• Title/Summary/Keyword: joint compliance

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Compliance Paradigms for Kinematically Tedundant Manipulators

  • Park, Jonghoon;Chung, W.K.;Youm, Y.
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10a
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    • pp.914-919
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    • 1993
  • The kinematic resolutions of redundancy is addressed in this paper. The governing equation for quasistatic behavior of compliance governed redundant manipulators is formulated and the repeatable property of the manipulator is proposed. Then the compliance paradigm is used to resolve the redundancy in a repeatable way. The compliance paradigm is one under which the controller simulates the imaginary manipulator which is governed to move by real joint stiffness. The equation is expressed as the weighted pseudoinverse with the configuration dependent weighting matrix. Algorithmic singularities arisen from this scheme are also discussed.

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A Study on the Optimum Design of Compliance Characteristics of Suspension System (현가계 컴플라이언스 특성의 최적 설계에 관한 연구)

  • Lee, J.M.;Kang, J.S.;Tak, T.O.;Yoom, J.W.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.6
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    • pp.88-97
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    • 1998
  • Compliance elements such as bushings of a suspension system play a crucial role in determining the ride and handling characteristics of the vehicle. In this paper, a general procedure is proposed for the optimum design of compliance elements to meet various design targets. Based on the assumption that the displacements of elastokinematic behavior of a suspension system under external forces are very small, linearized elastokinematic equations in terms of infinitesimal displacements and joint reaction forces are derived. Directly differentiating the linear elastokinematic equations with respect to design variables associated with bushing stiffness, sensitivity equations are obtained. The design process for determining the bushing stiffness using sensitivity analysis and optimization technique is demonstrated.

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A Research on RC3(RMF-CMMC Common Compliance) meta-model development in preparation for Defense Cybersecurity (국방 사이버보안을 위한 RMF-CMMC 공통규정준수 메타모델 개발방안 연구)

  • Jae-yoon Hwang;Hyuk-jin Kwon
    • Journal of Internet Computing and Services
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    • v.25 no.1
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    • pp.123-136
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    • 2024
  • The U.S. Department of Defense, leading global cybersecurity policies, has two main cybersecurity frameworks: the Cybersecurity Maturity Model Certification (CMMC) for external defense industry certification, and the Risk Management Framework (RMF) for internal organizational security assessments. For Republic of Korea military, starting from 2026, the Korean version of RMF (K-RMF) will be fully implemented. Domestic defense industry companies participating in projects commissioned by the U.S. Department of Defense must obtain CMMC certification by October 2025. In this paper, a new standard compliance meta-model (R3C) development methodology that can simultaneously support CMMC and RMF security audit readiness tasks is introduced, along with the implementation results of a compliance solution based on the R3C meta-model. This research is based on practical experience with the U.S. Department of Defense's cybersecurity regulations gained during the joint project by the South Korean and U.S. defense ministries' joint chiefs of staff since 2022. The developed compliance solution functions are being utilized in joint South Korean-U.S. military exercises. The compliance solution developed through this research is expected to be available for sale in the private sector and is anticipated to be highly valuable for domestic defense industry companies that need immediate CMMC certification.

A variably compliable probe system for the in-circuit test of a PCB (인쇄회로기판의 통전검사를 위한 가변순응력을 갖는 프로브 시스템)

  • Shim, Jae-Hong;Cho, Hyung-Suck;Kim, Sung-Kwun
    • Journal of Institute of Control, Robotics and Systems
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    • v.3 no.3
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    • pp.323-331
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    • 1997
  • A new probing mechanism and an active compliance control algorithm have been developed for the in-circuit test of a PCB( printed circuit board ). Commercially available robotic probing devices are incapable of controlling contact force generated through rigid probe contacts with a solder joint, at high speed. The uncontrollable excessive contact force often brungs about some defects on the surface of the solder joint, which is plastically deformable over some limited contact force. This force also makes unstable contact motions resulting in unreliable test data. To overcome these problems, we propose that a serially connected macro and micro device with active compliance provide the best potential for a safe and reliable in-circuit test. This paper describes the design characteristics, modeling and control scheme of the newly proposed device. The experimental results clearly show the effectiveness of the proposed system.

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Reliability based calibration of the capacity design rule of reinforced concrete beam-column joints

  • Thomos, George C.;Trezos, Constantin G.
    • Computers and Concrete
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    • v.8 no.6
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    • pp.631-645
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    • 2011
  • The capacity design rule for beam-column joints, as adopted by the EC8, forces the formation of the plastic hinges to be developed in beams rather than in columns. This is achieved by deriving the design moments of the columns of a joint from equilibrium conditions, assuming that plastic hinges with their possible overstrengths have been developed in the adjacent beams of the joint. In this equilibrium the parameters (dimensions, material properties, axial forces etc) are, in general, random variables. Hence, the capacity design is associated with a probability of non-compliance (probability of failure). In the present study the probability of non-compliance of the capacity design rule of joints is being calculated by assuming the basic variables as random variables. Parameters affecting this probability are examined and a modification of the capacity design rule for beam-column joints is proposed, in order to achieve uniformity of the safety level.

Analysis on characteristics of antagonistic stiffness of the planar 3 degrees-of-freedom RCC mechanism (평면형 3 자유도 RCC 메카니즘의 상반효과로 인한 강성 특성 분석)

  • 이병주;김희국;이준용
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.718-721
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    • 1996
  • In this work, an effective stiffness generated by internal loading for a planar 3 degrees of freedom RCC mechanism is investigated. For this purpose, the internal kinematic analysis and antagonistic stiffness modeling for this mechanism are performed. It is shown that the antagonistic stiffness could be effectively created at the center of the mechanism in its symmetric configuration.

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Design of Compliant Hinge Joints inspired by Ligamentous Structure (인대 구조에 기인한 유연 경첩 관절의 설계)

  • Lee, Geon;Yoon, Dukchan;Choi, Youngjin
    • The Journal of Korea Robotics Society
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    • v.14 no.4
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    • pp.237-244
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    • 2019
  • This paper suggests novel types of joint mechanisms composed of elastic strings and rigid bodies. All of the human hinge joints have the articular capsule and a pair of collateral ligaments. These fibrous tissues make the joint compliant and stable. The proposed mechanism closely imitates the human hinge joint structure by using the concept of tensegrity. The resultant mechanism has several characteristics shown commonly from both the tensegrity structure and the human joint such as compliance, stability, lightweight, and non-contact between rigid bodies. In addition, the role and feature of the human hinge joints vary according to the origins of a pair of collateral ligaments. Likewise, the locations of two strings corresponding to a pair of collateral ligaments produce different function and motion of the proposed mechanism. It would be one of the advantages obtained from the proposed mechanism. How to make a joint mechanism with different features is also suggested in this paper.

Comparative Study of Compliance for Venous Thromboembolism Prophylaxis (American College of Chest Physicians Guideline and American College of Orthopedic Surgeons Guideline) in High Risk Patients with a Venous Thromboembolism (정맥혈전 색전증 고위험군에서 시행한 혈전색전 예방요법(American College of Chest Physicians 지침 및 American College of Orthopedic Surgeons 지침)의 준수율 비교 연구)

  • Suh, You-Sung;Nho, Jae-Hwi;Jang, Byung-Woong;Kang, Deokwon;Won, Sung-Hun
    • Journal of the Korean Orthopaedic Association
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    • v.54 no.4
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    • pp.317-326
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    • 2019
  • Purpose: To compare and analyze the rate of prevention of two venous thromboembolism prophylaxis guidelines in patients with artificial joint arthroplasty and hip joint fracture. Proper prophylaxis for preventing thromboembolism in orthopedic surgery is significant because of this fetal complication. Materials and Methods: This study compared and retrospective analyzed the rate of prevention using the medical records and radiographs of patients who underwent orthopedic surgery from March 2009 to February 2011 according to the American College of Chest Physicians (ACCP) guidelines and from March 2012 to February 2014 according to the American Academy of Orthopedic Surgeons (AAOS) guidelines. Results: The guidelines for venous thromboembolism prophylaxis have been applied to patients with artificial joint replacement and hip joint fracture, the compliance rate of the ACCP guidelines was 56.0% before surgery, 67.0% after surgery with chemical prophylaxis, and 80.5% with mechanical prophylaxis. In addition, the compliance rate of the AAOS guidelines was 74.1% with chemical prophylaxis, and 88.3% with mechanical prophylaxis, which was higher than the ACCP guidelines. The compliance rates of mechanical and chemical prophylaxis before and after surgery of the ACCP guidelines, and the compliance rate of mechanical and chemical prophylaxis of the AAOS guidelines were compared and analyzed. The results revealed statistical significance (p<0.05) before and after total knee replacement arthroplasty and hip joint fracture internal fixation and total high risk orthopedic surgery. Conclusion: Raising the compliance rate of prophylaxis of venous thromboembolism in high risk orthopedic surgery is necessary and people should follow the guidelines for a unified direction depending on which situation they are in.

A study on knowledge, self-efficacy and compliance in Reumatic arthritis Patients (류마티스 관절염 환자의 지식, 자기효능감 및 치료이행과의 관계연구)

  • Kim, Soon-Bong
    • Journal of muscle and joint health
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    • v.5 no.2
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    • pp.238-252
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    • 1998
  • Reumatic arthritis is a disease with joint pain being one of the key symptoms. The patient suffers from the pain, stiff sensation and edema due to the inflammation taking Place In one or more joints. Accompanying these problems are fatigue, unusual exhaustion, fever, tachycardia and weakness. Inaddition, joints are often deformed and muscles shrink along with the progress of edema, coupled with depression and psychological instability resulting from the loss of the mobile function and limitations on the daily life. Some patients become fed up with the long and hard flight with the disease and just give up, which aggravates the symptoms. Others come to the hospital only when the conditions have become serious. We need to prevent these and guide the patients in the right direction. Against this backdrop, this study aims to look into the relations between the knowledge on the part of the patients together with their feeling of self-efficacy and the compliance. The results are expected to help the patients improve their life, In addition to providing useful materials for setting up appropriate plan for nursing intervention. The study was conducted by distributing questionnaire to 88 patients selected from the out-patient department of a university hospital in Inchon, from April 6 to 27, 1998. The following tools were used the yardstick of self-efficacy, developed in 1997 by the Society for the Health of Rheumatism Patients, was used for measuring the levels of knowledge and the feeling of self-efficacy. The degree of compliance was measured by the data collected from documents in addition to the results of the analysis of the interviews with the patients. The reliability of the tools was confirmed. In the analysis, the general characteristics were expressed in figures and percentages. The levels of knowledge, feeling of self-efficacy, and compliance were expressed in the average values and standard deviations. The relations among the variables following the general characteristics were analysed by the t-test and one-way ANOVA. The Pearson correction coefficient was used for the analysis of factors. Multiple-loop analysis was used to identify the variables affecting the compliance. The following are the results of this study. 1. Among the 88 patients, 18 were men and the remaining 70 were women, with a ratio 1 : 3.87. Regarding the age groups, 23 were between 50 and 59 years old, with those between 50 and 69 accounting for 51.1% of the total. High school graduates or higher amounted to 58%. Religious patients was 67% or 59 persons. Fifty nine percent were unemployed, and 58.3% (49 persons) had two children or fewer. The period of suffering from rheumatism varied between 2 months and IS years, with 70% less than years. 2. The average figure In relation to the of knowledge was 17.63 points over 30 or 58. 76%, which means a medium level. 3. The average figure of the feeling of self-efficacy was 60.06 points. 4. The level of compliance was 3.26, which was above average. 5. The relation between the feeling of self-efficacy and compliance showed an "r" value of 0.37, which was significant. It means that the higher the feeling, the greater the compliance points. 6. The analysis of the knowledge level revealed that the difference is found only between the college graduates and junior-high graduates or lower. 7. The feeling of self-efficacy varied along with the age and education level. 8. The general characteristics of patients as discussed above did not show significant difference with the compliance. 9. Regarding the elements influencing the compliance, the number of children, period of suffering, income, age, feering of self-efficacy, knowledge, and compliance had 54% of significance. In conclusion, rheumatism victims can lead a better life if they are appropriately educated, based on efficient training program from the early days of the disease ; if they become able to manage themselves thanks to the training ; and if they are helped by a program focusing on the increase of the feeling of self-efficacy aimed at changing patient's behavior.

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Stiffness Analysis of a Low-DOF Parallel Manipulator including the Elastic Deformations of Both Joints and Links (ICCAS 2005)

  • Kim, Han-Sung;Shin, Chang-Rok;Kyung, Jin-Ho;Ha, Young-Ho;Yu, Han-Sik;Shim, Poong-Soo
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.631-637
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    • 2005
  • This paper presents a stiffness analysis method for a low-DOF parallel manipulator, which takes into account of elastic deformations of joints and links. A low-DOF parallel manipulator is defined as a spatial parallel manipulator which has less than six degrees of freedom. Differently from the case of a 6-DOF parallel manipulator, the serial chains in a low-DOF parallel manipulator are subject to constraint forces as well as actuation forces. The reaction forces due to actuations and constraints in each limb can be determined by making use of the theory of reciprocal screws. It is shown that the stiffness model of an F-DOF parallel manipulator consists of F springs related to the reciprocal screws of actuations and 6-F springs related to the reciprocal screws of constraints, which connect the moving platform to the fixed base in parallel. The $6{times}6$ stiffness matrix is derived, which is the sum of the stiffness matrices of actuations and constraints. The six spring constants can be precisely determined by modeling the compliance of joints and links in a serial chain as follows; the link can be considered as an Euler beam and the stiffness matrix of rotational or prismatic joint can be modeled as a $6{times}6$ diagonal matrix, where one diagonal element about the rotation axis or along the sliding direction is zero. By summing the elastic deformations in joints and links, the compliance matrix of a serial chain is obtained. Finally, applying the reciprocal screws to the compliance matrix of a serial chain, the compliance values of springs can be determined. As an example of explaining the procedure, the stiffness of the Tricept parallel manipulator has been analyzed.

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