• 한국전자파학회논문지
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• 제25권7호
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• pp.747-756
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• 2014

본 논문에서는 다이버시티 효과를 사용하여 다중 안테나를 고려한 경로 손실 모델을 제안한다. 현재까지 진행되어진 연구 중 대다수는 경로 손실 모델은 송신단과 수신단 사이의 지리적 환경을 고려한 모델은 많았지만, 다중 안테나를 고려한 모델은 상대적으로 연구가 적게 진행되었다. 현재 무선 통신 시스템에서도 다중 안테나를 사용한다. 더욱이 지속적인 통신 용량 개선을 위한 방법으로 다이버시티 기법을 사용하는 사례도 쉽게 찾아볼 수 있다. 하지만 이러한 통신 시스템에서 수신 신호의 세기를 예측할 수 있는 경로 손실 모델은 현재 확립되지 않았다. 따라서 이와 같은 환경에서 수신 신호 전력의 변화를 예측하기 위해 다이버시티 이득으로 변화된 SNR(Signal to Noise Ratio)을 구한다. 제안하는 모델에서 수신단의 안테나의 개수가 7개 이상일 때부터 다이버시티 효과가 일정 값으로 수렴하기 때문에 수신단의 안테나의 개수는 10개인 경우까지 고려하였다. 제안한 모델과 연산을 통한 계산값의 RMSE(Root Mean Square Error)는 1이내 임을 확인하였다. 즉, 기존의 BER(Bit Error Rate) 곡선으로부터 다이버시티 이득을 계산하였고, 다중 안테나를 사용한 통신 시스템 모델에서 예측할 수 없었던 수신 신호의 세기를 본 논문에서 제안한 경로 손실 모델을 통하여 예측이 가능하다.

• 산업경영시스템학회지
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• 제40권1호
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• pp.144-149
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• 2017

This study empirically analyzes the effect of IT SME ventures' external information network diversity on their production period reduction and productivity improvement generated from technology development. This research constructs a mediating model based on the open innovation perspective and tests it with the 138 samples of South Korean IT SME ventures based on the ordinary least squares regression. This research is expected to make a good contribution by shedding a new light on the following three points about the critical role of IT SME ventures' external information network diversity in increasing their production period reduction and productivity improvement generated from technology development which has scarcely been illuminated in the extant studies in the field of the management of technology for SMEs. First, IT SME ventures' external information network diversity positively influences their production period reduction. Second, the external information network diversity positively influences IT SMEs' ventures' productivity improvement. Third, IT SME ventures' production period reduction partially mediates the influence of IT SME ventures' external network diversity on their productivity improvement. These three fresh points are expected to provide useful theoretical and practical implications. Related to the theoretical implication, this research provides a fresh implication that IT SME ventures' external information network diversity positively influences not only their production period reduction but also productivity improvement generated from technology development. Concerning the practical implication, this study suggests that the CEOs in IT SME ventures make strategic efforts to use more diverse external information sources in order to increase their production period reduction and productivity improvement generated from technology development.

• 대한전자공학회논문지TC
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• 제45권11호
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• pp.23-31
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• 2008

이 논문에서는 OFDM 및 SC-FDE 시스템에서 다이버시티 기술의 적용이 채널부호화율에 미치는 상관관계에 대해서 살펴본다. OFDM 시스템에서는 채널의 다중경로 프로파일에 따라서 적절한 채널부호화율의 결정이 필요하며 순환지연 다이버시티 기술을 적용하는 경우가 시공간 부호화 기술을 적용하는 경우보다 더 낮은 채널부호화율을 필요로 한다. 이에 반해서 OFDM에 DFT 확산을 적용한 SC-FDE 시스템에서는 낮은 채널부호화율을 적용할 필요성이 없으며 다이버시티 기술의 적용과 상관없이 상대적으로 높은 채널부호화율이 사용될 수 있다.

• 환경생물
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• 제18권1호
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• pp.53-61
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• 2000

서울시 소재 지하수 중 중금속으로 오염되어 음용수 이외의 생활 용수로 사용하고 있는 1개 정점과 음용수로 사용하고 있는 1개 정점, 대조군으로 강화도 천연 동굴의 1개 정점을 대상으로 실험을 실시하였다. 지하수 세균군집의 유전적 다양성의 변화를 보기 위해 지하수 세균 군집에서 16SrDNA를 증폭하는 primer로 PCR(polymerase chain reaction)을 실시한 후 ARDRA(amplified ribosomal DNA restriction analysis) 지문 분석으로 비교하였다. 16S rDNA를 증폭하여 제한효소 지문분석을 한 결과 in situ와 음용수에서 유전적 다양성이 상대적으로 크게 나타났다. 지하수 세균 군집의 ARDRA지문 분석은 상이한 환경과 서식지를 반영한 유전적 차이를 빠르게 비교 분석할 수 있었으며 지하수의 오염도에 따른 미생물의 다양성(천연 동굴>음용수>오염수)을 확인할 수 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제21권2호
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• pp.177-180
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• 2008

In this study, cattle microsatellite markers recommended for diversity studies of cattle by the EU AIRE 2066 Concerted Action Group were used to study the genetic diversity of 105 Thai swamp buffalo which were randomly selected from eight different research stations of the Department of Livestock Development, Thailand. Of 34 primer pairs, 16 were successfully amplified while the rest showed non-specific amplification. The lowest number of alleles was two while the highest was nine, with an average of 4.7 alleles per locus. The average unbiased heterozygosity for all eight populations was 0.5233, with a low of 0.4772 (Samui) and a high of 0.5616 (Burirum). The genetic distance ranged from 0.0574 to 0.2575. Populations from Lopburi and Burirum showed the closest relationship, whereas Srisagat and Samui were the most divergent. The results generated with the primers recommended by the EU AIRE 2066 Concerted Action Group are at a slight variance from our previous study, possibly as a result of the number of specific amplification products obtained, suggesting that cattle markers may not be optimal for studies of the genetic diversity of the Thai swamp buffalo.

• Asian-Australasian Journal of Animal Sciences
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• 제23권12호
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• pp.1552-1556
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• 2010

The aim of this study was to evaluate, through the use of microsatellite markers, the current genetic diversity and the relationships of 375 individuals from 8 local sheep breeds reared in typical breeding farms in the northwest of China, and moreover, to offer a contribution towards genetic conservation decisions for the studied breeds. The expected heterozygosities and allelic richness for the 8 breeds varied from 0.474 to 0.623 and from 3.8 to 5.4, respectively. All the populations showed a significant deficit in heterozygosity and a relatively low level of genetic diversity. Furthermore, the high positive FIS value (ranging from 0.255 to 0.556) indicated inbreeding to be one of the main causes for high genetic homogeneity and lack of heterozygosity in all breeds. The clustering analysis performed with the DISPAN package showed that Aletai, Kazak, Bashibai and Bayinbuluke were grouped together, and Hetian, Qira black and Duolang were grouped together, which indicated that the relationship among breeds displayed some degree of consistency with their geographical distribution, production and origin. These findings indicate that improved conservation measures must be undertaken to avoid further losses of genetic diversity and minimize inbreeding represented by these breeds.

• 한국약용작물학회지
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• 제21권3호
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• pp.220-228
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• 2013

This study was conducted to assess the genetic diversity and population structure of 70 amaranth accessions collected from South and Southeast Asia using 14 simple sequence repeat (SSR) markers. In total, 67 alleles were detected, with an average of 4.79 per locus. Rare alleles comprised a large portion (46.3%) of the detected alleles, and 29 unique alleles associated with rice accessions were also discovered. The mean major allele frequency (MAF), genetic diversity (GD) and polymorphic information content (PIC) of the 14 SSR loci were 0.77, 0.36, and 0.34, respectively. A model-based structural analysis revealed the presence of three subpopulations. The genetic relationships revealed by the neighbor-joining tree method were fairly consistent with the structure-based membership assignments for most of the accessions. All 70 accessions showed a clear relationship to each cluster without any admixtures. We observed a relatively low extent of genetic exchange within or among amaranth species from South and Southeast Asia. The genetic diversity results could be used to identify amaranth germplasms and so facilitate their use for crop improvement.

• 한국환경복원기술학회지
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• 제21권1호
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• pp.73-82
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• 2018

Urban parks are important bird habitat in cities. Various studies have evaluated the habitat function of urban parks focused on field surveys. In this study, we performed applicability of NDVI obtained from Landsat 8 OLI image as a factor for spatial planning considered bird diversity. This study was classified with green boundary into three groups using NDVI's value. Environmental variables were calculated by the green area ratio of the surrounding area from 100m to 500m at each groups. The 20 environmental variables such as park area, park shape index, canopy of tree, etc. were derived, the regression analysis was performed as a dependent variable for the bird diversity of urban parks. As a result, the park area and the green area ratio of Group 3, classified high NDVI, within the 100m buffer were adopted as the variables in the regression model. In other words, it was confirmed that as the park becomes larger, the distribution of key green areas within a radius of 100m of the parks becomes higher, the diversity of bird species has increased. It was appropriate to use satellite image, NDVI to analyze species diversity in urban area.

• 한국의상디자인학회지
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• 제14권3호
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• pp.11-22
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• 2012

As the consuming pattern is changing with the expansion of Internet use and the development of communication technology, Internet shopping market is getting bigger and bigger. By product group, clothing and fashion related products occupy the biggest share. Accordingly, in this study it was tried to identify the effects of Internet utilization capability that enables consumers to search for the information that they need in this information flood, variety pursuit trend and product review accommodation status on shopping value, and to analyze the effects of the shopping value on the purchase behavior in online shopping malls. When factor analysis is nude on Internet use level, it was found that Factor 1 was 'Flow Experience,' Factor 2 'Internet Use Capability,' and Factor 3 'Internet Challenge Desire.' When factor analysis is made on Diversity Pursuit Propensity, it was found that Factor 1 was 'Site Diversity Pursuit Propensity,' Factor 2 'Brand Diversity Pursuit Propensity,' and Factor 3 'Brand Value Pursuit Propensity.' When factor analysis is nude on Product Review Accommodation Propensity, it was found that Factor 1 was 'Product Information Provision Propensity,' and Factor 2 'Product Information Receiving Propensity.' Except Internet Use Capability and Product Information Provision Propensity, all other factors showed high correlation. The factor influencing the entertainment value most was Internet challenge desire, while that influencing the practical value most was flow experience. When the effects of the entertainment value and the practical value on product purchase were analyzed, it was found that both of entertainment value and the practical value influenced product purchase and the practical value influenced the product purchase more than the entertainment value.

• 디지털융복합연구
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• 제16권6호
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• pp.117-126
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• 2018

본 연구는 VR기기를 중심으로 VR기기 수용을 결정하는 다양한 요인들을 제출하고 이러한 요인들과 소비자들의 수용의도와의 관계를 분석하고자 하였다. 본 연구의 목적을 위해 VR기기를 사용해 본 중국 소비자 238명의 설문조사 데이터를 수집하여 AMOS 23.O를 이용하여 분석하였다. 연구결과, 콘텐츠 다양성과 자기효능감이 지각된 용이성, 지각된 유희성과 지각된 유용성에 유의한 영향을 미치는 것으로 나타났다. 지각된 용이성은 지각된 유희성을 경유하여 지각된 유용성에 간접적인 영향을 미치는 것으로 나타났다. 마케팅커뮤니케이션은 수용의도에 유의한 영향을 미쳤지만 지각된 가격은 수용의도에 유의하게 나타나지 않았다. 지각된 유용성, 지각된 용이성, 지각된 유희성은 모두 VR기기의 수용의도에 영향을 미치는 것으로 확인되었다. 본 연구의 결과는 VR기기에 주목하고 있는 기업이 타겟으로 하는 소비자들을 위해 고려해야 하는 요소들을 이해할 수 있는 유용한 마케팅 전략을 제공할 수 있을 것으로 기대한다.