• Journal of the Korean Data and Information Science Society
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• 제27권3호
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• pp.711-724
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• 2016

다양하게 변화하는 복잡한 생존환경 하에서는 여러 요인이 동시에 사람이나 시스템의 수명에 영향을 줄 수 있다. 본 연구에서는 여러 요인이 동시에 수명에 영향을 주면서, 영향력의 크기가 상황에 따라 동적으로 변화하는 신뢰성 모형에 관한 연구를 수행한다. 수명에 영향을 주는 요인으로, 자연적 고장과 더불어, 하나의 개체의 사망이나 고장으로 인한 잔여 개체에 대한 스트레스 증가, 외부 충격, 그리고 생존 환경 스트레스 수준을 동시에 고려한다. 이들 요인들을 모두 포함하는 두 가지 모델을 고려하고, 이변량 수명 분포를 유도한다. 또한 이들 두 모형을 서로 비교하며, 이들 모형으로부터 얻어지는 최대값의 분포와 최소값의 분포를 비교하고자 한다. 제안된 두 가지 신뢰성 모형에서의 최대값 분포와 최소값 분포의 비교를 위하여 확률적 순서화에 관한 개념을 소개하며, 이에 기초하여 최대값 분포와 최소값 분포에 대한 확률적 비교를 수행한다.

• 대한기계학회논문집A
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• 제36권7호
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• pp.751-757
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• 2012

사용조건에서 수명시험을 수행할 경우 시험시간이 많이 소요되므로 사용조건보다 가혹한 스트레스 조건을 추가하여 가속수명시험을 수행하면 시험시간을 단축시킬 수 있다. 수명에 영향을 미치는 스트레스를 선정하여 각 스트레스의 사용조건과 가속조건에서 시험을 수행할 경우 가속 스트레스간에 교호작용이 존재할 수 있다. 그러나 기존의 연구에서는 2가지 이상의 가속 스트레스를 부과하여 가속수명시험을 수행할 경우 교호작용을 고려하지 않은 경우와 가속 수명에 대한 모델식을 제시한 연구들이 대부분이다. 본 논문에서는 기계류 부품의 수명에 영향을 미치는 가속 스트레스를 선정한 후 교호작용을 고려한 시험계획에 따라 가속수명시험을 수행한 자료를 이용하여 가속 계수와 가속 스트레스간의 관계식을 산출하는 방법을 제시하고자 한다. 또한 본 논문에서 제시한 교호작용을 고려한 가속시험방법과 가속 계수를 산출할 수 있는 모델식을 이용하여 복합적인 가속수명시험 수행시 쉽게 적용하고 결과를 산출할 수 있는 기초가 될 것으로 기대된다.

• 대한간호학회지
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• 제32권5호
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• pp.599-608
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• 2002

Purpose: The purposes of this study were to test the validity and reliability of FACES III when applied to the only one and two family members, and to use more appropriately in the nursing practice. Method: Data were collected from 105 college students and 105 of their parents in two local nursing colleges. The original questionnaire, which was originally developed by Olson(1989), was modified by based on literature review and analyzed by correlation coefficient, Cronbach's α, Guttmans split coefficients and factor analysis. Result: Cronbach's αof the adaptability and cohesion were .77, .73(Guttmans split coefficient were .76, .71) when applied to the only one family member, and were .81, .77 (Guttmans split coefficient were .81, .77) when applied to two. The Pearson's correlation coefficient of the adaptability and cohesion between two family members were .38, .35. The total-item correlations of the other items except for items 5, 7, 13 were significant. The correlation coefficients between adaptability and cohesion when applied to only one and two were .30, .38(p < .01). When the data was analyzed by principle component analysis and Varimax rotation with the number of factors fixed to two, two factors explained 37.2% of total variance in the case of one member, and 42.2% of total variance in two. Conclusion: These results suggested that the concept and the construction validity of cohesion needed to be more clarified. Also It is required that the reliability and validity of FACES III should be tested in two more family members.

• 대한통합의학회지
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• 제12권2호
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• pp.65-76
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• 2024

Purpose : This study aimed to develop and validate a reliable tool, the Korean physical therapists' work environment scale (K-PTWES), for assessing the work environment of Korean physical therapists. The study also sought to examine the validity and reliability of the instrument. Methods : This methodological study involved the development and testing of the measurement tool. The conceptual framework was established through a literature review and in-depth interviews with clinical physical therapists. A total of 40 meaningful statements emerged from this process, leading to the generation of 29 primary items. Following a content validity test, 29 items were selected for the preliminary tool. Data were collected from 220 physical therapists across various job roles and unit types, such as outpatient and inpatient physical therapy rooms in domestic hospitals, with more than one year of experience. The final analysis included data from all 220 physical therapists. Results : Varimax rotated principal component analysis was employed for validities, revealing four factors: organizational support, working system, sustainable development, and relationship with coworkers, explaining a total variance of 54.97 %. The Cronbach's α coefficient for the final tool was .939, indicating high reliability. Conclusion : In this study, we developed a measurement tool reflecting the characteristics of the Korean physical therapists' work environment scale (K-PTWES). Our findings highlight the tool demonstrated both validity and reliability. Utilizing this tool is expected to contribute to understanding the work environment of Korean physical therapists and fostering a healthy work environment. Based on our findings, we recommend, firstly, conducting research on the work environment and related factors of physical therapists working in diverse settings using the K-PTWES. Secondly, future studies should focus on validating the tool's criterion-related validity, as it was not addressed in this research.

• 대한안전경영과학회지
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• 제18권1호
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• pp.219-226
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• 2016

As the development environment is changing with the development of information communication technology, the systems that were used by each service became used with integration. In the process of integrating from existing legacy systems to new system, it should be smoothly integrated or shared, however, it cannot help holding existing technology or component due to significant cost burden for conversion. In this paper, it was not only classified by types with analyzing the various elements that make up legacy system but an approach and monitoring system were developed to each type. After System application results, data's information generated in each process is provided to other system in real time, so that it has not only secured the work efficiency and reliability but also it is made possible by integrating data in various formats for efficient data management, rapid search and tracking to history. With real-time monitoring system developed in this study, It can be very useful in a variety of industries which require real-time monitoring of distributed legacy system data.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2004년도 The 3rd Annual Conference for The Korean Society for Bioinformatics Association of Asian Societies for Bioinformatics 2004 Symposium
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• pp.107-116
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• 2004

The advent of microarray technologies gives an opportunity to moni tor the expression of ten thousands of genes, simultaneously. Such microarray data can be deteriorated by experimental errors and image artifacts, which generate non-negligible outliers that are estimated by 15% of typical microarray data. Thus, it is an important issue to detect and correct the se faulty probes prior to high-level data analysis such as classification or clustering. In this paper, we propose a systematic procedure for the detection of faulty probes and its proper correction in Genechip array based on multivariate statistical approaches. Principal component analysis (PCA), one of the most widely used multivariate statistical approaches, has been applied to construct a statistical correlation model with 20 pairs of probes for each gene. And, the faulty probes are identified by inspecting the squared prediction error (SPE) of each probe from the PCA model. Then, the outlying probes are reconstructed by the iterative optimization approach minimizing SPE. We used the public data presented from the gene chip project of human fibroblast cell. Through the application study, the proposed approach showed good performance for probe correction without removing faulty probes, which may be desirable in the viewpoint of the maximum use of data information.

• 제어로봇시스템학회논문지
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• 제13권3호
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• pp.230-234
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• 2007

Generally, huge amounts of data traffic are generated by using broadcasting method to deliver sensing data to a sink node reliably so that it makes a severe network saturation problem resulting in unreliable data transfer. In order to handle this problem, a new congestion control protocol is required for supporting reliable data transfer, minimal use of energy and network resources at the same time in wireless sensor networks. In this paper, it proposes a Protocol to guarantee both a reliable transfer in data accuracy and minimum consumption of energy waste by using Hop-by-Hop sequence number and DSbACK(Delayed and Selective ACK Buffer Condition) scheme. In addition, it proves that reliability and energy efficiency are enhanced by the proposed method with the simulation results performed on TinyOS platform which is a component based built-in OS announced by UC Berkely with the performance comparison of other existing methods.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.533-538
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• 2014

Power generator is one of the most important component of electricity generation system to convert mechanical energy to electrical energy. I t designed robustly to maintain high system reliability during operation time. But unexpected failure of the power generator could happen and it cause huge amount of economic and social loss. To keep it from unexpected failure, health prognostics should be carried out In this research, We developed a health prognostic method of stator windings in power generator with statistical data analysis and degradation modeling against water absorption. We divided whole 42 windings into two groups, absorption suspected group and normal group. We built a degradation model of absorption suspected winding using Fick's second law to predict upcoming absorption data. Through the analysis of data of normal group, we could figure out the distribution of data of normal windings. After that, we can properly predict absorption data of normal windings. With data prediction of two groups, we derived upcoming Directional Mahalanobis Distance (DMD) of absorption suspected winding and time vs DMD curve. Finally we drew the probability distribution of Remaining Useful Life of absorption suspected windings.

• 융합정보논문지
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• 제11권9호
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• pp.138-144
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• 2021

전자부품 조립사업은 제품불량이 발생했을 때, 입고된 원자재불량 또는 작업불량을 추적하는 것이 중요하며, 결과에 따라 납품업체 또는 작업현장 개선이 중요하다. 스마트팩토리의 핵심 과제는 데이터 통합허브를 구축하여 저장·관리·분석을 실시간으로 처리하고 클러스터공정, 에너지, 환경, 안전을 통합관리 하는 것이다. 전자부품 관련 중소기업에 생산현장관리를 실시간 모니터링하여 생산데이터의 정확한 분석과 수집으로 신뢰도를 향상시키기 위해서는 스마트팩토리 구축이 필수적이다. 본 논문은 스마트팩토리를 도입하고자 하는 전자 부품관련 중소기업의 특성을 고려해 시스템 구성방법, 스마트팩토리 관련기술 과 적용사례 등을 정의하여 구축에 활용토록 개발되었다.

• Child Health Nursing Research
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• 제18권2호
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• pp.53-59
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• 2012

Purpose: This study was done to verify the reliability and validity of the Korean version of DMCI in Korean adolescents. Methods: A methodological study design was used with Cronbach's ${\alpha}$ for reliability, and an exploratory factor analysis and contrasted groups approach for construct validity. DMCI was translated into Korean and tested with a sample of 406 adolescents in Korea. The data were analyzed using Cronbach's ${\alpha}$, item correlation with total, principal component factor analysis, and t-test. Results: The translated content of the DMCI was validated by nursing faculty members and translation equivalency was obtained. The Cronbach's ${\alpha}$ of the DMCI simplified with 18 items was .78. The factor analysis revealed three factors explaining 41.5% of total variance and the corresponding factors were self-observation (21.6%), self-judgement (11.4%), and self-confidence (8.6%). The mean score for the DMCI in the aggression group was significantly lower than the non-aggression group. Conclusion: Results of this study suggest that the Korean version of DMCI can used as a reliable and valid measure to assess decision making competency in Korean adolescents.