• 대한공간정보학회지
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• 제16권4호
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• pp.59-64
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• 2008

우리나라의 야생동식물 조사가 시간적, 경제적 이유로 주로 출현지역만을 대상으로 하고 있어 종분포모형을 개발할 때 각 모형의 장점을 최대한 이용하는 것이 필요하다. 본 연구는 위치자료의 종류(출현/비출현자료)에 따라 가장 대표적인 출현/비출현모형(presence-absence model)인 GAM(Generalized Additive Model)과 출현모형(presence-only model)인 Maxent(Maximum Entropy Model)를 이용하여 비교 검토하였다. 본 연구의 대상종으로는 캘리포니아의 보호종인 피셔(Martes pennanti)를 선정하고 대상지를 지역에 따라 나누었으며, 서식지환경을 설명하는 지형, 기후, 식생변수들을 이용하여 모형을 적용하였다. 그 결과 첫째, 실제 출현/비출현자료를 사용한 GAM이 임의 비출현자료를 사용한 GAM과 출현자료만을 사용한 Maxent보다 전체적으로 나은 것을 볼 수 있었다. 둘째, 실제 출현자료만을 이용한 모형을 개발할 경우 임의 비출현자료를 이용한 GAM보다 출현자료만을 이용한 Maxent가 더 나은 것을 알 수 있었다. 마지막으로 세부지역에서 개발된 모형(Klamath/Shasta, Sourthern Sierra)은 서로 서식환경이 다를 경우 다른 지역의 서식지를 잘 예측하지 못함을 알 수 있었고, 대상지 외부지역에 대해 과추정하는 경향을 보였다. 위 결과를 바탕으로 위치자료의 종류, 공간적 분포 등을 감안하여 대상지의 환경에 알맞은 모형을 선택하는 것이 바람직할 것으로 판단된다.

• Communications for Statistical Applications and Methods
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• 제29권5호
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• pp.533-545
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• 2022

Collection of data on several variables, especially in the field of medicine, results in the problem of measurement errors. The presence of such measurement errors may influence the outcomes or estimates of the parameter in the model. In classification scenario, the presence of measurement errors will affect the intrinsic cum summary measures of Receiver Operating Characteristic (ROC) curve. In the context of ROC curve, only a few researchers have attempted to study the problem of measurement errors in estimating the area under their respective ROC curves in the framework of univariate setup. In this paper, we work on the estimation of area under the multivariate ROC curve in the presence of measurement errors. The proposed work is supported with a real dataset and simulation studies. Results show that the proposed bias-corrected estimator helps in correcting the AUC with minimum bias and minimum mean square error.

• 한국정보통신학회논문지
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• 제26권12호
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• pp.1855-1862
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• 2022

Beacon을 이용한 실내 재실 여부 결정 및 실내 측위 기술을 통해 다양한 실내 위치기반 서비스를 제공할 수 있다. 하지만, Beacon이 송출하는 BLE 신호는 다중 경로 페이딩 등의 문제로 인해 RSSI 값이 불안정하기 때문에 재실 여부 결정의 정확도를 보장하기 어렵다. 본 논문에서는 다양한 상황에서도 정확성을 보장하기 위해 강의실의 문이 열린 상태에서 데이터를 수집하였다. 수집된 데이터를 기반으로 신호의 특성을 고려한 재실 여부 결정 방법을 제안한다. 제안된 방법은 SVM 모델을 사용하며, 수신 신호 강도만을 사용한 결과에 비해 약 10% 정확도 향상을 보였다. 이 방법은 수신기 하나만으로도 재실 여부를 정확하게 판단할 수 있다는 장점이 있다. 제안된 방법을 통해 정확도 높은 염가형 재실 여부 결정 시스템을 구현할 수 있을 것으로 기대된다.

• 한국식품영양과학회지
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• 제20권1호
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• pp.40-45
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• 1991

The release of hepatic triglyceride lipase from cultured rat hepatocytes and its hormonal regulation were studied. The activity of lipase released into the medium in the presence of heparin was increasing during 24 hours on the 2nd of culture while this was 10% in the absence of heparin as compared with the lipase activity in the presense of heparin. When hepatocytes were cultured with anti-hepatic triglyceride lipase lgG the lipase activity was supp-ressed by 92% The results suggest that the enzyme relaeased into culture medium is identical to hepatic triglyceride lipase which can be released only in the presence of heparin the model of release being similar to that of lipoprotein lipase from adipocytes. The addition of monensin to the medium resulted in The inhibition of lipase secretion by 61% Insulin enhanced lipase activity only 20% whereas dexamethasone suppressed the activity by 44% These data inidica-ted that hepatic triglyceride lipase is secreted and released from hepatocytes in the presence of heparin and its secretion is regulated by hormones.

• 유통과학연구
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• 제14권10호
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• pp.165-178
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• 2016

Purpose - This study aims to empirically verify the impact of media richness, social presence, and prior life satisfaction on various continual usage or withdrawal behaviors of SNS users via both a positive path of satisfaction and a negative path of relative deprivation. By identifying these causal paths, we observe dynamic interactions of SNS user psychology in a balanced view, and provide some implications about design principles for SNS providers. Research design, data, and methodology - We developed 16 hypothesis based on media richness theory, social presence theory, social comparison theory, the literature about relative deprivation, and the literature about the various reactions of IS users. The rich SNS media, social presence recognition among peer SNS users, and prior life satisfaction could generate positive experience, attitude, and virtuous behavioral intentions among SNS users. At the same time, rich media, low social presence, and low prior life satisfaction could generate relative deprivation and could increase withdrawal behavioral intentions such as refusal to provide information, misrepresentation of information, and removal of uploaded information in SNS. Scenario surveys were conducted to collect data from potential SNS users. Data from 357 surveys were collected and analyzed through a PLS algorithm to test the hypotheses. Results - Media richness, social presence, and prior life satisfaction could significantly increase perceived enjoyment, satisfaction, and behavioral intention of continual usage and knowledge sharing. They also could significantly decrease refusal and misrepresentation intention. Relative deprivation is significantly decreased only by prior life satisfaction. Relative deprivation could not significantly decrease satisfaction, but it could significantly increase misrepresentation and removal intention, which could be regarded as information distortion intention. Conclusions - SNS providers should focus on developing rich media and social presence support because these two variables could impact the positive experiences of SNS users. Moreover, the positive experiences could heavily influence SNS user behavior. Some management is needed to prevent relative deprivation and its consequences of misrepresentation and removal intention. SNS providers should prevent SNS users from excessive image misrepresentation and removal as this information distortion could be the source of relative deprivation.

• 한국의류학회지
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• 제46권5호
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• pp.741-759
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• 2022

This study examines the effect of live commerce characteristics on consumption behavior mediated by presence. As contactless shopping has become the new normal, live commerce is emerging as an innovative communication service between consumers and sellers. We examine the role of interaction and streamers' attributes on sharing and purchase intention by mediating social presence and telepresence. A web-based experiment was conducted to test our hypotheses. The data of 267 participants were analyzed using SPSS 23.0 and AMOS 21.0. The results showed that the Streamer-Consumer interaction had a positive effect on social presence and telepresence. By contrast, the Consumer-Consumer interaction had no significant effect on social presence and telepresence. We further found that streamer trustworthiness had a positive effect on both social presence and telepresence, while streamer attractiveness had a positive effect only on telepresence. Thus, social presence and telepresence positively influenced sharing and purchase intention. Overall, these findings illustrate that the Streamer-Consumer interaction and streamer trustworthiness are vital characteristics that lead to higher levels of presence using live commerce. Several academic and managerial implications are suggested based on these results.

• 한국프랜차이즈경영연구
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• 제15권2호
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• pp.17-37
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• 2024

Purpose: This study used the SOR model to analyze the impact of live commerce's modified livecommercescape factors (interactivity, presence, playfulness, convenience, and broadcaster characteristics) on repurchase intention through usefulness and flow. Research design, data, and methodology: 1,149 respondents with live commerce purchase experience were collected through an online survey, and the collected data was analyzed with SPSS 25.0 and SmartPLS 4.0 statistical package programs. Results: Presence and playfulness were found to have the highest influence on flow and usefulness. In particular, Presence and broadcaster characteristics were found to be the factors that had the greatest influence on flow. Playfulness was found to have the greatest impact on usefulness, and two-way communication was found to have the lowest influence among the five servicescape factors. Broadcaster characteristics also affect flow but not usefulness, and convenience only affects usefulness and does not affect flow. Flow shows results that affect usefulness and repurchase intention. Conclusion: Our findings provide a richer understanding of causal relationships within the SOR framework, demonstrating that broadcaster characteristics, two-way communication, presence, and playfulness can influence flow, perceived usefulness, and, consequently, consumer purchasing behavior.

• 보건의료산업학회지
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• 제13권3호
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• pp.127-136
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• 2019

Objectives: This study examined the determinants of quality of life, depending on the presence or absence of asthma in adults, based on secondary wave data. Methods: Among the 21,724 people participating in the 6th Korea National Health and Nutrition Examination Survey as it was conducted from the first to third period, 495 participants who were aged 19 or older and responded to the question of the presence or absence of asthma were included in the final analysis. Demographic characteristics were examined using the SPSS/WIN 23.0 software tool for analysis of complex sample survey data. Health-related characteristics were presented using descriptive and multivariate analysis of data. Rao_Scott ${\chi}^2$ was used for the analysis of differences in quality of life, and multiple regression analysis of complex sample survey data was used to analyze factors affecting quality of life. Results: The variable factors negatively influencing quality of life were aging, cognition of their ill health, and limited activities. Conclusions: Based on the analysis, the study suggests that practical and ongoing nursing intervention proposals to improve the quality of life of asthmatic patients should be implemented not only for physical limitations and aging but also for psychological factors that reflect subjective health statuses.

• Bulletin of the Korean Chemical Society
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• 제14권1호
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• pp.107-109
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• 1993

Non-enzymatic glycosylation and fragmentation of collagen molecule were investigated by irradiating Ultraviolet A(UV-A) with or without scavengers of reactive oxygen species (ROS) in the presence of glucose. Non-enzymatic glycosylation was increased by UV-A at high concentration of glucose. It was reduced in the presence of the scavengers of superoxide radical and singlet oxygen, but not reduced in the presence of hydroxy radical scavenger. Fragmentation of collagen was increased by UV-A, but it was decreased in the presence of all ROS scavengers tested. Superoxide radical and singlet oxygen produced by autoxidation of glucose without UV-A may encounter the initial phase of glycosylation. Data presented here suggest that UV-A affects only on the fragmentation process, but all ROS except hydroxy radical act on both processes. It appears that hydroxy radical does not act on the glycosylation process.

• Journal of the Korean Statistical Society
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• 제26권3호
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• pp.319-332
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• 1997

The application of multivariate linear rank statistics to data with item nonresponse is considered. Only a modest extension of the complete data techniques is required when the missing data may be thought of as a random sample, and an appropriate modification of the covariances is derived. A proof of the asymptotic multivariate normality is given. A review of some related results in the literature is presented and applications including longitudinal and repeated measures designs are discussed.