检索结果-内蒙古大学图书馆

International Journal of Multimedia and Ubiquitous engineering 2013年第5期8卷 41-50页

作者： Hassan, Walid A. Jo, Han-Shin Shamsan, Zaid A. Rahman, Tharek A. Wireless Communication Center Universiti Teknologi Malaysia Malaysia Dept. of Electronics and Control Engineering Hanbat National University Korea Republic of Communications and Computer Department Taiz University Taiz Yemen Al-Imam Mohammad ibn Saud Islamic University Riyadh Saudi Arabia

The 470-862 MHz band has recently incurred two major spectrum reallocations: the introduction of digital broadcasting (DB) and the allocation of the 790-862 MHz sub-band as a co-primary base for mobile services. While some countries have accomplished full digital switchover (DSO) and implemented DB as their platform for TV broadcasting, others are still in the trial phase. Until 2015, this sub-band will be usable for either broadcasting or mobile service;lack of coordination between neighboring countries could thus result in co-channel interference. Using a Monte Carlo method, we evaluated the minimum separation distance (MSD) and carrier frequency separation necessary to achieve compatibility. Digital video broadcasting-terrestrial (DVB-T) systems can be protected from international mobile telecommunications-advanced (IMT-A) systems using a carrier frequency separation of 17 MHz. Although IMT-A systems are not protected from DVB-T in this sharing scenario, coexistence between adjacent channels is ensured without recourse to interference mitigation by use of a carrier frequency of at least 15 MHz. © 2013 SERSC.

关键词： Monte Carlo methods

来源：评论

学校读者我要写书评

暂无评论

Online control message aggregation in chain networks

Online control message aggregation in chain networks

引用

13th International Symposium on Algorithms and Data Structures, WADS 2013

作者： Bienkowski, Marcin Byrka, Jaroslaw Chrobak, Marek Jez, Lukasz Sgall, Jiří Stachowiak, Grzegorz Institute of Computer Science University of Wroclaw Poland Department of Computer Science University of California Riverside CA United States Dept. of Computer Control and Management Engineering Sapienza University of Rome Italy Computer Science Institute Faculty of Mathematics and Physics Charles University Czech Republic

ISBN: (纸本)9783642401039

In the control Message Aggregation (CMA) problem, control packets are generated over time at the nodes of a tree T and need to be transmitted to the root of T. To optimize the overall cost, these transmissions can be delayed and different packets can be aggregated, that is a single transmission can include all packets from a subtree rooted at the root of T. The cost of this transmission is then equal to the total edge length of this subtree, independently of the number of packets that are sent. A sequence of transmissions that transmits all packets is called a schedule. The objective is to compute a schedule with minimum cost, where the cost of a schedule is the sum of all the transmission costs and delay costs of all packets. The problem is known to be -hard, even for trees of dept. 2. In the online scenario, it is an open problem whether a constant-competitive algorithm exists. We address the special case of the problem when T is a chain network. For the online case, we present a 5-competitive algorithm and give a lower bound of 2 + φ ≈ 3.618, improving the previous bounds of 8 and 2, respectively. Furthermore, for the offline version, we give a polynomial-time algorithm that computes the optimum solution. © 2013 Springer-Verlag.

关键词： Costs

来源：评论

学校读者我要写书评

暂无评论

Multi-view people detection on arbitrary ground in real-time

Multi-view people detection on arbitrary ground in real-time

引用

8th International Conference on computer Vision Theory and Applications, VISAPP 2013

作者： Kiss, Ákos Szirányi, Tamás Distributed Events Analysis Research Group Computer and Automation Research Institute Hungarian Academy of Sciences Budapest Hungary Dept. of Control Engineering and Information Technology Budapest University of Technology and Economics Budapest Hungary

ISBN: (纸本)9789898565471

We show a method to detect accurate 3D position of people from multiple views, regardless of the geometry of the ground. In our new method we search for intersections of 3D primitives (cones) to find positions of feet. The cones are computed by back-projecting ellipses covering feet in input images. Instead of computing complex intersection body, we use approximation to speed up intersection computing. We found that feet positions are determined accurately, and the height map of the ground can be reconstructed with small error. We compared our method to other multiview-detectors - using somewhat different test methodology -, and achieved comparable results, with the benefit of handling arbitrary ground. We also present accurately reconstructed height map of non-planar ground. Our algorithm is fast and most of steps are parallelizable, making it possibly available for smart camera systems.

关键词： computer vision

来源：评论

学校读者我要写书评

暂无评论

Hardware Implementation on FPGA of Two Modulation Techniques for Three Phase Inverters

Hardware Implementation on FPGA of Two Modulation Techniques...

引用

IEEE International Conference on Intelligent computer Communication and Processing

作者： B. Alecsa A. Onea Dept. of Automatic Control and Computer Engineering Technical University of Iasi

ISBN: (纸本)9781479914920

This paper presents two modern modulation techniques applied to three phase inverters from a hardware implementation point of view. The considered techniques are the sinusoidal pulse width modulation with zero sequence injection and the space vector modulation. Both these techniques conduct to the same result regarding supply voltage usage efficiency and harmonic content of the resulted signals. The implementation was developed in Matlab-Simulink, using the System Generator software, and validated through simulation. Both the modulation algorithms were implemented in hardware on a low cost FPGA, and the resulted designs are compared for resource usage efficiency, obtained speed and easiness of integration within a complex AC drive control system.

关键词： Sinusoidal PWM ZSS SVM FPGA System Generator

来源：评论

学校读者我要写书评

暂无评论

Improvements in BondLib, the Modelica Bond Graph Library

Improvements in BondLib, the Modelica Bond Graph Library

引用

EUROSIM Congress on Modelling and Simulation (EUROSIM)

作者： Alberto de la Calle François E. Cellier Luis J. Yebra Sebastián Dormido Automatic Control Group CIEMAT-Plataforma Solar de Almería Tabernas Spain ETH Zürich Institute of Computational Science Zürich Switzerland Dept. of Computer Science and Automatic Control UNED Madrid Spain

Bond graphs are a natural method for representing power flows in physical systems and they represent the most basic graphical paradigm that is still fully object-oriented. This paper describes a new version of BondLib, the Modelica bond graph library. The library was created for Modelica with graphical Dymola support, and its object-oriented design allows the wrapping of bond graph models offering a user-friendly environment for modeling physical system in multiple energy domains. The new improvements try to reduce the deployment and training cost for end-users by making the error diagnostics easier.

关键词： Mathematical model Connectors Object oriented modeling Libraries Equations Junctions Computational modeling

来源：评论

学校读者我要写书评

暂无评论

Peer-assessment and grading of open answers in a web-based e-learning setting

Peer-assessment and grading of open answers in a web-based e...

引用

International Conference on Information Technology Based Higher Education and Training, ITHET

作者： Andrea Sterbini Marco Temperini Dept. of Computer Science Sapienza University of Roma Roma Italy Dept. of Computer Control and Management Engineering Sapienza University of Roma Roma Italy

Grading the answers given to open ended questions (and questionnaires) is a rather heavy task for teachers and lecturers. Several techniques have been used to automatically analyze the student's essays, but natural language processing is not yet ready to completely solve the task. We propose a solution, for the automated support to answers grading, where the students' peer assessment is checked against the teacher's marking, while such teacher's marking has to be performed on only a subset of the answers (so relieving the teacher by at least a part of the marking task). Our aim is twofold: 1) to make grading more effective by propagating the teacher's assessments through the network of peer assessments (so to maintain a progressively improved evaluations of the peer assessments precision and make them more likely to be used for final grading); 2) to suggest iteratively the teacher with the next most informative essays to grade (respect to the network, that is one of the answers whose teacher's mark will inject most information into the network and make the system better able to deduce the rest of the grades. To this aim we have used a very simple Bayesian model of peers and peer assessment, and we have built a web-based system to support the teacher. We show the present state of the model and its implementation. Moreover, we show, through a simulation protocol, how the system can support the teacher, obtaining a reasonably good correction with just a subset of the whole grades.

关键词： Bayes methods Electronic learning Knowledge engineering Probability distribution Proposals Data mining Probabilistic logic

来源：评论

学校读者我要写书评

暂无评论

OpenAnswer, a framework to support teacher's management of open answers through peer assessment

OpenAnswer, a framework to support teacher's management of o...

引用

Frontiers in Education (FIE) Conference

作者： Andrea Sterbini Marco Temperini Dept. of Computer Science Sapienza University of Roma Roma Italy Dept. of Computer Control and Management Engineering Sapienza University of Roma Roma Italy

Open-ended questions are an important means to support analysis and assessment of students; they can be of extraordinary effectiveness for the assessment of higher cognitive levels of the Bloom's Taxonomy. On the other hand, assessing open answers (textual, freely shaped, answers to a question) is a hard task. In this paper we describe an approach to open answers evaluation based on the use of peer-assessment: in a social-collaborative e-learning setting implemented by the OpenAnswer web system, the students answer questions and rate others' (and may be own) answers, while the teacher marks a subset of the answers so to allow the system inferring the rest of the marks. The aim of our system is to ease the teacher's marking burden and allow for a more extensive use of open ended questionnaires in her/his teaching activity.

关键词： Bayes methods Probability distribution Computational modeling Educational institutions Data mining Taxonomy Electronic learning

来源：评论

学校读者我要写书评

暂无评论

A Droop controller is intrinsically a Phase-Locked Loop

A Droop Controller is intrinsically a Phase-Locked Loop

引用

Annual Conference of the IEEE Industrial Electronics Society

作者： Qing-Chang Zhong Dushan Boroyevich Dept. of Automatic Control and Systems Engineering The University of Sheffield Center for Power Electronics Systems Virginia Polytechnic Institute and State University

ISBN: (纸本)9781479902255

This paper demonstrates that a droop controller, which is fundamental to the operation of power systems and now the parallel operation of inverters, is intrinsically the same as a phase-locked loop (PLL), which is widely adopted in modern electrical engineering. This bridges the gap between the two communities working on droop control and PLLs. As a result, droop controllers and PLLs can be improved and further developed via adopting the advancements in the other community. This also offers insightful understanding to power systems that have inverters and generators mixed together and leads to significant technological breakthrough for the grid connection of renewable energy. For example, there is no longer a need for grid-connected inverters to have a phase-locked loop and a droop controller at the same time.

关键词： Phase locked loops Inverters Impedance Reactive power Frequency control Voltage control

来源：评论

学校读者我要写书评

暂无评论

Study of Impact of Wind Power Penetration on Frequency Stabilization in Multi-area Power System

Study of Impact of Wind Power Penetration on Frequency Stabi...

引用

International Symposium on Advanced Topics in Electrical engineering

作者： H. D. Mathur L. B. F. Leite H. Siguerdidjane Y. K. Bhateshvar Automatic Control Department Supélec Gif-sur-Yvette France Dept. of Electrical and Electronics Engineering BITS Pilani India

ISBN: (纸本)9781467359795

This paper presents a comprehensive study on the wind power impact with increasing penetration on frequency stabilization in restructured power system scenario. The focus of the study is on faster and smoother settlement of frequency and tie-line power. A large penetration of wind power generation causes imbalance in power system because of its intermittent output. The wind power generation system does not provide inertia and isolates from the grid during disturbances but this possibility becomes milder if wind power generators also contribute to system inertia. The proposed control scheme with fuzzy logic uses frequency deviations to provide fast active power support, which blocks the fall in frequency and tie-line power during transient conditions. The simulation studies have been conducted in a two-area interconnected power system in restructured environment.

关键词： Two Area Power System Wind power Deregulated Environment Fuzzy Logic controller

来源：评论

学校读者我要写书评

暂无评论

Implementation of a telemedicine system for optimal on site medical response in case of disasters and for emergency situations management

Implementation of a telemedicine system for optimal on site ...

引用

E-Health and Bioengineering Conference (EHB)

作者： Ciprian Lupu Vasile Olaru Dorel Bivolan Andreea Udrea Dept. of Automatic Control and Systems' Engineering University Politehnica of Bucharest Bucharest Romania Research Dept. IAROM S.A. Bucharest Romania Research Dept. ELPROF S.A. Bucharest Romania

This paper presents a telemedicine support system developed by implementing an integrated disaster management protocol, and providing specialized expertise in local/remote affected regions (affected civilians, soldiers, rescuers, explorers, people in remote areas, etc.). The system has a modular structure consisting in: a containerized management system (regional / local), a mobile monitoring-rescue system including an individual acquisition and monitoring system and a communication handheld/portable monitoring stretcher and an integrated communication module and other software facilities.

关键词： Global Positioning System Servers Monitoring Biomedical monitoring Communities Databases Biology

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：