• Journal of the Semiconductor & Display Technology
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• v.20 no.4
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• pp.38-43
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• 2021

Permanent magnet linear synchronous motor (PMLSM) is suitable for use in cleanroom environments and have advantages such as high speed, high thrust, and high precision. If the stators are arranged in the entire moving path of the mover, there is a problem in that the installation cost increases. To solve this problem, discontinuous armature arrangement PMLSM has been proposed. In this case, the mover receives a greater detent force in the section where the stator is not arranged. When a large detent force occurs, it appears as a ripple component of the thrust during PMLSM operation. If the shape of the stator is changed to reduce the detent force, the characteristics of the back EMF are changed. Therefore, in this paper, the detent force and the harmonic components of back EMF were reduced through multi-purpose shape optimization. To this end, the FEA model was constructed and main effect analysis was performed on the major shape variables affecting each objective function. Then, the optimal shape that minimizes the objective function was derived through the response surface analysis method.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.05a
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• pp.349-354
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• 2005

Recently, there are many equipment of electricity, electronics, and communication which need to grounding in the building. When the electric current flows into a certain grounding system in the same building, the potential rise of other grounding system is possible to be affected by its potential rise. This potential interference was affected by the surface potential, it is deeply related whit the electrode shape. In this paper, basic formula is deduced on the basis of both electrodes surface potential of grounding electrode in a source of the potential interference and groundidng electrode which receive the potential interference. Therefore the degree of potential interference as multiple groundidng electrode can be verified the simulated results by means of the simple model in advance. This is for investigating the grounding resistance of grounding electrodes, the experiment was performed with model-scale of the grounding system and the scaled model grounding system was to this experiment using a water tank of a stainless steel-hemisphere shape. since mesh electrodes have been widely in the general building, we're tried to analyze that this water tank model and it's simulation as well.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.2
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• pp.51-57
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• 2010

The shape of the register mark for the image processing becomes very important, because the printing quality is determined by the error correction between the register marks for the image processing. In this paper, printing marks are developed using the image process for the gravure printing method which is commonly being used in roll to roll, high resolution printing. The marks which can be cited to the flexible display print are developed The developed register marks which satisfies 10[${\mu}m$] error tolerance are tested under 70[mpm] printing conditions and confirmed through the experiments.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.1
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• pp.19-27
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• 2007

In this paper, we develope and implement a TFT-LCD cell defects detection algorithm using morphology. To detect the bright line or dark line defects and the bright pixel or dark pixel defects of the TFT-LCD cells, we determine the shape of the morphology operators considering the shape characteristics of the TFT-LCD sub pixels. Using dilation, erosion, and the subtraction operators, we extract gray level defects information. Then, we apply the optimal threshold method which shows the best results in terms of several criteria. Finally, we determine the defects using labelling method. From various experiments using TFT-LCD panels, the proposed algorithm shows superior results.

• International Journal of Highway Engineering
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• v.2 no.4 s.6
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• pp.123-131
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• 2000

The compaction equipment and the Marshall stability head are the two important testing equipment for the Marshall test. The compaction equipment is closely related to the air void, VMA and compactability of the mixtures, and the stability head is related to the Marshall stability and the flow, therefore the size and the shape of the equipment is essential for finding the accurate optimum asphalt content for the asphalt mix design. However, the size and the shape of the equipment currently used and the condition of the installation of compaction pedestal in this country are different from each agency and manufacturer. The national inspection of the Marshall equipment is necessary because the difference can affect the test results and also the performance of the asphalt pavement.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.11
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• pp.26-32
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• 2011

In this study, a standard illuminant A type LED that has similar emission spectrum as the standard illuminant A was developed using LED chip(emission peak: 405[nm]) and four types of phosphors(blue, green orangered and red). Using the design of experiment for spectrum control, the trend of the change of spectrum shape influenced by the change of interaction among phosphors and their density could be examined. Computer simulation through the optimization of the design of experiment revealed that, among four phosphors, the most influential one on the shape of the spectrum was green phosphor. Using the obtained optimal combination ratio of the four phosphors, an alternative LED illuminant to the actual standard illuminant A was developed and the spectrums of these two were confirmed identical. Using this standard illuminant A type LED, a portable transmittance meter with the range of measurement error of ${\pm}1.0$[%] was developed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.1
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• pp.3-11
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• 1998

The influence due to particle contaminated on spacer surface is remarkable in the decreasing of dielectric strength in SF6 GIS. In relation with this problem, We studied, AC flash-over voltage characteristics and breakdown mechanism are investigated under metallic and insulating particle initiated condition in SF6 gas by varying the particle position, particle shape with a plane-plane electrode. The main results are as follows $\circled1$ Influence of the flash-over voltage decrease for particle position is lowest in mid gap and is highest in separated small gap on electrode. $\circled2$ The metallic particle shape which results in the more reduced flash-over voltage, the FOV saturation moved in to the region of low pressure. $\circled3$Insulating particle less than 0.6[mm] are not almost influenced by the flash-over Voltage.oltage.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.2
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• pp.82-88
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• 2010

The purpose of this research is a seismic capacity evaluation and strengthening of existing railway station buildings, which were constructed before the seismic design code activated. The seismic capacity of 2nd story RC station building is evaluated by using nonlinear time-history analysis. Analysis results are checked by story drift ratio and story shear, which are described in design code. As a result, the story shears are exceeding the base shear of the design code, the appropriate seismic strengthening methods are needed. To improve the seismic capacity, metallic dampers are used. Evaluation parameters are metallic damper shape and damper installation methods. Dampers are installed in four places in X and Y directions of station buildings. By reviewing of time-history analysis results, the metallic damper, which is installed inverted K-brace type, shows a better seismic performance than other damper shape and installation methods.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.391-398
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• 2008

LES analysis was conducted with in-house CFD code to investigate the turbulence evolution and interaction due to turbulence ring and splash plate in the gas generator. Though chemical reaction was not accounted for, the results can be useful in determining the turbulence characteristics generated by ring and plate. The calculation results show that the installation of turbulence ring can introduce additional turbulences and improve turbulent mixing in the downstream flow. However, the addition of splash plate in the downstream of TR brings totally different shape of perturbation energy and enstrophy distribution for turbulent mixing. This enhancement can be done by the formation of the intensively strong vorticity production and mixing behind the plate. Pressure drop was found to be a reasonable level of about 1% or less of initial pressure in all calculation cases. Also, calculation results revealed that the variation of TR shape and intrusion length did not change the characteristics of turbulent mixing in the chamber. Even though the effect of installation location of splash plate on the turbulent mixing is not investigated yet, calculation results conclude the addition of splash plate leads to the increase in turbulent mixing with an acceptable pressure drop.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.3
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• pp.123-130
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• 2010

The aim of this paper is a seismic performance evaluation of metallic damper devices which are efficient in workability and installation process. For this V shape and S shape dampers is considered. The strut figures of dampers are V shape and S shape and, the research parameters are strut height and angle of the dampers. ABAQUS program is used for nonlinear finite element analysis. The analysis is performed with the hysteretic curve that has maximum displacement with 50mm and has increased progressive. As a results of evaluating the yield strength, maximum strength and energy dissipation capacity of each device, V and S shape have a good strength capacity and the devices with strut angle $60^{\circ}$ and strut height 140 and 200mm are evaluated stable in seismic behaviors. The response of S shape is more efficient than that of V shape. In the yield strength estimation process, proposed formula can not estimate the yield strength of V and S shape dampers. Even though, the formula can not consider the variation of strut heights and strut angles. Finally the S shape damper is recommended in seismic performance than V shape damper.