• Proceedings of the Korea Society of Costume Conference
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• 2004.10a
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• pp.128-129
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• 2004

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.453-454
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• 2012

• Journal of Biosystems Engineering
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• v.42 no.3
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• pp.163-169
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• 2017

Purpose: This study was performed to evaluate the feasibility of using an infrared thermography technique for phenotype analysis of pepper seedlings exposed to a low-temperature environment. Methods: We employed an active thermography technique to evaluate the thermal response of pepper seedlings exposed to low-temperature stress. The temperatures of pepper leaves grown in low-temperature conditions ($5^{\circ}C$, relative humidity [RH] 50%) for four periods (6, 12, 24, and 48 h) were measured in the experimental setting ($23^{\circ}C$, RH 70%) as soon as pepper seedling samples were taken out from the low-temperature environment. We also assessed the visible images of pepper seedling samples that were exposed to low-temperature stress to estimate appearance changes. Results: The greatest appearance change was observed for the low-temperature stressed pepper seedlings that were exposed for 12 h, and the temperature from these pepper seedling leaves was the highest among all samples. In addition, the thermal image of low-temperature stressed pepper seedlings for 6 h exhibited the lowest temperature. Conclusions: We demonstrated that the leaf withering owing to the water deficiency that occurred under low-temperature conditions could induce an increase in temperature in plant leaves using the infrared thermography technique. These results suggested that the time-resolved and averaged thermal signals or temperatures of plants could be significantly associated with the physiological or biochemical characteristics of plants exposed to low-temperature stress.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.1
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• pp.65-67
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• 2003

Flounder (Paralichthys olivaceus) fish goes through metamorphosis in the larvae phase. In this phase, it secretes much thyroid hormone to control metamorphosis. Sharp change in the environment and nutrition deficiency may cause stress in the metamorphosis phase. It leads to interfering with the development of thyroid hormone and finally inhibits the normal growth of larvae. In this study, the correlation between the change in thyroid hormones and the albinism appearance was examined by growing them with low temperature ($13^{\circ}C$) stress over the premetamorphosis stages (stage $D\~F$) of flounder metamorphosis. Albinism rate was $15\%$ in the low temperature group and $25\%$ in the control goup. $T_{4}\;and\;T_{3}$ of the control group tended to increase from stage F as larvae grew. $T_{4}$ increased 2 times compared to the control group as 72 ng/g at stage H, the increasing phae of water temperature, in the low temperature group. $T_{3}$ increased 8 times compared to the control group as 2.9 ng/g at stage E, the decreasing phase of water temperature. Therefore, it is judged that the albinism appearance of flouner is caused from the sharp increase in $T_{3}$ by the inappropriate secretion of thyroid hormone.

• Journal of Haehwa Medicine
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• v.8 no.1
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• pp.865-878
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• 1999

With advances in neonatal medicine, smaller and sicker infants are surviving premature birth. As these tiny patients battle for their lives, their parents also struggle with psychological consequences of an unexpected role. The birth of a sick infants has long been documented as stressful events for the parents. High stress levels may alter parents' interaction with their baby and impair their communication with health professionals, which can in turn affect parents' participation in care planning and decision making. Nursing interventions aimed at reducing the parental stress and anxiety levels during this crisis may have a positive impact on their ability to form an attatchment to their baby and make prudent decisions about his care. The planning of such interventions would be inhanced if the contributions of various factors to increased parental stress levels were identified. This descriptive study was conducted to understand the contents and degree of parental stress in the NICU during their premature's hospitalization, and to give a baseline data in developing nursing intervention program. Subjects were the 60 mother of hospitalized newborn in NICU of 2 University Hospital in Taejon City from April 1st, 1999 to June 30th, 1999, who agreed to take part in this study. The instrument used in this study were Parental Stressor Scales:NICU(PSS:NICU) developed by Miles et al.. and validated by 3 NICU practitioners and 3 child health nursing faculties. The questionnaire has 4 dimensions and 45 items; sight and sounds of NICU(5 items), babies' appearance and behavior nursing intervention(19 items), parental role alteration and relationship with their baby(10 items), health team communication(11 items). The questionnaire asks parents to rate each item on a five-point Likert type scale that ranges from "not stressful" (1) to "extremely stressfu1"(5). Total scores representing overall stress from the NICU environment are calculated by summing response to each item. A high score indicates high stress. A subscale score is calculated by summing the responses to each item in the subscale. Cronbach's ${\alpha}$ coefficients were .93. The data was analyzed as average, Frequency, Standard deviation, t-test, ANOVA, Pearson correlation coefficient by use of SPSS/PC+. The results of this study is summarized as follows ; 1. The total perceived stress level score of mothers of premature baby was slightly high($3.66{\pm}1.1$). The highest scored dimension was 'relationship with their baby and parental role change'($4.21{\pm}0.9$), and next were 'appearance and behavior of the baby'($3.92{\pm}1.1$), 'communication with health team'($3.32{\pm}1.3$), 'sight and sounds of NICU'($3.30{\pm}1.1$). 2. There were statistically significant correlation noted ; mother's perceived severity of the baby's condition(F=8.0012, P= .0125) and baby's gestational age(r = -.4724, P = .0500). In summary, information about physical environment of NICU, the mother's perceived severity of premature baby's state, maternal role change related variables and the knowledge of characteristics of premature baby must be included in nursing intervention program of mother's of premature baby in reducing the parental stress and anxiety level. It is suggested that each NICU needs to develop a nurse managed supportive care program for parents of premature baby. Also, it is suggested that there need to investigate the coping mechanism of mother of premature baby.

• Journal of dental hygiene science
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• v.16 no.1
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• pp.45-52
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• 2016

The purpose of this study was to examine the impact of the self- perceived stress of high school students on their oral health care and the relationship between stress and oral health care. The subjects in this study were the students in four different high schools located in Chungcheongnam-do, on whom a self-administered survey was conducted. The answer sheets from 939 respondents were analyzed by PASW Statistics ver.18.0 for Windows. The girls were more stressed than the boys about their studies, appearance and material resource, and the sophomores felt more stress about their home and studies. The group whose academic achievement was good in the past semester had the lowest stress about home and material resource, and the group whose economic standard was higher were less stressed about appearance and material resource. As a result of comparing their oral health care by general characteristics, the groups who were sophomores and whose academic achievement was good in the past semester were most excellent in that regard, and the students whose economic standard was higher and whose average weekly allowances were larger took better care of their oral health. Concerning the influential factors for oral health care, stress about peer relationship was positively related, and stress about material resource was negatively related. Given the findings of the study, the development of oral health care programs that include how to relieve stress is required, and more intensive education is necessary as well. Besides, education for school personnel in charge of student health management and the development of related manuals are both required.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.6
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• pp.101-107
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• 2003

Since stainless steel sheets have good mechanical properties, weldability, appearance and corrosion resistance, they are commonly used as one of the structural materials of the railroad cars or the commercial vehicles which are manufactured by the spat welding. Among the many kinds of spot welded lap joints, it can be found that multi-lap joints are employed in their body structure. But, fatigue strength of these joints is lower than that of base metal due to high stress concentration at the nugget edge of spot weld and is considerably influenced by welding conditions as well as the mechanical and geometrical factors. Thus, it is necessary to establish a reasonable and systematic design criterion for the long life design of the spot-welded body structures. In this paper, the stress distribution and deformation around the spot-welded multi-lap joints subjected to tensile shear load was numerically analyzed. Also, the $\Delta$P-Nf curve was obtained by fatigue tests. Using these results, $\Delta$P-Nf curves were rearranged in to the ${\Delta}{\sigma}$-Nf relation with the maximum stress at nugget edge of spot weld.

• Journal of Korean society of Dental Hygiene
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• v.14 no.4
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• pp.471-478
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• 2014

Objectives : The purpose of the study was to investigate the correlation between self-esteem and stress after orthodontic treatment in the adolescents. Methods : A self-reported questionnaires was filled out by 347 high school students from September 23 to October 11, 2013. Data were analyzed using descriptive statistics, $x^2$-test, Fisher's exact test, t-test and Pearson correlation coefficient by SPSS 20.0 program. Results : Among 347 students, 25.4% of the students experienced orthodontic treatment. Significant differences existed in gender, satisfaction with dental appearance, uncomfortable level of biting and chewing, recognition of orthodontic treatment in orthodontic treatment group and non-treatment group. Self esteem was lower in orthodontic treatment group and stress was higher in orthodontic group. Self esteem had a negative correlation with stress. Conclusions : There existed the close relationship between self-esteem, stress, and dental malocclusion in the adolescents.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.378-383
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• 2002

In previous study, the decrease and recovery of total stiffness in welded structure was discussed on the basis of experimental examination through tensile loading and unloading test of welded specimen. The recovery of structure stiffness was caused by the release of welding residual stress through mechanical loading. In this study, analysis model that is indispensable for the effective application of MSR method was established on the basis of test and measurement result. Thermal elasto-plastic analysis for welding process was performed by non-coupled analysis. Analysis results of welding process were transfer to elasto-plastic model for tensile loading & unloading by restart technique. In elasto-plastic analysis model for mechanical loading & unloading, hardening appearance of weld metal was considered by rezoning technique and tying technique was used for JIG condition of test machine.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.191-192
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• 2006

The deformation under radial pressure of rectangular dies for metal powder compaction has been investigated by FEM. The explored variables have been: aspect ratio of die profile, ratio between diagonal of the profile and die height, insert and ring thickness, radius at die corners, interference, different insert materials, i. e. conventional HSS, HSS from powders, cemented carbide (10% Co). The analyses have ascertained the unwanted appearance of tensile normal stress on brittle materials, also "at rest", and even some dramatic changes of stress patterns as the die height increases with respect to the rectangular profile dimensions. Different materials behave differently, mainly due to difference of thermal expansion coefficients. Profile changes occur when the dies are heated up to the temperature required for warm compaction. The deformation patterns depend on compaction temperature and thermal expansion coefficients.