• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.182-185
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• 1998

This paper describes a field orientation control of an induction motor without any speed transducer and proposes a wide-range speed control strategy with the field orientation algorithm. The difference at impedances between the direct and quadrature axis at the injected signal is used for the sensorless field orientation control. But this algorithm has some limitations and should be supported by other method at high speed. In this paper, a sensorless speed control at an induction motor for wide speed range operation is proposed. The proposed algorithm is verified by experimental results.

• Progress in Superconductivity and Cryogenics
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• v.24 no.3
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• pp.52-56
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• 2022

Single-grain (c-normal or c-parallel) and multi-grain YBCO superconductors were prepared by a melt growth process with/without seeding. The magnetic levitation force and trapped magnetic field at liquid N₂ temperature (77 K) of the YBCO superconductors were investigated. Samples for the levitation force measurement were zero-field cooled (ZFC) to 77 K, and samples for trapped field measurement were field-cooled (FC) using Nd magnets. As for the magnetic levitation force, the c-normal, single grain sample showed the largest value, whereas the multi-grain sample showed the lowest value. The trapped magnetic field of the c-normal and c-parallel single-grain samples was 4-5 times that of the multi-grain sample. In addition, as the external magnetic field (the number of magnets) increased, the both properties increased proportionally. These results were explained in terms of the orientation dependence of the levitation forces and the magnetic field trapping capability of the YBCO superconductor.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.4
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• pp.91-99
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• 2018

Mechanical Properties of Rock Slope as a safe and effective interpretation should be thoroughly investigated. Clinometer, however, this new measurement due to the restrictions of the research for the joint orientation is needed. In this study, characteristics of the joint orientation can be used to analyze the joint orientation of developing a joint survey system that can be applied to the field. The system is developed and Analysis software to hardware. Hardware is composed to measure the joint orientation of measuring module, measuring the transfer of data transfer module. From the software is measuring module from the data to analyze the orientation of the joint development, and drone joint orientation survey system named. Can not be measured by the investigation, including regional development approach is a system that has been difficult if the Field Application of the lab test results of the joint orientation and effectively.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1098-1101
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• 1995

NbTi thin films were prepared on Si wafer and Cu substrate by rf magnetron sputtering in the range of sputtering pressure $3{\times}10^{-2}$torr to $3{\times}10^{-4}$torr at room temperature. The influence of sputtering pressure and substrate type on crystallographic orientation and morphology of NbTi thin films was investigated by using X-ray diffraction(XRD) and scanning electron microscopy(SEM), respectively. And the effect of crystallographic orientation and morphology of NbTi film on electromagnetic behaviors was estimated by measuring critical current in various applied magnetic field. The film morphology changed from porous structure consisting of tapered crystallites to densely deposited film decreasing with sputtering pressure. The change of crystallographic orientation with the sputtering pressure and rf power was calculated from the texture coefficient of(002) plane based on XRD patterns. It was found that a change of texture coefficient of(002) plane increased with decreasing sputtering pressure. From observation of critical current in various applied magnetic field, we have identified that the change of critical current abruptly decrease applying with magnetic field and NbTi film produced at high sputtering pressure does not exhibit superconductivity but at low sputtering pressure shows superconductivity.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.415-418
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• 2005

To understand effects of carbon nanotubes (CNTs) dispersed in nematic liquid crystal (NLC) on electro-optic characteristic and orientation of the LC, we CNT-doped homogeneously-aligned NLC cells driven by in-plane field have been fabricated. The CNTs were aligned with a LC director from the initial state to below critical ac field, whereas the CNTs disturbed the LC director field above critical ac field. We observed motional textures in the form of vertical stripes in the local area between electrodes, which were associated with a deformation of the LC director orientation. This indicates that CNTs start vibrating three dimensionally with translational motion. Further, the hysterisis studies of voltage-dependent transmittance under dc electric field show that the amount of residual dc, which is related to image sticking problem in liquid crystal displays, is greatly reduced due to ion trapping by CNTS while keeping operating voltage and response time about the same compared to the un-doped LC cell.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.1
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• pp.10-18
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• 2000

This paper describes the magnetic orientation of the intact and demembranated bull sperm treated by DTT or heparin in a 5,400 G static field. Semen samples collected from four bulls (Japanese Black) were mixed to the same sperm density. One percentage triton X-100 was used to extract the plasma membrane. The intact and demembranated sperm suspensions were treated with 20, 200, 2,000 mM DTT, 100, 1,000 or 10,000 units heparin solutions at $4{^{\circ}C}$ for 6 days. The decondensation of the sperm nuclei treated by DTT or heparin was examined by measuring the sperm head area at 1, 3, and 6 days. After measuring the area, each sperm sample was exposed to a 5,400 G static magnetic field generated by Nd-Fe-B permanent magnets for 24 hours at room temperature. Results showed that the decondensation of bull sperm nuclei was not induced by the heparin treatment, however, incomplete decondensation was induced by the DTT treatment. During the magnetic orientation, bull sperms treated by DTT or heparin had low percentages of long axis perpendicular to the magnetic lines of force. However, different aspects were obtained for long axis perpendicular orientations following treatment of DTT or heparin. Through the DTT treatment, the decline of long axis perpendicularly oriented percentages was due to the increase of long axis parallel orientation with the head of the flat plane perpendicular to the magnetic lines of force, whereas, using the heparin treatment, the decline of long axis perpendicular orientation was due to the increment of long axis parallel orientation with the head of the flat plane parallel to the magnetic lines of force. Also, percentages of the head of the flat plane perpendicular were decreased by the heparin treatment. These findings suggest that maintaining the structure of protamine in the chromatin is necessary for the sperm head to orient with its flat plane perpendicular, and maintaining the disulfide bond in the chromatin is necessary for the long axis of sperm to orient perpendicularly.

• Polymer(Korea)
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• v.25 no.2
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• pp.240-245
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• 2001

The effect of additives on the orientation of magnetic Sr-ferrite powders has been studied during powder injection molding under applied magnetic field for fabricating multi-pole anisotropic sintered Sr-ferrite magnets. The orientation of the Sr-ferrite powders depends sensitively on the fluidity of powder-binder mixture, related to the binder additives and the injection molding temperature, and the magnetic field intensity. The orientation of Sr-ferrite powders is good for the compacts with stearic acid added in the binder system of paraffin wax/carnauba wax/HDPE, but it is poor for the compacts with silane coupling agent added. The orientation of Sr-ferrites higher than 80% is achieved at the following useful conditions; apparent viscosity lower than 2500 poise in 1000 sec$^{-1}$ shear rate and applied magnetic field higher than 4 kOe.

• Journal of Fashion Business
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• v.14 no.2
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• pp.27-41
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• 2010

The purpose of this study is to investigate the relationship between service orientation of fashion organization and employee's customer orientation. For this study, salespersons in clothing stores were selected as the subjects. We used 4 factors SERV*OR Scale: service leadership, human resource management, employee's empowerment, service system as an organizational service orientation. The results are as follows: First, Service Orientation of the company in fashion field affects the employee's customer orientation. In other words, a fashion company with a higher service orientation will have employees with a higher customer orientation. Second service orientation factors revealed differences depending on the store. Department stores had no effect on factors such as employee's empowerment, service system, but agency stores and outlet stores had effects on all factors. This influential factor is created due to the difference in fashion distribution. Human resource management especially seemed to carry weight among the factors in all stores. So, first and foremost fashion companies should make efforts on education, training of employee.

• Tunnel and Underground Space
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• v.28 no.3
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• pp.193-208
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• 2018

In order to interpret rock slope safely and effectively, the mechanical properties of the rock must be carefully investigated. However, due to the limitations of clinometer usage, a new measure of measurement is required to complement these limitations. In this study, a measuring device was developed to analyze the characteristics of joint orientation, and to apply the orientation of joint to the field. The developed measuring equipment is divided into analysis software and hardware. The hardware was composed of a measuring module that measures the joint orientation of rock and a transport module that transmits the measurement data. The software was developed to analyze the orientation of the joint from the data obtained from the measuring module and is named Drone Joint Orientation Survey Measurement. The developed measuring equipment was well field capable if it could not be measured by the inspector, such as in areas where access was difficult, and was capable of effectively analyzing the lab test results for the orientation of the joint.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.17 no.2
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• pp.105-116
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• 1999

Owing to the rapid development of computer system and the introduction of image processing technique, recent photogrammetric studies have been concentrated on the automation of photogrammetric orientation work that have been carried out by skilled professionals in analog and/or analytical pbotogrammetric field. To automate the whole photogrammetric work, the automation of the orientation processes including interior, relative and absolute orientation should be preceded. This study aims to automate interior orientation and relative orientation process. For this purpose, we applied Hough transform to interior orientation process and object space matching technique to relative orientation process. As the result of this study, we can present a method to automate interior and relative orientation process that has been semi-automatically operated in most commercial digital photogrammetric workstations currently available.