检索结果-内蒙古大学图书馆

Co-expression network analysis and genetic algorithms for gene prioritization in preeclampsia

BMC MEDICAL GENOMICS 2013年第1期6卷 1-10页

作者： Tejera, Eduardo Bernardes, Joao Rebelo, Irene Univ Porto Inst Mol & Cell Biol IBMC P-4100 Oporto Portugal Univ Porto Fac Med Ctr Res Hlth Technol & Informat Syst CINTESIS P-4100 Oporto Portugal Sao Joao Hosp Porto INEB Inst Biomed Engn Dept Obstet & Gynecol Oporto Portugal Univ Porto Fac Pharm Dept Biol Sci Lab Biochem P-4100 Oporto Portugal

Background: In this study, we explored the gene prioritization in preeclampsia, combining co-expression network analysis and genetic algorithms optimization approaches. We analysed five public projects obtaining 1,146 significant genes after cross-platform and processing of 81 and 149 microarrays in preeclamptic and normal conditions, respectively. Methods: After co-expression network construction, modular and node analysis were performed using several approaches. Moreover, genetic algorithms were also applied in combination with the nearest neighbour and discriminant analysis classification methods. Results: Significant differences were found in the genes connectivity distribution, both in normal and preeclampsia conditions pointing to the need and importance of examining connectivity alongside expression for prioritization. We discuss the global as well as intra-modular connectivity for hubs detection and also the utility of genetic algorithms in combination with the network information. FLT1, LEP, INHA and ENG genes were identified according to the literature, however, we also found other genes as FLNB, INHBA, NDRG1 and LYN highly significant but underexplored during normal pregnancy or preeclampsia. Conclusions: Weighted genes co-expression network analysis reveals a similar distribution along the modules detected both in normal and preeclampsia conditions. However, major differences were obtained by analysing the nodes connectivity. All models obtained by genetic algorithm procedures were consistent with a correct classification, higher than 90%, restricting to 30 variables in both classification methods applied. Combining the two methods we identified well known genes related to preeclampsia, but also lead us to propose new candidates poorly explored or completely unknown in the pathogenesis of preeclampsia, which may have to be validated experimentally.

关键词： Preeclampsia Pathway Enrichment Analysis genetic algorithm optimization Gene Prioritization Weighted Adjacency Matrix

来源：评论

学校读者我要写书评

暂无评论

Time-Variant Gait Planning for Under-Actuated Biped Robot via optimization

Time-Variant Gait Planning for Under-Actuated Biped Robot vi...

引用

Chinese Intelligent Automation Conference (CIAC)

作者： OuYang, Xiaowei Pan, Gang Yu, Ling Zhejiang Univ Dept Control Sci & Engn New Ind Control Bldg 417 Hangzhou Zhejiang Peoples R China

ISBN: (纸本)9783642385247;9783642385230

The objective of this paper is to obtain time-variant optimal gaits for under-actuated biped robot via optimization. A time-variant gait planning method based on genetic algorithm is proposed in this paper. The reference trajectories of the actuated joints are defined as polynomial functions of time t. The trajectory of the under-actuated joint can be deduced from the rotational dynamics of the biped. To get the coefficients of the polynomial functions, optimization method based on genetic algorithm is adopted and minimal torque cost is chosen as the optimize criteria. Various low torque cost gaits can be obtained by considering different constraints during optimization. Simulation results illustrate the efficiency of our method.

关键词： Under-actuated biped robot Time-variant gait planning genetic algorithm optimization

来源：评论

学校读者我要写书评

暂无评论

A Novel Miniature Multi-Frequency Broadband Patch Antenna for WLAN Applications

A Novel Miniature Multi-Frequency Broadband Patch Antenna fo...

引用

8th IEEE International Conference on Industrial and Information Systems (ICIIS)

作者： Jayasinghe, Jeevani W. Uduwawala, Disala N. Univ Peradeniya Fac Engn Peradeniya Sri Lanka

ISBN: (纸本)9781479909087;9781479909094

Miniature antennas with multi frequency and broadband features have a high demand in the field of wireless communications. This paper proposes such a patch antenna for WLAN applications in UNII-1, UNII-2, UNII-2 extended and UNII-3 bands. The specialty of the antenna is its compact size with a foot print of only 8 mm x 4 mm. The patch with a shorting pin is etched on a substrate with a dielectric constant of 3.2 and a thickness of 0.762 mm and is suspended in air 5 mm above a ground plane. The patch geometry, feed point and shorting pin positions are optimized using genetic algorithms. The designed antenna displays a -10 dB fractional impedance bandwidth of 12.6 % and is suitable for handheld devices.

关键词： Broadband patch antenna Fractional bandwidth genetic algorithm optimization WLAN

来源：评论

学校读者我要写书评

暂无评论

Terrain-Adaptive Auxiliary Track Tensioning System for Tracked Vehicles

引用

JOURNAL OF COMPUTATIONAL AND NONLINEAR DYNAMICS 2013年第3期8卷 031013-031013页

作者： Matej, Jaroslav Tech Univ Zvolen Dept Forest & Mobile Technol Zvolen 96053 Slovakia

It is known that tension in the track of a tracked vehicle has a large effect on its driving properties. Simple track tensioning solutions, like track adjusting link assembly, use a one-road wheel motion to govern the motion of a track tensioning element. Thus the track tensioning force is a function of a terrain micro-profile. A logical improvement of this approach is to use all of the road wheels to govern the motion of the track tensioning element. This can be achieved by an auxiliary track tensioning system. This paper analyzes the conceptual track tensioning system governed by a terrain micro-profile. The motion of the track tensioning element is designed as a function of all of the road wheels' motions. A genetic algorithm method, implemented in Java language, is used to find the optimal parameters of the tensioning system and the results are verified via multibody dynamics simulation using the MSC. ADAMS/View system. The paper answers the question of whether the use of all of the road wheels' motions to govern the motion of the track tensioning element can be useful or not. The results indicate that the use of the auxiliary system can decrease the variance of the track tensioning force, in comparison with the track tensioning system without auxiliary tensioning. This means that the value of the track tensioning force is closer to its desired, predefined, and constant value during the whole simulation. The tracked vehicle model that is used is a simplified one and it is intended as a base for specific designs of track tensioning systems with auxiliary tensioning. The results suggest that the system can be used to improve the driving properties of tracked vehicles or robots.

关键词： track tensioning tracked vehicle tracked robot genetic algorithm optimization multibody dynamics simulation JGAP java genetic algorithm package MSC ADAMS/View automated dynamical analysis of mechanical system vehicle design track tensioning system tracked robot chassis

来源：评论

学校读者我要写书评

暂无评论

genetic algorithm-Based optimization Used in Rolling Schedule

引用

Journal of Iron and Steel Research International 2008年第2期15卷 18-22页

作者： YANG Jing-ming CHE Hai-jun DOU Fu-ping ZHOU Tao Institute of Electrical Engineering Yanshan University Qinhuangdao 006004 Hebei China

A genetic algorithm-based optimization was used for 1 370 mm tandem cold rolling schedule,in which the press rates were coded and *** superiority individual is reserved in every *** and comparison of optimized schedule with the existing schedule were *** is seen that the performance of the optimal rolling schedule is satisfactory and promising.

关键词： tandem cold rolling rolling schedule energy consumption genetic algorithm optimization

来源：评论

学校读者我要写书评

暂无评论

A Multi-Entity Field Approximation to determine the source location of multiple atmospheric contaminant releases

引用

ATMOSPHERIC ENVIRONMENT 2012年 62卷 593-604页

作者： Annunzio, Andrew J. Young, George S. Haupt, Sue Ellen Natl Ctr Atmospher Res Appl Res Lab Boulder CO 80307 USA Penn State Univ Dept Meteorol University Pk PA 16802 USA

In the event of an accidental or intentional contaminant release, it is imperative to locate the source of the contaminant for use in hazard prediction models. In some situations more than a single contaminant release will be present, which becomes a complicating factor when contaminants from these releases significantly overlap. Here we present a Lagrangian approach to determine the source locations of multiple contaminant releases. For this approach, we assume that the concentration field is approximated by a superposition of contaminant entities, where an entity is a discrete object;namely a puff for an instantaneous release and a plume for a continuous release. The state of each entity is inferred from surface observations of the contaminant, and extrapolation of each entity's state provides an estimate of the contaminant source locations. We call this method a Multi-Entity Field Approximation (MEFA) because together the entities' concentration fields sum to approximate the observed concentration field. In this work, we outline the MEFA process for both instantaneous and continuous contaminant releases using data from two FUSION Field Trial 2007 (FFT07) Trials where contaminant fields from multiple contaminant releases overlap close to the source location. Published by Elsevier Ltd.

关键词： Source term estimation Multi-Entity Field Approximation Entity Atmospheric transport and dispersion FUSION Field Trial 2007 genetic algorithm optimization

来源：评论

学校读者我要写书评

暂无评论

Grindstone4Spam: An optimization toolkit for boosting e-mail classification

引用

JOURNAL OF SYSTEMS AND SOFTWARE 2012年第12期85卷 2909-2920页

作者： Mendez, Jose R. Reboiro-Jato, M. Diaz, Fernando Diaz, Eduardo Fdez-Riverola, Fiorentino Univ Vigo Escuela Super Ingn Informat Orense Spain Univ Valladolid Escuela Univ Informat Segovia Spain Ultreia Comunicac SL Vigo Spain Univ Vigo Dept Comp Sci Vigo Spain Univ Valladolid Dept Comp Sci E-47002 Valladolid Spain

Resulting from the huge expansion of Internet usage, the problem of unsolicited commercial e-mail (UCE) has grown astronomically. Although a good number of successful content-based anti-spam filters are available, their current utilization in real scenarios is still a long way off. In this context, the SpamAssassin filter offers a rule-based framework that can be easily used as a powerful integration and deployment tool for the fast development of new anti-spam strategies. This paper presents Grindstone4Spam, a publicly available optimization toolkit for boosting SpamAssassin performance. Its applicability has been verified by comparing its results with those obtained by the default SpamAssassin software as well as four well-known anti-spam filtering techniques such as Naive Bayes, Flexible Bayes, Adaboost and Support Vector Machines in two different case studies. The performance of the proposed alternative clearly outperforms existing approaches working in a cost-sensitive scenario. (C) 2012 Elsevier Inc. All rights reserved.

关键词： SpamAssassin framework genetic algorithm optimization Naive Bayes Content-based techniques Spam detection

来源：评论

学校读者我要写书评

暂无评论

Design and optimization of a Parallel Guidance Device for Minimal Invasive Spinal Surgery

Design and Optimization of a Parallel Guidance Device for Mi...

引用

IEEE International Conference on Robotics and Biomimetics (ROBIO)

作者： Gao, Peng Hu, Ying Jin, Haiyang Zhang, Peng Zhang, Jianwei Chinese Acad Sci Shenzhen Inst Adv Technol Beijing 100864 Peoples R China

ISBN: (纸本)9781467321273;9781467321259

For most of the spinal surgeries, the pedicle screw insertion operation is a significant difficult procedure. To solve accurate position and keep the screw path in operation, a parallel guide device based on 3-RPS parallel mechanism is proposed in this paper. According to three degrees of freedom (Dofs), the inverse solution of the parallel mechanism, the workspace of parallel mechanism and institutional flexibility are calculated. And based on the finite element analysis, first six order natural frequency of parallel mechanism are analyzed. The integrated optimization method is used based on the kinematics and dynamics indexes. The frequency of the dynamic response of the different dimensions is gained by finite element software. The experimental design of Box-behken is used to get more sample data for fitting function by using least square method. Work spaces of institutions and frequency of the dynamic response is got. Kinematic indexes are the work spaces and institutional flexibility and the indexes of the dynamics is the first-order frequency response. Both as the objective function, to get optimal structural parameters size by genetic algorithm optimization based on kinematics and dynamics. By this approach, a good kinematics index and dynamic index of the parallel mechanism are obtained. Such a combination of both the formation of multi-objective optimization design can provide the basis of strong theoretical guidance for future engineering applications. Keywords: parallel mechanism, genetic algorithm optimization, multi-objective optimization

关键词： parallel mechanism genetic algorithm optimization multi-objective optimization

来源：评论

学校读者我要写书评

暂无评论

Linear Phase Second Order Recursive Digital Integrators and Differentiators

Linear Phase Second Order Recursive Digital Integrators and ...

引用

作者： Jain, M. Brno University of Technology

In this paper, design of linear phase second order recursive digital integrators and differentiators is discussed. New second order integrators have been designed by using genetic algorithm (GA) optimization method. Thereafter, by modifying the transfer function of these integrators appropriately, new digital differentiators have been obtained. The proposed digital integrators and differentiators accurately approximate the ideal ones and have linear phase response over almost entire Nyquist frequency range. The proposed operators also outperform the existing operators in terms of both magnitude and phase response.

关键词： Linear optimization genetic algorithm optimization digital integrator digital differentiator

来源：评论

学校读者我要写书评

暂无评论

Vector-dependent Functionally Pooled ARX Models for the Identification of Systems Under Multiple Operating Conditions

引用

IFAC Proceedings Volumes 2012年第16期45卷 310-315页

作者： Fotis P. Kopsaftopoulos Spilios D. Fassois Mechanical Systems & Automation (SMSA) Laboratory Dept. of Mechanical & Aeronautical Engr. University of Patras 26504 Patras Greece

The identification of stochastic systems operating under multiple conditions is addressed based on data records obtained under a sample of these conditions. The problem is important in many practical applications and is tackled within a recently introduced Functional Pooling framework. The study focuses on the case of operating conditions characterized by several parameters. Global Vector-dependent Functionally Pooled models of the ARX type are postulated, proper estimators based on the Least Squares and Maximum Likelihood principles are formulated, and their strong consistency and asymptotic normality are established. For model structure selection a genetic algorithm based procedure is formulated. The performance characteristics of the methods are assessed via a Monte Carlo study.

关键词： stochastic systems identification algorithms ARX models asymptotic analysis genetic algorithm optimization Monte Carlo simulations

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：