• The Korean Journal of Physiology and Pharmacology
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• 제21권2호
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• pp.161-168
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• 2017

Understanding the crosstalk mechanisms between perivascular cells (PVCs) and cancer cells might be beneficial in preventing cancer development and metastasis. In this study, we investigated the paracrine influence of PVCs derived from human umbilical cords on the proliferation of lung adenocarcinoma epithelial cells (A549) and erythroleukemia cells (TF-$1{\alpha}$ and K562) in vitro using $Transwell^{(R)}$ co-culture systems. PVCs promoted the proliferation of A549 cells without inducing morphological changes, but had no effect on the proliferation of TF-$1{\alpha}$ and K562 cells. To identify the factors secreted from PVCs, conditioned media harvested from PVC cultures were analyzed by antibody arrays. We identified a set of cytokines, including persephin (PSPN), a neurotrophic factor, and a key regulator of oral squamous cell carcinoma progression. Supplementation with PSPN significantly increased the proliferation of A549 cells. These results suggested that PVCs produced a differential effect on the proliferation of cancer cells in a cell-type dependent manner. Further, secretome analyses of PVCs and the elucidation of the molecular mechanisms could facilitate the discovery of therapeutic target(s) for lung cancer.

• 영재교육연구
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• 제22권1호
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• pp.61-85
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• 2012

음악영재성 판별에서 부모의 관찰은 잠재된 영재성에 관한 정보를 제공하기에 중요하다. 또한 부모관찰정보의 타당도와 신뢰도는 후속되는 판별 전 과정의 타당성 확보에 영향을 미친다. 이러한 중요성에도 불구하고 국내 교사관찰추천제 및 음악영재성 판별모형에 투입되는 부모관찰정보의 타당성 여부에 관한 연구는 아직까지 없었다. 그러므로 이 연구는 음악(국악) 영재성 선별을 위한 부모관찰정보지(2차)의 타당화를 위하여 수행되었다. 나아가 음악(국악) 영재성 판별의 내실화 및 체계화를 도모하기 위하여 수행되었다. 부모관찰정보지(2차)의 타당도 검증을 위하여 탐색적 요인분석 및 확인적 요인분석을 활용하였다. 그 결과, 부모관찰정보지(2차)의 최종 40문항을 수렴할 수 있었고 나아가 음악(국악) 영재성의 심리학적 구인을 확인할 수 있었다. 또한 부모관찰정보지(2차)에 대한 내적 일관성 신뢰도 추정 결과, 높은 신뢰도 수준(내재적 특성 문항 $r$=.939, 외재적 환경 특성 문항 $r$=.887)을 확보할 수 있었다. 이 연구의 타당화 결과는 부모관찰정보지(2차)가 음악(국악) 영재성 선별을 위한 타당한 검사도구로서 영재 판별 현장에 즉시 투입 가능함을 반영해준다.

• 디지털융복합연구
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• 제11권12호
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• pp.237-243
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• 2013

기업은 시작과 동시에 계속기업을 영위하면서 사회적 책임도 가지게 된다. 하지만 최근 기업의 평균수명이 점점 단축되고 있으며 기업환경 또한 급격하게 변화하고 있다. 따라서 본 연구에서는 글로벌 기업의 장수요인 분석을 통하여 기업의 장수, 즉 계속기업의 해답을 얻고자 하였다. 지멘스와 듀폰의 두 거대 글로벌기업의 장수요인을 분석해 본 결과 그 요인은 사업포트폴리오 변화, 위험관리, 지속적 연구개발, 신뢰경영, 친환경경영등의 요인이 설명되었다. 이는 지속적 내, 외부 환경 분석 및 핵심역량 강화를 통한 책임경영의 구현이 곧 장수경영의 핵심으로 나타나고 있다.

• 상하수도학회지
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• 제35권3호
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• pp.197-204
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• 2021

In MBR, extracellular polymeric substance (EPS) is known as an important factor of fouling; soluble EPS (sEPS) affects internal contamination of membrane, and bound EPS (bEPS) affects the formation of the cake layer. The production of EPS changes according to the composition of influent, which affects fouling characteristics. Therefore, in this study, the effects of the F/M ratio on the sEPS concentration, bEPS content, and fouling were evaluated. The effects of F/M ratio on the amount and composition of EPS were confirmed by setting conditions that were very low or higher than the general F/M ratio of MBR, and the fouling occurrence characteristics were evaluated by filtration resistance distribution. As a result, it was found that the sEPS increased significantly with the increase of the F/M ratio. When the substrate was depleted, bEPS content decreased because bEPS was hydrolyzed into BAP and seemed to be used as a substrate. In contrast, when the substrate is sufficient, UAP (utilization-associated products) was rapidly generated in proportion with the consumption of the substrate. UAP has a relatively higher Protein/Carbohydrate ratio (P/C ratio) than BAP, and this means, it has a higher adhesive force to the membrane surface. As a result, UAP seems like causing fouling rather than BAP (biomass-associated products). Therefore, R_f (Resistance of internal contamination) increased rapidly with the increase of UAP, and R_c (Resistance of cake layer) increased with the accumulation of bEPS in proportion, and as a result, the fouling interval was shortened. According to this study, a high F/M ratio leads to an increment in UAP generation and accumulation of bEPS, and by these UAP and bEPS, membrane fouling is promoted.

• 한국산학기술학회논문지
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• 제15권5호
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• pp.3336-3344
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• 2014

본 연구의 목적은 소규모 응집침전모듈의 개발 및 lab-scale 테스트를 통한 실증이다. 최근 하수처리율이 높아짐에 따라 비점오염원 관리에 대한 관심이 높아지고 있어 소규모 처리장치 개발의 필요성이 증대되고 있다. 본 연구의 응집침전모듈은 응집공정 이후 외부 영역에서 선회류를 통한 플럭(floc)의 추가 성장 및 미세 플럭 수의 감소, 내부 침전 영역에서 수직 수평류 복합침전방식을 통한 침전효율 증대로 효과적인 고액분리가 가능토록 하였다. 응집침전모듈은 수직 수평류 복합침전 방식을 통해 재래식침전조에 비해 같은 체적에서 침전면적 및 표면부하율을 4.4배 증가시킬 수 있었다. 본 연구에서 외부 및 내부 침전 영역에서의 선회류 형성 유지와 내부 침전영역에서의 균등한 유량분배를 본 공정의 중요한 설계인자로 선정하였고, 이의 도출을 위해 유체유동해석 모델인 FLUENT를 이용하였다. 선회류 유동경향 모사를 통해 유입속도, 외부조의 규격, 하부콘호퍼 깊이 등을 결정하였고 속도분포 및 유량분배 해석을 통해 유출공 직경과 개수, 유출홀 직경 등 내부 침전영역의 세부 규격을 도출하였다. $60{\ell}/hr$규모의 파일럿 테스트 결과 20분의 체류시간 동안(표면부하율은 $37.3m^3/m^2$일)탁도 300~800 NTU의 폐수를 고분자응집제 주입 없이 10 NTU 이하로 처리할 수 있었으며, 유체유동해석 모델을 활용한 설계인자 도출의 가능성을 확인하였다.

• 한국자동차공학회논문집
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• 제19권1호
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• pp.101-108
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• 2011

Understanding the exhaust gas recirculation (EGR) cooler fouling in diesel engine is important factor in the durability characteristic of a EGR system. We develope a test rig and PM feeder using carbon black to examine the effect of fouling on EGR cooler devices those were consisted of flat and shell & tube type. The EGR cooler fouling process is a complex interaction involving heat exchanger shape, boundary condition, constitutes, chemistry and operating mode. As the soot deposited to EGR cooler, these formed a thin deposit layer that was less heat exchange than the fresh status of tube enclosing the exhaust gas, resulting in lower heat exchange effectiveness in both type coolers. But these deposits caused different results in pressure drop, it is increased in flat type, but decreased in Shell & tube type of EGR cooler. A cause was estimated from a change of the flow structure and a decrease of contact area as the EGR cooler fouling.

• 한국의류산업학회지
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• 제11권3호
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• pp.427-436
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• 2009

The purpose of this study is to analyze whether environmental and organizational characteristics have an effect on continuous acceptance intention and performance of the internet business in fashion companies. A survey was conducted from January 15 to February 15 in 2009, among members of fashion companies carrying out internet business. The data was collected with 288 subjects, the statistical analysis methods were frequency analysis, factor analysis, reliability analysis and multiple regression analysis. The results of this study were as follows; First, environment characteristics(internal pressure, external pressure) and organizational characteristics(chief executive officer, capacity of the organization and future directivity) of the fashion companies had an effect on continuous acceptance intention of the internet business. Second, environment characteristics and organizational characteristics of the fashion companies had an partially effect on performance of the internet business. Third, elevation of the business, customer relationship improvement and raise the market reactivity in performance factors of the fashion companies had an effect on continuous acceptance intention of the internet business.

• Environmental Engineering Research
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• 제23권4호
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• pp.397-405
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• 2018

As regulations governing the control of volatile organic compounds (VOCs) have become increasingly stringent in China, regenerative thermal oxidizers (RTOs) have been more frequently applied in medium- and high-concentration VOCs treatments. However, due to the lack of existing RTO-related research, experience remains a dominant factor for industrial application. This paper thus aimed to establish a model for industrial RTOs, using a transient simulation method and thermal equilibrium model to simulate the internal velocities and temperature distributions of an RTO across multiple cycles. A comparison showed an error of less than 5% between most correlating simulated and experimental measurement points, verifying that the simulation method was accurate. After verification, the velocity and temperature fields inside the RTO were simulated to study the uniformity of temperature and velocity within the packed beds: both fields displayed high uniformity after gas flowed through the honeycomb regenerator. The effects of air volume, VOCs concentrations, and valve switching times on the oxidation chamber temperature, RTO outlet temperature, and thermal efficiency (as well as their averages) were studied. The VOCs removal rate in this study was constantly above 98%, and the average thermal efficiency reached 90%.

• Mycobiology
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• 제47권1호
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• pp.50-58
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• 2019

Agarum clathratum, a brown macroalgae species, has recently become a serious environmental problem on the coasts of Korea. In an effort to solve this problem, fungal diversity associated with decaying A. clathratum was investigated and related ${\beta}$-glucosidase and endoglucanase activities were described. A total of 233 fungal strains were isolated from A. clathratum at 15 sites and identified 89 species based on morphology and a multigene analysis using the internal transcribed spacer region (ITS) and protein-coding genes including actin (act), ${\beta}$-tubulin (benA), calmodulin (CaM), and translation elongation factor (tef1). Acremonium, Corollospora, and Penicillium were the dominant genera, and Acremonium fuci and Corollospora gracilis were the dominant species. Fifty-one species exhibited cellulase activity, with A. fuci, Alfaria terrestris, Hypoxylon perforatum, P. madriti, and Pleosporales sp. Five showing the highest enzyme activities. Further enzyme quantification confirmed that these species had higher cellulase activity than P. crysogenum, a fungal species described in previous studies. This study lays the groundwork for bioremediation using fungi to remove decaying seaweed from populated areas and provides important background for potential industrial applications of environmentally friendly processes.

• International Journal of Advanced Culture Technology
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• 제9권1호
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• pp.7-15
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• 2021

The open space of the healing facility should contribute to the psychological and social healing of the users, provide a social environment for rest, and provide a design factor to support the walking path to move to the destination-connected space. In this paper, I examined the relationship between the environmental elements, spatial devices, and the characteristics of the design factors in the open space for healing facilities. As a research method, based on the analysis of previous studies, a healing facility in modern society was defined, and the relationship between the social support and physical environment factors of the healing facility where open space was considered. Through the consideration of cases, the characteristics of the physical space environment, and the design factors of the open space in the healing facility were categorized. As a result of research, open space in the healing facility is a space to promote a social exchange of users, as a physical form for accommodating psychological and social healing functions, it is necessary to construct the connection of the external space with the internal space.