检索结果-内蒙古大学图书馆

Comparison of threshold selection methods for microarray gene co-expression matrices

BMC Research Notes 2009年第1期2卷 1-6页

作者： Borate, Bhavesh Chesler, Elissa Langston, Michael Saxton, Arnold Voy, Brynn Genome Science and Technology Program University of Tennessee Knoxville TN United States Department of Electrical Engineering and Computer Science University of Tennessee Knoxville TN United States Oak Ridge National Laboratory Systems Genetics Group Biosciences Division Oak Ridge TN United States Department of Animal Science University of Tennessee Knoxville TN United States

Background. Network and clustering analyses of microarray co-expression correlation data often require application of a threshold to discard small correlations, thus reducing computational demands and decreasing the number of uninformative correlations. This study investigated threshold selection in the context of combinatorial network analysis of transcriptome data. Findings. Six conceptually diverse methods - based on number of maximal cliques, correlation of control spots with expressed genes, top 1% of correlations, spectral graph clustering, Bonferroni correction of p-values, and statistical power - were used to estimate a correlation threshold for three time-series microarray datasets. The validity of thresholds was tested by comparison to thresholds derived from Gene Ontology information. Stability and reliability of the best methods were evaluated with block bootstrapping. Two threshold methods, number of maximal cliques and spectral graph, used information in the correlation matrix structure and performed well in terms of stability. Comparison to Gene Ontology found thresholds from number of maximal cliques extracted from a co-expression matrix were the most biologically valid. Approaches to improve both methods were suggested. Conclusion. Threshold selection approaches based on network structure of gene relationships gave thresholds with greater relevance to curated biological relationships than approaches based on statistical pair-wise relationships. © 2009 Saxton et al;licensee BioMed Central Ltd.

关键词： Spectral Cluster Maximal Clique Threshold Estimate Biological Relationship Spectral Graph

来源：评论

学校读者我要写书评

暂无评论

Gait recognition system tailored for Arab costume of the Gulf region

Gait recognition system tailored for Arab costume of the Gul...

引用

IEEE International Symposium on Signal Processing and Information Technology (ISSPIT)

作者： Tamer Shanableh Khaled Assaleh Layla Al - Hajjaj AbdulWahab Kabani Department of computer science and Engineering American University of Sharjah UAE Department of Electrical Engineering American University of Sharjah UAE Computer Science program American university of Sharjah UAE

Existing work on gait recognition is focused on casual (western) customs hence not suitable for the gulf region where long gowns are used for both men and women. This paper proposes a gait recognition solution that is suitable for both gulf customs and casual customs. The solution is based on computing an adaptive image prediction between consecutive images. The resultant predictions are then accumulated into one image and transformed using either discrete cosine transformation (DCT) or Radon transformation. The feature vectors of the gait are computed from such transformed images. Feature modeling based on polynomial networks follows. The proposed solution is tested on a dataset with around 100 participants with mixed genders and mixed customs. The proposed system yields an impressive classification rates approaching 100% accuracy.

关键词： Least squares approximation Electrocardiography Computational complexity Noise cancellation Computational modeling Adaptive filters Steady-state Educational institutions Signal to noise ratio Vectors

来源：评论

学校读者我要写书评

暂无评论

Sensors: DNA Sensing Using Nanocrystalline Surface‐Enhanced Al2O3Nanopore Sensors (Adv. Funct. Mater. 8/2010)

引用

Advanced Functional Materials 2010年第8期20卷

作者： Bala Murali Venkatesan Amish B. Shah Jian‐Min Zuo Rashid Bashir Department of Electrical and Computer Engineering University of Illinois at Urbana Champaign Urbana IL 61801 (USA) Micro and Nanotechnology Laboratory University of Illinois at Urbana Champaign Urbana IL 61801 (USA) Frederick Seitz Materials Research Laboratory University of Illinois at Urbana Champaign Urbana IL 61801 (USA) Department of Materials Science and Engineering University of Illinois at Urbana Champaign Urbana IL 61801 (USA) Department of Bioengineering University of Illinois at Urbana Champaign Urbana IL 61801 (USA)

来源：评论

学校读者我要写书评

暂无评论

Quantitative shear wave imaging of cell culture gels

Quantitative shear wave imaging of cell culture gels

引用

2009 IEEE International Ultrasonics Symposium, IUS 2009

作者： Orescanin, Marko Toohey, Kathleen S. Insana, Michael F. Department of Electrical and Computer Engineering University of Illinois at Urbana-Champaign Urbana IL 61801 United States Department of Bioengineering University of Illinois at Urbana-Champaign Urbana IL 61801 United States Beckman Institute for Advanced Science and Technology University of Illinois at Urbana-Champaign Urbana IL 61801 United States

ISBN: (纸本)9781424443895

An ultrasonic shear wave imaging technique is being developed for estimating viscoelastic properties of hydrogels. A needle placed in the medium is vibrated along its axis to generate harmonic shear waves. Doppler pulses synchronously track shear wave propagation to estimate the local speed. Fitting shear-wave speed estimates to the dispersion relation obtained from two rheological models, we estimate the complex shear modulus, viz., elastic and viscous components. The dispersion equation estimated using the standard solid-body (Zener) model is compared to that from the Kelvin-Voigt model to explore the frequency landscape of hydrogel viscoelasticity within the 50-450 Hz shear wave bandwidth. We found both models give comparable estimates that each agree with independent rheometer measurements obtained at lower strain rates, as might be expected form these highly elastic gels. ©2009 IEEE.

关键词： Gels

来源：评论

学校读者我要写书评

暂无评论

Complex shear modulus of thermally-damaged liver

Complex shear modulus of thermally-damaged liver

引用

2009 IEEE International Ultrasonics Symposium, IUS 2009

作者： Orescanin, Marko Qayyum, Muqeem A. Toohey, Kathleen S. Insana, Michael F. Department of Electrical and Computer Engineering University of Illinois at Urbana-Champaign Urbana IL 61801 United States Department of Bioengineering University of Illinois at Urbana-Champaign Urbana IL 61801 United States Beckman Institute for Advanced Science and Technology University of Illinois at Urbana-Champaign Urbana IL 61801 United States

ISBN: (纸本)9781424443895

The complex shear modulus of fresh and thermally damaged porcine liver has been measured, in vitro, using an ultrasonic shear wave imaging technique. Measurements were compared to two constitutive models, Kelvin-Voigt and Zener, to estimate the complex modulus of liver for shear wave frequencies between 50 and 300 Hz. An axially vibrated needle placed in the liver excites harmonic shear waves that are imaged using a pulsed Doppler technique. Liver heated to 47°C for 90 min was found to have little measurable cellular damage, and yet the elastic shear modulus increased by a factor of two and the viscous shear modulus increased by a factor of three in this frequency range. These observations imply that elastic properties, especially the viscous shear modulus, may be a sensitive indicator of thermal damage. Also, within the testing bandwidth for shear waves, the Zener model represented the data better than the Kelvin-Voigt model. ©2009 IEEE.

关键词： Shear waves

来源：评论

学校读者我要写书评

暂无评论

Registration of finger vein image using skin surface information for authentication

Registration of finger vein image using skin surface informa...

引用

Image Processing: Machine Vision Applications II

作者： Noh, SeungWoo Kong, Hyoun-Joong Park, SangYun Kim, JiMan Lee, Seung-Rae Kim, Taejeong Kim, Hee Chan Interdisciplinary Program Bioengineering Major Graduate School Seoul National University Seoul Korea Republic of Interdisciplinary Program Biomedical Engineering Major Graduate School Seoul National University Seoul Korea Republic of Institute of Medical and Biological Engineering Medical Research Center Seoul National University Seoul Korea Republic of Department of Electrical Engineering and Computer Sciences Seoul National University Seoul Korea Republic of Department of Biomedical Engineering College of Medicine Seoul National University Seoul Korea Republic of

ISBN: (纸本)9780819475015

The finger vein image acquired with an acquisition system should be properly aligned to proceed with comparing algorithm. However it is not easy to find control the points since the images are naturally blurred with an inherent scattering property. To overcome this problem, we propose a novel finger vein registration method utilizing skin surface information (i.e. wrinkles and outlines). We assumed that finger crooking was insignificant. Images were sampled with intended translation and rotation. Each time, two images were acquired successively by switching the light source;one with infrared light and the other with white light. Degree of rotation and translation of sampled image were calculated using outline features in the white light image and then the infrared image was transformed according to the calculated data. To validate our method, correlation values were computed between identical subjects and different subjects. High correlation values were shown between identical subjects whereas low values were shown between different subjects. © 2009 SPIE.

关键词： Authentication

来源：评论

学校读者我要写书评

暂无评论

A parallel spiking neural network simulator

A parallel spiking neural network simulator

引用

IEEE International Conference on Field-programmable Technology (FPT)

作者： Kit Cheung Simon R. Schultz Philip H.W. Leong Department of Computer Science and Engineering Chinese University of Hong Kong Hong Kong China Department of Bioengineering Imperial College London UK Department of Electrical and Information Engineering University of Sydney Australia

An FPGA-based systolic architecture for the high speed simulation of spiking neural networks is presented. The design is an implementation of Izhikevich's neuron model and employs optimizations for the typical case where neuron activity is low. Since execution time required is related to the activity level, performance of the design can be improved by an order of magnitude.

关键词： Neural networks Neurons Computational modeling Biological neural networks Biological system modeling Brain modeling computer simulation Large-scale systems Field programmable gate arrays Frequency

来源：评论

学校读者我要写书评

暂无评论

Enhanced glucose sensor linearity using poly(vinyl alcohol) hydrogels

引用

Journal of Diabetes science and Technology 2009年第4期3卷 863-874页

作者： Vaddiraju, SanthiSagar Singh, Hardeep Burgess, Diane J. Jain, Faquir C. Papadimitrakopoulos, Fotios Polymer Program Institute of Material Science University of Connecticut Storrs CT 06269 United States Department of Pharmaceutical Sciences University of Connecticut Storrs CT United States Nanomaterials Optoelectronics Laboratory Electrical and Computer Engineering University of Connecticut Storrs CT United States Department of Chemistry University of Connecticut Storrs CT United States

Background: High linearities, sensitivities, and low oxygen dependence constitute prime requisites for electrochemical glucose sensors. However, for implantable sensors the need to control tissue inflammation requires the use of outer membranes that permit inward analyte diffusion while continuously releasing anti-inflammatory drugs and other tissue response-modifying (TRM) agents. We have shown previously that while outer membranes based on layer-by-layer (LBL) assembly enhance linearity, poly(vinyl alcohol)(PVA) hydrogels loaded with TRM-containing microspheres enable a significant reduction in tissue inflammation. This article discusses the amperometric performance of glucose sensors coated with stacked LBL/PVA hydrogel outer membranes. Methods: Sensors were fabricated by immobilizing glucose oxidase enzyme on a 50-μm platinum wire followed by deposition of stacked LBL/PVA hydrogel outer membranes. The sensor response to various glucose concentrations was determined by applying 0.7 V vs an Ag/AgCl reference electrode in phosphate-buffered saline (37°C). Michaelis-Menten analysis was performed to quantify sensor performance in terms of linearity (Km,gluapp) and oxygen dependence (Km,O2app/[Glucose]). Results: When overlaid onto LBL-assembled outer membranes, PVA hydrogels improved sensor linearity by 60% from 10 to 16 m M of glucose and resulted in a twofold decrease in oxygen dependence. Conclusions: Enhancement in the performance of a PVA-coated sensor is attributed to the oxygen-storing capability of PVA hydrogel due to the formation of hydrophobic domains during its freezing and thawing employed to physical cross-link the PVA. Such membranes with the capability to release TRMs continuously while storing oxygen constitute a major improvement over current outer membrane technologies. © Diabetes Technology Society.

关键词： Apparent Michaelis-Menten constants Biosensor Freeze-thaw cycle Layer-by-layer assembly Linearity Outer membranes Oxygen content Oxygen dependence of biosensors PVA hydrogels

来源：评论

学校读者我要写书评

暂无评论

Achievable Capacity of a Spectrum Sharing System over Hyper Fading Channels

Achievable Capacity of a Spectrum Sharing System over Hyper ...

引用

GLOBECOM 2009 - 2009 IEEE Global Telecommunications Conference

作者： Sabit Ekin Ferkan Yilmaz Hasari Celebi Khalid A. Qaraqe Mohamed-Slim Alouini Erchin Serpedin Department of Electrical and Computer Engineering Texas A and M University Qatar Doha Qatar Electrical Engineering Program King Abdullah University for Science and Technology Thuwal Saudi Arabia

Cognitive radio with spectrum sharing feature is a promising technique to address the spectrum under-utilization problem in dynamically changing environments. In this paper, achievable capacity gain of spectrum sharing systems over dynamic fading environments is studied. For the analysis, a theoretical fading model called hyper fading model that is suitable to the dynamic nature of cognitive radio channel is proposed. Closed-form expression of probability density function (PDF) and cumulative density function (CDF) of the signal-to-noise ratio (SNR) for secondary users in spectrum sharing systems are derived. In addition, the capacity gains achievable with spectrum sharing systems in high and low power regions are obtained. Numerical simulations are performed to study the effects of different fading figures, average powers, interference temperature, and number of secondary users on the achievable capacity.

关键词： Fading Power system modeling Rayleigh channels Temperature Cognitive radio Interference constraints Random variables computer science education Educational programs Systems engineering education

来源：评论

学校读者我要写书评

暂无评论

Determination of Thermal Parameters of Nanostructures Exhibiting One-Dimensional Heat Flow Through a Thermal Transient Method

引用

MRS Online Proceedings Library 2009年第1期1172卷 54-59页

作者： Arriagada, Anton Yu, Edward T. Bandaru, Prabhakar R. Deparment of Electrical and Computer Engineering University of California at San Diego La Jolla USA Materials Science Program Mechanical Engineering Department University of California at San Diego La Jolla USA

We present an improved methodology for a thermal transient method enabling simultaneous measurement of thermal conductivity and specific heat of nanoscale structures with one-dimensional heat flow. The temporal response of a sample to finite duration heat pulse inputs for both short (1 ns) and long (5μs) pulses is analyzed and exploited to deduce the thermal properties. Excellent agreement has been obtained between the recovered physical parameters and computational simulations.

关键词： thermal conductivity nanoscale simulation

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：