• Transactions on Electrical and Electronic Materials
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• v.5 no.1
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• pp.15-18
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• 2004

We studied the nematic liquid crystal (NLC) aligning capabilities using the new alignment material of a-C:H thin film by plasma enhanced chemical vapor deposition (PECVD) system for 30 sec under 30W rf power at a gas pressure of 1.4＊10$\^$-1/ torr. A high pretilt angle of about 5 by ion beam exposure on the a-C:H thin film surface was measured. A good LC alignment by the ion beam alignment method on the a-C:H thin film surface was observed at annealing temperature of 250$^{\circ}C$, and the alignment defect of NLC was observed above annealing temperature of 300$^{\circ}C$. Consequently, the high LC pretilt angle and the good thermal stability of LC alignment by the ion beam alignment method on the a-C:H thin film by PECVD method as working gas at 30W rf bias condition can be achieved.

• Journal of the Korea Institute of Military Science and Technology
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• v.6 no.1
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• pp.21-29
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• 2003

The Strap Down Inertial Measurement Unit(SDIMU) is recently used for the sensor package of the modern underwater vehicles such as torpedoes and unmanned underwater-vehicles. For using SDIMU, an initial alignment must be carried out before the fire or navigation stage. The general initial alignment methods require that a mother vehicle Is a stationary condition or the Inertial Navigation System(INS) of vehicle is received the specific of data navigation from the mother vehicle. But an underwater vehicle dropped from aircraft is hard to satisfy above both necessary conditions of the general initial alignment. So, we suggest a new strap down initial alignment method of an underwater vehicle dropped from aircraft without using any aided sensors. The highlight point of this method is that a period of initial alignment is not before the fire but during running stage to fix alignment error. And we verify it by analyzing various data of S/W simulations, Hardware In the Loop Simulation(HILS) tests and sea trials.

• Korean Journal of Applied Biomechanics
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• v.28 no.2
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• pp.119-125
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• 2018

Objective: The purpose of this study was to compare the effect of different 12-week exercise programs for posture correction on postural alignment in elderly women. Method: The study included 36 elderly women who were randomly divided into 3 groups: Group A (core exercise, n=12), Group B (combined exercise, n=12), and Group C (Pilates exercise, n=12). Postural alignment was measured using 6 variables in frontal and sagittal planes. Two-way mixed analysis of variance was used to compare the effect of exercise program types on postural alignment and a paired t-test was used to compare differences in postural alignment after exercise. Results: The core exercise group showed statistically significant improvement (p<.05) in multiple upper and lower body postural alignment measurements. The combined exercise and Pilates exercise groups showed statistically significant improvement (p<.05) in upper body measurements alone. Conclusion: Core exercise, combined exercise, and Pilates exercise improved postural alignment in elderly woman through improvement in muscle strength and ligament flexibility around the spine and pelvis.

• Journal of International Academy of Physical Therapy Research
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• v.11 no.4
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• pp.2184-2190
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• 2020

Background: Although studies have been conducted on muscle thickness and balance in trunk stabilization exercise and exercise using vibration props, studies on trunk stabilization exercise using active vibration for spinal alignment are still insufficient to draw a conclusion. Objectives: To investigate the effect of trunk stabilization exercise using active vibration on the spinal alignment in adult females. Design: A randomized controlled trial. Methods: Twenty-six adult females were randomly assigned to the experimental group (active vibration) and 13 control groups (active non-vibrating) and exercised three times a week for 8 weeks. Each group was measured for spinal alignment before exercise and 8 weeks after exercise. Spinal alignment, trunk imbalance, pelvic tilt, and pelvic torsion were measured using a spinal alignment analyzer. Results: Trunk imbalance was a significantly different depending on the time in the experimental group and the control group (P<.05). Pelvic tilt was a significant difference between the groups (P<.05). Also, pelvic tilt was a significantly different depending on the time in the experimental group (P<.05), but the control group showed no significant difference (P>.05). Pelvic torsion was no significant difference in both groups (P>.05). Conclusion: This study demonstrates that trunk stabilization exercise using active vibration has a positive effect on the alignment of the spine.

• 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.

• Nuclear Engineering and Technology
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• v.54 no.10
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• pp.3703-3716
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• 2022

Target alignment technology is one of the most critical technologies in laser fusion experiments and is an important technology related to the success of laser fusion experiments. In this study, by combining the open-loop and closed-loop errors of the target alignment, the Kalman state observer is used to estimate the position of the target, which improves the observation precision of the target alignment. Then the optimized result is used to guide the alignment of the target. This method can greatly optimize the target alignment error and reduce uncertainty. With the improvement of the target alignment precision, it will greatly improve the reliability and repeatability of the experiments' results, thereby improving the success rate of the experiments.

• Journal of Advanced Navigation Technology
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• v.26 no.4
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• pp.195-204
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• 2022

In this paper, we described the rapid initial alignment techniques of projectile navigation system for use in inclined launch systems. One-shot alignment technique, one of the rapid initial alignment techniques, is possible to align a navigation system within seconds because it uses external information from an launcher navigation system. However, since it has only been used in vertical launch systems, its performance in inclined launch systems has not been verified. Therefore, this paper analyzed the error elements that occur when the one-shot alignment technique is applied to the inclined launch system, and introduced a method to improve the alignment performance by minimizing those errors. Additionally, By simulating and testing the performance of the proposed alignment technique, it was verified that it is effective even in an environment where a real navigation system is used.

• Polymer(Korea)
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• v.27 no.5
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• pp.484-492
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• 2003

How the characteristics and stability of the rubbing-induced alignment of nematic liquid crystals (LCs) relate to the interfacial characteristics of LC-polyimide has been studied. The characteristics of the LC alignment (such as the LC texture, the pretilt angle, and the anchoring energy) and their thermal stability have been investigated for 5 polyimides synthesized for this work. The work showed that the rubbed polyimide alignment layer induces the strong LC anchoring and that the characteristics and stability of LC alignment are determined by the short-ranged interactions between LC and polyimide molecules at the alignment layer surface. The increased flexibility of the polyimide accelerates thermal imidization, increases the pretilt angle, and improves the alignment stability. It also turned out that fluorination of the polyimide tends to deteriorate the alignment uniformity and stability. No distinct differences in the alignment characteristics were shown for the aromatic- and alicyclic-dianhydride polyimides.

• Journal of The Korean Society of Integrative Medicine
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• v.6 no.2
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• pp.99-106
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• 2018

Purpose : Various studies effects of mental practice. However, there is a lack of research on the effects of practice on postural alignment. Therefore this study to the effect of ankle exercise combined with mental practice on postural alignment of legs. Method : Subjects were randomly assigned to mental practice group (experimental group n=15) and general exercise group (control group n=15). Postural alignment was the hip, knee, and ankle joints. When viewed from the side, an arbitrary point in front of the malleolus makes a straight line with the plumb line. Exercise was performed a week for weeks. Exercise programs included muscle strengthening, relaxation, and proprioception exercise. The experimental group mental practice. Result : Both groups showed significant differences in postural alignment ankle joint, knee joint, and hip joint. In particular, the experimental group showed a larger change than the control group. However, significant difference in postural alignment change only the knee joint (p<0.05), and there was no significant difference the hip joint (experimental group=$0.77{\pm}0.81$, control group=$0.87{\pm}1.13$) and ankle joint (experimental group=$0.52{\pm}0.63$, control group=$0.48{\pm}0.41$). Conclusion : This study suggests that mental practice is effective as an exercise method postural alignment. Mental practice also expected to be musculoskeletal disorders. Therefore, additional studies should be conducted to verify the effect of mental practice on the alignment of various parts.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.5
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• pp.651-657
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• 2023

Railroad alignment improvements and operating speed increase occupy considerable portion in recent railroad market. Developing countries have limitations to construction of new high speed railroads due to the burden of budgets and the lack of demands, and the projects of operating speed increase arepracticallyrecommended. Thisstudy developed the methodologyto provide the railroad alignment design alternatives and the costs by upgrading the "Intelligent Railroad Alignment Design Program (ei-Rail)" which has been used to obtain the alignment plans and construction costs for railroad construction projects. The program provides the cost for alignment improvement, design drafts and the effects of operating speed increase with the input of target improvement speed and the prevailing railroad alignment on the numerical map. It is then expected for the ei-Rail program to be used for the supporting tool for the railroad alignment improvement projects.