• Information and Communications Magazine
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• v.16 no.10
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• pp.64-74
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• 1999

무선 채널에서 제한된 주파수 대역폭을 최대로 활용하여 비디오 데이터를 전송하기 위해서는 고효율의 변복조 기법, 페이딩 보상 기업 및 효율적인 오류 정정 기법이 요구된다. 본 고에서는 RF 주파수가 2GHz 대역이고 주파수 대역폭이 200 KHz를 갖는 TDMA 방식에 의한 WLL 모뎀(이하 AdWiLL$^{TM}$이라 한다) 설계에 대하여 기술한다. AdWiLL$^{TM}$모뎀의 핵심 기술로는 채널 특성을 실시간으로 분석하여 최적의 송수신 조건을 결정하는 channel probing 기술, 페이딩 환경에서 다중 레벨 QAM변복조를 가능하게 하는 적응출력제어 기술, WLL전파 환경과 서비스가 고려된 연접 부호(concatenated coding)를 통한 순방향 오류 정정(FEC) 기술, 송수신 성능 향상을 위한 범포밍 기술이 포함된다. 구현된 모뎀으 고정 무선 채널 환경에서 16 채널에서 32Kbps ADPCM 음성 신호를 동시에 송신할 수 있으며, 협대역 ISDN에서 제공하는 전송속도로 비디오 데이터의 전송이 가능함을 보였다.

• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.188-188
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• 2017

• Proceedings of the Korean Society of Disaster Information Conference
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• 2023.11a
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• pp.211-214
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• 2023

본 연구의 목적은 안전행동과 사고 발생을 예측하고 관리하기 위해 안전성향검사 도구를 개발하고 타당도를 검증하는 것이었다. 안전 심리 분야에서 근로자의 안전 행동에 영향을 미치는 주요 변인으로 안전 리더십과 안전 문화에 대한 연구들이 많이 진행되어 왔다. Lewin에 따르면 Behavior = Person * Environment으로 환경은 물리적 환경(기계, 장비 등)과 심리-사회적(psyco-social) 환경(안전 리더십/문화)으로 구분할 수 있다. 하지만 국내의 경우 근로자 개인 특성이 안전 수행에 미치는 영향에 대한 연구는 부족하였다. 개인 특성 중 일관되게 행동에 영향을 미칠 수 있는 변인이 성격이고, Lee 등(2018)은 개인 성격이 안전/불안전 행동에 영향을 미칠 확률은 35% 이상이며, 불안전 행동으로 한정해 보면 50% 이상이라고 하였다. 그리고 불안전한 행동으로 인한 사고는 비교적 소수의 직원에 의해 발생한다고 하였다(Clarke & Robertson 2008). 따라서 안전/불안전 행동을 예측할 수 있는 성격 특성을 검증하여, 직원 선발이나 재직자 코칭에 활용한다면 산업 재해 예방에 도움이 될 수 있다

• Journal of Convergence for Information Technology
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• v.9 no.8
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• pp.63-73
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• 2019

The purpose of this study is to examine the effects of nursing work environment and reciprocity on job embeddedness in the small and medium size hospital nurses. The data were collected from questionnaires filled out by 206 nurses. Data collection was performed from March 4 to 22, 2019. The collected data were analyzed by SPSS 25.0 program. As a result of the research, the study model accounted for 66.0% of job embeddedness. The most powerful variable affecting job embeddedness was support system of nurse, among sub - variables of nursing work environment. Therefore, nursing managers should improve the nurse's job embeddedness by creating nursing work environment that supports nurses such as salary improvement, professional development and promotion opportunities. In addition, it suggests that improvement of hospital and nursing organization system is needed to maintain cooperative relationship with nursing team or other health care professionals.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.05b
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• pp.480-483
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• 2003

3D 가상환경 개발 초기 단계에서부터 효과적인 Navigation 을 위해서 Navigation Aid 에 대한 연구가 꾸준히 진행되어왔다. 그러나 지금까지는 환경 구조의 중요 지점만을 정리한 요약 형태의 정보를 제공하는 방법이 주를 이루고 있어서, Navigation 대상 환경에 익숙지 않은 사용자에게 환경구조를 이해하게 하는 Cognitive Load를 주고 있다. 본 논문에서는 주제를 이동 또는 세분화하는 과정을 통해 원하는 지역 또는 대상을 선별하여 찾아내고 이를 3D 가상환경에서의 이동으로 연결하는 온톨로지 기반의 Navigation Aid 를 제안했다. 따라서 Navigation 대상 환경 구조에 익숙지 않은 방문자라도 유용하게 사용할 수 있으며, 환경을 구성하는 객체들의 위치가 자주 변하더라도 사용자에게 동일한 Navigation 환경을 제공하는 장정을 갖는다.

• The Journal of the Korea Contents Association
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• v.21 no.1
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• pp.520-530
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• 2021

This study conducted a meta-analysis on the variables related with case management performance in Korea. In order to do a meta-analysis, a total of 27 journals, theses and dissertations published between 1998 and 2020 were reviewed systematically. Through this process, this study calculated average effect size of each variable and explored moderator variables. This study results were as follows. First, this study identified a total of 14 individual, enviroment of institution, population variables related with case management performance. Second, the results indicated that case management performance variables which showed large effect sizes included professional capability, supervision, network, case management significance recognition, manual, agency support. Third, variables with medium effect sizes included self-efficacy, case management education, autonomy, motivation, number of conference and variables with small effect sizes included work experience, academic ability, age. Fourth, Moderator effects were identified in the field, target, publication of case management. Finally, the implications of the study findings were discussed.

• Korean Journal of Environment and Ecology
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• v.21 no.3
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• pp.278-289
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• 2007

This study investigated species formation and their vegetation on the roadsides of 1100 Road and 5 16 Road in Hallasan National Park from August 2004 to December 2006 to provide basic data for distributional attribute of the naturalized plants. The vascular plants investigated on the roadsides of Hallasan National Park were found to be 62 families, 145 genera, 197 taxa in total, in which naturalized plants were recorded as 11 families, 29 genera, and 37 taxa. The floristic formation at 1100 Roadside was composed of Festuca arundinacea-Dactylis glomerata association, which was again divided into Trifolium pratense-Plantago lanceolata sub-association and Sasa quelpaertensis-Gleichenia japonica sub-association. The florisitic composition of the 5 16 Roadside was sorted as Festuca arundinacea-Dactylis glomerata association, Oplismenus undulatifolius-Potentilla fragarisiiforlia, elatior association, Ambrosia artemisiifolia, and etatior-Persicaria thunbergii association. Among the naturalized plants distributed at this area, the annual plant accounts for 51.4%[19 taxa] and the plant of European origin accounts for 70.3%[26 taxa]. As for the background of the introduction of these plants, the case of introduction for forage or a mixture with grain and for pasture was 35.1% and 21.6% respectively, showing higher introduction circumstances than others. As shown in the study, most of the roadsides were occupied by the naturalized plants- Festuca arundinacea and Dactylis glomerata association and various naturalized plants; thus we can assume that it's because Festuca arundinacea and Dactylis glomerata association were mostly used for re-vegetation of the destroyed areas due to road construction or expansion or road maintenance and improvement project.

• The Journal of the Acoustical Society of Korea
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• v.18 no.1
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• pp.32-37
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• 1999

Rail noise and vibration is one of the major problem for the residents living nearby railway tracks. The rail noise may inflict a considerable damage to physiological, spiritual, mental and discomfort to neighboring peoples. Therefore, residents living nearby railway were appeal many troubles. Nevertheless, in our country, adequate guidelines for the rail noise are not yet established because of the lack of basic data and insufficient research works. In this point, this study attempts to surveys the influence of rail noise in urban area using questionnaire. This study also present a basic data in establishing effective plans for rail noise in the future.

• The Journal of the Acoustical Society of Korea
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• v.18 no.8
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• pp.3-8
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• 1999

Previous variable vocabulary speech recognition systems with context-independent acoustic modeling, could not represent the effect of neighboring phonemes. To solve this problem, we use allophone-based context-dependent acoustic model. This paper describes the method to improve acoustic model of the system effectively. Acoustic model is improved by using allophone clustering technique that uses entropy as a similarity measure and the optimal allophone model is generated by changing the number of allophones. We evaluate performance of the improved system by using Phonetically Optimized Words(POW) DB and PC commands(PC) DB. As a result, the allophone model composed of six hundreds allophones improved the recognition rate by 13% from the original context independent model m POW test DB.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.3
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• pp.20-27
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• 2006

Power line for digital home appliances has own property that transmitting power connected to loads. Especially, power line communication(PLC) for the home network which has characteristics of load fluctuation makes variable noise characteristics. It becomes serious problems to maintain efficient communication performance. Thus, in this paper, we present an optimal modulation and demodulation method through mathematical analysis of each measured load fluctuation based on PLC for home appliances. To analyze and compare various modem methods presented in this paper, we analyzed them normally via computer simulation under various noise channel environments according to various load fluctuations. In addition, we certified its availability through hardware implementation.