• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 센서 박막재료 반도체 세라믹
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• pp.178-181
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• 2003

In this work, we etched PZT films with various additive gases ($O_2$ and Ar) in $Cl_2/CF_4$ plasmas, while mixing ratio was fixed at 8/2. After the etching, the plasma induced damages are characterized in terms of hysteresis curves, leakage current, retention properties, and switching polarization. When the electrical properties of PZT etched in $O_2$ or Ar added $Cl_2/CF_4$ were compared, the value of remanent polarization in $O_2$ added $Cl_2/CF_4$ plasma is higher than that in Ar. added plasma. The maximum etch rate of the PZT thin films was 145 nm/min for 30% Ar added $Cl_2/CF_4$ gas having mixing ratio of 8/2 and 110 nm/min for 10% $O_2$ added to that same gas mixture. In order to recover the ferroelectic properties of the PZT thin films after etching, we annealed the etched PZT thin films at $550^{\circ}C$ in an $O_2$ atmosphere for 10 min. From the hysteresis curves, leakage current, retention property and switching polarization, the reduction of the etching damage and the recovery via the annealing was turned out to be more effective when $O_2$ was added to $Cl_2/CF_4$ than Ar. X-ray diffraction (XRD) showed that the structural damage was lower when $O_2$ was added to $Cl_2/CF_4$. And the improvement in the ferroelectric properties of the annealed samples was consistent with the increased intensities of the (100) and the (200) PZT peaks.

• 한국정보통신학회논문지
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• 제19권9호
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• pp.2029-2036
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• 2015

하둡 MR(MapReduce)는 매퍼(Mapper)의 출력을 리듀서(Reducer)의 입력으로 전달하기 위해 파티션 함수(Partition Function)을 사용한다. 파티션 함수는 키에서 해쉬 값을 계산한 후 리듀서 개수로 나머지 연산을 수행하여 대상 리듀서를 결정한다. 기존 파티션 함수는 키의 편중도에 민감하여 잡이 균등하게 배분될 수 없었다. 잡이 균등하게 배분되지 못하면 특정 리듀서들의 처리 수행 시간이 길어져 전체 분산 처리 수행 성능에 영향을 주게 된다. 이에 본 논문은 VPT(Virtual Partition Table)을 제안하고 편중도가 심한 데이터에 VPT을 적용하여 실험을 수행 하였다. 적용된 VPT는 기존 파티션 함수와 대비하여 평균 3초 정도 성능향상이 발생하였으며, 데이터 처리량이 증가할수록 성능 향상 폭이 증가할 것으로 예상된다.

• 한국통신학회논문지
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• 제29권11C호
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• pp.1498-1509
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• 2004

본 논문에서는 향후 유비쿼터스 센서 네트워크 응용 등에 적합하도록 간단한 송수신기 구조를 유지하면서, 실제 데이터를 전송하기 전에 Noise Power Calibration 및 Noise Power Windowing 방법을 통해 잡음의 영향을 고려하여 적응적인 임계값을 결정하고 이를 이용하여 전력검출 (Power Detection)을 수행하여 성능을 향상하는 임펄스 라디오 (Impulse Radio) 형태의 Noncoherent OOK (On-Off Keying) UWB (Ultra Wide Band) 시스템을 제시하고, 전형적인 UWB 실내 무선 채널 모델에서의 성능을 분석하였다. 모의실험 결과 AWGN (Additive White Gaussian Noise) 채널에서는 Noise Power Calibration 모드를 위한 슬롯수의 증가에 따라 이상적인 Ideal Adaptive Threshold를 사용하는 경우께 근접하는 우수한 성능을 보임을 확인할 수 있었고, 반면 데이터 전송률의 큰 감소를 감수해야 하는 Noise Power Windowing 방법에 의한 성능 개선은 두드러지게 나타나지 않음을 알 수 있었다. 더욱이 IEEE 802.15 Task Group 3a UWB 실내 채널 모델을 이용한 모의실험 결과, Noise Power Calibration 모드가 적용된 Noncoherent OOK UWB 시스템의 성능이 Ideal Adaptive Threshold의 경우와 비트오율 성능이 매우 근접하며, 펄스 반복 전송의 회수의 증가에 따라 비트오율 성능이 향상됨을 확인 할 수 있었다.

• 한국작물학회지
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• 제64권4호
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• pp.432-440
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• 2019

Global climate change exerts adverse effects on maize production. Among abiotic stresses, drought stress during the tasseling stage (VT) can increase anthesis-silking intervals (ASI) and decrease yield. We performed an evaluation of ASI and yield using a drought-sensitive line (Ki3) and a drought-tolerant line (Ki11) to analyze the correlation with ASI and yield. Moreover, the de novo data of Ki11 were analyzed to find putative novel transcripts related todrought stress in tropical maize. A total of 182 transcripts, with a log2 ratio >1.5, were found by comparing drought conditions to a control. The top 40 transcripts of high expression levels in the de novo analysis were selected and analyzed with PCR. Of the 40 transcripts, six novel transcripts were detected by quantitative real-time PCR (qRT-PCR) using seedling and VT stage samples. Five transcripts (transcripts_1, 12, 34, 35, and 40) were up-regulated in the Ki11 shoot at seedling stage, and transcripts_1, 12, and 40 were up-regulated at the re-watering stage after 12 h of drought stress. The transcripts_32 and 34 were up-regulated at the VT stage. Hence, transcript_34 possibly plays a significant role in drought tolerance during the seedling and VT stages. The transcript_32 was identified as chloramphenicol acetyltransferase (CAT) by Pfam domain analysis. The function of the other transcripts remained unknown. Further characterization of these novel transcripts in genetic regulation will be of great value for the improvement of maize production.

• 디자인학연구
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• 제18권3호
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• pp.149-160
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• 2005

본 연구는 e-러닝 환경에서 자기주도적 교수학습전략을 바탕으로 학습자의 상호작용성과 상용편이성을 고려한 자기주도 학습운영시스템과 학습컨텐츠를 구현한 것이다. 상호작용유형은 학습자를 중심으로 (1) 학습자와 교수자 (2) 학습자와 학습자 (3) 학습자와 학습컨텐츠 (4) 학습자와 학습운영시스템으로 나눈다. 학습운영시스템은 학습자들의 자기 주도적 학습 능력을 향상시키고 온라인 커뮤니케이션이 촉진될 수 있도록 유형에 따라 상호작용 설계전략을 제시하고 구체적인 구성요소들을 설정하여 구현한다. 학습컨텐츠는 자기주도적 학습전략을 기초로 단순한 네비게이션, 일관성, 직관적인 인터페이스, 연결성, 사용자 지원, 즉각적 피드백이라는 여섯 가지 인터페이스 전략을 기초로 학습자의 사용편이성을 최대한 고려하여 구현한다. 본 연구개발은 학습운영시스템의 자기 주도적 기능을 보완하고 그러한 기능들을 학습컨텐츠와 연결함으로써 학습자 중심의 상호작용성과 사용편이성을 개선한 것에 의의가 있다. 본 연구결과는 e-러닝 학습 환경의 질 개선에 도움이 될 것으로 기대된다.

• 대한의용생체공학회:의공학회지
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• 제40권6호
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• pp.242-249
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• 2019

Forearm electromyography (EMG) generated by wrist movements has been widely used to develop an electrical prosthetic hand, but EMG generated by finger movements has been rarely used even though 20% of amputees lose fingers. The goal of this study is to improve the classification performance of different finger movements using a deep learning algorithm, and thereby contributing to the development of a high-performance finger-based prosthetic hand. Ten participants took part in this study, and they performed seven different finger movements forty times each (thumb, index, middle, ring, little, fist and rest) during which EMG was measured from the back of the right hand using four bipolar electrodes. We extracted mean absolute value (MAV), root mean square (RMS), and mean (MEAN) from the measured EMGs for each trial as features, and a 5x5-fold cross-validation was performed to estimate the classification performance of seven different finger movements. A long short-term memory (LSTM) model was used as a classifier, and linear discriminant analysis (LDA) that is a widely used classifier in previous studies was also used for comparison. The best performance of the LSTM model (sensitivity: 91.46 ± 6.72%; specificity: 91.27 ± 4.18%; accuracy: 91.26 ± 4.09%) significantly outperformed that of LDA (sensitivity: 84.55 ± 9.61%; specificity: 84.02 ± 6.00%; accuracy: 84.00 ± 5.87%). Our result demonstrates the feasibility of a deep learning algorithm (LSTM) to improve the performance of classifying different finger movements using EMG.

• 한국의료질향상학회지
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• 제23권2호
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• pp.37-54
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• 2017

Objectives: The purpose of this preliminary study was to identify the nurses' perception regarding disclosure of patient safety incidents (DPSI) and to evaluate the effectiveness of education for DPSI. Methods: DPSI education was conducted for nurses majoring in clinical nurse specialist at an university. Before and after the education, the nurses made a questionnaire to evaluate the perception of DPSI. The questionnaires were divided into four categories: first, overall perception of the DPSI; second, recognition evaluation of the DPSI using hypothetical case, third, opinion on legal and nonlegal measures for facilitating the DPSI; and fourth, socio-demographic factors. The Wilcoxon signed rank test was performed on the DPSI questionnaire response to compare the perceptions before and after the education. Results: A total of 10 nurses participated in the education. DPSI education showed the possibility of improving the overall perception, necessity, effect, obstacle, and promotion method of DPSI, although there were also several responses where there was no statistical significance. In particular, DPSI education led to statistically significance change in the perception of obstacles for DPSI. For example, the number of respondents who agreed to the item "DPSI will increase the incidence of medical lawsuits." was 7 before education but decreased to 3 after education (P-value: .025) Furthermore, nurses' perception of DPSI from this study was generally positive regardless of education. Conclusion:In the future, it will be necessary to carry out DPSI education and training and to evaluate its effectiveness for more nurses.

• 대한한방피부미용학회지
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• 제1권1호
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• pp.98-113
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• 2005

This paper provides comparison and analysis between brand images of Korean herbal cosmetics and general, imported cosmetic brands, focusing on product's symbolic and functional images. The objective is to evaluate brand images of Korean herbal cosmetics to suggest a powerful brand image strategy that will be different and competitive. Data collection was performed on 300 adult women who were over 20 years of age and lived in Seoul or KyongKi area. Analysis was carried out using SPSS version 11.5 and frequency analysis, T-Test and $X^2$ verification was also performed. Analysis results for brand images of Korean herbal cosmetics are as follows. First, satisfaction scale as a purchase feature for users of Korean herbal cosmetics were 'Normal' 51.5%, 'Satisfactory' 35.1%, 'Very Satisfactory' 8.2% and 'Unsatisfactory' 5.2%. Regarding improvements, 'Efficacy, Effect' was the highest with 46%. Second, 'SEOLHWASOO' and 'BAEKOKSENG' among Korean herbal cosmetic brands, 'IOPE' and 'ISA KNOX' among general cosmetic brands and 'LANCOME' and 'CHANEL' among imported cosmetic brands displayed high recognition. Third, the symbolic and functional images of Korean herbal cosmetic brands were seen to be better compared to their general and imported counterparts. Especially, product related features of Korean herbal cosmetic brands received a more positive response compared to imported brands, which suggests that with research and improvement regarding non-product related features, functional images of herbal brands may be appraised ahead of imported brands. Fourth, there is a significant difference in brand preference according to the satisfaction of groups who actually use herbal cosmetics and the purchasing attitudes of groups who do not. Therefore, an active relationship marketing strategy is required to maximize satisfaction and to elicit favorable attitudes. By developing functional native ingredients, constructing data that can prove its efficacy and effects, and appealing its unique, differentiated symbolic value together with Orientalism, herbal medicines will be able to take off to be acknowledged worldwide.

• Applied Biological Chemistry
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• 제37권5호
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• pp.320-325
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• 1994

볏짚의 사료가치를 증진시키기 위하여 알카리성 과산화수소를 이용하여 볏짚에 대한 처리수준별 화학성분의 변화와 in vitro 소화율을 조사 검토하였다. $H_2O_2(pH 11.5)$의 처리농도를 증가시킬수록 neutral detergent fiber(NDF), acid detergent fiber(ADF), hemicellulose, cellulose 및 lignin이 감소하였으며 $H_2O_2(pH 11.5)$를 처리한 후 수세시는 농도가 증가할수록 NDF, hemicellulose 및 lignin은 감소한 반면 ADF, cellulose, 회분은 증가하였다. 알카리성 과산화수소의 농도를 4%로 조정하여 처리하였을 때 pH는 $11.5{\sim}12.5$에서, 온도는 $55^{\circ}C$에서 세포벽구성물질의 분해에 효과적이었으며, 4% $H_2O_2(pH 11.5)$ 처리시 볏짚의 크기가 작을수록 잔류건물 중, hemicellulose, cellulose 및 lignin이 감소하였다. 알카리성 과산화수소의 처리에 의한 in vitro 소화율은 처리농도 및 pH가 증가할수록 볏짚의 크기가 작을수록 증가하였다.

• 한국농공학회논문집
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• 제60권5호
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• pp.125-134
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• 2018

Recently, interest in alternative energy has been increasing to reduce greenhouse gas emissions and fossil fuel consumption in accordance with the United Nations Framework Convention on Climate Change(UNFCCC). Accordingly, there is a need to use waste heat that unused throughout industrial systems for lowering the concentration of energy on fossil fuels. In particular, government support projects for the energy recycling of agriculture and fisheries such as cultivation of tropical crops and aquaculture are being actively carried out by utilizing waste heat and thermal effluents caused from large-scale industrial complexes including power plants. The study was conducted on supplier (power plant), consumer (farmer) and stakeholders (constructor and local governments) of domestic demonstration areas using waste heat that is abandoned from the power plant in the form of thermal effluents. It investigated the overall improvement and feasibility of government funded projects through field interviews and questionnaire-type surveys. The results of this study are expected to provide basic directions for the operation of the project in terms of nationwide expansion and diffusion of the heat source supply project at horticultural greenhouse by utilizing the thermal effluents from power plant.