• The Journal of Korean Academy of Prosthodontics
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• v.47 no.1
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• pp.1-11
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• 2009

Statement of problem: There are two methods of color choice for the esthetic restoration. One is visual shade matching which draws a comparison between shade guide and teeth in dentist's own eye and the other is using a digital shade analysis system recently introduced. Although the visual shade matching has a lot of problems, decision of color by this visual shade matching and the ways of expression for the decided color are still applicable to clinical dentistry. Purpose: This study is designed to investigate shade guides used in the dental clinics and laboratories have the same value using ShadeEye-$NCC^{(R)}$ dental chroma meter (Shofu Inc., Kyoto, Japan) using shade guide are evaluated. Material and methods: At the first experiment, eight Vita Lumin Vacuum shade guides (Vident Inc., California, USA) were collected from the dental clinics. A1 and B1 shade tabs are chosen and the colors are analyzed five times each in both tooth and porcelain modes by digital shade analysis system, ShadeEye-$NCC^{(R)}$. In the second experiment, twelve Vita shade guides using practically in the dental clinics and laboratories were collected and also A1 and B1 shade tabs are chosen and the colors of A1 and B1 are analyzed one time each in both tooth and porcelain modes by ShadeEye-$NCC^{(R)}$. Results and conclusion: There were significant differences among eight shade guides in terms of shade (chroma), value and hue in both of A1 and B1 (P<.05). Shade guides using in present both dental clinics and laboratories did not show significant differences, except A1 in the porcelain mode, it showed significant differences (P<.05) in the shade even though the shade tab has the same name.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.1
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• pp.29-38
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• 2009

Statement of problem: A casting connection technique is widely used for repair, correction and addition to base metal framework. However, a casting connection technique may increase the risk of failure in clinical situations when high stresses exist. Purpose: The purpose of this study was to investigate the mechanical retentive groove design comparatively to increase the joint strength by using the three-dimensional finite element analysis model of a 3-unit fixed partial denture. Material and methods: Ten finite element models were constructed. (Model A: One retentive groove, Model B: Two retentive grooves, Model C: Three retentive grooves, Model D: Four retentive grooves, Model E: One horizontal groove and two vertical grooves, Model F: Two horizontal grooves and one vertical groove, Model G: One groove with the enlarged dimension, Model H: Two grooves with the enlarged dimension, Model I: One groove with the increased height, Model J: One groove with the increased width of base). The vertical force was applied to the mesial and the distal fossa to the casting connection of mandibular first molar. Results: The main factors, affecting joint strength of casting connection were both the retention between the primary cast and the secondary cast and the thickness of the primary cast remaining after preparing retentive groove. The increase of retentive force, according to the numbers and the dimension of retentive groove had an effect on distributing stress. However, in some cases, the increase of retentive force resulted in the increase of stress by reducing thickness of the primary cast in the connection area. Conclusion: The design of retentive groove that limits number of retentive groove for metal thickness and increases the depth of retentive groove for retention is highly recommended.

• Journal of Bio-Environment Control
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• v.23 no.4
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• pp.293-302
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• 2014

This study was carried out to develop rain shelter which can make an appropriate size and environment for Chinese cabbage rainproof cultivation. Fifty three farms with chinese cabbage rainproof cultivation system have been investigated to set up width and height of rain shelter. Mostly the width of 6m was desired for rain shelter and the height of 1.6m for their eaves, so these values were chosen as the dimensions for rain shelter. After an analysis of their structural safety and installation costs by the specifications of the rafter pipe, Ø$25.4{\times}1.5t$ and 90cm have been set as the size of rafter that such size costs the least. This size is stable with $27m{\cdot}s^{-1}$ of wind velocity and 17cm of snow depth. Therefore it is difficult to apply this dimension to area with higher climate load. In order to sort out such problem, the rain shelter has been designed to avoid damage on frame by opening plastic film to the ridge. Once greenhouse band is loosen by turning the manual switch at the both sides of rain shelter and open button of controller is pushed then switch motor rises up along the guide pipe and plastic film is opened to the ridge. Chinese cabbage can be damaged by insects if rain shelter is opened completely as revealed a field. To prevent this, farmers can install an insect-proof net. Further, the greenhouse can be damaged by typhoon while growing Chinese cabbage therefore the effect of an insect-proof net on structural safety has been analyzed. And then structural safety has been analyzed through using flow-structure interaction method at the wind condition of $40m{\cdot}s^{-1}$. And it assumed that wind applied perpendicular to side of the rain shelter which was covered by insect-proof net. The results indicated that plastic film was directly affected by wind therefore high pressure occurred on the surface. But wind load on insect-proof net was smaller than on plastic film and pressure distribution was also uniform. The results of structural analysis by applying pressure data extracted from flow analysis indicated that the maximum stress occurred at the end of pipe which is the ground part and the value has been 54.6MPa. The allowable stress of pipe in the standard of structural safety must be 215 MPa or more therefore structural safety of this rain shelter is satisfied.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.17 no.3
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• pp.85-91
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• 2017

Purpose: The aim of this study was to describe the clinical and biochemical features as well as the molecular analysis of a newly diagnosed illustrative case with ML II and to analyze the clinical features of 11 Korean patients with ML II/III. Method: Including a newly diagnosed patient, total 11 patients in 10 families were diagnosed as ML II (n=7) or ML III (n=4) were enrolled in the study. A diagnosis of ML II or III was made by demonstrating increased lysosomal enzyme activities in the plasma and sequence analysis of GNPTAB with characteristic clinical features. Result: A illustrative case of ML II patient was a 17 month-old boy showing characteristic facial appearance, multiple joint contractures with cardiac involvements. The enzyme assay showed increased lysosomal enzyme activities in the plasma. We identified compound heterozygous mutations in GNPTAB sequence analysis, including a frameshift (c.3428dupA [pAsn1143Lysfs*3]) and a nonsense variant c.673C>T (p.Gln225*). In total 11 patients with ML II/III, the patients with ML II showed severe growth retardation (height standard deviation score -3.2 [${\pm}1.5$]), compare to patients with ML III. Furthermore, patients with ML II patients had serious cardiac problem (n=4), hepatomegaly (n=3) and underwent tracheostomy (n=3) with further respiratory support due to respiratory distress. To improve osteoporosis and bone pain, all patients with ML III and four of 7 patients with ML II treated with intravenous pamidronate. Conclusion: Here we showed a newly diagnosed case of ML II and clinical features of 11 Korean patients with ML II or III. These data could be helpful for further diagnosis of mucolipidosis, a rare inherited metabolic disease, in Korea.

• Korean Journal of Child Education & Care
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• v.18 no.2
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• pp.85-102
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• 2018

The purpose of this study is to determine the working conditions and demands of the assistant workforce at childcare centers, and to provide suggestions on policies for childcare teachers. To achieve the purpose of the study, a total of 190 assistant teachers, nursing helpers, alternative teachers and others were surveyed online during the month of August 2017. The survey examined the employment route and working motives, working conditions and environment, job and educational difficulties for analyzing the work conditions and demands of ancillary staff. For the analysis method, SPSS 12.0 was used to analyze frequency and difference. The main findings are as follows. First, childcare center assistants were able to work at their respective times, making it mandatory for them to enter the workforce, and making job openings for ancillary teachers. Second, 73.7% said the daily working hours were '4 hours to 8 hours' under the conditions and 57.9% said 'More than 510,000 won to less than 1 million won.' Average amount of rest time per day was about 30 minutes, and 17% had no rest periods. Third, based on the job and education status, ancillary personnel performed "infant and child guidance and interaction", "Cleaning and cleanliness related tasks" most actively, and "care for cleaning and cleanliness" and "care for morning and night care". Fourth, in the job trouble and difficulty, ancillary staff found it difficult to satisfy with wage related complaints and job insecurity, and the reason for agreeing to the non-regular workforce becoming a regular worker was found to be due to the stability of employment. Lastly, the most urgent tasks to solve the problem of non-regular workers were to fill the wage gap between regular and irregular workers, shorten the working hours and improve the working conditions. The policy implications are presented based on the above findings.

• Hwankyungkyoyuk
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• v.7 no.1
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• pp.106-122
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• 1994

The purpose of this study to investigate the awareness of environmental management knowledge and behavior and the effect of independent variables (The environmental management behavior of housewives are composed of five activities-clothing, eating, housing, buying, family management. The independent variables are composed of objective variable and subjective variable). The Research Questions are as follows; 1. Are there significant differences in the housewife's awareness of the environmental management knowledge according to the objective variable and the subjective variable? 2. How much are the effects of related variables on the awareness of environmental management knowledge? 3. Are there significant differences in the housewife's environmental management behavior according to objective variable and subjective variable and awareness of environmental management knowledge? 4. How much are effects of related variables on the housewife's environmental management behavior? For these purpose, a theoretical framework was developed by literature review and applied to empirical test. The data was collected through the questionnaire those respondents were 477 housewives in seoul. It was analyzed by various statistical methods such as Frequency. Percentile, GLM, F-test, T-test, Duncan's Multiple Range Test, Pearson's Correlations Analysis Simple Regression Analysis, and Multiple Regression Analysis. The results of this research are as follows; 1. The awareness of environmental management knowledge had significant differences according to the variables such as housewife's age, husband's job, family number, education experience of environment, frequencies of contracting mass media, the perceived adequacy of resources, social-altruistic orientation. 2. Among all of these variables affecting the awareness of environmental management knowledge, the perceived adequacy of resources had the highest effects and the next were family number, social-altruistic, type of residence in order. 3. Total Environmental management behavior of housewives had significant differences according to the variables such of environment, frequencies of contracting mass media, the satisfaction of household labor, the perceived adequacy of resources, biospheric orientation, social-altruistic orientation, egoism orientation, the awareness of environmental management knowledge. The clothing, eating, housing, family management behavior had the high level, the buying management behavior had the average level. The clothing, eating, housing, buying, family management behavior had significant differences according to the variables such as the satisfaction of household labor, the perceived adequacy of resources, biospheric orientation, social-altruistic orientation, egoism orientation, the awareness of environmental management knowledge. In particular, the clothing, eating, housing, buying management behavior had significant differences according to the variables such as education experience of environment. And the housing, buying management behavior had significant differences according to the variables such as frequencies of contracting mass media. 4. Among all of theses variables affecting environmental management behavior, the most influence variables was awareness of environmental management knowledge and the next were influence of housewife's job, biospheric orientation, the satisfaction of household labor, education experience of environment, frequencies of contraction mass media, egoism orientation in order. Among all of theses variables effecting the clothing, eating, housing, buying management behavior the variables affecting the family management behavior, the most influences variables was housewife's job. In the result of analysing the housewife's environmental management behavior and awareness of environmental management knowledge, influences of education experience of environment had the highest effect and frequencies of contracting mass media may more influencial than other variables. And Concrete and systematic knowledge and technique of environmental education is requisite. The result of this study could be attributed to develop the efficient environmental information. More emphasis should be given to environmental education and a long range environmental policy. in particular, environmental education be effectively related to environmental behavior, life-education and systematic support must be provided. In addition, further study of environmental problem is needed for and application of various theoretical approaches and research method.

• Journal of Korean Society of Transportation
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• v.35 no.4
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• pp.360-373
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• 2017

The BTO-a projects is the types, which has a demand risk among the type of PPP projects in Korea. When demand risk is realized, private investor encounters financial difficulties due to lower revenue than its expectation and the government may also have a problem in stable infrastructure operation. In this regards, the government has applied various risk sharing policies in response to demand risk. However, the amount of government's risk sharing is the government's contingent liabilities as a result of demand uncertainty, and it fails to be quantified by the conventional NPV method of expressing in the text of the concession agreement. The purpose of this study is to estimate the value of investment risk sharing by the government considering the demand risk in the profit sharing system (BTO-a) introduced in 2015 as one of the demand risk sharing policy. The investment risk sharing will take the form of options in finance. Private investors have the right to claim subsidies from the government when their revenue declines, while the government has the obligation to pay subsidies under certain conditions. In this study, we have established a methodology for estimating the value of investment risk sharing by using the Black - Scholes option pricing model and examined the appropriateness of the results through case studies. As a result of the analysis, the value of investment risk sharing is estimated to be 12 billion won, which is about 4% of the investment cost of the private investment. In other words, it can be seen that the government will invest 12 billion won in financial support by sharing the investment risk. The option value when assuming the traffic volume risk as a random variable from the case studies is derived as an average of 12.2 billion won and a standard deviation of 3.67 billion won. As a result of the cumulative distribution, the option value of the 90% probability interval will be determined within the range of 6.9 to 18.8 billion won. The method proposed in this study is expected to help government and private investors understand the better risk analysis and economic value of better for investment risk sharing under the uncertainty of future demand.

• Journal of agricultural medicine and community health
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• v.35 no.2
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• pp.151-164
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• 2010

Objective:Korea has 3,170 islands with about 188,000 inhabitants. These inhabitants' needs for health services might go unmet because of geographic isolation, slimmer availability of health services, and higher proportion of the elderly compared with the mainland population. Unmet health service needs might result in serious health problems for these island residents. Therefore, the purpose of this study was to investigate their unmet health service needs and related factors from population of Nowha island. Methods: The survey was conducted from July 30 to August 1 by trained interviewers. Target population were residents in Nohwa island and the sampling method was incomplete quota sampling. General characteristics, socioeconomic status, utilization of health service, and unmet medical service needs were investigated. First univariate and then multivariate logistic analyses were done for the statistical analysis. Results: 324 residents were surveyed and the proportion of unmet health services needs was 26.5%. People living alone and of female sex had increased health services needs based on univariable analysis. From the multivariate analysis, those living alone increased the health services needs. Self-determined low socioeconomic status and medical aid increased the proportion of unmet medical needs, but these were not statistically significant. Conclusion:In Nowha island, those who are elder, and of lower socioeconomic status had much higher unmet medical needs. The results suggest the need for more social support by qualified health services to solve this unmet medical needs problem.

• Journal of Korean Home Economics Education Association
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• v.24 no.1
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• pp.1-20
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• 2012

The study, published in the 2007 revised curriculum of Practical Arts and Technology and Home Economics textbook(16 species) of the 'human development and family members' area of learning content elements were analyzed. This analysis was conducted in order to evaluate that the 2007 revised curriculum of Practical Arts(Technology and Home Economics) has been made well Articulations. The criteria of Articulations is "Development of learning content, Repeating, Gaps, Reduction. Content criterias is 'human development and family' area. These include "human development, human relationships, marriage and family life, caring for family members and family welfare" of the four criteria and 14 content elements. The results of this analysis, the first content elements is "process of human development, characteristics of human development, family relationships, communication, dating and partner selection, the significance of marriage and family, understanding the basic concepts of family, family change and family problem solving". There was no content elements. content element is 'friendship'. content elements is 'Characteristics of human development', 'understanding of sex and pregnancy and childbirth'. Thus, in the new curriculum, a review of these Articulations are required. Especially, the 'friendship' and 'understanding of sex and pregnancy and childbirth' of the content element should be noted in the curriculum configuration because of content elements be Analyzed as or . Also 'values about marriage change' importance in the low fertility society is a big learning content elements need repeating. However, textbooks should reflect differences in the configuration will hakgyogeupgan. Meanwhile, 'changes in values about marriage' that it is necessary to deal with the repeatedly because of recentely society is The low fertility society, However, for this content element based on the differences between school level to appear the contents of textbooks, the textbook screening process will be provided with the correct guidance.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.5
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• pp.479-489
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• 2008

Statement of the problem: Under anatomical limitations on maxillary posterior region, a poor crown-to root ratio acting on dental implants can result in undesirable stress in surrounding bone, which in turn can cause bone defects and eventual failure of implants. Purpose: The purpose is to compare stress distribution due to different crown-root ratio and effect of splinting between natural teeth and implants in maxillary molar area under different loads. Material and methods: Analysis of stress arising supporting bone of the natural teeth and the implant was made with 3-dimensional finite element method. The model simulated naturel teeth was made with 2nd premolar and 1st molar in the maxillary molar region (Model T). The model simulated implants placed on same positions with two parallel implants of Straumann Dental Implant cemented abutment (Model I). Each model was designed in different crown-root ratio (0.7:1, 1:1, 1.25:1) and set cement type gold crown to make it non-splinted or splinted. After that, 300 N force was loaded to each model in five ways (Load 1: middle of occlusal table, Load 2: middle of buccal cusp, Load 3: middle of lingual cusp, Load 4: horizontal load to buccal cusp of anterior abutment only, Load 5: horizontal load to middle of buccal cusp of each abutment), and stress distribution was analyzed. Results and conclusion: On all occasions, stress was concentrated at the cervical region of the implant. Under load 1, 2 and 3, stress was not increased even when crown-root ratio increases, but under load 4 and 5, when crown-root ratio increases, stress also increased. There was difference in stress values between natural teeth and implants when crown-root ratio gradually increases; In case of natural teeth, splinting decreased stress under vertical and horizontal loads. In case of implants, splinting decreased stress under vertical loads 1,2 and 3, but increased maximal stress under loads 2 and 3. Under horizontal loads, splinting decreased stress, however the effect of splinting decreased under load 5 than load 4. Furthermore, the stress was increased, when crown-root ratio is 1.25:1. Clinical implications: This limited finite element study suggests that the stress on supporting bone may be increased under non-axial loads and poor crown-root ratio. Under poor crown-root ratio, excessive stress was generated at the cervical region of the implant, and decreased splinting effect for stress distribution, which can be related to clinical failure.