• 정보처리학회논문지D
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• 제16D권6호
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• pp.945-960
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• 2009

본 연구의 목적은 첫째, 인터넷전화(Voice over Internet Protocol)의 사용자 수용에 미치는 결정요인을 정의하고, 둘째, 수용 이론들의 통합모형인 UTAUT를 기저모형으로 하여, 성과기대감, 사회적 영향, 노력기대감, 사용촉진조건, 행위의도와 사용행위 등의 잠재변수 간의 복합적인 인과관계를 검증하는 것이다. 셋째, 비용기대감 변수를 새롭게 정의하여 연구가설에 포함하였고, 각 변수들 간의 경로에 영향을 주는 조절변수로서 사용자 연령, 성별, 경험기간의 조절효과를 분석하였다. 또한, VoIP의 실제 사용자 641명을 표본 조사함으로써, 행위의도와 사용행위 변수 간의 개념적 차이를 명확히 구분하여 보다 정확한 분석 결과의 향상을 도모하였다. 사용자 수용에 대한 기존 연구들은 사용행위 변수를 검증할 때, 실제 사용자뿐만 아니라 긍정적인 행위의도를 가진 미래의 잠재적 사용자를 포함시키는 사례가 많았다. 분석 결과, 제시한 모든 연구가설이 채택되었으며, 조절효과에서 연령이 성과기대감, 사회적 영향과 행동의도 간에, 경험기간은 사용촉진조건, 행위의도와 사용행위 간에 정의 관계가 성립하였다.

• 한국자원식물학회지
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• 제27권6호
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• pp.707-713
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• 2014

This study examined the inflammatory reaction effects of Allium victorialis var. platyphyllum in vivo at the time of a lipopolysaccharide (LPS) shock in rats, and in vitro in cultured Raw 264.7 cells, with the aim of facilitating the development of a new anti-inflammatory medicine. Plasma concentrations of interleukin (IL)-$1{\beta}$, IL-6, tumor necrosis factor ${\alpha}$ (TNF-${\alpha}$), and IL-10 in rats peaked 5 h after LPS treatment in all experimental groups, with those of IL-$1{\beta}$, IL-6, and TNF-${\alpha}$ being significantly lower in all animals treated with A. victorialis than in the control group at that time point. Conversely, the plasma concentration of IL-10 was higher in the rats treated with 300 mg/kg A. victorialis extract than in the control group at both 2 and 5 h after LPS treatment. Concentrations of IL-$1{\beta}$ and IL-6 in the liver of rats treated with A. victorialis extract were significantly lower than those of the saline-treated control group. However, the liver concentrations of TNF-${\alpha}$ and IL-10 did not vary significantly between the four animal groups. Similarly, concentrations of IL-$1{\beta}$, IL-6, and TNF-${\alpha}$ obtained from cultured Raw 264.7 macrophages were lower in all of the A.-victorialis-extract-treated groups than in the control group. Although the concentration of IL-10 in the A.-victorialis-extract-treated groups tended to be greater than in the control group, the differences between groups were not statistically significant. Together the findings of this study suggest that A. victorialis var. platyphyllum contains functional substances that are involved in inflammatory reactions.

• 패션비즈니스
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• 제19권2호
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• pp.69-84
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• 2015

The objective of this study is to investigate the intention to adopt smart wear, based on extended UTAUT model. We examined the effects of performance expectancy (PE), effort expectancy (EE), hedonic motivation (HE), social influence (SI), facilitating conditions (FC), and price value (PV) on the intended adoption of smart watch and smart shoes, respectively. In addition, moderating effects of gender, age, and innovation resistance were examined. An online survey was conducted, comprised of 2030 consumers who were aware of smart watch or smart shoes. In total, 393 responses were analyzed. About 50.4% were male, and 44.8% were in their 20's. An exploratory factor analysis generated five factors - PE & HM, EE, SI, FC, and PV- which were employed as independent variables in the multiple regression models. PE & HM, PV, and SI influenced on the intention to use both smart devices. FC showed the significant effect only on the intention to adopt the smart watch. In terms of gender differences, SI and PV were the important predictors of the intention to adopt the smart watch in the female group only. With respect to age difference, SI was very effective in explaining the intention of individuals in their 30's to adopt smart wear. Among the low innovation resistance group, SI was significant predictor, while PE & HE and PV were significant among the high resistance group. The findings provide useful information about the possibility of the adoption of smart wear, and new insight into market segmentation.

• 정보보호학회논문지
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• 제31권5호
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• pp.951-958
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• 2021

정보 자산에 대한 사이버 위협이 증가하면서 위협과 관련된 정보들을 빠르게 공유하는 것이 무엇보다 중요해졌다. 본 연구에서는 국내외 사이버 위협 정보의 공유 현황을 살펴보고 시장에서 공유되고 있는 위협 지표별 우선순위를 도출하여 위협 지표의 중요도를 평가하였다. 분석은 AHP 기법을 활용하였으며, 공격자 및 감염자 지표, 역할 지표, 악성 파일 지표, 기법 및 전파 지표의 네 가지 평가기준과 해당 기준별 세부항목에 대한 쌍대비교를 통해 이루어졌다. 분석 결과 상위 평가 기준 사이에서는 악성 파일 지표가 가장 중요한 것으로 확인되었으며, 각 기준별 세부 항목간 비교에 있어서는 공격자 및 감염자 지표의 경우 감염자 IP가, 역할 지표의 경우 C&C 정보가, 악성 파일 지표의 경우 악성코드 지표가, 기법 및 전파 지표의 경우 스미싱 관련 지표가 보다 중요한 요소로 확인되었다. 이와 같은 결과는 위협 정보에 대한 소비자의 선호도와 정보 제공자의 기여도를 판단하는 자료로서 정보 공유 활성화에 도움이 될 수 있을 것이다.

• Molecules and Cells
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• 제44권9호
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• pp.647-657
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• 2021

As a pancreatic inflammatory marker, regenerating islet-derived protein 3A (Reg3A) plays a key role in inflammation-associated pancreatic carcinogenesis by promoting cell proliferation, inhibiting apoptosis, and regulating cancer cell migration and invasion. This study aimed to reveal a novel immuno-regulatory mechanism by which Reg3A modulates tumour-promoting responses during pancreatic cancer (PC) progression. In an in vitro Transwell system that allowed the direct co-culture of human peripheral blood-derived dendritic cells (DCs) and Reg3A-overexpressing/ silenced human PC cells, PC cell-derived Reg3A was found to downregulate CD80, CD83 and CD86 expression on educated DCs, increase DC endocytic function, inhibit DC-induced T lymphocyte proliferation, reduce IL-12p70 production, and enhance IL-23 production by DCs. The positive effect of tumour-derived Reg3A-educated human DCs on PC progression was demonstrated in vivo by intraperitoneally transferring them into PC-implanted severe combined immunodeficiency (SCID) mice reconstituted with human T cells. A Reg3A-JAK2/STAT3 positive feedback loop was identified in DCs educated with Reg3A. In conclusion, as a tumour-derived factor, Reg3A acted to block the differentiation and maturation of the most important antigen-presenting cells, DCs, causing them to limit their potential anti-tumour responses, thus facilitating PC escape and progression.

• Plant Breeding and Biotechnology
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• 제5권2호
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• pp.123-133
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• 2017

AP2/EREBP gene family consists of transcription factor genes with a conserved AP2 DNA-binding domain and is involved in various biological processes. AP2/EREBP gene families were identified through genome-wide searches in five Cucurbitaceae species including cucumber, wild cucumber, melon, watermelon, and bitter gourd, which consisted of more than 100 genes in each of the five species. The gene families were further divided into five groups including four subfamilies (ERF, DREB, AP2 and RAV) and a soloist group. Among the subfamilies, DREB subfamily which is known to be related to abiotic stress response was more analyzed and a total of 25 genes were identified as Cucurbitaceae homologues of Arabidopsis CBF/DREB1 genes which are important for abiotic stress-response and tolerance. In silico expression profiling using RNA-Seq data revealed diverse expression patterns of cucumber AP2/EREBP genes. AP2/EREBP gene families identified in this study will be valuable for understanding the stress response mechanism as well as facilitating molecular breeding in Cucurbitaceae crops.

• 동의생리병리학회지
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• 제33권4호
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• pp.191-197
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• 2019

This study aims to evaluate the effects of the root bark of Morus alba (RMA) on the regulation of the Hippo-YAP pathway. Hippo-YAP signaling is a critical regulator in controlling organ size and tissue homeostasis. Hippo, the serine/threonine kinase phosphorylate the LATS. Phosphorylated LATS then phosphorylates and inactivates the YAP and TAZ, which are two closely related transcriptional co-activator. Here we report RMA activates the Hippo signaling, thereby inhibits the YAP/TAZ activity. First, we examine the cytotoxic effects of RMA by MTT assay. RMA was cytotoxic at concentrations higher than $50{\mu}g/ml$ in HEK293A cells. The reporter gene assay was performed to measure the activity of TEAD, a key transcription factor that controls cell growth and proliferation. RMA significantly suppressed the luciferase activity. By phos-taq gel shift assay, and western blotting, we showed that RMA enhanced the phosphorylation of YAP in wild type cells, but not in LATS1/2 knock out cells, which means RMA activates classical Hippo pathway. RMA induced the cytoplasmic sequestration of YAP. RMA also suppressed the mRNA expression of CTGF and CYR61; the two major YAP dependent genes. Taken together, RMA is considered to be a good candidate for proliferative disease such as cancer, by facilitating cell death through activating the Hippo signaling pathway.

• 한국ITS학회 논문지
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• 제20권1호
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• pp.40-53
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• 2021

공유 전동킥보드는 기존 'station 기반의 공유 교통서비스에 비해 편리한 dockless 방식으로 제공되어 이용이 급격하게 증가하고 있다. 이에 따라 교통사고, 보행환경 저해 등 새로운 도시문제가 발생하고 있다. 본 연구에서는 서울시를 대상으로 최근 급격하게 성장하고 있는 공유전동킥보드의 이용 특성을 분석하고, 음이항 회귀모형을 통해 서울시 집계구 단위의 공유 전동킥보드 이용수요에 영향을 미치는 요인에 대하여 규명하였다. 이용특성 분석결과 평균 이용거리는 1.5km, 이용시간은 9.4분, 이동속도는 10.3km/h로 나타났다. 공유 전동킥보드의 이용수요에 대한 영향요인을 살펴보면, 인구지표, 교통시설지표, 토지이용지표, 기상지표가 통계적으로 유의하게 영향을 미치는 것으로 분석되었다. 본 연구의 결과는 향후 공유 전동킥보드의 이용수요가 많은 지역에 대한 효율적인 운영 및 이용 활성화를 위한 교통정책 수립의 기초자료로 활용될 수 있을 것으로 기대된다.

• 의학교육논단
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• 제23권1호
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• pp.46-55
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• 2021

Since the emergence of coronavirus disease 2019 (COVID-19), medical schools have experienced a sudden, full-scale transition to online classes. As the COVID-19 pandemic continues, it is important to evaluate current educational programs and to assess their implications. This study explored perceptions of online classes and learning behavior among medical students. Twenty preclinical medical students were interviewed in focus groups for 2 months. They generally expressed positive perceptions about online classes, and in particular, positively assessed the ability to lead their individual lifestyles and study in comfortable environments with fewer time and space constraints. Students thought that the online environment provided a fair chance of facilitating positive interactions with the professor and considered communication with the professor to be an important factor only when it was related to the class content or directly helped with their grades and careers. Students also had negative views, such as feeling uncertain when they could not see their peers' learning progress and assess themselves in comparison and feeling social isolation. Learning behaviors have also changed, as students explored their learning styles and adapted to the changed learning environment. Students expanded their learning by using online functions. However, students sometimes abused the online class format by "just playing" the lecture while not paying attention and relying on other students' lecture transcripts to study. The results of this study are hoped to provide a useful foundation for future research on online class-based teaching and learning.

• Steel and Composite Structures
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• 제49권2호
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• pp.143-159
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• 2023

Recently, the design of scaffolding systems has garnered considerable attention due to the increasing number of scaffold collapses. These incidents arise from the underestimation of imposed loads and the site-specific conditions that restrict the application of lateral restraints in scaffold assemblies. The present study is committed to augmenting the buckling resistance of vertical support members, obviating the need for supplementary lateral restraints. To achieve this objective, experimental and computational analyses were performed to assess the axial load buckling capacity of steel props, composed of two hollow steel pipes that slide into each other for a certain length. Three full-scale steel props with various geometric properties were tested to construct and validate the analytical models. The total unsupported length of the steel props is 6 m, while three pins were installed to tighten the outer and inner pipes in the distance they overlapped. Finite Element (FE) modeling is carried out for the three steel props, and the developed models were verified using the experimental results. Also, theoretical analysis is utilized to verify the FE analysis. Using the FE-verified models, a parametric study is conducted to evaluate the effect of different inserted pipe lengths on the steel props' axial load capacity and lateral displacement. Based on the results, the typical failure mode for the studied steel props is global elastic buckling. Also, the prop's elastic buckling strength is sensitive to the inserted length of the smaller pipe. A threshold of minimum inserted length is one-third of the total length, after which the buckling strength increases. The present study offers a prop with enhanced buckling resistance and introduces an equation for calculating an equivalent effective length factor (k), which can be seamlessly incorporated into Euler's buckling equation, thereby facilitating the determination of the buckling capacity of the enhanced props and providing a pragmatic engineering solution.