated by ISRM, considering uncertainties. The input parameters encompass uniaxial tensile strength (6t), t ), initial crack length (alpha 0), 0 ), disc specimen radius (R), R ), crack length (alpha B), B ), disc thickness (B), B ), and final crack length (alpha 1). 1 ). The research proceeds by employing 80% of the dataset (70 data points) for constructing models via the algorithms, reserving the remaining 20% (18 data points) for model validation. The outcomes, evaluated using statistical metrics such as mean square error (MSE), squared correlation coefficient (R2), mean absolute error (MAE), and root mean square error (RMSE) underscore the exceptional accuracy and performance of GWO and iwo algorithms in predicting and estimating rock structure's KIc. Ic . Moreover, this paper conducts a sensitivity analysis on K I c estimation's input parameters using @RISK software. Findings reveal that among the input parameters, 6t t exerts the most substantial influence on the model's output. Consequently, even a minor alteration in 6t t yields significant fluctuations in the relationship's output.

关键词： Fracture Toughness Rock Structures GWO algorithm iwo algorithm Sensitivity Analysis

来源：评论

学校读者我要写书评

暂无评论

An Effective and Efficient Hybrid algorithm Based on HS-iwo for Global Optimization

引用

INTERNATIONAL JOURNAL OF PATTERN RECOGNITION AND ARTIFICIAL INTELLIGENCE 2018年第4期32卷 1859006-1859006页

作者： Ouyang, Aijia Peng, Shuo Peng, Xuyu Wang, Qian Zunyi Normal Univ Dept Informat Engn Zunyi 563006 Guizhou Peoples R China Guangxi High Sch Key Lab Complex Syst & Computat Nanning 530006 Peoples R China Jinggangshan Univ Sch Elect & Informat Engn Jian 343009 Jiangxi Peoples R China

Considering that the invasive weed optimization (iwo) algorithm and the harmony search (HS) algorithm are inclined to fall into local optima with low convergence precision when they are used to deal with complex function optimization problems, this paper proposes a hybrid algorithm, HS-iwo algorithm, which is combined HS algorithm and iwo algorithm. We introduce strategies such as fixing the number of seeds, reinitializing limit solutions, multi-individual global HS, parameter optimization, etc. In order to make the two algorithms take advantage of their merits, they are mixed organically in this paper. Through tests on some complex functions of benchmark, the experimental results display that the HS-iwo algorithm has the efficiency and robustness of the algorithms. It is an optimization algorithm that is highly effective and stable, especially to be applied to the optimization of complicated functions compared with other intelligent optimization algorithms.

关键词： iwo algorithm HS algorithm multi-individual mixed mechanism HS-iwo

来源：评论

学校读者我要写书评

暂无评论

Invasive weed optimization based scheduling for digital microfluidic biochip operations

引用

INTEGRATION-THE VLSI JOURNAL 2021年 76卷 122-134页

作者： Rajesh, Kolluri Pyne, Sumanta Natl Inst Technol Dept Comp Sci & Engn Rourkela 769008 Odisha India

Digital Microfluidic Biochips (DMFBs) based on electro-wetting-on-dielectric (EWOD) technology are a class of lab-on-a-chip (LOC) devices. DMFBs can efficiently carry out biochemical analysis and have many advantages over the traditional laboratory system. DMFBs offer miniaturization, automation, and programmability. Resource-constrained scheduling is the first and vital step of fluidic-level synthesis of DMFBs while the other two are placement and routing of droplets. Scheduling DMFB operations is a constrained optimization problem which is NP-Complete. We propose an invasive weed optimization (iwo) algorithm based scheduling for the synthesis of DMFBs. The iwo algorithm is a nature-inspired meta-heuristic algorithm. Proposed algorithm can be used for the offline synthesis of DMFBs, where solution quality is more important than execution time. Each weed in the proposed algorithm represents a potential candidate solution for the scheduling problem. To calculate the fitness of individual weeds, we proposed an algorithm based on Heterogeneous Earliest Finish Time (HEFT), which incorporates resource binding, scheduling, and greedy module selection mechanism for bio-assay operations. Weeds (solutions) update their positions (priorities) by colonization behavior of weeds. Simulation results show that proposed iwo outperforms iterative improvement based algorithms and optimal ILP based algorithms which are existing for the offline synthesis of DMFBs.

关键词： Digital microfluidic biochips Earliest finish time High-level synthesis iwo algorithm Lab-on-a-chip Scheduling

来源：评论

学校读者我要写书评

暂无评论

Application of a novel iwo to the design of encoding sequences for DNA computing

引用

COMPUTERS & MATHEMATICS WITH APPLICATIONS 2009年第11-12期57卷 2001-2008页

作者： Zhang, Xuncai Wang, Yanfeng Cui, Guangzhao Niu, Ying Xu, Jin Huazhong Univ Sci & Technol Res Inst Biomol Comp Wuhan 430074 Peoples R China Zhengzhou Univ Light Ind Sch Elect & Elect Engn Zhengzhou 450002 Peoples R China

Encoding and processing information in DNA-, RNA- and other biomolecule-based devices is an important requirement for DNA based computing with potentially important applications. To make DNA computing more reliable, much work has focused on designing the good DNA sequences. However, this is a bothersome task as encoding problem is an NP problem. In this paper, a new methodology based on the iwo algorithm is developed to optimize encoding sequences. Firstly, the mathematics models of constrained objective optimization design for encoding problems based on the thermodynamic criteria are set up. Then, a modified iwo method is developed by defining the colonizing behavior of weeds to overcome the obstacles of the original iwo algorithm, which cannot be applied to discrete problems directly. The experimental results show that the proposed method is effective and convenient for the user to design and select effective DNA sequences in silicon for controllable DNA computing. Crown Copyright (c) 2008 Published by Elsevier Ltd. All rights reserved.

关键词： Encoding DNA sequences iwo algorithm DNA computing Fitness function

来源：评论

学校读者我要写书评

暂无评论

Job rotation scheduling in the Seru system: shake enforced invasive weed optimization approach

引用

ASSEMBLY AUTOMATION 2020年第3期40卷 461-474页

作者： Ayough, Ashkan Hosseinzadeh, Mohammad Motameni, Alireza Shahid Beheshti Univ Fac Management & Accounting Dept Ind Management Tehran Iran Iran Ctr Management Studies Tehran Iran

Purpose Line-cell conversion and rotation of operators between cells are common in lean production systems. Thus, the purpose of this study is to provide an integrated look at these two practices through integrating job rotation scheduling and line-cell conversion problems, as well as investigating the effect of rotation frequency on flow time of a Seru system. Design/methodology/approach First, a nonlinear integer programming model of job rotation scheduling problem and line-cell conversion problem (Seru-JRSP) was presented. Then, because Seru-JRSP is NP-hard, an efficient and effective invasive weed optimization (iwo) algorithm was developed. Exploration process of iwo was enhanced by enforcing two shake mechanisms. Findings Computations of various sample problems showed shorter flow time and less number of assigned operators in a Seru system scheduled through job rotation. Also, nonlinear behavior of flow time versus number of rotation periods was shown. It was demonstrated that, setting number of rotation frequency to one in line with the literature leads to inferior flow time. In addition, ability of developed algorithm to generate clusters of equivalent solutions in terms of flow time was shown. Originality/value In this research, integration of job rotation scheduling and line-cell conversion problems was introduced, considering lack of an integrated look at these two practices in the literature. In addition, a new improved iwo equipped with shake enforcement was introduced.

关键词： iwo algorithm Job rotation scheduling Lingo 17 Seru production system

来源：评论

学校读者我要写书评

暂无评论

Pattern synthesis for multi-feed reflector antennas using invasive weed optimisation

引用

IET MICROWAVES ANTENNAS & PROPAGATION 2012年第14期6卷 1583-1589页

作者： Foudazi, A. Mallahzadeh, A. R. Shahed Univ Elect & Elect Engn Dept Tehran Iran

The authors present a new optimisation method for pattern synthesis of multi-feed reflector antennas in this study. By using an invasive weed optimisation (iwo) algorithm, shaped beam antennas are designed. The results of the iwo algorithm for the synthesis of cosecant squared and contoured beam patterns are presented and compared with particle swarm optimisation algorithm results. The far-field radiation patterns of reflector antennas, fed by linear and planar array of conical horn antennas, are provided by a physical optics and the error between desired and provided radiation patterns is calculated by a root mean square method. The results show that the iwo algorithm, which provides good convergence, is stable and adaptive-to-change for different boundary conditions in pattern synthesis applications.

关键词： conical horn antennas particle swarm optimisation Optimisation techniques contoured beam pattern synthesis iwo algorithm horn antennas Antenna accessories planar antenna arrays physical optics particle swarm optimisation algorithm conical antennas far-field radiation patterns planar antenna array mean square error methods shaped beam antennas Antenna arrays invasive weed optimisation method antenna radiation patterns Interpolation and function approximation (numerical analysis) cosecant squared pattern synthesis root mean square method reflector antenna feeds linear antenna array multifeed reflector antennas linear antenna arrays

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：