• 경영과정보연구
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• 제31권2호
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• pp.143-172
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• 2012

기업과 소비자간 전자 상거래 시장이 급속히 성장하고 있으나 많은 전문가들은 아직도 그 잠재력을 충분히 발휘하지 못하고 있다고 주장한다. 이에 대한 이유로 온라인 쇼핑환경이 지니는 인간적 사회적 요소의 부재를 들고 있다. 온라인 쇼핑은 전통적인 면대면 상거래에 비해 보다 비인적이며 익명성이 강해 인간적인 온정과 사회성이 부족하다. 본 연구에서는 전통적 상거래에 비해 온라인 쇼핑이 가지는 태생적 한계인 면대면 사회적 상호작용을 대신할 수 있는 개념으로 사회적 실재감을 도입하여 사회적 실재감의 선 후행변수간의 관계를 규명하고자 하였다. 이러한 연구 목적을 달성하기 위하여 본 연구주제와 관련 있는 마케팅, 심리학, 커뮤니케이션 연구분야의 연구결과들을 고찰하였으며, 이를 기반으로 하여 연구모형을 제시하였다. 제시된 연구모형을 검증하기 위하여 자기 보고식 설문지를 사용하여 자료를 수집하였다. 본 설문의 응답자들은 최소 5회 이상 인터넷 구매를 경험한 소비자들로 구성하였는데, 이는 사회적 실재감에 대한 지각은 인터넷 쇼핑몰과의 잦은 접촉이 있어야만 생길 수 있는 지각으로 판단하였기 때문이다. 실증분석 결과는 다음과 같다. 먼저 쇼핑몰의 맞춤화 노력은 지각된 사회적 실재감에 유의한 영향을 미치는 것으로 나타났다. 둘째, 쇼핑몰의 반응성 역시 지각된 사회적 실재감에 유의한 영향을 미치는 것으로 나타났다. 따라서 쇼핑몰은 고객의 요구에 다양한 방법으로 신속하고 성실하게 반응함으로써 사회적 실재감을 높일 수 있다. 셋째, 지각된 게시판 활동성은 사회적 실재감에 영향을 미치는 것으로 나타났다. 쇼핑몰 운영자는 자사 게시판을 적극적으로 활성화하여 소비자의 사회적 실재감을 높일 수 있을 것이다. 마지막으로 지각된 사회적 실재감은 쇼핑몰 신뢰와 즐거움에 영향을 미치고 쇼핑몰 신뢰와 즐거움은 쇼핑몰 충성도에 유의한 영향을 미치는 것으로 나타났다. 이러한 결과는 기존 온라인 쇼핑에 관한 연구의 중심이 되고 있는 쇼핑몰 충성도와 신뢰 형성에 사회적 실재감이 중요한 영향요인임을 의미하는 것으로 쇼핑몰 신뢰와 충성도를 위한 새로운 전략적 시사점을 제공하고 있다고 볼 수 있다.

• 수산해양교육연구
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• 제28권1호
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• pp.59-68
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• 2016

For comparison of tetracycline-resistant ($Tc^R$) genes, we obtained 21 and 14 $Tc^R$ Staphylococcus spp. from marine environment and human patient, respectively. Although all isolates from human were identified as Staphylococcus aureus, higher proportion of $Tc^R$ isolates (12 out of 14) from human were utilizing tet(M) gene compared to that of $Tc^R$ isolates (6 out of 21) from marine environment. Additionally, collaborated utilization of tet(M) and erm(A) in $Tc^R-Em^R$ S. aureus in human patient, but not in $Tc^R$ Staphylococcus spp. isolates from marine environment was also characterized. Based on the nucleotide sequence of transposon related to $Tc^R$ gene, we confirmed the origin of tet(M) gene in $Tc^R$ Staphylococci isolated from marine environments and human are derived from Tn916/1545-like and Tn5801 transposon, respectively. It is the first report showing the presence of Tn5801 in all $Tc^R$ S. aureus carrying tet(M) in human patient. Alignment of the fully sequenced tet(M) from marine environmental isolates was also agreed with the determined transposons by showing the genomic mosaic structure composed with three genomic parts from Tn916/1545 and unknown transposons. Genetic characteristics of these tet(M) in environmental isolates were similar to each other but different from those in isolates from human showing only tet(M) from Tn916/5801 type. It may imply the presence of less dramatic communication of antibiotic resistant genes between Staphylococci isolated from marine environment and human.

• 대한임베디드공학회논문지
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• 제15권1호
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• pp.35-42
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• 2020

In this paper, we propose a method to keep the robot at a distance of 30 to 45cm from the user in consideration of each individual's minimum area and inconvenience by using a 2D LiDAR sensor LDS-01 as the secondary sensor along with a QR code. First, the robot determines the brightness of the video and the presence of a QR code. If the light is bright and there is a QR code due to human's presence, the range of the 2D LiDAR sensor is set based on the position of the QR code in the captured image to find and follow the correct target. On the other hand, when the robot does not recognize the QR code due to the low light, the target is followed using a database that stores obstacles and human actions made before the experiment using only the 2D LiDAR sensor. As a result, our robot can follow the target person in four situations based on nine locations with seven types of motion.

• Parasites, Hosts and Diseases
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• 제38권2호
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• pp.103-106
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• 2000

It is well known that the cysteine proteases in excretory-secretory product (ESP) of Paragonimus westermani newly excysted metacercariae (PwNEM) are capable of degrading IgG in vitro. Recent evidence suggests that the IgG-coated surface, such as found on parasites, is one of the most effective physiologic stimuli for granulocyte activation. Therefore, this study was designed to investigate the effect of excretory-secretory product (ESP) of PwNEM on superoxide production of granulocytes stimulated with IgG The 96-well plates were coated with human IgG (0, 10, 30, $100{\;}\mu\textrm{g}/ml$) in the absence or presence of ESP. When granulocytes were incubated in the wells coated with human IgG in the presence of ESP, the level of superoxide production of granulocytes was reduced to about 90% when compared to the cells incubated in the wells coated with IgG alone. This inhibitory effect of the ESP on IgG-induced superoxide production of granulocytes was concentration-dependent. These results suggest that ESP secreted by PwNEM may be important in the control of effector functions of granulocytes stimulated with IgG in human paragonimiasis.

• BMB Reports
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• 제36권4호
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• pp.367-372
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• 2003

The stability of four hemoglobins (Hb) in dimer forms (low concentration) were investigated by the kinetics of denaturation. The rate constants of denaturation were obtained by variation of 280 nm absorption versus time in 10 mM Tris-HCl, 10 mM EDTA, pH 8.0 at $45^{\circ}C$ in the absence and presence of 0.5 M ethanol, dimethyl sulfoxide (DMSO), formamide, and glycerol. The results show the trend of rate constants in different co-solvents in the following order: chicken hemolysate < human hemolysate and chicken Hb D < chicken Hb A. The buried surface area was calculated for Hb samples in the absence of cosolvents. Accordingly, the trend points out that: chicken Hb D > chicken Hb A > human Hb A. These results suggest that both chicken hemolysate and chicken Hb D are relatively more stable than human and chicken Hb A, respectively. However, the denaturation rate constants of Hb in different co-solvents have designated the following order: ethanol > DMSO > formamide > glycerol. As a matter of fact, this phenomenon is an indication of an increase in the denaturation capacity (DC) and hydrophobicity, and a decrease in the surface tension of the solution in the preceding co-solvents.

• Journal of Periodontal and Implant Science
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• 제23권2호
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• pp.228-242
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• 1993

Some therapeutic agents and medicaments may lead to pathologic changes in the gingival tissue, especially on the cultured human gingival fibroblasts. The purpose of this study was to investigate on the effect of diphenylhydantoin, retinoic acid to the human gingival fibroblast. Human gingival fibroblasts were cultured from the healthy gingiva of patients with orthodontic patients. Gingival fibroblasts were trypsinized and transferred to the wells of 96 well microtest plates. Next day, the medium was removed, fibroblasts were washed with HBSS, and the washed cells were cultured in growth medium added 5 or $10{\mu}g/ml$ of diphenylhydantoin, $10^{-5}M$, $10^{-6}M$ and $10^{-7}M$ of retinoic acid and glycyrrhetinic acid. The passage number of cultured fibroblasts were fifth and eighth. The cell morphology was examined by inverted microscope, the cell number was counted by hemocytometer, and cell activity was measured by the growth and proliferatiton assay using MTT assay. The fifth experiments were performed and statistical significance was measured by ANOVA. The cell morphology in the presence of retinoic acid was round irrespective of the presence of diphenylhydantoin and glycyrrhetinic acid(Fig 2-6). The proliferation of cells was not changed by diphenylhydantoin(Table 1). The cell activity showed the tendency to increase at the concentration of $10{\mu}$'/, of diphenylhydantoin (Table 2). The cell activity in the presence of retinoic acid glycyrrhetinic acid was decreased, and the increased cell activity by diphenylhydantoin was decreased by retinoic acid and glycyrrhetinic acid at the concentration of $10^{-7}M$(Table 3-5). These results suggested that the increased cell activity by diphenylhydantoin might be modulated by retinoic acid and glycyrrhetinic acid.

• Journal of Periodontal and Implant Science
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• 제24권1호
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• pp.98-108
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• 1994

Gingival hyperplasia is frequently associated with the long-term use of phenytoin for control of convulsive disorder. The purpose of this study was to investigate on the effects of lipopolysaccharides (LPS), ursolic acid and oleanolic acid to phenytoin-induced cell activity in human gingival fibroblast. Human gingival fibroblasts were cultured form the healthy gingiva of orthodontic patients. Gingival fibroblasts were trypsinized and transferred to the weels of microtest plates. Fibroblast were cultured in growth medium added $5{\mu}g/ml$ of phenytoin, $5{\mu}g/ml$ of LPS, $10^{-7}M$ of ursolic acid and oleanolic acid. The passage number of cultured fibroblasts were fifth and eight. Cell morphology was examined by inverted microscope and the cell activity was measured by proliferation assay. Ursolic acid significantly modulated cell morphology into globular shape at the concentrantion of $10^{-7}M$ in the presence of phenytoin and LPS, and the cell activity was significantl decreased by ursolic acid or oleanolic acid regardless of the presence of phenytoin and LPS. These results suggested that the increased phenytoin-induced cell activity might be modulated by ursolic acid regardless of the presence of phenytoin and LPS. These results suggested that the increased phenytoin-induced cell activity might be modulated by ursolic acid or oleanolic acid. Further study is needed to clarify their toxicological effects on cellular modulation and mRNA expression change.

• Journal of Periodontal and Implant Science
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• 제23권3호
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• pp.622-634
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• 1993

Gingiva is remarkly sensitive to certain drugs. Especially, long term use of phentoin, dihydropyrydine (including nifedipine), cyclosporin and other drugs can be lead to pathologic changes in gingival tissue, especially in terms of proliferation of epithelium and connective tissue. Recent study in terms of proliferation of epithelium and connective tissue. Recent study is focused on the inhibition of drug-induced gingival hyperplasia by using medicaments. The purpose of this study was to investigate on the pharmacological effects of nifedipine, retinoic acid and glycyrrhetini acid to the activity in human gingival fibroblast. Human gingival fibroblasts were cultured from the healthy gingiva of orthodontic patients. Gingival fibroblasts were trypsinized and cultured in growth medium added $5{\mu}g/ml$ of nifedipine, $10^{+7}M$ of retinoic acid and glycyrrhetinic acid. The passage number of cultured fibroblasts were between fifth and eighth. The cell morphology was examined by inverted microscope and the cell acitivity was measured by the MTT assay. Nifedipine at the concentration of $5{\mu}g/ml$ was revealed significantly effective to increase the cell activity and lipopolysaccharide was cofactor to increase cell activity in the presence of nifedipine. However, retinoic acid was significantly effective on the globular change of cell morphology and loss of cell process regardless of the presence of nifedipine and LPS. Cell activity was significantly decreased by the glycyrrhetinic acid at the concentration of $10^-M$ regardless of the presence of nifedipine and LPS. These results suggested that the increased cell activity by nifedipine might be modulated by retinoic acid and glycyrrhetinic acid. Further study is needed to clarify on their toxicological effects during cellular modulation and mRNA expression change.

• Korea Journal of Cosmetic Science
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• 제1권1호
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• pp.1-9
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• 2019

The identification of compounds with anti-senescence activity in cell culture system is a first step in aging research. Given that pyruvate can be used energy source by conversion to acetyl-CoA in mitochondria, and protects cultured cell from various stress-induced cell damage and cell death, synthetic media (e.g., DMEM) often includes 1 mM pyruvate, which is very higher than the pyruvate concentration in human blood (approximately 30 ��M). However, the use of medium containing high concentration of pyruvate is not suitable for screening anti-senescence compounds, because pyruvate also protects against the cellular senescence of primary human dermal fibroblasts (NHDFs) through NAD+ generated during conversion to lactate. In this study, four extracts, i.e., Sprouted seed and fruit complex, Poncirus trifoliata fruit extract, Jaum balancing complex, and Prunus mume extract were used for evaluation of different anti-senescence effect in the absence or presence of 0.1 mM pyruvate, similar to the physiological pyruvate concentration. The senescence in NHDFs cultured with DMEM in the presence of 0.1 mM pyruvate (approximately the physiological concentration in human blood) is accelerated, as observed in pyruvate deprivation conditions. The cytotoxicity of the Poncirus trifoliata fruit extract was protected by pyruvate, and Jaum balancing complex and Prunus mume extract had anti-senescence activity in the presence of 0.1 mM pyruvate, but not in the absence of pyruvate. Given that pyruvate is a powerful protector against both cytotoxicity and cellular senescence, the screening of candidate agents for anti-senescence in high pyruvate conditions using an in vitro cell culture system is not valid. Therefore, we recommend the use of a low concentration of pyruvate to evaluate the anti-senescence effects of candidates, which is more similar to in vivo aging conditions than excessive stress-induced senescence models, to exclude the effect of excessive pyruvate in vitro.

• 한국정보시스템학회지:정보시스템연구
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• 제32권1호
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• pp.23-51
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• 2023

Purpose: Live commerce is a new type of electronic commerce in combination with live streaming services. It is expected to increase virtual presence in the context of online shopping by overcoming a lack of social interactions between sellers and buyers which have been raised as a limitation in electronic commerce. Drawing on the studies of communication media, this study examines how live commerce contributes to the increase of virtual presence which consists of telepresence and social presence. Telepresence refers to a buyer's perception that he or she is present at the physical shopping mall during live shopping streaming whereas social presence refers to a buyer's perception of social interaction with a seller which is human warm, social, sensitive, and personal. In this study, we verify key determinants of virtual presence and its consequences. More specifically, this study proposes virtual presence contributes to the increase of buyers' trust in products and further purchase intentions. Furthermore, we verify influential factors of virtual presence from the technical and influencer perspectives of live commerce. Design/methodology/approach: To test the proposed hypotheses, the partial least squares (PLS) analysis is conducted with a total of 250 data collected on users with experience in the TaoBao live streaming shopping platform. Findings: The results show that first, telepresence and social presence are increased by visibility, media richness and attractiveness in the context of live shopping streaming. Second, buyers' trust in product trust and purchase intentions are positively influenced by telepresence and social presence. Finally, buyers' trust in product has a direct, positve effect on their purchase intentions. Overall, the findings offer new insights into the studies of electronic commerce by introducting the concepts of virtual presence and media richness from the literature of communication media in the field of live commerce.