• Journal of electromagnetic engineering and science
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• v.6 no.4
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• pp.217-221
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• 2006

Multipactor-free S-band duplexer based on inter-digital cavity type filter is proposed and demonstrated by in-house mulitpactor test facility for satellite RF components. Multipactor sensitivity of designed duplexer is analyzed by checking it out the maximum field accumulated region inside duplexer and calculating the electric field intensities at each resonator using 3D EM simulation in order to restrict the minimum gap distance as 2.5 mm which handles 43.13 dBm RF input power. Multipactor threshold was finally detected at 44 dBm in experiment for pulse mode test. The developed multipactor test method is cost effective, simple structure and gives a good agreement compared with the previous high cost MP test methodologies.

• IE interfaces
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• v.18 no.3
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• pp.297-307
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• 2005

PCB assembly is a complicated and difficult process to optimize due to the necessity of simultaneous consideration of component’s rack assignment and board mounting sequencing. An efficient PCB assembly method is developed by using neighboring positioned identical components information as well as quantity and size of the components. It is found that same type of components are located closely each other by checking real PCBs and interviewing with PCB designers in practice. Better performance of the developed procedure is obtained along with more number of total components and more number of neighboring positioned identical components cases. Simulation models are developed using Visual C++ for performance evaluation purposes of the suggested heuristic.

• Transactions of The Korea Fluid Power Systems Society
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• v.8 no.3
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• pp.14-20
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• 2011

This study aims at aligning multiple wafers to reduce wafer handling time in wafer processes. We designed a multilevel structure for a prealigner which can handle multiple wafer simultaneously in a system. The system consists of gripping parts, kinematic parts, vacuum chucks, pneumatic units, hall sensors and a DSP controller. Aligning procedure has two steps: mechanical gripping and notch finding. In the first step, a wafer is aligned in XY directions using 4-point mechanical contact. The rotational error can be found by detecting a signal in a notch using hall sensors. A dual prealigner was designed for 300mm wafers and constructed for a performance test. The accuracy was monitored by checking the movement of a notch in a machine vision. The result shows that the dual prealigner has enough performance as commercial products.

• Transactions of Materials Processing
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• v.8 no.3
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• pp.237-244
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• 1999

The purpose of this research is for the development of a new type forging equipment. H.C.G.(Hyundai Continuous Grain-Flow), by using two virtual build-up tools, rigid viscoplastic FEM and downsized plasticine experiment. This forging method consists of only vertical pressuree. Therefore, high quality crankshafts can be forged with this method as it can maintain a continuous grain flow. The factors considered in the development of equipment are die geometry for flawless deformed shape, die reaction forces, stress/strain distributions and continuous material flow. We carried out several numerical simulations and downsized plasticine experiments for the proper design of the forging equipment. The validity of those simulation results is confirmed by checking with the actual test results. Based on these simulation results, the proper design of the H.C.G. forging equipment is enabled.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2008.04a
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• pp.241-244
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• 2008

This study focused on the checking of design guideline using concept of reference plane as a promoting tool in order to apply to practical affair in relation to material standardization in housing build. For this purpose, we above all defined the role of reference plane. After establishing structural type can correspond to planning module of building components and coordination condition, we did exemplicated the sub-detail of building components which be to detach according to design method using the concept of reference plane that be complexed with spacial territory and replace cycle of building component or material.

• Magazine of the Korean Society of Agricultural Engineers
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• v.37 no.3_4
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• pp.82-89
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• 1995

The efforts of formulation have been reviewed and the results of existing laboratory experiments are investigated in order to describe the contracted flow which occurs at the final closure of sea dike construction. The regional characteristics of contracted flow is analyzed by checking the drawdown curve, and Chezy's mean velocity equation is employed to estimate the discharge rate at the closure. Weir-type discharge equations are reviewed, which are derived from Bernoulli equation, and the problems of the equations are discussed. Chezy's mean velocity equation is considered to be widely and generally applicable, and the empirical factor introduced in Chezy's equation is named 'form drag factor' since it is primarily dependent on the form drag caused by the contraction of discharge area. Laboratory experiments were conducted mainly in order to investigate the variation of form drag factor against various parameters, and an empirical equation is developed for the estimation of form drag factor.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10b
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• pp.1079-1084
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• 2000

The apartment houses which were constructed in a large quantity are currently being deteriorated and the reuse of them is directly related to the economic and environmental problem of the nation. Therefore, this research approaches to structural planning other than to the materials and/or the repair for the reuse of these deteriorated buildings. The research suggests the structural planning technique which includes the idea for the reinforcement of the structure in a part to improve the structural efficiency by investigating the current condition which includes the structural type of the buildings, examining the plan for the improvement of the structural efficiency, establishing the model of the space reorganization associated to the capability changes for the scale, the use, and the facilities, and checking of the structural efficiency through the structural analysis for the building structure suggested to be replaced.

• Journal of the Korean Institute of Rural Architecture
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• v.12 no.4
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• pp.45-52
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• 2010

The study has effected checking the traditional Korean-style house condition in Farm village and the resident preference test in jeonnam area for examination propriety of development a traditional Korean-style house. Also, it was checked over the problem and improvement direction of new building the Korean style house. The resident wanted living in the traditional Korean-style house if it is compromised problem of living equipment and cost of building. First. Jeonnam area Korean style house must keep the 'ㅡ' type plan. Second, the plan must construct compact and effective plan with the main floored room as the center for prevention against an indiscreet plan space extend of outside. Third, it has must need suitable material and construction for applying traditional exterior with effect. Fourth, it has must need actualization plan for the cost of construction is 3,500,000/py for construction.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2002.03a
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• pp.189-196
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• 2002

As the quantity of transported goods increases, there is a lot of mechanical trouble with loading facilities. So it tremendously produces not only economic loss but also time loss. To reduce the loss from the trouble of leading facilities, it is necessary to analyse the distribution of the problem's occurrence and use the analyzed data to minimize the outbreak of trouble. So the data can be usefully used when designing or manufacturing and it also can be utilized for proper maintenance of operating equipment, frequency of inspection and repair, know-how of checking on equipment and purchasing of spare parts. And it is possible to minimize the loss if the propel maintenance is adapted

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.581-586
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• 2003

As a very important part in development of the protocol, verification and conformance test for protocol specification are complementary techniques that are used to increase the level of confidence in the system functions. as prescribed by their specifications. In this paper, we verify the safety and liveness properties of rail signal control protocol type 1 specified in LTS(Labeled Transition System) with model checking method, and experimentally prove that it is possible to check for the deadlock, livelock and rechability of the states and actions on LTS. We also propose a formal method on generation of conformance test cases using the concept of UIO sequences from verified protocol specification.