• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.5
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• pp.419-425
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• 2007

A rapid one-shot alignment method of the Strapdown INS (SDINS) for a vertical launch is proposed. The proposed alignment is performed using the accelerometer output of the Slave INS and the attitude of the Master INS. To improve the accuracy and the speed of the alignment, the equivalent linear transformation and the pre-filtering method are developed. Experiment results show that the proposed method is effective in improving the accuracy and the speed of the alignment.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.330-333
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• 2005

We investigated the liquid crystal (LC) alignment phenomena using a-C:H and a-C:F:H thin films. Homogeneous alignment is obtained using ion beam treated hydrogenated amorphous carbon (a-C:H) thin films. Homeotropic alignment is obtained using F treated a-C:H thin films, namely, fluorinated amorphous carbon (a-C:F:H) thin films. We investigated the relationship between the surface properties of amorphous carbon based alignment layer and LC alignment phenomena.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.1
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• pp.74-79
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• 2011

Alignment systems with multi-axis motions are applied to determine vertical arrangement of multilayer assembly such as LCD, PDP, and MLCC. This study reports the development of XY${\theta}$ alignment stage which is designed as thin-type structure and parallel actuations. The thin-type parallel XY${\theta}$ alignment stage is maintained below $1{\mu}m$ in repeatability error. The squareness and straightness also allow precise motion for the alignment by the developed stage. The measured error is ${\pm}6.25{\mu}m$ in the alignment experiment by the vision system on the parallel XY${\theta}$ alignment stage.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.4
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• pp.708-715
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• 2010

In Strapdown Inertial Navigation System, alignment accuracy is the most important factor to determine the performance of navigation. However by an existing self-alignment method, it takes a long time to acquire the alignment accuracy that we want. So, to attain the desired alignment accuracy in as little as $\bigcirc$ minutes, we have developed the precise multi-position alignment method. In this paper, it is proposed a inertial measurement matching transfer alignment method among alignment methods to minimize the alignment error in a short time. It is based on a mixed velocity-DCM matching method be suitable to the operating environment of vertical launching system. The compensation methods to reduce misalign error, especially azimuth angle error incurred by measurement time-delay error and body flexure error are analyzed and evaluated with simulation. This simulation results are finally confirmed by experimentations using FMS(Flight Motion Simulator) in Lab and the integration test to follow the fire control mission.

• Transactions on Electrical and Electronic Materials
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• v.1 no.3
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• pp.10-13
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• 2000

In this study the new photo-alignment material copoly(PM4Ch-ChMa)(copoly (poly (4-methancryloyloxy)chalcone-cholesteryl methacry late)) was synthesized, Also, the liquid crystal (LC) aligning capabilities and the electro-optical(EO) characteristics for the photo-aligned vertical-aligned(VA)-LC display(LCD) were studied. The monodomain alignment of the NLC for the photo-aligned VA-LCD by linearly polarized UB exposure on the Photo-dimerized copoly(PM4Ch-ChMA) surface was observed,. Excellent Voltage-transmittance characteristics for the VA-LCD photo-aligned by polarized UV exposure on the copoly (PM4Ch-ChMA) surfaces for 1 min was achieved. The response time of the VA-LCD photo-aligned by polarized UV exposure on the copoly (PM4Ch-ChMA) surfaces for 1 min was 39.3 ms, We suggest that the photo-dimerized chacone group increased with increasing UV exposure time, which then contributes to a low response time of the photo-aligned VA-LCD on the copoly (PM4Ch-ChMA) surfaces.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.818-821
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• 2006

We demonstrate the vertical alignment of liquid crystal on $a-SiO_x$ film surface using the ion beam exposure. Liquid crystal can be aligned vertically by the rotational oblique evaporation of $a-SiO_x$ film. However, the electro-optic switching behavior of liquid crystal along random directions results in disclination lines. We found that we can achieve highly uniform alignment of liquid crystal without disclination lines by using the ion beam exposure. We found from XRD and XPS data that the vertical alignment can be achieved when x approaches 1.5 at the $a-SiO_x$ film surface. We have shown that the pretilt angle can be controlled by changing ion beam parameters, such as the ion beam energy, the angle of incidence, and the exposure time. We found that whether liquid crystals can be aligned vertically or homogeneously on $a-SiO_x$ film can be predicted simply by measuring the change in optical transmittance by deposition of $a-SiO_x$ thin film layers. We also have shown that a liquid crystal cell aligned vertically by the ion beam exposure exhibits the voltage-transmittance curve similar to that of a rubbed polyimide cell.

• Proceedings of the KOR-KST Conference
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• 1997.12a
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• pp.33-69
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• 1997

This study was conducted to develop a methodology to predict utility pole accident rates and to evaluate cost-effectiveness for safety improvement for utility pole accidents. The utility pole accident rate prediction model was based on the encroachment rate approach introduced in the Transportation Research Board Special Report 214. The utility pole accident rate on a section of highway depends on the roadside encroachment rate and the lateral extent of encroachment. The encroachment rate is influenced by the horizontal and vertical alignment of the highway as well as traffic volume and mean speed. The lateral extent of encroachment is affected by the horizontal and vertical alignment, the mean speed and the roadside slope. An analytical method to generate the probability distribution function for the lateral extent of encroachment was developed for six kinds of encroachment types by the horizontal alignment and encroachment direction. The encroachment rate was calibrated with the information on highway and roadside conditions and the utility pole accident records collected on the sections of 55mph speed limit of the State Trunk Highway 12 in Wisconsin. The encroachment rate on a tangent segment was calibrated as a function of traffic volume with the actual average utility pole accident rates by traffic volume strategies. The adjustment factors for horizontal and vertical alignment were then derived by comparing the actual average utility pole accident rates to the estimations from the model calibrated for tangent and level sections. A computerized benefit-cost analysis procedure was then developed as a means of evaluating alternative countermeasures. The program calculates the benefit-cost ratio and the percent of reduction of utility pole accidents resulting from the implementation of a safety improvement. This program can be used to develop safety improvement: alternatives for utility pole accidents when a predetermined performance level is specified.

• Proceedings of the KOR-KST Conference
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• 1997.12b
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• pp.35-72
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• 1997

This study was conducted to develop a methodology to predict utility pole accident rates and to evaluate cost-effectiveness for safety improvement for utility pole accidents. The utility pole accident rate prediction model was based on the encroachment rate approach introduced in the Transportation Research Board special Report 214. The utility pole accident rate on a section of highway depends on the roadside encroachment rate and the lateral extent of encroachment. The encroachment rate is influenced by the horizontal and vertical alignment of the highway as well as traffic volume and mean speed. The lateral extent of encroachment is affected by the horizontal and vertical alignment, the mean speed and the roadside slope. An analytical method to generate the probability distribution function for the lateral extent of encroachment was developed for six kinds of encroachment types by the horizontal alignment and encroachment direction. The encroachment rate was calibrated with the information on highway and roadside conditions and the utility pole accident records collected on the sections of 55mph speed limit of the State Trunk Highway 12 in Wisconsin. The encroachment rate on tangent segment was calibrated as a function of traffic volume with the actual average utility pole accident rates by traffic volume strategies. The adjustment factors for horizontal and vertical alignment were when derived by comparing the actual average utility pole accident rates to the estimations from the model calibrated for tangent and level sections. A computerized benefit-cost analysis procedure was then developed as a means of evaluating alternative countermeasures. The program calculates the benefit-cost ratio and the percent of reduction of utility pole accidents resulting from the implementation of a safety improvement. This program can be used to develop safety improvement alternatives for utility pole accidents when a predetermined performance level is specified.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.6 no.4
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• pp.71-75
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• 2007

Geometrical error of ultra-precision machining due to spherical tool alignment error is analyzed. Deviation of spherical edge, ranged several ten micrometers, generates vertical and horizontal error of tool path and affects profile accuracy of machined surface. Simulation of machined error shows effect of tool alignment error and enables to estimate alignment error. This work provides technical insights into the minimizing of geometrical error of ultra-precision machining.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2012.06a
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• pp.175-175
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• 2012

Proper shaft alignment is one of the most important actions during the design of the propulsion system. The stiffness of recently designed marine propulsion shafting has been increasing remarkably, whereas hull structures have become more likely to deform as a result of optimized design of the scantlings and the high tensile steel. Therefore, to obtain the optimum status in shafting alignment at the design stage, it is strongly recommended that the change of bearing reaction force depending on ballast/load condition, the bending moment force occurred by propeller thrust, elastic deformation of bearing occurred by vertical load of shaft mass and etc., should be considered. This paper dealing with introduction of shaft alignment concerning long shaft for high speed vessel and review its reliability evaluation theoretically.