• 한국해안·해양공학회논문집
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• 제34권4호
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• pp.109-118
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• 2022

정점 표층 수온 관측 데이터 중 결측 구간의 데이터를 양방향 순환신경망(Bidirectional Recurrent Neural Network, BiRNN) 기법을 이용하여 보간하였다. 인공지능 기법 중 시계열 데이터에 일반적으로 활용되는 Recurrent Neural Networks(RNNs)은 결측 추정 위치까지의 시간 흐름 방향 또는 역방향으로만 추정하기 때문에 장기 결측 구간에는 추정 성능이 떨어진다. 반면, 본 연구에서는 결측 구간 전후의 양방향으로 추정을 하여 장기 결측 데이터에 대해서도 추정 성능을 높일 수 있다. 또한 관측점 주위의 가용한 모든 데이터(수온, 기온, 바람장, 기압, 습도)를 사용함으로써, 이들 상관관계로부터 보간 데이터를 함께 추정하도록 하여 보간 성능을 더욱 높이고자 하였다. 성능 검증을 위하여 통계 기반 모델인 Multivariate Imputation by Chained Equations(MICE)와 기계학습 기반의 Random Forest 모델, 그리고 Long Short-Term Memory(LSTM)을 이용한 RNN 모델과 비교하였다. 7일간의 장기 결측에 대한 보간에 대해서 BiRNN/통계 모델들의 평균 정확도가 각각 70.8%/61.2%이며 평균 오차가 각각 0.28도/0.44도로 BiRNN 모델이 다른 모델보다 좋은 성능을 보인다. 결측 패턴을 나타내는 temporal decay factor를 적용함으로써 BiRNN 기법이 결측 구간이 길어질수록 보간 성능이 기존 방법보다 우수한 것으로 판단된다.

• 한국응용과학기술학회지
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• 제38권6호
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• pp.1393-1404
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• 2021

본 연구는 장기요양 기관 종사자들의 감염관리에 대한 인지도와 수행도 현황조사를 통해 감염관리 실태를 파악하여 장기요양 기관의 종사자를 위한 효율적인 감염관리 및 교육 프로그램 개선을 위해 수행되었다. 연구 대상자는 C 지역의 장기요양 기관 35곳의 종사자 134명이며 2021년 7월 12일부터 7월 30일까지 구조화된 설문지를 사용하여 자료를 수집하였으며 SPSS 22.0 program을 이용하여 자료 분석하였다. 연구 결과 대상자의 감염관리 인지도에 영향을 미치는 요인은 종사자의 직종(F=3.181, p=.032), 감염관리 교육 경험(F=6.372, p=.013) 이었으며 감염관리 수행도 또한 종사자의 직종(F=3.972, p=.010), 감염관리 교육 경험(F=4.403, p=.038)이 영향을 크게 미쳤다. 대상자의 감염관리 인지도와 수행도는 양의 상관관계가 있었다(r=.919, p<.001). 본 연구의 결과를 종합해 볼 때, 코로나-19 팬데믹 상황에서 장기요양기관의 환자 안전을 위해서는 종사자가 감염관리 중요성을 인지하는 것뿐만 아니라 직접 감염관리 행위를 수행하는 것이 매우 중요하다. 이를 위해서는 기관의 규모에 상관없이 직종별, 교육 주제별 체계적이고 지속적인 교육과정 마련과 감염관리체계의 질적 향상을 위한 평가 시스템의 법적 강화가 필요할 것으로 생각한다.

• 정보학연구
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• 제9권3호
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• pp.77-89
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• 2006

The event study analyzes returns around event date at a time. Event study provides estimation periods and cumulative returns. Stock split announcements are generally associated with positive abnormal returns. It is important to investigate the responses of stocks to new information contained in the announcements of stock splits. So It is important to study the long term performance in the case of Stock Split. This Study forced to two approach method in evaluating the performance, the event time portfolio approach and calendar time portfolio approach. The event time portfolio approach exists the CAR model, BHAR model and WR model. And the calendar time portfolio approach has the 3 factor model, 4 factor model, CTAR model, and RATS model.

• 한국의류학회지
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• 제25권6호
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• pp.1079-1090
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• 2001

This paper suggest the importance of relationship marketing of the apparel store, and proved the relationship between the relationship marketing factors and the relationship quality and performance. In this research, department store is focused, Credence service, contact guest service, and communication service are defined as relationship marketing factors. Satisfaction and trust are defined as relationship quality. And long-term oriented relationship, repeat purchase. and positive word-of-mouth are set to performance. The questionnaire survey was carried out 238 20's & 30's women in the capital region during nov, 2000. SAS package program was used to analyze the gathered data. The investigation of this research reveals some results. First, relationship marketing factor has effects on relationship quality. Second, it is proved that relationship quality has effects on performance. In conclusion, it is proved that relationship marketing of apparel store is very important marketing strategy that make concrete relationship with consumer and give satisfaction and trust to consumer, and then can make partnership with consumer for long-term consideration.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 추계학술대회
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• pp.527-530
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• 2017

LTE-R(Long Term Evolution-Railway)은 LTE 기술을 기반으로 한 철도통신의 표준으로 고속철도의 핵심 통신기술로 사용될 것으로 전망된다. 본 논문에서는 LTE-R 네트워크에서 응용트래픽으로서 비디오 트래픽의 전송성능을 분석해 본다. 성능분석은 NS-2를 기반으로 한 컴퓨터 시뮬레이션을 사용하여 수행하며, 비디오 트래픽으로는 공개 영상 트래픽을 사용하며, 전송 프로토콜로는 RTP(Real Time Traffic)을 사용한다. 본 논문의 결과와 방법은 LTE-R 네트워크의 연구 및 개발에 활용될 수 있을 것으로 생각된다.

• Journal of information and communication convergence engineering
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• 제19권4호
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• pp.241-247
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• 2021

Particulate matter has emerged as a serious global problem, necessitating highly reliable information on the matter. Therefore, various algorithms have been used in studies to predict particulate matter. In this study, we compared the prediction performance of neural network models that have been actively studied for particulate matter prediction. Among the neural network algorithms, a deep neural network (DNN), a recurrent neural network, and long short-term memory were used to design the optimal prediction model using a hyper-parameter search. In the comparative analysis of the prediction performance of each model, the DNN model showed a lower root mean square error (RMSE) than the other algorithms in the performance comparison using the RMSE and the level of accuracy as metrics for evaluation. The stability of the recurrent neural network was slightly lower than that of the other algorithms, although the accuracy was higher.

• 대한지역사회영양학회지
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• 제20권3호
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• pp.220-235
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• 2015

Objectives: The purpose of this study was to investigate how clinical nutrition services is provided at a long term care hospital in Korea and to investigate job satisfaction levels of the clinical dietitians. Methods: Survey questionnaire was sent to dietitians working at a long term care hospital in Korea. The participating hospitals (n=240) were randomly selected from 1,180 long- term care hospitals using a stratified sampling method. A total of 134 long term care hospital s and 223 dietitians completed the survey of clinical nutrition service s and job satisfaction questionnaires The job satisfaction questionnaire included 27 job satisfaction questions on task, stability vision, working conditions, and relationship areas. Results: The average nutritional screening rate was 17.9% and the rate of computerized nutritional screening system was 9.7% in the participating hospitals. Nutritional intervention rate was only 3.2% of all patients. KOIHA (Korea Institute for Healthcare Accreditation) accreditated hospitals showed only 50% performance rate of nutrition service evaluation area. This shows that after achieving KOIHA accredition, many hospitals do not emphasize the performance of nutritional services. The job satisfaction scores in all four areas ranged from 2/5 to 3/5, implying generally low job satisfaction level in hospital dietitians. Linear regression analysis results showed that the "hospital adequacy grade" type was a significant predictor of job satisfaction level for two areas (working conditions & relationship). Conclusions: There is a need to provide proper standardized clinical nutrition services as a primary treatment and we observed large variations in the quality of nutritional service s in long term care hospitals. Therefore, government and local hospitals have to work on implementing nutritional programs and policies for improved service and care.

• Wind and Structures
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• 제27권6호
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• pp.357-368
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• 2018

For a long cable-stayed bridge, stay cables are its most important load-carrying components. In this paper, long-term monitoring of super-long stay cables of Sutong Bridge is introduced. A comprehensive data analysis procedure is presented, in which time domain and frequency domain based analyses are carried out. In time domain, the vibration data of several long stay cables are firstly analyzed and the standard deviation of the acceleration of stay cables, and its variation with time are obtained, as well as the relationship between in-plane vibration and out-plane vibration. Meanwhile, some vibrations such as wind and rain induced vibration are detected. Through frequency domain analysis, the basic frequencies of the stay cables are identified. Furthermore, the axial forces and their statistical parameters are acquired. To investigate the vibration deflection, an FFT-based decomposition method is used to get the modal deflection. In the end, the relationship between the vibration amplitude of stay cables and the wind speed is investigated based on correlation analysis. Through the adopted procedure, some structural parameters of the stay cables have been derived, which can be used for evaluating the component performance and corresponding management of stay cables.

• 한국노년학
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• 제30권1호
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• pp.81-91
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• 2010

본 연구는 노인의 인지능력을 기능적 관점에서 평가하기 위해 개발된 인지수행척도(Cognitive Performance Scale, CPS)가 우리나라 요양병원의 임상환경에 적합한지를 검증하기 위해 수행되었다. 이를 위해 CPS와 MMSE(Mini-Mental State Examination), GDS(Global Deterioration Scale)간의 수렴타당도, 조사자간 일치도, 내적 일관성을 측정하였다. 2개의 치매전문 요양병원 입원환자 393명을 대상으로 해당병원의 간호사가 표준화된 작성지침을 이용하여 CPS를 직접 측정하였고, 이 점수가 해당병원의 의사, 간호사가 측정한 GDS점수, 건강보험 청구 자료의 MMSE점수와 상관성이 있는지 분석하였다. 또한 동일 환자에 대해 또 한명의 간호사가 CPS를 한 번 더 측정하여 기존의 CPS점수와 비교하였다. 그 결과 CPS는 GDS와 중등도 이상의 상관관계(r=0.742, p<0.0001)를 보였고, MMSE와는 높은 상관관계(r=-0.794, p<0.0001)를 보였다. CPS의 Cronbach ${\alpha}$ 계수는 0.742로 높은 내적 일관성을 나타냈고 조사자간 일치도를 보기 위해 산출한 문항별 Kappa 계수는 0.772~1.000이었다. 우리나라 요양병원 환경에서도 노인의 인지능력을 기능적 관점에서 평가하기 위해 CPS를 사용하는 것이 타당하다고 판단된다.

• 한국직업건강간호학회지
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• 제25권2호
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• pp.118-129
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• 2016

Purpose: This study aims to examine the levels of the perception and work performance of patient safety based on the healthcare accreditation criteria among long-term care hospital nurses. Methods: A cross-sectional study was performed using questionnaires. Out of 205 criteria, 39 items relevant to patient safety were selectively adapted for this study. Data were analyzed with descriptive statistics, t-test, ANOVA, and Pearson correlation coefficient. Results: The mean scores of perception and work performance were 4.36 and 4.24 out of 5, respectively, and the difference between them was significantly different (t=5.78, p<.001). The two variables were both significantly higher among those nurses who were older, married, head nurses, had many nursing experiences, and aware of Healthcare Accreditation than the other nurses. Positive correlations were observed between perception and work performance in all three sub-systems. The relations between these two in the patient care system was the most highly correlated (r=.894, p<.001). The lowest scores of perception and work performances were fire-related criteria (i.e., reporting). Conclusion: Overall, subject's perception proves to be higher than their work performance. It is necessary to develop some viable environment and training programs to enhance their work performance up to the level of their perception of patient safety.