• 해양환경안전학회지
• /
• 제21권3호
• /
• pp.297-302
• /
• 2015

To prevent cargo accidents by repeated loads, a continuous monitoring for securing rope or additional safety measures are needed, but most of prevention measures have been conducted only by operator's own experience not a quantitative assessment. Hence, the Load-Displacement curve and approximation formula of securing rope were drawn in this research for a quantitative assessment and simplified measurement on a tension of securing rope using a tensiometer. Moreover, a com parison was conducted between m easuring tension and calculated tension on securing rope with portable tensiometer, 'Load-Displacement' approximation formula. The calculated tension of securing rope is obtained 153.3kfg using the formula and that result has not much difference with initial tension 150.0kgf. Lastly, an analysis of the characteristics of various ropes was suggested to enhance the reliability about quantitative assessment of securing rope's tension through further research.

• 대한산업공학회지
• /
• 제21권4호
• /
• pp.463-477
• /
• 1995

This paper presents a decision model that will estimate the expected number of failed units in a repair facility in accordance with the varying demand, and determine the required number of personnel for repairing components. The demand is related to the failure process which follows a reliability growth phenomenon in service. The information in this paper is useful for selecting appropriate scheduling rules and spares stocking policies. SIMAN and FORTRAN were used for computing the time dependent performance measures in the repair facility. The numerical integration method that is presented in this paper will provide accurate performance measures with any dynamic pattern of demand, service rates, and any number of servers.

• 한국식품조리과학회지
• /
• 제19권2호
• /
• pp.155-164
• /
• 2003

The purpose of this study was to examine, in a service context, construct validity and generalizability of widely used and accepted measures of perceived organizational support, job satisfaction, organizational commitment, and service duality, and to test each measures' predictive utility in this context with path analysis. Of 350 subjects, 309 subjects participated in the analysis. Descriptive statistics (frequencies), exploratory factor analysis, reliability analysis, zero-order partial correlation analysis, and confirmatory factor analysis were used for this study. The findings from this study are as follows. First, perceived organizational support significantly influenced job satisfaction, organizational commitment. and service quality. Second, Job satisfaction had a directional impact upon organizational commitment and service quality. Third, organizational commitment showed to have a predictive impart on service quality. Finally, the results of the study provide some insight into the types of internal marketing strategies that can be applied successfully by operators of hotel F & B departments.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2008년도 추계학술대회 논문집
• /
• pp.2040-2044
• /
• 2008

Recently, many safety measures are developing for the prevention of human error, which is main factors of railway accident. For the efficient management of human factors, many expertise on design, conditions, safety culture and staffing are required. But current safety management activities on safety critical works are focused on training, due to the limited resource and information. In order to establish railway human factors management, a systematic review model is required. Based on system engineering and nuclear industry model, a program review model is proposed in this study. The model includes operating experience review, task analysis, staffing and qualification, human reliability analysis, huma-system interface design, procedure development, training program, verification and validation, implementation and monitoring. Results can be applied for the review of safety measures relating to human factors.

• Communications for Statistical Applications and Methods
• /
• 제30권2호
• /
• pp.191-213
• /
• 2023

Unit distributions are frequently used in probability theory and statistics to depict meaningful variables having values between zero and one. Using convenient transformation, the unit inverse exponentiated weibull (UIEW) distribution, which is equally useful for modelling data on the unit interval, is proposed in this study. Quantile function, moments, incomplete moments, uncertainty measures, stochastic ordering, and stress-strength reliability are among the statistical properties provided for this distribution. To estimate the parameters associated to the recommended distribution, well-known estimation techniques including maximum likelihood, maximum product of spacings, least squares, weighted least squares, Cramer von Mises, Anderson-Darling, and Bayesian are utilised. Using simulated data, we compare how well the various estimators perform. According to the simulated outputs, the maximum product of spacing estimates has lower values of accuracy measures than alternative estimates in majority of situations. For two real datasets, the proposed model outperforms the beta, Kumaraswamy, unit Gompartz, unit Lomax and complementary unit weibull distributions based on various comparative indicators.

• 전기학회논문지P
• /
• 제64권4호
• /
• pp.212-219
• /
• 2015

Korea's first tram (so called "tram"), which was commenced the operation on May 4, 1899 of late Joseon Dynasty and run until 1968, played a pivotal role of public transportation. However, tram as new transportation mean is being recognized as traffic congestion problem becomes issue due to geometric automobile increase and reckless urban plan after stoppage of tram service. Tram has an advantage of inexpensive construction cost and eco-friendly means compared to existing and city railway, carrying more passengers rather than existing bus, excellent connectivity of existing transportation because of easy accessible to destination in the city center. Therefore, tram, what is called "Green Rvolution of Public Transportation", has a dreaming of revival and in the process of pushing. We suggest the accident type which might break out in the early stage of tram introduction and preventive measures by surveying the accident cases of tram advanced country, and study the crossing control measures.

• 융합보안논문지
• /
• 제20권2호
• /
• pp.53-58
• /
• 2020

지식정보사회에서 기업의 비즈니스 연속성을 담보하기 위한 가용성의 중요성이 대두되면서, 가용성 보장전략으로 지속적인 서비스 인프라를 구축하는 고가용성(HA, High Availability) 구현 방안을 제시하고 있다. 하지만, 정보자산에 대한 중요도 평가의 신뢰도가 확보되지 않는다면 실제 자산의 가치와 연계되어 보안성을 유지하기 어렵기 때문에 자산가치 매트릭스를 통해 평가된 자산 중요도를 바탕으로 가용성 기준인 서비스 유지 평가항목과 매핑하여 관리할 수 있는 가용성 평가 방안이 필요하다. 이에 본 연구에서는 정보 자산에 대한 가용성 평가 방안을 제시한다.

• Journal of the Korean Data and Information Science Society
• /
• 제23권1호
• /
• pp.25-37
• /
• 2012

두 평정자간 평가의 일치정도를 나타내는 합치도로 Cohen (1960)의 ${\pi}$, Scott (1955)의 H, 박미희와 박용규 (2007)의 등 많은 통계량이 제안되어왔다. 모의실험을 통하여 균형적 주변분포에서의 명목형과 순서형 합치도, 두 가지 역설이 발생하는 불균형 주변분포에서의 명목형 합치도들의 편의, 표준오차, 평균오차제곱 분산, 변이계수를 비교한 결과, 모든 경우에서 AC1과 H의 표준오차와 변이계수가 가장 작게 나타났다.

• 산업경영시스템학회지
• /
• 제44권3호
• /
• pp.22-32
• /
• 2021

To meet rapidly changing market demands, manufacturers strive to increase both of productivity and diversity at the same time. As a part of those effort, they are applying flexible manufacturing systems that produce multiple types and/or options of products at a single production line. This paper studies such flexible manufacturing system with multiple types of products, multiple Bernoulli reliability machines and dedicated buffers between them for each of product types. As one of the prevalent control policies, priority based policy is applied at each machines to select the product to be processed. To analyze such system and its performance measures exactly, Markov chain models are applied. Because it is too complex to define all relative transient and its probabilities for each state, an algorithm to update transient state probability are introduced. Based on the steady state probability, some performance measures such as production rate, WIP-based measures, blocking probability and starvation probability are derived. Some system properties are also addressed. There is a property of non-conservation of flow, which means the product ratio at the input flow is not conserved at the succeeding flows. In addition, it is also found that increased buffer capacity does not guarantee improved production rate in this system.

• 말소리와 음성과학
• /
• 제6권4호
• /
• pp.195-203
• /
• 2014

The aim of this study was to investigate the effects of phonation types ([+/- aspirated], [+/- fortis]) on aerodynamic measures with Korean bilabial stops. Sixty-three healthy young adults (30 males, 33 females) participated to evaluate the VOEF (Voicing Efficiency) tasks with bilabial stop consonants /$p^h$/, /p/, /p'/ using Phonatory Aerodynamic System (PAS) Model 6600 (Kay PENTAX Corp, Lincoln Park, NJ). All VOEF measures were significantly influenced by phonation types except RANP(pitch range)(p <.01). For sound pressure, maximum SPL, mean SPL, and Mean SPL during Voicing have been shown to be significantly greatest in fortis stop /p'/ than aspirated /$p^h$/ and lenis stop /p/ (p<.001). On the other hand, mean pitch after lenis stop was significantly lower than after aspirated and fortis stops (p<.001). Peak expiratory airflow, Target airflow, and FVC (Expiratory volume) were significantly lowest in fortis stop /p'/ which might be associated with higher aerodynamic resistance while peak air pressure and mean peak air pressure during closure were significantly lower in lenis stop /p/. Additionally, AEFF (Aerodynamic efficiency) was significantly higher in fortis stop /p'/ than lenis stop /p/ as well as aspirated stop /$p^h$/ (p<.001). Thus, sound pressure, airflow parameters, and aerodynamic resistance made crucial roles in distinguishing fortis /p'/ from lenis stop /p/ and aspirated. Additionally, pitch and subglottal air pressure parameters were important aerodynamic characteristics in distinguishing lenis /p/ from fortis /p'/ and aspirated /$p^h$/. Therefore, accurate aspirated /p/ stop consonant should be elicited when collecting the airflow, intraoral pressure related data with patients with voice disorders in order to enhance the reliability and relevance or validity of aerodynamic measures using PAS.