• The Korean Journal of Applied Statistics
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• v.29 no.1
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• pp.171-180
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• 2016

Basel committee suggests using Value-at-Risk (VaR) and expected shortfall (ES) as a measurement for market risk. Various estimation methods of VaR and ES have been studied in the literature. This paper compares semi-parametric methods, such as conditional autoregressive value at risk (CAViaR) and conditional autoregressive expectile (CARE) methods, and a Gaussian quasi-maximum likelihood estimator (QMLE)-based method through back-testing methods. We use unconditional coverage (UC) and conditional coverage (CC) tests for VaR, and a bootstrap test for ES to check the adequacy. A real data analysis is conducted for S&P 500 index and Hyundai Motor Co. stock price index data sets.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.3
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• pp.27-33
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• 2007

This research investigated the effects of spherical and aspherical R.G.P lenses which was performed by optometrists in In-Cheon and Kyung-Gi region. This research survey included various questions such as the fitting status, after-care method, preliminary test. Results of the survey revealed that the optometriests sold the asperical and spherical lenses with a ratio of 7:3, respectively, and most of them did not cheked Topography, Fluorescein test by slit lamp biomicroscope, Tear Break up time test, Schirmer test and so on. And, with fitted R.G.P lenses symptoms like light odd-feeling, congestion, eye-stimulus, dimness and dryness were frequently reported. The purposes of this study are to search for the ideal fitting check of R.G.P lens and remind the most important preliminary test for contact lens fitting.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.9
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• pp.2331-2338
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• 1994

Experimental conditions of the optical shadow methods of caustics for measurement of the stress intensity factor and the J-integral in various materials(polycarbonate, PMMA, Al 5586D) are investigated. The necessary experimental requirements toe determine accurate values of the stress intensity factors and the J-integrals are described. The ratio of $r_o$ (radius of initial curve) to $r_p$ (plastic zone size) is selected as a parameter to verify the experimental limitation of the method of caustics in determination of fracture parameters. In this study, transmission caustics method was used for compact tension specimens made of polycarbonate and PMMA. while reflection caustics method was applied to c-shaped tension specimen made of Al 5586D. The appropriate ranges of $r_o/r_p$ tp determine accurate values of stress intensity factors were found to be 1.5~1.8. Existing experimental results have been obtained mainly by changing $r_p$ with different loads in $r_o/r_p$. However, in this study we could obtain varying $K_{caus}/K_{th}$ over the wide range of $r_o/r_p$ at fixed load conditions with newly designed optical arrangement. Thus, we could find the range in which theoretical and experimental results agree well each other by changing $r_o$ values only. In Al 5586D specimen, experimental caustics were located inside of the plastic zone, and $K_{caus}/K_{th}$ were found to be not unity in this range. It is found that $J_{caus}/J_{th}=1{\;}with{\;}r_o/t{\geq}0.8$ and the experimental plastic zone includes the contours of caustics.

• Journal of Korea Foundry Society
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• v.20 no.5
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• pp.330-335
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• 2000

Functional metal prototypes are often required in numerous industrial applications. These components are typically needed in the early stage of a project to determine form, fit and function. Recent R/P(Rapid Prototyping) part are made of soft materials such as plastics, wax, paper, these master models cannot be employed durable test in real harsh working environment. Parts by direct metal rapid tooling method, such as laser sintering, by now are hard to get net shape, pores of the green parts of powder casting method must be infiltrated to get proper strength as tool, and new type of 3D direct tooling system combining fabrication welding arc and cutting process is reported. But a system which can build directly 3D parts of high performance functional material as metal park would get long period of system development, massive investment and other serious obstacles, such as patent. In this paper, through the rapid tooling process as silicon rubber molding using R/P master model, and fabricate wax pattern in that silicon rubber mold using vacuum casting method, then we translated the wax patterns to numerous metal tool prototypes by new investment casting process combined conventional investment casting with rapid prototyping & rapid tooling process. With this wax-injection-mold-free investment casting, we developed new investment casting process of fabricating numerous functional metal prototypes from one master model, combined 3-D CAD, R/P and conventional investment casting and tried to expect net shape measuring total dimension shrinkage from R/P pare to metal part.

• Journal of Oral Medicine and Pain
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• v.10 no.1
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• pp.73-89
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• 1985

This study comprised 157 extracted teeth, 73 of the teeth originated from mates and 84 from females, the age range was 12-79 years. The correlation coefficient of each Gustafson's criteria in relation to age was carried out. Age estimation were performed on 157 teeth according to the method by Gustafson and by use of multiple regression, as used by Johanson, after evaluating the six criteria of Gustafson by multiple regression computer analysis. Two prediction formulas and standard deviations were compared with each other. The results were as follows : 1. The author found that six Gustafson's criteria had strong correlation with age except root resorption, and correlation coefficients were r = 0.79 (Transparent dentin), r=0.72 (Secondary dentin), r 0.69 (Periodontal change), r=0.63(Attrition), r = 0.39 (Root resorption), respecti vely. 2. The age estimation formula by Gustafson's method was calculated as follows: Y 8.88 + 3.52X r =0.87, r2 = 0.76, SD = 8.18, F = 483.56, P < 0.01 The age estimation formula by multiple regression was calculated as follows: Y 8.57 + 6.37T + 6.37T + 4.63P + 2.70S + 2.40C + 3.08A + 1.34R r= 0.89, r2 = 0.78, SD = 7.82, F = 91.62, P < 0.01, Durbin-Watson Coefficient = 1.09 3. In comparison of two estimation formulas, the formula by multiple regression, the method of Johanson, was found to be slightly more reliable than Gustafson's method. Gustafson's method SD = 8.18, Multiple regression (Johanson's method) SD = 7.82 4. It was reaffirmed that Gustafson's six criteria could be a independent variable in multiple regression analysis.

• Archives of Pharmacal Research
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• v.21 no.5
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• pp.543-548
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• 1998

We examined the immunological properties of the recombinant hepatitis B surface antigen (r-HBsAg) which was expressed in mammalian cell (C127). The cross-immunity of r-HBsAg and plasma-derived hepatitis B surface antigen (p-HBsAg) were tested using Western blotting and ELISA with guinea pig polyclonal antibody and naturally infected human-derived antibody and the both antigens show the same results in their response pattern and intensity, which indicate they have a good cross-immunity. from the measurement of $ED_{50}$ after formalin- or heat-inactivation, both r-HBsAg and p-HBsAg and p-HBsAg showed $ED_{50}$ of 0.2-0.3 in formalin-inactivaton, while r-HBsAg was 0.05-0.09 and p-HBsAg was 0.03-0.07 in heat-inactivation, which means heat-inactivation method is 3-4 times superior in immunogenicity. In the immunopersistency test performed in guinea pig for the period of 3 months with two different adjuvants, antibody titer was 34.2 with muramyl dipeptide adjuvant, which was 1.8 times greater than the antibody titer of 18.9 with $AIPO_{4}$ adjuvant. the mutagenicity of r-HBsAg has the same cross-immunity with p-HBsAg, and heat-inactivation method and muramyl dipeptide adjuvant allow development of r-HBsAg vaccine with excellent immunogenicity.

• Journal of Korean society of Dental Hygiene
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• v.15 no.5
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• pp.805-811
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• 2015

Objectives: The purpose of the study is to investigate the relationship between self-efficacy and learning attitude according to smoking experience in the middle school students. Methods: A self-reported questionnaire was completed by 608 middle school students in Gyeongnam from July 1 to 23, 2013. The questionnaire consisted of general characteristics of the subjects, smoking behavior, self-efficacy, and learning attitude. The questionnaire was adapted and modified from Kang, Park, and Koh. The self-efficacy was divided into general efficacy and social efficacy. The learning attitude was divided into attention concentration, learning method, and self learning. Data were analyzed using SPSS Win 21.0 program. Results: The nonsmoking students tended to have higher general efficacy and social efficacy than the smokers (p<0.01). The nonsmokers had more attention concentration in learning attitude than the smokers (p<0.001). The learning method (p<0.001) and self learning (p<0.001) showed the same results between the two groups. The smoking experience had the negative correlation with general efficacy (r=-0.164) and social efficacy(r=-0.154). The general efficacy is positively related to social efficacy (r=0.568). The smoking experience had the negative correlation to attention concentration (r=-0.235), learning method (r=-0.211) and self learning (r=-0.148). The attention concentration was positive relation with learning method (r=0.690) and self learning(r=0.662. The learning method had positive relation to self learning (r=0.764). Conclusions: The smoking students tended to have lower self-efficacy and learning attitude, so it is necessary to implement the smoking prevention program in the middle school students.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.1118-1128
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• 2015

The purpose of this study was to identify the relationships between life style, menstrual distress and coping method in nursing students. The survey was conducted with 199 nursing students at a nursing college in K city. Data were collected from November 19 to December 5, 2014, and analyzed using SPSS 18.0. Of the 197 respondents, 78.2% had menstrual distress and distress score was 2.7 on average. There was a significant negative correlation between life style and impaired concentration, life style and behavioral change, rest and impaired concentration. Alcohol was negatively correlated with menstrual distress, impaired concentration, behavial change, and negative affect. Positive correlation was observed between menstrual distress and coping. These results suggest that the development of educational program is needed to promote life style and thereby provide effective interventions for menstrual distress in college students.

• Journal of Korean Public Health Nursing
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• v.16 no.2
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• pp.254-270
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• 2002

This descriptive correlational study was conducted to identify the variables related to a health promoting lifestyle in women student of high school. 286 students were selected by a convenience sampling method. The data were collected by self - reported questionnaires from 10 to July 13, 2002. The data were analyzed by using descriptive statistics, pearson correlation coefficient, stepwise multiple regression with SPSS program. The result of this study were as follows: 1. The average score of health promoting behavior was 2.46 of a 4 point scale. Sanitary life(3.05), interpersonal support(2.80), alcohol & smoking(2.79) Self actualization(2.76), habit of meal(2.52), rest & sleeping(2.33) regulation of meal(2.30) stress management(2.05), health responsibility(1.91) were also analyzed. 2. Health promoting lifestyle showed significant positive correlations with self-esteem (r=0.446, p<0.00l), life orientation test(r=.493, P<0.0l) and score(F=6.157, P=0.002) 3. Perceived health state showed significant correlation with alcohol & smoking subscale(r=-.134, P<0.05) of health promoting lifestyle. Self-esteem showed significant correlation with total health promoting lifestyle(r=.538, P<0.01), and showed significant correlation self-actualization subscale(r=.657, P<0.01) health responsibility subscale (r=.272, P<0.01), food regulation subscale(r=.126, P<0.05), interpersonal relationship subscale (r=.468, P<0.0l), stress management subscale(r=.349, P<0.01) sanitary life subscale (r=.282, P<0.01) sleep & rest subscale(r=.123, P<0.05). Life orientation test showed significant correlation with total health promoting lifestyle(r=.493, p<0.01), self­actualization subscale(r=.643, p<0.01) health responsibility subscale(r=.192, P<0.0l), habit of meal subscale(r=.215, p<0.01), interpersonal relationship subscale(r=.423, p<0.01), stress management subscale(r=.345, p<0.01) sanitary life subscale(r=.191, p<0.01) sleep & rest subscale(r=.137, P<0.05). Stress response showed significant correlation with sleep & rest subscale(r=-.137, P<0.05) of health promoting lifestyle. 4. The combination of self-esteem. life orientation test explained $33.2\%$ of the variance in health promoting lifestyle. On the basis of the above findings. self-esteem and Life Orientation Test were identified as the variables which explained most of Pender's health promoting model. Nursing strategies enhancing self-esteem and Life Orientation Test which have a more significant effect on health promoting lifestyles should be developed.

• Journal of Korean Academy of Dental Administration
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• v.6 no.1
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• pp.11-18
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• 2018

The aim of this study was to evaluate the competency of the Easyperio test, a genetic test method based on real time PCR for the detection of bacteria that cause dental caries and periodontal disease. To verify the validity of this text, various dental health evaluations were administered to 33 boys between the ages of 12 to 14, as this age group commonly experiences dental caries. These evaluations included a dental caries experience survey, a first molar health evaluation, the Dentocult Streptococcus mutans (SM) strip mutans, the Dentocult Lactobacillus spp (LB) test, and the Easyperio test. The correlation coefficients between the level of the Dentocult SM strip mutans and the dental caries experience were DT (R=0.570, p=0.001), DMFT (R=0.376, p=0.031), and first molar health (R=-0.395, p=0.023). The correlation coefficients between the amount of SM in the Easyperio test and dental caries experience were DT (R=0.528, p=0.002), DMFT (R=0.369, p=0.035), and first molar health (R=-0.426, p=0.013). The correlation coefficients between the level of the dentocult SM strip mutans and the SM amounts of the Easyperio test were S.mi (R=0.564 p=0.001) and S.mu (R=0.621, p=0.002). The correlation coefficients between the level of the Dentocult LB test and the SM amount of Easyperio test was S.mi (R=0.495, p=0.003). In conclusion, Easyperio test may be an easy and effective method for the differentiation and diagnosis of dental caries through quantitative and qualitative analysis of oral bacteria.