• 전자통신동향분석
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• 제21권3호통권99호
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• pp.11-22
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• 2006

이동통신 시스템은 현재의 3세대 IMT-2000 시스템에 이르기까지 지속적인 진화를 거듭하였고 이제 사용자의 다양한 이동통신 서비스 요구 및 기대치를 충족시키기 위한 4세대 이동통신 시스템 및 서비스에 대한 관심이 지속적으로 증가하고 있다. ITU-RWP8F에서는 "보다 빠른 데이터 전송속도의 지원"과 "서로 다른 유무선 접속 시스템과 융합(convergence)"을 목표로 시간과 장소 및 대상의 구속이 없이 언제 어디서나 누구와도 고속 멀티미디어 통신 서비스를 지원하는 것을 차세대 이동통신 시스템의 비전으로 설정하고 있다. 이러한 차세대 서비스 비전을 실현하기 위하여 현재 WWRF, WWI, FMS, mITF, FuTURE Forum 및 NGMC Forum과 같은 주요 연구 단체는 개인의 관심사, 환경, 일상 생활이 고려된 각 개인의 통신 공간에서 상황에 따라 변화하는 개인의 요구사항이 반영된 차세대 서비스에 대한 연구를 수행하고 있다. 본 논문에서는 앞서 언급한 각 연구 단체가 수행중인 주요 연구 내용을 살펴보고자 한다.`

• 전자통신동향분석
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• 제21권3호통권99호
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• pp.79-90
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• 2006

CDMA 기술을 기반으로 하는 이동통신시스템의 발전과 DSL 기반의 유선통신시스템의 발전은 우리나라를 세계적인 정보통신 강국으로 성장시키고 있다. 세계적으로 높은 수준의 개인용 컴퓨터와 이동통신단말기 보유율을 바탕으로 폭발적인 인터넷서비스사용량의 증가뿐만 아니라 무선인터넷서비스에 대한 요구사항도 증가하고 있다. 이에 맞춰 무선 LAN은 고속의 가입자 전송속도를 지원하기 위해 발전하고 있다. 이미 high throughput을 목표로 하는 국제 표준화가 진행되어 마무리 단계에 있고, 이에 세계적인 칩셋 업체들이 앞다투어 IEEE 802.11n draft 이전의 EWC 버전을 이용한 칩셋을 발표하고 있다. 현재 ETRI에서는 802.11n draft 표준안을 기반으로 하는 칩셋 개발이 완성 단계에 이르렀으며, 이미 그 기능 및 성능에 대해 FPGA를 이용한 시스템 구축으로 확인하였다. 앞으로 네트워크, 오피스 네트워크 및 휴대폰 탑재 칩 등에 대한 대규모 시장 형성이 예상되고 있어 경제적 기대효과를 기대할 수 있다.

• 전자통신동향분석
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• 제19권1호통권85호
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• pp.9-21
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• 2004

차세대 통신 시스템은 다양한 IP 멀티미디어 응용을 지원하고, 유비쿼터스 서비스를 제공할 수 있도록 다양한 유무선 통신 시스템들이 IP 기반의 멀티네트워크로 통합될 것이다. 이러한 차세대 통신 시스템에서 IP 기반 멀티미디어 응용을 효율적으로 지원하기 위하여 종단간 QoS 제공이 중요한 문제가 된다. 본 고에서는 3세대 이동통신과 차세대 백본 네트워크(NGN)에서 연구되고 있는 QoS 제공 방안을 살펴본다. 그리고, 3세대 이후의 통신 시스템을 위하여 IP 네트워크에 기반을 두고 이질적인 무선 시스템들의 통합에 대해 연구하고 있는 프로젝트에서 All-IP화에 따른 종단간 QoS 제공 방안을 살펴본다. 그리고, 다양한 통신 시스템들이 IP 기반의 백본 네트워크로 통합되어 All-IP화된 차세대 통신 시스템의 개략적 구조를 제시하고, 이를 기반으로 종단간 QoS 제공을 위하여 연구되어야 할 주요 사항들을 살펴본다.

• 아동학회지
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• 제21권3호
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• pp.5-23
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• 2000

This study of the characteristics and the relationships of children's emotional intelligence (EQ) and self-esteem had a sample of 1060 5th grade children. The rank order of four EQ factors from highest to lowest was "perception of emotion", "other-regulation and self-expression", "self-regulation and emotion utilization", and "empathy". Among self-esteem factors, "general self-worth" had the highest correlation with overall self-esteem; "physical appearance" was most strongly correlated with "general self-worth". Relationships between EQ and self-esteem showed that higher EQ was associated with higher self-esteem. Among EQ factors, "other-regulation and self-expression" was the strongest predictor of "behavioral conduct." The next strongest predictor of self-esteem among EQ factors was "self-regulation and utilization of emotion". Other self-esteem factors well predicted by EQ were "general self-worth", and "scholastic competence".

• 가족자원경영과 정책
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• 제21권3호
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• pp.61-75
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• 2017

The Korean Family Resource Management Association(KFRMA) celebrated its $20^{th}$ anniversary in 2016. KFRMA has tried to improve the quality of family life through research and education since it was formed in 1996. The purpose of this study was to show the contributions of this association and to suggest the future direction. For these purposes, this study showed the process of development through themes of 40 symposiums and it analyzed the research trends among articles published in the Journal of KFRMA. Based on this evaluation, this study suggested an expansion of the research area, the identification of family resource management relating to family policies or healthy family services. Support for leading research projects and the training of healthy family specialists are needed in this association for next 20 years.

• 세라미스트
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• 제21권1호
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• pp.55-63
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• 2018

Recently, display technology has been focused in regard with with color reproduction, contrast ratio, image resolution and color bit. Among these technologies, the color reproducibliity of White, Red, Green, and Blue is associated with the TV plaform and is expressed as a major technology. Major TV platforms are divided into three categories since 2015, including LCD-based phosphor coverted LED BLU technology, QD sheet technology using nano-sized quantum dots, and OLED technology. In this paper, we describe the color reproducibility definition and background, luminescent materials with wide color gamut, color reproducibility of TV display performance, and discuss about next luminescent materials.

• 대한산업공학회지
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• 제21권4호
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• pp.555-570
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• 1995

We consider a preventive replacement policy for a cold-standby system with N components, in which only one component is in operation at a time. If the component in operation fails, a standby component is immediately switched into operation. If all components fail, the system fails. The system is inspected at random poins in time to determine whether it is to be replaced or not. If the number of failed components at the time of inspection exceeds a threshold value r, the system is replaced. Otherwise the decision is put off until the next inspection point arrives. Under the cost structure which includes a replacement cost, a system down-time cost and a holding cost of the components, we develop an efficient procedure to find the optimal control values N and r, which minimize the expected cost per unit time.

• 한국통신학회논문지
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• 제21권4호
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• pp.972-983
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• 1996

This paper proposes a new technique for frequency offset correction for OFDM systems on a frequency selective fading channel. Frequency offset in OFDM introduces interchannel interference among the multiple subcarriers of OFDM signal. To compensate the interference, this paper describes an algorithm with two stages:acquisition and tracking. At both stages, the proposed algorithm oversamples the received OFDM signal to obtain a couple of demodulated symbol sets. At acquisition stage the frequency offset is reduced to half or less of the intercarrier spacings by matching the sign pattern of each element of the sets. Next, at tracking stage the frequency offset is corrected with a frequency detector which is controlled by the correlation of the two sets. It is shown that the proposed algorithm can correct the frequency offset in the event of uncertainty in the initial offset that exceeds one half of the intercarrier spacing. In addition, the proposed algorithm is robust to transmitted symbols and channel characteristics by using oversampled symbol sets.

• 한국정보처리학회논문지
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• 제7권3호
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• pp.901-908
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• 2000

Satellite communication in the 21 century's high tech information world is developing rapidly, marked by high levels of applications and functions. For example, satellite communication can process and switch the speed of the service provided by a broad and vast digital multimedia system such as a long-distance all between nations or broadcasting transfer service, which is supplied by a contemporary satellite system. So, it bring about problems which lack of satellite orbit and gibes out frequency resource by increment of satellite universally. To support this, an OBP satellite system is need, which includes an on-board IF/RF switch, baseband signal processing, multi-beam antenna technology, as well as a simple transponder system. In this paper, we have outlined the next generation of satellite communication; satellite OBP transport network architecture, which offers multimedia service and applied frequency reuse method for multi-spot beam. The satellite B-ISDN transport network architecture is also analyzed.

• 한국품질경영학회:학술대회논문집
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• 한국품질경영학회 2006년도 춘계학술대회
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• pp.359-364
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• 2006

This document analyses the empirical study result of the safety quality management system(SQMS) induction. This analysis is composed as the following. First of all, we take a brief look at (he present Korean situations after the SQMS induction. Next, we analyse the effect of the SQMS induction, then we indicate the conclusion, suggestion, limits and future course of this study. We divided the effect of induction in 21 factors. The result was 3.5 out of 5 perfect Points, which shows the high preference. Higher points were scored with international companies than domestic ones, the companies accepted before 1998 than the ones after 1998, and large enterprises than smaller ones.