• Nuclear Engineering and Technology
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• v.28 no.3
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• pp.311-319
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• 1996

We reconstruct the assembly pinwise flux using several types of boundary conditions and confirm that the reconstructed fluxes are the same with the reference flux if the boundary condition is exact. We test EPRI-9R benchmark problem with four boundary conditions, such as Dirichlet boundary condition, Neumann boundary condition, homogeneous mixed boundary condition (albedo type), and inhomogeneous mixed boundary condition. We also test reconstruction of the pinwise flux from nodal values, specifically from the AFEN [1, 2] results. From the nodal flux distribution we obtain surface flux and surface current distributions, which can be used to construct various types of boundary conditions. The result show that the Neumann boundary condition cannot be used for iterative schemes because of its ill-conditioning problem and that the other three boundary conditions give similar accuracy. The Dirichlet boundary condition requires the shortest computing time. The inhomogeneous mixed boundary condition requires only slightly longer computing time than the Dirichlet boundary condition, so that it could also be an alternative. In contrast to the fixed-source type problem resulting from the Dirichlet, Neumann, inhomogeneous mixed boundary conditions, the homogeneous mixed boundary condition constitutes an eigenvalue problem and requires longest computing time among the three (Dirichlet, inhomogeneous mixed, homogeneous mixed) boundary condition problems.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.11
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• pp.24-34
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• 2019

An automotive automatic transmission is a popular power-transmitting device in passenger vehicles, as it provides various speed ratios for diverse driving conditions with easy manipulation and smooth gear shifting. The transmission is mainly composed of input and output shafts, planetary gear sets, brakes/clutches, and housing, and it yields multiple forward gears and one reverse gear by actuating the shifting devices of the brakes and clutches. In developing a new transmission, kinematic configurations of a transmission, which presents a brief structure and actuation schemes for speed ratios, need to be checked to determine if the structure can be assembled in a layout. It is impossible for a transmission concept having any interference in connecting main components to be developed further in the design process, since connection interference leads to failure of a layout design in the 2-D plane. In this research, an analysis of the assemblability of a front-wheel drive automatic transmission is carried out on an example concept design by applying the vertex addition algorithm based on graph theory.

• Journal of Distribution Science
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• v.20 no.9
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• pp.39-46
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• 2022

Purpose: At the industrial sites of aviation enterprises there is a significant optimization of the main production processes through the use of advanced digital technologies. The most promising are the latest technologies of industrial Internet of Things, active use of big data and practical application of artificial intelligence in production. Research design, data and methodology:The process of creating a competitive product in the high-tech aviation sector is actively linked to the investment appeal of aircraft and helicopter construction products, which is built on the basis of reducing production and time costs through the creation of an effective digital system. Results: The aviation cluster of Rostec State Corporation is currently being transformed in a significant way. The leading enterprises of the Russian aviation industry are actively mastering cooperation schemes using integrated digital management principles and the widespread introduction of digital products from leading Russian vendors. Conclusions: Following the transition to electronic aircraft design technologies and modern materials in the production of aircraft, UAC continues to improve all production processes through robotization and optimization of technological processes, due to the introduction of aircraft assembly technology in accordance with digital models.

• Journal of the HCI Society of Korea
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• v.2 no.2
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• pp.53-59
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• 2007

Several researches in 3D interaction have identified and extensively studied the four basic interaction tasks for 3D/VE applications, namely, navigation, selection, manipulation and system control. These interaction schemes in the real world or VE are generally suitable for interacting with small graspable objects. In some applications, it is important to duplicate real world behavior. For example, a training system for a manual assembly task and usability verification system benefits from a realistic system for object grasping and manipulation. However, it is not appropriate to instantly apply these interaction technologies to such applications, because the quality of simulated grasping and manipulation has been limited. Therefore, we introduce the intuitive and natural 3D interaction haptic interface supporting high-precision hand operations and realistic haptic feedback.

• Journal of Environmental Policy
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• v.7 no.3
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• pp.1-40
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• 2008

In this paper, I examine the welfare effects of various revenue-neutral tax reforms in the case of two vertically-related oligopolies(downstream and upstream), where the upstream industry is polluting. I show analytically when and how government can improve welfare by initiating various tax reforms, regardless of either the feasibility of a lump sum transfer or the availability of a tax on pollution. The profit wedge that is the difference between the unit price and the unit cost and the marginal environmental damages(MED) becomes important to decidethe direction of a tax reform and is crucial to determine the direction of welfare-improving tax-subsidy schemes. I also show that a tax on pollution(Pigouvian tax) is superior to a tax on intermediate good even in the case of vertically-related oligopolies, because the former always brings in positive welfare effect from the upstream firms' input substitutability, which a tax on intermediate good cannot provide. Some policy implications for 'reducing environmentally-harmful subsidies' are also discussed.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.3
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• pp.281-285
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• 2008

Eigenvalue reduction schemes approximate the lower eigenmodes that represent the global behavior of the structures. In the previous study, we proposed a two-level condensation scheme (TLCS) for the construction of a reduced system. And we have improved previous TLCS with combination of the iterated improved reduced system method (IIRS) to increase accuracy of the higher modes intermediate range. In this study, we apply previous improved TLCS to multi-level sub-structuring scheme. In the first step, the global system is recursively partitioned into a hierarchy of sub-domain. In second step, each uncoupled sub-domain is condensed by the improved TLCS. After assembly process of each reduced sub-eigenvalue problem, eigen-solution is calculated by Lanczos method (ARPACK). Finally, Numerical examples demonstrate performance of proposed method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.166-181
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• 2018

The aim of this review was to determine the status of acupuncture therapies in reducing obesity in obese patients and to determine the scheme and effectiveness of acupuncture therapies. Existing reports published between January 1, 2003 and December 31, 2017 in Kiss, Riss, National Assembly Library, Pubmed and CINAHL databases were searched electronically with the keywords obesity, acupuncture, auricular acupuncture, and electroacupuncture. After checking the original sources of the articles, 19 articles were included in the review. In a qualitative evaluation of the papers using a checklist from the Scottish Intercollegiate Guideline Network, one study scored 9 out of 10 points, 15 studies scored 7-8 out of 10 points, two studies scored 6 out of 10 points, and one study scored 3 out of 10 points. In the acupuncture therapy schemes, acupoints to reduce obesity included shemen, hunger, LI-11 (Quchi), LI-4 (Hegu), St-25 (Tianshu) and St-44 (Neiting). Acupuncture therapies were conducted for an average of 16.9 total sessions. In the studies that involved 20-day or 72-day duration for acupuncture therapies, the frequency of acupuncture therapies was 1 time/1-2 days. In the studies that involved 4- to 18-week duration for acupuncture therapies, the frequency of acupuncture therapies was 1-3 times/week. This study found acupuncture therapies were effective in reducing obesity, and acupuncture therapies reduced anthropometry, blood glucose and lipids and changed blood hormones. In the future, there is an urgent need for well-planned studies of the effectiveness of acupuncture therapies for reducing obesity in obese patients.