• Fire Science and Engineering
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• v.19 no.2 s.58
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• pp.1-7
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• 2005

An accurate knowledge of the minimum oxygen concentration(MOC) is important in developing appropriate prevention and control measures in industrial fire protection. In this study, by using the literature data and RSM(response surface methodology), the new equations for predicting the MOC are proposed. The A.A.P.E.(average absolute percent error) and the A.A.D.(average absolute deviation) of the reported and the calculated MOC for hydrocarbons were $3.48\%\;and\;0.37\;vol\%$, respectively and the correlation coefficient was 0.919. The A.A.P.E and the A.A.D of the reported and the calculated MOC for halogenated hydrocarbons and hydrocarbons were $5.06\%$ and $0.59vo1\%$, and the correlation coefficient was 0.938. The values calculated by the proposed equations were in good agreement with the literature data. Therefore, it is expected that this proposed equations will support the use of the research for other flammable substances.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.5
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• pp.715-722
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• 1999

On a urea-molasses-straw (3:15:82, UMS) based diet, effect of graded levels of mustard oil cake (MOC) supplementation on the performances of native bulls has been studied. Four cannulated adult Bos indicus bulls of $415({\pm}44.6)kg$ live weight and 80 months old, were given daily either of 0, 200, 400 or 800 g of MOC in four periods in a $4{\times}4$ latin square design. Besides, each animal also received 200 g of each of molasses and wheat bran and a mineral mixture. For unit (1 g) increase in MOC intake, total DM intake increased by 0.8 g/d ($r^2=0.88$) but no change in the straw DM intake. With the increasing levels of MOC, crude protein (CP) digestibility increased exponentially with an asymptotic value of 72%. However, MOC level had no effect on the digestibilities of DM, OM and ADF. Similarly, rumen degradability of rice straw was also not affected by the level of dietary MOC, and mean straw DM degradabilities were 15, 21. 28, 37, 47 and 51% at 8, 16, 24, 48, 72 and 96 hours of incubation respectively. Microbial N yield per kg digestible organic matter apparently fermented in the rumen were 7.46, 8.77, 6.88 and 5.96 g respectively for 0, 200, 400 or 800 g of dietary MOC. For each gram increase in dietary MOC, N intake and N balance increased by 0.054 g/d ($r^2=0.998$) and $0.59mg\;N/kg\;W^{0.75}/d$ ($r^2=0.99$) respectively. Nitrogen balance was estimated to be attained at the N intakes of $246mg\;N/kg\;W^{0.75}/d$. Thus, on a UMS-based diet supplementation of MOC up to 800 g (10% of total intake) of the dietary intake had little or no effect on intake, digestibility, rumen parameters, and microbial N yield but slightly increased the N balance. However marginal response to MOC supplementation is probably due to the high degradability of MOC protein in the rumen. Thus, any substantial positive response of MOC supplementation on a UMS-based diet can probably be achieved by reducing its protein degradability in the rumen.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 1999.12a
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• pp.1-4
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• 1999

This study was performed to develop an information processing system for the sound conservation of soil and groundwater resources. The system contains the geographic information system, and the numerical model of groundwater flow and contamination. Numerical models (MODFLOW,MOC3D) and GIS (ArcView) were integrated for the construction of an integrated management system of subsurface environment. The developed system was applied to the management of three mineral water companies located in clean mountain area. The impact of pumping over the overall catchment basin was modeled using the developed system for the decision of future management criteria.

• Nuclear Engineering and Technology
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• v.56 no.8
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• pp.3255-3267
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• 2024

This paper presents a high-fidelity simulation of the Organization for Economic Co-operation and Development (OECD) Nuclear Energy Agency (NEA) 3D whole-core Watts Bar benchmark using the UNIST in-house STREAM3D (Steady State and Transient Reactor Analysis code with Method of Characteristics) neutronic code. The benchmark encompasses various whole-core exercises, including single physics problems, multiphysics simulations, and depletion problems. When comparing parameters during the zero-power physics tests, including ITC, DBW, CRW, and criticality tests, STREAM3D results indicate a strong agreement with the measured data and KENO-VI. The comparison with the MC21/CTF code in 3D HFP BOC condition demonstrated strong agreement, with only a 0.42% difference in the normalized radial power distribution, a 0.38 K difference in the RMS of the assembly coolant exit temperature, and a mere 4 ppm difference in CBC.

• Nuclear Engineering and Technology
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• v.49 no.6
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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.

• Journal of the Korean Institute of Gas
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• v.6 no.1 s.17
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• pp.1-9
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• 2002

This paper presents simple models for flow and the PIG dynamics when it passes through a $90^{\circ}$ curved section of pipeline. The simulation has been done with two different operational boundary conditions. The solution fur non-linear hyperbolic partial equations for flow is given by using MOC. The Runge-Kuta method is used to solve the initial condition equation fur flow and the PIG dynamics equation. The simulation results show that the proposed model and solution can be used fur estimating the PIG dynamics when the pig runs in the pipeline including curved section. In this paper, dynamic modeling and its analysis for the PIG flow through $90^{\circ}$ curved pipe with compressible and unsteady flow are studied. The PIG dynamics model is derived by using Lagrange equation under assumption that it passes through 3 different sections in the curved pipeline such that it moves into, inside and out of the curved section. The downstream and up stream flow dynamics including the curved sections are solved using MOC. The effectiveness of the derived mathematical models is estimated by simulation results fur a low pressure natural gas pipeline including downward and upward curved sections. The simulation results show that the proposed model and solution can be used for estimating the PIG dynamics when we pig the pipeline including curved section.

• Journal of Environmental Impact Assessment
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• v.10 no.2
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• pp.99-108
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• 2001

This study was performed to develop an information processing system for the sound conservation of soil and groundwater resources. The system contains numerical models and geographic information systems for underground flow and contamination. Multidimensional Finite Element Model for Subsurface Environment (MFEMSE) was invented to analyze underground flow and pollution problems of water and gas phases. Newly developed and conventional models (MODFLOW, MOC3D, MT3D, PMPATH, PEST, UCODE) were integrated with GIS (ArcView) for the construction of an integrated information management system of subsurface environment. This system was applied to the management of three mineral water companies located in clean high mountain basin. Desirable management criteria and operational strategies were suggested using this system. The system was constructed to be applied for the broad sense of decision supporting tools in related topics of this study, so that it can be used not only for the prevention regulations, but also for clean up projects.

• Journal of Technologic Dentistry
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• v.41 no.1
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• pp.21-27
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• 2019

Purpose: To evaluate 2D and 3D of occulsal, mesial-occlusal and mesial-occlusal-distal cavity of composite resin inlay. Methods: Abutment tooth 16, 36 of FDI system was selected for the study. Inlay prostheses classified as occlusal cavity (OC group), mesial-occlusal (MOC) and mesial-occlusal-distal cavity (MODC) were prepared using composite resin. Composite resin was injected with composite resin in prepared tooth cavity and then photopolymerized with UV light. Additional thermal polymerization was performed. Marginal gap of composite resin inlays were measured by digital microscope(x160) with silicone replica technique. The data was analyzed from statistical software for Kruskal-Wallis test (${\alpha}=0.05$). 3-dimensional analysis was analyzed through superimposition method. Results: The smallest 2D marginal fit measure of the three groups was $47.0{\pm}21.6{\mu}m$ in the MOC group. The largest 2D marginal was $69.1{\pm}33.8{\mu}m$ in the MODC group. In the trueness of the three groups, the most accurate figure was $14.4{\pm}2.3{\mu}m$ for the MODC group. In Precision, the most accurate figure was $14.5{\pm}4.3{\mu}m$ for the MODC group. Conclusion : In this study, 2D marginal fit of OC, MOC, and MODC cavities fabricated with composite resin was applicable to all clinical applications. In the 3D inner surface accuracy evaluation, the MODC group showed the accuracy results.

• Nuclear Engineering and Technology
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• v.53 no.1
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• pp.30-43
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• 2021

In the 2D/1D method, a global adjoint CMFD based on the generalized equivalence theory is built to synthesize the 2D radial MOC adjoint and 1D axial NEM adjoint calculation and also to accelerate the iteration convergence of 3D whole-core adjoint transport calculation. Even more important, an advanced yet accurate two-level (TL) CMFD acceleration technique is proposed, in which an equivalent one-group adjoint CMFD is established to accelerate the multi-group adjoint CMFD and then to accelerate the 3D whole-core adjoint transport calculation efficiently. Based on these method, a new code is developed to perform 3D adjoint neutron flux calculation. Then a set of VERA and C5G7 benchmark problems are chosen to verify the capability of the 3D adjoint calculations and the effectiveness of TL CMFD acceleration. The numerical results demonstrate that acceptable accuracy of 2D/1D adjoint calculations and superior acceleration of TL CMFD are achievable.

• Nuclear Engineering and Technology
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• v.44 no.2
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• pp.113-150
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• 2012

The point we made in this paper is that, although detailed and precise three-dimensional (3D) whole-core transport calculations may be obtained in the future with massively parallel computers, they would have an application to only some of the problems of the nuclear industry, more precisely those regarding multiphysics or for methodology validation or nuclear safety calculations. On the other hand, typical design reactor cycle calculations comprising many one-point core calculations can have very strict constraints in computing time and will not directly benefit from the advances in computations in large scale computers. Consequently, in this paper we review some of the deterministic 3D transport methods which in the very near future may have potential for industrial applications and, even with low-order approximations such as a low resolution in energy, might represent an advantage as compared with present industrial methodology, for which one of the main approximations is due to power reconstruction. These methods comprise the response-matrix method and methods based on the two-dimensional (2D) method of characteristics, such as the fusion method.