• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.7
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• pp.26-36
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• 2014

The needs of active phased arrays antenna system is getting more increased for IMT-Advanced system efficiency. The active phased array structure consists of lots of small transceivers and radiation elements to increase system efficiency. The minimized module of high efficiency transceiver is key for system implementation. The power amplifier of transmitter decides efficiency of base-station. In this paper, we design and implement minimized module of high efficiency transceiver for IMT-Advanced active phased array system. The temperature compensation circuit of transceiver reduces gain error and the analog pre-distorter of linearizer reduces implemented size. For minimal size and high efficiency, the implented power amplifier consist of GaN MMIC Doherty structure. The size of implemented module is $40mm{\times}90mm{\times}50mm$ and output power is 47.65 dBm at LTE band 7. The efficiency of power amplifier is 40.7% efficiency and ACLR compensation of linearizer is above 12dB at operating power level, 37dBm. The noise figure of transceiver is under 1.28 dB and amplitude error and phase error on 6 bit control is 0.38 dB and 2.77 degree respectively.

• Korean Journal of Social Welfare
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• v.61 no.1
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• pp.81-107
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• 2009

This study is to understand, in the view of resilience, the experience of military widows, whose husbands died while on active military duty and have lived as single mothers for a long time. This study using a qualitative research method based on Phenomenology, especially using Colaizzi's process of data analysis. 99 meaningful sentences, 26 themes, and 10 theme clusters has been categorized from the interview of 9 military widows, who has been participated a self-help group for them. The 10 theme clusters are 'denial and grief over the death of spouse', 'ambivalence over the duty of their husbands', 'acceptance of the helpless fate and arduous fight to live', 'sorrow in the social and historical context', 'responsibility and endeavoring of parenting', 'self-existential challenge', 'immanent belief system as a military widow'. 'effort to find self-identity in the outer systems', 'wish to reassure their existence', and 'to find the meaning of life after husband's dead'. These their self respect and feeling of honor have become their belief system in their life, which they have raised their children and take their responsibilities with their best effort. The self-help group has helped them to find their self-identity and has sustained emotionally healthy. This group has been also empowering them through their voices being heard to the outside society. They have made an effort which their existence is recognized by the country and the military system. The findings of this study can be used as a system to gather opinions and to provide information and program which may be accepted politically and then applicable and integrated social work service through the social support system and networking.

• Journal of The Korean Association For Science Education
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• v.32 no.10
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• pp.1567-1579
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• 2012

This study carried a survey to investigate teacher's cognition on preference and actuality about science laboratory and class environment targeting 262 science teachers. The results of this study are as follow: First, the actuality cognition of science teachers on science laboratory and class environment was lower than preference (p<.05). Second, there were no differences between preference and actuality regardless of gender (p<.05). However, the cognition on all of subordinates of preference appeared higher in females than males (p<.05). Third, at all levels of schools, preference is higher than actuality for science laboratory and teaching environment (p<.05). In case of preference, all of the subordinates indicated the difference between elementary and high school teachers (p<.05). On the other hand, in actuality there was a difference between elementary and middle school teachers in 'science laboratory facilities condition' domain only (p<.05). Fourth, the preference was higher than actuality in all school locations (p<.05). And in case of preference, there was no difference in all subordinates regardless of school sites. Whereas the cognition of small-medium city teachers was lower than metropolitan in actuality on the three domains of 'science laboratory facilities condition,' 'teaching condition and service support,' and 'staff policy and practice' (p<.05). As a result, this study informs that upgrading is necessary to achieve inquiry activity in science class in overall teaching environment including science classroom and laboratory.

• Culinary science and hospitality research
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• v.17 no.5
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• pp.74-91
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• 2011

The purpose of this study is to investigate the efficiency of a government-supported project developed to improve the quality and hygiene levels of food, service, and restaurant facilities for foreign customers in Chungnam province. Data was collected from 53 restaurant owners and restaurant managers. This study empirically analyzes and presents a mode with key factors influencing transfer of training and training satisfaction. Multiple regression analysis methods were used to test the relationships among four factors for transfer of training, training satisfaction, and retraining intentions. There are three main findings. First, teaching methods and relevance factors had a significant effect on transfer, but instructor and education environment factors did not. Second, the teaching methods, instructor and education environment factors had a direct influence on training satisfaction, but the relevance factor didn't. Third, transfer and satisfaction both were influenced significantly by retraining. Based on the findings of this study, a trainer, designing training curriculum for a production environment, should emphasize the role of the trainer and focus on learning tools. Finally, a thorough learning design is needed for learner's satisfaction.

• Proceedings of the CALSEC Conference
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• 1999.11a
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• pp.529-534
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• 1999

전자상거래는 구매자와 판매자 모두에게 많은 이점을 제공할 수 있어 최근 이에 관한 연구들이 많이 진행되고 있다. 특히 중소제조업체의 경우, 전자상거래라는 경영환경의 변화는 새로운 기회로 다가오고 있어, 상대적으로 기술력이 취약한 중소제조업체의 전자상거래를 지원하기 위한 요소 기술들의 개발 필요성이 점차 부각되고 있다. 이에 본 연구에서는 중소 금형제조업체의 판매과정을 사이버 공간에서 수행할 수 있는 전자상거래 기술을 개발하였다. 일반적으로 변화하는 경영환경에서는 생산과 관련된 계획과 통제가 보다 더 신속하고 정확하게 이루어져야 한다. 즉 전자상거래 환경에서의 제조업체는 구매자가 요구한 제품의 생산과 납기일을 맞추어 줄 수 있는지의 여부를 실시간으로 응답할 수 있어야 한다. 나아가서 인터넷을 통해 접수된 주문들은 해당 제조업체의 생산능력을 초과할 수 있는데 이 때에는 접수된 주문들 중에서 자사의 이익을 극대화할 수 있는 주문집합을 선별하여 접수여부를 결정해야 한다. 이와 같이 전자상거래 환경하에서의 제조업체는 생산과 관련된 정보를 신속하게 전달 받아 주문접수여부에 관한 의사결정을 올바르게 수행하는 것이 중요한데 본 연구에서는 중소 금형제조업체의 일정계획 및 주문처리를 위한 일정계획 기반의 선정 에이전트의 구조와 방법론을 제시하였다. 지금까지 일정계획에 관한 연구들은 대부분 납기일의 만족과 비용의 최소화 측면을 위주로 다루었다. 그러나 본 연구에서의 문제는 비용의 최소화보다는 납기일을 준수하면서 가장 많은 이익을 가져다 줄 수 있는 최적주문집합을 선정하는 문제를 다루고있다.자료를 수집하고, 통계분석 패키지를 이용하여 자료를 분석하였다. 방식을 결합한 하이브리드 형태이다.인터넷으로 주문처리하고, 신속 안전한 배달을 기대한다. 더불어 고객은 현재 자신의 물건이 배달되는 경로를 알고싶어 한다. 웹을 통해 물건을 주문한 고객이 자신이 물건의 배달 상황을 웹에서 모니터링 한다면 기업은 고객으로 공간적인 제약으로 인한 불신을 불식시키는 신뢰감을 주게 된다. 이러한 고객서비스 향상과 물류비용 절감은 사이버 쇼핑몰이 전국 어디서나 우리의 안방에서 자연스럽게 점할 수 있는 상황을 만들 것이다.SP가 도입되어, 설계업무를 지원하기위한 기본적인 시스템 구조를 구상하게 된다. 이와 함께 IT Model을 구성하게 되는데, 객체지향적 접근 방법으로 Model을 생성하고 UML(Unified Modeling Language)을 Tool로 사용한다. 단계 4)는 Software Engineering 관점으로 접근한다. 이는 최종산물이라고 볼 수 있는 설계업무 지원 시스템을 Design하는 과정으로, 시스템에 사용될 데이터를 Design하는 과정과, 데이터를 기반으로 한 기능을 Design하는 과정으로 나눈다. 이를 통해 생성된 Model에 따라 최종적으로 Coding을 통하여 실제 시스템을 구축하게 된다.the making. program and policy decision making, The objectives of the study are to develop the methodology of modeling the socioeconomic evaluation, and b

• Journal of the Korean Society for Railway
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• v.11 no.4
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• pp.349-356
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• 2008

Put Safety-critical systems related to the railway communications are currently undergoing changes. Mechanical and electro-mechanical devices are being replaced by programmable electronics that are often controlled remotely via communication networks. Therefore designers and operators now not only have to contend with component failures and user errors, but also with the possibility that malicious entities are seeking to disrupt the services provided by theirs systems. Recognizing the safety-critical nature of the types of communications required in rail control operations, the communications infrastructure will be required to meet a number of safety requirements such as system faults, user errors and the robustness in the presence of malicious attackers who are willing to take determined action to interfere in the correct operation of a system. This paper discusses the safety strategies employed in the railway communications and proposes a security mechanism for Korean railway communication system. We present the developed communication safety evaluation tool based on the proposed security mechanism and also evaluate its protecting capability against the threats of masquerading, eavesdropping, and unauthorized message manipulation.

• Journal of Korean Home Economics Education Association
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• v.21 no.1
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• pp.141-155
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• 2009

Purchasing used school uniforms is to reduce environmental pollution and expenses, and to enhance a feeling of wearing satisfaction for school uniforms by improving size fitting. In order to improve reutilization of used school uniforms, uniform purchasing behavior, awareness of the reutilizing markets of used school uniforms, and the running conditions of reutilizing markets of used school uniforms were analyzed through the survey. The subjects are 741 students of middle and high schools in Seoul and Kyeonggi Province in this study. The results are as follows. First, the better-fitted uniforms students wear, the higher satisfaction they feel. Therefore, it is desirable for students to wear the uniforms which are well fitted for each student. Second, the higher aware of environment students are and the more environmental preservation behavior they do, the higher awareness of wearing used school uniforms they are. In order to enhance students' awareness of reutilizing markets of used school uniforms, it is important to educate students about the environment systematically and to promote recycling events. Third, the reasons for not purchasing used school uniforms are difficulty in access to the repurchasing market and the sanitary problem. Therefore, it is suggested that environmental education which boosts students' awareness of environment and reutilization events should be held to make reutilizing markets of used school uniforms vigorous. Moreover, it is necessary to make reutilizing markets easy to access and improve cleaning and repairing system.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.28 no.4
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• pp.393-413
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• 2017

This study will explore the possibility of applying process innovation as a public library for business innovation. In order to do this, the study defines the concept of process innovation through the literature review. According to survey and focus group interviews with librarians working for public libraries, this study will organize work done at libraries into the following categories: acquisition, resource management, user management, user services, programs, volunteer management, marketing, library computerization system, facility management, general affairs and statistical management. In addition, through face-to-face surveys with librarians working for public libraries it is confirmed that there are issues within acquisition, user management, and applied process innovation. In response to these issues a new process has been developed. Using this new approach, book contract procedure and requests for book related work could be improved and optimized. In the user management section, the study analyzes the requirements and subscription procedures for members through a website survey of 30 public libraries in the United States and then provides an improved system through process analysis of the membership process of Korean public libraries. It is expected that the new system will contribute to improvements in user satisfaction as well as improvements in library workflow.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.10
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• pp.1040-1049
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• 2014

In this paper, a quad-band antenna for DCS1800, PCS1900, WCDMA, WLAN and Mobile WiMAX application is proposed. The proposed antenna is a printed monopole structure, and consists of two rectangular ring-shaped radiating patches on the front side and two different size of L-shaped slots on the back side(ground plane). Two rectangular ring radiation patches are respectively resonant at 2 GHz and 3.5 GHz bands, and additional resonance is occurred at 5.3 GHz by the coupling effect between two ring patches. In addition, the optimized matching characteristic is obtained by controlling the gaps. Also, by adding two L-slots on the ground plane, additional resonant frequency band of 5.6 GHz is occurred. Finally the measured bandwidths of the proposed antenna below -10 dB return loss are 1,200 MHz(1.6~2.8 GHz), 800 MHz(3.2~4.0 GHz), 300 MHz(5.14~5.44 GHz), and 690 MHz(5.56~6.25 GHz). The radiation patterns have the omni-directional characteristic, and the measured antenna average gains at resonant bands are 0.86~4.07 dBi.

• Archives of design research
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• v.15 no.3
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• pp.5-14
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• 2002

The amusement design of a large amusement park, including theme park, largely consists of attraction design, the main facilities, and auxiliary facilities design. The purpose of this study was to discuss the physical motion characteristics of major ride, a recently highlighted representative ride attraction, modern people's thirst for stronger stimuli, and some of the right future directions for amusement design. In theme park, there is an growing trend for rides, especially major rides, to be more thrilling, and Newton's Law motion is basically applied. The rides we can often see provides a thrilling experience that is different from that offered by vehicles we use everyday, due to a variety of speed change, namely of acceleration. Every entertainment facilities, including ride attractions, are externally cutting edge with the use of new technology. but internally, poor theme or concept not only makes it difficult to function properly as attraction but poses a severe threat to theme park survival itself. Theme park will be able to exist as a comprehensive entertainment entity, when attractions are designed to have a perfect harmony among story, method and environment with cultural universality.