• 정보관리학회지
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• 제39권1호
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• pp.17-44
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• 2022

본 연구는 대학도서관 이용자의 도서관 불안 요인을 분석하여 비대면 서비스가 도서관 불안해소에 미치는 영향에 관한 방안 제시를 목적으로 하였다. 이를 위해 코로나19 사태에 따른 대학도서관의 이용자 서비스 대응 활동 사례를 살펴보고, 재학생 5,000명 이상 10,000명 이하의 국내 4년제 대학도서관에서 재학생 1인당 도서관 방문자수가 가장 높은 순위부터 40교를 선정하여 비대면 방식의 정보 서비스 및 프로그램 사례를 분석하였고, K대학도서관을 이용하는 재학생을 대상으로 K-LAS를 재구성하여 설문조사를 실시하였다. 수집된 데이터를 대상으로 빈도분석, 기술통계분석, 탐색적 요인분석, 신뢰도분석, 상관관계분석, 다중회귀분석을 적용하여 이용자의 도서관 불안 요인을 분석하였다. 도서관의 물리적·환경적 요인, 자료검색선정 요인, 디지털 정보시스템 요인, 사서(직원) 요인, 심리·정서적 요인등 5가지 도서관 불안 요인과 비대면 서비스 활성화 요인간 관계를 파악하고, 비대면 서비스 활성화 요인이 도서관 불안요인에 미치는 영향을 살펴보았으며, 그 결과, 비대면 서비스 활성화 요인들이 도서관 디지털 정보시스템 불안 요인에 가장 크게 영형을 끼치는 것으로 나타났다. 분석결과에 기초하여 비대면 서비스 활성화를 통하여 이용자의 도서관 불안해소 방안을 도출해보고자 하였다.

• Human Ecology Research
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• 제51권4호
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• pp.413-424
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• 2013

The purpose of this study is to examine the influence of social face sensitivity on vanity and consumption behavior. Questionnaires were administered to 461 college students living in Deagu Metropolitan City and Kyungbook province. Frequency, factor analysis, reliability analysis, regression analysis, and t-test were used for data analysis. Social face sensitivity was categorized into consciousness of being embarrassed, social formality, other consciousness and prestigiousness. Vanity factors were found as physical price, achievement concern, achievement price, and physical concern. Consumption behavior were categorized into 5 factors such as ostentatious consumption, impulsive buying, external information search, brand trust, utilization of internet information and material-oriented. Consciousness of being embarrassed, social formality, and other consciousness, the sub-variables of social face sensitivity had significant effects on achievement concerns and physical concerns. Other consciousness of social face sensitivity had significant effects on all factors of consumption behaviors. There was significant differences in the prestige of social face sensitivity and physical concerns of vanity and ostentatious consumption, impulsive buying, and also in external information search and utilization of internet information of consumer behavior. This indicates that women showed high physical concerns for vanity and ostentatious consumption, impulsive buying, external information search and utilization of internet information of consumption behavior while men care more about prestigiousness of social face sensitivity.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제12권3호
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• pp.250-255
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• 2012

Face recognition has wide applications in security and surveillance systems as well as in robot vision and machine interfaces. Conventional challenges in face recognition include pose, illumination, and expression, and face recognition at a distance involves additional challenges because long-distance images are often degraded due to poor focusing and motion blurring. This study investigates the effectiveness of applying photon-counting linear discriminant analysis (Pc-LDA) to face recognition in harsh environments. A related technique, Fisher linear discriminant analysis, has been found to be optimal, but it often suffers from the singularity problem because the number of available training images is generally much smaller than the number of pixels. Pc-LDA, on the other hand, realizes the Fisher criterion in high-dimensional space without any dimensionality reduction. Therefore, it provides more invariant solutions to image recognition under distortion and degradation. Two decision rules are employed: one is based on Euclidean distance; the other, on normalized correlation. In the experiments, the asymptotic equivalence of the photon-counting method to the Fisher method is verified with simulated data. Degraded facial images are employed to demonstrate the robustness of the photon-counting classifier in harsh environments. Four types of blurring point spread functions are applied to the test images in order to simulate long-distance acquisition. The results are compared with those of conventional Eigen face and Fisher face methods. The results indicate that Pc-LDA is better than conventional facial recognition techniques.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 봄 학술발표회 논문집
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• pp.457-464
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• 2000

Stereographic method is a general and basic method to analyse sliding failure potential of rock slope. Region of failure analysis using stereographic method extend to curved slope from straight slope in this paper, Curved slope is defined as the multi-face slope with free surface more than two face and has different characteristics from straight single face slope. Individual daylight envelopes of free surfaces are combined into total daylight envelope of multi-face slope. So, sliding envelope of multi-face slope is the daylight envelope except friction cone. Specially, If only single joint set is developed in the slope, single plane sliding(or plane failure) is impossible in the single-face straight slope, but possible in the multi-face slope. In the multi-face slope with only one joint set, single plane sliding occurs when orientation of sliding plane is between two side slope orientation in the sliding envelope.

• 대한토목학회논문집
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• 제26권5C호
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• pp.351-358
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• 2006

본 연구의 목적은 원심모형실험으로 담수에 따른 CFRD 차수벽의 거동을 모사하는 방법 및 절차를 제시하고, 실험결과로 부터 콘크리트차수벽의 휨강성이 차수벽의 변위에 미치는 영향을 살펴보고, 원심모형실험으로 검증된 수치해석을 통하여 차수벽지지죤 강성이 차수벽콘크리트의 변위와 모멘트에 미치는 영향을 평가하는 것이다. 이를 위하여 실제 운영 중인 D댐에 대해 차수벽의 강성을 2가지로 변화시킨 원심모형실험을 수행하였고, 모형체의 축조재료에 대한 삼축압축실험을 수행하고 그 결과를 입력치로 한 수치해석을 통해 원심모형실험을 모사하였다. 모사된 수치해석 결과를 실험결과와 비교하여 수치모형의 적정성을 확인하고 확인된 수치모형에 대해 지지죤 강성을 변화시킨 수치해석을 수행하여 지지죤 강성변화에 따른 콘크리트 차수벽의 연직변위 및 모멘트 발생 양상을 분석하였다. 차수벽 두께를 2가지로 달리한 원심모형실험 결과, CFRD 차수벽 변위는 차수 목적의 콘크리트 두께 범위 내에서는 두께의 영향이 거의 없는 것으로 나타났다. 원심모형실험과 수치해석 결과로부터 담수 시 CFRD 차수벽의 변위 및 최대변위 발생위치는 콘크리트차수벽 휨강성에는 영향이 거의 없고, 차수벽지지죤의 강성이 큰 영향을 주는 것으로 나타났다.

• 스마트미디어저널
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• 제5권1호
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• pp.24-29
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• 2016

높은 수준의 지능형 영상 감시 시스템을 만족하기 위해서는 단순히 객체를 검출해서 분류하는 것뿐만 아니라 대상에 대한 정확한 신원 정보까지 확인할 수 있어야 한다. 사람을 구별하는 대표적인 얼굴 인식은 얼굴 자체의 가변성뿐만 아니라 조명, 배경, 카메라의 각도와 같은 외적요인에 따라 인식률의 변화가 발생한다. 본 논문에서는 다양한 실험을 통해 거리 변화에 의한 얼굴 영상의 크기 변화에 강인한 얼굴 인식 방법을 분석한다. 얼굴 인식 실험은 1m~5m에서 추출한 실제 거리별 얼굴 영상으로 이루어졌다. 실험결과, 1인당 학습 영상의 수가 많을 경우는 얼굴 특징 추출 방법으로 LDA를 사용한 방법이 전체 평균 75.4%로 가장 우수한 성능을 나타냈다. 하지만 1인당 학습 영상의 수가 5장 이하가 될 때는 CNN을 사용한 방법이 69.8%로 가장 우수한 성능을 나타냈다. 또한, 저해상도 얼굴 인식의 경우 얼굴 영상의 크기가 $15{\times}15$보다 작아지면 인식률이 급격히 감소함을 확인했다.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제14권7호
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• pp.723-727
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• 2008

2D 기반의 얼굴 분석 및 처리 알고리즘은 포즈 및 조명에 강인하지 못한 문제점들이 존재한다. 이러한 이유로 과거 3D 기반의 얼굴 분석 및 처리 분야에 많은 연구를 진행하려 하였지만, 컴퓨팅 파워의 한계와 고속 스캐너의 부재 등으로 많은 연구가 진행되지 못하였다. 하지만 오늘날 하루가 다르게 빨라지고 있는 컴퓨터의 성능으로 인해 주춤했던 연구들이 다시 진행되고 있다. 이에 본 논문에서는 널리 알려진 선형 모델 기반의 3D morphable face model을 제작하고 성능을 높이는 방법에 대한 구현 및 dense correspondence 문제를 해결하기 위한 방법을 제안한다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2001년도 봄 학술발표회 논문집
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• pp.41-48
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• 2001

In this study, two factors are simultaneously considered for assessing tunnel face stability: one is the effective stress acting on the tunnel face calculated by upper bound solution; and the other is the seepage force calculated by numerical analysis under the condition of steady-state groundwater flow. The seepage forces calculated by numerical analysis are compared with the results of a model test. From the results of derivations of the upper bound solution with the consideration of seepage forces acting on the tunnel face, it could be found that the minimum support pressure for the face stability is equal to the sum of effective support pressure and seepage pressure acting on the tunnel face. Also it could be found that the average seepage pressure acting on the tunnel face is proportional to the hydrostatic pressure at the same elevation and the magnitude is about 22% of the hydrostatic pressure for the drainage type tunnel and about 28% for the water-proof type tunnel. The model tests performed with a tunnel model had a similar trend with the seepage pressure calculated by numerical analysis. From the model tests it could be also found that the collapse at the tunnel face occurs suddenly and leads to unlimited displacement.

• Geomechanics and Engineering
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• 제32권2호
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• pp.145-157
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• 2023

This paper aims at investigating the face stability of large-diameter underwater shield tunnels considering seepage in soft-hard uneven strata. Using the kinematic approach of limit upper-bound analysis, the analytical solution of limit supporting pressure on the tunnel face considering seepage was obtained based on a logarithmic spiral collapsed body in uneven strata. The stability analysis method of the excavation face with different soft- and hard-stratum ratios was explored and validated. Moreover, the effects of water level and burial depth on tunnel face stability were discussed. The results show the effect of seepage on the excavation face stability can be accounted as the seepage force on the excavation face and the seepage force of pore water in instability body. When the thickness ratio of hard soil layer within the excavation face exceeds 1/6D, the interface of the soft and hard soil layer can be placed at tunnel axis during stability analysis. The reliability of the analytical solution of the limit supporting pressure is validated by numerical method and literature methods. The increase of water level causes the instability of upper soft soil layer firstly due to the higher seepage force. With the rise of burial depth, the horizontal displacement of the upper soft soil decreases and the limit supporting pressure changes little because of soil arching effect.

• 한국임상보건과학회지
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• 제10권1호
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• pp.1543-1552
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• 2022

Purpose: It is intended to investigate the satisfaction of dental hygiene students with non-face-to-face online classes and use them as basic data for successful lecture design and operation. Methods: The data collected in this study were analyzed using the lBM SPSS Statistics 21 program. The general characteristics of the study subjects were frequency analysis, non-face-to-face online class satisfaction, and test satisfaction were frequency analysis and technical statistics. Through the independent sample T test, a t-test was conducted to find out whether there was an average difference in online class and test satisfaction according to grade. Results: The advantages of non-face-to-face online classes were that repetitive learning was possible (57.7%), the disadvantage was that there was a lack of real-time communication (74.9%), and the most efficient teaching method was a mixed form of online and face-to-face classes (64.9%). The satisfaction level of online classes was 2.69 points for 'self-directed learning habits,' which was the highest compared to the overall average of 2.55 points, and 2.09 points for 'difficulty in interaction between instructors and learners in online classes.'Non-face-to-face test satisfaction was 2.68 points for 'short test time gives fairness to test results,' higher than the overall average of 2.45 points, and 2.07 points for 'no difficulty accessing the test.'In terms of satisfaction with the non-face-to-face test according to the grade, it was found that the third grade showed a more negative attitude than the second grade in terms of sexual fairness (p<0.05). Conclusions: Through the above results, non-face-to-face online classes require various content development and some mixed classes considering the level of students, and instructors' efforts to improve the quality of classes for interaction between instructors and learners are needed.