• International conference on construction engineering and project management
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• 2005.10a
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• pp.1187-1192
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• 2005

Approximately 25% of military establishments became superannuated to unable perform their function, and it influences on the environment by construction wastes and the waste of national budget, as there is no rational and objective standard even though old facilities have been replaced through modernization project. Therefore, it has been searched to introduce industrial building system that can cope with the new building-construction and transference for the improvement of existing military establishments. However, as there is no economical estimation standard for practical use, industrial building-construction is still remaining at the initial stage, and the study is insufficient too. So. in this study, I would like to develope LCC cost model for rational LCC comparative analysis between industrial construction system (Modular) and existing reinforced concrete structure and cage, and to evaluate economical efficiency through case analysis.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.4
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• pp.130-137
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• 2010

This paper analyzes the main factors affecting user selection of a small-sum electronic payment system using survey data of 396 users. Several findings emerge. First, users consider three pillars and eight factors in adopting a new system : system features(stability, security, and flexibility), transaction cost(payment commission and settlement period), and financial capability of provider(stability of financial structure, risk management capability, and funding capability). Second, the stability of the financial structure of the system provider is the most important factor to user acceptance of a new e-payment system. Users tend to consider uncertainty risk more seriously than transaction cost. This reflects the reality that electronic payment system service industry has not fully fledged yet. Third, some moderating effects exist according to payment methods and business usages. As for payment methods, speedy settlement cycle for wired/wireless phone payment, system stability for credit card and account transfer payment, and security for advance payment means are crucial factors. As for business usages, the stability of financial structure for online game content, system stability for music and video content, proxy payment commission for e-learning content, flexibility of the payment system for digital adult content, and security for public services are decisive ones.

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.367-370
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• 2002

In this paper, we propose a new node architecture LonWorh control Network for home network system environmint using power line communications. Using conventional Lon Work technology is a many disputable points for home network. LonWork network system needs high-cost development equipment. Moreover, conventional Lon Work system can not implement high-grade algorithms and variety application operation. because of the limitation of processing ability in Neuron chip. For that reason, the proposed structure is applicable to low-cost and more complex applications which are impossible in home network using conventional Lonworks structure. The proposed structure is implemented with some hardware and かone software for power line home network. The physical layer and the MAC layer of the LonTalk protocol within ton Work are implemented in hardware, which decreases the development costs communication processor. The upper of link layer of the LonTalk protocol is implemented with software, which decreases the development costs of software and increases the flexibility of tile system and increases the extension of the system. We verified the commercial feasibility of the proposed system through the power line tests with the existing LonWorks network in home network. As a result, it is concluded that the proposed architecture provides increasing flexibility and decreasing cost of the system.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.476-479
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• 2010

In recent years, the deterioration of infrastructures is especially considered. In prestress concrete bridges, one of the important mechanisms of deterioration is the corrosion of the post-tensioned tendon due to environmental agents. In this study, the reliability analysis is performed for a prestress concrete box girder bridge under the pitting corrosion attack with considering the inspection and failure cost. The variation of life-time performance depending on inspection methods have to be quantified. The inspection methods with different accuracy of corrosion detection are presented and applied for model of reliability analysis. The computer program for analysis reliability index of the structure as well as updating process is obtained. An existing bridge is applied for illustrating the influence of inspection cost on the behaviors of structure. Subsequently, the benefit of inspection has shown to predict the time to failure of structure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.191-194
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• 1999

Recently, with the rapid development and demand for compactness of portable communications, the requirement for compact and low-cost filter is increasing. One of the methods for reducing size and cost is to use high dielectric constant and low loss dielectric material in filter. The other is new monoblock dielectric band-pass filter (BPF) which has holes in a single dielectric body without additional coupling elements. This structure effectively reduces the size and cost of the filters. For previous conventional coaxial type dielectric BPF, dielectric substrates were used for coupling between adjacent resonators and additional input and output ports were needed. Coupling between adjacent resonators of monoblock BPF can be otained via electrode pairs. Capacitances of electrode pair structure for coupling are intensively investigated by 3-D FEM. The BPF for PCS has been designed to have a 30 MHz pass-bandwidth with center frequency of 1855 MHz and an attenuation pole at below the passband using a commercial 3-D structure simulator.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.228-231
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• 2006

This paper briefly introduces silicon based thin film solar cells: amorphous (a-Si:H), microcrystalline ${\mu}c-Si:H$ single junction and $a-Si:H/{\mu}c-Si:H$ tandem solar cells. The major difference of a-Si:H and ${\mu}c-Si:H$ cells comes from electro-optical properties of intrinsic Si-films (active layer) that absorb incident photon and generate electron-hole pairs. The a-Si:H film has energy band-gap (Eg) of 1.7-1.8eV and solar cells incorporating this wide Eg a-Si:H material as active layer commonly give high voltage and low current, when illuminated, compared to ${\mu}c-Si:H$ solar cells that employ low Eg (1.1eV) material. This Eg difference of two materials make possible tandem configuration in order to effectively use incident photon energy. The $a-Si:H/{\mu}c-Si:H$ tandem solar cells, therefore, have a great potential for low cost photovoltaic device by its various advantages such as low material cost by thin-film structure on low cost substrate instead of expensive c-Si wafer and high conversion efficiency by tandem structure. In this paper, the structure, process and operation properties of Si-based thin-film solar cells are discussed.

• Korean Management Science Review
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• v.8 no.1
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• pp.41-50
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• 1991

Within the current construction industry, constractor equipment management practices lack structure and often are not addressed through an economic analysis and evaluation process. This paper explores two areas...cost of capital and inflation...with the intention of providing insight for a more structured and economic based approach to contractor equipment replacement practices rather than by the traditional "rule of thumb".umb".uot;.

• Korean Journal of Computational Design and Engineering
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• v.12 no.5
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• pp.376-381
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• 2007

The geometric configuration in the weight-reduced structure is very required to be started from the conceptual design with low cost, high performance and quality. In this point, a structural-topological shape concerned with conceptual design of structure is important. The method used in this paper combines three optimization techniques, where the shape and physical dimensions of the structure and material distribution are hierachically optimized, with the maximum rigidity of structure and lightweight.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.33 no.12
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• pp.11-18
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• 2017

The safety inspection cost of the construction work was based on commercial facilities classified as a single building. Therefore, it is not possible to fully reflect the characteristics of the multi-building construction project such as apartment houses. Therefore, this study suggests a reasonable estimation model that can fully reflect the characteristics of the multi-building construction project. The safety inspection cost estimation model proposed two models such as construction cost ratio method and cost plus fixed fee method. And these models were simulated by the apartment construction work and compared with the current standard. As a result, the current construction cost ratio method has shown that the safety inspection cost tends to be overestimated as the construction size increases. Therefore, the proposed model has reflected characteristics of the multi-building construction project, so that it can reasonably estimate the safety inspection cost more than the current standard.

• Journal of Digital Convergence
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• v.10 no.4
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• pp.181-190
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• 2012

Cost of capital is one of the key factors of accounting regulation policy for telecommunication market. This paper aims at investigating efficient policy improvements concerning accounting regulation for telecommunication market focused on cost of capital calculation methods and its application. At First, cost of capital estimating method should be improved. In estimating the cost of equity capital, it is necessary to use benchmark method for Equity risk premium. It will reduce analytical errors caused by a rapid economic change and inflation. It is also more desirable to use debt premium adding method for the cost of debt capital. Optimal capital structure method may be considered a better way to estimates capital structure. Secondly, cost of capital estimating process also has to be reformed. Telecommunication industry changes rapidly so it does not reflect fast environmental changes. Therefore, cost of capital should be calculated every year. Cost of capital should be calculated by individual companies. There is information asymmetry between regulators and regulatees. Because of that cost of capital calculating process takes long time and cost a lot. To solve this problem, regulator should legislate on cost of capital calculation and then regulating companies report the calculating result. Lastly, major telecommunication companies are all listed now and it is possible to calculating it separately. We must continuously improve the estimating method and application of cost of capital and due to the fast growing of telecommunication industry. The process of determining the calculating method must be discussed and best method chosen.