• 한국신뢰성학회:학술대회논문집
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• 한국신뢰성학회 2005년도 학술발표대회 논문집
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• pp.109-113
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• 2005

Optimality for block designs have received much attention in the literature. Here we review these criteria and present results showing their A,D and E connection. Also we acquainted with the mathematical methods of designing optimal experiments. In this paper, we will to do work about optimality in experimental designs.

• Transactions on Electrical and Electronic Materials
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• 제2권3호
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• pp.28-32
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• 2001

It was studied in the present work how the thermal cycling performance of LOC (lead on chip) packages depends on the package construct or leadframe materials. First, package body thickness and Au wire diameter were manipulated for the selection of proper package design. Secondly, two different types of leadframe materials (i.e. copper and 52%Fe-48%Ni alloy) were tested to determine the better material for improved reliability margin of plastically encapsulated microelectronic packages. This work shows that manipulating package body thickness was more effective than an increase of Au wire from 23$\mu\textrm{m}$ to 33$\mu\textrm{m}$ for the prevention of wire debonding failure. Further, this work indicates that the LOC packages including the copper leadframes can be more susceptible to thermal cycling reliability degradation due to chip cracking than those including the alloy leadframes.

• 한국산업융합학회 논문집
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• 제23권5호
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• pp.799-807
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• 2020

This paper deals with identification of probabilistic design using reliability based robust optimization in structure design of automatic salt collector. The thickness sizing variables of main structure member in the automatic salt collector were considered the random design variables including the uncertainty of corrosion that would be an inevitable hazardousness in the saltern work environment. The probabilistic constraint functions were selected from the strength performances of the automatic salt collector. The reliability based robust optimum design problem was formulated such that the random design variables were determined by minimizing the weight of the automatic salt collector subject to the probabilistic strength performance constraints evaluating from reliability analysis. Mean value reliability method and adaptive importance sampling method were applied to the reliability evaluation in the reliability based robust optimization. The three sigma level quality was considered robustness in side constraints. The probabilistic optimum design results according to the reliability analysis methods were compared to deterministic optimum design results. The reliability based robust optimization using the mean value reliability method showed the most rational results for the probabilistic optimum structure design of the automatic salt collector.

• 한국조리학회지
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• 제17권4호
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• pp.219-237
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• 2011

본 연구의 목적은 국내 외식업계의 비정규직 직원을 대상으로 핵심자기평가, 일-가족 지원, 직장만족 그리고 이직의도의 관계를 분석함으로써 직원의 이직을 줄이기 위한 방안을 모색하고 추후 이와 관련된 연구의 방향을 제시하는 것이다. 본 연구의 가설을 검증하기 위하여 AMOS 4.0과 SPSS 10.0 통계 프로그램을 이용하였으며, 분석 방법은 신뢰도분석(reliability analysis), 빈도분석(frequency analysis), 확인적 요인분석(confirmatory factor analysis), 상관관계 분석(correlation analysis) 그리고 공분산 구조분석(covariance structure analysis)을 실시하였다. 연구 결과, 핵심자기평가는 일-가족 방향 지원과 가족-일 방향 지원 모두에 긍정적인 영향이 있는 것으로 밝혀졌다. 일-가족 지원과 직장만족의 관계에 있어서는 가족-일 방향 지원만이 직장만족에 긍정적인 영향이 있는 것으로 나타났다. 마지막으로 직장만족은 직원의 이직을 줄이는 것에 효과가 있는 것으로 규명되었다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집C
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• pp.333-338
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• 2001

Fault tree is a widely used methodology for analyzing product reliability. The fault trees are usually constructed using the experiences of expert reliability engineers in top-down approaches and have different structures according to each expert's subjectivity. In this work it is tried to find a general method for the fault tree construction based on the function tree that is the result of product function deployment. Based on the function tree, the method has the advantage of resulting an objective fault tree since the faults are defined as the opposite concept of functions. The fault tree construction of this work consists of the following steps: 1) definition of product primary function with the viewpoints of product operation and configuration, 2) construction of functional relation chart using a grouping algorithm, 3) abstraction of functional block diagram according to operation sequences and configuration of a product, 4) construction of function tree for each viewpoint, and 5) construction of fault tree by matching the function tree and simplification of the result.

• 대한간호학회지
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• 제44권2호
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• pp.209-218
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• 2014

Purpose: The purpose of this study was to develop an instrument to assess bullying of nurses, and test the validity and reliability of the instrument. Methods: The initial thirty items of WPBN-TI were identified through a review of the literature on types bullying related to nursing and in-depth interviews with 14 nurses who experienced bullying at work. Sixteen items were developed through 2 content validity tests by 9 experts and 10 nurses. The final WPBN-TI instrument was evaluated by 458 nurses from five general hospitals in the Incheon metropolitan area. SPSS 18.0 program was used to assess the instrument based on internal consistency reliability, construct validity, and criterion validity. Results: WPBN-TI consisted of 16 items with three distinct factors (verbal and nonverbal bullying, work-related bullying, and external threats), which explained 60.3% of the total variance. The convergent validity and determinant validity for WPBN-TI were 100.0%, 89.7%, respectively. Known-groups validity of WPBN-TI was proven through the mean difference between subjective perception of bullying. The satisfied criterion validity for WPBN-TI was more than .70. The reliability of WPBN-TI was Cronbach's ${\alpha}$ of .91. Conclusions: WPBN-TI with high validity and reliability is suitable to determine types of bullying in nursing workplace.

• 한국BIM학회 논문집
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• 제4권4호
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• pp.1-12
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• 2014

As interest for visualization and real time processing of construction management information was heightened recently, a diversity of management tools have been developed and corresponding systems also have been changed. In the case of BIM(Building Information Modeling) which is being spotlighted as such kind of management tool, its outcome such as technical innovation and time saving through overseas success case, reducing effect of unnecessary work, and so forth has continuously been established. The BIM in which various information related with life cycle of project are managed with the base of 3D object is useful as an information management tool of construction project which becomes complex and large in its scale. The aim of this paper is analysis or reliability on BIM design for expressway. To solve these issues, this study analyzes the design document, road design handbook, guide. Also this paper performed analysis of reliability 2D vs. BIM quantity calculation. This pilot projects "BIM design at Daegu expressway Lot No.5" lays the foundation for future work on BIM based civil engineering design.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.32-35
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• 2002

The work focuses on the development of a Cu lead-frame with a single-sided adhesive tape for cost reduction and reliability improvement of LOC (lead on chip) package products, which are widely used for the plastic-encapsulation of memory chips. Most of memory chips are assembled by the LOC packaging process where the top surface of the chip is directly attached to the area of the lead-frame with a double-sided adhesive tape. However, since the lower adhesive layer of the double-sided adhesive tape reveals the disparity in the coefficient of thermal expansion from the silicon chip by more than 20 times, it often causes thermal displacement-induced damage of the IC pattern on the active chip surface during the reliability test. So, in order to solve these problems, in the resent work, the double-sided adhesive tape is replaced by a single-sided adhesive tape. The single-sided adhesive tape does net include the lower adhesive layer but instead, uses adhesive materials, which are filled in clear holes of the base film, just for the attachment of the lead-frame to the top surface of the memory chip. Since thermal expansion of the adhesive materials can be accommodated by the base film, memory product packaged using the lead-flame with the single-sided adhesive tape is shown to have much improved reliability. Author allied this invention to the Korea Patent Office for a patent (4-2000-00097-9).

• 근관절건강학회지
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• 제26권3호
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• pp.281-289
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• 2019

Purpose: This study aims to develop the Korean version of Presenteeism Scale for Students and verify its reliability and validity. Methods: This study conducted a survey with 320 undergraduate students who are attending nursing departments at three universities. The survey was conducted twice, from June 1 to August 31, 2017. Results: The Cronbach's α of K-PSS was .70 indicating high reliability. As a result of testing the content validity of K-PSS was verified by calculating the Item level-Content Validity Index (I-CVI) of .87. The correlation between Medical Outcome Study 36-item Short Form Health Survey (SF-36) score and Work Impairment Score (WIS), Work Output Score (WOS), Hours of absenteeism (HA) was analyzed to verify the concurrent validity of K-PSS. SF-36 score was correlated with WIS, WOS, HA. To test the differentiated validity of K-PSS, a total of 38 subjects were assessed by the paired t-test. As a result, only WIS score showed a significant difference between pre-test and post-test. Conclusion: Since the reliability and validity of the K-PSS developed through this study have been verified, it is expected to be used in various studies related to the presenteeism of students.

• 대한안전경영과학회지
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• 제22권2호
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• pp.31-38
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• 2020

The study evaluated the accuracy and intra-rater reliability for OWAS (Ovako Working posture Analysing System), RULA (Rapid Upper Limb Assessment), REBA (Rapid Entire Body Assessment) to improve their evaluation accuracy and reliability. Participants (n = 163) with undergraduate degree were recruited in this study and trained for 6 hours about the ergonomic assessment methods. Ergonomic assessments were conducted using OWAS, RULA, and REBA for a representative work with dynamic posture found in manufacturing industries. The study compared action categories (overall level) and detailed evaluation scores for individual body part. Action categories of the participants significantly differed from the golden reference defined by ergonomic experts. The participants underrated or omitted scores for truck (37.4% of the participants) and legs (52.8%) in OWAS. Similarly, the participants underrated or omitted additional scores for all body parts except the hand and wrist in RULA (53.5%) and REBA (54.8%). On the other hand, the participants overrated scores for the hand and wrist in RULA (55.2%) and REBA (39.9%). The results found in this study can help of selecting focus points and parts during assessment and education to improve accuracy and reliability of the ergonomic assessment methods.