• 방사선산업학회지
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• 제17권1호
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• pp.83-92
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• 2023

When assessing the risk of radioactive wastes transportation on land, computer codes such as RADTRAN and RISKIND are used as deterministic methods. Transportation risk assessment using the deterministic method requires a relatively short assessment time. On the other hand, transportation risk assessment using the probabilistic method requires a relatively long assessment time, but produces more reliable results. Therefore, a study is needed to evaluate the exposure dose using a deterministic method that can be evaluated relatively quickly, and to compare and analyze the exposure dose result using a probabilistic method. The purpose of this study is to evaluate the exposure dose during transportation of radioactive wastes using deterministic and probabilistic methods, and to compare and analyze them. For this purpose, the main exposure factors were selected and various exposure situations were set. The distance between the radioactive waste and the receptor, the size of the package, and the speed of vehicle were selected as the main exposure factors. The exposure situation was largely divided into when the radioactive wastes were stationary and when they were passing. And the dose (rate) model of the deterministic overland transportation risk assessment computer code was analyzed. Finally, the deterministic method of the RADTRAN computer code and the RISKIND computer code and the probabilistic method of the MCNP 6 computer code were used to evaluate the exposure dose in various exposure situations during transportation of radioactive wastes. Then we compared and analyzed them. As a result of the evaluation, the tendency of the exposure dose (rate) was similar when the radioactive wastes were stationary and passing. For the same situation, the evaluation results of the RADTRAN computer code were generally more conservative than the results of the RISKIND computer code and the MCNP 6 computer code. The evaluation results of the RISKIND computer code and the MCNP 6 computer code were relatively similar. The results of this study are expected to be used as basic data for establishing the radioactive wastes transportation risk assessment system in Korea in the future.

• 한국화재소방학회논문지
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• 제18권1호
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• pp.42-48
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• 2004

다중이용시설의 화재 시 온도분포 및 연기유동 모델링은 결정론적 모델(Deterministic Model)인 존모델 (Zone Model)과 필드모델(Field Model)이 주로 사용되고 있다. 존모델은 공간을 두개의 지역으로 구분하여 화재현상을 분석하고, 필드모델은 공간을 다수의 Cell로 구분하여 분석하고 있으나 두 모델의 비교치에 대해서는 효용성 검증에 어려움을 겪고 있다. 따라서 화재현상의 모델링에 따른 수치적 이해와 관련자료의 검증을 통하여 실 상황에 보다 근접한 새로운 모델의 개발이 요구된다. 본 논문에서는 두 모델을 복합상영관의 실내공간에 적용하여 그 효용성을 분석해본 결과 공간 평균분포도에서는 존모델이, 세부적 공간현상에서는 필드모델의 적용이 적절한 것으로 판단된다. 또한 구체적인 화재의 성상과 감지기의 위치선정, 연기제어를 위한 제연설비의 검토를 위해서는 필드모델의 활용이 더욱 효과적이다.

• Management Science and Financial Engineering
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• 제18권1호
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• pp.21-26
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• 2012

Two previous studies that attempted to generalize the deterministic joint pricing-inventory decision model are reevaluated. We prove analytically that even in a single-product environment, the EOQ model with constant priceelastic demand cannot find optimal solutions unless two optimality conditions associated with price elasticity and demand magnitude are satisfied. Due to the inexistence of the general optimality for the problem, demand function and price elasticity must be evaluated and bounded properly to use the methods proposed in the previous studies.

• 한국경영과학회지
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• 제9권2호
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• pp.15-22
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• 1984

A deterministic multiproduct, facility-in series multiperiod production planning model is analyzed, where each period demand for the product of a facility appear in a fixed proportion of that for the product of the immediately following facility. The model considers concave production and inventory costs, which can depend upon the production in different facilities. No backlogging is allowed. It is shown that the model is represented via a single source network, which facilitates development of efficient dynamic programming algorithms for computing the optimal production schedule.

• 산업경영시스템학회지
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• 제18권36호
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• pp.93-103
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• 1995

This paper des with an economic production quantity model with partial backorders for the situation in which production lead time is deterministic and demand during lead time follows a continuous distribution. In the model, an objective function is formulated In minimize an average annual inventory cost. And then the procedure of iterative solution method for the model is developed to find both production reorder point and production quantity. Finally, sensitivity analysis for various partial backorder ratios and standard deviations of demand during production lead time are presented.

• 한국지진공학회논문집
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• 제11권4호
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• pp.25-31
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• 2007

For areas such as the Korean Peninsula, which have moderate seismic activity but no available records of strong ground motion, synthetic seismograms can be used to evaluate ground motion without waiting for a strong earthquake. Such seismograms represent the estimated ground motions expected from a set of possible earthquake scenarios. Local site effects are especially important in assessing the seismic hazard and possible ground motion scenarios for a specific fault. The earthquake source and rupture dynamics can be described as a two-step process of rupture initiation and front propagation controlled by a frictional sliding mechanism. The seismic wavefield propagates through heterogeneous geological media and finally undergoes near-surface modulations such as amplification or deamplification. This is a complex system in which various scales of physical phenomena are integrated. A unified approach incorporates multi-scale problems of dynamic rupture, radiated wave propagation, and site effects into an all-in-one model using a three-dimensional, fourth-order, staggered-grid, finite-difference method. The method explains strong ground motions as products of complex systems that can be modified according to a variety of fine-scale rupture scenarios and friction models. A series of such deterministic earthquake scenarios can shed light on the kind of damage that would result and where it would be located.

• 한국지능시스템학회논문지
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• 제11권6호
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• pp.505-509
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• 2001

본 연구에서는 학습기근을 갖는 결정론적 볼츠만 머신의 은닉충 뉴런에 비단조 활성화 함수를 적요한 경위의 학습성능을 XOR 문제와 ADD 학습에 대하여 수지 시뮬레이션을 통하여분석한다. 단조 활성화함수를 사용한 경우와 비교하여 학습 수렴률, 학습안정도, 및 학습 속도에 있어서 성능이 크게 향상됨을 확인하였다. 또한 네트워크의 막전위 분포를 조사함으로서 end-cut-off 타입의 비단조 함수를 이용한 경우에 나타는 다음 층의 뉴런에 영향을 주지 않는 뉴런의 출현, 즉, 신경회로망에 있어서 은닉층 뉴런늬 수을 자율적으로 조정하는것을 확인하였따. 이것은 학습문제에 대하여 네트워크 은닉층 뉴런의 수를 명확하게 결정할수 없는 현재의 상황에 있어서는 새로운 돌파구가 될것으로 기대된다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.181-186
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• 2003

There are many uncertainties in structural failures or structures, so probabilistic failure cause assessment should be performed in order to consider the uncertainties. However, in many cases of forensic engineering, the failure cause assessments are performed by deterministic approach though number of uncertainties are existed in the failures or structures. Thus, deterministic approach may have possibility for leading to unreasonable and unrealistic failure cause assessment due to ignorance of the uncertainties. Therefore, probabilistic approach is needed to complement the shortcoming of deterministic approach and to perform the more reasonable and realistic failure cause assessment. In this study, reliability-based failure cause assessment (reliability based forensic engineering) is performed, which can incorporate uncertainties in failures and structures. For more practical application, the modified ETA technique is proposed, which automatically generates the defected structural model, performs structural analysis and reliability analysis, and calculates the failure probabilities of the failure events and the occurrence probabilities of the failure scenarios. Also, for more precise reliability analysis, uncertainties are estimated more reasonably by using bayesian approach based on the experimental laboratory testing data in forensic report.

• 시스템엔지니어링학술지
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• 제19권2호
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• pp.46-58
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• 2023

Deterministic safety analysis is a crucial part of safety assessment, particularly when it comes to demonstrating the safety of nuclear power plant designs. The traditional approach to deterministic safety analysis models is to model the nuclear core using point kinetics. However, this simplified approach does not fully reflect the real core behavior with proper moderator and fuel reactivity feedbacks during the transient. The use of Multi-Physics approach allows more precise simulation reflecting the inherent three-dimensionality (3D) of the problem by representing the detailed 3D core, with instantaneous updates of feedback mechanisms due to changes of important reactivity parameters like fuel temperature coefficient (FTC) and moderator temperature coefficient (MTC). This paper addresses a CEA ejection accident at hot full power (HFP), in which the underlying strong and un-symmetric feedback between thermal-hydraulics and reactor kinetics exist. For this purpose, a multi-physics analysis tool has been selected with the nodal kinetics code, 3DKIN, implicitly coupled to the thermal-hydraulic code, RELAP5, for real-time communication and data exchange. This coupled approach enables high fidelity three-dimensional simulation and is therefore especially relevant to reactivity initiated accident (RIA) scenarios and power distribution anomalies with strong feedback mechanisms and/or un-symmetrical characteristics as in the CEA ejection accident. The Systems Engineering approach is employed to provide guidance in developing the work in a systematic and efficient fashion.

• 전자공학회논문지CI
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• 제48권3호
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• pp.76-81
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• 2011

침입방지시스템은 내부 시스템 보안 또는 외부 공격의 문제를 해결하기 위한 중요한 솔루션이다. 이러한 침입방지시스템을 도입 시 가장 우선적으로 고려해야 될 사항으로는 다양한 기능보다 안정성이다. 본 논문은 침입방지시스템 보안모델의 사용자 인증기능에 대한 안정성 검증을 위하여 칼라 페트리 네트를 이용하였다. CPN은 분산되어있고, 동시 발생적이며, 결정적 또는 동기화 방식의 비결정적인 시스템들에 대하여 그래픽적인 모델링 언어로 표현이 가능하다. 이런 칼라 페트리 네트는 각 처리 단계에 대하여 모든 가능한 상태와 발생 그래프로 표현된다. 침입방지시스템 보안 모델의 안정성은 칼라 페트리 네트를 이용한 모든 상태표현과 발생그래프의 분석결과가 무한반복 혹은 교착상태가 없으므로 검증되었다.