• Korean Journal of Biological Psychiatry
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• v.6 no.2
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• pp.219-226
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• 1999

Objectives : The aims of this study were to evaluate changes in plasma superoxide dismutase(SOD) activities in alcohol depedence, to find out variables to influence on the SOD activities, and finally to identify the correlation of SOD activities with the alcohol-associated cognitive disorders. Methods : For 24 male alcoholics and 21 healthy male controls, plasma SOD activities were measured by spectrophotometry on 1-2 wks after alcohol withdrawal. Structured interviews and laboratory tests were also performed. Results : 1) Upon comparing SOD activities between controls and alcoholics, the SOD activities were significantly(p<0.01) lower in alcoholics($0.308{\pm}0.140$ units/mL) than in healthy controls($0.313{\pm}0.086$ units/mL). 2) Upon comparing SOD activities according to the presence of alcohol-related cognitive disorders, the SOD activities were significantly(p<0.05) lower in alcoholics with cognitive disorders($0.247{\pm}0.049$ units/mL) than in alcoholics without cognitive disorders($0.317{\pm}0.148$ units/mL). 3) Upon comparing SOD activities according to the presence of alcoholic polyneuropathy or alcohol withdrawal seizure, the SOD activities showed no significant differences between alcoholics with polyneuropathy or epilepsy and those without. 4) Upon analyzing variables influencing on the SOD activities in alcoholics, the SOD activities had the negative correlation with hemoglobin(${\gamma}=-0.433$) and severity of alcohol withdrawal symptoms(${\gamma}=-0.375$). 5) Upon comparing variables according to the presence of alcohol-related cognitive disorders, the occurrence of alcoholic polyneuropathy(p<0.05) and blood phosphorus concentrations(p<0.01) were significantly higher in alcoholics with cognitive disorders than those without. 6) Upon analyzing an association between SOD activities and variables in alcoholics with cognitive disorders, the SOD activities were positively correlated with the onset age(${\gamma}=0.995$), and negatively correlated with the severity of alcohol withdrawal symptoms(${\gamma}=-0.996$). Conclusions : Lower SOD activities in alcohol dependence suggested alcohol-associated cognitive disorders and alcohol withdrawal symptoms might be caused by oxidative stress.

• Journal of the Korean Society of School Health
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• v.16 no.2
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• pp.45-55
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• 2003

This study was focused on comparing the knowledge, attitudes and experiences in sex and the needs for sex education of nursing students and non-nursing students. The subjects of this study were 403 female students who attended 4 universities in Busan. The data was collected from November 2002 to December, and analyzed by frequency, percentage, mean, standard variance, t-test and Chi-square. The results were as follows: 1. The mean score of sex knowledge of the nursing students was 13.29 and the non-nursing students's was 11.11. There was a difference(p=0.000) between nursing and non-nursing students in sex knowledge. 2. The mean score of sex attitude of nursing and non-nursing students was 25.64, 26.65 respectively. There was no statistical difference. 3. 61.8% of the nursing students and 62.3% of the non-nursing students had experienced a relation with the opposite sex. Kissing experience was 59.9%, 61.8% and masturbation was 9.5%, 9.2% respectively. Sexual intercourse was 5.3%, 11.9% and contraception was 1.9%, 8.2% respectively. Among these experiences, sexual intercourse and contraception experience rate were different(p=0.017, p=0.002 respectively) between nursing and non-nursing students. 4. Of 19 sexual education contents, only 'the dignity of life' showed a difference. That is, more nursing students(92.9%) wanted to know about 'the dignity of life' than non-nursing students(85.7%). Among the respcndent's needs on the sexual education contents, 'Contraception' was rated first and followed by 'Sex psychology of men and women', 'Pregnancy', 'Prevention of sexual crime' and 'Sexually transmitted diseases'. Most of the respcndents(95.8%) wanted sex education introduced in the :first year of university, and presented as a special class. Specifically, 50.0% of the students wanted the education to be more realistic and systemic. With the above results, when university faculties are sexual educating to university students, they have to aware of the difference of target students. And they need to stress more realistic and specific aspect of sexual education learning rather than theoretical teaching.

• Restorative Dentistry and Endodontics
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• v.35 no.1
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• pp.51-58
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• 2010

Dental composites have improved significantly in physical properties over the past few decades. However, polymerization shrinkage and stress is still the major drawback of composites, limiting its use to selected cases. Much effort has been made to make low shrinking composites to overcome this issue and silorane-based composites have recently been introduced into the market. The aim of this study was to measure the volumetric polymerization shrinkage kinetics of a silorane-based composite and compare it with conventional methacrylate-based composites in order to evaluate its effectiveness in reducing polymerization shrinkage. Five commercial methacrylate-based (Beautifil, Z100, Z250, Z350 and Gradia X) and a silorane-based (P90) composites were investigated. The volumetric change of the composites during light polymerization was detected continuously as buoyancy change in distilled water by means of Archemedes' principle, using a newly made volume shrinkage measurement instrument. The null hypothesis was that there were no differences in polymerization shrinkage, peak polymerization shrinkage rate and peak shrinkage time between the silorane-based composite and methacrylate-based composites. The results were as follows: 1. The shrinkage of silorane-based (P90) composites was the lowest (1.48%), and that of Beautifil composite was the highest (2.80%). There were also significant differences between brands among the methacrylate-based composites. 2. Peak polymerization shrinkage rate was the lowest in P90 (0.13%/s) and the highest in Z100 (0.34%/s). 3. The time to reach peak shrinkage rate of the silorane-based composite (P90) was longer (6.7 s) than those of the methacrylate-based composites (2.4-3.1 s). 4. Peak shrinkage rate showed a strong positive correlation with the product of polymerization shrinkage and the inverse of peak shrinkage time (R = 0.95).

• Journal of the Korea Concrete Institute
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• v.28 no.5
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• pp.581-592
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• 2016

Tensile constitutive stress-strain model of steel fiber reinforced concrete (SFRC) in fib MC2010 was investigated. In order to model tensile behavior of SFRC, three point loading flexural tests were conducted on notched small beams according to BE-EN-14651. Design parameters for the constitutive model were determined from the flexural tests. Flexural test and finite element analysis were conducted on large SFRC beam without steel reinforcements and compared with each other. In addition, parametric study on the effect of compressive and tensile model, and characteristic length on flexural behavior of the SFRC beam was conducted also. In results, pre-peak load-displacement curves from the FE analysis was close to experimental curves but significant difference was shown in post-peak behavior. The reason of the difference is originated from the fact that the fiber distribution and orientation were not being properly considered in the MC2010 model. This study shows that modification and detail explanations on the orientation factor K in MC2010 might require to better reproduce the behaviour of large scale SFRC beams.

• The Journal of Korean Society for School & Community Health Education
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• v.3
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• pp.1-13
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• 2002

Female university students generally have a lower intake of nutrition compared to other age groups due to their adverse interests in their appearance. Drinking, smoking, too much weight control, accumulation of psychological and physical stress are causes of inadequate diet. The result is deterioration of hair health. Establishment of good diet and hair care is the foundation of a healthy hair in adulthood. For this reason, there is a great need for a healthy hair care. The data from a questionnaire survey was analyzed with 800 female undergraduate students responding. Seventeen universities were included in the study, 8 of which were from Seoul, 6 from other large cities and 3 from smaller towns. The objective of this study is to investigate the correlations of these factors and to provide preliminary data for developing an effective hair care education program. Results include the following: 1. Knowledge score of hair care based on general characteristics were higher for students in larger cites compare to small cites or regions. Also, students in higher academic year, more allowance, interest in their apparence and family income showed higher knowledge in this field. These factors had meaningful effect on the statistics of this study. 2. Attitude score towards hair care based on general characteristics were higher for students in larger cites compare to small cites or regions. Also, students in higher academic year, more allowance, interest in their apparence and family income showed higher knowledge in this field. These factors had meaningful effect on the statistics of this study. 3. Behavior score towards hair care was higher for students with greater family income, allowance, interest in appearance. These factors had meaningful effect on the statistics of this study. 4. The correlation study between knowledge, attitude and behavior showed that higher the knowledge and attitude, better the behavior. 5. The analysis of factors effecting hair care behavior showed that interest in health, acknowledgement of current hair condition, total family income were a viable factor in predicting hair care behavior. The predictability of regression model is 38.9 %($R^2$) Therefore, in order to maximize the hair care behavior, consistent and systematic study should be earned out to develope an effective education program to improve health interest.

• Journal of Navigation and Port Research
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• v.30 no.6 s.112
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• pp.439-446
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• 2006

In ship structures many of the structural plates have cutouts, for example, at inner bottom structure, girder, upper deck hatch, floor and dia-frame etc. In the case where a plate has a cutout it experiences reduced buckling and ultimate strength and at the same time the in-plane stress under compressive load produced by hull girder bending will be redistributed In general, actual ship structure adopted reinforcement of stiffener around the cutout in order to preventing from buckling so it need to examine a buckling and ultimate strength behaviour considering a cutout because In many ship yards used class rule for calculating buckling strength but it is difficult to evaluate perforate stiffened plate with random size. In the present paper, we investigated several kinds of perforated stiffened model from actual ship and then was performed finite element series analysis varying the cutout ratio, web height, thickness and type of cross-section using commercial FEA program(ANSYS) under compressive load.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.22-30
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• 2017

This paper presents the research results of a light weight through topology optimization and structural safety evaluation through structural analysis of a pressure system structure installed in an off-shore plant. Conducting a structure design according to the wind load and the dynamic load at sea in addition to a self-load and structure stability evaluation are very important for structures installed in off-shore plants. In this study, the wind and dynamic load conditions according to the DNV classification rule was applied to the analysis. The topology optimization method was applied to the structure to obtain a lightweight shape. Phase optimization analysis confirmed the stress concentration portion. Topology optimization analysis takes the shape by removing unnecessary elements in the design that have been designed to form a rib shape. Based on the analysis results about the light weight optimal shape, a safety evaluation through structural analysis and suitability of the shape was conducted. This study suggests a design and safety evaluation of an off-shore plant structure that is difficult for structural safety evaluations using an actual test.

• Journal of Korean Society of Steel Construction
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• v.28 no.3
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• pp.195-202
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• 2016

In this study, it is carried out to analyze the international design standards such as Eurocode 8, API 650, NZSEE and etc for the seismic design of steel liquid storage tanks. From the comparison and analysis, the data for the required parameters and factors are provided for the establishment of Korean seismic design standard for steel liquid storage tanks. The simplified mechanical models have been presented for the seismic design of steel liquid storage tanks in all design standards and the parameters of mechanical models in design standards have similar values. Although the models for the seismic design of steel liquid storage tanks are similar in design standards, design approaches are given differently in accordance with the design methods, allowable stress design or limit state design. Therefore it is not easy to compare seismic forces presented in design standards directly. After comparison of design standards, it is concluded that establishment of Korean design standard for the seismic design of steel liquid storage tanks is necessary.

• Journal of Dental Rehabilitation and Applied Science
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• v.19 no.4
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• pp.269-279
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• 2003

This study investigated the mechanical properties of precious metal-ceramic alloy joined by the laser-welding and the soldering compared with the parent metal. Twenty-four tensile specimens were cast in precious metal-ceramic alloy and divided into three groups of eight. All specimens in the control group(group 1) were left in the as-cast condition. Group 2 and 3 were the test specimens, which were sectioned at the center. Eight of sectioned specimens were joined by soldering with a propane-oxygen torch, and the remaining specimens were joined by laser-welding. After joining, each joint diameter was measured, and then tested to tensile failure on an Instron machine. Failure loads were recorded, and then fracture stress(ultimate tensile strength), 0.2% yield strength and % elongation calculated. These data for three groups were subjected to a one-way analysis of variance(ANOVA). Neuman-Keuls post hoc test was then used to determine any significant differences between groups. The fracture locations, fracture surfaces were examined by SEM(scanning electron microscope). The results were as follows: 1) The tensile strength and 0.2% yield strength of the soldered group($280.28{\pm}49.35MPa$, $160.24{\pm}26.67MPa$) were significantly less than both the as-cast group($410.99{\pm}13.07MPa$, $217.82{\pm}17.99MPa$) and the laser-welded group($383.56{\pm}59.08MPa$, $217.18{\pm}12.96MPa$). 2) The tensile strength and 0.2% yield strength of the laser-welded group were about each 98%, 99.7% of the as-cast group. There were no statistically significant differences in these two groups(p<0.05). 3) The percentage elongations of the soldered group($3.94{\pm}2.32%$) and the laser-welded group($5.06{\pm}1.08%$) were significantly less than the as-cast group($14.25{\pm}4.05%$) (p<0.05). 4) The fracture of the soldered specimens occurred in the solder material and many porosities were showed at the fracture site. 5) The fracture of the laser-welded specimens occurred also in the welding area, and lack of fusion and a large void was observed at the center of the fracture surface. However, the laser-welded specimens showed a ductile failure mode like the as- cast specimens. The results of this study indicated that the tensile strengths of the laser-welded joints were comparable to those of the as-cast joints and superior to those of the soldered joints.

• Korean journal of applied entomology
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• v.57 no.3
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• pp.165-175
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• 2018

Insects are known to live at wide range of temperature, but can not survive when they are exposed to over $40^{\circ}C$ or below supercooling point. The larvae of Helicoverpa assulta have been reared at high ($35^{\circ}C$), low (3 to $10^{\circ}C$), and room temperature ($25^{\circ}C$; control). To identify stress-related genes, the transcriptomes of fat body have been analyzed. Genes such as cuticular proteins, fatty acyl ${\Delta}9$ desaturase and glycerol 3 phosphate dehydrogenase were up-regulated whereas chitin synthase, catalase, and UDP-glycosyltransferase were down-regulated at low temperature. Superoxide dismutase, metallothionein 2, phosphoenolpyruvate carboxykinase and trehalose transporter have been up-regulated at high temperature. In addition, expressions of heat shock protein and glutathione peroxidase were increased at high temperature, but decreased at low temperature. These temperature-specific expressed genes can be available as markers for climate change of insect pests.