• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.208-208
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• 2009

We used Brewster's Law to examine the mechanism of liquid crystal (LC) alignment on an organic insulation layer when subjected to ion-beam irradiation. Brewster's Law implies that the maximum rate polarized ray on a slanted insulation layers on the substrate and it illustrates the dependence of polarization and themechanical structure on the ion beam irradiation process. The pretilt angle of nematic LCs on the organic insulation surface was about $1.13^{\circ}$ for an ion beam exposure of $45^{\circ}$ for 1 minute at 1800eV. This shows the dependence of LC alignment on the polarization ratio in a slanted organic insulation layer.

• Transactions on Electrical and Electronic Materials
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• 제17권6호
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• pp.355-358
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• 2016

We present the alignment characteristics of LC (liquid crystal) molecules on solution-derived HLO (hafnium lanthanum oxide) films fabricated using IB (ion-beam) irradiation. We then demonstrated that LC molecules can be homogeneously and uniformly aligned on the HLO film irradiated at an IB incident energy of 1.2 keV. Physicochemical analysis methods such as atomic force microscopy and X-ray photoelectron spectroscopy were used to verify the LC alignment mechanism on the IB-irradiated HLO film. In addition, the electro-optical performance of a TN (twisted-nematic) cell fabricated using the IB-irradiated HLO film exhibited characteristics superior to those of the conventional TN cell fabricated using a rubbed polyimide layer.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.483-486
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• 2002

Toggle bolt is mechanical device constructed with toggle spring wing toggle and machine screw, and defined as an expansive bolt consisting of a nut with flanged wings which are pressed to the bolt and, after insertion in a thin or hollow wall, spread open through spring pressure, thus anchoring it to the wall. And spring wing toggle is aligned with two wings, spring and nut manually in domestic manufacturing line. Then it is regarded as major problem for exports increasement to make cost down in the view of total manufacturing process. Accordingly in this study, high speed type automatic alignment mechanism is guided for spring wing bolt, and exclusive alignment dies and some special additional units are designed and manufactured.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.429-429
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• 2000

Micro positioning mechanism is the key technology in many fields, such as scanning electron microscopy (SEM), x-ray lithography, mask alignment and micro-machining. In the paper, a 3DOF parallel-type micro-positioning mechanism is proposed. This mechanism uses piezo-actuators and Flexure hinge to control x, y and $\theta$ motion. It is shown both analytically and numerically that 2 DOF flexure hinge model was better precision than 1 DOF flexure hinge design.

• 한국공작기계학회논문집
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• 제15권1호
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• pp.8-16
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• 2006

The communication through optical fiber is taking an important role of the expansion of communication network with excellent transmitting rate and quality. As the optical communication is introduced to the backbone network at first and becomes a general communication method of network, the demand of kernel parts of optical communication such as PLC(Planar Light Circuit), Coupler, and WDM(Wavelength Division Multiplexing) element increases. The alignment and the attachment technology are very important in the fabrication of optical elements. In this paper, the driving mechanism of ultra precision stage is studied with the aim of optimal design of stage. The travel and the resolution of stage are investigated. The hysteresis of the stage is generated because of PZT actuator. The hysteresis and the inverse hysteresis are modeled in X, Y, and Z-axis motion. The input data of desired displacement of the stage according to input voltage is obtained from the inverse hysteresis equation. In the result of experiments with the input data, the errors due to hysteresis are well compensated.

• Genomics & Informatics
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• 제6권1호
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• pp.44-49
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• 2008

Protein kinase C (PKC) is a family of kinases involved in the transduction of cellular signals that promote lipid hydrolysis. PKC plays a pivotal role in mediating cellular responses to extracellular stimuli involved in proliferation, differentiation and apoptosis. Comparative analysis of the PKC-${\alpha},{\beta},{\varepsilon}$ isozymes of 200 recently sequenced microbial genomes was carried out using variety of bioinformatics tools. Diversity and evolution of PKC was determined by sequence alignment. The ser/thr protein kinases of Streptomyces coelicolor A3 (2), is the only bacteria to show sequence alignment score greater than 30% with all the three PKC isotypes in the sequence alignment. S.coelicolor is the subject of our interest because it is notable for the production of pharmaceutically useful compounds including anti-tumor agents, immunosupressants and over two-thirds of all natural antibiotics currently available. The comparative analysis of three human isotypes of PKC and Serine/threonine protein kinase of S.coelicolor was carried out and possible mechanism of action of PKC was derived. Our analysis indicates that Serine/ threonine protein kinase from S. coelicolor can be a good candidate for potent anti-tumor agent. The presence of three representative isotypes of the PKC super family in this organism helps us to understand the mechanism of PKC from evolutionary perspective.

• 동의생리병리학회지
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• 제22권2호
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• pp.459-463
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• 2008

Postural balance of temporomandibular joint (TMJ) reflects the neuromuscular balance. TMJ posture treatment for meridian yinyang balance has been asserted to have an impact upon cervical spine alignment with an episodic good clinical result for refractory torticollis cases. A retrospective study with one-group pretest-posttest design was conducted to review cervical spine imaging data and clinical symptom changes in cervical dystonia cases to explore the effect of TMJ balance treatment. Review of clinical symptoms and cervical spine imaging data including computed tomography and simple x-ray of 9 cervical dystonia cases revealed significant improvement of cervical spine alignment and clinical symptoms. Improvement of cervical spine alignment may be an underlying mechanism of TMJ balance treatment, as a way of balancing the whole-body meridian system.

• 한국전기전자재료학회논문지
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• 제13권2호
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• pp.151-156
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• 2000

Effects of alignment layers on pretilt nagle generation and electrical characteristics in nematic liquid crystal(NLC) by using photo-alignment techniques on polyimide PI) surface with side chain were studied. The generated pretilt angle of the NLC on rubbed PI surface with 1-layer is almost the same as that with the 2-layers. However, the generated pretilt angle of the NLC on photo-induced PI surface with 2-layers is larger than that with the 1-layer. The different mechanism of pretilt generation in NLC was observed on the rubbing and photo-alignment method. Therefore, the pretilt angle of the NLC on photo-induced PI surface is attributed to surface roughness due to photo-dissociation on the polymer with UV light irradiation on PI surface. We observed the same characteristics of voltage-transmittance (V-T) and response time for 1- and 2-layers on PI surface. Consequently, we sugest that the VHR of photo-aligned TN-LCD is higher than that of the rubbing-aligned TN-LCD.

• 한국자기학회지
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• 제5권5호
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• pp.416-420
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• 1995

An attempt has been made to investigate the mechanism of magnetic alignment in the magnets produced by upset forging the $Pr_{20}Fe_{74}B_{4}Cu_{2}$ cast bulk alloy. Upset forging of the cast alloy was carried out for 20 sec to an 80 % thickness reduction (strain rate : $4{$\times}10^{-2}s^{-1}$) in an open die configuration at varying temperatures in the range $600^{\circ}-900^{\circ}C$. It has been found that the upset forging process at temperatures above $800^{\circ}C$ can achieve a magnetic alignment to a great extent from copper-containing Pr-Fe- B-type cast ingot. The growth manner of the ferromagnetic $Pr_{2}Fe_{14}B$ matrix grain in Pr-Fe-B-type alloys was studied by examining the morphology change of the matrix grain in sintered body, and it was found that the matrix grains grew in anisotropic manner such that the grain grew more rapidly along the a- or b-axis than along the c-axis. This anisotropic grain growth led to the plate-like shape of the matrix grain. The magnetic alignment during the upset forging was attributed to grain boundary gliding of the plate-like grains, and the geometry of the grains in the cast ingot and the presence of a large amount of the praseodymium-rich grain boundary phase were thought to play a key role in the achievement of magnetic alignment.

• 한국생산제조학회지
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• 제21권3호
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• pp.479-486
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• 2012

This paper presents a high-speed automatic micro-alignment system that is a part of an inspection machine for small-sized molded lenses of mobile phones, palm-top computers, and so on. This work was motivated by the shortcomings of existing highest-grade commercial machine. A simple tip/tilt/Z parallel mechanism is designed based on kinematic couplings, which is a 3-degree-of-freedom (3-DOF) moderate-cost alignment stage. It is used to automatically adjust the posture of each lens on the tray, which is impossible by the conventional instrument. Amplified piezoelectric actuators are used to ensure the accuracy and dynamic response. Forward kinematic analysis and simulation show that the parasitic motion is small enough compared to the actuator stroke. From the workspace analysis of the moving platform, it is clear that the output motion range satisfies the design requirements.