• Journal of electromagnetic engineering and science
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• 제7권4호
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• pp.183-189
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• 2007

When the M-ary signal experiences the Rayleigh fading, the diversity schemes can reduce the effect of fading since the probability that all the signals components will fade simultaneously is reduced considerably. The symbol error probabilities for various M-ary signals, such as MDPSK(M-ary DPSK) and MPSK(M-ary PSK), are mathematically derived for the Selection Combining 2(SC-2) and Selection Combining 3(SC-3) demodulation system which requires a less complex receiver than maximum ratio combining(MRC). The propagation model used in this paper is the frequency-nonselective slow Rayleigh fading channel corrupted by the additive white gaussian noise(AWGN). The numerical results presented in this paper are expected to provide information for the design of radio system using M-ary modulation method for above mentioned channel environment.

• Journal of electromagnetic engineering and science
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• 제7권4호
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• pp.201-206
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• 2007

When the M-ary signal experiences the Rayleigh fading, the diversity schemes can reduce the effects of fading since the probability that all the signals components will fade simultaneously are reduced considerably. The symbol error probabilities for various M-ary signals, such as MDPSK, MPSK and MQAM, are mathematically derived for the SC-2(Selection Combining 2) demodulation system, whereby the two signals with the two largest amplitudes are coherently combined among the L branches. On the other hand, maximum ratio combining(MRC) requires the individual signals from each path to be time-aligned, cophased, optimally weighted by their own fading amplitude, and then summed. The propagation model used in this paper is the frequency-nonselective slow Rayleigh fading channel corrupted by the Additive White Gaussian Noise(AWGN). The numerical results presented in this paper are expected to provide information for the design of radio system using M-ary modulation method for above mentioned channel environment.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2001년도 추계학술대회 논문집
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• pp.91-95
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• 2001

In this study, we estimated the behavior of the diversity of physiological responses under varied physical environmental factors by measuring variations of heart rate variability (HRV), an index of activity of cardiac autonomic control. Seven healthy young male adults consented and participated in the study. The environmental conditions consisted of thermal, lighting, and acoustic conditions. Two components of HRV were measured. one was the low frequency (LF) component of HRV, which provided a quantitative index of the sympathetic and parasympathetic (vagal) activities controlling the heart rate (HR). The other component measured was the high frequency (HF) component, which provided an index of the vagal tone. The percent contribution of physical environmental factors to the variations in HRV indices were calculated by ANOVA. The contribution of physical environmental factors to the variations in HR was higher than the contribution of HF and LF. However, the contribution of these factors was lower than the contribution related with individual difference in all indices. This result showed that the individual diversity of physiological responses is not a negligible quantity.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 추계 학술논문 발표대회
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• pp.81-82
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• 2014

Modular housing has many advantages such as economy, flexibility and reusability. The domestic modular housing of a continuous stacking method has been built in military facilities, and dormitories. However, there is a limit to present diversity of low-rise multi-family housing. A cross stacking method is a way to pursue diversity of that but there is a difficulty to apply it owe to lack of cases and related technologies. Therefore, the purpose of this study is to suggest application techniques in design phase of applying the crossing stacking method in advance.

• 한국정보과학회논문지:소프트웨어및응용
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• 제32권1호
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• pp.62-73
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• 2005

진화 하드웨어(evolvable hardware)는 재구성 가능한 디지털 회로에 진화연산이 적용되어 실시간으로 환경에 적응함으로써 필요한 기능을 자동적으로 구현하는 기술이다. 이는 하드웨어 회로의 자동설계 가능성을 열어 주었지만, 아직 복잡한 회로를 얻기에는 한계가 있다. 본 논문에서는 진화 하드웨어의 적합도 공간을 분석하여, 다양한 개체가 동시에 진화되는 종분화 기법을 제안하고 그 효율성을 실험적으로 보인다. 또한 종분화 기법으로 얻은 다양한 회로를 분석하여 유용한 부가 기능이 창출될 수 있음을 보인다.

• International Journal of Advanced Culture Technology
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• 제10권4호
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• pp.529-535
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• 2022

The purpose of this study is to identify the factors that influence the revisit of jewelry stores. The purpose od this study is to find specific factors that affect product and store satisfaction. The theoretical studies on product quality, perceived quality guarantee, product design, product price, sales promotion, product diversity, store area, store re-visit intent were reviewed. Based on this background, research hypotheses were established. A total of 80 questionnaires were distributed to verify the hypothesis of the study, and 64 were finally used for the analysis. SPSS 24.0 was used for hypothesis verification. The results of this study showed that product quality, perceived product guarantee, product design, and product price had positive influence on product satisfaction. On the other hand, sales promotion, product diversity and store interior were found to have positive influence on store satisfaction. Furthermore, product and store satisfaction were found to have a positive and significant effect on revisit Jewelry Stores.

• 한국환경생태학회지
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• 제29권1호
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• pp.62-68
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• 2015

In order to get basic data for flood plain restoration, we surveyed the woody vegetation in Korean natural rivers and analyzed the species' characteristics with regards to patterns of richness and diversity. These characteristics were higher in hard wood forests than those in soft wood forests, such as Salix spp. community. Futhermore, they were the highest in the Prunus sargentii-Pinus densiflora community(H' 1.095), and the lowest in the Carpinus laxiflora community(H' 0.118) among the hard wood forests. Species' richness diversity were the highest in the Salix gracilistyla community, but the lowest in the S. koriyangi community or S. koreensis community among the soft wood forests. With regards to the dominant index, just one community is over 0.9, 13 communities are between 0.3-0.7 and 15 communities are less than 0.3. The Salix koreensis community was the highest at 0.931, and Prunus sargentii-Pinus densiflora community was the lowest at 0.13. Species' richness and diversity was significantly correlated with tree layer coverages and degree of slope. These results mean that in order to increase plant species diversity in flood plains planted hard woody trees, such as oaks and fir, are needed to suit environmental conditions with steeper slope and lower canopy coverage.

• 한국정보통신학회논문지
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• 제8권2호
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• pp.265-275
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• 2004

본 논문에서는 무선 광대역 통신망을 위한 OFDM-CDMA 광대역시스템을 설계하였다. 다중채널에서 프리앰블 설계기법을 활용함으로서, OFDM 기반의 다중안테나 전송시스템에서 시간영역의 윈도우기법의 활용에 의한 채널추정이 가능하다. 시간영역에서 직교하는 다중 안테나를 위한 각각의 프리앰블을 설계함으로서 ETSI HIPERLAN/2과 IEEE-802.11a표준에 적용가능한 채널 추정기법을 제안한다. 또한, OFDM-CDMA 기반의 광대역망에서 성능개선을 위한 다이버시티 효과를 분석하였으며, 두개의 레일레이 페이딩 채널에서 얻을 수 있는 최대의 다이버시티 이득을 계산하였다. 본 논문의 시뮬레이션 결과로 완전한 속도와 완전한 다이버시티를 가진 시공간-주파수 다이버시티기법을 적용한 OFDM-CDMA시스템에서 D=4, D=8 다이버시티의 최대 사용자수 및 절반의 사용자인 경우의 대한 다중 사용자 용량에 대한 성능을 분석하였다.

• 한국정보시스템학회지:정보시스템연구
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• 제30권4호
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• pp.303-327
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• 2021

Purpose The online comments on news content have become social information and are understood based on deliberative democracy. Although the related research has focused on the relationship between online comments and their deliberative quality, the social information provided by online comments consists of not only direct information such as comments themselves but also indirect information such as 'likes' and 'dislikes'. Therefore, the research on online comments and deliberative quality should study this direct and indirect information together, and the direction and the degree of the indirect information should be also considered with them. Design/methodology/approach This study distinguishes comments by the attached 'likes' and 'dislikes', identifies highly supported and highly unsupported comments by the intensity of 'likes' and 'dislikes', and investigates the relationship between their existence and the deliberative quality measured as the topic diversity. Then, we applied topic modeling to the 2,390 news articles and their 74,385 comments collected from five news sites. Findings The topic diversities of the supported and unsupported comments are related to the topic diversity of all comments but the degree of the relationship is higher in the case of supported comments. Furthermore, the existence of highly supported and unsupported comments is led to less diversity of all comments compared to the case where those comments are absent. Particularly, when only highly supported comments are present, topic diversity was lower than in the opposite case.

• 대한가정학회지
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• 제47권7호
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• pp.83-95
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• 2009

This study investigated the differences in the effects of the perception of the internet fashion shopping mall characteristics on satisfaction and loyalty of internet fashion shopping mall between Korean and American college students. Questionnaires were administered to 251 Korean and 221 American college students. The results were as follows. First, service and product diversity had significant effects on satisfaction of internet fashion shopping mall in both group, while convenience had a significant impact on satisfaction of internet fashion shopping mall in American group. Second, service, product diversity, and promotion had significant influences on repurchase intention of internet fashion shopping mall in Korean consumer group, while service and reliability, product diversity, and convenience had significant effects on repurchase intention of internet fashion shopping mall in American consumer group. Third, service had a significant effect on recommendation intention in Korean group, while service and reliability and product diversity had significant influences on recommendation intention in American group.