• Economic and Environmental Geology
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• v.53 no.4
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• pp.479-489
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• 2020

A fault is a geological structure that can be a migration path or a cap rock of hydrocarbon such as oil and gas, formed from source rock. The fault is one of the main targets of seismic exploration to find reservoirs in which hydrocarbon have accumulated. However, conventional fault detection methods using lateral discontinuity in seismic data such as semblance, coherence, variance, gradient magnitude and fault likelihood, have problem that professional interpreters have to invest lots of time and computational costs. Therefore, many researchers are conducting various studies to save computational costs and time for fault interpretation, and machine learning technologies attracted attention recently. Among various machine learning technologies, many researchers are conducting fault interpretation studies using the support vector machine, multi-layer perceptron, deep neural networks and convolutional neural networks algorithms. Especially, researchers use not only their own convolution networks but also proven networks in image processing to predict fault locations and fault information such as strike and dip. In this paper, by investigating and analyzing these studies, we found that the convolutional neural networks based on the U-Net from image processing is the most effective one for fault detection and interpretation. Further studies can expect better results from fault detection and interpretation using the convolutional neural networks along with transfer learning and data augmentation.

• Journal of Internet Computing and Services
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• v.10 no.5
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• pp.41-47
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• 2009

Routing through a backbone, which is responsible for performing and managing multipoint communication, reduces the communication overhead and overall energy consumption in wireless sensor networks. However, the backbone nodes will need extra functionality and therefore consume more energy compared to the other nodes. The power consumption imbalance among sensor nodes may cause a network partition and failures where the transmission from some sensors to the sink node could be blocked. Hence optimal construction of the backbone is one of the pivotal problems in sensor network applications and can drastically affect the network's communication energy dissipation. In this paper a distributed algorithm is proposed to generate backbone trees through robust multi-hop clusters in wireless sensor networks. The main objective is to form a properly designed backbone through multi-hop clusters by considering energy level and degree of each node. Our improved cluster head selection method ensures that energy is consumed evenly among the nodes in the network, thereby increasing the network lifetime. Comprehensive computer simulations have indicated that the newly proposed scheme gives approximately 10.36% and 24.05% improvements in the performances related to the residual energy level and the degree of the cluster heads respectively and also prolongs the network lifetime.

• Applied Chemistry for Engineering
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• v.19 no.5
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• pp.554-558
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• 2008

$(1-x)SiO_2-(x)TiO_2$ composite fibers with various compositions of $TiO_2$ were prepared by electrospinning their sol-gel precursors of titanium (IV) iso-propoxide (TiP), and tetraethyl orthosilicate (TEOS). The surface morphology and structure of sintered composite fibers were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), simultaneous thermogravimetric analysis-differential scanning calorimetry (TGA-DSC) and Fourier transform infrared spectroscopy (FT-IR). As the content of $TiO_2$ in $(1-x)SiO_2-(x)TiO_2$ system was increased the average diameter of composite fibers was proportionally increased. Also, the transformation of $TiO_2$ from anatase to rutile form was inhibited by the highly dispersed $TiO_2$ around $SiO_2$ particles up to $0.6SiO_2-0.4TiO_2$ composite fibers even after calcination at $1000^{\circ}C$. The photocatalytic activity of $SiO_2-TiO_2$ composite fibers was examined for the methylene blue (MB) decomposition which was confirmed using UV-vis/DRS spectra. The experiments demonstrated that the MB in aqueous solution was successfully photodegraded using $SiO_2-TiO_2$ composite nanofibers under UV-visible light irradiation.

• Journal of Korea Spatial Information System Society
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• v.3 no.1 s.5
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• pp.49-62
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• 2001

Recently, component-based software has become main trends in designing and developing computer software products. This component-based software has advantage of the interoperability on distributed computing environment and the reusability of pre-developed components. Also, GIS is designed and implemented with this component-based methodology, called Open GIS Component. OGC(OpenGIS Consortium) have announced various implementation and design specification and topic in GIS. In GIS, Spatial analysis functions like network analysis, TIN analysis are very important function and basically, estimate system functionality and performance using this analysis methods. The simple feature geometry specification is announced by OGC to increase the full interoperability of various spatial data. This specification includes just geometry spatial data model. However, in GIS which manages spatial data, not only geometric data but also topological data and various analysis functions have been used. The performance of GIS depends on how this geometric and topological data is managed well and how various spatial analyses are executed efficiently. So it requires integrated spatial data model between geometry and topology and extended data model of topology for spatial analysis, in case network analysis and TIN analysis in open GIS component. In this paper, we design analysis component like network analysis component and TIN analysis component. To manage topological information for spatial analysis in open GIS component, we design extended data model of simple feature geometry for spatial analysis. In addition to, we design the overall system architecture of open GIS component contained this topology model for spatial analysis.

• Journal of Hospice and Palliative Care
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• v.15 no.4
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• pp.193-204
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• 2012

Purpose: This correlation study was performed to examine Korean adults' perceptions and attitudes towards death with dignity and the withdrawal of life sustaining treatment and to identify factors that predict their attitude towards death with dignity. Methods: The study was conducted using convenience sampling of 291 adults from three towns of a metropolitan city in Korea. Data were collected using structured questionnaires which surveyed people's perception about and attitudes towards withdrawal of life sustaining treatment and scaled their attitude towards death with dignity. Data were analyzed by using descriptive statistics, Pearson correlation coefficients and multiple regression. Results: The attitude towards the withdrawal of life sustaining treatment and death with dignity showed a significant positive correlation (r=0.49, P<0.001). For attitudes towards death with dignity, significant predictors were attitudes towards the withdrawal of life sustaining treatment, age, religion, a proper withdrawal process and advanced medical directives, which explained 49.3% of total variance. Conclusion: The results of this study may contribute to development of a new medical decision-making system including nurses' appropriate roles in the process of withdrawing life sustaining treatment and advanced medical directives.

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.1072-1076
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• 2010

본 지역 재정지표와 표준화사망률간의 관계에 대한 것으로, 연구대상지역은 1998년부터 2007년까지의 전국 232개 시 군 구이며 이를 5개 광역권과 4개 도시 종류에 따라 분류하였다. 지역 재정지표는 1인당 지방세부담액과 재정자립도, 재정자주도, 의존재원비율을 활용하였고, 지역 총사망률은1998년에서 2007년까지의 통계청 사망 원자료 상의 사망자수를 분자로, 주민등록인구를 분모로 직접 표준화법을 사용하여 연구대상 지역의 성 연령표준화사망률을 산출하였다. 자료의 분석은 SPSS 12.0K를 이용하여 상관분석, 일원배치분산분석(Tukey b 사후검정) 및 회귀분석을 실시하였다. 주요 결과로는 첫째, 재정지표와 표준화사망률간의 상관분석을 실시하여 연도별로 계수 값을 구한 결과 1인당 지방세부담액을 제외하고 재정자립도, 재정자주도, 의존재원비율 모두 남자, 여자, 전체 모두가 전 연도에 걸쳐 상관계수 값이 통계적으로 유의하였으며, 남자가 여자보다 높은 상관관계를 보였다. 둘째, 재정자립도, 재정자주도 각각을 표준화사망률과 단순 회귀분석을 실시한 결과, 표준화사망률 남자, 여자, 전체가 전 연도에서 통계적으로 유의하였고, 재정자립도와 재정자주도가 낮을수록 사망률이 높은 것으로 나타났다. 셋째, 광역권역, 도시 종류까지 고려한 재정지표의 다중회귀분석을 실시한 결과, 1인당 지방세부담액과 의존재원비율, 광역권역과 도시 종류에 따른 지역을 고려하고도 재정자주도의 효과는 전체사망과 남자, 여자, 전 연도에 걸쳐 모두 통계적으로 매우 유의하여 재정자주도가 높을수록 사망률이 낮은 것으로 나타났고 이런 경향은 여자보다 남자에서 더욱 강하게 나타났다. 넷째, 광역권별 분석의 경우, 충청권은 수도권에 비해서 표준화사망률에서 유의한 차이는 없었으며 호남권과 영남권은 전체 표준화사망률의 경우 전체 연도의 절반 이상에서 수도권에 비해서 통계적으로 유의하게 높았고, 남자와 여자에서는 이런 경향이 약해졌다. 강원 제주권은 전체 사망에서 수도권에 비해 전체 연도의 절반 이상이 유의하게 사망률이 낮았으며, 여자도 이와 비슷한 양상을 보여주었다. 다섯째, 도시 종류에 따른 분석에서 대도시에 비해 중소도시는 통계적으로 유의한 차이는 없었으나, 전 연도에 걸쳐 도농통합도시와 군지역은 대도시에 비해 통계적으로 사망률이 높았다. 여섯째, 전 연도에 걸쳐 의존재원비율이 높아질수록 사망률이 유의하게 높아졌다. 이는 남자, 여자 모두에서 유사하게 나타났다. 마지막으로 연도별 분석 이후 1998년에서 2007년 전체 다중 회귀분석을 실시한 결과 전체 사망과 여자의 경우 1인당 지방세부담액을 제외한 모든 변수에서 통계적으로 유의하였다. 지역의 재정력이 성 연령 표준화사망률에 영향을 미치는 것으로 파악되었는데 이를 단서로 지역의 건강 격차가 발생하는 원인과 기전을 밝히기 위해 향후 보다 면밀한 후속 연구가 이뤄져야 하겠고 지역 간 건강 격차를 완화하기 위한 여러 방법론적 고찰 안에 지역간 재정력의 격차를 완화하려는 정책적인 접근도 필요할 것으로 사료된다.

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.1205-1208
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• 2010

본 연구는 초등학교 5, 6학년 학생의 인터넷 중독과 학교생활 적응과의 관계를 파악하여 인터넷 사용에 대한 교육적 지도방안과 인터넷 중독 예방프로그램 개발의 기초 자료를 제공하고자 시도되었다. 자료는 2009년 7월 1일에서 7월 24일까지 제주특별자치도에 위치한 초등학교 6개교(동지역 4개교, 읍지역 2개교)를 무작위 추출하여 5, 6학년 학생 총 1195명을 대상으로 조사하였다. 자료 분석은 SPSSWIN(12.0 한글판) 프로그램을 이용하여 카이제곱검정, t-검정, 일원배치 분산분석, 상관분석, 다중회귀분석의 통계적 방법을 이용하였다. 본 연구의 주요 결과는 첫째, 대상자의 인터넷 중독 정도는 고위험군 55명(5.5%), 잠재적위험군 49명 (4.9%), 정상군 900명(89.6%)으로 나타났으며, 둘째, 대상자의 일반적 특성에 따른 인터넷 중독 정도를 분석한 결과 성별, 형제자매 유무, 학교성적에 따라 유의한 차이가 있었다. 셋째, 대상자의 컴퓨터 사용 특성에 따른 인터넷 중독 정도는 최초 인터넷 이용 시기, 인터넷 이용용도, 하루 인터넷 사용 시간, 부모컴퓨터 사용 여부에 따라 유의한 차이가 있었으며, 넷째, 인터넷 중독과 학교생활 적응과의 관계를 분석한 결과 학교생활 부적응인 경우는 '고위험군' 32명(58.2%), '잠재적위험군' 24명(50.0%), '정상군' 257명 (28.7%)으로 고위험군과 잠재적위험군이 정상군보다 학교생활 적응 정도가 낮은 것으로 조사되었다(p<0.01). 다섯째, 인터넷 중독에 유의한 영향을 주는 변수는 학교생활 적응 정도, 성별, 하루 인터넷 사용시간, 인터넷 이용용도, 인터넷 이용 상황, 어머니 직장 유무, 거주 지역, 부모 컴퓨터 사용여부, 최초 인터넷 이용시기이었다. 학교생활 적응 정도가 낮을 때, 남학생, 하루 인터넷 사용시간이 3시간 이상, 인터넷 이용 용도가 '게임', '스트레스가 쌓였을 때' 인터넷을 이용하는 경우, 어머니 직장이 있는 경우, 거주 지역이 동지역, 부모님이 컴퓨터를 사용할 줄 모르는 경우, 최초 인터넷 이용 시기가 취학 전인 경우가 인터넷 중독 점수가 높은 것으로 나타났다. 여섯째, 학교생활 적응에 유의한 영향을 주는 변수는 인터넷 중독 점수, 학교성적, 가정경제수준, 거주지역, 인터넷 이용용도, 학년이었다. 인터넷 중독 점수가 낮을수록, 학교성적이 높을수록, 가정경제수준이 잘 살수록, 거주지역이 동지역, 인터넷 이용용도가 '정보검색, 홈페이지관리/메신저', 5학년인 경우에 학교생활 적응을 더 잘하고 있는 것으로 나타났다. 이상의 결과를 종합해 보면, 학교생활 적응 정도가 낮을수록 인터넷 중독 점수가 높게 나타나고 있고, 인터넷 중독 경향이 높을수록 학교생활 적응 수준이 낮게 나타나고 있음을 알 수 있다. 아동들은 하루중 대부분의 시간을 학교에서 생활하고 있기 때문에 학교생활 적응은 아동들이 건전한 성인으로 성장하는데 중요한 요인이 된다. 또한, 인터넷사용률 증가와 최초 인터넷 이용 연령층이 점점 낮아지고 있음에 따라 인터넷 중독률이 자연스럽게 점점 높아질 것으로 예측되어진다. 따라서, 가정과 학교가 연계하여 아동들의 인터넷 사용에 대한 지속적인 관심과 지도가 필요하며, 인터넷 중독경향이 높은 아동들이 학교생활 적응을 잘할 수 있도록 인터넷 중독 치료 및 예방교육 프로그램 운영이 필요하다 하겠다.

• Journal of Broadcast Engineering
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• v.21 no.2
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• pp.169-179
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• 2016

Recently, MPEG-H has been standardizing for a multimedia coder in UHDTV (Ultra-High-Definition TV). Thus, the demand for not only channel-based audio contents but also object-based audio contents is more increasing, which results in developing a new technique of converting channel-based audio contents to object-based ones. In this paper, a non-uniform linear microphone array based source separation method is proposed for realizing such conversion. The proposed method first analyzes the arrival time differences of input audio sources to each of the microphones, and the spectral magnitudes of each sound source are estimated at the horizontal directions based on the analyzed time differences. In order to demonstrate the effectiveness of the proposed method, objective performance measures of the proposed method are compared with those of conventional methods such as an MVDR (Minimum Variance Distortionless Response) beamformer and an ICA (Independent Component Analysis) method. As a result, it is shown that the proposed separation method has better separation performance than the conventional separation methods.

• Journal of Science Education
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• v.37 no.2
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• pp.405-415
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• 2013

The purpose of this study was to investigate high school students in natural science track and engineering major university students' perceptions about the writing and composition education. A total of 318 high school students in natural science track from two high schools in a metropolitan area and 447 university students majoring in engineering from three universities participated in the survey and asked to response their perceived status and needs of writing education for science-engineering track. The survey instrument, developed by Lee et al.(2009), was used for this study. The data was analyzed through the SPSS 18.0 program for Windows for Multiple Response Frequency Analysis, Descriptive Statistics, Independent Samples t-test, and One-way Analysis of Variance. The results indicated that high school students relatively perceived that writing education was less necessary compared to university students. In addition, high school students found writing less difficult than university students do. In related to studying their experience with writing and composition education, almost no high school students have taken writing classes and university students have taken an average of one class. Most university students who took writing classes took basic writing classes that were not programmed for students in Science and Engineering. In the basic survey to revitalize writing and composition education for Science and Engineering students in different majors, the level of writing and composition education required by students in each major was different. Writing was considered most necessary for students majoring in Chemical Engineering, followed by students majoring in Mechanical Engineering and Electronic Engineering. The study of writing and composition education for high school and college should extend to studies on teachers or professors who teach writing, studies on contents and methods of writing education, and studies on the development of writing programs for different majors in university.

• Journal of Hospice and Palliative Care
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• v.7 no.2
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• pp.179-188
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• 2004

Purpose: The purpose of this study was to investigate the degree of fatigue and its related factors in cancer patients during chemotherapy. Methods: The subjects of this study consisted of 90 patients over 20 years old who were receiving chemotherapy at the injection room of the o.p.d. and ward admission care unit in a University hospital located in Gwang-ju city and data were collected from August 8th to October 2nd, 2002. Collected data were analysed using SPSS v 10.0. to obtain summary statistics for the descriptive analysis, t-test, ANOVA, pearson correlation, and multiple regression. Results: 1. Fatigue of the subjects was significantly correlated with physical distress score. and 6 items of subscale those were nausea, vomiting, anorexia, pain, and immobility, showed statistically significant correlation. 2. Fatigue of the subjects showed statistically significant differences according to a nap satisfaction. Fatigue of the subjects was significantly correlated with mood state, Also, all 5 items of subscale, which are those were anxiety, confusion, depression, energy, and anger showed statistically significant correlations. 3. Fatigue of the subjects showed statistically significant differences according to metastasis, chemotherapy cycle, post operation existence, post radiation therapy existence. There were significant negative correlation between fatigue and hematocrit and fatigue and weight change. There was no significant correlation between fatigue and spiritual well-being state. With the result to multiple regression, Immobility, Anorexia, Anger explained fatigue by, pain, and immobility showed statistically significant correlation.