• Transactions of the Korean Society of Mechanical Engineers
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• v.10 no.1
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• pp.102-109
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• 1986

Based on the Hartenberg-Denavit symbolic equation, which is one of equations for the kinematic analysis of three dimensional (3-D) linkage, a generalized kinematic motion equation is derived utilizing Euler angles and employing the coordinates transformation. The derived equation can feasibly be used for the motion analysis of any type of 3-D linkages as well as 2-D ones. In order to simulate the general motion of 3-D linkgages on digital computer, the generalized equation is programmed through the process of numerical analysis after converting the equation to the type of Newton-Raphson formula and denoting it in matrix form. The feasibility of theoretically derived equation is experimentally proved by comparing the results from the computer with those from experimental setup of three differrent but generally empolyed 3-D linkages.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.3
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• pp.565-572
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• 1994

A method for the classification of kinematic chains according to the similarity in their structures is proposed. Classifcation code is defined from the contracted graph of the kinematic chain. This method of classifying kinematic chains can be effectively used for the systematic enumeration of structurally distinct kinematic chains given the number of links and degrees of freedom of the kinematic chains. Two separate steps for the enumeration are developed in the study. The first step is to generated all the possible classification codes and the next step is to generate individual kinematic chains belonging to each classification code generated. Using this two step procedure, kinematic chains up to 12 links are successfully enumerated in the present study. It is concluded that the two step method can be efficiently used for the type synthesis of mechanisms.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.10
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• pp.2543-2554
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• 1993

In this paper, the kinematic and dynamic analyses of spatial complex kinematic chain are studied. Through the new method both using the set of identification numbers and applying the DenavitHartenberg link representation method to the spatial complex kinematic chain, the kinematic configuration of the chain is represented. Some link in the part of closed chain being fictitiously cutted, the complex kinematic chain is transformed to the branched chain. The kinematic constraint equations are derived from the constraint conditions which the cutted sections of the link have to satisfy. And the joint variables being partitioned in the independent joint variables and the dependent joint variables, the dependent variables are calculated from the independent variables by using the Newton-Raphson iterative method and the pseudoinverse matrix. The equations of motion are derived under the independent joint variables by using the principle of virtual work. Algorithms for dynamic analysis are presented and simulations are done to verify accuracy and efficiency of the algorithms.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.11
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• pp.3398-3407
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• 1996

In this paper, we derive an algorithm and develope a computer program which analyze rapidly and precisely the inverse kinematics of robotic mechanism with spatial complex chain structure based on the relative coordinates. We represent the inverse kinematic problem as an optimization problem with the kinematic constraint equations. The inverse kinematic analysis algorithm, therefore, consists of two algorithms, the main, an optimization algorithm finding the motion of independent joints from that of an end-effector and the sub, a forward kinematic analysis algorithm computing the motion of dependent joints. We accomplish simulations for the investigation upon the accuracy and efficiency of the algorithm.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.12
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• pp.2889-2889
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• 2000

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.3
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• pp.11-17
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• 1998

In this study, a procedure is presented for the dynamic analysis of a multibody tracked vehicle system. the planner tracked vehicle model used in this investigation is assumed to consist of two kinematically decoupled subsystems, i.e., the chassis subsys- tem and track sub-system. The chassis subsystem includes the chassis frame, sprocket, idler and rollers, while the track subsystem is represented as a closed kinematic chain consisting of rigid links interconnected by revolute joints. The recursive kinematic and dynamic formulation module of the vehicle will be developed.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.2
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• pp.102-111
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• 2000

Methodology of volumetric error identification and compensation is presented to improve the accuracy of NC machine tools by using a reference artifact and a touch trigger probe. Homogeneous transformation matrix and kinematic chain are used for modeling the geo-metric and thermal errors of a three-axis vertical machining center. The reference artifact is designed and fabricated to identify the model parameters by machine tool metrology. Parameters in the error model are able to be identified and updated by direct measurement of the reference artifact on the machine tool under the actual conditions which include the thermal interactions of error sources. A volumetric error compensation system based on IBM/PC is linked with a FANUC CNC controller to compensate for the identified volumetric error in machining workspace.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.12
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• pp.2899-2908
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• 2000

Methodology of volumetric error identification is presented to improve the accuracy of NC machine tools by using a reference artifact and a touch trigger probe. Homogeneous transformation matrix and kinematic chain are used for modeling the geometric and thermal errors of a three-axis vertical machining center. The reference artifact is designed and fabricated to identify the model parameters by machine tool metrology. Parameters in the error model are able to be identified and updated by direct measurement of the reference artifact on the machine tool under the actual conditions which include the thermal interactions of error sources. The proposed method can speed up and simplify volumetric error identification processes.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1979.05a
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• pp.4.4-5
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• 1979

The degree of hearing impairment of chronic otitis media will indicate the nature and severity of middle ear pathology especially condition of ossicular chain, size of ear drum perforation and location of granulation tissue in the middle ear cavity. The subjects were 189 ears of tympanoplasty for chronic otitis media and divided into four groups as follows: Normal ossicular chain with only ear drum perforation (group I), normal ossicular chain with granulation tissue only around the ossicles regardless of any other region (group II), ossicular ankylosis or fixation of handle of malleus to promontory with or without granulation tissue around the ossicle (group III) and ossicular interruption by partial or complete destruction(groupf IV). The results were concluded as follows: 1) The average hearing threshold of chronic otitis media was 44.6 dB and hearing threshold was closely related to the condition of ossicular chain. Hearing threshold became greater in order of normal ossicular chain, ankylosis and interruption. 2) The average hearing threshold of ossicular interrupted group was 49.1 dB and it was greater in the cases of total destruction than that of partial destruction. 3) The hearing loss in the cases of normal ossicular chain with only tympanic membrane perforation was within 45 dB and this level was presumed to represent normal ossicular function. The degree of hearing loss was in proportion to the size of ear drum perforation and when over 45 dB, other middle ear pathology was suggested. 4) In the cases of small ear drum perforation with normal ossicular function, the hearing threshold was within 30 dB. 5) In the type of audiogram, flat type was 30.2% and ascending type 35.4%. Descending type was more frequent in the cases of normal ossicular mobility with granulation tissue around the ossicle and flat type was observed frequently in the cases of ossicular ankylosis. 6) Carhart's notch was seen in 14 cases (7.4%) and observed mainly in ossicular ankylosis. 7) There was no relation between hearing threshold and histopathological type of granulation tissue in chronic otitis media. However the degree of hearing impairment was related to the location of granulation tissue in the middle ear cavity. 8) Authors recognized the granulation tissue compensated the function of interrupted ossicular chain.

• 한국해양학회지
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• v.3 no.2
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• pp.63-72
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• 1968

해양에 있어서의 생물체의 에너지 순환, 즉 해양에 있어서의 생산체계에서 이중 먼저 기초생산체계만이라도 그 전상을 파악하자는 일은 먼 옛날부터 해양생물학자들의 진지하고도 끊임없는 추구대상이었다. 해양에는 막대한 양의 바닷물이 잠겨있고, 이곳에는 엄청난 양의 생명체가 함양되어 있으며, 이것들은 피포식자-포식자의 계열에서 어떠한 균형상태를 이루고 있는가하는 문제는 극히 흥미가 진진한 문제이다. 해양에 함양되는 무수한 생명체들은 간단없이 명멸, 소장만을 거듭하고 있다는 시적인 형용과 연상은 한층 더 구체화되어야 한다. 이러한 경향은 또한 근래의 세계인구의 격증에 대비하는 인간의 식량조달의 필요상, 해양이 지닌 잠재적인 식량생산의 여력을 재평가하자는 기운에서 한층 더 박차가 가해졌었다. 식량생산의 보고로서 해양에 주어진 책무는 크기만 하다. 해양에 잠겨있는 막대한 양의 바닷물은 긴 년월에 걸쳐 자연이 조제한 훌륭한 하나의 배양액이라고 불수 있고, 이것의 다각적인 이용개발은 지금부터 시작되었다고 해도 과언이 아니다. 근래에 이르러 각종기구 및 측기의 발달에 따라 해양의 물리, 화학 및 생물학적인 미세구조가 점차적으로 해명됨에 따라 해양학에 있어서의 고전적이고 전통적인 개념에 수정을 강요하는 사태가 적지않게 일어나고 있다. 해양의 기초생산체계에 대한 개념도 크게 비약하고 있으며, 해양에 있어서의 식물플랭크톤->동물플랭크톤->소형동물->어류를 연결하는 일방통행적인 식물연쇄개념을 크게 확대하고 비약시키지 아니하면 안될 여러 가지 사실이 들어나고 있다. 해양의 생물생산계의 기초적인 역할을 하는 것은 식물플랭크톤, 데트리타스 (detritus)등을 포함한 미소현탁물이라는 것은 틀림이 없으나, 이것들이 생명물질 기워니 아니드라도 물리현상으로 일어나는 기포를 매개로 하여 생성할수 있는 가능성이 제시되었다. 여기서는 이러한 해양의 미소현탁물에 관한 연구에 대해서 그 의의와 연구결과를 요약 소개하여 해양학도들의 참고로 한다. 이 종설을 꾸미는데 Jorgensen(1962), riley(1963), Parsons(1963), 서택(1966)등의 같은 토픽스에 관한 종설을 많이 참고로 한 것을 부기한다.