• 경영과정보연구
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• 제5권
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• pp.33-59
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• 2000

Problem definition is as important as problem solving in decision making. Decision makers, however, tend to see problem partly or to define it unclearly. The researchers on decision making tend to lay a focus only on the Process of solving the given problem. This dissertation empirically studied the Problem diagnosis and definition in the decision making process. This study developed three kinds of DSS(Decision Support System) for the research and analyzed the effectiveness of the problem diagnosis and definition using DSS developed in this study. The three kinds of DSS are K-T(Kennel and Tregoe) DSS which is a method of table-styled information Presentation, and F-N(Fact-Net) DSS and C-E(Cause and Effect) DSS which are methods of graphic-styled information presentation. The empirical study was conducted twice; the pilot test and the main test. The samples of experiment are 218 students for the pilot test and 259 students for the main test. The author used K-T DSS and F-N DSS for the pilot test, and the revised K-T DSS and C-E DSS for the main test. A questionnaire survey method was included in the main test process The result of the study shows that the group using DSS in problem diagnosis and definition is more effective than the group not using DSS. A table-styled information presentation DSS, K-T, turns out more effective than a graphic-styled information presentation DSS, F-N, K-T DSS and C-E DSS showed no significant differences in the effectiveness in the main test. These results indicate that the use of DSS in the stage of problem diagnosis and definition is very effective and the methods and types of system design are a significant factors for DSS development.

• 한국콘텐츠학회논문지
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• 제19권5호
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• pp.624-631
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• 2019

본 연구에서는 리프터의 점착력이 분말 처리된 지문에 미치는 영향에 대하여 알아보고자 하였다. 먼저 5종의 리프터의 점착력을 측정하는 실험을 수행하였다. 그런 다음 4종의 분말로 슬라이드 글라스에 유류된 지문을 현출하고 리프터로 전사한 뒤, 전사된 지문의 품질을 측정하였다. ASTM D3121-17 (Rolling ball tack test) 방법을 사용하여 리프터의 점착력을 측정한 결과, 젤라틴 리프터를 제외한 다른 리프터 간의 점착력 차이는 근소하였다. 또한, 전사된 지문의 품질은 리프터의 점착력과 유의한 관계가 없음을 확인하였다. 그러나 약한 점착력을 가진 젤라틴 리프터로 전사할 경우 전사된 지문의 품질이 좋지 않다면 추가적인 전사가 가능하다는 장점이 있다.

• 한국항행학회논문지
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• 제21권6호
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• pp.601-607
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• 2017

이 연구에서는 GNSS (global navigation satellite system) 인프라 기반 측위 보정정보 생성을 위한 전처리 단계인 GPS (global positioning system) 반송파 위상 측정치의 고장 검사를 수행하였다. 기존 CARST (carrier acceleration ramp step test) 방법은 수신기 시계 오차를 제거하기 위해 평균값을 이용함으로써 검사 대상에 영향을 준다. 따라서 이 연구에서는 차분 기법을 적용하여 기존 CARST 결과와 비교하였다. 실 데이터에 인위적인 고장을 인가하여 고장 시뮬레이션을 수행한 결과 차분 기법을 적용할 경우 각각의 위성에 대해 독립적인 고장 검출이 가능한 것으로 판단되었으며 단일차분과 이중차분은 유사한 결과를 나타내었다. 실 데이터를 이용하여 기존의 방법과 비교한 결과 위성 간 차분, 수신국간 차분 결과의 장단점을 확인할 수 있었다. 그러나 결과 값에 대한 위성 및 수신기 시계 오차의 영향은 추가적인 분석이 필요할 것으로 판단된다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 춘계학술발표회논문집(2)
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• pp.467-472
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• 1996

This study discusses special aspects of severe accident related recriticality modeling and analysis in the Advanced Neutron Source (ANS) reactor.$^{1, 2)}$ The analytical comparison of three elements core to former two elements case is conducted including evaluation of suitable nuclear cross-section sets to account for the effects of system configulation, fuel and moderator mixture temperature, material dispersion and the other thermal-hydraulics. Three elements core ANS reactor is the alternative core design which was proposed as a modified core design, with three fuel elements instead of two, that would allow operation with only 50% enriched uranium (former uranium fuel is the baseline design value of 93%) A comprehensive test matrix of calculations to evaluate the threat of a criticality event in the ANS is described. Strong dependencies still on geometry, material constituents, and thermal-hydraulic conditions are verified. Therefore, the concepts of mitigative design features are qualified.d.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2011년도 추계학술논문집 2부
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• pp.635-638
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• 2011

항공기 착륙 시 발생되는 높은 충격하중에서 승무원 및 기체를 보호하기 위해 높은 충격흡수율이 요구된다. 따라서 착륙 시 발생하는 충격을 효과적으로 흡수할 수 있는 착륙장치는 항공기 핵심 구성요소이다. 다양한 종류의 완충장치가 존재하나, 소형항공기 주착륙장치에는 판스프링 방식을 이용하여 충격에너지를 흡수할 수 있다. 착륙장치의 완충 성능은 반드시 낙하시험을 통해 입증하여야 하며, 이는 미 연방 항공 규정에서 요구하고 있는 사항이다. 이 논문에서는 소형항공기 낙하시험을 위한 설비, 시험 절차 및 낙하시험 수행 결과를 제시한다.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2011년도 추계학술논문집 2부
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• pp.631-634
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• 2011

항공기용 착륙장치의 완충기 충격흡수 성능은 해석 과정을 거쳐 예측한 값과 낙하시험을 수행하여 그 성능을 입증하여야 한다. 이는 미 연방 항공 규정에서 요구하고 있는 사항이다. 본 논문에서는 착륙장치 낙하시험을 위한 설비, 시험절차 및 시험방법과 낙하시험 수행 결과를 제시한다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.902-905
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• 2004

A heart diagnosis system adopts Superconducting Quantum Interface Device(SQUID) sensors for precision MCG signal acquisitions. Such system is composed of hundreds of sensors, requiring fast signal sampling and precise analog-digital conversions(ADC). Our development of hardware board, processing 64-channel 12-bit 1ks/s, is built by using 8-channel ADC chips, 8-bit microprocessors, SPI interfaces, and parallel data transfers between microprocessors to meet the 1ks/s, i.e. 1 ms speed. The test result shows that the signal acquisition is done in 168 usuc which is much shorter than the required 1 ms period. This hardware will be extended to 256 channel data acquisition to be used for the diagnosis system.

• International Journal of Railway
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• 제5권1호
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• pp.48-54
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• 2012

The main purpose of this study is to highlight the importance and validity of introduction of stress-concerned aptitude items for the safety critical workers, corresponding to the radical environmental change in railway industry. To attain this purpose, the author performed a brief literature survey, and scrutinized the western practice in detail. Then, the necessity of introduction of stress-related aptitude items was suggested, based on the statistics resulted from a survey which has been once performed for experts and drivers. The final conclusion is that the present selection system through which the safety critical workers are being staffed, without any rigorous screening mechanisms cannot but have some limitations. So, an overall restructuring for aptitude management system needs to be done in order for us to advance to the position of upper-class railway country.

• 설비공학논문집
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• 제2권3호
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• pp.208-217
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• 1990

A rectangular test section is devised by assuming two dimensional melting of a solid phase change material heated from two sides which are maintained at constant temperature and allowing a free expansion due to density difference between solid and liquid. The timewise melting shape is recorded photographically by the shadow graph method for several experimental conditions. The analysis shows that the melting process consists of four regimes. At first, the pure conduction heat transfer is dominant, and as time goes by natural convection grows and plays a role greatly. Experiments are carried out varying not only the wall temperature but height of the wall. Each effect of them on the melting process is obtained in the form of combination of dimensionless parameters, $Ste^{0.8}\;FoRa^{0.2}$. An algebraic correlation is suggested, which predicts the melted fraction well.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.404-408
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• 2009

Gas pipelines in bridges, roads and subway construction sections can undergo abrupt stress and vibration changes. To protect human life from any gas leakage accidents induced by the abrupt stress and vibration, the gas pipeline system needs to be continuously monitored. The estimation method of pipeline stress using MEMS wireless tilt sensor has been developed and its validity has been evaluated using a lab test bench.