• The Korean Journal of Ceramics
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• v.3 no.3
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• pp.191-194
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• 1997

Epitaxial Pb(Zr, Ti)O3(PZT) thin films were prepared on MgO(100) substrates by dipping-pyrolysis (DP) process using metal naphthenates as starting materials, and effects of pyrolysis and final heat-treatment conditions on the film's orientation were investigated. Solid-state epitaxial growth of PZT proceeds at lower temperature around 650℃ from the precursor pyrolyzed at 350 and 500℃. The in-plane alignment of the PZT films depends not only on the final heat-treatment temperature but on the pyrolysis conditions; the films, pyrolyzed at a higher temperature for a short time, i.e., at 500℃ for 10 min, exhibited stronger orientation after the same final heat treatment at 650°∼750℃. The PZT films with the strongest orientation were prepared by pyrolysis under the above conditions followed by final heat treatment at 750℃.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.4
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• pp.306-313
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• 1998

To elucidate the liquid crystal(LC) molecules alignment mechanism, it is important to determine the molecular orientation of the rubbed polymer surface molecules that directly contact with LC molecules. In this work, the molecular orientation on a rubbed surface of polyimide (SE-3310, Nissan) film has been studied by polarized FTIR absorption spectroscopy. It has been found that molecular chain on the rubbed surface of polymide film are oriented along the rubbing direction and are tilted up on an average by 5.0$^{\circ}$. In the SHG(Second Harmonic Generation) measurement, the pretilt angle of molecular chain on the poylmide fim was 4.6$^{\circ}$ fro, the surface plane. And the pedit angle of liquid crystal (ZLI-2293, Merck) molecules measured by crystal rotation method was 5.4$^{\circ}$in the same rubbing condition.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.11
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• pp.821-825
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• 2013

Effect of multi-stacked layer (MSL), 0.1 mol (M) and 0.3 mol (M) hafnium oxide ($HfO_2$) alignment layers were fabricated via a solution-process for LCs orientation. The solutions were spin-coated and annealed in a furnace. MSL consists of three sub-layers using 0.1 M solution, mono-layer (ML) is composed of 0.3 M $HfO_2$ solution. Then ion-beam irradiation was treated with 1.8 keV for 2 min. $HfO_2$-based LC cells were investigated through photographs, pre-tilt angle using crystal rotation method, X-ray photoelectron spectroscopy (XPS) measurement, and surface roughness using atomic force microscopy(AFM) for their characteristic research. Good LC orientation characteristics were observed on MSL $HfO_2$ surface. The LC alignment mechanism on MSL $HfO_2$ and ML $HfO_2$ surfaces was attributed to van der Waals (VDW) interaction between the LC molecular and substrate surface.

• International Area Studies Review
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• v.13 no.3
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• pp.481-500
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• 2009

This paper investigates the Moderating effect of entrepreneurship on the relationship between market orientation and international performance in Korean Ventures. Literature revealed that an appropriate alignment between firm strategic orientation and market positioning is critical because of its impact on firm performance. The alignment is especially crucial for SMEs as a result of their limited resource base. However, studies have not adequately accounted for the joint effect of entrepreneurship and market orientation on firm performance in different environments as foreign markets. Drawing upon a sample of 217 internationalized Korean Venture Business, it presents evidence related to mainly moderating effects of entrepreneurship on market orientation-international performance. The Key conclusion from the evidence is that market orientation, alone and in conjunction with certain entrepreneurship dimensions, is positively related to firm international performance. More specifically innovativeness and proactiveness have positively moderated the relationship between market orientation and international performance in Korean Ventures.

• Fibers and Polymers
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• v.6 no.3
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• pp.186-199
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• 2005

A selection of commercially available poly(ethy1ene terephtha1ate) fibers with different degrees of molecular alignment and crystallinity have been investigated utilizing a wide range of techniques including optical microscopy, infrared spectroscopy together with thermal and wide-angle X-ray diffraction techniques. Annealing experiments showed increased molecular alignment and crystallinity as shown by the increased values of birefringence and melting enthalpies. Crystallinity values determined from thermal analysis, density, unpolarized infrared spectroscopy and X-ray diffraction are compared and discussed in terms of the inherent capabilities and limitations of each measurement technique. The birefringence and refractive index values obtained from optical microscopy are found to decrease with increasing wavelength of light used in the experiments. The wide-angle X-ray diffraction analysis shows that the samples with relatively low orientation possess oriented non-crystalline array of chains whereas those with high molecular orientation possess well defined and oriented crystalline array of chains along the fiber axis direction. X-ray analysis showed increasing crystallite size trend with increasing molecular orientation. SEM images showed micro-cracks on low oriented fiber surfaces becoming smooth on highly oriented fiber surfaces. Excellent bending characteristics were observed with knotted fibers implying relatively easy fabric formation.

• Journal of Electrical Engineering and Technology
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• v.8 no.6
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• pp.1457-1461
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• 2013

The effect of liquid crystal (LC) alignment on a homeotropic polyimide (PI) surface induced by ion beam (IB) irradiation and rubbing process was studied. LC alignment was not affected by IB irradiation with an exposure time of 10 s, and an IB irradiation with an exposure time of 60 s more effectively oriented the LCs on the PI layer than the rubbing process. It was assumed that the LC alignment depended on the C-O bonds created from the C=O bonds on the PI surface broken by IB irradiation after an exposure time of 60 s, which resulted in a strong surface energy that transformed the homeotropic LC alignment to homogeneous states.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.161-161
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• 2009

Ion bombarded inorganic materials for LC alignment has been researched as it provides controllability in a nonstop process for producing high-resolution displays. Many optically transparent insulators such as $SiOx$ and a-C:H have been investigated as potential candidates for inorganic alignment materials. Even so, LC orientation on a new material with superior capacity is required to produce high-performance displays. Many inorganic materials with high permittivities can reduce the voltage losses due to the LC alignment layer that are a trade-off for its capacitance. The minimum voltage for device operation can be applied to the LC under low external voltage using these materials. This means that low power consumption for LCD applications can be achieved using a high-k alignment structure in which the LC can be driven effectively with a low threshold voltage. Among the many other potential high-k oxides, HfO2 is considered to be one of the most promising due to its remarkable properties of high dielectric constant, relatively low leakage current, large band gap (5.68 eV), and high transparency. Due to these characteristics, HfO2 can be used in LC alignment to increase the capacitance of the inorganic alignment layer for low-voltage driving of LCs.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.12
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• pp.987-995
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• 2020

Accurate alignment between high-performance payloads and attitude control sensors is essential factor to guarantee accurate attitude orientation and high pointing stability of the satellite. Space craft developers often use theodolite measurement system for satellite alignment during ground AIT(Assembly Integration and Test) phase. When measuring theodolite, errors may occur due to line of sight error, tilting axis error, vertical index error, and vertical axis error. In addition, errors that can occur during alignment measurements with multiple theodolites are analyzed through the alignment cube measurements test. Based on the alignment cube measurements test, a technical method that can improve the alignment measurement accuracy was suggested and it's measurements results satisfied the satellite design requirements.

• Journal of the Korean Wood Science and Technology
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• v.36 no.2
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• pp.56-62
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• 2008

The surface and edge structure of OSB is defined by surface strand orientation and strand mat thickness variation parallel to the length of the panel using video-microscope. The bending strength of OSB was correlated with surface strand orientation and decreased with increasing the orientation angle in the direction parallel to length of the panel. Average strand mat thickness variation parallel to the length of the panel did not influence the bending strength, but the bonding characteristics among the outermost strands affects the bending strength of OSB. Hankinson formula can be used to predicts the MOE according to strand orientation in the surface of OSB, and more precise strand alignment and reducing thickness variation should be important in the structural performance of OSB panels.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.301-301
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• 2008

Ion beam (IB)-induced alignment of inorganic materials has been investigated intensively as it provides controllability in a nonstop process for producing high-resolution displays[1][2]. LC orientation via ion-beam (IB) irradiation on the nitrogen doped diamond like carbon (NDLC) thin film deposited by physical deposition method-sputtering was embodied. The NDLC thin film that was deposited by sputter showed uniform LC alignment at the 1200eV of the ion beam intensity. The pretilt angle of LC on NDLC thin films was measured with various IB exposure time and angle. The maximum pretilt angle were showed with IB irradiation angle of $45^{\circ}$ and exposure time of 62.5 sec, respectively. To show NDLC thin film stability in high temperature, thermal stability test was proceeded. The uppermost of the thermal stability of NDLC thin film was $200^{\circ}C$. In this investigation, the electro-optical (EO) characteristics of LC on NDLC thin film were measured.