목적 : 본 연구는 인지선별검사(Cognitive Impairment Screening Test; CIST)에 대한 신뢰도 및 타당 도를 조사고하자 한다. 연구방법 : 본 연구는 서울시에 거주하는 일반인 대상으로 CIST에 응답한 321명의 자료를 사용하였다. 총 321명이 응답 완료한 CIST 자료를 활용하여 신뢰도 분석을 위한 첫 번째 단계로 확인적 요인분석을 통해 일차원성 및 지역 독립성(local independence)의 가정을 조사하였다. 두 번째로, 일차원성 및 지역 독립성의 가정을 완료한 항목을 통해 라쉬 모형 중 부분점수모형(Partial Credit Model; PCM)을 적용 하여 항목 적합도, 항목 난이도 계층적 구조를 조사하였다. 마지막으로. 항목 간에 개인 특성으로 인한 차이를 분석하기 위해 차등항목기능을 조사하였다. 결과: 대상자의 평균 연령은 80.48세(SD = 6.59)였으며, 남성이 45명(14.02%), 여성이 276명(85.98%)이었다. 본 연구의 신뢰도 분석 첫 번째 단계로 진행한 CIST의 확인적 요인분석 결과, 일차원성과 지역 독립성 가정을 모두 충족 하였다. 두 번째로 진행한 라쉬 분석을 통해 분석된 항목 적합도는 6개 영역 모두 적합(0.6 < MnSq < 1.4, -2.0 < ZSTD < 2.0)하였으며, 가장 쉬운 항목은 지남력, 가장 어려운 항목은 집행기능으로 나타났다. 세 번째로, 성별에서 차등항목기능이 주의집중력 항목에서만 있는 것으로 조사되었다. 결론 : 본 연구에서는 신뢰도를 분석하여 CIST가 지역사회 노인을 대상으로 시행할 수 있는 인지선별검사 도구로 적절한 평가도구임을 확인하였다. 따라서 본 연구 결과를 통해 CIST를 사용하는 연구자 및 임상 가들에게 도움이 될 것으로 사료된다.

Guided missiles are a one-shot system that finishes their purpose after being used once, and due to the long-term storage until launch, the storage reliability is calculated during development, and performance is maintained through periodic inspections until the life cycle arrives. However, the reliability standards applied in the development of guided missiles were established by analyzing data accumulated by the United States during long-term operation in the country, and since they are different from our environment, the 00 guided missiles that have been deployed in the armed forces for more than 10 years under the premise that there is a difference from actual reliability. As a result of verifying the appropriateness of the current inspection cycle by analyzing the actual reliability of the missile, the necessity of changing the inspection period was derived because it was higher than the predicted reliability. It is proposed to build and utilize a lifespan management system that can systematically collect all data such as shooting and maintenance results by classification, and to establish a reliable reliability standard based on the accumulated data.

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.

Background: The Functional Assessment of Chronic Illness Therapy (FACIT) for Dyspnea was developed to assess multidimensional dyspnea using two subscales (experience of dyspnea and functional limitation) and a total score. Objects: This study aimed to assess the reliability and validity of the Korean version of the FACIT-dyspnea 10-item short form questionnaire (FACIT-dyspnea-K). Methods: Subjects were 163 patients with cancer. Dyspnea-related scales (modified Medical Research Council scale [mMRC], European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 [EORTC QLQ-C30], Hospital Anxiety and Depression [HAD], and WHO Performance Scale) were used to validate the FACIT-dyspnea-K. Results: Internal consistency was confirmed by Cronbach’s alpha values of 0.90 and 0.95 in factors 1 and 2, respectively. Convergence validity was determined by comparing the two factors and total score of the FACIT-dyspnea-K with conceptually related assessment tools measuring the physical and emotional effects of dyspnea, with which correlations ranged from 0.364 to 0.567. Criterion validity was established by significant differences in the FACITdyspnea- K score between groups when the patients were classified by performance status as assessed by the WHO performance scale. Furthermore, the FACIT-dyspnea-K showed notable correlations with other dyspnea scales (mMRC, EORTC QLQ-C30, and HAD) for cancer patients (r = 0.28 to 0.54). The test-retest reliability of the two factors and total score of the FACITdyspnea- K appeared to be excellent (Cronbach’s alpha = 0.96 to 0.97). Conclusion: This study supports FACIT-dyspnea-K as a valid and reliable instrument to assess the dyspnea experience of cancer patients in clinical settings.

PURPOSES : This study was purposed to investigate whether the current passing sight distance standard is appropriate. Therefore, to determine a safe passing sight distance, data collected from the observations of a two-lane road were implemented in reliability analysis to develop a realistic passing sight distance model. METHODS : First, passing sight distance data were collected for analysis from two-lane roads in Jeollabuk-do. Next, the speed profile was generated based on the collected data in order to analyze driver behavior. Finally, a model reflective of the driving behavior of motorists was developed and compared to the existing passing sight distance standard using reliability analysis. RESULTS : As compared to the existing model for safe passing sight distance, the actual speed of the overtaking vehicle indicated higher acceleration and a longer acceleration duration. The entire model, with exception of the d1 section, was modified to reflect the overtaking behavior of motorists d1. d2 was set to correspond to the time until the vehicles run side by side (t21); Time t22 was set to correspond to the time until subsequent recovery to the main lane, and d3 was set to range between 19 and 47 m following review of the actual passing sight distance data. In addition, d4 was computed to be two-thirds of the distance d2, and the oncoming car was found to drive at a constant speed that was similar to the speed associated with d2 . Analysis of the reliability of the existing Korean passing sight distance standard revealed that the current standard does not recommend a safe passing sight distance for drivers. CONCLUSIONS : As compared to the existing passing sight distance criterion, the actual speed and acceleration that driver apply to overtake a vehicle are higher, and the existing passing sight distance criterion is shorter than the actual passing sight distance. Additionally, the results of reliability analysis revealed that the proposed model developed to reflect driver overtaking behavior has more explanatory power than the existing one. Therefore, it is necessary to introduce new design standards that implement passing sight distance variables that are relevant to local drivers.

목적 : 본 연구의 목적은 활동분석과 프로세스 맵핑을 기반으로 한 Korean version of Modified Barthel Index(K-MBI) 가이드북을 제작하여 내용 타당도와 평가자 간 신뢰도 및 일치도를 확인하고자 하였다. 연구방법 : 본 연구에서는 활동분석과 프로세스 맵핑을 기반으로 한 K-MBI 가이드북을 개발하였다. 개발 된 K-MBI 가이드북에 대한 이해도 조사 및 수정을 하여 최종 가이드북을 제작하여 40명의 작업치료 전문가 집단에 내용 타당도를 검증하였다. 평가자 간 신뢰도 및 일치도 조사를 위해 기존의 K-MBI 검 사 지침에 근거하여 총 5명의 환자의 일상생활활동 동영상을 촬영하였다. 평가자 간 신뢰도와 일치도 조 사는 84명의 작업치료사가 교육 전과 후에 동일하게 동영상 속의 5명의 환자를 평가하여 확인하였다. 결과 : 내용 타당도 검증 결과는 개발된 K-MBI 가이드북 11개의 모든 항목에서 CVI 점수가 .93 이상으 로 높은 수준의 타당도를 나타내었다. 평가자 간 신뢰도에서는 ICC가 교육 전 .983, 교육 후에 .982로 교육 전과 후 모두 높은 수준의 신뢰도를 보였다. 정답률의 변화는 교육 전 48.37%에서 교육 후에 69.48%로 향상되었고, 평가자 간 일치도는 옷 입고 벗기 항목을 제외한 모든 항목에서 일치도가 향상 된 것으로 나타났다. 결론 : 본 연구의 결과를 통해 활동분석 및 프로세스 맵핑을 기반으로 한 K-MBI 가이드북은 일상생활활 동 평가에서 평가자 간의 신뢰도와 일치도를 향상되게 시키는 것으로 확인되었다.

As the functions and structure of the system are complicated and elaborated, various types of structures are emerging to increase reliability in order to cope with a system requiring higher reliability. Among these, standby systems with standby components for each major component are mainly used in aircraft or power plants requiring high reliability. In this study, we consider a standby system with a multi-functional standby component in which one standby component simultaneously performs the functions of several major components. The structure of a parallel system with multifunctional standby components can also be seen in real aircraft hydraulic pump systems and is very efficient in terms of weight, space, and cost as compared to a basic standby system. All components of the system have complete operation, complete failure, only two states, and the system has multiple states depending on the state of the component. At this time, the multi-functional standby component is assumed to be in a non-operating standby state (Cold Standby) when the main component fails. In addition, the failure rate of each part follows the Weibull distribution which can be expressed as increasing type, constant type, and decreasing type according to the shape parameter. If the Weibull distribution is used, it can be applied to various environments in a realistic manner compared to the exponential distribution that can be reflected only when the failure rate is constant. In this paper, Markov chain analysis method is applied to evaluate the reliability of multi-functional multi-state standby system. In order to verify the validity of the reliability, a graph was generated by applying arbitrary shape parameters and scale parameter values through Excel. In order to analyze the effect of multi-functional multi-state standby system using Weibull distribution, we compared the reliability based on the most basic parallel system and the standby system.

PURPOSES :The purpose of this study is to perform a reliability analysis of the proposed wind load combination which governs the design of support structures of subsidiary road facilities, and to evaluate whether the target reliability of the design is satisfied.METHODS :The statistical estimation method is applied and the design period of the support structure is used to obtain the statistical property of the wind load. In addition, the statistical properties of the strength of support structures are obtained from a literature review and simulation study. Actual support structures are designed by the proposed load combination and are used as the examples to examine if the target reliability is obtained.RESULTS :The result of the reliability analysis performed by using the statistical properties of load and resistance for the support structure in this study indicates that the proposed wind load combination satisfied the target reliability index of the design. Also, the convenience of the design is achieved by adopting the same design wind velocity given in the bridge design code by applying the wind velocity ratio defined for the design period of the support structure.CONCLUSIONS :It is presented that the design using the wind load combination proposed in this study achieved the target reliability index and the design wind load for different design periods can be conveniently defined by applying the velocity ratio proposed in this study.

When weapon system is designed and developed, a reliability is one of important factors to determine the development goal. The reliability analysis of the weapon system and equipment is based on MIL Specification, MIL-HDBK-217F and MIL-HDBK-338B. And the weapon system is operated on various environments by operating concept of the military using the weapon system. This study, at first, present failure rate by PSA comparing with failure rates by PCM, the different reliability analysis method, for same CCA(Circuit Card Assembly). And the study present change of reliability analysis results for CCA on various operation environment condition..

In cloud and game servers, SSDs are used as cache on large capacity disk-based storage. In that configuration, the SSD can be exploited as write-back or write-through cache. Though the write-back cache can improve write performance significantly, data can be lost when the SSD fails. On the contrary, performance improvement is limited in the write-through cache though it has high reliability. By the way, reliability can be improved by applying RAID technique to SSD cache while exploiting write-back for better performance. In this paper, we analyse the reliability and the performance of hybrid storage using SSD cache over disk-based primary storage. In particular, we mathematically analyse reliability and also measure performance of real storage systems with various SSD cache configurations.

본 연구에서는 질병 데이터를 활용한 사망률의 지도화에서 지역별 사망률의 변동성을 안정화할 수 있도록 하는 베이지언 기법을 적용하고, 기본적으로 활용되고 있는 SMR (Standardized mortality ratio)과 그 결과를 비교하였다. 우리나라 전국의 시군구 단위의 전립선암 사망자 수 데이터에 표준화와 베이지언 기법을 적용하고, 산출된 사망률을 지도화하여 기존에 없던 우리나라의 전립선암 사망률 지도를 질병 지도의 예시 자료로 작성하였다. 분석 결과, Bayesian 모델링 기법을 통해 계산된 위험비는 기존 SMR에 비해 좀 더 수렴된 형태의 안정적인 통계량을 가지는 것을 알 수 있었다. 국지적 Bayesian 기법은 이웃 지역들의 정보만을 반영하여 위험비를 평활화하기 때문에 본 연구에서 사용된 전역적 기법들과 비교할 때 평활화의 강도가 크지 않았다.

In industrial situation, electronic and electro-mechanical systems have been using different type of batteries in rapidly increasing numbers. These systems commonly require high reliability for long periods of time. Wider application of battery for low-power design as a prime power source requires us knowledge of failure mechanism and reliability of batteries in terms of load condition, environment condition and other explanatory variables. Battery life is an important factor that affects the reliability of such systems. There is need for us to understand the mechanism leading to the failure state of battery with performance characteristic and develop a method to predict the life of such battery. The purpose of this paper is to develope the methodology of monitoring the health of battery and determining the condition or fate of such systems through the performance reliability to predict the remaining useful life of primary battery with load condition, operating condition, environment change in light of battery life variation. In order to evaluate on-going performance of systems and subsystems adopting primary batteries as energy source, The primitive prototype for performance reliability analysis device was developed and related framework explained.

본 연구는 감성분석기법이 디자인 평가에 적극 적용되어지면서 발생할 수 있는 감성평가모형의 사용상의 오 류를 최소화 하는데 연구의 목적이 있다. 제품, 실내 공간, 가로경관 디자인 분야별로 축약형 모형의 어휘 추출을 위해 선행연구에서 발췌한 어휘로 1차적인 어휘정제작업을 수행하였다. 세 분야에서 공통적으로 사용되는 어휘 19개가 나타났는데 신뢰도 분석 결과, 분야별로 신뢰도에 좋지 않은 영향을 끼치는 어휘들이 각각 다르게 나타 났다. 축약형 모형인 EPA모형과 추론형 모형인 PAD모형의 신뢰도 분석을 통한 어휘 적합성을 검토하였다. 결과, 세 분야에서 축약형 모형이 추론형 모형보다 신뢰도가 높게 나타났지만, 계수의 차이가 크지 않았다. 또한 신뢰도에 좋지 않은 영향을 끼치는 어휘들을 삭제하고 신뢰도 분석 한 결과 계수의 차이가 확연히 높은 신뢰도가 나 타났다. 따라서 감성평가 시에는 평가대상에 적합한 어휘 선정 과정이 필요하고, 적합한 모형을 사용하는 것이 감성평가의 객관성을 높이는 방법으로 사료된다. 추후 환경 평가에 적합한 감성평가모형의 분석이 신뢰도 검증 외에 다양한 통계기법에 의해 분석되어져야 한다.

The purpose of this paper is to examine the effects on reliability of equipment or product which spends a great deal of its time in the non-operating condition. The paper will look at the effects on the failure modes, the failure rates, the failure distribution and the possible reliability models. Many military and commercial systems experienced periods of non-operating stage throughout their life cycle, such as periods of operational storage where the system waits, ready for use. The design of such systems must account for how these periods of non-operating effects system performance. The simulation methodology for reliability analysis was developed to support the evaluation of nonoperating modes of operation of systems and subsystems. For proper handling of the non-operating environment, issues relating to non-operating failures need to be taken into consideration from design stage of the life cycle. Furthermore, the relevant environmental concerns and issues that need to be taken into consideration are discussed.

Reliability measures of questionnaire and  contingency tests of categorized responses are most practical tools to analyze the characteristics of subjects of survey study. This research evaluates the Cronbaha’s reliability measures by using Repeated Measure Design (RMD) with illustrated MINITAB examples. In addition,  statistics of each cell of categorized tables can be effectively interpreted with the symmetric plot of correspondence analysis. The practical example is also discussed to provide comprehensive understanding of topic.

국내 고속도로의 교량은 2000년 이후 집중된 선형개량 및 신규 노선 증가 사업으로 10년 전과 비교하여 2배 이상 증가하였다. 이에 따라 유지관리 비용도 지속적으로 증가하고 있다. 현재 고속도로 유지관리 예산 비중이 가장 높은 항목은 아스팔트 교면 교량의 콘크리트 바닥판 열화에 의한 보강 부분이다. 2011년 고속도로 관리교량은 약 7,800여개에 도달한 시점에서 현재 방법으로는 향후 어느 정도 바닥판 보강 예산이 필요한지 어느 시기에 증액을 하여야되는지 명확하게 추정하기 어렵다. 본 연구에서는 신뢰도 분석 방법인 와이불 분포에 의한 생존 수명 예측 기법을 적용하여 현재 고속도로 아스팔트 계열의 교면 교량의 평균 수명을 추정하였고 이를 토대로 향후 예상 보강 비용을 추정하였다.

At a zone of operations or underwater mine warfare, it's very critical for warship to be damaged by underwater mine. In order to increase survival rate of warship from threat of mine, specific signal of warship is measured. And then specific signal is treated and calibrated below the baseline. The sensors that measured the signal are installed under the sea to exactly measure. It's difficult for maintenance men to approach the underwater equipment compared with the ground equipment. It needs long time for maintaining, demands support equipments and handling equipment. And it needs people who maintain the equipment under the water. So, it's important to analysis accurate reliability and estimate maintenance period. This paper present the reliability analysis method about array sensors under the water. The analysis object, array sensors, is set bounds to a warship signal measurement facility. At First, this study established procedure of reliability analysis about array sensors under the water and analyzed the structure of array sensors. It decided number of sensors which was depended on size of warship and selected reliability model through considering the structure and operational concept. Finally, it calculated MTBF(Mean Time Between Failures) of array sensors under the water.