• Journal of Korea Port Economic Association
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• v.20 no.1
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• pp.95-122
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• 2004

This study focuses on analyzing the potentiality of economic integration and the changes in logistics circumstances in Northeast Asia. So far as the changes in logistics circumstances in it, it is emphasized a complex transport system by sea and by land, according to the connection with the Railroad of South-North in Korean Peninsula and the Railroad of the Continent of Siberia. It first considers the propriety of economic integration among Korea, China and Japan in Northeast Asia. The first stage of the economic integration in Northeast Asia means it is started from contracting of FTA(Free Trade Agreement) which just agreed at the Summit Conference among Korea, China and Japan in ASEAN＋3(Korea China. Japan). At that time, the Summit Conference between the three countries have agreed to study on the propriety of FTA charging by own country's research organization. At first China has been hesitated to join with FTA in spite of high growth in his economy, because the time is not yet for it. After all, China also decided himself to participate to FTA together with Korea and Japan by reacted to the stimulus at the conference atmosphere between every country of ASEAN. The discussion on the changes in logistics circumstances also is needed to deal simultaneously with a situation in the economic integration in Northeast Asia. It is worthy to be paid our attention to the restoration of the Railroad of South-North in Korean Peninsula, which was disconnected for a long time from the dispute between South Korea and North Korea. Therefore, it needs to be investigated together with the movement of economic integration in Northeast Asia. The reaction on the restoration of the Railroad of South-North in Korean Peninsula is not only limited to the transport of trade cargo between South Korea and North Korea, but also it is reached to all of Northeast Asia, so far as to all of the area of Russia, Europe, and the other neighbor countries. Because this railroad is connected with the Railroad of the Continent of Siberia. The transport of trade cargo in Northeast Asia have been mostly depended upon the transport by sea until now. However, it would be divided into the transport by sea as well as by land from now. As its economic effect, the restoration of the Railroad of South-North in Korean Peninsula could be not only contributed to reduce the cost of logistics within South Korea and North Korea, but also within or without in Northeast Asia, Russia, and Europe. Consequently, it could be improved the power of international competitiveness of goods in Northeast Asia, according to the formation of a complex transport system together with the transport by sea and by land.

• Journal of information and communication convergence engineering
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• v.7 no.1
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• pp.19-23
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• 2009

In this paper, we propose a general idea about an RFID system which provides lighted weight algorithm. We discuss how RFID could be applied for this kind of system, especially, compact protocol. We evaluate a few protocols that have been suggested for use in passive RFID tagged systems. We can reduce security computation without losing security features by message integration and pre-computation in this paper. And the proposed protocol can be used in low-cost RFID systems that require a small computational load for both the back-end database and the tags.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.559-564
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• 1993

Nonlinear equation of motion of the flexible manipulator are derived by the Lagrangian method in symbolic form to better understand the structure of the dynamic model. The resulting equations of motion have a structure which is useful to reduce the number of terms calculated, to check correctness, or to extend the model to high order. A manipulator with a flexible 4 bar link mechanism is a constrained system whose equations are sensitive to numerical integration error. This constrained system is solved using the null space matrix of the constraint Jacobian matrix. Singular value decomposition is a stable algorithm to find the null space matrix.

• Journal of Information Display
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• v.11 no.1
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• pp.21-23
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• 2010

A new level shifter using low-temperature polycrystalline silicon (poly-Si) thin-film transistors (TFTs) for low-power applications is proposed. The proposed level shifter uses a capacitive-coupling effect and can reduce the power consumption owing to its no-short-circuit current. Its power saving over the conventional level shifter is 72% for a 3.3 V input and a 10 V output.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1997.10a
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• pp.76-79
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• 1997

In this study, an elasto-plastic finite element code, ESFORM, was developed to analyze sheet stamping processes. A formulation of 4-node degenerated shell element was implemented in the code. Workpiece materials were assumed to have planar anisotropy, and governed by associated flow rule. Explicit time integration method was employed to save computation time and reduce the required computer memory. Penalty method was used to describe interface behavior between workpiece and rigid die. Deep drawing of square cup and front finder stamping processes were simulated by ESFORM>

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.3
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• pp.319-324
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• 2005

This paper reports the performance of Wind-PV(Photovoltaic) hybrid system. The output power of PV is affected by the environmental factors such as solar radiation and cell temperature. Also, the output power of wind system is generated with wind power. Integration of Wind and PV resources, which are generally complementary, usually reduce the capacity of the battery. This paper includes discussion on system reliability, power quality and effects of the randomness of the wind and the solar radiation on system design.

• Journal of Ubiquitous Convergence Technology
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• v.2 no.2
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• pp.78-87
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• 2008

Received signal strength indicator (RSSI) is used as one of the ranging techniques to locate dynamic sensor nodes in wireless sensor network. Before it can be used for position estimation, RSSI values must be converted to distances using path loss model. These distances among sensor nodes are combined using trilateration method to find position. This paper presents an idea which attempts to integrate both path loss model and trilateration as one algorithm without going through RSSI-distance conversion. This means it is not simply formulas combination but a whole new model was developed. Several advantages were found after integration: it is able to reduce processing load, and ensure that all values do not exceed the maximum range of 16-bit signed or unsigned numbers due to antilog operation in path loss model. The results also show that this method is able to reduce estimation error while inaccurate environmental parameters are used for RSSI-distance conversion.

• Structural Engineering and Mechanics
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• v.27 no.5
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• pp.609-623
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• 2007

The problem of a semi-infinite magneto-electro-elastically impermeable mode-III crack in a magneto-electro-elastic material is considered under the action of impact loads. For the case when a pair of concentrated anti-plane shear impacts, electric displacement and magnetic induction impacts are exerted symmetrically on the upper and lower surfaces of the crack, the magneto-electro-elastic field ahead of the crack tip is determined in explicit form. The dynamic intensity factors and dynamic energy density factor are obtained. The method adopted is to reduce the mixed initial-boundary value problem, by using the Laplace and Fourier transforms, into three simultaneous dual integral equations, one of which is converted into an Abel's integral equation and the others into a singular integral equation with Cauchy kernel. Based on the obtained fundamental solutions of point impact loads, the solutions of two kinds of different loading cases are evaluated by integration. For some particular cases, the present results reduce to the previous results.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.4B no.2
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• pp.80-85
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• 2004

This paper reports the performance of a CB (Circuit Breaker) and converter for the battery operated Wind-PV (Photovoltaic) system. For this purpose, a fluctuating reduction controller for an electric generation hybrid (wind+PV) system is suggested. The method operates a wind turbine, PV, CB, converter and battery. Integration of wind and PV sources, which are generally complementary, usually reduce the capacity of the battery. Also, CB controls the overvoltage of the generation system. The objective is to control the operation of the converter and the CB and reduce power fluctuation. This paper includes discussion on system performance, power quality, fluctuation and effect of the randomness of the wind.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.846-850
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• 1996

Today's product development requires simultaneous satisfaction of low cost, high quality and fast time to market. It is, however, difficult for product designers and engineers to achieve this goal due to too many requirements. This study shows integrated Computer Aided Engineering (CAE) approach can help to achieve such goal. CAE can not only support designers when decision needs to be made during concept design period but also provide evaluation of the designed parts and guidance to the best design of products during detail design period. Furthermore, integration with virtual prototyping concept can reduce number of actual prototyping and consequently reduce product development cost and time considerably. In order to demonstrate its possibility, example of washing machine development using CAE and its results are presented in this study.