• 동력기계공학회지
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• 제20권1호
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• pp.5-10
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• 2016

Swing check valve is opened when the flow direction is forward, when the flow is reversed, the valve is automatically closed by back pressure. In this study, the internal flow field analysis of the valve was conducted by Fluent. The working fluid used in the study, using liquefied methane $-165^{\circ}C$ (CH4) and velocity field, pressure field, pressure drop coefficient were simulated by varying separately the opening divergence into four intervals from 0 to 100%. The approximate research result are as follow : When the opening divergence is smaller, it appears high pressure on the upstream side, this value is relaxed when the opening divergence is large. Flow rate coefficient of the valve shows a larger value as the degree of opening becomes larger, confirming that the check valve used in the study is in the effective flow rate counting range.

• Asian-Australasian Journal of Animal Sciences
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• 제7권2호
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• pp.191-196
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• 1994

Two experiments were conducted to study the effect of using Egyptian mallow leaf meal (EMLM) on growth performance and feed utilization of common carp (Cyprinus carpio L.) in experiment 1. Four diets containing 0, 5, 15 and 25% EMLM were included at the expense of berseem leaf meal and fed to fingerlings of common carp for 98 days. The results showed that the average daily gain, feed intake and feed coefficient ratio (FCR) were improved (p<0.05) with increasing the level of EMLM in the diet. Fish fed 25% EMLM were similar to control fish (30% berseem leaf meal) in the productive value (PPV%). In experiment 2, five diets were prepared to contain: 1) 30% berseem leaf meal, 2) 25% untreated EMLM, 3) 25% cooked EMLM 4) 25% treated EMLM with 0.5% NaOH and 5) 25% treated EMLM with 1% NaOH. The results showed that diet containing EMLM gave the best growth performance and feed utilization. However, diet containing 1% NaOH treated EMLM superior to the other diets in PPV% and energy utilization. Diets containing 0.5% NaOH-treated EMLM or cooked EMLM decreased the protein utilization compared to those containing EMLM.

• 보건의료산업학회지
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• 제13권4호
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• pp.179-190
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• 2019

Objectives: This study aimed to investigate the mediating effects of health promotion behaviors on the correlation between self-perceived health and medical care utilization among older adults. Methods: This study used data from a. Data were analyzed with frequency analysis, descriptive statistics, Pearson's correlation coefficient, and hierarchical multiple regression. Mediation analysis was performed according to the Sobel test. Results: The self-perceived health and some health promotion behaviors in older adults had a statistically significant effect on medical care utilization. Only the nutritional management of health promotion behaviors had a mediating effect on the relation between the self-perceived health and medical care utilization of older adults. Conclusions: The nutritional management of older adults was confirmed as an important factor to health promotion and prevention. This study was meaningful in that it identified the political directions for establishing health care policy for the older adults.

• 대한안전경영과학회지
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• 제19권1호
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• pp.157-167
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• 2017

The two-way quality theory has been widely used as a method for classifying quality attributes for several decades. In particular, the Kano model that classifies attributes into not just conventional one-dimensional but must-be and attractive has gained popularity due to its applicability and ease of use. However, the wordings of the five alternatives in the Kano's questionnaire has been criticised for unclear meanings. This study proposes a new two-way model to classify attributes using 5-point Likert scale alternatives. For this, the current paper investigated a case of TV sets to examine how the proposed model works in comparison with the Kano model. The application results of the proposed model are different from the original one. The two-way model classifies quality attributes in more detail such as the "one-dimensional with an attractive tendency" attribute, which has a greater influence on satisfaction than dissatisfaction, the opposite "one-dimensional with a must-be tendency" attribute, and "highly one-dimensional" and "less one-dimensional" attributes. In this study, a potential satisfaction coefficient (PSC), a potential dissatisfaction coefficient (PDC), and an average potential coefficient (APC) to manage quality attributes are proposed and discussed for their utilization.

• 한국치위생학회지
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• 제11권5호
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• pp.791-799
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• 2011

Objectives : This study aimed at examining the aspects of utilization of the dental services in some regions and analyzing the related factors with a view to helping the old solve the dental problems and overcome the difficulties. Methods : This investigation was intended for 422 old people living in Jeon-ju city and Jang-su county from July 18, 2006 to August 25 by direct interviewing posing questions. The survey data sets were analyzed by chi-square, correlation, multiple regression and logistic regression. Results : 1. The average number of the existing teeth per an old person was 13.6 and the 28.8% of the old who didn't use denture called for dentures. 2. The annual coefficient of utilization in dental services for an old person was 52.3% and the annual average visits to dental clinics were 3.12 days while 38.6% of the old experienced illegal dental treatments. 3. The affecting factors on the dental utilization for treatment were as follows: family income, dental clinics available, the number of existing teeth, the days of dental trouble, the recognition of the prevention of the dental disease, the knowledge for the dental treatment and the oral health judged by himself. 4. The major variables influencing the utilization of dental services were spouse presence, form of family, income, having a regular dental care, denture presence and the experience of inconvenience in living. Conclusions : To conclude, the following suggestions could be made. First, It was necessary that enforcement practice of free dental prosthesis service and application to the national health insurance in old people's prosthetic therapy for government support because the economic factor was barrier to utilization of the dental services. Second, Dental clinic was required to the health center because availability of common dental services was big impact in utilization of the dental services.

• 상하수도학회지
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• 제12권1호
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• pp.62-69
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• 1998

To remove nitrogen from wastewater, ammonia nitrogen has to be oxidized to nitrate nitrogen before denitrification reaction which converts nitrate nitrogen to nitrogen gas. In order to understand nitrification, several mathematical models had been proposed and Monod type model has been accepted internationally. Since Monod type model consists of maximum substrate utilization rate, substrate concentration and half-saturation coefficient, these values have to be addressed before using Monod type model. Several experimental procedures to determine half-saturation coefficient have been developed, however, Infinite dilution method was known to be time saving procedure. In this study, the mathematical equations and experimantal procedures for Infinite dilution method are presented and this method is used to determine half-Saturation coefficient for nitrifying bacteria. As results, Infinite dilution method is proved that this coefficient can be determined within 8 hours and the values of half-saturation coefficient has a range of 0.728 and $0.455gNH_4{^+}-N/m^3$ and the average has $0.580gNH_4{^+}-N/m^3$ through 5 sets of experiments.

• 한국병원경영학회지
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• 제12권3호
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• pp.1-19
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• 2007

This study focused on finding the variation of medical service utilization and medical payments of the patients died by three, cancers, stomach, breast, and colon cancer. For this study, data of the one-year episodes of the health insurance subscribers died in 2004 were selected. The frequency of medical visits, the lengths of slays, the days of outpatient visits, the total period of medical services and the total medical payments were compared by the characteristics of the suppliers and utilizers. The data of the patients died by cerebrovascular diseases and cancer in 2004 were selected. To select the dead by cerebrovascular diseases and cancer in 2004, were matched the 2004 reimbursement data of all medical institutions to the data of funeral fee payment by the National Health Insurance Corporation from January 2004 to May 2005 for the death in 2004. The results of the analysis were as follow. The variation of medical service utilization of the dead by cancers were not small in Korea. The current study found that the variation of medical care utilization was influenced by the factors of suppliers, such as types and locations of medical institutions and the factors of users, such as sex and age. It was suspected that the reimbursement by fee-for-service contributed to the variation quite a lot, but we could not compare the variation between the different reimbursement systems in Korea. The results of the study suggested that tile factors of suppliers and utilizers should he reviewed to reduce the under use and over use expressed by variations of medical service utilization. The processes of care, effective communication and management system should be investigated for the equity of medical service utilization. Additionally, prospective payment could he recommended to reduce the high variation of medical service Use. To find the variation caused by under use and over use, further study need to control the severity of diseases, socio-economic status of the users and the system factors.

• Asia pacific journal of information systems
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• 제23권3호
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• pp.25-53
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• 2013

This study analyzes the effect of Computer Aided Innovation (CAI) to improve R&D Capabilities empirically. Survey was distributed by e-mail and Google Docs, targeting CTO of 235 SMEs. 142 surveys were returned back (rate of return 60.4%) from companies. Survey results from 119 companies (83.8%) which are effective samples except no-response, insincere response, estimated value, etc. were used for statistics analysis. Companies with less than 50billion KRW sales of entire researched companies occupy 76.5% in terms of sample traits. Companies with less than 300 employees occupy 83.2%. In terms of the type of company business Partners (called 'partners with big companies' hereunder) who work with big companies for business occupy 68.1%. SMEs based on their own business (called 'independent small companies') appear to occupy 31.9%. The present status of holding IT system according to traits of company business was classified into partners with big companies versus independent SMEs. The present status of ERP is 18.5% to 34.5%. QMS is 11.8% to 9.2%. And PLM (Product Life-cycle Management) is 6.7% to 2.5%. The holding of 3D CAD is 47.1% to 21%. IT system-holding and its application of independent SMEs seemed very vulnerable, compared with partner companies of big companies. This study is comprised of IT infra and IT Utilization as CAI capacity factors which are independent variables. factors of R&D capabilities which are independent variables are organization capability, process capability, HR capability, technology-accumulating capability, and internal/external collaboration capability. The highest average value of variables was 4.24 in organization capability 2. The lowest average value was 3.01 in IT infra which makes users access to data and information in other areas and use them with ease when required during new product development. It seems that the inferior environment of IT infra of general SMEs is reflected in CAI itself. In order to review the validity used to measure variables, Factors have been analyzed. 7 factors which have over 1.0 pure value of their dependent and independent variables were extracted. These factors appear to explain 71.167% in total of total variances. From the result of factor analysis about measurable variables in this study, reliability of each item was checked by Cronbach's Alpha coefficient. All measurable factors at least over 0.611 seemed to acquire reliability. Next, correlation has been done to explain certain phenomenon by correlation analysis between variables. As R&D capabilities factors which are arranged as dependent variables, organization capability, process capability, HR capability, technology-accumulating capability, and internal/external collaboration capability turned out that they acquire significant correlation at 99% reliability level in all variables of IT infra and IT Utilization which are independent variables. In addition, correlation coefficient between each factor is less than 0.8, which proves that the validity of this study judgement has been acquired. The pair with the highest coefficient had 0.628 for IT utilization and technology-accumulating capability. Regression model which can estimate independent variables was used in this study under the hypothesis that there is linear relation between independent variables and dependent variables so as to identify CAI capability's impact factors on R&D. The total explanations of IT infra among CAI capability for independent variables such as organization capability, process capability, human resources capability, technology-accumulating capability, and collaboration capability are 10.3%, 7%, 11.9%, 30.9%, and 10.5% respectively. IT Utilization exposes comprehensively low explanatory capability with 12.4%, 5.9%, 11.1%, 38.9%, and 13.4% for organization capability, process capability, human resources capability, technology-accumulating capability, and collaboration capability respectively. However, both factors of independent variables expose very high explanatory capability relatively for technology-accumulating capability among independent variable. Regression formula which is comprised of independent variables and dependent variables are all significant (P<0.005). The suitability of regression model seems high. When the results of test for dependent variables and independent variables are estimated, the hypothesis of 10 different factors appeared all significant in regression analysis model coefficient (P<0.01) which is estimated to affect in the hypothesis. As a result of liner regression analysis between two independent variables drawn by influence factor analysis for R&D capability and R&D capability. IT infra and IT Utilization which are CAI capability factors has positive correlation to organization capability, process capability, human resources capability, technology-accumulating capability, and collaboration capability with inside and outside which are dependent variables, R&D capability factors. It was identified as a significant factor which affects R&D capability. However, considering adjustable variables, a big gap is found, compared to entire company. First of all, in case of partner companies with big companies, in IT infra as CAI capability, organization capability, process capability, human resources capability, and technology capability out of R&D capacities seems to have positive correlation. However, collaboration capability appeared insignificance. IT utilization which is a CAI capability factor seemed to have positive relation to organization capability, process capability, human resources capability, and internal/external collaboration capability just as those of entire companies. Next, by analyzing independent types of SMEs as an adjustable variable, very different results were found from those of entire companies or partner companies with big companies. First of all, all factors in IT infra except technology-accumulating capability were rejected. IT utilization was rejected except technology-accumulating capability and collaboration capability. Comprehending the above adjustable variables, the following results were drawn in this study. First, in case of big companies or partner companies with big companies, IT infra and IT utilization affect improving R&D Capabilities positively. It was because most of big companies encourage innovation by using IT utilization and IT infra building over certain level to their partner companies. Second, in all companies, IT infra and IT utilization as CAI capability affect improving technology-accumulating capability positively at least as R&D capability factor. The most of factor explanation is low at around 10%. However, technology-accumulating capability is rather high around 25.6% to 38.4%. It was found that CAI capability contributes to technology-accumulating capability highly. Companies shouldn't consider IT infra and IT utilization as a simple product developing tool in R&D section. However, they have to consider to use them as a management innovating strategy tool which proceeds entire-company management innovation centered in new product development. Not only the improvement of technology-accumulating capability in department of R&D. Centered in new product development, it has to be used as original management innovative strategy which proceeds entire company management innovation. It suggests that it can be a method to improve technology-accumulating capability in R&D section and Dynamic capability to acquire sustainable competitive advantage.

• 대한방사선기술학회지:방사선기술과학
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• 제22권1호
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• pp.43-47
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• 1999

In order to obtain effective utilization of intensifying screens[$CaWO_4(W),\;Gd_2O_2S:Tb(Gd)$, BaFCl : Eu(Ba)] over the diagnostic radiology range, we calculated absorption coefficient (${\mu}$), absorption efficiency (${\eta}_{\alpha}$) and absorbed energy ratio(R) and analyzed effects of these properties on X-ray image, finally concluded as below. Regardless of presence of contrast media, absorption coefficient of Gd the highest and decreased with increase of thickness and kVp. Absorption efficiency related with absorbance of fluorescent materials showed the highest value for the Gd, and discontinuous points exhibited at around $80{\sim}90\;kVp$ and $90{\sim}100kVp$ for the Ba and the Gd, respectively. Furthermore, the absorbed energy ratio(R) correspond to contrast of reflection showed the largest value for the W in the absence of contrast media, and for the Gd in the case of the existence of it, and the ratio was decreased with increasing of incident energy. Owing to these properties, we assumed that it was more preferable to use rare earth type intensifying screen for the radiography using in the C.M.(I, Ba), while in the general radiography, $CaWO_4$ intensifying screen was applicable.

• Journal of Power Electronics
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• 제16권2호
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• pp.480-489
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• 2016

A novel hybrid carrier-based pulse width modulation (CBPWM) scheme that combines unipolar and dipolar modulations is proposed for single-phase three-level rectifiers, which are widely applied in railway traction drive systems. The proposed CBPWM method can satisfy the volt-second balancing principle in the complete modulation index region through overmodulation compensation. The modulation scheme features two modulation modes: unipolar and dipolar. The operation range limits of these modulation modes can be modified by changing the separation coefficient. In comparison with the traditional unipolar CBPWM, the proposed hybrid CBPWM scheme can provide advantageous features, such as lower high-order harmonic distortion of the line current and better utilization of switching frequency. The separation coefficient value is optimized to achieve the maximum utilization of these advantages. The experimental results verify the feasibility and effectiveness of the proposed hybrid CBPWM scheme.