• Journal of the Korea Safety Management & Science
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• v.10 no.2
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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.

• Journal of Digital Convergence
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• v.6 no.2
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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

• Journal of the Korean Society of Systems Engineering
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• v.8 no.2
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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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• 2005.06a
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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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• v.12 no.10
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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.

• Journal of the Korean Society of Marine Environment & Safety
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• v.15 no.2
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• pp.143-149
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• 2009

The marine leisure activities are specially increasing among the other leisure activities due to the improving of people's life quality and formation of people's values which pursuit the various life styles with the development of economy and society and operation the system of five working days per week. Among the various marine leisure activities, skin scuba diving is the mast prevalent activity, even though it doesn't have proper legal system in relation to the safety of the activity. Thus, this paper studies the various legal issues in relation to skin scuba diving to improve the safety and activation of the activity, and identifies the problems and proposes the ways of improving it.

• Journal of Korean Society of Rural Planning
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• v.17 no.1
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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.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.1
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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.

• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.4
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• pp.377-385
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• 2000

This paper presents the test and operation results of the domestic demonstration of the reactive power compensation device called STATCOM (STATic COMpensator). The object of the paper is to describe the reliability of the unit based on the extensive operation databases. The custom power is similar in nature to the concept of FACTS(Flexibel AC Transmission System). By controlling reactive power, the technology offers utilities the opportunity for increased efficiency and their capabilities will permit transmission planners make the best use of their existing transmission resources. STATCOM is a custom power device in a way and can be used in a similar way for the dynamic compensation of power transmission systems, providing reactive power compensation, voltage regulation and mitigation of voltage flicker. It is shown that the STATCOM has clear advantages in areas such as; providing reactive power compensation and improving power factor.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.6 s.144
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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.