• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2000년도 춘계학술대회
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• pp.111-123
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• 2000

The recycling cell formation problem means that disposal products are classified into recycling part families using group technology in their end of life phase. Disposal products have the uncertainties of product status by usage influences. Recycling cells are formed considering design, process and usage attributes. In this paper, a novel approach to the design of cellular recycling system is proposed, which deals with the recycling cell formation and assignment of identical products concurrently. Fuzzy clustering algorithm and Fuzzy-ART neural network are applied to describe the states of disposal product with the membership functions and to make recycling cell formation. This approach leads to recycling and reuse of the materials, components, and subassemblies and can evaluate the value at each cell of disposal products. Application examples are illustrated by disposal refrigerators, compared fuzzy clustering with Fuzzy-ART neural network performance in cell formation.

• Journal of Contemporary Eastern Asia
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• 제11권1호
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• pp.21-29
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• 2012

The popularity of the Internet has affected international politics in many ways; however, it is seemingly overlooked by most scholars, and in particular, realists who view the Internet as low-politics. This article argues that the impact of the Internet on international politics should not be underestimated. By focusing on the capabilities of the Internet in general and P2P networks in particular, this paper shows how the Internet is able to disseminate soft power resources. This is demonstrated by an examination of the dissemination of Japanese soft power resources through BitTorrent. Finally, it is concluded that the Internet is a plausible agent for distributing the resources of soft power; however, once disseminated, soft power resources do not always transform into soft power. In the end, contextual conditions within states always apply.

• 대한족부족관절학회지
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• 제15권3호
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• pp.124-131
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• 2011

Ankle arthrodesis has been considered to be the standard operative treatment for end-stage ankle arthritis, nevertheless currently increasing arthroplasty. Indication for arthrodesis is painful ankle from global arthrosis regardless of the etiology. But it is hard to be carried out in the several circumstance such as infection states, poor vascularity, severe diabetes, prematurity, etc. So thorough evaluation should be done before the surgery, including adjacent joints status. The ideal position for fusion is neutral in flexion, functional valgus, and slightly external rotation. Methods of arthrodesis would be largely divided into two categories as in situ fixation and realignment procedure. The lateral and anterior longitudinal approaches are two common procedures, and fixation modalities are also variable. The long-term results of arthrodesis have been reported. Even the close follow-up have shown subsequent degeneration of adjacent joints, benefits such as reliable pain loss, easy correctability for deformity, and improved functional status with considerable durability can be expected in the most patients.

• International Journal of Control, Automation, and Systems
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• 제2권2호
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• pp.144-155
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• 2004

This paper addresses the issue of position control of a chain of multiple mass-spring-damper (CMMSD) units which can be found in many physical systems. The dynamic model of a CMMSD system with any degrees of freedom is expressed in a closed-form for the convenience of the controller design. Backstepping and model reference adaptive control (MRAC) approaches are then used to develop two adaptive output feedback controllers to control the position of a CMMSD system. The proposed controllers rely on the measurements of the input (force) and the output (position of the mass unit at the end of the chain) of the system without the knowledge of its parameters and internal states. Simulations are used to verify the effectiveness of the controllers

• 복식
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• 제42권
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• pp.25-42
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• 1999

This study aims to prove that the fact that minority races in the north-eastern region contributed sable skin to the Quing Dynasty might be related to Cho-Sun of King Muryong in the Warring states period because documents are available here and there. The Chinese had been using fur clothing since ancient times but we cannot find any mention that they had used sable skin. This fact shows that sable skin was not widely used because of its rarity. Cho-pi had been used in making costume on a large scale from the period of the Han Dynasty to the end of the Quing Dynasty. Cho-pi was very rare and it was used as a measure of bartering. China met the demand of cho-pi by the Cho-pi contributions of the frontier minority races. It might bwe that the high demand of Cho-pi in the Quing Dynasty forced minority races to contribute Cho-pi The documents concerning Cho-pi in the north-eastern region are of great importance not only to the history of costume but also to the history of ancient economy and national culture.

• Journal of Magnetics
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• 제16권3호
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• pp.201-205
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• 2011

We performed total energy and electronic structure calculations for the basic ground state properties of Fe using the conventional generalized gradient approximation (GGA) and screened hybrid functionals as the form of the exchange-correlation functional. To that end, we calculated structural (equilibrium lattice constants, bulk moduli, and cohesive energies) and electronic (magnetic moments and densities of states) properties. Both functional calculations gave the correct ground state, the ferromagnetic bcc phase, in which the structural parameters agreed well with experimental results. However, the description of the cohesive energies and magnetic moments at the ground state exhibited different behavior from each other: the unusually small cohesive energy and large magnetic moment were observed in the screened hybrid functional calculations compared to the GGA calculations. The reason for the difference was examined by analyzing the calculated electronic structures.

• Steel and Composite Structures
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• 제6권5호
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• pp.435-457
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• 2006

The paper presents the cost optimization of composite floor trusses composed from a reinforced concrete slab of constant depth and steel trusses consisting of hot rolled channel sections. The optimization was performed by the nonlinear programming approach, NLP. Accordingly, a NLP optimization model for composite floor trusses was developed. An accurate objective function of the manufacturing material, power and labour costs was proposed to be defined for the optimization. Alongside the costs, the objective function also considers the fabrication times, and the electrical power and material consumption. Composite trusses were optimized according to Eurocode 4 for the conditions of both the ultimate and the serviceability limit states. A numerical example of the optimization of the composite truss system presented at the end of the paper demonstrates the applicability of the proposed approach.

• Nuclear Engineering and Technology
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• 제49권1호
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• pp.29-42
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• 2017

The purpose of the present study is the presentation of the appropriate element and shape function in the solution of the neutron diffusion equation in two-dimensional (2D) geometries. To this end, the multigroup neutron diffusion equation is solved using the Galerkin finite element method in both rectangular and hexagonal reactor cores. The spatial discretization of the equation is performed using unstructured triangular and quadrilateral finite elements. Calculations are performed using both linear and quadratic approximations of shape function in the Galerkin finite element method, based on which results are compared. Using the power iteration method, the neutron flux distributions with the corresponding eigenvalue are obtained. The results are then validated against the valid results for IAEA-2D and BIBLIS-2D benchmark problems. To investigate the dependency of the results to the type and number of the elements, and shape function order, a sensitivity analysis of the calculations to the mentioned parameters is performed. It is shown that the triangular elements and second order of the shape function in each element give the best results in comparison to the other states.

• 대한전기학회논문지
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• 제41권5호
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• pp.562-572
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• 1992

In this paper, we propose software algorithms which provide acceleration/deceleration characteristics essential to high dynamic performance at the transient states where industrial robots or CNC machine tools start and stop. Software acceleration/deceleration methods are derived from the mathematical analyses of typical hardware systems controlling acceleration/deceleration. These methods make servo motors, which drive axes of motion, start and stop smoothly without vibration in the repeated tools. The path error, which is one of the most significant factors in the performance evaluation of industrial robots or CNC machine tools, is analyzed for linear, exponential, and parabolic acceleration/deceleration algorithms in case of circular interpolation. The analyses show that path error consists of the distance between the required path and generated one through acceleration/deceleration, and that between the generated one through acceleration/deceleration algorithm and the actual one of the end effector of the industrial robot or tool of the CNC equipment.

• Nuclear Engineering and Technology
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• 제50권2호
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• pp.306-312
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• 2018

There is an increasing need in the United States and around the world to move used nuclear fuel from wet storage in fuel pools to dry storage in casks stored at independent spent fuel storage installations or interim storage sites. Under normal conditions, the Nuclear Regulatory Commission limits cladding temperature to $400^{\circ}C$ for high-burnup (>45 GWd/mtU) fuel, with higher temperatures allowed for low-burnup fuel. An analysis was conducted with FRAPCON-4.0 on three modern fuel designs with three representative used nuclear fuel storage temperature profiles that peaked at $400^{\circ}C$. Results were representative of the majority of US light water reactor fuel. They conservatively showed that hoop stress remains below 90 MPa at the licensing temperature limit. Results also show that the limiting case for hoop stress may not be at the highest rod internal pressure in all cases but will be related to the axial temperature and oxidation profiles of the rods at the end of life and in storage.