• 한국산업정보학회논문지
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• 제18권2호
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• pp.41-46
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• 2013

유한체상의 곱셈기는 오류 제어 코드, 암호시스템 및 디지털 신호처리와 같은 여러 분야의 기본적인 구성 요소이다. 최근 다양한 유한체상의 곱셈기가 세미-시스톨릭 구조를 기반으로 제안되었다. 또한, 몽고메리 알고리즘은 효율적인 곱셈 연산 알고리즘으로 잘 알려져 있다. 본 논문은 유한체 상에서 다항식 표현을 사용하여 효율적인 몽고메리 곱셈 알고리즘을 유도하고 이를 기반으로 세미-시스톨릭 몽고메리 곱셈기를 제안한다. 제안한 곱셈기는 병렬 구조에 적합한 몽고메리 인자를 선택하였으며 전체 계산 구조를 두 부분으로 나누어 동시에 계산할 수 있다. 제안한 곱셈기는 기존의 곱셈기에 비해 시간 복잡도를 30%~50% 정도 줄임으로써 전체 시간 복잡도의 30% 정도를 줄였다.

• Nuclear Engineering and Technology
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• 제52권1호
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• pp.14-18
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• 2020

Korea Atomic Energy Research Institute (KAERI) has carried out various neutronics experiments in the commissioning stage of the Jordan Research and Training Reactor (JRTR), and this paper introduces the results of first criticality prediction and experiment for the JRTR. The Monte Carlo Code for Advanced Reactor Design and analysis (McCARD) with the ENDF/B-VII.0 nuclear library was used for prediction calculations in the process of the first criticality approach, which was performed to provide reference for the first criticality experiment. In the experiment, fuel loading was carried out by measuring the inverse multiplication factor (1/M) to predict the number of fuel assemblies at the first criticality, and the first critical was reached on April 25, 2016. Comparing the first criticality prediction and experiment, the calculated and measured CAR (Control Absorber Rod) heights for the first criticality were 575 mm and 570.5 mm, respectively, that is, the difference between the two results was approximately 5 mm. From this result, it was confirmed that JRTR manufacturing and various experiments had successfully progressed as designed.

• Nuclear Engineering and Technology
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• 제20권3호
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• pp.179-188
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• 1988

최근 개발된 유한차분법의 하나인 선형특성 (LC) 법을 절단오차의 분석을 통하여 계단형 차분 (SD)법, 다이아몬드형차분 (DD)법, 그리고 계단형특성 (SC) 법과 비교했다. 제시된 4가지 방법들이 선속 계산문제, 유효증배계수 계산문제, 그리고 임계평판 두께 계산문제에 적용되었으며, 그때 계산된 결과들은 몇몇의 절단오차 측정 기준들에 의해 평가되어졌다. 본 연구의 주요 결론으로, 모든 경우에 있어서 어느 정도 기대했던 바와 같이 선형특성법이 가장 우수하다는 것이 밝혀졌으며, 특히, 선형특성법은 유효증배계수와 임계평판두께 같은 적분 인자들을 정확하게 계산하는데, 이는 선형특성법이 다른 방법들에 비해 오차소거(Error Cancellation)작용이 효과적으로 일어나기 때문으로 밝혀졌다.

• 한국의류학회지
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• 제34권7호
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• pp.1111-1125
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• 2010

Study is a basic analysis of a future virtual clothing system based on a comparative analysis of all the shirring, using a 3-dimensional apparel cad system. Frilled skirts shirred at the lower hemline were the subject of this study for a comparison of expression and shape of shirring. It compared the silhouette and details expressed in virtual and real skirts made of woolen fabrics and polyester satin, with different widths (1.5, 2 and 2.5 widths). It was found that the virtual skirt could not express shirring as exquisitely as the real skirt due to fabric thickness and other fabric characteristics. In addition, the increase in widths caused the frill shape to deform badly. In the case of a virtual skirt made of polyester satin, the increased multiplication factor let the frill spread out sharply (unlike the real skirt). Simulated skirts of polyester satin and woolen spread out to the sides with the sidelines of their frills hanging down markedly (unlike the real cloths) when the frills changed from 1.5 widths to 2 widths. When it came to the virtual skirt, side-line from the hip down all the way short of frill contorted with the wrinkle multiplication factor of 2 and 2.5 widths. This phenomenon was more notable in polyester satin skirts than in woolen skirts.

• 센서학회지
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• 제23권3호
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• pp.197-201
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• 2014

TEPC (Tissue Equivalent Proportional Counter) was usually used for high LET radiation dosimetry. We developed a prototype TEPC for micro-dosimetry in the range of $0.2{\sim}300 keV/{\mu}m$. And, the simulated site diameter of the TEPC is $2{\mu}m$, of similar size to a cell nucleus. For purposes of characterization the response for high LET radiation of the TEPC has been investigated under 135MeV/u Carbon ions in HIMAC (Heavy Ion Medical Accelerator). We determined the gas multiplication factor and measured the lineal energy spectrum [yd(y)] of 135 MeV/u Carbon ions. The value of the gas multiplication factor was 315 at 700 V bias voltage. As a result of the experiment, we could more understand the performance of the TEPC for high LET (Linear Energy Transfer) radiation. And the procedure of high LET radiation dosimetry using TEPC is established.

• Nuclear Engineering and Technology
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• 제50권1호
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• pp.18-24
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• 2018

This study proposes a new method of analyzing the burnup credit in boiling water reactor spent fuel assemblies against various operating parameters. The operating parameters under investigation include fuel temperature, axial burnup profile, axial moderator density profile, and control blade usage. In particular, the effects of variations in one and two operating parameters on the curve of effective multiplication factor ($k_{eff}$) versus burnup (B) are, respectively, the so-called single and compound effects. All the calculations were performed using SCALE 6.1 together with the Evaluated Nuclear Data Files, part B (ENDF/B)-VII238-neutron energy group data library. Furthermore, two geometrical models were established based on the General Electric (GE)14 $10{\times}10$ boiling water reactor fuel assembly and the Generic Burnup-Credit (GBC)-68 storage cask. The results revealed that the curves of $k_{eff}$ versus B, due to single and compound effects, can be approximated using a first degree polynomial of B. However, the reactivity deviation (or changes of $k_{eff}$, ${\Delta}k$) in some compound effects was not a summation of the all ${\Delta}k$ resulting from the two associated single effects. This phenomenon is undesirable because it may to some extent affect the precise assessment of burnup credit. In this study, a general formula was thus proposed to express the curves of $k_{eff}$ versus B for both single and compound effects.

• Nuclear Engineering and Technology
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• 제46권3호
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• pp.407-412
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• 2014

In this research, we investigated the burnup characteristics and the conversion of fertile $^{232}Th$ into fissile $^{233}U$ in the core of a Sodium-Cooled Fast Reactor (SFR). The SFR fuel assemblies were designed for burning $^{232}Th$ fuel (fuel pin 1) and $^{233}U$ fuel (fuel pin 2) and include mixed minor actinide compositions. Monte Carlo simulations were performed using Serpent Code1.1.19 to compare with CRAM (Chebyshev Rational Approximation Method) and TTA (Transmutation Trajectory Analysis) method in the burnup calculation mode. The total heating power generated in the system was assumed to be 2000 MWth. During the reactor operation period of 600 days, the effective multiplication factor (keff) was between 0.964 and 0.954 and peaking factor is 1.88867.

• Nuclear Engineering and Technology
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• 제54권9호
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• pp.3488-3493
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• 2022

Accelerator driven subcritical systems have long been discussed as facilities which can be used for solving the nuclear waste problem. The physics of these systems is very different from conventional reactors and new techniques had to be developed for reactivity monitoring. One such technique is the Area Ratio Method which studies the response of a subcritical system upon insertion of a large number of neutron pulses. An issue associated with this technique is the spatial dependence of measured reactivity which is intrinsic to the sub criticality of the system since the reactor does not operate on the fundamental mode and measured reactivity depends on the detector position. This is generally addressed by defining Bell-Glasstone spatial correction factor. This factor upon multiplication with measured reactivity gives the correct reactivity which is independent of detector location. Monte Carlo Methods are used for evaluating these factors. This paper presents a complete three dimensional map of spatial correction factors for BRAHMMA subcritical system. In addition, the dataset obtained also helps in identifying detector locations where the correction factor is close to unity, thereby implying no correction if the detector is used at those locations.

• 전자공학회논문지CI
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• 제41권2호
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• pp.77-86
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• 2004

일반적으로 작은 구조의 신경 회로망은 좋은 일반화 성능을 나타내지만 원하는 학습 목표까지 학습하기가 어려운 경향이 있다. 반면에 큰 구조의 신경 회로망은 학습 데이터는 쉽게 배우지만 일반화 성능이 좋지 않은 경향이 있다. 따라서 좋은 일반화 성능을 얻기 위한 일반적인 방법은 학습이 되는 한도 내에서 최소 구조의 신경 회로망 즉 최적 구조 신경 회로망을 찾는 것이다. 본 논문에서는 가중치의 제곱과 뉴런 출력의 분산의 곱으로 정의되는 임팩트 팩터(ImF: Impact Factor)를 이용한 새로운 연결 소거 알고리즘을 제안한다. 그리고 함수 근사화 문제에 적용하여 제안된 방법이 효율적임을 보인다.

• 한국약용작물학회지
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• 제1권1호
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• pp.38-42
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• 1993

양하(襄荷)를 대양번식(大量繁植) 하고자 경정부위(莖頂部位)의 기내배양(器內培養) 방법(方法)을 확립(確立)하기위하여, 경정부위(莖頂部位)의 생장(生長)에 알맞은 기본부지(基本部地) 및 식물생장조절제(植物生長調節劑)의 농도(濃度)를 구명(究明)하고자 본(本) 실험(實驗)을 수행(遂行)하였던 바 그 결과(結果)를 요약(要約)하면 다음과 같다. 1. 양하(襄荷)의 경정부위(莖頂部位)는 치상후(置床後) $10{\sim}12주(週)$ 후(後)에 기관(器官) 분화현상(分化現像)이 나타나서 shoot와 root가 발생(發生)되었다 2. 양하(襄荷)의 경정(莖頂)은 MS기본부지(基本部地)에 치상(置床)한 환경(環境) 비교적(比較的) 생장(生長)이 잘 되었다. 3. 기내(器內)의 Plantlet의 생장(生長)은 식물생장조절제(植物生長調節劑) NAA 0.5ppm과 BA 5.0ppm의 혼합(混合) 첨가배지(添加培地)에서 좋은 경향(傾向)이었다.