• Title/Summary/Keyword: 검사 결과

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Quantitative Defects Detection in Wind Turbine Blade Using Optical Infrared Thermography (광 적외선열화상을 이용한 풍력 블레이드의 결함 크기 정량화 연구)

  • Kwon, Koo-Ahn;Choi, Man-Yong;Park, Hee-Sang;Park, Jeong-Hak;Huh, Yong-Hak;Choi, Won Jae
    • Journal of the Korean Society for Nondestructive Testing
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    • v.35 no.1
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    • pp.25-30
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    • 2015
  • A wind turbine blade is an important component in wind-power generation, and is generally exposed to harsh environmental conditions. Ultrasonic inspection is mainly used to inspect such blades, but it has been difficult to quantify defect sizes in complicated composite structures. Recently, active infrared thermography has been widely studied for inspecting composite structures, in which thermal energy is applied to an object, and an infrared camera detects the energy emitted from it. In this paper, a calibration method for active optical lock-in thermography is proposed to quantify the size. Inclusion, debonding and wrinkle defects, created in a wind blade for 100 kW wind power generation, were all successfully detected using this method. In particular, a ${\phi}50.0mm$ debonding defect was sized with 98.0% accuracy.

The Effects of Portfolio Assessment on Elementary School Students' Science Knowledge, Inquiry Ability and Science Attitudes (자연과 수업에 증거집(포트폴리오) 평가의 적용이 초등학교 학생들의 과학 지식, 탐구능력 및 태도에 미치는 영향)

  • Kim, Hye-Jeong;Kim, Chan-Jong
    • Journal of The Korean Association For Science Education
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    • v.19 no.1
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    • pp.19-28
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    • 1999
  • The major purposes of this study are to examine the effects of portfolio assessment on elementary school student's science knowledge, inquiry ability, science attitudes and to investigate students' perceptions on portfolio assessment. Control group consists of 45 fourth-graders at M-Elementary school located at Miwon, Chongwon-gun, Chung-buk and experimental group 36 fourth-graders of G-Elementary school located in Daejeon-si. The inventories of scientific knowledge I, inquiry ability, and science attitudes were administered to both groups as a pre-test. The experimental group was given portfolio assessment instruction and control group traditional instruction for about six weeks. Inventories about scientific knowledge 2, inquiry ability, and science attitudes were administered to both groups as a post-test. A questionnaire on the perception on portfolio assessment was given to experimental group after the treatment. The results were statistically analyzed with SPSS. Control group showed higher score on scientific knowledge than that of experimental group (p<0.5). No statistically meaningful difference was identified in inquiry ability and scientific attitude. More in-depth analysis revealed that scientific attitudes were improved statistically meaningfully by portfolio assessment. The students' perceptions on portfolio assessment is very positive. Students have positive responses on interests in portfolio assessment, feelings of involvement in learning, self-regulated learning, higher levels of thinking, intentions of participation in portfolio assessment.

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Comparisons of Cognitive Functions between Urban and Rural Dwelling Older Adults: A Preliminary Study (도시와 농촌거주 노인의 인지기능 비교: 예비연구)

  • Kim, Jung Wan;Kang, Yeonwook;Yoon, Ji Hye
    • Journal of Digital Convergence
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    • v.15 no.4
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    • pp.469-476
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    • 2017
  • Mini-Mental State Examination (MMSE) and naming tests have been used clinically as screening and diagnostic tools for mild cognitive impairment and dementia. Researches in other countries have reported that residential areas would affect one's cognitive abilities. In Korean, however, there was no systematic studies on geographical influences to cognitive ability among a sample of urban/rural residents. The aim of this study was to investigate the effect of urban/rural locality of residence on cognitive tests in normal elderly Korean. Residents aged 65 years and older (N=108) were administered the K-MMSE, confrontation/generative naming tests, and medical/socio-demographic interview. When comparing the total number of correct responses between urban residents and rural residents, the performances of rural group were significantly worse than those of the urban group in K-MMSE. Based on the results, our finding suggests that a factor of residential locality should be considered to examine the function and explain the cognitive decline in rural community-dwelling elders.

Non-Destructive Testing of Damaged Thermoplastic Pipes Electrofusion Joints Using Phased Array Ultrasonic (위상배열초음파를 이용한 손상된 열가소성 플라스틱배관 전기융착부 비파괴검사)

  • Kil, Seong-Hee;Kim, Byung-Duk;Kwon, Jeong-Rock;Yoon, Kee-Bong
    • Journal of the Korean Institute of Gas
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    • v.17 no.5
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    • pp.64-68
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    • 2013
  • Non destructive testing(NDT) methods of electrofusion(EF) joints of thermoplastics pipes are required for fusion joint safety and for the long term reliability of a pipe system. Electrofusion joints, which are joined at the proper fusion process and procedures, may encounter defects due to the difference of ovality between pipes and coupling, improper fusion process or porosity result from electrofusion joining. These defects can cause the failure of pipeline and by extension, they can be caused the limit to expand the use of plastics pipes. This paper studies inspection results using ultrasonic imaging method for damaged polyethylene electrofusion joints. Gas was leaking from 250mm diameter polyethylene electrofusion joints at February 2004 which was electrofused at December 1994 and operation pressure was 2.45kPa. First, surface inspection was conducted and then in order to find the types of defects examination using ultrasonic imaging method was performed. Lack of fusion and inappropriate inserting for polyethylene pipes into electrofusion coupling were found and causes of the gas leak were judged that misalignment and insert defect. Cutting inspection was performed and each inspection results were compared to. Results of ultrasonic imaging method and cutting inspection were the same.

Usefulness of Korean Infant Developmental Screening Test in Premature Infants (미숙아에서 한국형 영유아 발달검사의 유용성)

  • Shin, Dong Han;Lee, Hee Sun;Lee, Jee Yeon;Choi, Byung Min;Eun, Baik-Lin;Hong, Young Sook;Lee, Joo Won
    • Clinical and Experimental Pediatrics
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    • v.48 no.12
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    • pp.1337-1341
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    • 2005
  • Purpose : This study aimed to evaluate the usefulness of Korean Infant Development Screening Test in predicting delayed development in premature infants. Methods : A total of 74 children with histories of prematurity, who visited the pediatric neurology clinic of Korean University Ansan Hospital from August, 2002 to July, 2004, were examined, using the Korean Infant Development Screening Test. They were divided into two groups; a normal group and a patient(neurologically compromised) group. Results : At 7 months of conceptional age, the normal and patient groups differed significantly in the fine motor, cognitive-adaptive sections. At 12 months of conceptional age both group, differed significantly in the gross motor, fine motor, personal-social, language and cognitive-adaptive sections. At 18-24 months, the group, differed significantly in gross motor, fine motor, personal-social, language and cognitive-adaptive sections. Conclusion : The Korean Developmental Screening Test was useful in predicting developmental delay in premature infants.

The Effect of Mentoring Participation on Science Teachers' General Teaching and Science Teaching Efficacies (멘토링 참여 경험이 과학교사의 일반교수효능감과 과학교수효능감에 미치는 영향)

  • Kang, Kyunghee
    • Journal of The Korean Association For Science Education
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    • v.37 no.6
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    • pp.951-960
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    • 2017
  • The purpose of this study is to examine the effects of mentoring in enhancing the professionalism of low-experience science teachers on their general teaching and science teaching efficacies. The mentoring for low-experience science teachers was conducted on 24 science teachers with less than three years of experience over a nine-month period between April and December, 2016. The questionnaires developed by advanced researches were modified and used to test the teachers' general teaching and science teaching efficacies. As the result of a pre-test, the mean science teaching efficacy score was 3.02 points. In particular, the mean science teaching self-efficacy score was 2.86 points and the mean science teaching outcome expectancy score was higher at 3.17 points. In the domain of science teaching outcome expectancy, the mean for female teachers was higher than that of male teachers, and the mean for middle school teachers was higher than that of high school teachers in every domain. However, this result is not statistically significant. The results of a post-test showed that the mean science teaching efficacy score of mentee teachers increased to 3.08 points over the pre-test. In particular, the mean science teaching self-efficacy score was 3.11 points and the mean science teaching outcome expectancy score was 3.04 points in the post-test. This presents that the mentoring training conducted was effective in improving the science teaching efficacy of mentee teachers.

Influence of stress and pure tone audiometry on noise-exposed dental laboratory technicians by dental instrument (치과기공 소음 노출이 치기공과 학생의 스트레스와 순음청력에 미치는 영향)

  • Yon, Jung-Min;Lee, Ju-Hee;Kim, Dae-Hyun;Lee, Og-Kyoung
    • Journal of Digital Convergence
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    • v.14 no.4
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    • pp.363-370
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    • 2016
  • Noise is unwanted sound that is the reason of the stress and hearing loss. The current study attempted to estimate whether the noise of dental laboratory affected stress and pure tone audiometry (PTA) of dental laboratory technicians (DLTs) using heart rate variability, air and bone conduction audiometry. The age, heights, and weights of DLTs were resembled control. Standard deviation of normal to normal interval such as stress resistance and normalized HF of DLTs were significantly decreased, but heart rates, normalized LF, and LF/HF ratio of DLTs were significantly increased compared with control. In air conduction audiometry of DLTs, significant increments of thresholds encountered in 125, 250, 500, 1000, 2000, 3000, 4000, and 6000 Hz in the right ears and 125, 250, 500, 1000, and 2000 Hz in the left ears. Thresholds of bone conduction audiometry in both ears were significantly increased in 250, 500, 1000, 2000, and 4000 Hz. The findings in this study provide that stress and hearing loss observed in noise-exposed DLTs at dental laboratory. Therefore, proper safety precautions should be carried out at dental laboratory.

재료 내부 결함 검출을 위한 첨단 테라헤르츠 비파괴 검사법 소개

  • Kim, Hak-Seong
    • Journal of the KSME
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    • v.57 no.5
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    • pp.32-37
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    • 2017
  • 최근 들어 안전한 사회 구축을 위한 기계 구조물 신뢰성에 관한 관심이 커지면서 다양한 비파괴 검사법에 대한 기술 수요가 급증하고 있다. 이 글에서는 각종 재료의 불량 검출을 위한 테라헤르츠 비파괴 검사법과 그 응용 사례들을 간단히 소개한다.

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Validation of Korean Diagnostic Scale of Multiple Intelligence (한국형 다중지능 진단도구의 타당화)

  • Moon, Yong-Lin;Yu, Gyeong-Jae
    • (The) Korean Journal of Educational Psychology
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    • v.23 no.3
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    • pp.645-663
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    • 2009
  • The purpose of this study is to develop and verify a Korean Diagnostic Scale of Multiple Intelligence(MI), which will be an alternative test to avoid problems with former Shearer's MI test and to adopt H. Gardner's suggestions to develop MI assessment. The test is developed 5 types; kindergartner, elementary lower grader, elementary upper grader, middle schooler, high schooler test. A form of test is diversified with 3 types; multiple-choice items for accomplishment, true or false items for ability, and self-reported items with likert scale for interest and ability. According to H. Gardner's suggestions, we have tried to reanalyze key component of MI, analyze an overlapping or hierarchical relationship between intelligences, develop intelligences-fair items, diversify form of item. We have developed a final standardized test through a primary, secondary preliminary-test analysis, and sampled 5,585 students by age, gender, and regional groups. As a result of this sampling test, we can get a norm score and compare individuals with other's score relatively. To verify this test, we analyzed behavior observation, mean, standard deviation, a percentage of correct answers, reliability of each test type, correlation between intelligence scales, Kruskal-Wallis test of mean rank of career choice by intelligences. As a result of correlation analysis between sub-intelligence scales, we can conclude that this MI test is satisfied with intelligence independent assumption. Besides, as non-parametric statistics test(Kruskal-Wallis) of career choice by intelligences, we can identify that MI is related with domain of career choice. This test is not a linguistic and logical-mathematical biased test but a intelligences-fair test. It makes us compare individual's potential with a norm score. Besides, it could be useful as a means of educational prescription or counsel in comparison with ability, interest, and accomplishment of individual. But this test is limited to do factor or correlation analysis between types of sub-test, because items are minimized for a time-constraint and a heavy burden of test receiver. But if it could be tested with increased items by two sessions, further research could be expected to get over this constraints and do a further validation analysis.