Effect of Platelet-Rich Fibrin on Repair of Defect in the Articular Disc in Rabbit Temporomandibular Joint by Platelet-Rich Fibrin

( Hyun Su Baek ),( Hye Sung Lee ),( Bok Joo Kim ),( In Kyo Chung ),( Chul Hoon Kim ),( Sun Mi Jin ),( Hie Sung Hwang ),( Sang Hun Shin2 ) 한국조직공학·재생의학회 2011 조직공학과 재생의학 Vol.8 No.6

The objective of this study was to evaluate platelet-rich fibrin (PRF)’s effectiveness in repairing articular disc defect in the temporomandibular joint (TMJ) of rabbits. Eight rabbits were divided into four groups of two rabbits each, corresponding to groups A, B, C, and D. Both TMJs of all of the rabbits were used in the experiments: the right joints comprised the experimental groups, and the left ones, the control groups. The disc defect was circular and 2 mm in diameter. In the experimental groups, the PRF was compressed into the defect, whereas the control group defects were left untreated. A, B, C, and D groups were sacrificed at the 1st, 2nd, 4th and 6th weeks, respectively. The defects of each control group exhibited no specific changes. Contrastingly, in each experimental group, there was an increased number of chondroblasts at the margins of the defects, along with accelerated cell differentiation and a columnar cell arrangement observable at the time of cell differentiation. The experimental groups showed inflammatory cell infiltrations and fibrosis by the 1st week, maturation of chondrocytes by the 2nd week, and proliferation by the 4th week, after which the defects began to be filled with chondrocytes, a process that was complete after the 6th week. In the histological evaluation (H-E), the experimental groups showed significant increases of chondroblasts after the 2nd and 4th weeks, as well as regular columns of chondrocyte arrays observable during cell division. After 6 weeks, the defects were filled with chondrocytes.

커패시터 放電 임펄스 着磁機 및 着磁 요크시스템의 定數算定에 관한 硏究

白壽鉉,金 龍,金必洙,尹秀鳳,朴永浩,尹信容 동국대학교 대학원 1992 大學院硏究論集-東國大學校 大學院 Vol.22 No.-

In a capacitor-discharge impulse magnetizer, a magnet is magnetized by the discharging current of capacitor The actual construction of magnetizing fixtures and discharge matching is expensive and time-consuming. Since the parameters of the impulse magnetizer have been determined and the resistance and inductance of such a magnetizing fixture can be easily computed using FEA, it is possible to predict the performance of such a fixture without actually building it. This paper describes that by mathematically modeling the capacitor-discharge impulse magnetizer fixture the problem can be solved with resonable predictability. The basic equations are presented and used to predict the magnetic-field intensity inside the fixtures. Finite-Element-Analysis is also used as part of the design process

복잡한 지하구조 해석을 위한 물리탐사 자료 분석에 관한 연구

신득현,김훈,오석훈,서백수 江原大學校 産業技術硏究所 2007 産業技術硏究 Vol.27 No.B

Currently, geophysical method is applied for understanding the subsurface geologic structure economically and systematically, but there exists some limitations on recognizing complex subsurface structures precisely by a single geophysical method. In order to understand the complex subsurface structures, we applied various geophysical methods including seismic refraction survey, two-dimensional resistivity survey, seismic tomography survey, suspenaion-ps log, and understood distribution of low velocity, low resistivity range of resistivity survey and correlation of an intersecting point, velocity distribution of seismic tomography survey.

암환자에서 다른 신경학적 증상이 동반되지 않는 두통 : 예비 보고

이성형,안미영,백신혜,이형석,신동익,이상수 충북대학교 의과대학 충북대학교 의학연구소 2010 忠北醫大學術誌 Vol.20 No.1

연구목적 : 암환자에서 신경학적 결손이나 발작 등이 동반되지 않는 두통의 원인과 이런 경우 심각한 두개내 질환에 의한 이차두통을 의심할 수 있는 소견의 진단적 유용성을 알아보고자 하였다. 대상 및 방법 : 2005년 10월부터 2009년 1월까지 신경학적 결손이나 발작을 동반하지 않는 두통이 발생한 71명의 암환자를 대상으로 하였다. 자세한 병력을 청취하고 신경학적 검사를 하였으며, 환자의 상황에 따라 적절한 조합의 뇌MRI, 뇌CT, 및 뇌척수액 검사를 시행하였고, 최소한 3개월 이상 추적 관찰하였다. 이 소견을 종합하여 두통의 국제분류 기준(The International Classification of Headache Disorders, second edition) 에 따라 두통을 진단하였다. 또한 심각한 두개내 질환에 의한 이차두통을 의심할 수 있는 소견인 있는 환자군과 없는 환자군 사이에 중추신경계로의 전이빈도가 차이가 나는지 알아보았다. 결과 : 71명 중에 8.5%인 6명에서 중추신경계로의 전이가 관찰되었는데 심각한 두개내 질환에 의한 이차두통을 의삼할 수 있는 소견이 있었던 18명 중에 4명(22.2%), 이런 소견이 없었던 53명 중에 2명(3.8%)이었다. (상대위험도 5.89, 95% 신뢰구간 1.18-29.49). 두통의 다른 원인으로는 지주막하 출혈이 1명, 중추신경계 이외의 감염에 의한 두통이 6명, 항암제에 의한 두통이 1명, 고혈압성 두통이 1명, 방사선 치료와 관련된 두통이 1명, 원발성 찌름두통이 3명, 긴장성 두통이 51명이었다. 결론 : 심각한 두개내 질환에 의한 이차두통을 의심할 수 있는 소견의 유무가 암환자에서 발생하는 두통의 감별진단에 유용하며, 이러한 소견이 동반되지 않는 경우의 두통은 대부분 양성이다. 하지만 이러한 결론을 바탕으로 향후 보다 많은 대상 환자군을 통한 연구가 필요할 것이다. Purpose: Headache in patients with systemic malignancy is a great concern to neurologists. We performed this study to investigate the frequency of metastasis as the cause of headache in the patients with systemic malignancy and the usefulness of symptoms suggesting underlying serious pathologies especially when headaches do not accompany any other neurological symptoms. Materials and Methods: From October 2005 to January 2009, we prospectively collected 71 patients with systemic malignancy complaining headache but not having any other accompanying neurological symptoms. After thorough history taking and neurological examination, we performed a neuroimaging (MRI or CT) and CSF study according to the clinical situations of individual patients and followed them at least 3 months and diagnosed headaches according to The International Classification of Headache Disorders, second edition (ICHD-II). We compared the incidence of intracranial metastasis between headaches with symptoms suggesting underlying serious illness and those without. Results: Six (8.5%) out of 71 patients had intracranial metastasis: 4(22.2%) out of 18 patients with symptoms suggesting underlying serious illness, 2(3.8%) out of 53 patients without them (relative risk 5.89, 95% confidence interval 1.18-29.49). Other causes included subarachnoid hemorrhage (1 patient), headache attributed to infection (6), headache attributed to drug (2), hypertensive headache (1), headache attributed to radiotherapy (1), primary stabbing headache (3), and tension headache (51). Conclusion: This study suggests that headache symptoms suggesting underlying serious disorder are valuable in differentiating the causes of headache without any other accompanying neurological symptoms in patients with systemic malignancy and headaches without those symptoms might be usually benign. However, more broad study should be made for these value and relationship.

품질경영 발전단계에 따른 R&D 활동의 성과에 관한 연구

김신중,백종현 대진대학교 2000 大眞論叢 Vol.8 No.-

In recent, many companies seek competitive power by technological advantage through R&D. However, many new expected products have been failed in market or troubled in production. It is problem to misunderstand customer' needs and use unadaptable technology due to non-effective R&D management. In these situation, TQM is being suggested as an alternative for effective R&D management. The specific purpose of this study could be summarized as follow: First, the perceived level of TQM in R&D of domestic companies was investigated. Second, the adaptability of TQM development theory in R&D was analyzed in previous literature review. Third, the correlation between TQM variables and R&D performance was analyzed. The major findings of this study can be summarized as follow: TQM is an adaptable method for R&D result transferable to commercial application by considering quality through perceiving and gathering external nd internal customer needs in the beginning stage of R&D. TQM development theory in R&D will provide not only a checklist for what needs to be done, but also a framework for how things should be done.

슬라이딩 모드를 이용한 LDM 서보밸브의 추종제어

윤신용,백수현 동국대학교 산업기술연구원 1999 산업기술논문집 Vol.13 No.-

본 논문은 LDM을 이용한 직접구동 서보밸브의 위치 추종제어를 연구하였다. 선형 전자석 솔레노이드로 구동되는 노즐 플레퍼형 서보밸브와 비례 선형 밸브는 공장 자동화 분야에 광범위하게 적용된다. 이러한 고전적인 서보밸브는 효율, 오염, 저속에서 문제점을 지니고 있기 때문에, 고속 및 고정밀 서보밸브가 요구된다. 따라서 본 연구에서는 LDM을 이용한 고속 하이드라릭 서보밸브를 적용한다. 제어는 슬라이딩 모드인 새로운 형태의 상태 공간 궤적을 이용한다. 가변구조시스템 (슬라이딩모드)은 적합한 스위칭 로직과 함께 연속적 특성을 갖는 종속시스템으로 가변구조시스템을 구성하고 있다. 따라서 본 연구에서는 슬라이딩모드 제어기법을 이용한 최적의 성능을 갖는 시스템을 제안한다. This paper deals with a position sliding mode control of direct drive hydraulic servo valve(linear servo valve, LSV) using linear DC motor (LDM). The nozzle-flapper type servo valves and proportional linear valves driven linear electromagnetic solenoid are widely used in factory automation. Because these conventional valves involve problems in efficiency, contamination and low-speed. High speed and hi precision servo valves have been required. This paper is applied to high speed hydraulic servo valve using LDM. The controller is designed so that a new type of state space trajectories called sliding mode exists. Variable structure system (sliding mode) consist of a set of continuous subsystems together with suitable switching logic. Therefore, a sliding mode control has the control performance very near to the time optimal one.

출력 피드백제어 시스템을 위한 적응 관측제어기

윤신용,백수현,김용 동국대학교 대학원 1999 大學院硏究論集-東國大學校 大學院 Vol.29 No.-

Adaptive control is one of the ideas conceived in the 1950's which has firmly remained in the mainstream of research activity with hundreds of papers., One of the reasons for the rapid growth and continuing popularity of adaptive control is its clearly defined goal : to control plants with unknown parameters. Adaptive control has been most successful for plant moduls in which the unknown parameters appear linearly. Adaptive backstopping and turning functions produces are Lyaunove-based design. A common approach to output feedback control of linear system is to use the certainty equivalence principle and combine state-feedback controller with the estimators (observers). In this paper we designed the modular of output feedback control system, the output feedback modular approach results in separation of two design modules : observer based scheme, swapping based scheme. We design output-feedback control laws which guarantee input-to-state stability with respect to the parameter error, its derivative, and the state estimation error as the inputs. The schemes in the paper are simpler than the tuning functions schemes because they do not eliminate angle error θ for the error system.

Expansin으로 형질전환 된 담배의 생장 특성

신하정, 성현정, 백승준, 김보미, 엄유리, 조은정, 정찬문, 이이 충북대학교 연초연구소 2008 煙草硏究 Vol.21 No.-

-본문참고-

결절종으로 초래된 후방골간신경 마비: 증례보고

신재원, 백신혜, 이형석, 신동익, 이성현, 이상수, 김지선 충북대학교 의과대학 충북대학교 의학연구소 2011 忠北醫大學術誌 Vol.21 No.2

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링형 초음파모터의 고정자 진동 해석 및 구동회로 개발

박기준,백수현,김용,윤신용,김일남 동국대학교 산업기술연구원 1999 산업기술논문집 Vol.14 No.-

본 논문에서는 링형 초음파 모터의 고정자의 굽힘진동에 대한 일반적인 해석에 대해 기술하였다. 전기-기계 결합효과를 고려하여 일반화 응력과 변형의 개념을 정립하였고, 일반화 압전방정식, 일반화 응력과 변형의 관계, 미분운동방정식에 대해 기술하였다. 또한 고정자의 진동모드 계산과 공진주파수를 계산하기 위해 유한요소법을 적용하였으며, 유한요소법을 이용한 진동해석 프로그램인 ATILA를 사용하여 고정자의 공진주파수와 변위를 계산하였다. 초음파 모터의 구동을 위해 20kHz 이상의 고주파 전원이 필요하기 때문에 2상 병렬 공진형 인버터를 제작하여 구동전압의 주파수 및 크기를 측정하여 고정자 해석과 구동회로 시뮬레이션과 비교하였다. In this paper, the bending vibration analysis of the stator for a ring type ultrasonic motor is described. Considering the electromechanical coupling effect, the concepts of generalized stress and strain are explained in detail using the generalized piezoelectric equations, which is the relationship between generalized stress and strain, the differential motion equation were derived. The vibration modes and resonance frequencies of the stator were calculated using the finite element code ATILA. For driving of ultrasonic motor, a two-phase parallel-resonant inverter was made. The stator analysis results and driving circuit simulation results are compared with measured frequencies and amplitudes.