• 한국음향학회지
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• 제34권4호
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• pp.321-327
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• 2015

본 연구에서는 음성인식기 성능향상을 위한 영상기반 음성구간 검출방법을 제안한다. 기존의 광류기반 방법은 조도변화에 대응하지 못하고 연산량이 많아서 이동형 플렛홈에 적용되는 스마트 기기에 적용하는데 어려움이 있고, 카오스 이론 기반 방법은 조도변화에 강인하지만 차량 움직임 및 입술 검출의 부정확성으로 인해 발생하는 오검출이 발생하는 문제점이 있다. 본 연구에서는 기존 영상기반 음성구간 검출 알고리즘의 문제점을 해결하기 위해 지역 분산 히스토그램(Local Variance Histogram, LVH)과 적응적 문턱값 추정 방법을 이용한 음성구간 검출 알고리즘을 제안한다. 제안된 방법은 조도 변화에 따른 픽셀 변화에 강인하고 연산속도가 빠르며 적응적 문턱값을 사용하여 조도변화 및 움직임이 큰 차량 운전자의 발화를 강인하게 검출할 수 있다. 이동중인 차량에서 촬영한 운전자의 동영상을 이용하여 성능을 측정한 결과 제안한 방법이 기존의 방법에 비하여 성능이 우수함을 확인하였다.

• 물과 미래
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• 제27권3호
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• pp.45-54
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• 1994

물수지 모델을 사용하여 발생시킨 시계열에 대해서 프랙탈(Fractal) 차원의 기본 이론이 소개 및 적용되었고 물수지 방정식이 넓은 지역에 대해 계절 시간 규모로 분석하였다. 중간 규모 순환의 발생과 변화에 있어 강우의 국부 재순환과 토양 수분의 동력학적 영향이 명시적으로 포함되어 있고 지체 시간 또한 분석에서 고려되었다. 시스템은 전개에 있어 변수 값들에 따라 고정점, 한계주기 그리고 카오스(Chaos)적인 행태와 같은 서로 다른 결과를 보여 주었다. 발생된 시계열의 추계학적인 행태는 궤적들이 초기 조거넹 매우 민감한 한정된 수의 방정식을 가지는 비선형 동력학 시스템으로부터 발생하는 확정론적 카오스 때문이다. 강우의 특성으로부터 발생하는 잡음은 어트랙터(Attractor)의 조직화된 구조를 파괴시키는데, 잡음의 존재에도 불구하고 어트랙터가 존재한다는 것은 시스템의 전개의 다기 예측에 있어 매우 중요하다고 할 수가 있다. 이러한 비선형 동력계가 가지고 있는 의미는 수문자료나 현상들의 해석과 모델링에 있어 중요하다.

• 대한한의진단학회지
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• 제11권2호
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• pp.96-115
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• 2007

Background and Purpose: Electroencephalogram(EEG) is a multi-scaled signal consisting of several components of time series with different origins. Recently, because of the absence of an identified metric which quantifies the complex amount of information, there are many limitations in using such a linear method. According to chaos theory, irregular signals of EEG can also result from low dimensional deterministic chaos. Chaotic nonlinear dynamics in the EEG can be studied by calculating the correlation dimension. The aim of this study is to analyze correlation between the correlation dimension of EEG and psychological Test (TCI). Methods: Before and after moxibustion treatment, EEG raw data were measured by moving windows during 15 minutes. The correlation dimension(D2) was calculated from stabilized 40 seconds in 15 minutes data. 8 channels EEG study on the Fp, F, T, P was carried out in 30 subjects. Results: Correlation analysis of TCI test is calculated with deterministic non-linear data and stochastic non-linear data. 1. Novelty seeking in temperament is positive correlated with D2 of EEG on Fp. 2. reward dependence in temperament is positive correlated with D2 of EEG on T3,T4 and negative correlated with D2 of EEG on P3,P4. 3. self directedness in character is positive correlated with D2 of EEG on F4, P3. 4. Harm avoidance is negative correlated with D2 of EEG on Fp2, T3, P3. Conclusion: These results suggest that nonlinear analysis of EEG can quantify dynamic state of brain abolut psychological Test (TCI).

• 정보보호학회논문지
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• 제14권4호
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• pp.183-194
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• 2004

인터넷 이용의 폭발적인 증가와 유무선 통신기술의 발달로 인해 디지털 영상의 교환이 매우 빈번하게 일어나고 있는 현실에서 개인 사생활과 기업 및 기관의 기밀에 관련된 영상에 대한 보안이 매우 중요시 되어가고 있다. 또한 최근 카오스 이론과 암호와의 밀접한 관련성으로 인해 카오스 사상(Map)에 기반 한 새로운 암호기술 개발에 많은 연구가 진행되고 있다. 본 논문에서는 1차원 카오스 사상(Map)인 PLCM(Piecewise Linear Chaotic Map)과 2차원 카오스 사상인 Baker 사상을 이용한 정지영상 암호 시스템을 제안한다. 본 제안 시스템은 1차원 PLCM을 기반으로 한 섭동(Perturbance)기반 카오스 스트림(Stream)암호 기법과 2차원 Baker 사상을 기반으로 한 카오스 블록(Block)암호 기법이 결합된 구조로서 좋은 혼동(Confusion)특성과 확산(Diffusion)특성을 지닌 매우 안전하고 구현이 쉬운 암호시스템이다. 또한 본 논문에서는 실험 결과를 통해 통계적(Statistical) 공격에도 매우 강함을 보여주었다.

• 부모자녀건강학회지
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• 제7권1호
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• pp.61-72
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• 2004

This study investigates the history and principles of Korean traditional Taekyo by literary research. Taekyo is compared with prenatal care of modern western medicine, and its principles turn out to be just as scientific. Suggestions are made for a nurse to apply Taekyo principles to nursing care. Traditional Taekyo is an antenatal training which emphasizes how an expectant mother should carry herself (behavior) and a frame of mind she should have (her attitude) in order to produce a child with sound mind and body, as well as good personality. Though Taekyo has been originated in China 2,800 years ago, it has been recorded comprehensively in Korea in a series of publications such as Taekyoshingi, and Kyuhapchongseo, and passed on in a various verbal transitions like Samtaedo, Oliltaedo, etc. Taekyo principles can be explained by yin and yang theory, quantum theory, chaos theory, fetal programming, and social support theory. Some part of Taekyo shares the same scientific ground with prenatal care advocated by modern nursing care for women, where it emphasizes the role of a father, and participation of the whole family in helping an expectant mother. Applying Taekyo principles to nursing care is being done through Taekyo programs, which combine traditional Taekyo with modern prenatal care, in classes for child birth and many pregnant women participate. On the other hand, some internet Taekyo programs appear to be rather distorted and overzealous. A nurse has a responsibility to present a guideline and to monitor internet sites, so that pregnant women can understand the correct concept of traditional Taekyo before they practice it.

• 동양고전연구
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• 제35호
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• pp.135-159
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• 2009

무신란(武臣亂) 이후 고려 말에 이르는 시대상황은 대내외적으로 위기가 점증되는 시대이다. 정치기강의 문란, 사회윤리의 이완, 사상계의 침체 그리고 중국에서의 원나라의 쇠퇴와 명나라의 발흥 등 14세기 후반은 긴장과 혼란이 연속되는 상황이었다. 이러한 시대에 삶을 영위한 야은(壄隱) 전녹생(田祿生)의 의리사상과 경세론을 탐구하려는 것이 본 논문의 목적이다. 원명교체기에 처하여 국권이 위협당하였던 고려의 상황 아래에서 전녹생의 의리사상은 '배원친명론'으로 표현되었으며, 그것은 국가의 안위(安危)를 문제삼고 고려 한 나라의 주권을 회복한다는 차원에서 제기된 것이었다. 전녹생은 백성을 편안하게 다스리려면 일을 꾸미거나 번잡하게 만들지 말고 생업에 전념할 수 있게 하는 것이라고 보았다. 전녹생은 당시의 시대여건이 마치 실타래와 같아서 급하게 서둘수록 저절로 꼬이기 쉬우니 아주 조금이라도 백성들을 괴롭히지 말고 차분하게 민생안정을 도모할 것을 강조하였다.

• 대한간호학회지
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• 제51권6호
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• pp.689-702
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• 2021

Purpose: This study aimed to develop a situation-specific theory to explain nurses' experiences of the COVID-19 crisis. Methods: The participants were 16 hospital nurses who experienced the COVID-19 crisis. Data were collected through in-depth individual interviews from September 2, 2020 to January 20, 2021. Transcribed interview contents were analyzed using Corbin and Strauss's grounded theory method. Results: A total of 38 concepts and 13 categories were identified through an open coding process. The core category found was becoming a pioneering nurse who turns crises into opportunities. The causal conditions were the chaos of being exposed defenselessly to an unexpected pandemic, fear caused by a nursing care field reminiscent of a battlefield, and moral distress from failing to protect patients' human dignity. The contextual conditions were feeling like the scapegoat of the hospital organization, increasing uncertainty due to the unpredictable state of COVID-19, and relative deprivation due to inappropriate treatment. The central phenomenon was suffering alone while experiencing the dedication of the COVID-19 hero image. The action/interactional strategy were efforts to find a breakthrough and getting the nurse's mind right, and the intervening conditions were gratitude for those who care for broken hearts and getting used to myself with repetitive work. The Consequences were becoming an independent nurse and frustration with the unchanging reality. Conclusion: This study provides the foundation for the nurse's situation-specific theory of the COVID-19 crisis by defining the crisis perceived by nurses who cared for COVID-19 patients and suggesting types of coping with the crisis.

• Structural Engineering and Mechanics
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• 제9권4호
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• pp.397-416
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• 2000

The present study deals with the nonlinear dynamics and stability of autonomous dissipative either imperfect potential (limit point) systems or perfect (bifurcational) non-potential ones. Through a fully nonlinear dynamic analysis, performed on two simple 2-DOF models corresponding to the classes of systems mentioned above, and with the aid of basic definitions of the theory of nonlinear dynamical systems, new important phenomena are revealed. For the first class of systems a third possibility of postbuckling dynamic response is offered, associated with a point attractor on the prebuckling primary path, while for the second one the new findings are chaos-like (most likely chaotic) motions, consecutive regions of point and periodic attractors, series of global bifurcations and point attractor response of always existing complementary equilibrium configurations, regardless of the value of the nonconservativeness parameter.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권8호
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• pp.2833-2850
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• 2014

This paper proposes a novel framework for traffic video classification based on chaotic features. First, each pixel intensity series in the video is modeled as a time series. Second, the chaos theory is employed to generate chaotic features. Each video is then represented by a feature vector matrix. Third, the mean shift clustering algorithm is used to cluster the feature vectors. Finally, the earth mover's distance (EMD) is employed to obtain a distance matrix by comparing the similarity based on the segmentation results. The distance matrix is transformed into a matching matrix, which is evaluated in the classification task. Experimental results show good traffic video classification performance, with robustness to environmental conditions, such as occlusions and variable lighting.

• 대한간호학회지
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• 제36권1호
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• pp.25-36
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• 2006

Purpose: The purpose of the study was to identify the adaptation process to problem based learning(PBL) among nursing students who have experienced PBL classes for two years. Method: Data was collected from 11 nursing students with in-depth interviews and direct observation of their PBL experiences by a researcher who has been a facilitator for PBL class for 3years. Immediately after the interviews all of them were transcribed. It was analyzed by the Ground theory of Corbin and Strauss. Results: A derived core category was 'Acquiring PBL'. 4 stages of the acquiring process were derived and written in time sequence: chaos, confusion, beginning insight, and achievement stage. Conclusion: The results will not only expand understanding of the students for the facilitator and school which has adopted PBL but also provide information to develop an orientation program for PBL. Further research on the facilitator's role experiences is recommended.