• Nuclear Engineering and Technology
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• 제53권7호
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• pp.2151-2161
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• 2021

Nuclear data (ND) sensitivity and uncertainty (S/U) quantification in shielding applications is performed using deterministic and probabilistic approaches. In this paper the validation of the newly developed deterministic program package ASUSD (ADVANTG + SUSD3D) is presented. ASUSD was developed with the aim of automating the process of ND S/U while retaining the computational efficiency of the deterministic approach to ND S/U analysis. The paper includes a detailed description of each of the programs contained within ASUSD, the computational workflow and validation results. ASUSD was validated on two shielding benchmark experiments from the Shielding Integral Benchmark Archive and Database (SINBAD) - the fission relevant ASPIS Iron 88 experiment and the fusion relevant Frascati Neutron Generator (FNG) Helium Cooled Pebble Bed (HCPB) Test Blanket Module (TBM) mock-up experiment. The validation process was performed in two stages. Firstly, the Denovo discrete ordinates transport solver was validated as a standalone solver. Secondly, the ASUSD program package as a whole was validated as a ND S/U analysis tool. Both stages of the validation process yielded excellent results, with a maximum difference of 17% in final uncertainties due to ND between ASUSD and the stochastic ND S/U approach. Based on these results, ASUSD has proven to be a user friendly and computationally efficient tool for deterministic ND S/U analysis of shielding geometries.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권5호
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• pp.15-25
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• 2013

In this study, two kinds of soil-based proficiency testing materials (PTMs), NICE-012L and NICE-012R were prepared and certified for Benzen, Toluene, Etylbenzene and Xylene with evaluation of uncertainties. In order to analyse BTEX (Benzen Toluene Etylbenzene Xylene) for the candidate materials, GC/MS was used after pretreatment according to methods of soil analysis by Ministry of Environment. For the homogeneity test among bottles in terms of candidate materials, ISO 13528 and IUPAC Protocol were used and according to the result, both candidate materials showed sufficient homogeneity. Also, the stability test over the candidate materials was accessed according to the ISO Guide 35 by classifying short-term and long-term stability and the result showed that both candidate materials showed decent stability. The reference values of the two candidate materials depending on BTEX components were derived from the average of the 11 samples that were used for verification of the samples' homogeneity. Uncertainty of measurement was combined by uchar that was caused by a characteristic value, $u_{bb}$ that was caused by between-bottle homogeneity, and $u_{stab}$ that was caused by stability, and then combined uncertainty ($u_{PTM}$) was multiplied to the coverage factor (k) derived from the effective degree of freedom from each factor that leads to expanded uncertainty (U) in about 95% of confidence level. The proficiency testing materials developed through this study were supplied to National Institute of Environmental Research (NIER) and utilized as an external proficiency testing materials for evaluating analysis capacity of soil agencies with specialty in terms of soil analysis approved by Minister of Environment.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권11호
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• pp.622-627
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• 2002

The power comparison techniques have implemented power measurements, in which a power comparator is used to balance ac against a dc power obtained from known values. The developed power standard system using the comparison techniques consists of dc sources, ac source, control switches, resistive voltage dividers, resistive shunts and a power comparator. The total uncertainty of the power standard system was proved by analysis of the component instruments. Its expanded(k=2) uncertainty is evaluated to be less than 30 uW/VA at unit power factor and 42 uW/VA at power factor 0.5

• ETRI Journal
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• 제31권4호
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• pp.376-386
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• 2009

An active radio frequency identification (RFID) system has the advantages of a long identification distance and a good identification rate, overcoming passive RFID drawbacks. Therefore, interest in the development of active RFID systems has been gradually increasing in areas of harbor logistics and national defense. However, some identification failures between active RFID systems developed under the same standards have been reported, presumably due to a lack of development of accurate evaluation methods and test equipment. We present a realization of the hardware and software of an emulator to evaluate the standard conformance of an active RFID system in a fully anechoic chamber. The performance levels of the designed emulator are analyzed using Matlab/Simulink simulations, and the applicability of the emulator is verified by evaluating the standard conformance of a real active RFID tag. Finally, we propose a new evaluation method by incorporating a self-running test mode environment into the RFID tags to reduce testing time and increase testing accuracy. The application of the suggested method to actual tags improves measurement uncertainty by 0.56 dB over that obtained using existing methods.

• 한국항공우주학회지
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• 제30권5호
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• pp.118-126
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• 2002

한국항공우주연구원은 추력 3,000 lbf급 고공환경 시험설비인 Altitude Engine Test Facility(AETF)를 갖추고 소형 가스터빈엔진의 고공환경 성능시험에 활용하고 있다. AETF를 국제수준으로 발진시키기 위하여 측정정화도 및 신뢰도 향상을 위한 일련의 연구를 진행하고 있으며 측정불확도 개선을 위한 설비 개선이 일부 진행된 상태이다. 본 연구에서는 해면고도(sea level), 마하수(Mn) 0.3, 0.5, 0.7, 0.9일 때 단축(single spool) 터보제트 엔진에 대한 정상상태 성능시험을 수행하였고, 이를 성능 예측 프로그램(DECK)과 비교분석하였다. 가스터빈엔진의 주요 성능변수인 공기유량, 추력, 비연료소모율에 대하여 측정불확도를 분석하여 총기유랑은 0.791~0.914%, 순추력은 0.851~1.706%의 불확도를 나타내었고 연료 유량의 측정불확도는 1.372~7.348%, 비연료소모율의 측정불확도는 1.642~5.205%로 산정되었다. 또한 본 연구를 통하여 측정불확도 개선 방안이 확인되었다.

• 대한기계학회논문집A
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• 제40권3호
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• pp.281-288
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• 2016

복합재는 재료 불균질성에 의해 고속 충돌 시 방호성능 자료가 산포한다. 본 연구에서는 다수의 충돌시험으로 복합판재 잔류속도 산포를 확보하고 수치해석으로 예측하는 방법을 정립하였다. 먼저 10개의 동일 시편으로 인장시험을 수행하여 파단변형률 산포를 얻었다. 같은 재료로 제작된 4ply([0/90]s)와 8ply([0/90/0/90]s) GFRP(Glass Fiber Reinforced Plastic) 복합판재에 FSP(Fragment Simulating Projectile) 고속 충돌시험을 동일 조건에서 다수 수행하여 잔류속도 산포를 얻었다. 인장시험에서 얻어진 파단 변형률 분포를 이용하여 수치해석을 수행하였다. 충돌속도는 4ply와 8ply 각각 411.7m/s와 592.5m/s이다. 시험 결과와 비교하여 적절한 잔류속도의 산포를 예측할 수 있었다. 추가적으로 복합판재의 경우 Solid요소 대비 Layered Solid요소로 모델링하면 계산시간이 감소되었다.

• 대한지하수환경학회지
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• 제6권1호
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• pp.14-22
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• 1999

순간수위변화 및 양수 시험은 현장에서 대수층의 수리상수 추정을 위해 널리 사용되는 수리시험이다. 그런데 이런 수리시험을 수행하고 그 결과를 해석함에 있어서 다양한 오차 및 불확실성 요인이 있음에도 불구하고 이에 대한 심각한 고려가 많지 않았다. 본 연구에서는 양수 및 순간수위 변화시험을 다수의 동일 관정에서 반복 수행하고 그 결과를 다각적으로 검토함으로써 두 수리시험에 개입될 수 있는 오차 및 불확실성 요인을 분석하였다.

• 천문학회보
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• 제41권1호
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• pp.39.1-39.1
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• 2016

The cosmic distance can be precisely determined using a 'standard ruler' imprinted by primordial baryon acoustic oscillation (hereafter BAO) in the early Universe. The BAO at the targeted epoch is observed by analyzing galaxy clustering in redshift space (hereafter RSD) of which theoretical formulation is not yet fully understood, and thus makes this methodology unsatisfactory. The BAO analysis through full RSD modeling is contaminated by the systematic uncertainty due to a non--linear smearing effect such as non-linear corrections and uncertainty caused by random viral velocity of galaxies. However, BAO can be probed independently of RSD contamination using the BAO peak positions located in the 2D anisotropic correlation function. A new methodology is presented to measure peak positions, to test whether it is also contaminated by the same systematics in RSD, and to provide the radial and transverse cosmic distances determined by the 2D BAO peak positions. We find that in our model independent anisotropic clustering analysis we can obtain about 2% and 5% constraints on $D_A$ and $H^{-1}$ respectively with current BOSS data which is competitive with other analysis.

• 한국지반공학회지:지반
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• 제2권3호
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• pp.37-50
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• 1986

해양구조물은 토질특성, 파랑하중, 해석방법 등의 불확정성으로 인해 확률론적인 방법으로 신뢰 도해석을 하는 것이 바람직하다. 축토지반에 설치된 해양구조물의 기초설계에서 가장 큰 불확정성 은 비배수전단강도에 기인한다. 따라서 점토지반의 전단강도 산정에 영향을 끼치는 모든 불확정성 을 조사하여 안정해석에 적용한다. 또한 실내시험과 현장관입계험을 이용한 정토지반의 전단강도 산정방법의 불확정성을 조사하고 북해의 Statfjord B에 위치한 중력식 해양구조물의 활동에 대한 신뢰도해석에 각각 적용한다. 현장관입시험을 이용하여 비배수전단강도를 산정하여 구한 활동에 대한 파괴확률은 실내시험을 이용한 경우보다 크다. 현장관입시험을 이용한 비배수전단강도 산정방법에 큰 불확정성이 존재하는 경험적인 방법으로 결정된 Nk 값의 불확정성에 주로 기인한다.

• 생물정신의학
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• 제21권3호
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• pp.87-92
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• 2014

Objectives Risk taking has been implicated in the development of various psychiatric disorders. Previous studies have indicated that risk taking behavior is associated with high levels of impulsiveness. Risk taking entail uncertain situation that outcome probability is unknown. This study tested impulsivity, intolerance of uncertainty and risk taking behavior. Methods A total of 73 participants completed a test battery comprised of the UPPS-P scale as a psychometric measurement of five dimensions of impulsivity, Intolerance of Uncertainty Scale, and Balloon Analog Risk Task (BART) as a behavioral measure of risk taking. The Pearson correlation analysis was used. Results The sensation seeking factor was positively correlated with BART measure (r = 0.27, p = 0.02). Specifically, the relationship between sensation seeking and BART was significant in females. Conclusions Among the five factors of UPPS-P, only the sensation seeking factor predicts risk taking propensity.