• Journal of the Korean Society of School Health
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• v.15 no.1
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• pp.83-92
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• 2002

This study was undertaken to verify various relations between dental health belief and related behaviors in mothers and children. Data for this study were obtained by 264 pairs of 1st and 3rd grade elementary school children and their mothers by self developed questionnaire, The questionnaires are made on the general socio-economical characteristics, the oral health knowledge and the behaviors relative to the oral health and oral health education as to how mothers implement the oral health related activities for their children, while for the children, the questionnaires have been measured relative to the oral health beliefs and health behaviors for the children. The obtained results have shown that mothers become with more ages, the usefulness to prevent children's oral diseases becomes lower, and as much as mothers have higher education level, the sensitivity relative to the oral diseases has been measured low. To the degree that the students live well in economical respect, it has been found that they placed more importance on the oral health. As much as the number of mothers tooth brushing becomes made more in a day, the tooth brushing of the children becomes more that much, and also has higher level of oral health beliefs. The number of children to see dentists has been found high, and to the extent of increasing frequency of visiting dental clinics. As the number of mothers tooth brushing education becomes made more frequent for the children. Also, as mothers put more restriction on the sugar intakes by the children, they placed higher importance on the oral health for their children. In conclusion oral health behavior in mothers' influence on dental health belief of their children, it has been reviewed necessary to activate more the mother-children joint oral health education and oral health projects that mothers and children take part together, as well as to study more in accurate and systematic approaches through more comprehensive and various subjects and elements further in the future.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.4
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• pp.867-872
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• 2009

Peak expiratory flow rate(PEF) is one of the most important diagnostic parameters in spirometry. PEF occurs in a very short duration during the forced expiratory maneuver, which could lead to measurement error due to non-ideal dynamic characteristic of the transducer. In such case the initial slope of the flow rate signal determines the accuracy of the measured PEF. The present study considered this initial slope as a parameter to compensate PEF. The 26 standard flow rate signals recommended by the American Thoracic Society(ATS) were flown through the air flow transducer followed by simultaneous measurements of PEF and maximum transducer output$(N_{PEF})$. $N_{PEF}$-PEF satisfied a quadratic equation in general, however, two signals (ATS #2 and #26) having large initial slopes deviated from the fitting equation to a significant degree. The relative error was found to be in a linear relationship with the initial slope, thus, $N_{PEF}$ was appropriately compensated to provide accurate PEF with mean relative error less than only 1%. The 99% confidence interval of the mean relative error was less than a half of the error limit of 5% recommended by ATS. Therefore, PEF can be very accurately determined by compensating the transducer output based on the initial slope, which should be a useful technique for air flow transducer calibration.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.491-497
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• 2005

Brake system is indispensible functional part to the transportation machines such as railroad cars, and all of industrial machines. It is mechanical element to stop the movement or slow the speed, transforming kinetic energy of motion object into thermal energy through solid friction. According that recently the railroad cars have become high-speed, the technique in braking domain to secure the overall braking effort is making rapid progress. In particular, material development and manufacturing process are so important to secure friction performance, which is the core in braking performance of mechanical brake units. Wear of brake disk could mainly result in the diminishment of its life span due to thermal cracking, so the endurance against high temperature is required. On the other hand, in this case, the problem is that the side wear of pad, relative material is slightly increased because of enlargement of plastic deformation. It is necessary, therefore, to develop a disk material that will be used in the Tilting System mechanical brake units. The purpose of this paper is to make a study prior to developing brake disk of Tilting Train travelling at 200km/h and to propose the component of brake disk. Accordingly, I will conduct sufficient researches on technical documents of brake disk, that are basic documentations, analyze an impact on components, and further, considering braking degree of train, study for the basic proposal on brake disk's component of the train travelling at 200km/h, which has relatively minor influence of heat stress and maintains the friction. In this respect, I would like to investigate friction characteristics between disk and relative friction material via Test on some possible test segments, analyze and propose friction performance, temperature impact and so forth coming from the contact with pad, relative material to demonstrate the friction characteristics.

• Magazine of the Korean Society of Agricultural Engineers
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• v.30 no.4
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• pp.85-93
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• 1988

This laboratory study was carried out in order to produce fundamental data for analyzing salt movement and desalinization effects, using samples of silt loam soil collected in Gyehwado and Daeho reclaimed tidelans, and samples of silty clay loam soil collected in Kimie tideland. Desalinization experiments with gypsum treatment were performed to analyze changes of the hydraulicc conductivity with changes of the soil property and the salt concentration during the desalinization of reclaimed tideland soils by leaching through the subsufface drainage, and correlations between factors infl uencing the reclamation of salt affected soils were analyzed by the statistical method. The results were summarized as follows: 1. The reclaimed tideland soils used in this study were saline-sodic soils with the high exchangeable sodium percentage and the high electrical conductivity. 2. Changes of the hydraulic conductivity with the amount of leaching water and the leaching time elapsed were affected by the amount of gypsum except exchangeable sodium and clay contents. The regression equation between the depth of water leached per unit depth of soil (Dw / Ds : X) or the square root of the leaching time elapsed (T $^1$ $^2$ : X) and the relative hydraulic conductivity (HCr:Y) could be expressed in Y=a . bx. 3. The more exchangeable sodium and clay contents regardless of the amount of gypsum, the more the leaching time was required until a given volume of water was leached through the soil profile. The regression analysis showed that the relationship between the depth of water leached per unit depth of soil(Dw /Ds:X) and the square root of the leaching time elapsed(T$^1$$^2$ :Y) could be described by Y=a . Xb. 4. The hydraulic conductivity was influenced to a major degree by the salt concentration provided that the electrical conductivity was below 10 mmhos / cm during the desalinization of reclaimed tideland soils. The regression equation between the relative electrical conductivity ( ECr : X) and the relative hydraulic conductivity (HCr:Y) could be expressed in Y=a + b . X-$^1$. 5. In conclusion, the hydraulic conductivity, leaching requirements and the leaching time elapsed can be estimated when the salt concentration decreases to a certain level during the desalinization of reclaimed tidelands, and the results may be applied to the analysis of salt movement and desalinization effects.

• Nuclear Engineering and Technology
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• v.41 no.7
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• pp.875-884
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• 2009

We present three nuclear/hydrogen-related R&D activities being performed at KAIST: air-ingressed LOCA analysis code development, gas turbine analysis tool development, and hydrogen-production system analysis model development. The ICE numerical technique widely used for the safety analysis of water-reactors is successfully implemented into GAMMA, with which we solve the basic equations for continuity, momentum conservation, energy conservation of the gas mixture, and mass conservation of 6 species (He, N2, O2, CO, CO2, and H2O). GAMMA has been extensively validated using data from 14 test facilities. We developed a tool to predict the characteristics of HTGR helium turbines based on the throughflow calculation with a Newton-Raphson method that overcomes the weakness of the conventional method based on the successive iteration scheme. It is found that the current method reaches stable and quick convergence even under the off-normal condition with the same degree of accuracy. The dynamic equations for the distillation column of HI process are described with 4 material components involved in the HI process: H2O, HI, I2, H2. For the HI process we improved the Neumann model based on the NRTL (Non-Random Two-Liquid) model. The improved Neumann model predicted a total pressure with 8.6% maximum relative deviation from the data and 2.5% mean relative deviation, and liquid-liquid-separation with 9.52% maximum relative deviation from the data.

• Journal of the Korea Society of Computer and Information
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• v.15 no.9
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• pp.155-164
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• 2010

Until now, most of studies on Electronic Data Interchange(EDI) have been focused on the introduction of EDI and the performance of EDI. But recently, there have been increasing researches on diffusion of Electronic Data Interchange. The aims of this study are twofold. First, to find the impacts of various factors on EDI diffusion, second, to examine the relationship between EDI diffusion factors and EDI diffusion degree. To accomplish those aims of study, two kinds of methodologies are adopted in the studies, First, model building by wide investigation on previous papers, Second, empirical research for finding the determinants of diffusion of EDI. The results of testing the hypotheses of this research are summarized as follows. First, The important EDI diffusion variables influencing internal diffusion of EDI consist of top management support, scope for EDI, IS sophistication, compatibility, complexity, relative advantages, competition intensity and external pressure. Second, Top management support, scope for EDI, IS sophistication, compatibility, relative advantages, competition intensity and external pressure are associated with external diffusion of EDI. We are aware of the important fact that top management support, scope for EDI, IS sophistication, compatibility, relative advantage, competition intensity and external pressure were simultaneously associated with internal and external diffusion of EDI.

• Journal of the Korea Convergence Society
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• v.10 no.10
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• pp.259-266
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• 2019

The purpose of this study was to examine the need for changes in the administration strategies of hospitals which would be vital for building up competitiveness of hospitals amid the changes in medical market. For that, 20 experts with doctoral degree in public administration and business administration related to the field of hospital administration were selected as the sampling group in the survey. Regarding the method of AHP survey as in this survey. The results showed that the factors were important in the order of medical staff factor(ranked first), overall facility factor(ranked second), staff service factor(ranked third), and access factor(ranked fourth). Second, the relative importance was in the order of medical staff specialization(ranked first), medical staff diversity(ranked second), and medical equipment level(ranked third), regarding the relative importance for general hospital development strategy and the complex weighted value for relative importance.

• Knowledge Management Research
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• v.22 no.2
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• pp.289-300
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• 2021

Proptech, which has applied information technology to the real estate market, is leading real estate transaction innovation by presenting various value creation models. This study categorizes and understands values that are created and shared in proptech-based businesses, and develops evaluation data that reflects the relative importance of individual value areas. To this end, the dimension of value creation of proptech was hierarchically constructed, and the degree of relative value creation of the sub-industries of the proptech industry was evaluated. In order to grasp the relative importance of the proposed indicators, AHP analysis was conducted for industry and academic experts. In the first stage, intangible values, relational values, and advanced values were presented. It was derived as weights between indicators through two-way comparison. This study aims to improve and develop the value-creation capability of the entire Korean proptech ecosystem in the future by evaluating the value-created competence of each sector of the proptech industry.

• Restorative Dentistry and Endodontics
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• v.27 no.1
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• pp.77-86
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• 2002

Current composites are made with dimethacrylate monomers and silane-treated silica microfillers, either alone or with silane treated glass fillers The main reasons for clinical failure of dental composites are secondary caries, wear and fracture. Most of practitioner want to get a composite which is more tougher under occlusal stress, less polymerization contraction, and better handling properties in application clinically. The aim of this study was to investigate the influence of resin matrix with various flows on the physical proper-ties such as fracture toughness and degree of conversion of the experimental resins. It was hypothesized that flexible or tough resin composites can be designed by judicious choice of monomer composition Various flow resin matrices containing Bis-GMA, UDMA, and TEG-DMA were made by altering the pro-portion of the monomers. After the unfilled resins were light-cured for different light intensity, the fracture toughness(K$_{1c}$) was measured according to ASTM standard using the single edge notched geometry, and degree of conversion(DC) was measured by FTIR. And experimental composites were formulated with variations in the proportion of silanated quartz and strontium glass fillers as 60, 75, and 77wt%. Also, the physical properties of composites with various filer contents were evaluated as same manner. All resulting data were compared by ANOVA/Tukeys test at 0.05 level. The results were as follows; 1. The degree of conversion of high flow resin containing less Bis-GMA was higher than that of low flow unfilled resin 2. While the degree of conversion of unfilled resin was increased according to light intensity for polymerization, there was no significant increase with moderate and high light intensity. Also, the fracture toughness was not increased by high light intensity. 3. The fracture toughness was high in the low flow unfilled resin containing higher contents of Bis-GMA. 4. There was a significant increase for fracture toughness and a tendency for degree of conversion to be reduced when the content of fillers was increased. 5. In the experimental composites, the flow of resin matrix did not affected on the fracture toughness, even, which was decreased as increase of viscosity. These results showed that the physical properties of a dental composite could be attributed to the flow of resin matrix with relative content of monomers. Specific combination of resin monomers should be designed to fulfil the needs of specific indication for use.

• Health Policy and Management
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• v.8 no.2
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• pp.149-165
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• 1998

The purpose of this study is to examine the effect of the health status on the quality of life of the rural elderly, and to examine the conditional effect of socialsupport for that influence. 'Quality of life' used in this study was defined by unidimensional approach. The data were collected by conducting individual interviews with 296 rural elderly people aged 60 and the above who were living in one township of Kangwondo, between the time period of October and November 1995. The main findings are as follows: 1. Hierarchical regression analyses were carried out to examine the relative contribution of three set of variables on the quality of life. The first step, which included sociodemographic factors showed that the coefficient of determination (R$^{2}$) was 8% and income was a statisically significant variable. The second step, by adding health related factors, revealed that the R$^{2}$ was increased to 34% by 26% point and the degree of health recognition was the statistically significant variable. The third step, by projecting additionall social support related variables revealed that the R$^{2}$ was 42% 2. The conditional effect of social support was analyzed to examine the influence the health status has on the quality of life. The results are as follows: 1) The IADL and the degree of social contact interacted, resulting in that the higher degree of social contact boosted the stronger effect of IADL. 2) The effect of subjective health recognition on the quality of life is depended upon degree of family ontact. 3) The effect of eyesight on the quality of life is depended upon degree of satisfaction in social relation. The lower the degree of social support was, the bigger the influence of health related variables affecting quality of life became. This study explains that health status is a major factor in predicting the quality of life of the aged. Particularly the subjective health recognition was an important factor as the perception of quality of life.