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Procedia - Social and Behavioral sciences 2012年 46卷 2297-2301页

作者： Ciobanu (defta) Costinela-Luminiţa Ciobanu (Iacob) Nicoleta-Magdalena Ph.D. student Faculty of Mathematics and Computer Science/Department of Computer Science University of Pitesti Targu din Vale Street No.1 Arges and Postcode 110040 Romania

Because more and more people are taking online courses, we need to understand the security issues of e-learning. The security aspect is even more important for the companies which use e-learning systems to deliver training courses to their employees. E-learning is a new method of learning which depends on the Internet in its execution, and is well known that Internet has become the venue for a new set of illegal activities, so e-learning environment is exposed to such threats. Information security can be obtained using methods such as cryptography, network protocols and others. In this paper we will discuss the typical threats of e-learning systems and we will see how we can address these issues. We will also discuss the security and privacy vulnerabilities of the most popular open-source e-learning systems, Moodle.

关键词： e-learning vulnerabilities education security Moodle

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Coalescent-based method for learning parameters of admixture events from large-scale genetic variation data 12

Coalescent-based method for learning parameters of admixture...

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2012 ACM Conference on Bioinformatics, Computational Biology and Biomedicine, BCB 2012

作者： Tsai, Ming-Chi Blelloch, Guy Ravi, R. Schwartz, Russell Joint CMU-Pitt Ph.D. Program in Computational Biology Carnegie Mellon University Pittsburgh PA United States Department of Computer Science Carnegie Mellon University Pittsburgh PA United States Tepper School of Business Carnegie Mellon University Pittsburgh PA United States Department of Biological Science Carnegie Mellon University Pittsburgh PA United States

ISBN: (纸本)9781450316705

detecting and quantifying the timing and the genetic contributions of parental populations to a hybrid population is an important but challenging problem in reconstructing evolutionary histories from genetic variation data. With the advent of high throughput genotyping technologies, new methods suitable for large-scale data are especially needed. Furthermore, existing methods typically assume the assignment of individuals into subpopulations is known, when that itself is a difficult problem often unresolved for real data. Here we propose a novel method that combines prior work for inferring non-reticulate population structures with an MCMC scheme for sampling over admixture scenarios to both identify population assignments and learn divergence times and admixture proportions for those populations using genomescale admixed genetic variation data. We validated our method using coalescent simulations and a collection of real bovine and human variation data. On simulated sequences, our methods show better accuracy and faster runtime than leading competitive methods in estimating admixture fractions and divergence times. Analysis on the real data further shows our methods to be effective at matching our best current knowledge about the relevant populations. Copyright © 2012 ACM.

关键词： Genes

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Synchronous Partial Replication – Case Study: Implementing e-Learning Platform in an Academic Environment

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Procedia - Social and Behavioral sciences 2012年 46卷 1522-1526页

作者： Ciobanu (Iacob) Nicoleta - Magdalena Ciobanu (defta) Costinela Luminiţa Ph.D. student Faculty of Mathematics and Computer Science/Department of Computer Science University of Pitesti Targu din Vale Street No.1 Arges and Postcode 110040 Romania Faculty of Touristic and Commercial Management “Dimitrie Cantemir” Christian University Unirii Blvd No 176 District 4 Bucharest Romania

Replication is the key factor in improving availability, fault-tolerance and accessibility of data in all types of distributed systems. Replicated data is stored at multiple sites so that it can be used even when some copies are not available due to site failures and databases are kept synchronized to maintain consistency. The scope of distributing these replicas is local data processing. This paper describes the importance of synchronous partial replication, implementation and query optimization steps using Oracle technology for an E-learning portal of a university with geographically distributed locations.

关键词： distributed databases replication methods strategies

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A Novel Ocean Sentinel Instrumentation Buoy for Wave Energy Testing

A Novel Ocean Sentinel Instrumentation Buoy for Wave Energy ...

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IEEE Power and Energy Society General Meeting

作者： Annette von Jouanne Ted Brekken Terry Lettenmaier Ean Amon Reo phillips School of Electrical Engineering and Computer Science at Oregon State University since 1995. Energy Systems at Oregon State University. University of Washington and M.S. degree from the University of Wisconsin Madison. Ph.D. degrees in electrical engineering from Oregon State University Corvallis in 2004 2007 and 2010 respectively.

ISBN: (纸本)9781467327275

This paper presents a novel Ocean Sentinel instrumentation buoy that the Northwest National Marine Renewable Energy Center (NNMREC) is developing with AXYS Technologies for the testing of wave energy converters (WECs). NNMREC is a department of Energy sponsored partnership between Oregon State University (OSU), the University of Washington (UW), and the National Renewable Energy Laboratory (NREL). The Ocean Sentinel instrumentation buoy is a surface buoy based on the 6-meter NOMAd (Navy Oceanographic Meteorological Automatic device) design. The Ocean Sentinel will provide power analysis and data acquisition, environmental monitoring, as well as an active converter interface to control power dissipation to an on-board electrical load. The WEC under test and the instrumentation buoy will be moored with approximately 100 meters separation, connected by a power and communication umbilical cable. The presentation of the paper will include the deployment and example testing of wave energy devices using the Ocean Sentinel instrumentation buoy.

关键词： Novel Ocean Instrumentation Wave energy cyhalothrin oceans dEPARTMENT OF ENERGY OPERATIONS power analysis Power dissipation Energy devices data Collection Methods deployment

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Towards energy efficiency in micro hovering air vehicles

Towards energy efficiency in micro hovering air vehicles

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2011 IEEE Aerospace Conference, AERO 2011

作者： Ratti, Jayant Vachtsevanos, George Ph.D. Robotics Program School of Electrical and Computer Engineering Georgia Institute of Technology Atlanta GA 30332 United States School of Electrical and Computer Engineering Georgia Institute of Technology Atlanta GA 30332 United States

ISBN: (纸本)9781424473502

Micro Aerial Vehicles (MAVs) have gained a significant amount of research lately, with a number of universities and industry sponsors paving the way with micro flying robots to perform Intelligence, Surveillance and Reconnaissance (ISR) Missions. However, much of the work done in VTOL/Hover-Capable MAVs till date has not shown performance improvement in flight endurance and payload capacities. In this paper we introduce and detail the Energy dynamics of a novel Quad-Wing MAV (QV) design and illustrate the improvement in-flight energy consumption, directed towards higher payload capacities and longer flight times. Additionally we show that independent wing control of the QV generates all 6 degrees of Freedom (doF) flight maneuvers. By the use of passive elastic elements, we can produce resonant flapping, generating lift and further improvements in energy savings. © 2011 IEEE.

关键词： Energy utilization

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Intelligent Pd-type fuzzy controller design for mobile satellite antenna tracking system with parameter variations effect

Intelligent PD-type fuzzy controller design for mobile satel...

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IEEE Symposium on Computational Intelligence in Control and Automation

作者： Lin, Jium-Ming Chang, Po-Kuang Dept. of Communication Engineering Chung-Hua University Hsin-Chu Taiwan Ph.D. Program in Engineering Science College of Engineering Chung-Hua University Hsin-Chu Taiwan

ISBN: (纸本)9781424499038

This research applied both the traditional and the fuzzy control methods for mobile satellite antenna tracking system design. Firstly, the antenna tracking and the stabilization loops were designed according to the traditional bandwidth and phase margin requirements. However, the performances would be degraded if the tacking loop gain is reduced due to parameter variations. On the other hand a Pd-type fuzzy controller was also applied for tracking loop design. It can be seen that the system performances obtained by the fuzzy controller were better for both low and high antenna tracking loop gains, and the tracking loop gain parameter variations effect can be reduced. © 2011 IEEE.

关键词： Fuzzy control

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MEMS technology on wafer-lever LEd packaging

MEMS technology on wafer-lever LED packaging

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2011 IEEE 13th Electronics Packaging Technology Conference, EPTC 2011

作者： Chang, Chunming Huang, Chenghan Lai, Tenghsien Tsou, Chingfu Hwang, Thong-Shing Chen, Chiming Department of Automatic Control Engineering Feng Chia University Taichung Taiwan Graduate Institute of Electrical and Communications Eng. Ph.D. Program Feng Chia University Taichung Taiwan Silicon Base Development Inc. Science Park Hsinchu Taiwan

ISBN: (纸本)9781457719837

This study demonstrated a newly type technology of a wafer level packaging method for light emitting diode (LEd) with aspheric lens and microlens array using microelectromechanical systems (MEMS) technology and transfer molding process. The novel packaging structure includes two components: the silicon-based packaging substrate which is formed with arrayed reflector depression and through-hole interconnects by bulk micromachining and the optical encapsulation with lens configuration that formed by transfer molding in wafer level. By this pattern transfer process, the precise alignment between lens configuration and the reflector of silicon substrate can be achieved and batch process can be realized to reduce the costs. Beside, the packaging element can be used more applications. In the study, the pattern transfer of various lens profiles was also accomplished successfully by using silicone gel as lens mold. The brightness of the packaging elements with single aspheric lens profile and high fill factor microlens array can be increased by 26% and 16%, respectively, in comparison to the case of optical encapsulation with smooth curved surface. Furthermore, the light radiation uniformity was improved effectively through 100% fill factor microlens array. Therefore, the structure can satisfy the requirements of wafer level LEd packaging and improve the heat dissipation and light extraction efficiency. © 2011 IEEE.

关键词： Batch data processing

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The Replication Technology in E-learning Systems

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Procedia - Social and Behavioral sciences 2011年 28卷 231-235页

作者： Iacob (Ciobanu) Nicoleta – Magdalena Ph.D. student Faculty of Mathematics - Computer Science /Department of Computer Science University of Pitesti Str. Targu din Vale nr.1 Arges and Postcode 110040 Romania

The distributed systems are attractive for the users with various, interactive activities that require large processing capabilities, resource sharing and high availability. This paper presents the advantages of e-Learning education and focus on the importance of data replication in the design of a distributed database system that an e-learning portal uses. In addition, we analyze the available methods and strategies of data replication depending on needs, for improving performance and increasing data availability. The purpose of this paper is to present the advantages of using data replication technology in e-learning systems by universities with geographically distributed locations.

关键词： e-Learning distributed databases fragmentation replication allocation methods strategies

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distributed Queries in the E-learning Environment

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Procedia - Social and Behavioral sciences 2011年 28卷 241-245页

This paper presents the advantages of e-Learning education and focus on query processing in distributed databases. For this, we present the factors that influence distributed query optimization and examine the optimization strategies of query execution. The goal of this paper is to present strategies of optimizing query execution in e-learning systems used mainly by universities with geographically distributed locations, in order to obtain a system response time as low as possible and to minimize the total cost of implementation.

关键词： e-Learning distributed databases queries factors strategies

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Towards low-power, low-profile avionics architecture and control for micro aerial vehicles

Towards low-power, low-profile avionics architecture and con...

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2011 IEEE Aerospace Conference, AERO 2011

作者： Ratti, Jayant Moon, Jung-Ho Vachtsevanos, George Ph.D. Robotics Program Electrical and Computer Engg. Dept. Georgia Institute of Technology Atlanta GA 30332 United States Kangnung National Univ. Korea Republic of Georgia Institute of Technology Atlanta GA 30332 United States Electrical and Computer Engg. Dept. Georgia Institute of Technology Atlanta GA 30332 United States

ISBN: (纸本)9781424473502

The conventional Mini and Large scale UAV systems span anywhere from approximately 12 inches to 12 feet;endowing them with larger propulsion systems, batteries/fuel-tanks, which in turn provide ample footprint and power reserves for on-board avionics and wireless telemetry. The limitations thus imposed become apparent when shifting to Micro Aerial Vehicles (MAVs) and trying to equip them with equal or near-equal processing, sensing and communication capabilities, as their larger scale cousins. The conventional MAV as outlined by dARPA is a vehicle that can have a maximum dimension of 6 inches and weighs no more than 100 grams. Under these tight constraints, the footprint, weight and power reserves available to on-board avionics is drastically reduced. The paper presents the advent of a new line of Micro Architecture and Control (MARC) avionics systems with very low-power, multi-sensor, multi-processor avionics interconnect architecture designed specifically with the power and payload constraints of MAVs in mind. The results and a Real Time Operating System (RTOS) based Hardware in the Loop Simulation (HILS), flight control is discussed towards the end. © 2011 IEEE.

关键词： Flight simulators

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