• Journal of Oral Medicine and Pain
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• 제25권1호
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• pp.73-85
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• 2000

The purposes of the study were (1) to see if there are various types of disc configuration in normal temporomandibular joint and, if so, (2) to examine whether a specific type of disc configuration is susceptible to disc displacement, and (3) to see if a specific type of disc configuration and position is related to early relief of clinical symptoms from the anterior disc displacement without reduction to conservative treatment. From the magnetic resonance (MR) images taken for the patients with symptoms of temporomandibular disorders, 235 images as normal joint group, 255 images as anterior disc displacement with reduction group, and 249 images as anterior disc displacement without reduction group were selected, After the TMJ image was scanned and processed with Photoshop program, the disc configuration was determined, The incidence of various types of disc configuration was analyzed according to age, sex, diagnostic group, and the promptness of symptom relief. The disc position was also examined in relation to the promptness of symptom relief. The results were as follows : 1. In the normal joint group, biconcave type appeared most frequently and reversed, biplanar type in order, Posterior band enlarged and folded type didn't appear at all. On the other hand, in the anterior disc displacement without reduction group, folded type appeared most frequently and also posterior band enlarged type were found often. 2. There were statistically significant differences between sex and configuration of disc in the normal joint group and no statistically significant differences in the anterior disc displacement with reduction group and anterior disc displacement without reduction group, 3. There were no statistically significant differences between age and configuration of disc in the normal, anterior disc displacement with reduction group and anterior disc displacement without reduction group. 4. In anterior disc displacement without reduction group, rapid response was observed in biconcave and reversed type and delayed response was observed in folded type.

• Earthquakes and Structures
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• 제25권3호
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• pp.149-160
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• 2023

Over the course of the last 4-5 years, India's northeastern region have widely used Autoclaved Aerated Concrete (AAC) blocks to construct load-bearing masonry structures. The aim of this investigation is to examine the shear characteristics of AAC masonry triplet assemblage strengthened by using two techniques, i.e., the bead joint (BJ) and the bed-head joint (BHJ) technique. Three unique variations of wire mesh were involved in the strengthening method. Furthermore, three strengthening configurations were used to strengthen each of the three wire mesh variations and the two-strengthening method, i.e. (-), L and (Z) configuration. The unreinforced and reinforced triplet masonry wallets were tested under direct shear test. From the results obtained, the 'BJ'triplet masonry wallets observed an enhanced in shear strength of about 2.23% to 23.33 % whereas the 'BHJ' triplet masonry wallets observed an enhanced in shear strength of about 22.92% to 50.69%. The "BHJ" strengthening method effectively enhance the shear strength of the triplet masonry wallets compared to the "BJ" and the "UR" wallets with an increase in capacity as the wire mesh strength increases. Furthermore, in terms of the strengthening configuration, the (Z) configuration performs better, followed by the (L) and (-) configuration demonstrating the strengthening configuration effectiveness.

• 한국자동차공학회논문집
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• 제2권6호
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• pp.57-65
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• 1994

A collision-free path planning algorithm between an articulated robot and polyhedral obstacles using configuration space is presented. In configuration space, a robot is treated as a point and obstacles are treated as grown forbidden regions. Hence path planning problem is transformed into moving a point from start position to goal position without entering forbidden regions. For mapping to 3D joint space, slice projection method is used for first revolute joint and inverse kinematics is used for second and third revolute joint considering kinematic characteristics of industrial robot. Also, three projected 2D joint spaces are used in search of collision-free path. A proper example is provided to illustrate the proposed algorithm.

• Journal of Welding and Joining
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• 제14권2호
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• pp.71-78
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• 1996

In order to rpovide proper SMT design criteria in a systematic way, a mathematical formulation has been developed to predict the configuration of the solder fillet formed between the gullwing type lead and rectangular pad. Effects of SMT design parameters such as the solder volume and pad dimension on the solder profile are investigated using the FEM that calculates the 3D configuration by minimizing the energy due to surface tension and gravity in the equilibrium state. Design criteria of QFP and SOP are illustrated by plotting the acceptable range of the solder volume with respect to the length and width ratios of the pad and lead. The results show that the acceptable design range increases with increase in the pad length and width. The pad length has more significant effects on design criteria compared with the pad width, and Bond number can be utilized to predict the joint quality.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.834-839
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• 2004

In this paper, we investigate the optimal base position and joint configuration of a planar wheeled mobile manipulator in terms of manipulability measure. Taking into account the level of coordination between a manipulator and a platform, both local and global optimization problems are considered. First, based on the kinematic models of a mobile manipulator, the manipulability measures are expressed along with the analysis of the configurational dependency. Second, the geometric symmetry of a mobile manipulator in view of manipulability measure is analyzed, and for some base positions, the best and worst joint configurations are determined, Third, with reverence to the maximum, minimum, and average manipulability measures, the optimal base positions are determined, and the percent improvements due to the base relocation are discussed considering the relative scales among the platform size, the wheel radius, and the link length.

• 한국전산구조공학회논문집
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• 제20권1호
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• pp.51-56
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• 2007

해양구조물에서 많이 사용되는 K-Joint는 그 구조특성으로 인해 응력집중이 발생하며 최적 설계를 위한 가이드라인제시가 요구된다. 형상특성에 따른 응력집중 현상이 다르게 발생함으로 형상을 결정하는 각종 변수인 ${\alpha},\;{\beta},\;{\gamma},\;{\tau},\;{\theta}$의 변화에 따른 조인트의 응력변화를 분석하였다. 수치적인 패라메트릭 연구를 통해 응력 변화 특성을 제시하였고 주요 요소에 따른 최대 응력값도 나타내었고 수치해석 결과를 실험값과 비교하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.104.5-104
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• 2002

In this paper, we focus on a configuration control method of a redundant manipulator. The configuration of a redundant manipulator has been determined by geometry constraints and additional conditions, such as obstacle avoidance and dexterity optimization. This paper also utilizes optimization, and the additional condition (or performance index) to be optimized is stiffness of the end-effector and joints' torque. Stiffness and torque may be a natural attribute to be controlled during working and those vary as manipulator configuration does. So the optimal configuration from the viewpoint of stiffness and joint torque is studied. If the servo control mechanism of the joints Is assumed to be a...

• Imaging Science in Dentistry
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• 제31권2호
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• pp.93-99
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• 2001

Purpose: To analyze the possible association between magnetic resonance imaging signal intensity of temporomandibular joint disk and posterior attachment, and the type and extent of disk displacement, disk configuration, effusion and clinical signs in patients with internal derangement. Materials and Methods: Magnetic resonance images of the 132 temporomandibular joints of 66 patients with temporomandibular joint displacement were analyzed. The clinical findings were obtained by retrospective review of the patients' records. The type and extent of disk displacement, disk configuration and effusion were evaluated on the proton density MR images. The signal intensity from the anterior band, posterior band and posterior attachment were measured on MR images. The associations between the type and extent of disk displacement, disk configuration, effusion and clinical signs and the MR signal intensity of disk and posterior attachment were statistically analyzed by student's t-test. Results: Of 132 joints, 87 (65.9%) showed anterior disk displacement with reduction (ADR) and 45 (34.1%) showed anterior disk displacement without reduction (ADnR). The signals from posterior attachments were lower in joints with ADnR than those of ADR (p<0.05). The results showed statistically significant (p<0.05) association between the type and extent of disk displacement and disk configuration, and decreased signal intensity of posterior attachment. There were no statistical associations between pain, noise and limited mouth opening, and signal intensity of disk and posterior attachment. Conclusions: The average signal from posterior attachment was lower in joints with ADnR than that of ADR. The type and extent of disk displacement and disk configuration appeared to be correlated with the signal intensity from posterior attachment.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.48-53
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• 2004

In this paper, the task-oriented optimal configuration in the sense of Velocity and Force manipulability measure of manipulator mounted on ROV is considered. Manipulability is a quantitative measure of manipulator's capability obtained under the limits of joint velocities or torques. The base arrangements and optimal joint configuration of manipulator, that maximize the manipulability measure under the constraints of given task, are investigated. With the two types of base arrangements of manipulator, workspace analysis is carried out to investigate merits and demerits of each arrangement on the view of manipulability measure. To find optimal joint configuration for a given task with each arrangement, the SQP(Sequential Quadratic Programming) optimization are performed. Weighted linear combination of velocity and force manipulability measure is object function for SQP optimization. The kinematic parameters of Dual Orion manipulator which will be mounted on KORDI ROV are used for simulation.

• 대한족부족관절학회지
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• 제8권2호
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• pp.191-194
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• 2004

Purpose: Anatomic configuration of the ankle joint is useful information during various ankle procedures. This study was prospectively designed to investigate the sagittal inclination pattern of the ankle joint. Materials and Methods: Lateral standing ankle radiographs from one-hundred people (age: $17{\sim}68$, M:F=45:55) and magnetic resonance (MR) sagittal ankle images from twenty-four people (age: $16{\sim}65$, M:F=14:10) were studied. Post-traumatic, arthritic, or grossly deformed ankles at any reason were excluded. The posterior inclination angle (PIA) of the distal tibia was measured and compared between the lateral and the medial segment. Results: On plain radiographic data, the average PIA of the distal tibia was $6.14^{\circ}{\pm}3.56^{\circ}$ (range $0^{\circ}$ to $14^{\circ}$) in the lateral segment and $13.16^{\circ}{\pm}3.05^{\circ}$ (range $6^{\circ}$ to $22^{\circ}$) in the medial segment. On MR imaging data, the average PIA of the distal tibia was $5.08^{\circ}{\pm}4.26^{\circ}$ (range $1^{\circ}$ to $10^{\circ})$ in the lateral segment and $10.16^{\circ}{\pm}4.87^{\circ}$(range $5^{\circ}$ to $17^{\circ}$) in the medial segment. The PIA between two segments was significantly different. Conclusion: The sagittal configuration of the medial area ankle joint and the lateral area ankle joint has difference in the degree of posterior inclination and shape of curvature.