• Journal of Internet Computing and Services
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• v.6 no.4
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• pp.21-35
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• 2005

Software product-lines is the software development paradigm to attain the rapid development of quality applications by customizing the reconfigurable components and composing them based on predefined software architectures. Recently various methodologies for the component-based product lines are proposed, but these don't provide the specific implementation techniques of the components in terms of variability resolution mechanism. In other hand, the several approaches to implement the component supporting the variabilities resolution are developed, but these don't define the systematic analysis and design method considering the variabilities from the initial phase. This paper proposes the integration of PLUS, the one of product line methodologies extending UML modeling, and component code generation technique in order to increase the efficiency of producing the specific product in the software product lines. In this paper, the component has the hierarchical architecture consisting of the implementation elements, and each implementation elements are implemented as XSLT scripts. The codes of the components are generated from the feature selection. Using the microwave oven product lines as case study, the development process for the reconfigurable components supporting the automatic variability resolution is described.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.7
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• pp.601-611
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• 2007

Most of mechanically jointed aircraft structures are always encountered the fretting damages on the contact surfaces between two jointed structural members or at the edges of fastener holes. The partial slip and contact stresses associated with fretting contact can lead to severe reduction in service lifetime of aircraft structures. Thus a critical need exists for predicting fretting crack initiation in mechanically jointed aircraft structures, which requires characterizing both the near-surface mechanics and intimate relationship with fretting parameters. In this point of view, a series of fretting fatigue specimen tests for 2024-T351 Al-alloy, have been conducted to validate a mechanics-based model for predicting fretting fatigue life. And included in this investigaion were elasto-plastic contact stress analyses using commercial FEA code to quantify the stress and strain fields in subsurface to evaluate the fretting fatigue crack initiation.

• Computational Structural Engineering
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• v.9 no.1
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• pp.33-45
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• 1996

A general stiffener element which includes transverse shear deformation is formulated using the p-version finite element method. Hierarchic C/sup o/-shape functions, derived from Integrals of Legendre polynomials, are used to define the assembled stiffness matrix of the stiffener with respect to the local reference frame is transformed to the plate reference system by applying the appropriate transformation matrices in order to insure compatibility of displacements at the junction of the stiffener and plate. The transformation matrices which account for the orientation and the eccentricity effects of the stiffener with respect to the plate reference axes are used to find local behavior at the junction of the stiffener and the relative contributions of the plate and stiffener to the strength of the composite system. The results obtained by the p-version finite element method are comared with the results in literatures, especially those by the h-version finite element analysis program, MICROFEAP-II.

• Korean Journal of Construction Engineering and Management
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• v.16 no.5
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• pp.12-20
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• 2015

Construction industry pays attention to modular construction recently which based on factory production not on labor intensive site production. Since modular construction has high time shortening effect and easiness of demolition and recycling, it has been applied to the temporary residential building. Domestic modular construction market are not activated yet, however, due to the high initial cost to realize modular construction. This study proposes demand-sensitized movable modular building in order to reduce the financial burden. The study compares between RC method building and Modular building which moves building when the demand falls off from Life-Cycle Cost's viewpoint. As a result of the economical evaluation, RC method achieved profits faster than Modular model, but Modular model's gross earnings during the life-cycle are much bigger than RC method. In other words, the result means that the market-sensitized movement of the modular building would be an economci choice in Life-Cycle Costing aspect.

• Journal of the Korea Society for Simulation
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• v.17 no.2
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• pp.1-12
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• 2008

The major components of an engine are the cylinder block, cylinder head, crankshaft, connecting rod, and camshaft, which are more popularly known as the 5 C's. Thus, the engine shop usually consists of six sub-lines, including five machining lines and one assembly line. The flow line is the typical concept of the layout when the engineer designs the engine shop. This paper introduces a simulation study regarding the new crankshaft machining line in a Korean automotive factory. The major factors for designing the machining line are considered, and their effects on the system performance are evaluated with a three-dimensional(3D) simulation model that is developed with $QUEST^{(R)}$. The initial layout is analyzed using the simulation model, and we suggest some ideas for improvement.

• The KIPS Transactions:PartD
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• v.13D no.7 s.110
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• pp.931-938
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• 2006

It is important to operate an education resources which could be integrated to an system. But most of existing education information system was not developed with standardization. It is need the core education asset and reusable education service to make a good education system. Consequently, it is needed to use Sharable Content Object Reference Model(SCORM) based contents managing in order to reuse the contents of education. And it needs assembling and producing method with reusable core asset of education system to develop the application program for education. In this thesis, we study the Teaching-Learning supporting system to support systematic education resources. Teaching-Learning support system is developed of educational domain assess through development process based on Model Driven Architecture(MDA) and core asset on each stage. Application program of education is developed using MDA automatic tool through analyzing and designing for contents storage which is based on contents meta model. We finally can develop the application software of education with low cost and high productivity by raising the reusability of education contents and by using the core asset to the whole development process.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.10
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• pp.97-104
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• 2003

This paper addresses EMC test results for the EQM Communications & Broadcasting Satellite(CBS) Ka-band Payload System. The aim of the EMC test is to verify that the payload system has no effect on the other system and is not affected by the external field. The compliance of EMC system requirements was verified by the analysis and measurement of the emission level from the payload system. The variation of performance by noise injection was measured to inspect the susceptibility of the payload system. The analysis and test results also showed that the electromagnetic interference has no serious effect on the overall payload system performance. It is confirmed that the EQM CBS Ka-band payload system can be operable in the space environment from the EMC performance's viewpoint. It is also obtained that better performance can be acquired by improving waveguide design and integration method.

• Archives of design research
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• v.16 no.1
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• pp.93-102
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• 2003

This thesis is a study for the standardization of the design of ginseng cultivating facility (also known as the sun off facility) for the improvement of farming environment. The core background of this study is to propose a basic study for introducing, for the first time, the modern ginseng cultivating facility that matches the position of korea as a main nation cultivating ginseng and to secure the production and quality value of Koryo Ginseng, which is a special world-level agricultural product of Korea, under the present WTO agricultural product open system. Right now, wood, rice straw, or vinyls, which are non-standardized or are for one-time use only are used. Therefore, as a concept of the design, 1 tried to revise the fact that these materials are being used to set up the facility repeatedly every year which is creating environmental pollution and wasting of our countries labor and resource. Concrete factors to be improved are as follows: First, standardization of the form and structure of mass production system; Second, introduction of new materials such as semi-permanent resin etc., for standardization of materials; 1 tried to make the above two factors into a shape based on a Korean image. As for the design, designed a standard unit model of the ginseng cultivation facility especially keeping in mind to design it so the facility can be freely connected and assembled according to the size and shape of the cultivation area.

• Journal of KIISE
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• v.43 no.2
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• pp.246-255
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• 2016

The orthogonal frequency-division multiple access (OFDMA) systems are well suited to multi-rate multicast transmission, as they allow flexible resource allocation across both frequency and time, and provide adaptive modulation and coding schemes. Unlike layered video coding, the multiple description coding (MDC) enables flexible decomposition of the raw video stream into two or more substreams. The quality of the video stream is expected to be roughly proportional to data rate sustained by the receiver. This paper describes a mathematical model of resource allocation and throughput in the multi-rate video multicast for the OFDMA wireless and mobile networks. The impact on mean opinion score (MOS), as a measurement of user-perceived quality (by employing a variety of scheduling disciplines) is discussed in terms of utility maximization and proportional fairness. We propose a pruning algorithm to ensure a minimum video quality even for a subset of users at the resource limitation, and show the optimal number of substreams and their rates can sustain.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.410-415
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• 2001

Earned Value Management System(EVMS) has been considered as a useful tool of managing construction projects lately and its instruction into a private industry is now under consideration by the Korean government. It is on the basis of C/SCSC that had been released by the U.S. Department of Defense(DOD) since 1967. Its research has been in the active progress in order to utilize the earned value concept as a project management tool for construction project ordered by both government and private sector. Material Requirement Planning(MRP) is also known as a tool of planning and scheduling resources for assembly product as a part of inventory control models in the manufacturing industry. The purpose of this study is the effective employment of Earned Value Management to manage the construction projects by utilizing Material Requirement Planning(MRP), based on project management software and Workpackaging model.