• Nuclear Engineering and Technology
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• 제49권5호
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• pp.920-927
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• 2017

With ever-advancing computer technology, the Monte Carlo (MC) neutron transport calculation is expanding its application area to nuclear reactor transient analysis. Dynamic MC (DMC) neutron tracking for transient analysis requires efficient algorithms for delayed neutron generation, neutron population control, and initial condition modeling. In this paper, a new MC steady-state simulation method based on time-dependent MC neutron tracking is proposed for steady-state initial condition modeling; during this process, prompt neutron sources and delayed neutron precursors for the DMC transient simulation can easily be sampled. The DMC method, including the proposed time-dependent DMC steady-state simulation method, has been implemented in McCARD and applied for two-dimensional core kinetics problems in the time-dependent neutron transport benchmark C5G7-TD. The McCARD DMC calculation results show good agreement with results of a deterministic transport analysis code, nTRACER.

• Steel and Composite Structures
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• 제46권3호
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• pp.435-449
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• 2023

Time domain method and frequency domain method are commonly used in the current fatigue life calculation theory. The time domain method has complicated procedures and needs a large amount of calculation, while the frequency domain method has poor applicability to different materials and different spectrum, and improper selection of spectrum model will lead to large errors. Considering that artificial neural network has strong ability of nonlinear mapping and generalization, this paper applied this technique to random fatigue life prediction, and the effect of average stress was taken into account, thereby achieving more accurate prediction result of random fatigue life.

• 대한조선학회논문집
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• 제53권5호
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• pp.362-370
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• 2016

The weight estimation and calculation of FPSO topsides is first performed at the bidding stage of projects. At this time, it is difficult to estimate and calculate accurately the weight because most of items of FPSO are not apparently defined. Especially, in the case of the pipe rack module, its portion of the total weight and the range of weight variation are large due to special features of piping and electric equipment in the module. Thus, it is very important to estimate and calculate accurately its weight in the task of the weight estimation and calculation of FPSO topsides. In this study, the past data for the weight of the pipe rack module were collected and analyzed, the WBS (Work Breakdown Structure) for the pipe rack module was constructed, and primary variables and secondary variables for developing a weight estimation and calculation model were selected. That is, after analyzing the past data, the volume was selected as the primary variable and the regression analysis was performed based on the variable. Then, several secondary variables were selected and incorporated into a weight estimation and calculation model. At this time, the weight per discipline was assumed from ratios of the total weight. Finally, the weight of the pipe rack module was estimated and calculated by using the developed model. As a result, the deviation from the model was better than that (-20 % ~ 60 %) of other studies about the weight estimation and calculation of FPSO topsides. Thus, the validity and applicability of the weight estimation and calculation of the pipe rack could be checked.

• 한국지반신소재학회논문집
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• 제18권4호
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• pp.87-95
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• 2019

토공량 산출은 건설현장에서 최적 공사비 산정을 위한 데이터로 정확한 토공량은 토목 공사의 설계 단계에서 시공단계까지 고려되어야 하는 중요한 요소이다. 토공량 산출을 위해서는 정확한 지형 자료와 정밀한 토공 부피 계산이 필요하다. 본 논문에서는 짧은 시간에 정확한 지형 파악이 가능하고, 경제성 측면에서도 장점을 갖는 드론 측량 기술을 이용하여 고정밀 토공량 산출 시스템을 도출하였다. 시스템의 정확도 검증을 위해 현장 검증시험을 수행하였으며, 드론을 이용한 토공량 산출 결과와 GPS 측량 장비를 이용한 토공량을 비교·분석하였다. 또한, 새롭게 개발한 토공량 부피 계산 알고리즘을 기존 항공사진측량 소프트웨어(Pix4D) 계산 방식과 비교하여 정확도를 검증하였다.

• Radiation Oncology Journal
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• 제2권1호
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• pp.129-137
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• 1984

In brachytherapy, it is important to determine the positions of the radiation sources which are inserted into a patient and to estimate the dose resulting from the treatment. Calculation of the dose distribution throughout an implant is so laborious that it is rarely done by manual methods except for model cases. It is possible to calculate isodose distributions and tumor doses for individual patients by the use of a microcomputer. In this program, the dose rate and dose distributions are calculated by numerical integration of point source and the localization of radiation sources are obtained from two radiographs at right angles taken by a simulator developed for the treatment planning. By using microcomputer for brachytherapy, we obtained the result as following 1. Dose calculation and irradiation time for tumor could be calculated under one or five seconds after input data. 2. It was same value under$\pm2\%$ error between dose calculation by computer program and measurement dose. 3. It took about five minutes to reconstruct completely dose distribution for intracavitary irradiation. 4. Calculating by computer made remarkly reduction of dose errors compared with Quimby's calculation in interstitial radiation implantation. 5. It could calculate the biological isoffect dose for high and low dose rate activities.

• 인터넷정보학회논문지
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• 제6권2호
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• pp.85-97
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• 2005

1985년에 처음 등장했던 테트리스는 많은 시간이 지난 지금에도 많은 유저들에게 사랑 받는 게임이 되었다. 지금까지의 테트리스는 줄이 삭제 될 때마다 삭제된 줄의 수에 따라 점수를 주는 방식을 채용하였고, 연속 공격 등에 관해 가산점을 부여해주었다. 그러나 이러한 점수 산출방식은 너무 일정하고 단순한 패턴을 주었다. 본 논문에서는 기존의 점수 계산 방식과는 다른 단계별 점수 계산 방식을 통하여 새로운 테트리스 게임 시스템을 설계 및 구현하고자 한다. 즉, 이는 전에 삭제된 줄의 수와 현재 삭제된 줄의 수를 비교하여 기본 점수에 가산점을 부여하는 방식이다. 단계별 점수산출방식을 이용하여 기존의 테트리스에서 한층 더 진보된 테트리스의 전략적인 이용을 가능하게 해 줄 것이다.

• 조명전기설비학회논문지
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• 제25권6호
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• pp.57-67
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• 2011

Purpose of this study is to find the mitigation method of magnetic field by finite length multi-conductors such as indoor distribution lines and to be applicable to design of the distribution lines. For this purpose, exact formula about the components $B_x$, $B_y$, $B_z$ of magnetic field need in case of straight line-conductor with finite length forward any direction. In this study simple formula of the components were deduced and by using these formula magnetic fields for various models of line-configurations were calculated. And also a calculation method of induced currents in conductive shield was presented and using this method, programing of calculation is relatively easy and calculation time is short. The magnetic field after cancellation by these induced currents was calculated. All of calculations were performed by Matlab 7.0 programs. Through the calculation results it could be obtained followings for the mitigation of magnetic fields. The separation between conductors ought to be smaller than smaller as possible. In case of 3-phase, delta configuration is more effective than flat configuration. In case of 3-phase, unbalanced currents ought to be reduced as possible.. In case of more than two circuits of 3-phase, adequate locations of each phase-conductor such as rotating configuration of 3-phase conductors are more effective. The magnetic shielding effect of the conductive shielding sheet is very high.

• Nuclear Engineering and Technology
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• 제19권3호
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• pp.186-191
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• 1987

본 논문에서는, 임의의 계통신뢰도를 매우 단순화시킬 수 있는 직접 모의 방법을 제시하였다. 계통의 비가용도 측면에서, 본 방법은 고장수목을 하드웨어적으로 구성함으로서 계산과정을 단순화시킬 수 있었다. 계산도구로는 프랑스의 Laviron씨가 개발한 ESCAF을 사용하였다. 금번 연구에서는 PWR 발전소의 OP$\Delta$T St OT$\Delta$T 찬넬의 비가용도를 IEEE std. 500-1977의 제시된 자료를 근거로 치산하였으며, 그 값은 8.17576$\times$$10^{-9}$ 로 나타났다. 또한 계산시간은 25초 미만이었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권5호
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• pp.1649-1665
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• 2021

In view of the low accuracy of the traditional FunkSVD algorithm, and in order to improve the computational efficiency of the algorithm, this paper proposes a parallel algorithm of improved FunkSVD based on Spark (SP-FD). Using RMSProp algorithm to improve the traditional FunkSVD algorithm. The improved FunkSVD algorithm can not only solve the problem of decreased accuracy caused by iterative oscillations but also alleviate the impact of data sparseness on the accuracy of the algorithm, thereby achieving the effect of improving the accuracy of the algorithm. And using the Spark big data computing framework to realize the parallelization of the improved algorithm, to use RDD for iterative calculation, and to store calculation data in the iterative process in distributed memory to speed up the iteration. The Cartesian product operation in the improved FunkSVD algorithm is divided into blocks to realize parallel calculation, thereby improving the calculation speed of the algorithm. Experiments on three standard data sets in terms of accuracy, execution time, and speedup show that the SP-FD algorithm not only improves the recommendation accuracy, shortens the calculation interval compared to the traditional FunkSVD and several other algorithms but also shows good parallel performance in a cluster environment with multiple nodes. The analysis of experimental results shows that the SP-FD algorithm improves the accuracy and parallel computing capability of the algorithm, which is better than the traditional FunkSVD algorithm.

• Nuclear Engineering and Technology
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• 제52권12호
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• pp.2760-2770
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• 2020

A model for calculation of fuel temperature profile using binary gas mixture of Helium and Xenon for gap gas conductance is proposed here. In this model, the temperature profile of a fuel pencil from fuel centreline to fuel surface has been calculated by taking into account the dilution of Helium gas filled during fuel manufacturing due to accumulation of fission gas Xenon. In this model an explicit calculation of gap gas conductance of binary gas mixture of Helium and Xenon has been carried out. A computer code Fuel Characteristics Calculator (FCCAL) is developed for the model. The phenomena modelled by FCCAL takes into account heat conduction through the fuel pellet, heat transfer from pellet surface to the cladding through the gap gas and heat transfer from cladding to coolant. The binary noble gas mixture model used in FCCAL is an improvement over the parametric model of Lassmann and Pazdera. The results obtained from the code FCCAL is used for fuel temperature calculation in 3-D neutron diffusion solver for the coolant outlet temperature of the core at steady operation at full power. It is found that there is an improvement in calculation time without compromising accuracy with FCCAL.