• 한국전자파학회:학술대회논문집
• /
• 한국전자파학회 2000년도 종합학술발표회 논문집 Vol.10 No.1
• /
• pp.16-19
• /
• 2000

We propose a deterministic vector channel simulation model satisfying not only rigorous temporal correlation but also arbitrary spatial correlation using the method of Doppler phase difference sampling. The model is more efficient than the conventional PN filtered Gaussian model with coloring process in evaluating the laboratory performance of mobile communication systems employing adaptive way antennas or space diversity.

• 지능정보연구
• /
• 제16권1호
• /
• pp.93-116
• /
• 2010

불법현금융통 적발모형 개발에 앙상블 접근방법을 사용하였다. 불법현금융통은 국내 신용카드사의 손익에 영향을 미치며 최근 국제화되고 있음에도 불구하고 학문적인 접근이 이루어지지 않았다. 부정행위 적발모형(Fraud Detection Model, FDM)은 데이터 불균형 문제로 인하여 좋은 성능을 얻기 어려운데, 다수의 모형을 결합하는 앙상블이 대안으로 제시되어 왔다. 앙상블에 포함된 모형들의 다양성이 보장된다면 단일모형에 비해 더 좋은 성능을 보인다는 점은 이미 인정되고 있으며, 최근 연구 결과는 학습된 모든 기본모형들을 사용하는 것보다 적절한 기본모형들만 선택하여 앙상블에 포함시키는 것이 바람직하다는 것이다. 본 논문에서는 효과적인 불법현금융통 적발을 위하여 축소된 앙상블 기법을 사용하는데, 정확성과 다양성 척도를 사용하여 앙상블에 참여할 기본모형을 선택하는 것이다. 다양성은 앙상블을 구성하는 기본모형들 사이의 불일치 (Disagreement or Ambiguity)를 의미하는데, FDM에 내재된 데이터 불균형문제를 고려하여 두 가지 측면에 중점을 두었다. 첫째, 학습 자료의 추출 과정에서 다양성을 확보하기 위한 소수 범주의 과잉추출 방법과 적절한 훈련 방법에 대해 설명하였다. 둘째, 소수범주에 초점을 맞추어 기존의 다양성 척도를 효과적인 척도로 변형시키고, 전진추가법과 후진소거법의 동적 다양성 계산법을 도입하여 앙상블에 참여할 기본모형을 평가하였다. 실험에 사용된 학습 알고리즘은 신경망, 의사결정수와 로짓 회귀분석이었으며, 동질적 앙상블과 이질적 앙상블을 구성하여 성능평가를 하였다. 실험결과 불법현금융통 적발모형에 있어 축소된 앙상블은 모든 기본모형이 포함된 앙상블과 성능 차이가 없었다. 축소된 앙상블은 앙상블 구성의 복잡성을 감소시키고 구현을 용이하게 한다는 점에서 FDM에서도 유력한 모형 수립 접근방법이 될 수 있음을 보였다.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2010년도 춘계학술대회 논문집
• /
• pp.1044-1053
• /
• 2010

Transmitting correct train control information is important in a train control system which demands safety. The train control information includes the maximum speed of trains, position of preceding trains, incline of tracks and curve sections etc. A radio frequency-communication based train control system is influenced by the noise and interference because the train control information is transmitted by wireless between a on-board system and wayside system. The radio frequency-communication based train control system is a mobile communication system due to moving trains. The inter symbol interference(ISI) occurs by the multipath fading in the mobile ommunication system. As signal-to-noise ratio(SNR) is decreased by the ISI, the train control information is not received correctly. In case of tunnel section, numerous reflected waves exist. Therefore, the power density of receiver is decreased by difference among the received times, magnitudes, phases through the multipath. So, the train suddenly is stopped by the fail-safe operation in the train control system on account of decreasing the power density of receiver. In this paper, a line of sight model-(Additive White Gaussian noise(AWGN) channel), rayleigh and rician fading model are presented. Probability density functions which are related to the SNR are derived from the models. The fading phenomenon severely occurs as a result of analyzing the probability density functions. So, the space diversity method is used in order to reduce the fading effect and it is demonstrated by using Matlab program.

• 한국도로학회논문집
• /
• 제13권4호
• /
• pp.211-220
• /
• 2011

최근 대중교통지향형개발(TOD)이 활발해지며, 역세권의 환경 변화를 통하여 국내의 대중교통 이용 증진을 시키기 위해서는 TOD 통합계획요소를 종합적으로 고려한 역세권 유형과 이용수요에 관한 실증분석이 전제되어야 향후 계획수립시 활용이 가능 할 것이다. 본 연구는 서울시 역세권을 대상으로 다양한 TOD 영향요인을 파악하고, 대중교통 이용수요와 연관성을 규명하기 위한 실증분석을 진행하였다. TOD의 대표적 요소인 Density, Diversity, Accessibility에 대한 자료를 수집하고, 요인분석과 회귀모형을 구축하였다. 분석결과 (1) 요인분석을 토대로 7개 영향요인이 도출되었으며, Factor 1(Diversity/토지이용복합도 (LUM)), Factor 2(Density/개발밀도수준), Factor 3(Accessibility/대중교통시설공급수준), Factor 4(Design/가로설계수준), Factor 5(Green/연계교통시설(보행자, 자전거), Factor 6(Design/지하철시설규모), Factor 7(Accessibility/대중교통운영수준)로 유형화되었다. (2) 요인-회귀분석 결과를 토대로 역세권 승하차 인원에 긍정적(+) 영향을 미치는 주요 요인은 Factor 1(Diversity : 토지이용복합도(LUM) 요인), Factor 3(Accessibility : 대중교통시설공급수준), Factor 2(Density : 개발밀도수준), Factor 5(Design/연계교통시설(보행자, 자전거), Factor 6(지하철시설규모)로 나타났다. 다음으로 역세권의 승하차 인원에 부정적(-) 영향은 Factor 7(Accessibility/대중교통운영수준)로 나타났으며, 가장 높은 영향력을 가지는 것으로 나타났다. 이는 지하철과 버스의 배차간격이 증가할 경우 이용수요가 감소하기 때문이다.

• 복식문화연구
• /
• 제8권6호
• /
• pp.791-805
• /
• 2000

The purpose of this study is to analyze the jeans advertising campaigns of the 1990's in South Korean magazine advertisements and their relation to the beauty trends of the 1990's in South Korea. There are three significant and varying periods in the 1990's. Each period will be dissected into four categories. The four categories are 1. Catchphrases 2. Pose selection of the models 3. Selection of models 4. Overall images and themes of the ads. The results are as follows : 1. 1990∼1993 ; Youth & Freedom From 1990 to 1993, jean ads emphasized the catchphrsase and the dynamic pose more and used the Korean model. The ads displayed youthful energy and the freedom of the younger generation. 2. 1994∼1997 ; Sex Appeal From 1994 to 1997, the second transition in jeans advertisements focus shifted from the youthful images of the early 90's to more sexually oriented ads. In terms of model selections and pose, Caucasian models instead of Korean models, and static pose were used more. The ads emphasized the image more than the catchphrase. 3. 1998∼1999 ; Diversity of Individuality & Naturalism During 1998 to the present day, the jeans ads no longer focused on groups but the diversity of individuality. The other focus of ads was the naturalism and the harmony with the nature. Both the static and dynamic pose, Korean model, and the image ads were used.

• Journal of Ecology and Environment
• /
• 제35권3호
• /
• pp.157-166
• /
• 2012

Many models intending to explain the latitudinal gradient of increasing species diversity from the poles to the equator are presented, which are a formalisation of the species-energy hypothesis. The model predictions are consistent with patterns of increasing species number with increasing mean air or water temperatures for plants and animals. An increase in species richness is also correlated with net primary production or the Normalised Difference Vegetation Index. This implies that increased availability of resources favours increased diversity capacity. The explanatory variables included in the biodiversity prediction models represent measures of water, energy, water-energy, habitat, history/evolution and biological responses. Water variables tend to be the best predictors when the geographic scope of the data is restricted to tropical and subtropical areas, whereas water-energy variables dominate when colder areas are included. In major models, about 20-35% of species in the various global regions (European, Africa, etc.) will disappear from each grid cell by 2050 and >50% could be vulnerable or threatened by 2080. This study provides good explanations for predictive models and future changes in biodiversity depending on various scenarios.

• 기술혁신학회지
• /
• 제1권3호
• /
• pp.326-337
• /
• 1998

This study aims to propose the model of functional specialization for university and the selection of research university in Korea. This study propose that we diversify universities into three categories ; research university, educational university, and technical university. Considering the current research capability and future research prospect of Korean universities, this study found that 8 universities could be classified as research university. However, in light of a balanced regional growth of research system two more universities could be designated as research university.

• 한국IT서비스학회:학술대회논문집
• /
• 한국IT서비스학회 2008년도 추계학술대회
• /
• pp.153-156
• /
• 2008

In recent years, IPTV attracts great attention along with the digital convergence of communication and media technologies. IPTV combines the advantages of TV and Internet and changes our lifestyle dramatically. In addition, the IPTV service is capable of becoming a new business model which has huge growth potentials in technology-converging marketplaces. This study examines critical factors on the consumer's adoption of the IPTV service. Based on the Innovation Diffusion Theory (IDT), IPTV specific attributes and personal characteristics, we derive eight key factors in the research model. compatibility, ease of use, image, diversity of contents, interactivity, monetary value, social influence, and user satisfaction. Using the partial least square (PLS) method on the data collected through a web-based survey, we test our research model with several hypotheses. From this study, we find that diversity of contents, compatibility and interactivity have a significant indirect effect on the use of IPTV service via user satisfaction, and user satisfaction and social influence also have a significant direct impact on the IPTV use. These findings not only provide practical insights on the consumer acceptance of new technology-converging services, but also help managers to plan their marketing strategies better.

• Horticulture, Environment, and Biotechnology : HEB
• /
• 제59권6호
• /
• pp.875-888
• /
• 2018

Tulip (Tulipa L.) is one of the most important ornamental geophytes in the world. Analysis of molecular variability of tulips is of great importance in conservation and parental lines selection in breeding programs. Of the 70 genic microsatellites, 15 highly polymorphic and reproducible markers were used to assess the genetic diversity, structure, and relationships among 280 individuals of 36 wild and cultivated tulip accessions from two countries: Iran and the Netherlands. The mean values of gene diversity and polymorphism information content were 0.69 and 0.66, respectively, which indicated the high discriminatory power of markers. The calculated genetic diversity parameters were found to be the highest in wild T. systola Stapf (Derak region). Bayesian model-based STRU CTU RE analysis detected five gene pools for 36 germplasms which corresponded with morphological observations and traditional classifications. Based on analysis of molecular variance, to conserve wild genetic resources in some geographical locations, sampling should be performed from distant locations to achieve high diversity. The unweighted pair group method with arithmetic mean dendrogram and principal component analysis plot indicated that among wild tulips, T. systola and T. micheliana Hoog exhibited the closest relationships with cultivated tulips. Thus, it can be assumed that wild tulips from Iran and perhaps other Middle East countries played a role in the origin of T. gesneriana, which is likely a tulip species hybrid of unclear origin. In conclusion, due to the high genetic variability of wild tulips, they can be used in tulip breeding programs as a source of useful alleles related to resistance against stresses.

• 한국간호교육학회지
• /
• 제20권3호
• /
• pp.424-434
• /
• 2014

Purpose: The aim of this study was to propose a teaching model to improve the cultural competence care of undergraduate Korean nursing students. Methods: A literature review was performed from 2000 through 2014 using internet to identify studies that presented nursing curricula and teaching-learning strategies in Korea. We analyzed retrieved Korean seven articles using Campinha-Bacote's ASKED model in combination with reflective experiences of authors observing classrooms in the U.S. Results: Six syllabuses presented information about cultural diversity nursing concepts in Korea. A traditional lecture focused on presenting contents about cultural knowledge by an instructor in the classroom was identified as a commonly used teaching strategy. We found that cultural competency related to cultural desire, awareness, and encounter was lacking. Thus, we developed teaching model based on the Korean nursing education contexts and combined with Campinha-Bacote model to improve cultural competency in nursing. Conclusions: The proposed teaching model shows promise as a strategy for improving the knowledge, attitudes, and skills related to cultural competent for undergraduate nursing students in Korea. However, evidences that this model improves nursing students' clinical practices reflecting cultural competent care are still lacking. Future research focusing on determining teaching methods and contents in clinical practices will be most effective.