• 한국안전학회지
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• 제15권4호
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• pp.150-156
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• 2000

In this paper, the human error contributions to the system unavailability are calculated and compared to the mechanical failure contributions. The system unavailability is a probability that a system is in the failed state at time t, given that it was the normal state at time zero. It is a function of human errors committed during maintenance and tests, component failure rates, surveillance test intervals, and allowed outage time. The THERP (Technique for Human Error Rate Prediction), generally called "HRA handbook", is used here for evaluating human error rates. This method treats the operator as one of the system components, and human reliability is assessed in the same manner as that of components. Based on the calculation results, the human error contribution to the system unavailability is shown to be more important than the mechanical failure contribution in the example system. It is also demonstrated that this method is very flexible in that it can be applied to any hazardous facilities, such as gas valve stations and chemical process plants.ss plants.

• 한국통신학회논문지
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• 제34권2A호
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• pp.164-169
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• 2009

본 논문에서는 와이브로 시스템을 위한 빠르고 정확한 레인징 알고리즘에 대해 소개한다. 제안된 알고리즘은 PRBS(Pseudo Random Binary Sequence)의 상관 특성과 DFT의 circular shift 특성을 이용하여 수신된 레인징 코드를 결정하고 전파 지연을 추정한다. 제안된 레인징 알고리즘을 어레이 안테나 시스템에 적용하여, 단일 안테나 시스템과 비교해 어떻게 레인징 성능을 향상시킬 수 있는지를 알아본다.

• Nuclear Engineering and Technology
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• 제29권1호
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• pp.1-6
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• 1997

This paper presents a new dynamic approach for assessing feasibility associated with the implementation of accident management strategies by the operators. This approach includes the combined use of both the concept of reliability physics and a dynamic event tree generation scheme. The reliability physics is based on the concept of a comparison between two competing variables, i.e., the requirement and the achievement parameter, while the dynamic event tree generation scheme on the continuous generation of the possible event sequences at every branch point up to the desired solution. This approach is applied to a cavity flooding strategy in a reference plant, which is to supply water into the reactor cavity using emergency fire systems in the station blackout sequence. The MAAP code and Latin Hypercube sampling technique are used to determine the uncertainty of the requirement parameter. It has been demonstrated that this combined methodology may contribute to assessing the success likelihood of the operator actions required during accidents and therefore to developing the accident management procedures.

• 한국정밀공학회지
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• 제16권3호통권96호
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• pp.91-102
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• 1999

Fieldbus provides real-time data communication among field devices in the manufacturing automation and process control systems. In this study, an experimental model of fieldbus-based manufacturing automation system is developed. Experimental model consists of two robots, two conveyor belts, NC machine, PLC, sensors and operator station. These machines are interconnected into the Profibus network, and exchange their data through the services provided by FMS(Fieldbus Message Specification), which is the application layer protocol of Profibus. The experimental model is used to measure the network-induced delay of variable and file data transmitted through FMS services. Network-induced delays are collected and analyzed on each sublayer of Profibus protocol stack. The results obtained from the experiment of this study can be effectively utilized when fieldbus is implemented on the practical manufacturing automation systems.

• International Journal of Reliability and Applications
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• 제2권1호
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• pp.37-48
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• 2001

This paper presents a new dynamic human reliability analysis method and its application for quantifying the human error probabilities in implementing management action. For comparisons of current HRA methods with the new method, the characteristics of THERP, HCR, and SLIM-MAUD, which are most frequency used method in PSAs, are discussed. The action associated with implementation of the cavity flooding during a station blackout sequence is considered for its application. This method is based on the concepts of the quantified correlation between the performance requirement and performance achievement. The MAAP 3.0B code and Latin Hypercube sampling technique are used to determine the uncertainty of the performance achievement parameter. Meanwhile, the value of the performance requirement parameter is obtained from interviews. Based on these stochastic obtained, human error probabilities are calculated with respect to the various means and variances of the things. It is shown that this method is very flexible in that it can be applied to any kind of the operator actions, including the actions associated with the implementation of accident management strategies.

• 대한교통학회지
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• 제31권6호
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• pp.12-21
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• 2013

관광지역 내 궤도교통수단 요금은 사업 타당성 판단의 중요한 변수가 되는 요소이다. 기존 운영자 위주의 요금 결정에서 벗어나, 이용자 측면까지 동시에 고려된 요금을 산출함으로써 운영자와 이용자를 동시에 만족시키는데 본 연구의 목적이 있다. 본 연구의 대상은 인천광역시 중구 월미도 일대를 순환하는 월미은하레일이다. 본 연구에서는 요금의 적정 범위를 판단하기 위해 운영자 비용과 이용자 비용을 최적화하는 모형을 구축하였다. 최적화된 모형을 활용하여 각 변수의 값을 산출한 결과, 정류장 간격은 0.532km, 운행 간격은 0.206시, 정류장 수는 12개소, 운행 대수는 3대로 도출되었다. 이렇게 도출된 변수들을 활용하여 이용자가 지불해야하는 최소요금과 운영자가 징수해야 하는 최소요금을 산출하고, 이를 근거로 요금의 적정범위를 분석한 결과 최소 1,261원에서 최대 5,063원인 것으로 분석되었다. 관광교통수단의 경우 정류장 자체가 관광지 내에 위치하므로 모형 적용시 접근거리 감소폭이 매우 적어 접근비용의 변화폭이 미미하다는 점을 확인할 수 있었다.

• 한국항행학회논문지
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• 제21권6호
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• pp.529-536
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• 2017

일반적인 지상통제 시스템은 단일 무인항공기 운용을 위한 통제 및 정보 전시 기능을 갖추고 있다. 현대에서는 단일 지상통제 시스템을 사용하여 복수 무인항공기의 운용이 요구되고 있다. 이로 인하여 무인기 운용자는 과거보다 다양한 임무 수행이 요구되며, 임무 수행 중 다양한 요인에 의하여 임무과부하를 받게 된다. 본 연구에서는 복수무인기 운용자의 임무과부하 측정을 통해 운용자의 상태를 반영한 적응형 지상통제 시스템을 제안한다. 복수무인기를 운용할 수 있는 지상통제 소프트웨어를 개발하고, 또한 시뮬레이터를 구성하여 운용자가 지상통제 시스템의 운용을 통해 시스템의 기능을 검증한다. 적응형 지상체 실험을 분석한 결과, 비적응형 지상체 실험 결과와 대비하여 운용자의 동공지름이 감소하고, 임무 성능이 증가하는 등 적응형 지상체의 효용성을 확인하였다.

• 원예과학기술지
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• 제31권2호
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• pp.239-245
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• 2013

Occupational exposure and risk assessment were conducted to evaluate the safety of operators when insecticide acetamiprid was applied to apple orchard using a speed sprayer. Dermal patches, cotton gloves, socks, and masks were used to monitor the dermal exposure, and personal air pump with solid sorbent was used to measure the potential inhalation exposure. In validation to analytical methods, the limit of detection and limit of quantitation were 0.25 ng and 1 ng, respectively. Good reproducibility (coefficient variation < 4%), linearity (coefficient determination > 0.999), and recovery (85.3-118.2%) were obtained. Trapping efficiency of solid sorbent was 96.4% while breakthrough did not occur. Only hand exposure was measured on the gloves during mixing/loading to give $33-1,132{\mu}g$. Exposure amount of operator 3 among 4 workers was noticeably high. The total volumes of spray liquid for operators were $535-1,235mL{\cdot}h^{-1}$, corresponding to 0.03-0.08% of the applied spray solution. Highest contaminated parts of body were thighs, chest, and lower legs. The inhalation exposure ratio to the total application amount was significantly low. However, wind seemed to affect the inhalation exposure of operator. For risk assessment, margin of safety was calculated by the application of cloth and dermal penetration rate to obtain values of much larger than 1 in all cases. Therefore, health risk of operators during treatment of acetamiprid in apple orchard could be of least possibility.

• 한국위성정보통신학회논문지
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• 제12권4호
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• pp.50-55
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• 2017

본 논문에서 한국형 위성보정 시스템(KASS :Korea Augmentation Satellite System)을 구성하고 있는 위성통신국(KUS : KASS Uplink Station)의 RF시스템 감시제어장치에 대한 설계를 기술하였다. 한국형 위성보정 시스템은 KASS라 명명되어 APV-1급 SoL 서비스 수준의 SBAS 시스템 개발과 CAT-1급 시험운영 기술 개발을 목표로 한다. 위성통신국 RF 시스템의 감시제어장치에 대해 소프트웨어 및 하드웨어 개발 환경, 감시제어장치의 기능 및 알고리즘, 감시제어장치의 구조 및 사용자 인터페이스를 설계하였다. 감시제어장치 설계에 있어 이미 개발 활용되고 있는 통신해양기상위성 및 무궁화위성 5A/7호 관제시스템의 감시제어장치 설계를 활용하여 시스템의 안정도 및 신뢰성을 확보하였다. 또한 실제 운영자의 요구에 의한 사용자 인터페이스를 보다 편리하게 제공할 수 있도록 하였다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.808-811
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• 2006

The KOMPSAT-2 was developed by KARI and it was successfully launched from Plesetsk, Russia on 28th July 2006. The Korean government decided the commercialization of the KOMPSAT-2 image data and direct reception services worldwide. SPOT Image, based in Toulouse (France) was selected by KARI through an international open bidding as a foreign company for the KOMPSAT-2 image promotion over the entire world except the territory of Republic of Korea including the North Korea, the United States of America, UAE, Saudi Arabia, Kuwait, Qatar, Oman, Yemen, Egypt, Iran, Iraq, Jordan, Lebanon, and Syria. KAI (Korea Aerospace Industry Ltd.) is an engaged Korean company for this area. KARI has responsibility to operate the satellite, data acquisition, archiving for the worldwide commercialization. For the processing and delivery of the KOMPSAT-2 image data to the users of KAI and SPOT Image, KAI has the binding contract with KARI. So KAI has the responsibility for the commercial ground station operation such as user support, data processing, and the data delivery. The KOMPSAT-2 ground station is hosted in KARI, so KARI has developed the concept of KOCUST (KOMPSAT-2 Commercial User Support Team) jointly with KAI to support the data processing and delivery as KOMPSAT-2 developer and satellite operator. The main purpose of the KOCUST is to support the operational activities to provide the data and service quality to satisfy customers. KOCUST will be organized by the members of KARI and KAI together. KARI members will mainly take the role of KOCUST coordination, data processing and user support in a public sector. KAI members are going to take user desk, data validation and delivery et cetera, which are related with users. This paper describes a summarized concepts of KOCUST like organization, dedicated tasks of each part and work flow of daily operation.