• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.388-393
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• 1990

A robot manipulator and an obstacle are described mathematically in joint space, with the mathematical representation for the collision between the robot manipulator and the obstacle. Using these descriptions, the robot motion planning problem is formulated which can be used to avoide a time varying obstacle. To solve the problem, the constraints on motion planning are discretized in joint space. An analytical method is proposed for planning the motion in joint space from a given starting point to the goal point. It is found that solving the inverse kinematics problem is not necessary to get the control input to the joint motion controller for collision avoidance.

• The korean journal of orthodontics
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• v.22 no.1
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• pp.109-121
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• 1992

Temporomandibular joint is a major structure to play an important role in the function & stability of the occlusion as well as the stomatognathic system. Therefore, the TMJ is the structure that requires the complete analysis for diagnosing and planning treatment of pathologic changes by TMJ dysfunction and malocclusion. So, in this study, to evaluate TMJ situation in Korean malocclusion, based on the previous accomplishments, students of the dental college of Won-Kwang Univ. are surveyed and selected in terms of Angle's classification of malocclusion, whose TMJ radiographs were taken in the centric occlusion and centric relation. In each maiocclusion groups, the mean and standard deviation of anterior, posterior and superior joint space of the right, left and both side in CO & CR are evaluated and also those of the fossa height and the articular eminence angle of the right, left and both sides are evaluated. The obtained results were as follows: 1. In the correlation coefficient between the malocclusion groups, no other items except the posterior joint space of the right side in CR between in class I and class III are significant. 2. In the correlation coefficient between the right and left side, the each joint space in class I malocclusion group and class II malocclusion group are significant. 3. In the change of each joint space during the transmit from CO to CR, there is a tendency of increasing anterior joint space and decreasing posterior, superior joint spaces in class I, II malocclusion and increasing superior joint space and decreasing anterior, posterior joint space in class III malocclusion, which is significant in the correlation coefficient, but not significant in the T-test. 4. In each malocclusion group, the correlation coefficient between the posterior joint space and the superior joint space in C.R is highly significant. 5. The fossa height of class II malocclusion group is lesser than that of class I or class III, which is not significant in T-test. 6. In the correlation coefficient between Rt. and Lt. side in the fossa height, it is not significant in class I and class III group, but significant in class II malocclusion group. 7. The articular eminence angle of class II malocclusion group is larger then that of class I or class III groups, which is fairly significant. 8. In the correlation coefficient between Rt. and Lt. side in the articular eminence angle, it is significant in each malocclusion group.

• Imaging Science in Dentistry
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• v.33 no.1
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• pp.1-4
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• 2003

Purpose : The purpose of this study was to investigate the distribution and frequency of temporomandibular joint (TMJ) effusion in magnetic resonance (MR) images of patients with disc displacements. Materials and Methods: On T2 weighted MR images of 148 TMJs taken from 74 patients presenting with TMJ pain and dysfunction, we assessed the cases showing TMJ effusion, defined as an amount of fluid that exceeded the maximum amount seen in a control group of asymptomatic volunteers. The amount of TMJ fluid was graded as: I (none or minimal), II (moderate), III (marked), and IV (extensive), according to a standard set by a reference. Disc displacement categories were also recorded. Results: Of the 148 TMJs examined in this study, 52 joints (35.1%) presented with joint effusion, 24 (16.2%) showing bilateral joint effusion. 38 joints showed upper joint space effusion, 3 showed lower joint space effusion, and 11 showed both upper and lower joint space effusion. 96 joints (64.9%) had grade I joint fluid, 27 (18.2%) grade II, 15 (10.1 %) grade III, and 10 (6.8%) grade IV. 80.0% of the joints presenting with grade IV effusion showed disc displacement without reduction. Conclusion: Joint effusion was found not only in upper, but also in lower joint spaces. The higher the effusion grade, the greater the frequency of disc displacement without reduction.

• Korean Journal of Mathematics
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• v.13 no.1
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• pp.43-50
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• 2005

We introduce the Joint spectrum on the complex Banach space and on the complex Hilbert space and the tensor product spectrums on the tensor product spaces. And we will show ${\sigma}[P(T_1,T_2,{\ldots},T_n)]={\sigma}(T_1{\otimes}T_2{\otimes}{\cdots}{\otimes}T_n)$ on $X_1{\overline{\otimes}}X_2{\overline{\otimes}}{\cdots}{\overline{\otimes}}X_n$ for a polynomial P.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1820-1823
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• 1997

For the Cartesian space position controlled robot, it is required to have the accurate mapping from the Cartesian space to the joint space in order to command the desired joint trajectories correctly. since the actual mapping from Cartesian space to joint space is obtained at the joint coordinate not at the actuator coordinate, uncertainty in Jacobian can be present. In this paper, two feasible neural network schemes are proposed to compensate for the kinematic Jacobian uncertainties. Uncertainties in Jacobian can be compensated by identifying either actuator Jacobian off-line or the inverse of that in on-line fashion. the case study of the stenciling robot is examined.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.6
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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 Korean Academy of Oral and Maxillofacial Radiology
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• v.19 no.1
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• pp.105-121
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• 1989

The author analysed tomograms and submento-vertex radiograms of 90 temporomandibular joints from 45 asymptomatic young adults. 15 had Angle class Ⅰ malocclusion, 15 classⅡ and 15 class Ⅲ. Corrected lateral tomograms were obtained in three condylar positions; centric occlusion, centric relation and 1 inch mouth opening. The condylar angulation, depth of cut, joint spaces were analysed in each radiogram. The obtained results were as follows; 1. The mean condylar angulation in Angle class Ⅰ, Ⅱ, Ⅲ group was 17.55±5.51° 13.33±8.85° 16.25±6.60° respectively, and there was no significant difference in each group. The mean condylar angulation of right side (16.62±7.23°) was larger than left side (14.80±7.33°). 2. The mean depth of cut in Angle class Ⅰ, Ⅱ, Ⅲ group was 8.13±1.61㎝, 3.05±3.80㎝, 7.75±2.19㎝, respectively. Angle class Ⅰ and class Ⅱ group revealed significant difference in measurement (p<0.0l). 3. The mean height of articular fossa in Angle class Ⅰ, Ⅱ, Ⅲ group was 8.67±3.06㎜, 9.61±2.57㎜, 8.93±2.83㎜, respectively. And the mean width of articular fossa was 19.90±2.80㎜, 19.48±3.83㎜, 20.36±4.82㎜, respectively. 4. The mean height and width of condylar head was 5.11±1.16㎜, 11.20±2.26㎜, respectively. 5. In centric occlusion, the superior joint space was the largest (3.42±1.42㎜), followed by anterior joint space (2.94±1.95㎜) and the posterior joint space (2.64±1.19㎜. In centric relation, the anterior joint space was the largest (3.86±2.17㎜), followed by the superior joint space (3.64±3.68㎜) and the posterior joint space (1.18±0.77㎜). 6. The displaced measurement from centric relation to centric occlusion was 1.10±1.04㎜ anteriorly and 0.24±0.97㎜ inferiorly. In 1 inch mouth opening state, the condylar head displaced posteroinferiorly (2.49±2.49㎜ posteriorly, 1.17±1.34㎜ inferiorly) from the apex of articular eminence. And Angle class Ⅰ and Ⅱ group, Angle class Ⅱ and Ⅲ group revealed significant difference in posterior measurement, respectively (p<0.01).

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.763-766
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• 1991

The moving of each axis in the robot manipulator can be represented with the motion of cartesian space. This paper shows the robot manipulator of the straight line trajectory planning algorithms in the cartesian space. The relation formulas between cartesian space and joint space are induced to accomplish a desired trajectory in the cartesian space and the velocity vector of sampling time in the cartesian space is transformed into the velocity vector of joint by the interpolation method. The error of trajectory in moving is removed by obtaining the real position for the present joint position and the desired distance is made by comparing the real position and the next position. Through the simple tests for suggested algorithms are confirmed the validity of algorithms.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.854-861
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• 2005

Studied accuracy and practical use possibility of joint measurement that using 3D laser scanner to rock slope. Measured joint of Rock slope and comparison applied 3 dimension laser scanner and clinometer. 3D laser scanning system preserves on computer calculating to 3 dimension coordinate scaning laser to object. and according to laser measurement method of interior, produce correct vector value from charge-coupled device(CCD) or laser reciver and telegram register and time measuring equipment. Create of object x, y, z point coordinates to 3 dimension space of computer. Such 3 dimension point datum (Point Clouds) forms relocate position informations that exist to practical space to computer space. Practical numerical values related between each other. Compared joint distribution and direction that measured by laser scanner and clinometer. By the result, Distribution of joint projected almost equally. Could get more joint datas by measurement of 3 dimension scanner than measured by clinometer. Therefore, There is effect that objectification of rock slope investigation data, shortening of investigation periods, investigation reduction of cost. could know that it is very effective method in joint measuring.

• The Journal of the Korean dental association
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• v.41 no.12 s.415
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• pp.818-824
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• 2003

Visually guided irrigation and lysis(VGIL) using temporomandibular joint(TMJ) arthroscope is useful for decreasing pain and increasing the functional mobility of TMJ. Also it demonstrated similar effectiveness comparing with arthrocentesis. Arthroscopy permits intracapsular inspection that is imperative not only for identification of morphological characteristics of joint space, but also for adequate irrigation and lysis of specific joint space. Conventional 2.3mm diameter arthroscope with 2.7mm catheter was too wide. So it was traumatic and uncomfortable to manipulate on temporomandibular joint space, especially on TMJ internal derangement patient with reduced space. We report our clinical experience on 6 TMJ closed lock patients who were treated with new 1.2mm fiberscope at Chung Hoon Dental Clinic between March 2003 and August 2003. Also we present clinical advantage & disadvantage of new system with literature review.