• Journal of Welding and Joining
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• v.11 no.2
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• pp.27-41
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• 1993

The estimation of nugget sizes was attempted by utilizing the artificial neural networks method. Artificial neural networks is a highly simplified model of the biological nervous system. Artificial neural networks is composed of a large number of elemental processors connected like biological neurons. Although the elemental processors have only simple computation functions, because they are connected massively, they can describe any complex functional relationship between an input-output pair in an autonomous manner. The electrode head movement signal, which is a good indicator of corresponding nugget size was determined by measuring the each test specimen. The sampled electrode movement data and the corresponding nugget sizes were fed into the artificial neural networks as input-output pairs to train the networks. In the training phase for the networks, the artificial neural networks constructs a fuctional relationship between the input-output pairs autonomusly by adjusting the set of weights. In the production(estimation) phase when new inputs are sampled and presented, the artificial neural networks produces appropriate outputs(the estimates of the nugget size) based upon the transfer characteristics learned during the training mode. Experimental verification of the proposed estimation method using artificial neural networks was done by actual destructive testing of welds. The predicted result by the artifficial neural networks were found to be in a good agreement with the actual nugget size. The results are quite promising in that the real-time estimation of the invisible nugget size can be achieved by analyzing the process variable without any conventional destructive testing of welds.

• Journal of Digital Convergence
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• v.10 no.11
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• pp.351-358
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• 2012

This study is aimed at suggesting optical communication equipment that can deliver high quality video information in high speed, to efficiently handle the flood and water pollution in the river basin. This system is cheaper than existing equipment, and can monitor optical Internet as well as the condition of equipment. Generally, the communication equipment to prevent flood is installed in an unmanned control box and operated by the flood control office situated at the fiver mouth in a long distance section. Therefore, it is hard to promptly cope with communication interruptions, which occur by the cutting or aging of the optical cable. Under the circumstances, this study suggested an efficient system that can deliver high quality video information in high speed (Optical Transmission Convert System) by using optical fiber. The system also solves problems by making use of automatic protection switching (APS) when an accident happens. Its real-time monitoring function gives notice of the problem-occurring points. The system is expected to be widely used in various areas such as intelligent traffic systems.

• Journal of Korean Society for Quality Management
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• v.47 no.1
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• pp.187-198
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• 2019

Purpose: In this study, a reliability prediction based reliability growth management is suggested especially for the early development phase of a system and the case study of surveillance system is given. Methods: The proposed reliability prediction based reliability growth management procedures consists of 7 Steps. In Step 1, the stages for reliability growth management are classified according to the major design changes. From Step 2 to Step 5, system reliability is predicted based on reliability structures and the predicted reliabilities of subsystems (Level 2) and modules (Level 3). At each stage, by comparing the predicted system reliability with that of the previous stage, the reliability growth of the system is checked in Step 6. In Step 7, when the predicted value of sustem reliability does not satisfy the reliability goal, some design alternatives are considered and suggested to improve the system reliability. Results: The proposed reliability prediction based reliability growth management can be an efficient alternative for managing reliability growth of a system in its early development phase. The case study shows that it is applicable to weapon system such as a surveillance system. Conclusion: In this study, the procedures for a reliability prediction based reliability growth management are proposed to satisfy the reliability goal of the system efficiently. And it is expected that the use of the proposed procedures would reduce, in the test and evaluation phase, the number of corrective actions and its cost as well.

• Journal of IKEEE
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• v.9 no.2 s.17
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• pp.79-86
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• 2005

Increasing network traffic and multimedia application services need realtime analysis of network traffic for improvement of QoS and effective management of network resource. Because difficulty of measurement based on software method, study of meter architecture for efficient capture function is necessary. Therefore we design and implement hardware metering system for efficient packet capture using embedded linux. And we analyze required bandwidth of system bus and memory for 10Gbps traffic through simulation.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2003.02a
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• pp.63-68
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• 2003

현 방제작업의 노동집약적, 비효율적, 작업기피성 등을 고려할 때, 농산물의 경제적 생산을 위한 소형무인 항공방제기술을 개발하여 효율적이며 안정된 생산과 농업종사자의 작업환경을 개선하고 생력화함으로써 품질 및 가격에서 경쟁력을 갖출 수 있다. 연구에서 고찰한 내용을 요약하면 다음과 같다. \circled1 노동강도가 큰 수도작의 발제작업 및 적기성에 있어서 항공방제기술의 도입이 절실하다. \circled2 소형헬기의 작업능률은 30-50 ㏊/day로 소규모 지역에서 효율적으로 수행할 수 있다. \circled3 ULV (ultra low volume) 항공방제용 등록약제의 실적용이 가능하다. \circled4 일본의 경우 무인헬기를 이용한 방제 연면적은 44만 ㏊에 이르고 점차 증가하고 있다. \circled5 적기방제, 소규모 정밀방제, 환경과 소음 대책이 타 방법에 비하여 양호하다. \circled6 무인헬기를 이용한 방제작업은 작업자의 노동강도를 현저히 줄일 수 있다. \circled7 농업항공협회 등 안전운용체계를 확립하여 소형헬기의 안전한 운용을 추구해야한다. 현재 일부 방제 및 파종에 사용되는 유인헬기가 외국으로부터 도입되어 일부 사용되고 있으나 상기의 이유로 무인으로 작업이 가능한 소형 헬기의 개발이 절실한 실정이며 특히 항법시스템은 국가 간 기술적으로 폐쇄성이 강한 분야로 독자개발이 필요하다. 소형 무인 헬기의 농업이외의 적용 분야는 많으며 상업용 촬영, 군경용 감시 및 레저용 등으로 그 경제/산업적 파급 효과는 크다 하겠다.

• Journal of Broadcast Engineering
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• v.4 no.1
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• pp.22-31
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• 1999

Moving object tracking improves the efficiency and qualification for observation system, broadcasting system, video conference, etc. This paper propcses an improved Bayes decision method for detecting and tracking moving objects in active camera environment. The Bayes decision based tracking approach finds the region of moving objects by analyzing the image sequences statistically. The propcsed algorithm regenerates the probability density function to accord with moving objects and background for active camera. Experimental results show that the algorithm is accurate. reliable and noise resistant. The result is compared with those of the conventional methods.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.28-30
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• 2002

The increasing application of electronic equipment has heightened the interest in power quality in recent years because there are economic impacts on utilities, customers, and suppliers of load equipment. The power quality would impose result in severe damage on many industrial customers. As having been supplied many kinds of electronic devices such as computer and communication equipment, automation equipment and various kinds of control devices etc., it comes to be more and more difficult to maintain the clean power quality. According to the restructuring in electricity industry the power quality may be treated as goods as contract terms and regulation elements between power supplier and consumer in the near future. Under the above environment, the power quality should be monitored for all day long with appropriate devices which is possible to measure and record the associated power quality data to prove each responsibility for the impacts when disputes arise due to power quality problems power quality problems are occurred. In this paper the authors propose some functions to be considered and system configuration to monitor the associated power quality elements in developing the web based power quality monitoring system.

• Journal of the Korean Society of Radiology
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• v.5 no.6
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• pp.351-355
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• 2011

In this paper, monitoring system and platform of plant growth are suggested which are required by safe crop management about disaster and radiation pollution. In addition, by monitoring plant growth, the growth of plants that can measure the size of the efficient system was developed. The expected effect of this study, first, through natural disasters and radioactive contamination monitors produce fast and accurate response function can result in improved quality and productivity. Second, the size of the plant required to maintain the measurement data can save time and expense savings. Finally, plant managers can improve work efficiency.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.1
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• pp.163-168
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• 2016

For the quality increase of agricultural and aquatic products, it is necessary to the efficient management system of integrated control and accurate data for improving the water quality of reservoirs. This may be using the USN save time and money. In this paper, the water surface robot was designed and manufactured for measuring and announcing the environment informations, and it's network was constructed. The robot had more excellent durability and was more inexpensive than previous model. The network was designed considering connection with ZigBee, TRS, Wi-Fi or LTE network. Also the exploration function of the robot was confirmed by the simulation and the user interface was programmed.

• Journal of Korea Multimedia Society
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• v.13 no.1
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• pp.83-92
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• 2010

Sensor networks applications can be employed by a vast range of applications. Environmental information monitoring systems and ecosystem surveillance are representative application using sensor networks. But, limited battery capacity of sensor node is a key feature that determines lifetime of networks and system. It also affects quality of collected data. We recognized factors that affects lifetime of environment sensor nodes through the experiment of environment information system deployed over campus. We will show useful proposals for future construction of sensor network application systems.