• 한국안전학회지
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• 제17권4호
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• pp.45-51
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• 2002

In this study, the fracture characteristics of carbonized silicon grinding wheels were examined with tensile, compression, impact and bending test. The experiment was performed for the various grinding wheels with grain size #46, #80, and grade H, L, P, and one vitrified bond and one structure No.7. Also the centrifugal fracture rpm of carbonized silicon grinding wheels were measured and compared with the calculated values for the various wheel diameters and thicknesses. The results showed that the fracture tensile strength was $1.5~2.0Kg_f/mm^2$, and it was increased by decreasing grain size and increasing grade. The fracture compression loads were $1,600~3,000Kg_f$, and the inner stress was higher than outer's. And the absorption energy of impact test was 3.3~4.7 J, and it was increased by decreasing grain size but it was not effected by grade. The fracture bending stress was $0.1~0.2Kg_f/mm^2$, and it was increased by decreasing grain size and increasing grade. The centrifugal fracture rpm of carbonized silicon grinding wheel was about 8,500~12,000 and agreed well with the calculated value, and it was increased by decreasing diameter. However, it was almost constant for the reduction of wheel thickness.

• 지역사회간호학회지
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• 제26권2호
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• pp.119-127
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• 2015

Purpose: This study is attempted to figure out the characteristics of sexual abuse victimization in low- and high-grade elementary school children and furthermore to help develop appropriate preventive educational programs against sexual abuse by grade. Methods: Data were collected from 156 sexual abuse victims who were elementary school children and visited the Child Sexual Abuse Response Center in D City during the period from 2010 to 2012. Differences in general and victimization-related characteristics between low and high graders and the correlations among the characteristics were analyzed. Results: The results showed statistically significant difference between low and high graders in two variables: offender-victim relationship, and the type of sexual abuse. Offender-victim relationship was in a significant correlation with the duration of victimization (r=.576, p<.001), frequency of abuse (r=.546, p<.001), location (r=-.479, p<.001), and time (r=.435, p<.001). The type of sexual abuse was in a significant correlation with frequency (r=.175, p=.029) and time (r=.261, p=.001). Conclusion: Appropriate educational programs should be developed for preventing sexual assaults in consideration of difference in victimization-related characteristics between low and high graders. In addition, such programs should be applied fittingly to the learners'grade, gender, and cognitive level.

• 보건교육건강증진학회지
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• 제29권5호
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• pp.115-123
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• 2012

Objectives: Students' life changes substantially as grade increases. It implies that risk factors that trigger students' smoking may not be consistent across grades. Most previous studies on student smoking have considered grade simply a control variable. This study examines which and to what extent risk factors are differently associated with smoking initiation according to grade level among high school students in Korea. Methods: Data from the Korean Youth Risk Behavior Web-based Survey (KYRBWS) conducted by the Korea Centers for Disease Control and Prevention (KCDC) in 2007 and 2008 were analyzed in this study. Results: Among boys, school location, school type and pocket money etc. significantly influence smoking initiation in the first grade than in any other grades, but the strength of the association decreased as grade increases except academic performance. Among girls, most independent variables were associated with smoking initiation in the second grade except school location, pocket money per week and academic performance. Conclusions: Our results suggested that the variables related smoking initiation in Korean high school students were notably different by grade and gender. These findings can serve as the basis of policy recommendations with regard to school efforts to prevent student smoking.

• 아동학회지
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• 제26권5호
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• pp.281-295
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• 2005

The study investigated cognitive and creative characteristics related to creative problem solving of intellectually gifted and average children. Fourth and 6th graders from elementary schools in I and B cities and gifted classes in K and I cities were administered the KEDI group IQ test and categorized into gifted(above IQ 125) and average(IQ 90-109) groups. A total of 371 children were selected through this procedure and were tested on formal operational tasks, general metacognitive knowledge, creativity characteristics scales, and creative problem solving tasks. Gifted children were superior to average children on all cognitive and creativity characteristics. For the gifted, grade and metacognition were significant predictors of creative problem solving in the verbal area, and all cognitive and creativity characteristics were significant predictors in the math area. For the average children, grade and metacognition were significant predictors of creative problem solving in the verbal area, and only grade was a significant predictor in the math area.

• 한국콘텐츠학회논문지
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• 제17권10호
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• pp.307-321
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• 2017

본 연구는 중 고등학교 학생 2,260명을 대상으로 Big 5 성격요인에 따른 청소년 성격특성에 발달적 변화가 있는지 알아보고자 한다. 성별과 학년에 따라 성격 5요인의 발달적 변화에 차이를 보이는지 확인하였고, 더불어 신경증 하위요인을 추가적으로 분석함으로써 청소년기 문제행동 시기와 특성을 확인 하였다. 분석에는 일원배치변량분석(One-way ANOVA)을 사용하였으며 유의미한 차이가 난 경우 사후검증을 실시하였다. 연구 결과를 요약하면 다음과 같다. 첫째, 청소년의 성격 5요인 특성이 성별에 따라 차이가 있는 것으로 나타났다. 개방성, 성실성, 외향성은 여자가 남자보다 높게 나타났고, 신경증은 남자가 여자보다 높게 나타났다. 둘째, 청소년의 성격 5요인 특성 모두에서 학년에 따라 차이가 있는 것으로 나타났다. 셋째, 청소년기 성격특성에 대한 성별에 따른 학년별 발달적 경향성에서도 성별 간 다른 양상을 보이는 것으로 나타났다. 특히 성별과 학년에 따른 분석에서 남자는 중등 2학년, 여자는 고등 3학년에서 성격특성이 두드러질 것으로 나타났다. 그리고 신경증과 관련된 외현화 행동문제는 중등 1 2학년에서 내현화 행동문제는 고등 3학년에서 주로 발현될 것으로 나타났다. 따라서 본 연구에서는 현재 우리나라 청소년 성격특성의 발달적 변화를 확인할 수 있었으며, 또한 성별과 학년에 따라 상이한 정신건강문제가 발현 될 수 있는 것으로 나타났다.

• 한국응급구조학회지
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• 제14권2호
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• pp.41-55
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• 2010

Objective : This study is designed to present the direction and the necessity of education on the biomedical ethics the establish desirable ethical view of paramedic students by understanding on the consciousness of students of department of emergency medical technology on biomedical ethics on euthanasia. Method : Data were collected from on 335 students of department of emergency medical technology in 4-year-college located in districts of Chungcheong-do, from March 4 to April 22, 2010. The questionnaire consisted of total 29 items, i.e., 11 items of general characteristics, 11 items of characteristics related to biomedical ethics and 7 items of consciousness on euthanasia. Result : In general characteristics, the first grade showed the most dense distribution of 37.3%, the second grade was 20.0%, the third grade was 20.9% and the fourth grade was 21.8%. In the consciousness of biomedical ethics on euthanasia, the third and the fourth grades showed a higher ratio(${\chi}^2$ = 136.327, p= .000), in comparison with the first and the second grades, the higher year they were, the higher degree of consciousness they had. The consciousness on each item of euthanasia showed significant differences in grade (F = 8.203, p= .000), experience of clinical practice or none (t = 3.731, p= .000), experience of biomedical ethics education or none (t = 1.997, p = .047) and degree of consciousness on DNR (F = 8.240, p = .000) regarding 'CPR shall not be required in any cases if a patient wants DNR', in experience of biomedical ethics education or none (t = 2.452, p= .015) and degree of consciousness on DNR (F = 2.725, p = .044) regarding if a patient refuses all treatments, the patient's opinion shall be respected', and in degree of consciousness on DNR (F = 2.858, p = . 037) regarding 'after determination of DNR, if the family wants a positive treatment, it shall follow the family's request'. Conclusion : It seemed that the differences in consciousness according to grade and experience of clinical practice were influenced by experiences to treat patients in personally. Moreover, it showed that the higher grade they are, the more experience of education they have, the experiences of education had influences on the consciousness. Development of educational programs is required in order to supply accurate knowledge on biomedical ethics for euthanasia to lower-grade students the to let them establish ethical views properly, and in order to correct wrong knowledge and to establish ethical views while supplying knowledge on biomedical ethics for euthanasia to higher-grade students.

• The Journal of Advanced Prosthodontics
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• 제8권5호
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• pp.388-395
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• 2016

PURPOSE. The purpose of this study was to evaluate the resistance to deformation under static overloading by measuring yield and fracture strength, and to analyze the failure characteristics of implant assemblies made of different titanium grades and connections. MATERIALS AND METHODS. Six groups of implant assemblies were fabricated according to ISO 14801 (n=10). These consisted of the combinations of 3 platform connections (external, internal, and morse tapered) and 2 materials (titanium grade 2 and titanium grade 4). Yield strength and fracture strength were evaluated with a computer-controlled Universal Testing Machine, and failed implant assemblies were classified and analyzed by optical microscopy. The data were analyzed using the One-way analysis of variance (ANOVA) and Student's t-test with the level of significance at P=.05. RESULTS. The group $IT4_S$ had the significantly highest values and group IT2 the lowest, for both yield strength and fracture strength. Groups $IT4_N$ and ET4 had similar yield and fracture strengths despite having different connection designs. Group MT2 and group IT2 had significant differences in yield and fracture strength although they were made by the same material as titanium grade 2. The implant system of the similar fixture-abutment interfaces and the same materials showed the similar characteristics of deformation. CONCLUSION. A longer internal connection and titanium grade 4 of the implant system is advantageous for static overloading condition. However, it is not only the connection design that affects the stability. The strength of the titanium grade as material is also important since it affects the implant stability. When using the implant system made of titanium grade 2, a larger diameter fixture should be selected in order to provide enough strength to withstand overloading.

• Journal of Trauma and Injury
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• 제30권3호
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• pp.91-97
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• 2017

Purpose: Purpose: The prognostic factors of non-operative management (NOM) in high-grade spleen injuries have been extensively studied, but factors that would help treatment decisions are lacking. We compared the characteristics of the patients to identify the factors affecting treatment choices. Methods: This is a review of 207 blunt spleen injury patients from January 2004 to December 2013. We compared clinical features and mortality between surgery and NOM, and used multivariate regression analysis to find the factor most strongly associated with prognosis. Results: Of the 207 patients, 107 had high-grade spleen injury patents (grade III or above). Of these, 42 patients underwent surgery and 65 patients underwent NOM. The mortality was 7% following surgery, 3% with NOM. The amount of packed red blood cells transfused in the first 24 hours and spleen injury grade were associated with management type, and mortality was highly associated with activated partial thromboplastin time (aPTT) and spleen injury grade. Conclusions: The grade of spleen injury was associated with management and mortality, so correctly assessing the spleen injury grade is important.

• 한국학교ㆍ지역보건교육학회지
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• 제8권1호
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• pp.55-68
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• 2007

Objectives: This study was conducted to describe child perceived health knowledge, health education needs, and health behaviors by grade in a representative general characteristic and examined their associations for students' better health behaviors. Methods: The survey participants were 410 fourth to sixth grade students in two elementary schools in Seoul, Korea. A total of 12 classes in two elementary schools were randomly selected and all students of the selected classes participated in the self-administered survey. The questionnaire contained the items of perceived health knowledge, health education needs(health topics which they want to know more), health behavior, and general characteristics. Results: Perceived health knowledge, health education needs, and health behaviors were, generally, better in the $4^{th}$ grade students than $5^{th}$ or $6^{th}$ grade students. That is, higher grade students had lower perceived health knowledge, lower health education needs, and lower health behavior status. Specifically, there was significant grade differences in 'significance of publichealth,' 'nutritionandhealthyeating,' 'desirablehealthhabits,' 'humansex,' 'physical development in childhood,' 'stress management & drugcontrol,' and 'injury prevention.' Correlations between perceived health knowledge and health behavior were low or medium in all grades. However, correlations between perceived health education needs and health were significant in the $4^{th}$ grade students but not significant in the $5^{th}$ and $6^{th}$ grade students. Conclusions: There was significant grade difference of the relationship between health knowledge, health education needs, and health behaviors among children. In general, the lower the grade the better the health knowledge, educational needs, and health behavior. Health education needs were more significant by grade than perceived health knowledge and health behaviors.

• 한국식품영양과학회지
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• 제30권6호
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• pp.1152-1157
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• 2001

도축 후 24시간 냉장한 상등급(B2 등급)과 등외등급(D 등급) 쇠고기 지육에서 등심부위를 분할하여 두 쪽으로 나누어 한 쪽은 랩으로 싸서 1일간 냉장하고, 다른 한 쪽은 500g씩 자르고 진공포장하여 30일간 냉장하여 전자는 신선육, 후자는 냉장육이라 하였다. 상등급육과등외등급육의 기호특성을 비교하고 등외등급육의 냉장효과를 알아보기 위하여 신선육과 냉장육의 색도, 연도, ATP 관련물질, 지방산 조성 및 관능평가에 대한 실험을 하였다. 신선육의 경우 상등급육이 등외등급육에 비하여 pH. 젖산함량, 미오글로빈 함량이 낮고 표면색이 우수하였다. 상등급육은 경도와 저작성이 낮으면서 근원섬유 소편화도가 높아 연한 현상을 보였다. 상등급육은 포화지방산 함량이 낮고 단일 불포화지방산에 대한 포화지방산의 비율(MUFA/SFA)과 ATP 함량이 높고, 생육향이 우수하였다. 상등급육은 가열감량 및 가열단축도가 낮은 반면 가열육의 기호성이 현저히 우수하였다. 등외등급육은 상등급육에 비해서 경도, 저작성, 근원섬유 소편화도 및 MUFA/SFA에 대한 냉장효과가 크게 나타났다. 그러나 냉장육의 연도, 가열육 향 그리고 기호성이 등외등급육에 비해 상등급육이 현저히 우수하였다.