• Bulletin of the Korean Space Science Society
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• 2011.04a
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• pp.31.1-31.1
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• 2011

In this study, we investigated alignment state estimation performances of the three methods i.e. merit function regression (MFR), differential wavefront sampling (DWS) and Multiple Design Configuration Optimization (MDCO). The three target optical systems are 1) a two-mirror Cassegrain system for deep space Earth observation, 2) intermediate size three-mirror anastigmat for Earth ocean monitoring, and 3) extremely large segmented optical system for astronomical observation. We ran alignment state estimation simulation for several alignment perturbation cases including 1mm to 10mm in decenter and from 0.1 to 1 degree in tilt perturbation error for the two-mirror Cassegrain system. In general, we note that MDCO shows more competitive estimation performance than MFR and DWS. The computational concept, case definition and the simulation results are discussed with implications to future works.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.2
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• pp.118-126
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• 2014

In this paper, a new method is proposed for the five-degree-of-freedom precision alignment and stitching of three-dimensional surface-profile data sets. The control parameters for correcting thealignment error are calculated from the surface profile data for overlapped areas among the adjacent measuring areas by using the "least squares method" and "maximum lag position of cross correlation function." To ensure the alignment and stitching reliability, the relationships betweenthe alignment uncertainty, overlapped area, and signal-to-noise level of the measured profile data are investigated. Based on the results of this uncertainty analysis, an appropriate size is proposed for the overlapped area according to the specimen's surface texture and noise level.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.564-566
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• 1992

It is tragic that the Korean Airline Boing 747, KE007, wandered hundreds of miles off course into Soviet airspace and was shot down on September 1, 1983. The exact cuases are not known yet. Thus, speculation centers on human error or faulty procedure of three Litton LTN-72R inertial navigation systems(INS) with which the KAL KE007 was equipped. The inertial platform must be aligned before the INS can be used as a precision inertial navigation system. This analysis checks a possibility that the navigation errors are caused by a wrong INS alignment procedure assuming it is done at Anchorage. Possible causes for the navigational position error, such as alignment errors and gyro drift errors, are analyzed through inertial navigation system error prapagation simulations. A set of misalignment angle is estimated to determine what degree of alignment errors are required to cause the navigation error assuming that the accident is caused by the INS misalignment.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.6
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• pp.27-38
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• 2012

In this paper, we introduce CoMP in 3GPP LTE-Advanced Release 11 to take care of shadowing effects appearing in cell-edge areas to meet rapidly increasing demand for high speed transmission and multi-media data. In order to mitigate interference, orthogonalizing is ideal but it is slightly difficult to be applied to real systems. Therefore, interference alignment and avoidance are used in practical applications. Interference alignment is a scheme enabling us to consider interference our friend not enemy. We show lattice codes in Gaussian channel achieve Shannon capacity where strong interference exists. In addition, we show the relationship between channel parameter a and DoF(Degree of Freedom) applying lattice codes to interference alignment for interference channel with three users.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.6
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• pp.499-504
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• 2001

We evaluated the degree of texture through depth of the superconductor core of Bi-Sr-Ca-Cu-O(BSCCO) superconductor tape. The degree of texture was characterized by pole figure analysis indicating that the degree of texture varied significantly with depth of the superconductor core. It was observed that the degree of texture was higher near the interface than inside the superconductor core. Specifically, as getting near to the center from the sheath/core interface, the orientation of BSCCO became dispersed from normal direction(ND) which, in turn, resulted in the degradation of <001>-fiber texture. In addition, the <001> texture was non-uniform an, better texture was developed along rolling direction(RD), compared to transverse direction(TD). Microstructural investigation showed that grain alignment was locally degraded by the existence of second phases. I was observed that larger grain size and better texturing were developed near the relatively straight interface compared to those inside the superconducting core. Based on our study, the region near the interface is thought to carry significant current compared to that inside the core.

• Composites Research
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• v.31 no.4
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• pp.171-176
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• 2018

We proposed new and easy fabrication method of micro-nano hierarchical structures for synthetic dry adhesives and conducted feasibility tests of alignment characteristics of nano-materials in the microstructures by capillary effect. Candidates of fabrication conditions were selected based on the degree of cure and viscosity of mixtures of multiwall carbon nanotubes (MWCNTs) and polydimethylsiloxane (PDMS), which were measured with respect to the fabrication conditions. Scanning electron microscopy images of cross sections of MWCNT-PDMS microstructures were analyzed. MWCNT alignment in microstructures was better when fabrication temperature and degree of cure at fabricating start were lower, but areal density of MWCNTs was little affected by fabrication conditions.

• Physical Therapy Rehabilitation Science
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• v.5 no.2
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• pp.84-88
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• 2016

Objective: Generally, it is known that there is a correlation between excessive calcaneus eversion and a patient with low back pain and it also affects pelvic alignment. However, there are not enough studies that show calcaneal eversion having an effect on the alignment of the trunk. Design: Cross-sectional study. Methods: A 3-dimensional motion analysis system was used to assess the lower limbs, pelvic alignment, and trunk alignment with increased unilateral and bilateral calcaneal eversion in twenty-one subjects. All subjects were asked to maintain a static posture for seven seconds on a wedge three times per posture for measurement and analysis purposes. The wedge used in the process was a lateral wedge with a 10-degree tilt to the lateral direction. To unify all of the subjects' foot position, the front and inner side of the wedge were marked. The height of the tilted wedge's inner side and flat wedge were balanced equally in order to be able to maintain the lateral part of the foot to the same height when producing an increased calcaneal eversion. Results: Comparing the changes in trunk and pelvic alignment in accordance to calcaneal eversion for each posture, there was a significant different in the X and Y-axis for each posture, but not in the Z-axis (p<0.05). Thus, it can be confirmed that calcaneal eversion in the sagittal plane and frontal plane may have and effect on the pelvis and the trunk. Conclusions: Postures with increased bilateral and unilateral calcaneal eversion has an effect on pelvic alignment, but does not cause any changes in trunk alignment.

• Journal of the Korean Operations Research and Management Science Society
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• v.36 no.2
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• pp.67-88
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• 2011

This study empirically investigated the effects of knowledge management(KM) strategic alignment on the KM activities as well as the product and process innovation of manufacturing firms. Based on the framework, which employs the usage levels of target costing systems(TCS) and information technology(IT) infrastructure, four types of KM strategies were identified and proposed：mixed, explorative, exploitative and negative strategies. In this research, these four types of KM strategies were empirically validated. According to the results of this study, it was found that when a explorative KM strategy is aligned with a low-cost strategy, KM activities are activated and the degree of a process innovation is increased. It was observed that in the case of the alignment between a differentiation strategy and a exploitative KM strategy, both KM activities and the level of a product innovation are enhanced. The results also demonstrated that for the enhancement of both a process and a product innovation through the activation of KM activities, a mixed KM strategy must be aligned with a composite business strategy, which focuses on a low-cost as well as a differentiation strategies. Accordingly, it is concluded that the KM activities and the levels of the product and process innovation can be activated or improved with the alignment of the KM strategies and business strategies.

• Transactions on Electrical and Electronic Materials
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• v.9 no.3
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• pp.120-122
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• 2008

We have studied the tilt angle generation on the homeotropic polyimide (PI) surface using a low intensity ion beam source as a function of incident angle. An excellent LC alignment of nematic liquid crystal (NLC) on the PI surface with ion beam exposure for all incident angles was observed. The tilt angle of NLC on the homeotropic PI surface for all incident angles was from 90 to 88 degree was observed. Also the tilt angle of NLC on the homeotropic PI surface with ion beam exposure of 400 eV had a tendency to increase as ion beam energy incident angle become more instance from 45 degree. Finally, a good LC alignment thermal stability on the homeotropic PI surface with ion beam exposure can be achieved.

• Journal of Information Display
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• v.5 no.2
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• pp.39-42
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• 2004

A novel fast-switching LCD with dual-domain bend (DDB) mode is described. DDB alignment is achieved using antiparallel-rubbed cell filled with chiral-doped LC. Initial alignment is mono-domain 180-degree twist. Tilt direction is controlled by oblique electric field to be counter direction in each domain. Twist-to-DDB deformation occurs continuously so that DDB mode does not require high-voltage initialization which is inevitable in Optically Compen sated Bend (OCB) mode. DDB gives wide and symmetric viewing angle in contrast to mono-domain bend formed from 180-degree twist showing strong asymmetry.