• Journal of Biomedical Engineering Research
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• v.15 no.3
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• pp.289-294
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• 1994

A new type of electrogoniometer to measure the three dimensional motion of the human knee joint was developed. This instrument is composed of six potentiometers: four arranged for two universal joints, one for pin joint, and one for axial rotation measurement. The voltage change in six potentiometers were collected through A/D converter for acquisition, storage and analysis. With a developed instrument, gait analysis was performed. Compared to earlier developed triaxial type goniometer, new instrument shows its convenience in application and accuracy in measurement.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.3
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• pp.421-430
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• 2010

This work describes a derivation process of JIC(Joint Integrating Concept) based JFC(Joint Functional Concept) analysis of an Aegis BMD(Ballistic Missile Defense). JIC is developed through JOC(Joint Operating Concept) and JFC based on capstone strategy and concept. Aegis BMD is a sea-based ballistic missile defense to detect ballistic missile threat, increase engagement battlespace and enable multiple engagement based on Aegis ships. Aegis BMD is a good case of JIC due to performing an Joint operations based on System of Systems under highly complicated NCW environment. This work analyses JFC using QFD(Quality Function Deployment) and UJTL(Universal Joint Task List). From this analysis the JIC of Aegis Korean BMD is derived using a CASE tool.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.15 no.1
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• pp.1-8
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• 2009

Purpose: The purposes of this study were to establish the concurrent validity of the universal goniometer and electronic inclinometer for ankle joint of motion, and to determine the inter-tester and the intra-tester reliability of these two instruments. Methods: Subjects were instructed 25 healthy subjects. Ankle range of motion was measured on two separate occasions 2 or 3 days by two physical therapists. Ankle dorsiflexion and plantarflexion was by using an universal goniometer and an electronic inclinometer. Results: The Pearson product-moment correlation between the two instruments was 0.78~0.80. The ICCs for inter-tester reliability ranged from 0.63 to 0.73 for universal goniometer and ranged from 0.81 to 0.88 for electric inclinometer. The ICCs for intra-tester reliability showed a wide variation(ICC=0.61 to 0.86). Conclusion: These findings indicate that the two instruments are reliable instruments for measuring ankle joint range of motion. The results also indicate that the two instruments can be used interchangeably for measuring ankle motions.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2009.04a
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• pp.417-420
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• 2009

본 논문에서는 유니버설 조인트의 기구학적인 해석을 위하여 원동축이 평면 내에 존재할 경우와 그렇지 않은 경우에 대하여 종동축의 속도를 관찰하였다. 평면 내의 경우는 기존 이론값과 동일하나 평면 외의 경우는 유한회전의 순서에 따라서 독립적인 결과값을 가지게 된다. 이는 오일러 각의 순서를 달리하면 표현되는 속도가 다르기 때문이며 이러한 단점을 극복하기 위하여 원동축에 4원법을 적용하였다. 수치 예제를 통하여 기존의 방법과 제시한 방법을 비교하여 제시한 방법이 일관성 있는 결과를 제공함을 확인하였다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.1
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• pp.89-97
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• 2001

In this paper, we present a new two-dof anthropomorphic joint mechanism that enables to mimic the humanlike motion. The proposed mechanism, called Double Active Universal Joint(DAUJ), generates a two-dof swivel motion without rolling by the coupled motion of two independent motor. In addition, we perform basic experiments to confirm the effectiveness of the proposed mechanism and the results are reported.

• Journal of KSNVE
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• v.2 no.2
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• pp.125-134
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• 1992

In this study, ti identify the dynamic characteristics of automobile steering system which consists of many components and joints, each component combined structure was analyzed using commercial structural package, ANSYS. And, the finite element method for each component and modeling method of several joints universal joint, bolt joint, bearing, etc. were studied. On the other hand, the experimental modal analysis was performed to compare with the results of the finite element analysis and joint modeling. The result shows very close agreement between two analysis. Also, it was found that the steeing column used in this experiment does not effect the low frequency mode of entire system. In addition, we found that constraint equations need to be considered in modeling universal joint. Since the stiffness effect of Urethane around wheel could be ignored, it can be modeled only with mass effect. In the end, it was found that dynamic characteristics of the entire steerintg system depends mainly upon the wheel characteristics.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.9
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• pp.982-989
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• 2009

Parallel Kinematic Mechanism (PKM) is a device to perform the various motion in three-dimensional space and it calls for six degree of freedom. For example, Parallel Kinematic Mechanism is applied to machine tools, medical equipments, MEMS, virtual reality devices and flight motion simulators. Recently, many companies have tried to develop new Parallel Kinematic Mechanism in order to improve the cycle time and the precisional tolerance. Parallel Kinematic Mechanism uses general universal joint and spherical joint, but such joints have accumulated tolerance problems. Therefore, it causes position control problem and dramatically life time reduction. This paper focused on the rolling element to improve sliding precision in new sliding ball joint development. Before the final design and production, it was confirmed that new sliding ball joint held a higher load and a good geometrical structure. FEM analysis showed a favorable agreement with tensile and compressive testing results by universal testing machine. In conclusions, a new sliding ball joint has been developed to solve a problem of accumulated tolerance and verified using tensile and compressive testing as well as FEM analysis.

• Journal of Veterinary Clinics
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• v.34 no.4
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• pp.241-244
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• 2017

The purpose of this study was to evaluate the concurrent validity of the double meter inclinometer (DMI) for passive joint range of motion (ROM) in beagle dogs and to compare these results to a universal plastic goniometer (UPG). Fifteen beagle dogs were recruited for this study. Joint ROM was evaluated twice with each device to calculate the intraobserver reliability. The intraclass correlation coefficient (ICC) values of the UPG were good to excellent (> 0.75) for all joint ROM tests. Similar results were obtained with the DMI. The ICC values of the DMI were good to excellent (> 0.75) except in extension of the tarsal joint (ICC = 0.69). The majority of the ICC results between each device were poor (< 0.50) with the exception of six joints. Our findings suggest that the inclinometer can be used for passive joint ROM in veterinary medicine. However, caution should be taken when comparing measured values of passive joint ROM obtained utilizing both the DMI and UPG.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.4
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• pp.213-219
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• 2018

Mechanical components are to be produced with accurate dimensions in order to function properly in assemblies of a machine. Once designs of mechanical components are created, designers examine the designs by adopting many known experimental methods. A primary test method includes stress and strain evaluation of structural parts. In addition, fatigue test and vibration analysis are an important test method for mechanical components. Real experiments at a laboratory are established when products are manufactured. Since design changes should be done before producing the designs in factories, rapid modifications for new designs are required in production industries. FEM simulation is a proper choice for a design evaluation with speed at a detail stage in design process. This research focuses modeling and mechanical simulation of a mechanical component in order to ensure structural safety. In this paper, a universal joint, being used in driving axels of vehicles, is studied as a target component. A design model is created and tested in some ways by using commercial software of FEM. The designed component is being twisted to transmit heavy power and thus, torsional stress should be under strengths of the component's material. The next is fatigue analysis to convince fatigue cycles to be within the endurance limit of the material. Another test is a vibration analysis for rotational components. This research draws final conclusions from these test analyses and recommends whether the designed model is under safety condition in terms of mechanical structure.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.672-675
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• 2000

There are many sources of errors in the parallel device. This study investigates the effect of a clearance error at a U-joint on the position and orientation errors of the platform of a new parallel device, cubic parallel manipulator. In this study, the limits of errors can be estimated for given conditions.