• Journal of Positioning, Navigation, and Timing
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• 제10권4호
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• pp.387-393
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• 2021

This paper proposes a system to synchronize the time of computers over an unmanned aerial vehicle (UAV) network. With the proposed system, the UAVs can perform missions that require precise relative time. Also, data collected by UAVs can be fused precisely with synchronized time. In the system, to synchronize the time of all computers over the UAV network, two-step synchronization is performed. In the first step, the mission computers of the UAVs are synchronized through the server of the system. After the first step, the mission computers measure time offset between the time of the mission computers and the flight computers. The offset values are delivered to the server. In the second step, virtual time is determined by the server from the collected time offset. The measured offset is compensated by moving the synchronized time of mission computers to the reasonable virtual time. Since only the time of mission computers are controlled, any flight computers that use micro air vehicle link (MAVLink) protocol can be synchronized in the proposed system.

• 환경위생공학
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• 제14권1호
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• pp.1-10
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• 1999

This study was carried out to improve management of wasted home appliances and computers. The generation of wasted home appliances and computers in korea was estimated. Disassembling wasted home appliances and computers according to disassembly procedure, investigate fittings weight and disassembly time. To evaluate hazardous contaminants from televisions and computers, measure heavy metals by leaching test.

• 한국실내디자인학회논문집
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• 제28호
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• pp.158-166
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• 2001

e-revolution makes a lot of changes in the methodology all over the world. That is, the theory of real time showing helps people to access audio and visual wherever and whenever they are. In the pst computers were considered as only tools which could make us work easily. However, the meaning of computer is changing with e-revolution nowadays. Computers are not just computers as they were; they have done a lot of things which we thought impossible and they will do in the future as well. This new wave encourages people who are teaching the design to use computers whatever they do. For example, instead of using pencil and a drafting board, most people in the design field work with monitors, mouse and plotter. Therefore, most people who are in the design field need to have the ability of computer skills. They have to use computers not only in their class but also in their office. However, if we use computers for visual presenting in the class, it will not be enough to catch the e-revolution. That is, we should work with computers in the creative and conceptual design such as the using of the design information and the applying digital techniques in the early stage of the work. The purpose of this study is to show how to work with computers in the spacial design process especially th using of the DIS(Design Information System) and the applying digital techniques in the early stage of the work.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1633-1637
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• 2003

Existing input devices for desktop computers are not suitable for wearable computers because they are neither easy to carry nor convenient to use in a mobile working environment. Different input devices for wearable computers must be developed. In this paper, a wireless glove-based input device for wearable computers is proposed. The proposed input device consists of a pair of chording gloves. Its keys are mounted on the fingers and their chording methods are similar to those of a Braille keyboard. RF (Radio Frequency) and IrDA (Infrared Data Association) modules are used to make the proposed input device wireless. Since the Braille representation for numbers and characters is efficient and has been well established for many languages in the world, the proposed input device may be one of good input devices to computers. Furthermore, since the Braille has been used for visually impaired people, the proposed one can be easily used as an input device to computers for them.

• 설비공학논문집
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• 제26권3호
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• pp.108-114
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• 2014

On a large scale of data center, heat generation rates from sever computers occupy almost the entire cooling load of the building, and it is gradually increasing. The efficiency of air distribution system in data centers can be affected by heat generation rates of server computers. In this study, the distributions of airflow and temperature in a data center have been investigated by CFD simulations under various conditions of heat generation rates for server computers. From the results, air around the cold aisle which has high temperature flows tremendously into the cold aisle according to the increase of heat generation rates for server computers and the air temperature in the cold aisle becomes higher. The SHI (supply heat index) and RHI (return temperature index) show almost similar values to the cases study because the air inflow rates to server computers increase with the heat generation rates of server computers.

• 시큐리티연구
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• 제4호
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• pp.279-298
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• 2001

Computers have produced significant benefits to society. Industrialized countries rely on their continuous availability and integrity, Computers have introduced innovations into the business world, communications media, and scientific community. In additions, as computers have developed, new categoris and methods of perpetrating crime have emerged that employ them.

• 정보교육학회논문지
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• 제2권1호
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• pp.19-34
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• 1998

For the purpose of adapting positively to the information society, it is very important to develop the capabilities of the retrieve, gather, process and application for informations by making efficient use of computers. So, with a view to understanding the importance of computer and adjusting actively to the information society, the systematic policy to cultivate the ability of making the most of computers is strongly demended. Therefore this study is to make a curriculum and guide for improving the capability of applying computers systematically, through analyzing a curriculum of computer in Elementary, Middle and High Schools, and to develop a model of grading system to cultivate the ability of applying computers, which grades capabilities of its practical use.

• 대한수학교육학회지:수학교육학연구
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• 제8권2호
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• pp.621-634
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• 1998

Emthusiasm about the introduction of computers into mathematics education is widespred. But, the perspectives about the relationship between mathematics education and computer are diverse. The purpose of this study is to examine theoretical background for using computers in mathematics education. In spite of the pedagogical possibilities of computers. only a small minority of mathematics teachers are using computers in mathematics classroom. It is natural to seek this obstacles within theoretical background of the teachers who manage computers, In this study, We discuss the problems in the two sides. First, due to increased computer activity, relationship of mathematics in school with mathematics in society is changing. It is tension between academic mathematics and practical mathematics. School mathematics have to be changed toward stressing practical mathematics. Second problem is the dialectical relationship between the individual and the collective. While maintaining a respect for the individuality of student contributions. We take into account the social dimension of mathematical meaning-making. We discussed theoretical clarification of work collaborative learning. We propose the case study for the roles of computer in collaborative mathematics learning.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2000년도 가을 학술발표회논문집
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• pp.40-47
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• 2000

One of the drawbacks of GA-based structural optimization is that the fitness evaluation of a population of hundreds of individuals requiring hundreds of structural analyses at each CA generation is computational too expensive. Therefore, a parallel genetic algorithm is developed for structural optimization on a cluster of personal computers in this paper. Based on the parallel genetic algorithm, a population at every generation is partitioned into a number of sub-populations equal to the number of slave computers. Parallelism is exploited at sub-population level by allocationg each sub-population to a slave computer. Thus, fitness of a population at each generation can be concurrently evaluated on a cluster of personal computers. For implementation of the algorithm a virtual distributed computing system in a collection of personal computers connected via a 100 Mb/s Ethernet LAN. The algorithm is applied to the minimum weight design of a steel structure. The results show that the computational time requied for serial GA-based structural optimization process is drastically reduced.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권9호
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• pp.4706-4726
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• 2019

The paper is devoted to the detailed description of the distributed system for gathering data from Windows-based workstations and servers. The research presented in the beginning demonstrates that neither a solution for gathering data on attacks against Windows based PCs is available at present nor other security tools and supplementary programs can be combined in order to achieve the required attack data gathering from Windows computers. The design of the newly proposed system named Colander is presented, too. It is based on a client-server architecture while taking much inspiration from previous attempts for designing systems with similar purpose, as well as from IDS systems like Snort. Colander emphasizes its ease of use and minimum demand for system resources. Although the resource usage is usually low, it still requires further optimization, as is noted in the performance testing. Colander's ability to detect threats has been tested by real malware, and it has undergone a pilot field application. Future prospects and development are also proposed.