• Title/Summary/Keyword: 이규창

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A Review on VDT Syndrome of Work-Related Musculoskeletal Disorders (작업성 근골격계질환의 VDT 증후군에 관한 고찰)

  • Yang, Young-Ae;Hur, Jin-Gang;Kim, Hyun-Hee;Lee, Gyu-Chang;Lee, Ju-Sang;Jung, Shin-Ho;Ahn, Chang-Sik;Shim, Jae-Hun
    • Journal of Korean Physical Therapy Science
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    • v.11 no.4
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    • pp.20-28
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    • 2004
  • The studys purpose were the effects of work posture, treatment method and prevention for Video Display Terminal(VDT) workers in Work-Related Musculoskeletal Disorders(WMSD) The results were as follows: 1. The prevalence rate of VDT workers in WMSD was $20{\sim}40%$. The complaint was mostly shoulder, neck, and hack area pain 2. VDT worker used to forward flexed posture and then affect of increase of muscle fatigue and pain 3. When exercise therapy PT and ADL training, were used workers decrease in pain, muscle strength, balance training, endurance strength and relief of psychiatricIn conclusion, VDT worker need good health and posture to rest and exercise with time space and treatment. It is best to prevent WMSD. VDT workers need health management by itself and systemic rehabilitation program by speciality therapist.

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Fabrication and Mechanical Properties of TiNi/6061Al Smart Composite by Permanent Mold Casting (금형주조법을 이용한 TiNi/6061Al 지적복합재료의 제조 및 기계적 특성)

  • Kim, Soon-Kook;Lee, Jun-Hee;Yun, Doo-Pyo;Park, Young-Chul;Lee, Gyu-Chang;Kim, Young-Hee
    • Journal of Korea Foundry Society
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    • v.18 no.6
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    • pp.534-540
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    • 1998
  • 6061Al-matrix composite with TiNi shape memory fiber as reinforcement has been fabricated by Permanent Mold Casting to investigate the mechanical properties of the smart composites. The composites have showed good interface bonding as a result of the analysis of SEM and EDX. The smartness of composite is given due to the shape memory effect of the TiNi fiber which generates compressive residual stresses in the matrix material when heated after being prestrained. The tensile strength of the composites was tested at temperatures between $90^{\circ}C$ and room temperature with increasing amount of pre-strain, and it showed that the tensile strength at $90^{\circ}C$ was higher than that of the room temperature. Especially, the tensile strength of the composite increases with increasing pre-strain. It showed that hardness of matrix was higher than that of common 6061Al alloy.

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A Study on Nondestructive Evaluation of Share Memory Alloy Composite at High Temperature (고온에서의 형상기억복합재료의 비파괴평가에 관한 연구)

  • Kang, Dong-Hyun;Lee, Jin-Kyung;Park, Young-Choul;Ku, Hoo-Taek;Lee, Kyu-Chang
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.186-191
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    • 2001
  • Tensile residual stress happen by difference of coefficients of thermal expansion between fiber and matrix is one of the serious problems in metal matrix composite(MMC). In this study, TiNi alloy fiber was used to solve the problem of the tensile residual stress as the reinforced material. TiNi alloy fiber improves the tensile strength of composite by occurring compressive residual stress in matrix using shape memory effect of it. Pre-strain was added to generate compressive residual stress inside TiNi/A16061 shape memory alloy(SMA) composite. It was also evaluated the effect of compressive residual stress corresponding to pre-strains variation and volume fraction of TiNi alloy. AE technique was used to clarify the microscopic damage behavior at high temperature and the effect of pre-strain difference of TiNi/A16061 SMA composite. In addition, two dimensional AE source location technique was applied to inspect the crack initiation and propagation in composite.

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Fabrication and Characterization of TiNi Shape Memory Alloy Fiber Reinforced 6061 Aluminum Matrix Composite by Using Hot Press (핫프레스법에 의한 TiNi/Al6061 형상기억복합재료의 제조 및 기계적 특성에 관한 연구)

  • Park, Dong-Sung;Lee, Jun-Hee;Lee, Guy-Chang;Park, Young-Chul
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.7
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    • pp.1223-1231
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    • 2002
  • Al alloy matrix composite with TiNi shape memory fiber as reinforcement has been fabricated by hot pressing to investigate microstructures and mechanical properties. The analysis of SEM and EDS showed that the composites have shown good interface bonding. The stress-strain behavior of the composites was evaluated at temperatures between 363K and room temperature as a function of prestrain, and it showed that the yield stress at 363K was higher than that of the room temperature. Especially, the yield stress of this composite increases with increasing the amount of prestrain, and it also depends on the volume fraction of fiber and heat treatment. The smartness of the composite is given due to the shape memory effect of the TiNi fiber which generates compressive residual stress in the matrix material when heated after being prestrained. Microstructural observation has revealed that interfacial reactions occur between the matrix and fiber, creating two intermetallic layers.

A Study on the Problems and Improvement of International Factoring System in China (중국 국제팩토링제도의 문제점과 개선방안에 관한 연구)

  • Park, Se Hun;Lee, Gyu Chang;Seo, Kyung
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.59
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    • pp.159-178
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    • 2013
  • International factoring is very useful to transfer credit risk, to promote cash flow, to collect debt and to reduce cost and expenses. However, International factoring system in china shows imperfection especially in gap of legal vacuum and its limit to be developed. Here I suggest a practical alternative for development of International factoring system in china as follow. First, legal environment in China for factoring system should be rearranged. Even law and contract law have relative clauses for factoring system there are many difficulty to be applied. It is necessary to prepare legal ground for factoring system. Second, without recourse for International factoring system should be fixed. Without recourse is the essential point for factoring system in international trade. In fact chinese factors are partially applied only for those big global companies. However International factoring system is especially useful for small-medium companies lacked of a good credit rating. It is necessary to promote special factors by combining financial organizations as it does in developed countries. Third, they need to make legal ground to prohibit unlicensed factoring companies. Forth, they need to educate usefulness of factoring system. The settlement system in China is to be developed by systematic researches and promotion for International factoring system.

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Remanufacturing Industry for Automobile Parts of USA (미국의 재제조산업에 관한 연구)

  • Mok, Hak-Soo;Jeon, Chang-Su;Han, Chang-Hyo;Skerlos, Steven J.;Kim, Hyung-Ju;Lee, Kyu-Chang
    • Journal of the Korean Society for Precision Engineering
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    • v.27 no.3
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    • pp.58-65
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    • 2010
  • Remanufacturing is a process that restores old products to perform like new, while saving energy, reducing consumption of natural resources, and lowering environmental emissions. By extending the product life cycle, remanufacturing approaches enable closed loop material cycles that are ultimately necessary for a sustainable society. This paper provides some description of the current automotive remanufacturing enterprise, with a particular emphasis on key vehicle components that are currently remanufactured. The analysis yields two major conclusions. First, volume of the USA automotive after sales and remanufacturing industry market is estimated. Second, market price of a remanufactured component in the automotive sector is surprisingly uncorrelated with the number of companies engaged in remanufacturing that component - at least for companies registered with the Automotive Parts Remanufacturing Association (ARPA).

The Influence of Neck Pain on Balance in Young People (젊은 사람의 목 통증이 균형에 미치는 영향)

  • Lee, Gyu-Chang
    • Journal of the Korean Society of Physical Medicine
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    • v.7 no.4
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    • pp.423-432
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    • 2012
  • PURPOSE: The purpose of this study was to investigate balance changes in young patients with neck pain by comparing postural sway velocity and velocity moment between young patients with neck pain and healthy subjects. METHODS: The cross-sectional study enrolled fifteen young patients with over 3-month duration of the neck pain and twelve healthy subjects between the ages of 20 and 30 years old. All subjects were measured their postural sway velocity and velocity moment during quiet standing with eyes open and eyes closed conditions. We compared the differences of postural sway velocity and velocity moment between neck pain patients and healthy subjects, and between eye open and eye close. RESULTS: Significant differences were evident in the anteroposterior and mediolateral sway velocity, and velocity moment of center-of-pressure (COP) between patients with neck pain and healthy subjects (p<.05), and in patients with neck pain in the eyes open and eyes closed conditions (p<.05). CONCLUSION: These results indicate that the balance of young patients with neck pain was worse than healthy subjects during quiet standing, and was especially lessened in the absence of vision. The finding may inform management program to decrease the balance deficits in young patients with neck pain.

Fracture Characteristic of TiNi/A16061 Share Memory Alloy Composite at High Temperature using Acoustic Emission Technique (AE 기법을 이용한 TiNi/A16061 형상기억복합재료의 고온파괴특성평가)

  • Lee, Jin-Kyung;Park, Young-Choul;Kang, Dong-Hyun;Park, Dong-Sung;Lee, Kyu-Chang
    • Proceedings of the KSME Conference
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    • 2001.06a
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    • pp.72-77
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    • 2001
  • Tensile residual stress happen by difference of coefficients of thermal expansion between fiber and matrix is one of the serious problems in metal matrix composite(MMC). In this study, TiNi fiber was used to solve the tensile residual stress as the reinforced material. TiNi fiber improves the tensile strength of composite by occurring compressive residual stress in matrix using shape memory effect of it. Pre-strain was added to generate compressive residual stress inside TiNi/A16061 composite. It was also evaluated the effect of compressive residual stress corresponding to pre-strains variation. AE technique was used to clarify the microscopic damage behavior at high temperature and the effect of pre-strain difference of TiNi/A16061 shape memory alloy composite.

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Study on Automation of Integrated Seedling Production System - Planting Device- (종합공동육묘장의 설비 자동화에 관한 연구 -파종시스템-)

  • 최창현;노광모;이규창;김재민
    • Journal of Biosystems Engineering
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    • v.21 no.2
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    • pp.123-133
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    • 1996
  • An automatic drum seeder was developed to improve the seeding operation. It consisted of a conveyor to transfer seedling trays, a seed-hopper to supply seeds, a drum to drop seeds on the tray, and an air blower to remove extra seeds. A photo sensor was used to detect the transfer of seedling trays, and its signal was fed into microcomputer which operated a stepping motor driving the drum. The seeds were adhered to the surface of drum by vacuum pressure, and were dropped into tray cells by compressed air. An air connection unit was devised to alternate between vacuum pressure and compressed air. A control program for the system, written in C language, could operate the drum at the given number of revolutions and revolutions per minute. The results showed that the air connection unit could operate well and the seeds were dropped satisfactorily into tray cells. In case of cabbage and perilla seeds, which are regular and spherical shape, the missing rate was low and the single seeding rate was more than 97%. Low missing rate and high multiple seeding rate were observed in lettuce seeds which have narrow ends with tight weight. The missing rate of pepper seed was very high because of heavy weight and irregular shape. To improve the performance of the seeder, adjustment of vacuum pressure based upon shape and weight of the seeds, careful selection of the material of drum, maintenance of consistent air blower pressure, and replacement of stepping motor to DC motor are recommended.

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Ultrastructural Studies of the Brain Tumors (뇌종양세포의 미세형태학적 연구)

  • Deung, Young-Kun;Kim, Chung-Sook;Lee, Kyu-Chang;Lee, Hun-Jae
    • Applied Microscopy
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    • v.9 no.1
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    • pp.35-56
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    • 1979
  • To investigate ultrastructural characteristics of cancer cells of the nervous system, 25 cases; i.e. astrocytoma(9), oligodendroglioma(1), medulloblastoma(1), meningioma(5), pinealoma(2) and pituitary adenomas(7). The common findings were marked irregularity of nuclear membrane with pronounced infoldings, clumping of heterochromatin along inner nuclear membrane, enlargement of nucleolus, and frequent observations of nuclear bodies and nuclear inclusions. But these findings are also the signs that can be observed in hyperactive cells. Thus, ultrastructural characteristics of cancerous nucleus are the great variability of nuclear size, shape and composition. but none of them appear to be specific. Among cytoplasmic organelles, massive fibrils are characteristic of astrocytoma and meningiomas, cytoplasmic protofibrils such as glial process and microvesicles in oligodendroglioma, secretory granules are characteristic in pituitary adenomas, and fine filamentous fibrils and desmosomes are characteristic of fibroblastic type of meningioma. Intercellular relationships and cell membrane specialization are important features in the differential diagnosis of various undifferentiated tumors. The frequent resolution of difficult diagnosis problems by electron microscopy outweighs the disadvantages of this technique, such as the expense and time required.

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