• Proceedings of the Safety Management and Science Conference
• /
• 2010.11a
• /
• pp.639-649
• /
• 2010

신뢰성 기술은 제품이 고장 없이 일정기간 사용할 수 있게 하는 기술로 시장점유율과 고객만족을 높이는 효과적이고 전략적인 필수 요소이다. 검사시점의 적합성에 대한 평가가 아닌 제품 및 시스템의 설계에서부터 폐기까지의 제품수명주기에 대한 신뢰성 평가를 다루는 제품의 신뢰성인증과 신뢰성경영시스템 인증 확보가 시급한 과제이다. 이를 위한 제품 수명의 평균과 분산을 효과적으로 관리할 수 있는 신뢰성 식스시그마 기술개발과 확보가 중요 현안과제이다. 정규분포를 가정한 대부분의 품질경영시스템에서의 식스시그마 접근법은 비정규 분포를 따르는 신뢰성특성과 실험계획기법 등을 고려해야 하는 신뢰성 식스시그마에서의 적용의 한계가 많다. 본 연구에서는 품질혁신 방법론인 식스시그마 기법을 토대로 신뢰성경영시스템에서 맞는 식스시그마 구축의 방향성을 제시하고자 한다.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 2011.11a
• /
• pp.364-368
• /
• 2011

최근 급속히 발전하고 있는 과학기술과 산업발달에 따라 화학물질, 위험물의 사용, 저장 및 운송물이 날로 증가하고 있다. 이러한 물질들은 우리의 일상생활과 인류문화 발전에 크게 기여하고 있지만 인화성, 폭발성 등의 잠재위험성을 가지고 있다. 세계 각국은 물질의 분류와 표시가 달라 국제무역에서 많은 사고가 증가하고 있는 실정이다. 이 연구의 목적은 자기반응성물질의 화재 폭발 위험성을 평가하고, 국제적인 시험방법과 국내 시험방법으로 시험하여 연관성 및 상관관계를 알아보고 선진화된 시험방법을 국내실정에 적합하게 제시하는데 있다.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.20 no.6
• /
• pp.931-946
• /
• 2018

In line with the increased usability of utility pipe conduits in urban areas, construction and R&D activities of utility tunnel, incorporated with the shield TBM method, are actively under way. The utility tunnels are installed through underground excavation, and thus are relatively weak in terms of construction safety. However, hazards associated with the utility tunnel construction have not been properly identified, despite the introduction of a policy to the 'Design for Safety' for the purpose of reducing accident rates in the construction industry. Therefore, in this study, following the derivation of hazards associated with utility tunnel, these hazards were then used as the basis to uncover key safety hazards requiring extensive management in a field, which were then used to conduct a risk assessment having applied the matrix method so that the results can be utilized in risk assessment during the stages of utility tunnel planning, design, and construction, while also serving as a data reference.

• Journal of the Korean Society for Library and Information Science
• /
• v.57 no.3
• /
• pp.249-277
• /
• 2023

The purpose of this study is to explore the potential contribution of citation metrics to improving the search performance of citation index databases. To this end, the study generated ten queries in the field of library and information science and conducted experiments based on the relevance assessment using 3,467 documents retrieved from the Web of Science and 60,734 documents published in 85 SSCI journals in the field of library and information science from 2000 to 2021. The experiments included re-ranking of the top 100 search results using citation metrics and search methods, query expansion experiments using vector space model retrieval systems, and the construction of a citation-based re-ranking system. The results are as follows: 1) Re-ranking using citation metrics differed from Web of Science's performance, acting as independent metrics. 2) Combining query term frequencies and citation counts positively affected performance. 3) Query expansion generally improved performance compared to the vector space model baseline. 4) User-based query expansion outperformed system-based. 5) Combining citation counts with suitability documents affected ranking within top suitability documents.

• Journal of The Korean Association For Science Education
• /
• v.23 no.1
• /
• pp.75-85
• /
• 2003

We have developed of a criterion that would help to select and develop performance assessments in science education. There are six categories of a criterion: Fidelity, satisfaction, content validity, fairness & suitability, reliability & objectivity, and usability. There are the total of 25 sub-categories under the six categories. Five science educators evaluated the validity of the criterion. For reliability of the criterion, Kendall's tau-b was used. Eight science educators and elementary teachers evaluated three performance assessment tasks for the correspondence of the criterion. This study also discuss the implications of this criterion as well.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
• /
• 2002.11a
• /
• pp.255-261
• /
• 2002

본 연구개발에서 개발되어지고 있는 시뮬레이터는 롤러코스터를 모사 대상체로 하였고, 일반적인 Stewart 형식이 아닌 운동 대상체의 운동자유도를 짐발(Gimbal)형으로 재현하고자 하였다. 이를 위해 실시간 스케쥴러와 H/W 입출력 및 통신 드라이버에 대한 개발을 수행하였고, 시뮬레이션에 적합한 정확도와 실시간성을 유지하도록 롤러코스터 상에서 이루어지는 차량운동을 모델링 하였다. 또한 인간감성의 적용을 고려한 짐발형 모션 시스템의 운동 재현을 위해 워시아웃(Washout) 알고리즘을 개발하였다. 특히, 짐발형 모션 시스템의 운동 모사성을 객관적으로 검증하고 탑승자에 대한 시뮬레이터의 영향을 평가하기 위해 감성평가를 실시하였다. 감성평가를 위해 평가지에 의한 주관적 평가 방법과 탑승자의 생리신호를 측정하는 객관적 평가방법을 사용하였으며, 감성평가를 통한 결과치를 이용하여 워시아웃 알고리즘을 개선하였다.

• The Journal of Korean Academy of Prosthodontics
• /
• v.58 no.1
• /
• pp.7-13
• /
• 2020

Purpose: This study was to evaluate marginal and internal discrepancy of 3-unit fixed dental prostheses (FDP) fabricated by subtractive manufacturing and additive manufacturing. Materials and methods: 3-unit bridge abutments without the maxillary left second premolar were prepared (reference model) and the reference model scan data was obtained using an intraoral scanner. 3-unit fixed dental prostheses were fabricated in the following three ways: Milled 3-unit FDP (MIL), digital light processing (DLP) 3D printed 3-unit FDP (D3P), stereolithography apparatus (SLA) 3D printed 3-unit FDP (S3P). To evaluate the marginal/internal discrepancy and precision of the prosthesis, scan data were superimposed by the triple-scan protocol and the combinations calculator, respectively. Quantitative and qualitative analysis was performed using root mean square (RMS) value and color difference map in 3D analysis program (Geomagic control X). Statistical analysis was performed using the Kruskal-Wallis test (α=.05), MannWhitney U test and Bonferroni correction (α=.05/3=.017). Results: The marginal discrepancy of S3P group was superior to MIL and D3P groups, and MIL and D3P groups were similar. The D3P and S3P groups showed better internal discrepancy than the MIL group, and there was no significant difference between the D3P and S3P groups. The precision was excellent in the order of MIL, S3P, and D3P groups. Conclusion: Within the limitation of this study, the 3-unit fixed dental prostheses fabricated by additive manufacturing showed better marginal and internal discrepancy than the those of fabricated by subtractive manufacturing, but the precision was poor.

• Journal of the Korean Geotechnical Society
• /
• v.27 no.8
• /
• pp.5-16
• /
• 2011

The objective of this paper is to assess the potential use of the resilient force of the ground obtained from an accelerometer and to propose a new compaction control process. Several comprehensive field experimental programs were conducted to analyze the correlation of compaction results obtained from an accelerometer and conventional test methods (e.g. the plate load test and field density test). This study focused on comparing the compaction results obtained from an accelerometer with conventional test results statistically. Based on the statistical analysis results, impact and resilient force measured from an accelerometer, mounted on the drum of a roller are very useful factors for continuous compaction control. A new compaction criteria determination process using an accelerometer is also proposed in this study.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.16 no.1
• /
• pp.106-116
• /
• 2005

Summary : This study was designed to identify the difference in temperament, parent-adolescent's goodness of fit and behavioral problems between early-adolescent high risk group which can be divided into subgroups (ADHD-I and ADHD-HI/C) and normal group. Method : Subjects of this study were students of a Boy's Middle School and their parents. ADHD high risk group was determined by using three rating scales of ADHD behavioral symptoms : 1. Korean-ADHD Rating Scale, 2. Abbreviated Conners Parents Rating Scale, 3. Conners-Wells' Adolescent Self-Report Scale. Final research was based on the subjects including 25 people in ADHD-I high risk group, 70 ADHD-HI/C high risk group, 70 in normal group. Revised Dimensions of Temperament (DOTS-R) was used for students to assess their temperament, while DOTS-R : Ethnology for parents to access environmental demands. Goodness of fit between parent and adolescent was figured out by results of the two scales. Korean Youth Self Report (K-YSR) was used to examine behavioral problems. Results : When it comes to temperament of adolescents, ADHD-HI/C high risk group was found to be associated with higher scores on general activity level. In contextual parent demand to adolescent, ADHD-HI/C parents showed higher level of demands in general activity than other groups, and lower expectation of positive mood than ADHD-I parents. In parent-adolescent's goodness/poorness of fit, the research found out that ADHD-I and ADHD-HI/C had lower level of fit on pesitive/negative mood than normal group and indicated that ADHD behavioral symptoms connected with poorness of fit in emotional relationship between adolescents and their parents. In behavioral problems, ADHD-HI/C high risk group had severe externalizing and internalizing problems distinctly. It had more severe in externalizing problems than ADHD-I, while there were no differences in internalizing problems between the two subgroups. Conclusion The two ADHD subgroups in high risk adolescents had differences on temperamental activity level and on goodness of fit about positive mood. In addition, they had different patterns in externalizing/internalizing problems.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.16 no.11
• /
• pp.2544-2549
• /
• 2012

The computer programming education is very important to study the related subjects in computer science, and also in the technology education for the students finding employment. In this paper, we develop the assessment metrics to evaluate and apply the textual and visual programming in the computer education. Also, we analyze the validity for the programming languages and tools for the education and getting job of students, and choose the appropriate programming language/tool for programming education. And, we develop the curriculum for programming education, finally apply and analyze in computer education of university. Especially, we compare and analyze the effectiveness for the text based programming language(JAVA) and visual programming language/environment(LabVIEW) in the area of embedded/mobile/Web programming fields which are necessary in the related industry to the recent trend of IT technology.