• 대한안전경영과학회지
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• 제10권2호
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• pp.95-103
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• 2008

The package loading process of the lumbering industry is an operation that after a pair of workers bind three or six lumbers into one unit and cut both ends of the lumbers, transports the weight cargo of 30-50kg by one meter, pack and load at a height of 1.2 meters. This package loading process causes lots of noise and wood dust when workers carry out the heavy work as the above. Therefore we developed the monolithic both ends cutting package loading equipment in order to prevent from getting musculoskeletal disease. An loading bar working system of this equipment is improved from pneumatic pressure system to oil pressure system, furnished the newly designed flow dividers, and developed the new system that a both end array is loaded identically. Also we developed the safety equipment of loading bar in order to prevent workers mistake and overload from malfunction during the package loading process. The main cause of job evasion on working place could be solved by preventing the musculoskeletal disease and improving the working environments.

• 디지털융복합연구
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• 제6권2호
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• pp.127-134
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• 2008

The aim of this study is to show that using a Web-Based Instruction system is a better method to help counteract deficient teaching, learning conditions and facilities thus improving the students' interest, understanding, participation and skill development in Physical Education. The key findings of this study are as follows; The first advantage of using this system is that the theory of Softball is explained with the use of pictures rather than text, thus improving the students' understanding. The second is the method in which practical skills are explained and demonstrated. Action image sequences are used as opposed to the old method of using stationary pictures. This means that the learners can clearly see and understand why and, more importantly, how to use these skills. The third advantage is the technique used to teach the application of these skills. Using active rather than passive learning and thus engaging the student encourages improved participation and learning. The fourth advantage comes in evaluation: both subjective and objective questions are asked in theoretical evaluation, and the teachers can evaluate the students' understanding and skill development by filming their actual Softball games. The final advantage is the use of Self-Directed Learning to aid learners' development of understanding of the lesson content as interactions between teachers and learners are constructe

• 시스템엔지니어링학술지
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• 제8권2호
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• pp.19-25
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• 2012

As modern weapon systems have evolved into embedded software systems, the capability to develop, install, and maintain high-quality software products is becoming increasingly valuable in today's competitive aerospace and defense industry. It is desirable, especially for government-contracted projects whose end-users are military personnel, that specific types of software quality elements are assured early during product development; namely, functionality and usability. Motivated by this need to approach improving software quality from a user's perspective, this paper presents a case study that analyzes system-level software integration testing results for a weapon system indigenously developed in the Republic of Korea. Quantitative data, such as software defect ratios and configuration change rates, are computed to observe meaningful trends with respect to functionality - represented by tests designed to verify the system's electrical signal interfaces - and usability, which is evaluated in terms of how often the initial human-computer interface had to be re-designed. Insights gained from these exercises are subsequently presented as a set of "lessons learned" to take into account when developing new software items for complex weapon systems.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2087-2092
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• 2005

Using disturbance observer (DOB) is effective in enhancing the performance of dynamic system in the presence of disturbances. Recently the definition of disturbance has been expanded to modeling uncertainty including parameter variation, internal disturbance. Various structures of DOB have been proposed to improve sensitivity of system for better disturbance rejection performance. However in the case of improvement of sensitivity function, it tends to bring poor transient response due to cross-coupling and phase lag. Furthermore it could be very sensitive to measurement noise due to increased peak of complementary sensitivity function. In this paper, a dual disturbance observer (Dual-DOB) is proposed to reduce the effect of such cross-coupling. It is possible for us to improve the sensitivity function with additional external DOB with hardly affecting complementary sensitivity function. Thus it is able to have robustness against measurement noise. Since we are able to design DOBs of internal and external loop independently, we could prevent transient response quality from degrading while improving the sensitivity function. The proposed Dual-DOB is applied to a commercial optical disk drive tracking servo system. The experimental result shows that the Dual-DOB is an effective method in rejecting the disturbance as well as improving the tracking performance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권10호
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• pp.5143-5158
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• 2018

Improving the intrusion detection system (IDS) is a pressing need for cyber security world. With the growth of computer networks, there are constantly daily new attacks. Machine Learning (ML) is one of the most important fields which have great contribution to address the intrusion detection issues. One of these issues relates to the imbalance of the diverse classes of network traffic. Accuracy paradox is a result of training ML algorithm with imbalanced classes. Most of the previous efforts concern improving the overall accuracy of these models which is truly important. However, even they improved the total accuracy of the system; it fell in the accuracy paradox. The seriousness of the threat caused by the minor classes and the pitfalls of the previous efforts to address this issue is the motive for this work. In this paper, we consolidated stratified sampling, cost function and weighted Support Vector Machine (WSVM) method to address the accuracy paradox of ID problem. This model achieved good results of total accuracy and superior results in the small classes like the User-To-Remote and Remote-To-Local attacks using the improved version of the benchmark dataset KDDCup99 which is called NSL-KDD.

• 해양환경안전학회지
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• 제15권2호
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• pp.143-149
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• 2009

경제 사회적 발전과 주 5일 근무제의 시행으로 국민들 삶의 질이 향상되고 좀 더 다양한 삶을 추구하고자 하는 가치관이 형성됨으로써 다양한 유형의 레저활동이 급격하게 증가하고 활성화되고 있는데 특히, 해양에서의 레저활동이 지속적으로 증가하고 있다. 그 중에서도 스킨스쿠버다이빙은 해양레저활동의 높은 비율을 차지하고 있지만, 동 활동의 안전에 관한 법규는 배우 미비하다. 이에 본 논문은 스킨스쿠버다이빙의 안전성을 향상시키고 또한 활성화시키기 위하여, 동 활동과 관련한 여러 법적 쟁점을 논의하고 고찰하여 문제점을 확인하고 개선방안을 도출하고자 한다.

• 농촌계획
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• 제17권1호
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• pp.79-88
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• 2011

In order to improve the quality of life and support the successful living of the elderly people in rural community, the Senior Well-being Villages Project has been carried out by Rural Development Administration since 2005 in Korea. This timely project, however, produces good results with 582 villages so far, we must endeavor to upgrade it more effectively. This study is to find complementary way of improving the project, and the results of the study are summarized as follows. First of all, the sustainable and practical strategies of the health care for the rural elderly must be adopted. The elderly people's mutual care system can be a good option for improving the existing project. Secondly, the cooperative heath care system must combine with this project. In this regards, health cooperative federation system can be also a challenging option. The beneficially activity of rural elderly people, which is a component of this project, must be linked with rural social enterprise or community venture. The local experts or capable men of various fields including family, the aged problem, social welfare, and regional development, must be appointed, and the support system enables them to do their jobs actively in the Senior Well-being Villages Project as well as other community works.

• 조명전기설비학회논문지
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• 제26권1호
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• pp.66-74
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• 2012

This paper propose a improved direct torque control(DTC) system for improving operation of five-phase squirrel-cage induction motor(IM). A five-phase IM drives present unique characteristics due to the additional degrees of freedom and also drives possess many others advantage compared with the traditional three-phase motor drive system, such as reducing a amplitude of torque pulsation and increasing the reliability. In order to maximize the torque per ampere, the proposed motor has concentrated windings and the produced back-electromotive force(EMF) is almost trapezoidal, and the motor is supplied with the combined sinusoidal plus third harmonic of currents, there is necessary to controlled 3rd harmonic current. Also a DTC method is advantageous when it is applied to the five-phase IM, because the five-phase inverter provides 32 space vectors in comparison to 8 space voltage vectors into the three-phase inverter drive system. For presenting the superior performance of the proposed DTC, experimental results of speed control are presented using a 32-bit fixed point TMS320F2812 DSP with 1.5[hp] IM.

• 전력전자학회논문지
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• 제5권4호
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• pp.377-385
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• 2000

본 논문에서는 국내 최초로 설치된 Custom Power기기인 배전용 STATCOM(STATic COMpensator)의 기기 신뢰성 확보를 위힌 기가 테스트 및 설계통 운전 분석결과를 보이고 있다. Custom Power는 유연송전시스템(FACTS : Flexible AC Transmission System)과 같이 교류전력계통을 제어함으로써 효율적이고 유연한 전력계통의 운용과 구성을 목적으로 한다. STATCOM은 Custom Power기기의 한 형태로 무효전력 보상, 전압조정, 그리고 전압 퓰리커 억제 등의 기능을 가진다. 본 논문에서는 STATCOM 시운전 결과 무효전력과 역률 보상에서 우수한 성능을 보임을 확인할 수 있다.

• 대한조선학회논문집
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• 제42권6호
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• pp.566-574
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• 2005

Reduction of a ship's rolling is the most important performance requirement for improving the safety of the crew on board and preventing damage to cargos as well as improving the comfort of the ride. A mass driving anti-rolling system (MO-ARS) might be one candidate of several systems against the ship's rolling. As the movable range of the mass on the ship is finite, the control system must include restriction on the mass position to protect the device and the ship. This restriction usually causes windup phenomenon and control performance is deteriorated seriously. Two control algorithms, anti-windup control and saturated sliding mode control, are studied in this paper. Control performance and robustness problem are checked out by numerical simulations.