• Structural Engineering and Mechanics
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• v.66 no.6
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• pp.677-691
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• 2018

Reliability assessment of complex structures using simulation methods is time-consuming. Thus, surrogate models are usually employed to reduce computational cost. AK-MCS is a surrogate-based Active learning method combining Kriging and Monte-Carlo Simulation for structural reliability analysis. This paper proposes three modifications of the AK-MCS method to reduce the number of calls to the performance function. The first modification is related to the definition of an initial Design of Experiments (DoE). In the original AK-MCS method, an initial DoE is created by a random selection of samples among the Monte Carlo population. Therefore, samples in the failure region have fewer chances to be selected, because a small number of samples are usually located in the failure region compared to the safe region. The proposed method in this paper is based on a uniform selection of samples in the predefined domain, so more samples may be selected from the failure region. Another important parameter in the AK-MCS method is the size of the initial DoE. The algorithm may not predict the exact limit state surface with an insufficient number of initial samples. Thus, the second modification of the AK-MCS method is proposed to overcome this problem. The third modification is relevant to the type of regression trend in the AK-MCS method. The original AK-MCS method uses an ordinary Kriging model, so the regression part of Kriging model is an unknown constant value. In this paper, the effect of regression trend in the AK-MCS method is investigated for a benchmark problem, and it is shown that the appropriate choice of regression type could reduce the number of calls to the performance function. A stepwise approach is also presented to select a suitable trend of the Kriging model. The numerical results show the effectiveness of the proposed modifications.

• Journal of Multimedia Information System
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• v.4 no.4
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• pp.195-204
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• 2017

Mobile robots are used for years as a valuable research and educational tool in form of available open-platform designs and Do-It-Yourself kits. Rapid development and costs reduction of Unmanned Air Vehicles (UAV) and ground based mobile robots in recent years allowed researchers to utilize them as an affordable research platform. Despite of recent developments in the area of ground and airborne robotics, only few examples of Unmanned Surface Vehicle (USV) platforms targeted for research purposes can be found. Aim of this paper is to present the development of open-design USV drone with integrated multi-level control hardware architecture. Proposed catamaran - type water surface drone enables direct control over wireless radio link, separate development of algorithms for optimal propulsion control, navigation and communication with the ground-based control station. Whole design is highly modular, where each component can be replaced or modified according to desired task, payload or environmental conditions. Developed USV is planned to be utilized as a part of the system for detection and identification of marine and lake waste. Cameras mounted to the USV would record sea or lake surfaces, and recorded video sequences and images would be processed by state-of-the-art computer vision and machine learning algorithms in order to identify and classify marine and lake waste.

• Journal of Labour Economics
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• v.26 no.3
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• pp.49-75
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• 2003

This paper empirically examines multiskill formation as a critical mechanism of human capital accumulation within the firm. We investigate various factors that foster multiskill formation of the employees at the workplace. We also investigate whether and how multiskill formation of the employees, in tum, affect the labor productivity. Our empirical results are summarized as the following. First, skills of the employees are developed along the sequential path rather than the parallel path. They evolve from the simple-skill to the single-skill, and then to the multi-skill state. Second, multi skilling is stimulated by uncertainty factors of the environment and various human resource management practices such as mutual learning among workers, workers' participation in decision making, and job rotation. Third, the increase in the ratio of multiskilled workers in the firm has a positive impact on the growth of the firm's labor productivity. Our analyses show that the labor productivity growth increases by 0.019 with the increase in multi skilling ratio by 0.1. Fourth, uncertainty and human resource management practices had an indirect impact on labor productivity growth only through multiskilling. These results strongly indicate that multiskilling is a result of human capital accumulation fostered by various human resource management practices.

• Journal of Korean Library and Information Science Society
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• v.46 no.1
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• pp.241-269
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• 2015

This study started from an understanding that a true welfare society requires voluntary 'sharing' of citizens in addition to the state's legal and institutional security and that to make the culture of sharing find a firm ground in our society, 'Philanthropic Education' is needed from the childhood. This study examined three issues; first suggested the need of philanthropic education and learning methods. secondly, to find out the present situations of sharing in Korea, the study looked into sharing cultures and philanthropic education in other countries. thirdly, the study explored ways of philanthropic education for elementary school students of Korea in literature based program methods. The structure of the program was designed as structured experimental group program. And the content of this program is composed of concepts, objects, process, institutions regarding philanthropy, and finally practical behavior of it. This study implies that discussions in taking root and revitalizing the philanthropic education to encourage prosocial behaviors of children by more efforts of family, community and school.

• Journal of radiological science and technology
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• v.39 no.2
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• pp.247-256
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• 2016

This study was conducted with a goal to identify the factors that determine radiology students' satisfaction with their major and to provide the basic data for efficient education and career guidance. The result indicated that the students' satisfaction with the professors' roles was high. However, overall, the level of satisfaction with the curriculum was found to be low. In addition, it was analyzed that there was a large gap between recognition and practice of self-directed learning. In the correlation analysis, the professors' roles were also found to be a very important factor. Based on the result, the professors' roles of center(teaching or state examination, students with questions etc.,), it was concluded that improvement of the radiology students' satisfaction with their major would help the students adapt themselves to the major and school successfully and develop a positive character to perform as professionals in the future.

• The Korean Journal of Applied Statistics
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• v.21 no.5
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• pp.765-774
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• 2008

Korean financial markets are rapidly integrating into the world financial markets as they are getting to open more widely. The Korean government enacted new law about financial investments. The environment of domestic financial markets are expected to be more competitive. As a result, the learning demand for financial engineering has been increased. However, the current state of education of financial engineering is in a beginning stage. The financial engineering consists of an appropriate mix of mathematics, statistics, finance and engineering. So interdisciplinary property of financial engineering requires lecturers to be cooperative to operate education of financial engineering. Another element of this education is cooperation of both academia and industry.

• Journal of the Korea Safety Management & Science
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• v.12 no.1
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• pp.51-57
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• 2010

Cycling that transform human energy into mechanical energy is one of the man-machine systems out of sports fields. Benchmarking means "improving ourselves by learning from others', therefore benchmarking toward dominant cyclist is necessary on field. The goals of this study were to provide important factors on multi-disciplines (kinematics, physiology, power, psychology) for a tailored-training program that is suitable to individual characteristics. Two cyclists participated in this study and gave consent to the experimental procedure. One was dominant cyclist (years: 21 yrs, height: 177 cm, mass: 70 kg), and the other was non-dominant cyclist (years: 21, height: 176, mass: 70). Kinematic data were recorded using six infrared cameras (240Hz) and QTM (software). Physiological data (VO2max, AT) were acquired according to graded exercising test with cycle ergometer and power with Wingate test used by Bar-Or et. al (1977) and to evaluate muscle function with Cybex. Psychological data were collected with competitive state anxiety inventory (CSAI-2) that was devised by Martens et. al (1990) and athletes' self-management questionnaire (ASMQ) of Huh (2003). It appears that the dominant's CV of ankle joint angle was higher than non-dominant's CV and dominant's pedaling pattern was consistent in biomechanics domain, which the dominant's values for all factors ware higher than non-dominant's values in physical, and physiological domain, and their values between cognitive anxiety and somatic anxiety were contrary to each other in psychology. Further research on multi-disciplines may lead to the development of tailored-optimal training programs applicable with key factors to enhance athletic performance by means of research including athlete, coach and parents.

• KSCI Review
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• v.14 no.2
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• pp.235-244
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• 2006

This paper attacked the unknown DoS which mixed a DoS attack, Worm and the Trojan horse which used IP Source Address Spoofing and Smurf through the SYN Flooding way that UDP, ICMP, Echo, TCP Syn packet operated. the applications that used TCP/UDP in VoIP service networks. Define necessity of a Dynamic Update Engine for a prevention, and measure Miss traffic at RT statistics of inbound and outbound parts in case of designs of an engine at IPS regarding an Self-learning module and a statistical attack spread. and design a logic engine module. Three engines judge attack grades (Attack Suspicious, Normal), and keep the most suitable filtering engine state through AND or OR algorithms at Footprint Lookup modules. A Real-Time Dynamic Engine and Filter updated protected VoIP service from DoS attacks, and strengthened Ubiquitous Security anger, and were turned out to be.

• Journal of the Korea Society of Computer and Information
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• v.11 no.6 s.44
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• pp.165-174
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• 2006

This paper attacked the unknown DoS which mixed a DoS attack, Worm and the Trojan horse which used IP Source Address Spoofing and Smurf through the SYN Flooding way that UDP, ICMP, Echo, TCP Syn packet operated, the applications that used TCP/UDP in VoIP service networks. Define necessity of a Dynamic Update Engine for a prevention, and measure Miss traffic at RT statistics of inbound and outbound parts in case of designs of an engine at IPS regarding an Self-learning module and a statistical attack spread, and design a logic engine module. Three engines judge attack grades (Attack, Suspicious, Normal), and keep the most suitable filtering engine state through AND or OR algorithms at Footprint Lookup modules. A Real-Time Dynamic Engine and Filter updated protected VoIP service from DoS attacks, and strengthened Ubiquitous Security anger, and were turned out to be.

• Journal of The Korean Association of Information Education
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• v.10 no.1
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• pp.25-35
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• 2006

Computer education currently executed at elementary schools showed problems of system of education curriculum, repetition, and lack of consistent system as a result of analyzing index for information and communication technology, education curriculum, and related literatures, and most of the education contents have difficulty to nurture logic thinking and problem-solving ability since they are composed mainly of software function learning. Concerning this issue, this study suggests an innovated computer education curriculum with reinforced information ethics field with computer principle, algorithm, and programming, in other words, a corrected and supplemented version of former content system based on computer science guidance cases of ACM education curriculum model of USA, computer education curriculum of state Tennessee, and information technology education curriculum of Great Britain judging that introduction of computer science factors are desperate to improve computer education curriculum in elementary schools.