• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.5
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• pp.542-548
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• 2001

A robust, accurate, broad-band, alternating current sensor using fiber-optics is being developed as a part of optical over current protection relay system. The sensor uses the Faraday effect in optical fiber and polarimetric measurements tc sense electrical current. The current sensing coil consists of a length of twisted optical fiber and Faraday rotator mirror to suppress the linear birefringence effect. Due to its single-ended closed path structure, it can not only be easily installed to the target with great isolation from other fields in the vicinity, but the sensitivity can be increased by using multiple turns. This paper reports on the theoretical backgrounds of the sensor design and the preliminary experimental results.

• Journal of the Economic Geographical Society of Korea
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• v.16 no.3
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• pp.512-527
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• 2013

This study examines the spatial distribution characteristics of financial industry which has been a necessary service for contemporary urban life. In particular, we analyze the spatial distribution patterns of money lending business which is considered with informal financial services as well as the spatial distribution patterns of banks which are representative of the institutional financial services. For the purpose, their density distribution patterns are explored by Kernel density analysis for both financial services in first. Moran's I coefficients are estimated for these two financial services to clarify the distintion in their geographical concentration patterns. The results of spatial autocorrelation analysis show stark differences between the center city and outskirts of the Seoul metropolitan area. Multivariate regression models are developed to explain the relationships between the spatial distributions of financial services and geographical variables. Finally, we discuss financial exclusion problem in the Metropolitan Seoul based on these spatial distribution characteristics.

• The Journal of the Korea Contents Association
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• v.16 no.3
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• pp.732-741
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• 2016

This research examines the relationships and effects among ROKAF officer's job satisfaction and psychological well-being and their self-leadership. Multiple regressions were conducted using 211 data. Results are as follows. First, Job satisfaction, psychological well-being and self-leadership were significantly positively correlated with each other. Second, as for the effects of subordinate factors among job satisfaction and psychological well-being on the subordinate factors of self-leadership, personal growth and controling environment of psychological well-being and administration of job satisfaction influenced self-expectation of self-leadership. For the self-reward of self-leadership, personal growth, meaning of life and autonomy of psychological well-being and relationship and reward system of job satisfaction influenced it. Finally, as for the effects of subordinate factors among job satisfaction and psychological well-being on self-leadership, administration and relationship of job satisfaction and personal growth, meaning of life and autonomy of psychological well-being influenced it. Finally implications and limitations of this research are discussed.

• Journal of The Korean Association of Information Education
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• v.7 no.2
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• pp.207-217
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• 2003

Individual studying that compose knowledge and improve efficiency of studying through collection of information by various class strategy which takes advantage of web, and Cooperative learning that can elevate sense of responsibility and solve the problem through communication with another person have been developed actively. But, individuation tutoring materials that is developed present doesn't fit of causing learner's interest, and stimulating curiosity about problem because mostly studying is gone in presentation form. Also, cooperative learning materials are lacking connection with actual course of education, application is difficult in real class spot. So, this research has applied self-directed learning, centered with interested operation activity, aimed at improvement in various thought. Also, we have developed social studies tuition-learning system, purpose to the management is possible with on-line project studying which could improve mind-decision ability and ICT application ability. This system is developed for flexible management could be possible in various class circumstance, and level learning could be done through accomplishment-test and the result could be applied by feedback process.

• The Korean Journal of Applied Statistics
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• v.29 no.5
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• pp.873-885
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• 2016

Onions are grown in a few specific regions of Korea that depend on the climate and the regional characteristic of the production area. Therefore, when onion yields are to be estimated, it is reasonable to use a statistical model in which both the climate and the region are considered simultaneously. In this paper, using a spatial panel regression model, we predicted onion yields with the different weather conditions of the regions. We used the spatial auto regressive (SAR) model that reflects the spatial lag, and panel data of several climate variables for 13 main onion production areas from 2006 to 2015. The spatial weight matrix was considered for the model by the threshold value method and the nearest neighbor method, respectively. Autocorrelation was detected to be significant for the best fitted model using the nearest neighbor method. The random effects model was chosen by the Hausman test, and the significant climate variables of the model were the cumulative duration time of sunshine (January), the average relative humidity (April), the average minimum temperature (June), and the cumulative precipitation (November).

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.937-940
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• 2010

21세기 정보화 세계화 사회에서 창의적이고 자율적인 인간양성을 위한 교육개혁으로 창의적 인재양성, 자기주도적 학습능력 배양이 강조되어지고 있다. 그럼에도 불구하고 제주지역 농어촌의 경우 인구 집중이 도시로 이루어지면서 농어촌의 인구가 감소되어지고 그러한 결과로 소규모 학교는 통폐합이되면서 교육여건은 악화되고 있는 실정이다. 이에 제주지역 농어촌 교육문제를 해소하여 학생들의 이농현상을 줄일 수 있으며, 창의적이고 자기주도적인 학습 능력을 배양할 수 있는 프로그램 개발의 필요성을 느끼게 되었다. 본 연구에서는 도시와 농어촌의 서로 다른 교육여건에 기반하여 교육내용을 특성화함으로써 제주지역 농어촌 학생의 창의적 문제해결력 향상을 위한 통섭적 활동 모형과 프로그램을 개발하기 위한 이론적 고찰을 하였다. 도시와 농어촌의 학력격차를 해소하기 위해서는 농어촌 학생에게 적절한 교육내용과 활동으로 재편성하여 가르칠 필요가 있다. 특히 제주도는 농촌과 어촌, 도시형이 특별히 구분되어지는 것이 아니라 하나의 통합된 생활문화의 특징을 가지고 있다. 앞으로 본 연구의 이론적 고찰을 바탕으로 제주지역 농어촌 학생들의 일상적인 생활환경에서 접하게 되는 다양한 활동 속에서 창의적으로 문제해결을 할 수 있도록 통섭적 활동 모형과 프로그램을 개발하여 적용하게 되면 학생의 역량을 강화시키고 잠재해 있는 창의적 문제해결력을 개발하여 학력향상에 기여할 수 있을 것이다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.11
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• pp.2411-2417
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• 2012

Globally, the emergence of smart phones vitalized the ecosystem of mobile data service industry. Consequentially, mobile data traffic has been explosively growing and the speed of growth will be more steep. New spectrum will be required in order to properly accommodate the explosively growing mobile data traffic. However, it will be difficult to acquire a sufficient guard band between different frequency bands because the range of frequency which is suitable for wireless communications is limited. Thus, the performance degradation caused by inter-band interference will be one of challenging problems in the next generation mobile communication systems. In this paper, we analyze the performance degradation caused by inter-band interference by computer simulations in various environments. Our results show that the impact of the inter-band interference is more critical when own signal is poor or its own interference from neighboring cells is low.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.7
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• pp.1266-1275
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• 2015

This review paper introduces recent results on interference management for full-duplex cellular systems. Interference management techniques for uplink-downlink cellular networks are frist introduced, which are closely related to those for full-duplex cellular systems. Self-interference suppression method for full-duplex radios and the corresponding modeling of full-duplex cellular systems are then explained. Even if self-interference is perfectly suppressed, there exists a new source of interference between full-duplex users for full-duplex cellular systems. Therefore, management of such user-to-user interference is of crucially importance to improve the capacity of full-duplex cellular systems. Recently, new interference management techniques for achieving the optimal sum degrees of freedom of full-duplex cellular systems have been proposed. In this review paper, these optimal interference management techniques are mainly introduced.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.3
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• pp.331-337
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• 2016

In this paper, we analyze performances of in-band full-duplex communication system and self-interference (SI) suppression methods in environment where there exists the SI signal. The SI has to be removed to achieve required error rate performance of the system in order - propagation domain, analog domain and digital domain. In propagation domain, the SI signal is attenuated by separating transmitted and received beams physically. In analog and digital domain, after reconstruction of the SI signal using channel estimates and transmit signal, the SI signal can be cancelled from the desired signal. In this paper, assuming that the SI signal can be sufficiently reduced in propagation domain, we demonstrate that the in-band full-duplex communication system can achieve the target error rate by suppressing the SI signal in order - analog and digital domain, based on channel estimates that can be obtained by the method of Least squares.

• Journal of Digital Convergence
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• v.16 no.1
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• pp.63-72
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• 2018

This paper examined the learning transfer of job training participants and its influencing factors. A survey of 279 care workers in the city of Seoul and Kyeong Gi province who recently participated dementia job training was conducted. The results of multiple regression analysis indicated that the self-efficacy of the care workers, the capability of instructor, the training methods and the transfer opportunity positively influenced the level of learning transfer. The findings suggested increasing care workers' self-efficacy, enhancing practical skill-based training program, hiring instructors with high workplace experiences, fostering work environment with higher transfer opportunity are required.