• Macromolecular Research
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• 제13권3호
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• pp.257-264
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• 2005

Polyurethanes containing z-Iysine segments in the main chain (PULL) were synthesized from 4,4'-diphe-nylmethyl diisocyanate, poly(tetramethylene glycol), and z-Iysine oligomer as a chain extender. The PULL film was treated first with a $10\%$ HBr-acetic acid solution and subsequently with a saturated sodium bicarbonate aqueous solution to produce a primary amine group on the surface (PULL-N). Lactobionic acid (LA)-immobilized PULL (PULL-L) was prepared by the coupling reaction of the PULL surface amine groups and the LA carboxylic acid groups. The surface-modified PULLs were then characterized by attenuated total reflection-Fourier transform infra-red spectroscopy, electron spectroscopy for chemical analysis, atomic force microscopy, and contact angle goniometry. In the hepatocytes adhesion experiment, the cells poorly adhered to the PULL surface, although they adhered moderately well to the PULL-N surface. On the other hand, the cells adhered well to the PULL-L surface, suggesting the good affinity of the surface $\beta$-galactose moieties for hepatocytes. When hepatocytes were cultured in the presence of epidermal growth factor for 48 h, the cells rapidly aggregated on the PULL-L surface, whereas they aggregated only slowly on the other surfaces. The PULL prepared in this study has the potential to be used as a coating material for the enhancement of hepatocyte adhesion.

• Journal of Nutrition and Health
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• 제50권2호
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• pp.192-200
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• 2017

최근 음식상품 특화 필요 지역인 전주 한옥마을의 방문객이 증가함에 따라 전주 향토 음식의 상품 개발이 지속적으로 추진되고 있다. 이에 본 연구는 전주 한옥마을 내 방문객의 음식 구매 현황과 방문 동기, 만족도 간의 영향관계를 분석하여 전주 한옥마을 내 건강한 음식문화 형성에 기여하고자 하였다. 선행연구를 바탕으로 개발한 설문조사지를 이용하여 전주시 방문 경험이 있는 한국 성인 590명을 대상으로 설문조사를 수행하였으며 그 중 총 580부가 분석에 이용되었다. 그 결과, 전주 한옥마을 방문 경험이 있는 연구대상자 (n = 508)의 전주 한옥마을 내 음식 구매경험은 '있다 (96.4%)'가 '없다 (3.6%)'보다 높게 나타났으며, 구매 음식 유형은 '전통 한식 (26.5%)', '외국 음식 (25.8%)', '한국 식재료를 포함한 외국 음식 (16.8%)' 순으로 나타나 전주 한옥마을 내에서 다양한 음식 상품을 구매한 것으로 나타났다. 음식 구매 만족도 (3.35점)는 보통 이상으로 나타났으며 만족 이유는 '음식이 맛있어서 (59.6%)', '다양한 음식을 맛볼 수 있어서 (29.8%)' 순으로, 불만족 이유는 '음식의 가격이 비싸서 (48.1%)', '음식이 맛없어서 (19.5%)' 순으로 높은 응답률을 보였다. 방문객의 방문 동기를 추진 요인과 유인 요인으로 구분하여 분석한 결과, 추진 요인으로 '지역음식추구', '경험추구', '휴식추구', '친목추구' 요인이 도출되었으며 유인 요인으로 '전통문화', '시설편리', '체험활동', '음식경험' 요인이 도출되었다. 추진-유인 요인 간의 상호연관성 분석 결과, 유의한 상관관계가 있는 것으로 나타났으며 그 중 유인 요인인 '음식경험' 요인이 추진 요인인 '지역음식추구', '휴식추구', '친목추구' 요인에 가장 높은 상관관계가 있는 것으로 나타났다. 추진-유인 요인과 방문 만족도간의 영향 관계 분석 결과, 모든 추진 요인이 만족도에 영향을 미치는 것으로 나타났으며 유인 요인은 '음식경험', '전통문화' 요인만이 만족도에 영향을 미치는 것으로 나타났다. 이에 본 연구에서는 전주 한옥마을 방문객의 음식 구매 만족도, 만족-불만족 이유를 분석하여 전주 한옥마을 내 음식문화 형성의 방향성을 제시하였으며, 전주 한옥마을 내 음식 요인이 방문객의 내재적 방문동기 (추진 요인)와 만족도에 영향을 주는 요인임을 밝혀내었다. 이를 통해 전주 한옥마을의 음식 요인 관련 연구의 중요성을 시사하였으며 전주 한옥마을 음식 문화 포지셔닝 전략 수립에 유용한 기초자료를 제공하여 전주 한옥마을의 건강한 음식문화 형성에 기여하고자 하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.489-492
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• 2000

A novel low-cost simple and unity-power-factor electronic ballast is presented. The proposed electronic ballast employs a bypassing capacitor and load networks composed of ballast capacitors and small charge pump capacitors as power factor correction circuit combined with the secondary winding of the transformer in the self-excited current-fed push-pull resonant inverter(CF-PPRI) resulting in cost-effectiveness and higher efficiency. By analyzing the principles of power factor correction mathematically optimum design guidelines are presented. Since the lamps are used in power factor correction stage the input power is automatically adjusted according to the number of the lamps.

• 한국식생활문화학회지
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• 제24권4호
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• pp.401-412
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• 2009

The aims of study were to provide basic data for the internationalization of Contract Foodservice Management Companies (CFMC) and to gain a better understanding of internal push-and-pull factors through in-depth interviews. The interviewees were managers of four large CFMCs and one small-to-medium CFMC. The non-structured interview format employed an interview guide of open-ended questions. All interviews were digitally recorded and notes were taken simultaneously by an interview assistant. The narrative data analysis involved transcription, coding, classification by categories, and content analysis. Eighty-eight codes were generated from the interview analyses, and the subordinate variables uncovered included seven push factors, eight pull factors, one interactive factor, and 10 internal dynamics. These factors will be useful in further studies of the internal operations of specific CFMCs, and more generally, the practical condition of the industry.

• Geomechanics and Engineering
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• 제17권2호
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• pp.165-173
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• 2019

Plate anchors are generally used for structures like transmission towers, mooring systems etc. where the uplift and lateral forces are expected to be predominant. The capacity of anchor plate can be increased by the use of geosynthetics without altering the size of plates. Numerical simulations have been carried out on three different sizes of square anchor plates. A single layer geosynthetic has been used as reinforcement in the analysis and placed at three different positions from the plate. The effects of various parameters like embedment ratio, position of reinforcement, width of reinforcement, frequency and loading amplitude on the pull out capacity have been presented in this study. The load-displacement behaviour of anchors for various embedment ratios with and without reinforcement has been also observed. The pull out load, corresponding to a displacement equal to each of the considered maximum amplitudes of a given frequency, has been expressed in terms of a dimensionless breakout factor. The pull out load for all anchors has been found to increase by more than 100% with embedment ratio varying from 1 to 6. Finally a semi empirical formulation for breakout factor for square anchors in reinforced soil has also been proposed by carrying out regression analysis on the data obtained from numerical simulations.

• Journal of Korea Trade
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• 제26권6호
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• pp.20-40
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• 2022

Purpose - In recent times, the international trade environment has been changing rapidly, centering on the online market. In the post-COVID-19 era, small and medium-sized trading companies are facing the problem of not being properly provided with overseas market research, market trend analysis, and trade-related information. Cloud-based digital trade is being sought as an alternative to solve these problems; however, there is a lack of research on the intention to switch to digital trade among small and medium-sized trading companies. Therefore, this study empirically analyzes the intention to switch to digital trade based on the migration theory, and through this, attempts to identify each factor that affects the intention to switch to digital trade. Design/methodology - In this study, in order to identify factors influencing intention to switch to digital trade and innovation resistance of small and medium-sized trading companies, through previous research on migration theory and the PPM (Push, Pull, Mooring) model, each variable was selected for the purpose of the study. Based on this, a research model was established for the factors affecting switching to digital trade of small and medium-sized trading companies and empirically analyzed. In addition, considering the differences in the innovation propensity and maturity of information infrastructure of trading companies as the recipients of innovation, this study analyzes the moderating effect of the mooring effect and seeks ways to establish specific strategies according to the degree. Findings - As a result of empirical analysis, the pull effect was found to have the greatest influence on intention to switch to digital trade. However, the pull factor was found to have an effect on user resistance, and it was confirmed that it was a factor simultaneously inducing positive and negative consumption behaviors among users. In addition, it was found that the higher the company's innovation propensity, the higher the pull effect's influence on the intention to switch, and analysis showed that the push effect had no influence. In addition, companies with high information infrastructure maturity were expected to have a relatively high level of intention to switch compared to companies with low information infrastructure maturity, and the difference between the two groups was found not to be statistically significant. Originality/value - This study is a timely study in that it demonstrated the effect on the switching to cloud-based digital trade for small and medium-sized trading companies and that the cloud system related to digital trade is in full swing. There are academic implications in that it revealed that the pull effect is an important factor in the intention to switch to cloud service. Practical implications were presented in that small and medium-sized trading companies suggested ways to increase the value of the cloud system for switching to digital trade and a way to increase the switching ratio by minimizing the mooring effect. In addition, the study argues that active institutional support from the government is needed to activate cloud service.

• 한국산업보건학회지
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• 제15권1호
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• pp.36-44
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• 2005

A push pull hood system is frequently applied to control contaminants evaporated from an open surface tank in recent years. Efficiency of push pull hood system is affected by various parameters, such as cross draft, vessel shapes, size of tanks surface, liquid temperature, and so on. Among these, velocity of cross draft might be one of the most influencing factor for determining the ventilation efficiency. To take account of the effect of cross draft velocities over 0.38m/s, a flow adjustment of ${\pm}$20% should be considered into the push and +20% into the pull flow system Although there are many studies about the efficiency evaluation of push pull hood system based on CFDs(Computational Fluid Dynamics) and experiments, there have been no reports regarding the influence of velocities and direction of cross-draft on push-pull hood efficiency. This study was conducted to investigate the influence of cross draft direction and velocities on the capture efficiency of the push-pull ventilation system. Smoke visualization method was used along with mock-up of push-pull hood systems to verify the ventilation efficiency by experiments. When the cross-draft blew from the same origins of the push flows, the efficiency of the system was in it's high value, but it was decreased significantly when the cross-draft came from the opposite side of push flows Moreover, the efficiency of the system dramatically decreased when the cross-draft of open surface tank was faster than 0.4m/s.

• 한국운동역학회지
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• 제15권2호
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• pp.21-29
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• 2005

The Purpose of this study was to seek determinant factors through analysis of 65 snatch skill kinematic factors of Athletics participated in 2001 Asian weightlifting competetion. The conclusion were as follows ; 1. In order to enhance snatch skill, when barbell move on knee position, One should be flex knee joint to 105-110 degree, and In pull motion, One should be move powerful extension of knee and hip joint. 2. In last pull motion, One try to make more lock out motion than extra extention motion of hip joint 3. In order to enhance snatch skill, It is inportant that elevate barbell highly by last pull motion through powerful knee extention, poweful hip flextion and One should be make lock out motion fast in the same time. 4. In order to enhance snatch skill, anterior-posterior movement width of shoulder joint should be small. 5. In order to enhance snatch skill, Hip joint should be move vertically on start and lock out phase, but In pull phase, extension motion of hip joint shoulde be performed more largely and powerfully.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.342-347
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• 2004

Excavation nearby the existing structures is being performed vigorously to get the greatest use of land along with fast economic growth in the downtown area. The application of soil nailing system gradually increases because of an advantage of soil nailing system adjacently constructed in the existing structures. In this study, friction resistance by pull-out is considered as main resistance except resistance formed by flexural rigidity of nail observing that resistance of flexural rigidity is about $0{\sim}15\;%$ of whole safety factor according to degree of flexural rigidity in general soil nail wall and application of geosynthetic fiber soil nailing system is evaluated through laboratory tensile strength test and field pull-out test.

• 중소기업연구
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• 제42권3호
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• pp.221-243
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• 2020

본 연구는 재직중인 중장년층의 자립욕구와 창업성공가능성 및 고용안정성이 Push-창업의지를 매개로 Pull-창업의지에 미치는 영향을 알아보고자 한다. 경제 활성화와 고용확대를 위해 생계형 창업보다는 기회형 창업으로 질적 확대를 권장하고 있지만, 경험과 기술, 기회를 갖고 있는 중장년층이 기회형 창업보다는 생계형 창업으로 양적 창업 확대가 나타나는 것이 현상이다. 본 연구는 이런 현상에 대해 창업의지를 기존의 결과변수로 보기보다는 창업자 개인이 인식하는 창업성공가능성 및 고용안정성에 따라 창업의지를 자립욕구, Push-창업의지, Pull-창업의지로 구분하고 변수로 반영하여 그에 따른 영향을 연구하였다. 그 결과는 다음과 같다. 본 연구결과 첫째, 자립욕구는 Pull-창업의지와 Push-창업의지에 정(+)의 영향을 주는 것으로 나타났다. 둘째, 창업성공가능성은 Pull-창업의지에 정(+)의 영향을 Push-창업의지에는 유의적 영향을 주지 않는 것으로 나타났다. 셋째, 고용안정성은 Pull-창업의지에 정(+)의 영향을 Push-창업의지에는 유의적 영향을 주지 않는 것으로 나타났다. 넷째, 자립욕구는 Pull-창업의지에 정(+)의 영향을 Push-창업의지는 부(-)의 영향으로 매개효과가 있는 것으로 나타났다. 본 연구의 시사점으로는 실업에 밀려서 창업되는 생계형 창업보다는 자립욕구를 갖는 잠재창업자가 Push-창업의지의 상황이 개선되면 Pull-창업의지로 전개될 수 있음 인식하였다. 또한, 자립욕구를 갖는 재직자를 대상으로 창업교육과 창업프로그램의 활성화가 기회형 창업을 확대할 수 있는 방안으로 본다.