• 대한관절경학회지
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• 제8권2호
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• pp.89-93
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• 2004

목적: 신선 동결된 동종 경골건(tibialis tendon)을 이용한 관절경적 전방 십자 인대 재건술 후 추시가 가능하였던 예에 대하여 슬관절의 안정성과 기능적 결과 등을 분석하여 보고하고자 하였다. 재료 및 방법: 2002년 7월부터 2003년 6월까지 전방 십자 인대 손상으로 신선 동결된 동종 경골건을 이용하여 재건술을 시행하고 1년 이상 추시가 가능하였던 31 례를 대상으로 하였다. 술후 슬관절의 안정성 평가를 위해 주관적 검사로 Lysholm knee score 및 2000 International Knee Documentation Committee(IKDC) subjective knee score를 이용하였으며 객관적 검사로 Lachman 검사, pivot shift 검사와 KT-1000 arthrometer 검사상 환측과 건측의 최대 전방 전위 차이 및 2000 IKDC슬관절 검사를 이용하였다. 결과: 최종 추시점에서 주관적 검사로 Lysholm score는 평균 띨점 이었고, 양호 이상은 28 fl(90.3%) 였다. IKDC subjective knee score는 70점 이상이 27 례(87 1%) 였다. 객관적 검사로 Lachman검사상 1+에 firmend-point 이하의 전방 전위를 보인 경우가 30 at(96.8%) 이었고 pivot shift검사는 음성인 경우가 27 례(87 1%) 이었다. KT-1000 arthrometer 검사상 환측과 건측의 최대 전방 전위 차이는 평균 3.1 mm였고 5 mm이하의 전위를 보인 경우가 30 at(96.8%) 였다. IKDC슬관절 검사 상 정상 혹은 거의 정상 소견을 보이는 경우가29례(93.5%) 였다. 최종 추시 결과 합병증으로 이식물 실패로 의심되는 경우가 1례, 감염 1례가 있었다. 결론: 두 겹의 동종 경골건을 이용하여 관절경적 전방 십자 인대 재건술을 시행하고 단기 추시 결과 비교적 양호한 결과를 얻었으며 추후 중장기적 추시가 필요하리라 생각된다.

• 대한견주관절학회:학술대회논문집
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• 대한견주관절학회 2003년도 연수강좌
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• pp.51-56
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• 2003

The trained examiner can gain considerable information from visual inspections of the elbow joint, Because much of the joint is subcutaneous, any appreciable alteration in the skeletal anatomy often is detectable. Gross soft tissue swelling or muscle atrophy is also early observed. Inspection and palpation of the medial and lateral epicondyles and the tip of the otecranon from an equilateral triangle with the elbow is flexed. Normally, the arc of flexion extension, although variable, ranges from about O to 140 degrees plus or minus 10 degrees. The posterolateral rotatory instability(PLRI) of the elbow is most common pattern of elbow instability. The lateral collateral ligament complex also includes a narrow but stout band of ligamentous tissue blending with the distal and proterior fibers of the capsule to insert distally on the crista supinatoris of the ulna. This is the lateral ulnar collateral ligament(LUCL). A clinical elbow pivot shift test confirms the PLRI. There are also two active apprehension signs.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2635-2643
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• 2011

Current freight electric locomotives (132 ton) of the eco-friendly and can carry large cargo logistics as a means of generation has increased the demand at home and abroad. Especially, Freight electric locomotives to increase the traction, it is easy to mass and rapid transport. In addition, Freight electric locomotives is no exhaust and low noise compared to diesel -electric locomotives and it can be eco-friendly transportation. CO_CO BOGIE of Freight electric locomotives has no the center pivot and Traction_Rod and Spring of CO_CO BOGIE is mounted on the body. These freight electric locomotives to be satisfied with the safety regulations. Carbody development satisfied Implementation of optimum body and collision is the focus. Accordingly, the different approach in the upper and lower carbody structure and interior and equipment placement is needed. On this paper, the contents give explanation of cases on carbody design composed of freight electric locomotives now developed and process of improvement by structure analysis and collision analysis.

• 한국소음진동공학회논문집
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• 제26권2호
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• pp.187-194
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• 2016

Parametric study on the lever type dynamic anti-resonance vibration isolator (DAVI) is executed to introduce the system in the path of vibration transmission for the vibratory response attenuation. The effects of inertia and location of the lever on the system performances are investigated using FEA. The effects of other parameters such as ratio of lever lengths, ratio of masses and the location of pivot are studied with analytical approach. According to the results, all the parameters except lever location affect the system response in their own ways. Consequently, the optimal lever type DAVI for translational or rotational system can be efficiently designed by selecting system parameters using the procedure introduced in this study.

• 항공우주시스템공학회지
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• 제4권2호
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• pp.21-25
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• 2010

Fatigue properties of composite materials are extremely important to design durable and reliable helicopter rotor blades. However, it is very difficult to apply conventional fatigue test loads in short period. Therefore, accelerating test speed and facilitating spectrum load realization are required. In this study, we have developed a fatigue testing method that uses a resonance of simply supported beam type blade specimen. This test consists in exciting the blade specimen with a frequency that corresponds to its natural frequency. In that case, the test specimen similar to a beam fixed between two pivot points starts vibrating and is significantly deformed. Resonant fatigue tests were performed by changing exciting vertical amplitude and frequency, and S-N curves of each composite materials were successfully obtained.

• 대한기계학회논문집B
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• 제28권10호
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• pp.1238-1246
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• 2004

Momentum exchange theory has been generally used for an analysis of the regenerative turbomachines due to its direct description of the complicate circulatory flow. However, because its application is limited only to linear region and its model equations are incomplete on three variables, it needs further refinements. In the present study it is improved by introducing a central pivot of circulatory flow. Also, by assuming linear circulatory velocity distribution, mean radii of inlet and outlet flows through the impeller are newly suggested. By applying control volume analysis to both linear region and the acceleration region, the governing equation on the circulatory velocity is derived. As a result, systematic performance analysis on the entire region of the incompressible regenerative turbomachines can be carried out based on the proposed model equations.

• 한국자동차공학회논문집
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• 제4권6호
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• pp.97-108
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• 1996

A modeling technique is proposed for dynamic simulations of OHC valve trains with HLA(hydraulic lash adiuster). HLA is expressed by an air-oil mixture model considering HLA leak-down and aeraton effects. A compact nonlinear equation is derived which describe the short term dynamic behavior of the HLA. Valve spring is analyzed by a distributed parameter model including nonlinear characteristics in the spring surge phenomena. Global behavior of the remaining valve train is expressed by a lumped mass model. The experiental results prove that the simulation model developed here is accurate and useful for the dynamic simulations of OHC valve trains with HLA.

• 항공우주기술
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• 제9권2호
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• pp.1-7
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• 2010

Fatigue properties of composite materials are extremely important to design durable and reliable helicopter rotor blades. However, it is very difficult to apply conventional fatigue test loads in short period. Therefore, accelerating test speed and facilitating spectrum load realization are required. In this study, we have developed a fatigue testing method that uses a resonance of simply supported beam type blade specimen. This test consists in exciting the blade specimen with a frequency that corresponds to its natural frequency. In that case, the test specimen similar to a beam fixed between two pivot points starts vibrating and is significantly deformed. Resonant fatigue tests were performed by changing exciting vertical amplitude and frequency, and S-N curves of each composite materials were successfully obtained.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1993년도 추계학술대회 논문집
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• pp.475-481
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• 1993

The objective of this study is to develope the reliability prediction model for Float Rated Integrating Gyroscope( :FRIG) at maximum loading. The equation of motion for FRIG is firstly derived to set up the reliability prediction model. To analysis reliability or all parts of the gyro is not easy due to their complicated structure. Therefore the failure parts are chosen by Failure Mode Effective Analysis (:FMEA). F.E.M is utilized to calculate loads for the selseced rotating assembly and pivot / jewel. The technical reliability is calculated by applying reliability design theory with these results and the performance reliability is sought through distribution estimation with error test data. The bulk reliability of gyroscope is sought by applying the two results. The present prediction results are compared with the accumulation time in good agreement.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1273-1276
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• 2005

A displacement magnification mechanism is usually employed in a nano-positioning stage to achieve a large stage motion. A lever mechanism is the most widely used displacement magnifying mechanism. For more large stage motion, double or multiple lever mechanisms can be used. In this case, a more accurate analysis model is needed. This study proposes a more reasonable analysis model for a multiple lever mechanism based on the single lever mechanism model. This paper describes that the high equivalent stiffness of the lever is the most important factor reducing the magnification ratio of the lever mechanism through increasing the deflection of the link and including the axial displacement of the pivot.