1,515 research outputs found

    Numerical methods for a quadratic matrix equation associated with an M-matrix

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    在科学与工程计算中常常遇到非线性矩阵方程,尤其是二次矩阵方程.本文研究 了一类特殊的二次矩阵方程X2−EX−F=0,其中E,F∈Rn×n,E是正对角矩阵, 而F是M-矩阵.这种类型的二次矩阵方程在Markov链的含噪Wiener-Hopf问题中 有着一定的应用.本文主要内容包括: 第一章,简单介绍了二次矩阵方程的相关理论与算法,并对相关的预备知识也作 了简要说明.主要内容包括非负矩阵,M-矩阵与一般矩阵理论的基本知识. 第二章,简单介绍了非对称代数Riccati方程的相关理论与数值算法. 第三章,在相关文献的基础上利用新的变换将这种特殊的二次矩阵方程转化为...Nonlinear matrix equation often arises in areas of science and engineering computation. This thesis, discusses numerical solution for a quadratic matrix equation associated with an M-matrix (M-QME) i.e. X2 − EX − F = 0, where E, F ∈ Rn×n, E is a diagonal matrix and F is an M-matrix. This type of quadratic matrix equation arises in the study of noisy Wiener-Hopf problems for the Mar...学位:理学博士院系专业:数学科学学院_计算数学学号:1902012015409

    Reviving the use of inhibitors of matrix metalloproteases in spinal cord injury:a case for specificity

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    At present, there are no restorative therapies in the clinic for spinal cord injury, with current treatments offering only palliative treatment options. The role of matrix metalloproteases is well established in spinal cord injury, however, translation into the clinical space was plagued by early designs of matrix metalloprotease inhibitors that lacked specificity and fears of musculoskeletal syndrome prevented their further development. Newer, much more specific matrix metalloprotease inhibitors have revived the possibility of using these inhibitors in the clinic since they are much more specific to their target matrix metalloproteases. Here, the evidence for use of matrix metalloproteases after spinal cord injury is reviewed and researchers are urged to overcome their old fears regarding matrix metalloprotease inhibition and possible side effects for the field to progress. Recently published work by us shows that inhibition of specific matrix metalloproteases after spinal cord injury holds promise since four key consequences of spinal cord injury could be alleviated by specific, next-generation matrix metalloprotease inhibitors. For example, specific inhibition of matrix metalloprotease-9 and matrix metalloprotease-12 within 24 hours after injury and for 3 days, alleviates spinal cord injury-induced edema, blood-spinal cord barrier breakdown, neuropathic pain and restores sensory and locomotor function. Attempts are now underway to translate this therapy into the clinic

    Rock Physics Characterization using Physical Methods on Powders

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    This study describes a detailed investigation of quantifying key micro-structural parameters of the unconsolidated granular media and their relationship with the grain shape factors calculated from micro-CT images. These parameters are combined with the contact based effective medium models to calculate the elastic properties of the constituent grains after utilising stress dependent ultrasonic velocities of the samples. Thus developed techniques produce good results for mono-mineral quartz sands and one of the poly-mineral rock powder

    THE CHALLENGE FOR DETERMINATION OF GLOBAL FRAUD LOSS – A QUALITATIVE STUDY

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    The high profile fraud incidents have captured the attention of people around the world about the real cost of accounting fraud. The business world is undeniably brimmed with scams and frauds that removed illegitimately billions of dollars. With the increasing number of high-profile scandals, the topic of fraud has attracted unprecedented attention in recent history. The direct losses from fraud and the impact of fraud have grown significantly and simply too costly which conveniently cannot be overlooked. Accordingly, the implications for the global determination of fraud loss has gained ground and has risen to prominence during recent years. The present study aims to examine why it is crucial to measure economic crimes or fraud and how the figure of global fraud loss can be quantifiable. Assessing and identifying the scale of loss from fraud is an important first step toward building a strategy for combating fraud. Equally important to developing a methodology for the accurate measurement of fraud loss globally. This paper explores how a better measurement is critical to a properly designed and strategic response to fraud. Better measurement of global fraud loss can provide a benchmark for exercising anti-fraud strategies, how the programs and activities can work to advantage. How to overcome data quality of global fraud loss and how to ensure the accuracy in exercising the collection methodologies. The methodology applied in this study is a qualitative case study method. The qualitative approach is aimed to determine, define, and investigate research problems. There is no denying the truth that there is no consistent and robust measure across global jurisdictions for determining fraud loss and error. The objective of measuring global fraud and error can be accomplished by implementing and legislating a global standard. The proposed changes are being envisaged as a guide to a global standard to measure the global loss from fraud

    Obstacle Avoidance Methods in UAVs

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    We contributed a method for avoiding obstacles using monocular vision as the only sensor in UAV (Unmaned Aerial vehicle). The vision based ROS (Robotic operating system) node detects the known obstacles in front of the UAV. Unknown obstacles can be taken care of by adding he information of all the obstacles seen in the scene to a map. The distance to obstacle in this research is calculated by just increasing size of the obstacle in front of the UAV. The image processing libraries were used from OpenCV to do thresholding, noise removal and contours detection. This research also tests and evaluate the path planning of UAV using MoveIt architecture, and evaluates the different results obtained.Hence we show the effectiveness of the monocular vision and size as a constraint algorithm in UAVs to detect and avoid frontal obstacles

    A systematic approach for monitoring and evaluating the construction project progress

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    A persistent problem in construction is to document changes which occur in the field and to prepare the as-built schedule. In current practice, deviations from planned performance can only be reported after significant time has elapsed and manual monitoring of the construction activities are costly and error prone. Availability of advanced portable computing, multimedia and wireless communication allows, even encourages fundamental changes in many jobsite processes. However a recent investigation indicated that there is a lack of systematic and automated evaluation and monitoring in construction projects. The aim of this study is to identifytechniques that can be used in the construction industry for monitoring and evaluating the physical progress, and also to establish how current computer technology can be utilised for monitoring the actual physical progress at the construction site. This study discusses the results of questionnaire survey conducted within Malaysian Construction Industry and suggests a prototype system, namely Digitalising Construction Monitoring (DCM). DCM prototype system integrates the information from construction drawings, digital images of construction site progress and planned schedule of work. Using emerging technologies and information system the DCM re-engineer the traditional practice for monitoring the project progress. This system can automatically interpret CAD drawings of buildings and extract data on its structural components and store in database. It can also extract the engineering information from digital images and when these two databases are simulated the percentage of progress can be calculated and viewed in Microsoft Project automatically. The application of DCM system for monitoring the project progress enables project management teams to better track and controls the productivity and quality of construction projects. The use of the DCM can help resident engineer, construction manager and site engineer in monitoring and evaluating project performance. This model will improve decision-making process and provides better mechanism for advanced project management

    A review of \u3cem\u3eAndroctonus finitimus\u3c/em\u3e (Pocock, 1897), with description of two new species from Pakistan and India (Scorpiones, Buthidae)

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    We describe Androctonus robustus sp. n. and A. cholistanus sp. n. from Pakistan and India and compare them with A. finitimus (Pocock, 1897), whose holotype we have studied. These three species are closely related and form a group that has hitherto been considered one species. They share coloration and are close to each other in geographic range. However, these three species can be reliably distinguished morphologically, primarily based on morphometry of male metasoma, which is widest in A. robustus sp. n. and narrowest in A. cholistanus sp. n
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