• Nuclear Engineering and Technology
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• 제49권6호
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• pp.1240-1249
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• 2017

An essential component of the neutron transport solver is the resonance self-shielding calculation used to determine equivalence cross sections. The neutron transport code, MPACT, is currently using the subgroup self-shielding method, in which the method of characteristics (MOC) is used to solve purely absorbing fixed-source problems. Recent efforts incorporating multigroup kernels to the MOC solvers in MPACT have reduced runtime by roughly $2{\times}$. Applying the same concepts for self-shielding and developing a novel lumped parameter approach to MOC, substantial improvements have also been made to the self-shielding computational efficiency without sacrificing any accuracy. These new multigroup and lumped parameter capabilities have been demonstrated on two test cases: (1) a single lattice with quarter symmetry known as VERA (Virtual Environment for Reactor Applications) Progression Problem 2a and (2) a two-dimensional quarter-core slice known as Problem 5a-2D. From these cases, self-shielding computational time was reduced by roughly $3-4{\times}$, with a corresponding 15-20% increase in overall memory burden. An azimuthal angle sensitivity study also shows that only half as many angles are needed, yielding an additional speedup of $2{\times}$. In total, the improvements yield roughly a $7-8{\times}$ speedup. Given these performance benefits, these approaches have been adopted as the default in MPACT.

• Nuclear Engineering and Technology
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• 제45권6호
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• pp.803-810
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• 2013

The U.S. Department of Energy's Fuel Cycle Technologies R&D program under the Office of Nuclear Energy is working to advance technologies to enhance both the existing and future fuel cycles. One thrust area is in developing enabling technologies for next generation nuclear materials management under the Materials Protection, Accounting and Control Technologies (MPACT) Campaign where advanced instrumentation, analysis and assessment methods, and security approaches are being developed under a framework of Safeguards and Security by Design. An overview of the MPACT campaign's activities and recent accomplishments is presented along with future plans.

• ETRI Journal
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• 제9권1호
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• pp.165-172
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• 1987

본고에서는 컴퓨터의 출력장치로서 최근 가장 인기를 얻고 있는 논-임팩트 레이저 페이지 프린터(non-mpact laser page printer), 즉 레이저 빔 프린터(LBP : Laser Beam Printer)의 성능 및 특성에 관한 고찰과 현재 시판중인 desktop 레이저 빔 프린터를 비교 분석하고 그 응용사례에 대해서 간단히 소개하고자 한다.

• 농촌지도와개발
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• 제17권4호
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• pp.933-955
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• 2010

Researchers have different views on impact of information system use on productivity. The differences are fueled by 'the productivity paradox' insisted by Brynjofsson(1993). This paper intend to quantitate impacts of information system and to test the productivity paradox of using the information system. Restricted Maximumlikelihood Estimation(RMLE) method is applied on data from 81 farms adopting Pigplan system. The results find positive productivity improvement with information systems in swine farm. Adopting Pigplan system increases 0.52 in PSY(pigs per sow per year) and 0.087 in sow turnover. When it comes to region and farm size, region has impact on both PSY and sow turnover, while farm size does not. This result infers that local cooperatives, regardless of farm size, differentiate the impacts of the information system, implying that the ability to utilize information systems should be improved in organizational level.

• Nuclear Engineering and Technology
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• 제49권6호
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• pp.1326-1338
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• 2017

The continuous energy Monte Carlo neutron transport code, MC21, was coupled to the CTF subchannel thermal-hydraulics code using a combination of Consortium for Advanced Simulation of Light Water Reactors (CASL) tools and in-house Python scripts. An MC21/CTF solution for VERA Core Physics Benchmark Progression Problem 6 demonstrated good agreement with MC21/COBRA-IE and VERA solutions. The MC21/CTF solution for VERA Core Physics Benchmark Progression Problem 7, Watts Bar Unit 1 at beginning of cycle hot full power equilibrium xenon conditions, is the first published coupled Monte Carlo neutronics/subchannel T-H solution for this problem. MC21/CTF predicted a critical boron concentration of 854.5 ppm, yielding a critical eigenvalue of $0.99994{\pm}6.8E-6$ (95% confidence interval). Excellent agreement with a VERA solution of Problem 7 was also demonstrated for integral and local power and temperature parameters.

• 한국소음진동공학회논문집
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• 제14권10호
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• pp.945-954
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• 2004

Recently, specifications of flat display module is going to be higher definition, brightness and more wide viewing angle. On the other hand, physical thickness of those modules is forced to be slimmer and lighter. The flat display modules such as plasma or TFT-LCD employ thin crystallized panels that are normally weak to high level transient mechanical energy inputs. As a result, anti-shock performance is one of the most important design specifications of TFT-LCD modules. TFT-LCD module manufacturers and their customers like PC or TV makers perform a series of strict impact/drop test for the modules. However most of the large display module designs are generated based on engineer's own trial-error experiences. Those designs may result in disqualification from the drop/impact test during final product evaluation. A rigorous study on the impact failure of the displays is of course necessitated in order to avoid the problems. In this article, a systematic design evaluation is presented with combinations of FEM modeling and testing to support the optimal shock proof display design procedure.

• 산업진흥연구
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• 제9권2호
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• pp.197-205
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• 2024

본 연구는 2012년부터 2022년까지 중국 A주 상장회사 중에서 중오염기업을 표본으로 하여 기업의 ESG 성과가 채무불이행 위험에 미치는 영향을 분석하였다. 연구 결과는 좋은 ESG 성과가 기업의 채무불이행 위험을 효과적으로 감소시키는 것으로 나타났다. 추가 분석에서는 기업의 ESG 성과가 자금조달 제약의 영향을 완화시켜 채무불이행위험을 감소시키는 것을 보여주었다. 본 연구는 ESG 성과의 관점에서 채무불이행 위험의 영향 요인을 탐색하고, 기업의 ESG 성과가 경제적으로 미치는 영향에 대해 연구하여, 기업의 채무불이행 위험 예방에 대한 실증적 자료를 제공하였다.