• 한국안전학회지
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• 제37권4호
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• pp.28-35
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• 2022

This study is aimed to develop a safety diagnosis system for fire pumps that detects normal and abnormal signals for the stable operation of the system. Hence, the following activities were carried out: first, a threshold value was identified for the normal operation and six abnormal operations (adherence of impeller, absence of water source, separation of pump and motor, run-stop operation, air inflow into the casing, and reverse-phase loss of the power line) reflecting changes in the current, flow and pressure of fire pumps; secondly, based on the identified signals, an algorithm capable of detecting three abnormal signals was developed and in terms of hardware, a current, pressure and flow sensor suitable for the analogue input values of NI-6009 was designed and installed. This combination of the hardware and software is applicable as a diagnosis system to ensure the stable operation of fire pumps.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2004년도 춘계 학술대회논문집
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• pp.208-213
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• 2004

The HANARO, multi-purpose research reactor, 30 MWth open-tank-in- pool type, is under normal operation since it reached the initial critical in February 1995. The HANARO is planning to produce a fission moly-99 of radio isotopes, a mother nuclide of Tc-99m, a medical isotope and is under developing a target handling tool for loading and unloading it in a circular flow tube (OR-5). A guide tube is extended from the reactor core to the top of the reactor chimney for easily un/loading a target under the reactor normal operation. But active coolant through the core can be quickly raised up to the top of the chimney through the guide tube by jet flow. This paper is described an analytical analysis to calculate the hole size of a orifice inserted in the circular irradiation hole and to study the flow characteristics through the guide tube under reactor normal operation and loading the target. As results, the results show that the hole size of orifice was 31 mm of the inner diameter to suppress the guide tube jet flow and the coolant safely cooled the target of fission moly after inserting the orifice to the flow tube.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2004년도 춘계 학술대회논문집
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• pp.214-219
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• 2004

The HANARO, a multi-purpose research reactor of 30 MWth, open-tank-in-pool type, has been under normal operation since its initial criticality in February, 1995. The HANARO is composed of inlet plenum, grid plate, core channel with flow tubes and chimney. The reactor core channel is located at about twelve m (12 m) depth of the reactor pool and cold by the upward flow that the coolant enters the lower inlet of the plenum, rises up through the grid plate and the core channel and exit through the outlet of chimney. A guide tube is extended from the reactor core to the top of the reactor chimney for easily un/loading a target under the reactor normal operation. But active coolant through the core can be Quickly raised up to the top of the chimney through the guide tube by jet flow. This paper is described an analytical analysis to study the flow behavior through the guide tube under reactor normal operation and unloading the target. As results, it was conformed through the analysis results that the flow rate, about fourteen kilogram per second (14 kg/s) suppressed the guide tube jet and met the design cooling flow rate in a circular flow tube, and that the fission moly target cooling flow rate met the minimum flow rate to cool the target.

• 한국전산유체공학회지
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• 제10권2호
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• pp.1-6
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• 2005

The HANARO, a multi-purpose research reactor of 30 MWth, open-tank-in-pool type, has been under normal operation since its initial criticality in February, 1995. The HANARO is composed af inlet plenum, grid plate, core channel with flow tubes and chimney. The reactor core channel is located at about twelve meters (12 m) depth of the reactor pool and cooled by the upward flow that the coolant enters the lower inlet of the plenum, rises up through the grid plate and the core channel and comes out from the outlet of chimney. A fission moly guide tube is extended from the reactor core to the top of the reactor chimney for easily loading a fission moly target under the reactor normal operation. But active coolant through the core can be quickly raised up to the top of the chimney through the guide tube by jet flow. This paper describes an analytical analysis that is the study of the flow behavior through the guide tube under reactor normal operation and unloading the target. As results, it was conformed through the analysis results that the flow rate, reduced to about fourteen kilogram per second (14 kg/s) from the original flow rate of sixteen point three kilogram per second (16.3 kg/s) did not show the guide tube jet.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1835-1840
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• 2004

The HANARO, a multi-purpose research reactor of 30 MWth, open-tank-in-pool type, has been under normal operation since its initial criticality in February, 1995. The HANARO is composed of inlet plenum, grid plate, core channel with flow tubes and chimney. The reactor core channel is located at about twelve meters (12 m) depth of the reactor pool and cooled by the upward flow that the coolant enters the lower inlet of the plenum,. rises up through the grid plate and the core channel and comes out from the outlet of chimney. A guide tube is extended from the reactor core to the top of the reactor chimney for easily un/loading a target under the reactor normal operation. But active coolant through the core can be quickly raised up to the top of the chimney through the guide tube by a jet flow. This paper describes an analytical analysis that is the study of the flow behavior through the guide tube under reactor normal operation and unloading the target. As results, it was conformed through the analysis results that the guide jet is suppressed under the top of the chimney after modifying the orifice diameter of 37.5 mm to 31 mm.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제28권2호
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• pp.17-29
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• 2022

Purpose: In terms of efficiency and safety, this study attempted to organize data on the operation methods and architectural planning of infectious diseases hospitals. Methods: The results obtained through on-site and interview surveys with hospital officials and medical staffs at four infectious diseases hospitals under construction were summarized based on those original business plans and facility guidelines. Results: First, the operational methods to secure safety and operational efficiency were summarized for each department which are major hospital functions of infectious disease hospitals. Second, as the architectural planning, the characteristics of space and circulation of each department are summarized. For safety of medical staff, negative pressure and non-negative pressure zone have to completely separated. In addition medical staff wears PPE and enters the negative pressure zone and returns in the order of admiral, shower, and gowning in the PPE undressing room after patient treatment. In case of operational efficiency, flexible operation is required in normal and crisis situations. For example, it is important for The Ward to gradually switch to negative pressure beds in times of crisis from normal situation and the outpatient department considers the composition of negative pressure and non-negative pressure outpatient spaces that can operate in parallel even in crisis situations. Implications: Infectious disease hospitals require flexible operation and appropriate facilities for normal and crisis situations.

• 한국추진공학회지
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• 제25권5호
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• pp.1-9
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• 2021

국내 소형 가스터빈엔진 상용화 시장의 저변화를 위하여 상용 소형 가스터빈엔진의 시동 및 정상운용구간에서의 제어로직을 파악하고자 하였다. 이를 통하여 시동 및 정상운용구간에서 엔진의 점화 및 정상작동을 위하여 엔진의 점화기, 시동모터, 연료펌프 및 연료밸브가 어떻게 제어되는지 파악하였고, 확보된 제어로직을 실제 상용화 연구가 진행되고 있는 소형 가스터빈엔진의 지상용 제어기에 활용하였다. 해당 엔진은 비행용 엔진 제어기를 제작 중이며, 제작 완료 후 항우연에서 보유하고 있는 고도시험설비를 활용한 고도시험을 통해 비행시험 전에 고도에서의 운용성능을 확인할 예정이다.

• Journal of applied mathematics & informatics
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• 제33권5_6호
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• pp.545-557
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• 2015

A vague graph is a generalized structure of a fuzzy graph that gives more precision, flexibility and compatibility to a system when compared with systems that are designed using fuzzy graphs. In this paper, we define two new operation on vague graphs namely normal product and tensor product and study about the degree of a vertex in vague graphs which are obtained from two given vague graphs G₁ and G₂ using the operations cartesian product, composition, tensor product and normal product. These operations are highly utilized by computer science, geometry, algebra, number theory and operation research. In addition to the existing operations these properties will also be helpful to study large vague graph as a combination of small, vague graphs and to derive its properties from those of the smaller ones.

• 대한전기학회논문지
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• 제36권9호
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• pp.678-684
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• 1987

The identification problem of instrument faults in PWR pressurizer is considered. The instrument failure detection technique in this paper consists of two filters, a normal-mode Kalman filter which estimates plant states in normal operation and a bias estimator which estimates the magnitudes and directions of bias faults. The concept of threshold based on the residual of a Kalman filter in normal operation is introduced. The bias estimator is driven when the absolute value of residual exceeds the threshold. The suggested failure detection algorithm is applied to a PWR pressurizer. Computer simulations show that the prompt detection of bias fault can be performed very successfully when there exist instrument faults.

• Advances in Traditional Medicine
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• 제4권2호
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• pp.120-123
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• 2004

To test preschool children's medium- long distance stereoscopic vision normal average value, and intermittent strabismus children,s medium-long distance stereoscopic vision acuteness is the goal of this study. The software of random stereoscopic vision and graph, which is developed by Hu-Chong etc has been used, to test 414 cases normal preschool children and 19 cases intermittent exotropia childrens medium-long distance (1-5 m) stereoscopic vision (before operation and after operation). The normal average value of preschool children's medium-long distance stereoscopic vision was achieved. Intermittent exotropia children's stereoscopic vision acuteness was declined with the increase of distance. This method can provide reference as screening abnormal stereoscopic vision during scientific research and clinical work.