• Proceedings of the Korea Inteligent Information System Society Conference
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• 1999.03a
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• pp.415-421
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• 1999

Altman의 연구(1965, 1977)나 Beaver의 연구(1986)와 같은 전통적 예측모형은 분석자의 판단에 따른 예측도가 높은 재무비율을 선정하여 다변량판별분석(MDA:multiple discriminant analysis), 로지스틱회귀분석 등과 같은 통계기법을 주로 이용해 왔으나 1980년 후반부터 인공지능 기법인 귀납적 학습방법, 인공신경망모형, 유전모형 등이 부실기업예측에 응용되기 시작했다. 최근 연구에서는 인공신경망을 활용한 변수 및 모형개발에 관한 보고가 있다. 그러나 지금까지의 연구가 주로 기업의 재무적 비율지표를 고려한 모형에 치중되었으며 정성적 자료인 비재무지표에 대한 검증과 선정이 자의적으로 이루어져온 경향이었다. 또한 너무 많은 입력변수를 사용할 경우 다중공선성 문제를 유발시킬 위험을 내포하고 있다. 본 연구에서는 부실기업예측모형을 수립하기 위하여 정량적 요인인 재무적 지표변수와 정성적 요인인 비재무적 지표변수를 모두 고려하였다. 재무적 지표변수는 상관분석 및 요인분석들을 통하여 유의한 변수들을 도출하였으며 비재무적 지표변수는 조직생태학내에서의 조직군내 조직사멸과 관련된 생태적 과정에 대한 요인들 중 조직군 내적요인으로 조직의 연령, 조직의 규모, 조직의 산업밀도를 도출하여 4개의 실험집단으로 분류하여 비재무적 지표변수를 보완하였다. 인공신경망은 다층퍼셉트론(multi-layer perceptrons)과 역방향 학습(back-propagation)알고리듬으로 입력변수와 출력변수, 그리고 하나의 은닉층을 가지는 3층 퍼셉트론(three layer perceptron)을 사용하였으며 은닉층의 노드(node)수는 3개를 사용하였다. 입력변수로 안정성, 활동성, 수익성, 성장성을 나타내는 재무적 지표변수와 조직규모, 조직연령, 그 조직이 속한 산업의 밀도를 비재무적 지표변수로 산정하여 로지스틱회귀 분석과 인공신경망 기법으로 검증하였다. 로지스틱회귀분석 결과에서는 재무적 지표변수 모형의 전체적 예측적중률이 87.50%인 반면에 재무/비재무적 지표모형은 90.18%로서 비재무적 지표변수 사용에 대한 개선의 효과가 나타났다. 표본기업들을 훈련과 시험용으로 구분하여 분석한 결과는 전체적으로 재무/비재무적 지표를 고려한 인공신경망기법의 예측적중률이 높은 것으로 나타났다. 즉, 로지스틱회귀 분석의 재무적 지표모형은 훈련, 시험용이 84.45%, 85.10%인 반면, 재무/비재무적 지표모형은 84.45%, 85.08%로서 거의 동일한 예측적중률을 가졌으나 인공신경망기법 분석에서는 재무적 지표모형이 92.23%, 85.10%인 반면, 재무/비재무적 지표모형에서는 91.12%, 88.06%로서 향상된 예측적중률을 나타내었다.

• Journal of the Korean Geophysical Society
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• v.6 no.3
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• pp.179-188
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• 2003

The object of grounding of electrical facility is to protect human and machine damage from the power supply interruption high voltage by use of the accident current dissipating into the ground. Generally, it is not easy to make suitable ground design for inhomogeneous subsurface geology and the variability of accident current in magnitude and duration time. To make efficient ground, ground potential rise must be controlled in the way of overall lowering and evenness. This study shows the case of optimized ground design by use of subsurface resistivity structure from electrical soundings.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.883-887
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• 2004

현재 전국적으로 $\blacktriangle$ 전기, 가스, 상수도, 하수도, 열수송관 등을 공동 수용하는 '지하공동구'가 14개 도시 30개소에 160.4km $\blacktriangle$ 보행공간으로 병용되는 '지하도로'가 23개도시 118개소에 63만 $m^2$ $\blacktriangle$ 지하도로내 설치된 지하점포가 1만1천798개소 23만$m^2$이 있다. 이와 같이 현대 도시내에서 지상공간의 과밀도 개발로 인하여 지하공간의 수요가 증대되어 지하공간 구조물이 많이 설치되고 있는 반면, 지하상가, 지하천 등과 같은 지하공간 시설에서 발생할 수 있는 침수피해 대책이 미흡한 실정이다. 본 연구에서는 과거 지하공간의 침수피해 실태를 조사하고 그 사례에서 원인을 분석하여 기술적 해결책을 도출해 내며, 침수방지를 위한 대책으로 국내에서 사용하고 있는 기숙이나 국외(미국, 일본)의 침수방지 기술 및 대책, 침수시 가이드라인 등을 조사하였다. 또한 지하공간이 침수되었을 때 일어날 수 있는 위험성에 대하여 이론적인, 기술적인 조건에 대하여 조사하였다. 이를 토대로 지하공간의 유형 즉, 지하주택, 지하상가, 지하공공시설(지하차도, 지하철, 전철, 지하변전소)에 대한 구체적인 침수방지 기숙에 대한 기준을 제시함으로써 궁극적으로는 지방자치단체, 관련기관, 연구기관에서 지하공간 침수방지대책에 대한 기초자료로 활용할 수 있을 것으로 판단된다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.10
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• pp.887-895
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• 2014

Drowsy driving is a large proportion of the total car accidents. For this reason, drowsiness detection and warning system for drivers has recently become a very important issue. Monitoring physiological signals provides the possibility of detecting features of drowsiness and fatigue of drivers. Many researches have been published that to measure electroencephalogram(EEG) signals is the effective way in order to be aware of fatigue and drowsiness of drivers. The aim of this study is to extract drowsiness-related features from a set of EEG signals and to classify the features into three states: alertness, transition, and drowsiness. This paper proposes a drowsiness detection system using errors-in-variables(EIV) for extraction of feature vectors and multilayer perceptron (MLP) for classification. The proposed method evaluates robustness for noise and compares to the previous one using linear predictive coding (LPC) combined with MLP. From evaluation results, we conclude that the proposed scheme outperforms the previous one in the low signal-to-noise ratio regime.

• Cross-Cultural Studies
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• v.51
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• pp.45-71
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• 2018

This essay explores Louise Erdrich's politically resistant voice which interrogates and disrupts the long-lasting, pernicious misbelief about Native Americans as 'vanishing people'. This essay chiefly focuses on the two female characters-Lulu Nanapush and Marie Lazarre Kashpaw-in the author's widely acclaimed novel Love Medicine (1993). First, illustrating the Chippewas' multifaceted resistances against white Americans' colonialist dominance disclosed in their enforcement of governmental policy, law, religion, and culture, this essay investigates how Erdrich does not stop telling her story that the idea of 'vanishing people'-another version of 'Manifest Destiny'-is unfounded. Second, by referring to Freud's and Marcuse's speculation on 'Eros'-the great unifying energy that preserves all life-as an alternative to the predicament caused by an oppressive civilization, this essay illuminates Erdrich's vision of sustaining and regenerating the Chippewas' tribal life and heritage that center on the embracing power of love reified in Lulu and Marie. Their undying energy consolidating their communal love and ties, despite the destructive, oppressive colonialist milieu inflicted on the Chippewa Indian reservation, sheds light on the author's politics of 'Eros' predicated tightly upon her historical consciousness.

• Korean Journal of School Psychology
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• v.18 no.2
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• pp.249-267
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• 2021

This study examined how social withdrawal as an individual factor and discrimination as a contextual factor contributed to depression caused by peer victimization among middle school students. Self-reported data of 1,611 students from 86 classrooms in 7 middle schools was analyzed, using multilevel path analysis. The results indicate that peer victimization had a significant partial mediating effect on the relation between social withdrawal and depression at the individual level. Social withdrawal had a direct positive effect on depression as well as an indirect positive effect on depression via high levels of peer victimization. Discrimination also positively predicted peer victimization at the classroom level. Moreover, classroom-level discrimination moderated the individual-level relations between social withdrawal and peer victimization. The relation between social withdrawal and peer victimization was much stronger as the levels of discrimination in the classroom were higher. These findings shed light on the importance of considering both individual and contextual factors when intervening to prevent peer victimization.

• Korean Journal of Family Social Work
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• no.57
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• pp.183-215
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• 2017

This study analyzes Korean childcare policy from a caring democracy perspective by using the normative policy analysis method. In the midst of emergent new social risks engendered by low fertility and aging population, feminist scholars proposed a transformative paradigm shift from economic growth to caring oriented development on a macro scale but researches on how this grand principle can be reflected into each policy have hardly been discussed. Thus, this study intends to contribute to such policy-driven discussion by analysing childcare policy on the basis of three normative values of freedom, equality and justice re-interpreted by caring democracy theory. Following are key findings. First, childcare policy does not guarantee public value and social solidarity due to the limitations of free choice from the perspective of freedom. Secondly, gender and class stratification has been worsened in a multiple and more complicated way by adding generational and racial dimensions to the existing gender inequality and vicious circulation of private care is observed from equality perspective. Thirdly, structural inequality aggravated injustice previously accumulated in the past rather than providing flat ground by adjustment.

• Fire Science and Engineering
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• v.24 no.6
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• pp.1-6
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• 2010

A smoldering ground fire can be a probable cause of reignition of surface fire when transmitted from Fermentation layer to Humus layer with temperature higher than that of ignition. Purpose of this paper is to identify experimental methodology on the potential risk of a smoldering ground fire, which is similar to the real surface fuel bed, and its combustion characteristics. The fuel model designed in this study is composed of 3 layers such as Litter layer, Fermentation layer and Humus layer and 8 Thermocouples are set through 3 layer at each boundary and in between to detect the temperature change and duration of smoldering and propagation velocity. As a result, it was observed that ignition conditions in the boundary between L layer and F layer determined transmission and non-transmisstion to F-H layer. In addition, range of critical humidity at which a smoldering ground fire was transmitted in a material layer was 33~44% and when temperature exceeds $350^{\circ}C$, likelihood of transmission of a smoldering ground fire was high. In the research, the experimental model for multi-layer smoldering ground fire is suggested and information about propagation of smoldering fire, possibility of reignition according to moisture content, propagation velocity and temperature change are obtained, Also, the built-up methods were established to help analyze basic characteristics of smoldering ground fire.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.27 no.3
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• pp.149-158
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• 2021

Advances in food packaging play an important role in keeping food manufacturing and food supply safe. Food packaging facilitates the storage, handling, transportation and preservation of food, and also contributes to the minimization of food waste. On the other hand, food packaging materials have high production volumes, short usage times, and accelerate the occurrence of environmental problems related to waste. The circular economy has already been introduced to pursue sustainability through resource conservation and recycling, and to reduce waste and carbon emissions. By activating an eco-friendly economic system that minimizes resource depletion and environmental pollution, reducing, reusing, recycling and redesigning the goals of the circular economy will reduce the impact of food packaging on the environment. This review focused on the safety aspects of recycled food packaging as recycling is currently considered an important means of packaging waste management. Assessing the safety of recycled packaging is very important because recycling can increase the levels of potentially hazardous chemicals in packaging and in the food after they are migrated. Various food packaging materials such as plastic, paper and cardboard, aluminum, steel, and multi-material multi-layers packaging are commonly used, but only the recycling safety of plastic food packaging materials, which is the most used and has a significant increase in post-use problem, is discussed in this review.

• Geophysics and Geophysical Exploration
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• v.12 no.1
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• pp.105-113
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• 2009

The interpretation of observed waveform characteristics identified in refraction and wide-angle reflection data increases confidence in the crustal structure model obtained. When calculating traveltimes and raypaths, wavefront methods on a regular grid based on graph theory are robust even with complicated structures, but basically compute only first arrivals. In this paper, we develop new algorithms to compute traveltimes and raypaths not only for first arrivals, but also for fast and later reflection arrivals, later refraction arrivals, and converted waves between P and S, using the modified wavefront method based on slowness network nodes mapped on a multi-layer model. Using the new algorithm, we can interpret reflected arrivals, Pg-later arrivals, strong arrivals appearing behind Pn, triplicated Moho reflected arrivals (PmP) to obtain the shape of the Moho, and phases involving conversion between P and S. Using two models of an ocean-continent transition zone and an oceanic ridge or seamount, we show the usefulness of this algorithm, which is confirmed by synthetic seismograms using the 2D Finite Difference Method (2D-FDM). Characteristics of arrivals and raypaths of the two models differ from each other in that using only first-arrival traveltime data for crustal structure analysis involves risk of erroneous interpretation in the ocean-continent transition zone, or the region around a ridge or seamount.