• Journal of Microbiology and Biotechnology
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• 제20권4호
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• pp.737-748
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• 2010

Glutaminase production in Zygosaccharomyces rouxii by solid-state fermentation (SSF) is detailed. Substrates screening showed best results with oatmeal (OM) and wheatbran (WB). Furthermore, a 1:1 combination of OM:WB gave 0.614 units/gds with artificial sea water as a moistening agent. Evaluation of additional carbon, nitrogen, amino acids, and minerals supplementation was done. A central composite design was employed to investigate the effects of four variables (viz., moisture content, glucose, corn steep liquor, and glutamine) on production. A 4-fold increase in enzyme production was obtained. Studies were undertaken to analyze the time-course model, the microbial growth, and nutrient utilization during SSF. A logistic equation ($R^2$=0.8973), describing the growth model of Z. rouxii, was obtained with maximum values of ${\mu}_m$ and $X_m$ at $0.326h^{-1}$ and 7.35% of dry matter weight loss, respectively. A goodfit model to describe utilization of total carbohydrate ($R^2$=0.9906) and nitrogen concentration ($R^2$=0.9869) with time was obtained. The model was used successfully to predict enzyme production ($R^2$=0.7950).

• 한국콘텐츠학회논문지
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• 제9권7호
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• pp.95-101
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• 2009

인지 라디오(Cognitive Radio: CR) 기술은 우선 사용자와 CR 사용자가 무선 자원을 공유하여 무선 자원의 효율을 증가시킬 수 있는 기술이다. 본 논문에서는 셀에서의 채널사용에 대한 부분정보만이 CR 사용자에게 알려져 있음을 가정하고 채널 할당 모델을 설계한다. 모델은 우선 사용자가 CR 사용자에 의하여 간섭받지 않도록 설계하였으며, CR사용자의 채널 재획득과정을 포함한다. 설계된 인지 라디오에서의 채널 할당 모델을 분석하기 위하여 이에 대한 페트리 네트 모델을 개발하였으며 성능분석을 수행 한다. 성능지표로는 우선사용자 채널 점유율 변화에 따른 CR 사용자의 호 분설률과 처리율을 계산한다.

• 무역상무연구
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• 제53권
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• pp.233-264
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• 2012

This study proposes and verifies an integrated model that reflects and helps to explain complexities and comprehensiveness of e-Trade in practice. The primary objective was to widen and deepen our understanding about the phenomena of paperless trading which will enable us to formulate an effective means to promote the adoption and utilization of e-Trade infrastructure. This investigation combined and extended the theories and models of TAM, TOE framework, and TTF in order to identify and hypothesize the causal relationships between factors of technology, organization and environment, and the usage level and performance of e-Trade. The previous research on e-Trade was reviewed and incorporated into the extended model. The integrated model was tested based on the survey data collected from a sample of 417 trading firms. Overall, the regression and path analysis demonstrated the usefulness of the proposed model as a conceptual framework for better understanding and explanation of e-Trade. The result of the analysis implies the relevancy of the factors of technology, organization and environment for facilitating usage of and increasing performance of e-Trade. However, rejection of a few hypothesized relationships implies the necessity of extensive promotion and education about the related laws and regulations, and education, supervision and incentives for e-Trade practitioners.

• 한국멀티미디어학회논문지
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• 제21권4호
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• pp.499-512
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• 2018

The application of analytical techniques for the rational determination of problems arising from management science and corporate management. In a way that is the opposite of the repair plan that can predict accurate results is increasing utilization of the complex-based analysis methodology. In this study, we examined the application of physical space and the methodological utilization of the pedestrian model analysis that applied the simulation to the Health Checkup Center. The conclusions are as follows. First, the spatial analysis and measurement for empirical research has confirmed that the efficiency assessment through the pedestrian model simulation can lead to an objective evaluation. Second, it seems to be able to reduce the queue through a change in the number of services of the low-pressure and the hearing laboratory, the recovery room with a high proportion of male disturbances and relatively long use time. The third, the spatial density analysis and the time required to reduce the density change in comparative analysis, and the spatial layout changes, the increase in the capacity of 80 people, approximately 16 minutes to shorten the process duration.

• 보건행정학회지
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• 제11권2호
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• pp.123-140
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• 2001

Hypotheses In health services research are becoming increasingly more complex and specific. As a result, health services research studies often include multiple independent, intervening, and dependent variables in a single hypothesis. Nevertheless, the statistical models adopted by health services researchers have failed to keep pace with the increasing complexity and specificity of hypotheses and research designs. This article introduces a statistical model well suited for complex and specific hypotheses tests in health services research studies. The covariance structure modeling(CSM) methodology is especially applied to regional relevance indices(RIs) to assess the impact of health resources and healthcare utilization. Data on secondary statistics and health insurance claims were collected by each catchment area. The model for RI was justified by direct and indirect effects of three latent variables measured by seven observed variables, using ten structural equations. The resulting structural model revealed significant direct effects of the structure of health resources but indirect effects of the quantity on RIs, and explained 82% of correlation matrix of measurement variables. Two variables, the number of beds and the portion of specialists among medical doctors, became to have significant effects on RIs by being analyzed using the CSM methodology, while they were insignificant in the regression model. Recommendations for the CSM methodology on health service research data are provided.

• 한국미생물·생명공학회지
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• 제47권2호
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• pp.195-200
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• 2019

The purpose of this study was to investigate the melanogenesis inhibiting activity of the ethanol extract from Polygonum amphibium L. Firstly, the n-hexane (Hx), chloroform ($CHCl_3$), ethyl acetate (EA), n-butanol (BuOH), and water (Water) fractions were isolated from the P. amphibium L. ethanol extract. The efficacy of melanogenesis was found to significantly decrease via the EA and BuOH fractions when compared to the control in B16F10 cells. EA particularly showed the lowest melanin content in B16F10 cells when compared to all the other extracts. Concentration-dependent inhibition of melanin synthesis was also observed in the EA fraction at concentrations below $50{\mu}g/ml$, which did not exhibit cytotoxicity in B16F10 cells. Notably, the expression of three key proteins (tyrosinase, tyrosinase-related protein-1 (TRP-1), and TRP-2), which are involved in melanogenesis, were significantly decreased via the EA fraction. EA also inhibited body pigmentation in vivo in a zebrafish model. Overall, we demonstrated melanogenesis suppression using the EA fraction from P. amphibium L., which could be a potential candidate for an antimelanogenesis agent.

• 한국조경학회지
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• 제38권5_2호
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• pp.151-162
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• 2010

This research aimed at measuring Park and Green Satisfaction (PGS) using subjective indicators of 'surface, line and spot' green evaluated by citizens. Also frequency of visits to park and green measured using objective indicators (number of visits) to find the relationship with PGS. A conceptual model of PGS was developed to relate evaluation to satisfaction and finally to utilization of open spaces. A sample of 500 questionnaire survey was employed for Uijeongbu City in Korea. A Structual Equation Modeling (AMOS) techniques was used to test the hypothesized relationship among factors (construct). As a result, first, PGS was explained by three latent factors of 'urban park' (${\gamma}=0.54$), 'linear facilities' (${\gamma}=0.25$), and 'surface green' (${\gamma}=0.15$) respectively. These three exogenous construct was found very useful classification system for open spaces of cities. Second, PGS (${\gamma}=0.34$) was found as a mediating variable to utilization of open spaces and also PGS was closely related to citizens Environmental Quality Satisfaction (EQS), such concept as, 'livability' and 'aesthetic quality'. The more satisfied with park and green the more people use the space. The PGS was an important QOL indicator together with the subjective indicator of 'livability'. Third, jogging and walking trails and bike ways along the river corridor was the most important green facilities contribute to the PGS and EQS. The near the distance (within 500m) the more number of visit to river corridor (green way). The river corridor promote accessibility to nature and other parks.

• 보건교육건강증진학회지
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• 제26권4호
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• pp.117-127
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• 2009

Objectives: The primary objective of the study is to analyze the utilization patterns of provincial patients discharged from hospitals located in Seoul area. Methods: For the analysis, the study employed the nationwide data on 'Survey of Injured Patients Discharged from Hospitals' conducted by KCDC (Korea Centers for Disease Control and Prevention). The statistical methodology used in the measurement model is a logistic regression model. Results: The study has three major findings. First, compared to other disease groups, the discharged on both 'neoplasm(cancer)' and 'congenital malformation, deformity and chromosomal abnormalities' disease groups are more likely to utilize hospitals in Seoul area. Second, as for 'neoplasm(cancer)' disease group, patients with 'bones and articular cartilage' areas are more likely to utilize hospitals in Seoul area. Finally, Hospitals with more than 1,000 beds was primary factor in selecting Seoul-based hospitals by the discharged in provincial areas. Conclusion: In sum, the study showed that patients in provincial areas are more likely to utilize hospitals located in Seoul area regardless of the severity of their cases. Local authority, therefore, is required to monitor local hospitals on regular basis, as well as support them to establish specialized medical centers by providing human and physical resources.

• 청소년시설환경
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• 제17권1호
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• pp.131-141
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• 2019

The purpose of this study is to derive and type utilization indexes by comparing public design indicators with preceding studies related to closed school facilities, and to derive preliminary classification systems through a correlation review between indicators. Pre-research was conducted in the scope of academic papers, academic journals, research reports, and special act for promoting the utilization of closed school assets. Public design indicators were set in the scope of domestic design guidelines, the Seoul city public design assessment system, the 'Good Building' designation system, and the UK Design Quality Index (DQI). and the design review of the British architects. First of all, the research method looked at laws, procedures and utilization of closed schools, and reviewed the preceding study and domestic and international public design indicators sequentially. Next, the association was reviewed through a comparison between the preceding study and the public design indicators, and a preliminary classification system for the use of closed schools was derived from this.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.802-807
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• 2005

For linear projects, it has long been known that resource utilization is important in improving work efficiency. However, most existing scheduling techniques cannot satisfy the need for solving such issues. This paper presents an optimization model for solving linear scheduling problems involving resource assignment tasks. The proposed model adopts constraint programming (CP) as the searching algorithm for model formulation, and the proposed model is designed to optimize project total cost. Additionally, the concept of outsourcing resources is introduced here to improve project performance.