• Title/Summary/Keyword: 매개 모델

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Inhibitory Effects of Anthocyanins Isolated from Black Soybean (Glycine max L.) Seed Coat on Degranulation and Cytokine Generation in RBL-2H3 Cells (검정콩 껍질 유래 안토시아닌의 RBL-2H3 세포에서 탈과립화와 사이토카인 생성 저해 효과)

  • Chung, Mi-Ja;Ha, Tae-Joung;Choi, Ha-Na;Lee, Ji-Sun;Park, Yong-Il
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.12
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    • pp.1662-1667
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    • 2011
  • Anthocyanins belong to a group of flavonoid compounds and are well known for their various health beneficial effects, which include antioxidative activities. Among them, the major anthocyanins isolated from seed coat of black soybean (Glycine max L.) were previously characterized as glycosides containing glucopyranose. Asthma is an allergic disease that is strongly associated with various immune cells, including basophils and mast cells. Eosinophils, basophils, and mast cells play important roles in allergic asthma through the release of inflammatory mediators such as asthma-specific T-helper 2 (Th2) cytokines and subsequent amplification of asthma symptoms via degranulation. Rat basophilic leukemia RBL-2H3 cells are the most common in vitro models for evaluating allergic reactions. In this study, we examined the effects of anthocyanin from seed coat of black soybean on antigen-stimulated degranulation and Th2 cytokine production in RBL-2H3 cells. Cell degranulation was evaluated by measuring the release of ${\beta}$-hexosaminidase. ${\beta}$-Hexosaminidase release and Th2 cytokine production in RBL-2H3 cells was much higher upon stimulation with IgE-antigen complex than those in untreated control cells. Anthocyanins significantly suppressed IgE-antigen complex-induced degranulation of RBL-2H3 cells and inhibited IgE-antigen complex-mediated interleukin (IL)-4, IL-13, and tumor necrosis factor ${\alpha}$ (TNF-${\alpha}$) production in RBL-2H3 cells. These findings suggest that anthocyanins from seed coat of black soybean effectively inhibit allergic reactions and may have beneficial effects against allergic asthma.

Study of Rainfall-Runoff Variation by Grid Size and Critical Area (격자크기와 임계면적에 따른 홍수유출특성 변화)

  • Ahn, Seung-Seop;Lee, Jeung-Seok;Jung, Do-Joon;Han, Ho-Chul
    • Journal of Environmental Science International
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    • v.16 no.4
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    • pp.523-532
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    • 2007
  • This study utilized the 1/25,000 topographic map of the upper area from the Geum-ho watermark located at the middle of Geum-ho river from the National Geographic Information Institute. For the analysis, first, the influence of the size of critical area to the hydro topographic factors was examined changing grid size to $10m{\times}10m,\;30m{\times}30m\;and\;50m{\times}50m$, and the critical area for the formation of a river to $0.01km^2{\sim}0.50km^2$. It is known from the examination result of watershed morphology according to the grid size that the smaller grid size, the better resolution and accuracy. And it is found, from the analysis result of the degree of the river according to the minimum critical area for each grid size, that the grid size does not affect on the degree of the river, and the number of rivers with 2nd and higher degree does not show remarkable difference while there is big difference in the number of 1st degree rivers. From the results above, it is thought that the critical area of $0.15km^2{\sim}0.20km^2$ is appropriate for formation of a river being irrelevant to the grid size in extraction of hydro topographic parameters that are used in the runoff analysis model using topographic maps. Therefore, the GIUH model applied analysis results by use of the river level difference law proposed in this study for the explanation on the outflow response-changing characters according to the decision of a critical value of a minimum level difference river, showed that, since an ogival occurrence time and an ogival flow volume are very significant in a flood occurrence in case of not undertow facilities, the researcher could obtain a good result for the forecast of river outflow when considering a convenient application of the model and an easy acquisition of data, so it's judged that this model is proper as an algorism for the decision of a critical value of a river basin.

Sampling Plan for Bemisia tabaci Adults by Using Yellow-color Sticky Traps in Tomato Greenhouses (시설토마토에서 황색트랩을 이용한 담배가루이 표본조사법)

  • Song, Jeong Heub;Lee, Kwang Ju;Yang, Young Taek;Lee, Shin Chan
    • Korean journal of applied entomology
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    • v.53 no.4
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    • pp.375-380
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    • 2014
  • The sweetpotato whitefly (SPW), Bemisia tabaci Gennadius, is a major pest in tomato greenhouses on Jeju Island because they transmit viral diseases. To develop practical sampling methods for adult SPWs, yellow-color sticky traps were used in commercial tomato greenhouses throughout the western part of Jeju Island in 2011 and 2012. On the basis of the size and growing conditions in the tomato greenhouses, 20 to 30 traps were installed in each greenhouse for developing a sampling plan. Adult SPWs were more attracted to horizontal traps placed 60 cm above the ground than to vertical trap placed 10 cm above the plant canopy. The spatial patterns of the adult SPWs were evaluated using Taylor's power law (TPL) and Iwao's patchiness regression (IPR). The results showed that adult SPWs were aggregated in each surveyed greenhouse. In this study, TPL showed better performance because of the coefficient of determination ($r^2$). On the basis of the fixed-precision level sampling plan using TPL parameters, more traps were required for higher precision in lower SPW densities per trap. A sequential sampling stop line was constructed using TPL parameters. If the treatment threshold was greater than 10 maximum adult SPWs on a trap, the required traps numbered 15 at a fixed-precision level of 0.25. In estimating the mean density per trap, the proportion of traps with two or more adult SPWs was more efficient than whole counting: ${\ln}(m)=1.19+0.90{\ln}(-{\ln}(1-p_T))$. The results of this study could be used to prevent the dissemination of SPW as a viral disease vector by using accurate control decision in SPW management programs.

Traffic Forecasting Model Selection of Artificial Neural Network Using Akaike's Information Criterion (AIC(AKaike's Information Criterion)을 이용한 교통량 예측 모형)

  • Kang, Weon-Eui;Baik, Nam-Cheol;Yoon, Hye-Kyung
    • Journal of Korean Society of Transportation
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    • v.22 no.7 s.78
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    • pp.155-159
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    • 2004
  • Recently, there are many trials about Artificial neural networks : ANNs structure and studying method of researches for forecasting traffic volume. ANNs have a powerful capabilities of recognizing pattern with a flexible non-linear model. However, ANNs have some overfitting problems in dealing with a lot of parameters because of its non-linear problems. This research deals with the application of a variety of model selection criterion for cancellation of the overfitting problems. Especially, this aims at analyzing which the selecting model cancels the overfitting problems and guarantees the transferability from time measure. Results in this study are as follow. First, the model which is selecting in sample does not guarantees the best capabilities of out-of-sample. So to speak, the best model in sample is no relationship with the capabilities of out-of-sample like many existing researches. Second, in stability of model selecting criterion, AIC3, AICC, BIC are available but AIC4 has a large variation comparing with the best model. In time-series analysis and forecasting, we need more quantitable data analysis and another time-series analysis because uncertainty of a model can have an effect on correlation between in-sample and out-of-sample.

The Study on the Influence of Selection Characteristics of Franchise System, business possibility, Communication, Moral Hazard on Franchisee's Perceived Risk, and Recontracting Intention in the Food Service Franchise Industry (외식 프랜차이저의 사업성, 커뮤니케이션, 모럴해저드가 프랜차이지의 위험지각과 재계약의도에 미치는 영향)

  • Yu, Jong-Pil;Lee, In-Ho
    • Journal of Distribution Research
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    • v.16 no.1
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    • pp.1-27
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    • 2011
  • I. Introduction: This study is to examine the structural relationships among exogenous variable (preliminary and post-support, franchisee's perceived business possibility, communication, moral hazard), the mediated variables(satisfaction, perceived risk, trust) and dependent variable(recontracting intention) in the food service franchise industry context. More specifically, this study has considered some realistic characteristics factors influencing satisfaction, perceived risk and trust between franchisors and franchisees and their further recontracting intention from the perspective of a practical approach. In this study, 437 data has been collected and used for the SPSS and AMOS analysis. The data were analyzed with structural equation modeling. Since the result of the overall model analysis demonstrated a good fit, we could further analyze our data. II. Research Model: This study is to examine the structural relationships among preliminary and post-support by franchisor, franchisee's perceived business possibility, and communication, moral hazard, has on effect on franchisee's satisfaction, perceived risk, trust and recontracting intention in the food service franchise industry context. Hypotheses are as following (Stern & EL-Ansary 1988; Oliver, 1997;Kee & Knox, 1970; Moorman, Deshpande & Zaltman, 1993; Perron, 1998; Zaheer, McEvily, Perrone, 1998). III. Result and Implication: We examined franchisee who have food service stores for samples of this study. The data were analyzed with structural equation modeling using path analysis. The result of the overall model analysis appeared as following: ${\chi}^2$ = 61.578 (d.f.=9, p<0.01), CFI =.990, GFI =.973, AGFI =.863, RMR =.019, RMSEA= .116, NFI = .988, TLI = .959. The findings can be summarized as follows: First, preliminary and post support of franchisor, perceived business possibility and communication positively influence to franchisee's satisfaction. Second, moral hazard of franchisor has negatively influence to franchisee's satisfaction and positively influence to perceived risk. Third, franchisee's satisfaction and trust has positively influence to recontracting intention. Fourth, franchisee's perceived risk has negatively influence to trust and recontracting intention. We can concluded that franchisor's preliminary and post support of franchisor, perceived business possibility and communication may be considered as the important factors influence to franchisee's satisfaction. Moral hazard has become a focused issue in franchise industry. Finally, the managerial implication has been stated as followings: First, in the process of building a systematic industry support franchise system and developing a creative business model, franchisee's stable profitability should be considered as the first important factor. The franchisee's trust to franchise may become a dominant factor that influence the business expansion of franchisor. Second, franchisor should communication with their franchisees and deal with the realistic difficulties faced by them with an effort. Third, the franchisor should achieve a synergy effect by utilizing the win-win strategy. The moral hazard strategy that achieving the profit through franchisee's damage will not be inadvisable to franchisor. Then the long-term oriented development and profitability can be maintained. To do so, the franchise industry may break away from the traditional business structure to improve management transparency and competitiveness on investment and organizational changing management. The conflict between franchisor and franchisee also can be reduced and big success can be achieved in the franchise industry.

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Seroprevalence and Risk Factors for Severe Fever with Thrombocytopenia Syndrome among the Korea National Park Service Workers (국립공원 종사자의 중증열성혈소판감소증후군 혈청유병률 및 위험요인)

  • Kim, Dong-Hwi;Kim, Kye-Hyung;Yi, Jongyoun;Ko, Mee Kyung;Park, Sung-Jun;Yoo, Seok-Ju;Lee, Kwan;Park, Ji-Hyuk
    • Journal of agricultural medicine and community health
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    • v.46 no.3
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    • pp.162-170
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    • 2021
  • Objectives: This study was carried out to understand the seroprevalence and risk factors for severe fever with thrombocytopenia syndrome (SFTS) among the Korea National Park Service (KNPS) workers. Methods: We used the stored serum samples (763) and survey results collected from the previous investigation on scrub typhus and Lyme disease among the KNPS workers during 2016-2017. The serum samples were analyzed by double-antigen sandwich enzyme-linked immunosorbent assay, which was used to test the total antibody including IgG and IgM. Results: The SFTS seroprevalence among the KNPS worrkers was 1.4%. In multivariate logistic analysis, the national park exploration programs (odds ratio, 3.48; 95% confidence interval, 1.01-12.01) was significantly associated with the seroprevalence of SFTS. Conclusion: This study was the first serological study of SFTS among forestry workers in South Korea. Although the KNPS workers are at a high-risk group of SFTS, the prevention activities related to the working environment and habit was insufficient. Thus, systematic prevention education and training for the KNPS workers need to be strengthened.

A Study on the Entrepreneurial Orientation and the Performance of Startups: The Mediating Effects of Technological Orientation and Social Capital (스타트업의 기업가지향성과 성과에 관한 연구: 기술지향성과 사회적 자본의 매개효과)

  • Lee, Eun A;Seo, Joung Hae;Shim, Yun Soo
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.14 no.2
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    • pp.47-59
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    • 2019
  • Various studies have been carried out on the subject of entrepreneurship, which is required to create new businesses and organizations during the early process of startups based on innovative technologies and ideas. At the same time, the concept of organizational entrepreneurial orientation, which explains how to manage enterprises in the process of pioneering new products and markets, is drawing more and more attention for the purpose of continuously creating and maintaining a competitive edge of startups. This study focused on the relationship between entrepreneurial orientation and startup performance and the role of technological orientation and social capital. An empirical research was conducted on 144 different startup companies residing in startup supporting institutions. To evaluate the suitability of the research model, a PLS-based structural equation model was used. The research results are as follows: First, the entrepreneurial orientation of startups was found to have a positive effect on startup performance. Second, it was shown that entrepreneurial orientation had a positive effect on all three dimensions of social capital and technological orientation. Third, it has been shown that technological orientation and the cognitive dimension of social capital mediates the relationship between entrepreneurial orientation and startup performance. Through this, it was confirmed that entrepreneurial orientation directly affects startup performance, and it even influences the growth of startups by increasing technological superiority and social capital which is inherent in the network. Also, the research identified the need for additional research on the relationship between the strengthening of technological orientation and strategical orientation in startups. This study is expected to expand the discussion about social capital in the field of startup related research by affirming the role and importance of the cognitive system embedded in the network as well as the connectivity of networks, which has been already emphasized in previous startup related studies. Finally, the results of this study were reflected to present new practical implications.

The Effect of Technology Startups' Value Chain Internal and External Network Activities on Competitive Advantage Through Dynamic Capabilities (기술창업기업의 가치사슬내부 및 외부 네트워크 활동이 동적역량을 매개로 경쟁우위에 미치는 영향)

  • Hong, Inki;Kim, Hyung-Jun
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.17 no.5
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    • pp.17-30
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    • 2022
  • It has been verified in several studies that dynamic capabilities has a very important effect on the competitive advantage of technology startups. And the network has an important influence on this dynamic capability. This is even more important for start-ups that lack the resources and knowledge. Networks that directly and significantly affect dynamic capabilities have been studied mainly the value chain internal. However, network activities of start-ups are conducted not only with the value chain internal networks but also with the value chain external networks. Therefore, it is necessary to study the effect of the value chain internal and external network activity of start-ups on the dynamic capabilities, but prior studies are lacked. In this study, We make a model that encompass the value chain internal and external network for technology startups, and a study was conducted to demonstrate the effect on dynamic capabilities and competitive advantage. As a result of the study, value chain internal network activity directly and significantly affected dynamic capabilities, and value chain external network activity did not directly significantly affect dynamic capacity. And dynamic capabilities had a significant effect on competitive advantage. As confirmed through additional research, value chain external network activity affects value chain internal network activity, and through this, dynamic capabilities are strengthened, and positively affect competitive advantage.. The intensity of value chain external network activity was not significant to dynamic capabilities and the diversity of value chain external network activity had a significant effect on the competitive advantage by double mediating the value chain internal network activity and dynamic capability. Through this study, it is confirmed that the value chain internal networks is important in order for startups to strengthen their dynamic capabilities and increase their competitive advantage, and that both strong and diversified the value chain internal networks positively affects competitive advantage by enhancing dynamic capabilities.

A Study on Moment Gradient Factor for Inelastic Lateral-Torsional Buckling Strength of Stepped I-Beam Subjected to Linear Moment Gradient (선형 모멘트 하중을 받는 계단식 단면변화 I형보의 비탄성 횡-비틀림 좌굴강도산정을 위한 모멘트 구배계수 연구)

  • Park, Jong-Sup;Son, Ji-Min
    • Journal of the Korean Society of Hazard Mitigation
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    • v.8 no.6
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    • pp.53-60
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    • 2008
  • The cross-sections of continuous multi-span beams sometimes suddenly increase, or become stepped, at the interior supports of continuous beams to resist high negative moments. The three-dimensional finite-element program ABAQUS (2007) was used to analytically investigate the inelastic lateral-torsional buckling behavior of stepped beams subjected to linear moment gradient and resulted in the development of design equations. The ratios of the flange thickness, flange width, and stepped length of beam are considered for the analytical parameters. Two groups of 27 cases and 36 cases, respectively, were analyzed for doubly and singly stepped beams in the inelastic buckling range. The combined effects of residual stresses and geometrical imperfection on inelastic lateral-torsional buckling of beams are considered. First, the distributions of residual stress of the cross-section is same as shown in Pi and Trahair (1995), and the initial geometric imperfection of the beam is set by central displacement equal to 0.1% of the unbraced length of beam. The new proposed equations definitely improve current design methods for the inelastic lateral-torsional buckling problem and increase efficiency in building and bridge design.

The effects of the degree of education related to information systems on online transaction intention and security concerns - Comparative analysis of the use of the Internet and smartphone (정보시스템 관련 교육의 정도가 보안 우려 및 온라인 거래 의도에 미치는 영향 - 인터넷 이용과 스마트 폰 이용의 비교 분석)

  • Jung, Seung-Min
    • Journal of the Korea Society of Computer and Information
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    • v.17 no.8
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    • pp.145-161
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    • 2012
  • This study aims to explore how the degree of education related to information systems and the Internet literacy affect perceived security risk and how these three variables affect online transaction intention based on the Technology Acceptance Model (TAM). Since using smartphone to purchase necessary products is increasing, the study provided two different cases of using the existing Internet and smartphone to buy products. As a result of an empirical test, the degree of information system education, internet literacy, and perceived security risk had significant effects on online transaction intention mediating perceived usefulness and perceived ease of use. Unlike the expectation, the more people have education related to information systems, the more they have knowledge about hacking or cases of privacy infringement, leading to even more concerns about security, thereby believing the Internet transactions require much effort. The more the education about information system, the more we have concerns about security; therefore, perceived security risk have a positive(+) effect on perceived usefulness not a negative(-) effect. Lastly, while the degree of education related to information systems has relations with the recognition of the usefulness of the Internet transaction, the study showed that there are no relations of recognizing the usefulness and the ease of use of smartphone.