• Title/Summary/Keyword: Joint variable

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Cyclic loading test of abnormal joints in SRC frame-bent main building structure

  • Wang, Bo;Cao, Guorong;Yang, Ke;Dai, Huijuan;Qin, Chaogang
    • Earthquakes and Structures
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    • v.20 no.4
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    • pp.417-430
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    • 2021
  • Due to functional requirements, SRC column-RC beam abnormal joints with characteristics of strong beam weak column, variable column section, unequal beam height and staggered height exist in the Steel reinforced concrete (SRC) frame-bent main building structure of thermal power plant (TPP). This paper presents the experimental results of these abnormal joints through cyclic loading tests on five specimens with scaling factor of 1/5. The staggered height and whether adding H-shaped steel in beam or not were changing parameters of specimens. The failure patterns, bearing capacity, energy dissipation and ductile performance were analyzed. In addition, the stress mechanism of the abnormal joint was discussed based on the diagonal strut model. The research results showed that the abnormal exterior joints occurred shear failure and column end hinge flexural failure; reducing beam height through adding H-shaped steel in the beam of abnormal exterior joint could improve the crack resistance and ductility; the abnormal interior joints with different staggered heights occurred column ends flexural failure; the joint with larger staggered height had the higher bearing capacity and stiffness, but lower ductility. The concrete compression strut mechanism is still applicable to the abnormal joints in TPP, but it is affected by the abnormal characteristics.

Implementation of a Robust Dynamic Control System for SCARA Robot Using DSPs (DSP를 이용한 SCARA 로봇의 강인한 동적 제어시스템 실현)

  • 이장명;박흥인
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.2
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    • pp.58-69
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    • 1998
  • A contrp; suste, fpr SCARA robot is designed for implememting a robust dynamic control algorithm. this study forcuses on the use of DSPs in the design of joint controllers and interfaces in between the host cotroller and four joint controllers and in between the joint controllers and four servo drives. The mechanical body of SCARA robot and the servo drives are selected from the commercially available ones. The four joint controllers, assigned to each joint one by one, are combined into a common system through a mother board hardwarewise and through the global memeory softwarewise. The mother board is designed to connect joint controllers onto the board through the slots adopting PC/104 bus structures. And, the global memory stores the common data which can be shared by joint controllers and the host computer directly, which virtually combines the whole system into one. To demonstrate the performance and efficienty of the sytem, a robust inverse dynamic algorithm is proposed and implemented for a faster and more precise control. The robust inverse dynamic algorithm is basically derived from an inverse dynamci algorithm and a PID compensator. Based upon the derived dynamic equitions of SCARA robot, the inverse dynamic algorithm is intitially implemented within 0.3 msec of the control cycle in this system. The algoithm is found to be not accurate enough for the high speed and precision tasks due to inherent modelling errors and time-varying factors. Therefore, a variable PID algorithm is combined with the inverse dynamic algorithm to support robustness of control performance. Experimental datfor the proposed algorithm are presented and compared with the result obtained from PID and inverse dynamic algorithm.

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The Level of Pain, Gait Speed, and ROM in Community-dwelling Older Adults with Knee Joint Pain (슬관절통이 있는 재가노인의 통증과 보행속도 및 관절가동범위)

  • Kim, Kye-Ha;Lee, Jin-Min
    • Research in Community and Public Health Nursing
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    • v.28 no.2
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    • pp.156-164
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    • 2017
  • Purpose: The purpose of this study is to investigate the level of pain, gait speed, and ROM (Range of motion) in community-dwelling older adults with knee joint pain. Methods: A convenience sample of 160 participants living in G city were recruited. Elderly people who suffer from knee joint pain with a pain level ${\geq}5$ during the last one year on a visual analogue scale were included in the study. The data were collected from June to August 2016. All statistical analyses were performed using IBM SPSS ver. 22.0. Results: Participants' pain was 6.81 by VAS. The mean gait speed was 13.9 sec/10m. The ROM of left knee and right knee were $54.06^{\circ}$ and $56.50^{\circ}$, respectively. The level of pain was different according to gender (t=-4.87, p<.001), economic status (t=3.51, p=.032), diseases (t=5.23, p<.001), diagnosis of arthritis (t=3.86, p<.001), region of knee joint pain (F=9.30, p<.001), duration of pain occurrence (F=13.82, p<.001), and limp (F=3.58, p<.001). The level of knee joint pain and gait speed had significant correlations. Conclusion: The gait speed in older adults is an important variable that should be taken into account in the assessment of their level of knee joint pain.

A Study on the Development and Measurement of Logistics Partners Cooperation Index(LPCI): Focused on the Joint Logistics (물류협력지수의 개발 및 측정에 관한 연구: 공동물류사업을 중심으로)

  • Suh, Sang-Sok;Song, Gwang-Suk;Park, Jong-Woo
    • Journal of Distribution Science
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    • v.14 no.6
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    • pp.107-118
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    • 2016
  • Purpose - Over 90% of Domestic logistics industry is small enterprise and they are experiencing growth stagnation due to price-based competition structure rather than constructing logistics service of high added value. In order to get over this situation and pursue the development of logistics industry, strengthening its competitiveness, through inter-enterprise cooperative network build-up, would be a key alternative. Therefore, in this study, an index for measuring inter-enterprise cooperation level of Joint logistics business will be developed as a typical collaborative business model in logistics industry. Moreover, a strengthening competitiveness method suggests a developmental step and a key management index to mature in logistics industry. Research Design, Data, Methodology - This study is an index development research for measuring inter-enterprise cooperation level of logistics industry. Such a level was measured by performing a survey by targeting enterprises that participated in Joint logistics business. The targeting enterprises are typical cooperative models in logistics industry. Measurement items were developed which were based on the presented items in existing research. Question items were composed of selection type questions as answering Yes/No. They measures implementation status of corporate activity and detailed activity items measuring qualitative level. Total samples were based on 116 enterprise samples including 90 logistics enterprises and 26 shippers. In addition, by evaluating the importance for Joint logistics business recognition with personnel working level, the weight of measuring variable was extracted. This study has built an assessment tools (LPCI) on Joint logistics business cooperation level in a situation where there are no previous studies on joint logistics business, this study is meaningful for other studies. Results - As a result of analyzing LPCI presented in this study, the score of logistics enterprise was represented as 59.9 points based on full score of 100 points and that of shippers as 47.2 points and cooperation level among enterprises participated in Joint logistics business was revealed to be very low. In particular, as a result of measuring the importance between logistics enterprise and shippers, the difference by each measurement standard was represented among those enterprises. This difference is considered to be a key factor that cooperative operational conformity between logistics enterprises and shippers is represented to be low. Conclusions - As most joint logistics business, being promoted at present, is sharing facility and information with joint logistics business, it is hard to find such a joint logistics business in reality based on cooperative business model in main cooperation agents. Therefore, competitiveness of logistics industry could be strengthened by promoting joint logistics business based on their mutual cooperation among enterprises. In other words, it is to secure sustainable competitiveness of joint logistics business together with creation of new market by inter-enterprise cooperation based on integration of basic logistics business.

Stress-strain model of weak PVC-FRP confined concrete column and strong RC ring beam joint under eccentric compression

  • Yu, Feng;Zhang, Nannan;Fang, Yuan;Liu, Jie;Xiang, Guosheng
    • Steel and Composite Structures
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    • v.35 no.1
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    • pp.13-27
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    • 2020
  • To investigate the stress-strain relation of PVC-FRP Confined Concrete (PFCC) column with RC ring beam joint subjected to eccentric compression, the experiment of 13 joint specimens, which were designed with principle of "strong joint and weak column", were presented. Several variable parameters, such as reinforcement ratio, width and height of ring beam, FRP strips spacing and eccentricity, were considered. The specimens were eventually damaged by the crushing of concrete, the fracture of PVC tube and several FRP strips. With the FRP strips spacing or eccentricity increased, the ultimate carrying capacity of specimens declined. The strain of FRP strips and axial strain of PVC tube decreased as FRP strips spacing decreased. The decrease of eccentricity would slow down the development of strain of FRP strips and axial strain of PVC tube. The slope of stress-strain curve of PFCC column decreased as FRP strips spacing or eccentricity increased. The ultimate strain of PFCC column reduced as FRP strips spacing increased, while the effect of eccentricity on the ultimate strain of PFCC was not distinct. Considering the influence of eccentricity on the stress-strain relation, a modified stress-strain model for conveniently predicting the weak PFCC column and strong RC ring beam joint under eccentric compression was proposed and it was in good agreement with the experimental data.

Structural Behavior of Bolted Lap-Joint Connection in the Pultruded FRP Structural Members (볼트로 겹침이음된 펄트루젼 복합재 접합부의 구조적 거동)

  • Lee, Young-Geun;Shin, Kwang-Yeoul;Joo, Hyung-Joong;Nam, Jeong-Hun;Yoon, Soon-Jong
    • Composites Research
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    • v.23 no.1
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    • pp.37-43
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    • 2010
  • In this paper, we present the result of an experimental investigation pertaining to the structural behavior of bolted lap-joint connection of pultruded fiber reinforced plastic structural shapes. In the experimental investigation, in order to find the mechanical property of the material, tension and shear tests on the pultruded structural composite specimen are conducted prior to the investigation on the structural behavior of bolted lap-joint connection of the member. Based on the result, number of bolts, type of placement and location of bolt are determined to be a test variable. Three different types of experimental specimens are prepared. Tensile load is applied through the center of the specimen with lap-joint connection and the structural behavior and failure mode of the test specimens with respect to the tensile load increment are investigated. As a result, it is found that most of the failure mode at the lap-joint connection is shear failure mode. Consequently, it is also found that the data obtained through this experimental program could be used for the structure connection design as a basis.

Survey on Fibromyalgia Syndrome (섬유조직염 환자에 대한 기초 조사연구)

  • Han, Sang-Sook;Kang, Hyun-Sook
    • Journal of muscle and joint health
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    • v.4 no.1
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    • pp.74-86
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    • 1997
  • This investigation has been conducted based on the medical chart of 344 patients who have been diagnosed of fibromyalgia syndrome during Oct. 9, 1996 through Nov. 20 at the Rheumatism Hospital of H. University located in Seoul. 280 which have been included in the analysis. 1. Only one patient was male in 280 patients, age distribution was from 28 to 76, in which the average age was 52.4. 2. Percentage of treatment duration was 6 months in 46.1%, 3 years in 22.1% and 2 years in 12.5%. Considering these results, it can be predicted that the number of patients might be increased and accumulated in the future. 3. Percentage of patients having primary fibromyalgia syndrome was 39.3%, having combination with osteoarthritis was 36.7% and the rest case have combination with rheumatoid arthritis at the same time. 4. The percentage of cases having patients 10-12 tender points was 37.1%, while the most of cases have pain at 12-19 tender points. The common locations of the tender point were at lateral epicondyle of elbow in 92.0%, at midpoint of upper border Trapezius in 84.8%, at upper part of scapula Supraspinatus in 82.9%, at medial fat pad proximal to the joint line knee in 81.85%, at intertransverse of $C_{5-7}$ Low cervical in 73.4% and at 2nd distal costochondral Junction 2nd rib in 72.0%. And most of the patients had joint functional disability at all in 47.1% with average 2.41 joint functional disability. 5. Age was not a variable influencing the number of tender points and the number of joint functional disability.

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Physical Examination of the Elbow (주관절의 이학적 검사)

  • 김풍택;경희수;전인호
    • The Academic Congress of Korean Shoulder and Elbow Society
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    • 2003.11a
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    • pp.51-56
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    • 2003
  • The trained examiner can gain considerable information from visual inspections of the elbow joint, Because much of the joint is subcutaneous, any appreciable alteration in the skeletal anatomy often is detectable. Gross soft tissue swelling or muscle atrophy is also early observed. Inspection and palpation of the medial and lateral epicondyles and the tip of the otecranon from an equilateral triangle with the elbow is flexed. Normally, the arc of flexion extension, although variable, ranges from about O to 140 degrees plus or minus 10 degrees. The posterolateral rotatory instability(PLRI) of the elbow is most common pattern of elbow instability. The lateral collateral ligament complex also includes a narrow but stout band of ligamentous tissue blending with the distal and proterior fibers of the capsule to insert distally on the crista supinatoris of the ulna. This is the lateral ulnar collateral ligament(LUCL). A clinical elbow pivot shift test confirms the PLRI. There are also two active apprehension signs.

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An efficient joint disparity and motion estimation for stereoscopic video coding (변이-움직임 동시 추정을 이용한 스테레오 동영상 부호화 기법)

  • 유정열;임정은;손광훈
    • Proceedings of the IEEK Conference
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    • 2001.09a
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    • pp.345-348
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    • 2001
  • 본 논문에서는 변이-움직임 벡터의 상관관계를 통한 동시 추정(joint disparity and motion estimation)을 이용하여 방대한 계산량과 데이터량을 요구하는 스테레오 영상 데이터의 효율적인 부호화를 위한 알고리즘을 제안한다. 스테레오 시퀀스에 대해서 두 변이 벡터(disparity vector)와 하나의 움직임 벡터(motion vector)의 상관관계를 이용하면 나머지 움직임 벡터는 직접적인 추정 과정 없이 얻을 수 있다. 하지만, 이렇게 얻어진 움직임 벡터는 직접 추정에 비해 정확도가 현저히 떨어져 이 벡터를 그대로 사용하여 영상을 복원하게 될 경우 심각한 오차의 누적이 발생한다. 따라서 본 논문에서는 효율적인 동시 추정을 위해 추정단에서 벡터 평활화(vector regularization)과정을 수행하고 불확실 벡터 영역 추출을 통한 선택적인 보정 과정을 수행한다. 또한, 불확실 벡터 영역의 벡터만을 가변장 부호화(variable length coding)한다. 실험결과, 직접 추정 과정을 거치지 않고 도 만족할 만한 화질의 영상을 얻을 수 있었으며, 부호화량도 상당히 감소시킬 수 있었다.

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Relative Error Compensation of Robot Using Neural Network (신경 회로망을 이용한 로봇의 상대 오차 보상)

  • Kim, Yeon-Hoon;Jeong, Jae-Won;Kim, Soo-Hyun;Kwak, Yoon-Keun
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.7
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    • pp.66-72
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    • 1999
  • Robot calibration is very important to improve the accuracy of robot manipulators. However, the calibration procedure is very time consuming and laborious work for users. In this paper, we propose a method of relative error compensation to make the calibration procedure easier. The method is completed by a Pi-Sigma network architecture which has sufficient capability to approximate the relative relationship between the accuracy compensations and robot configurations while maintaining an efficient network learning ability. By experiment of 4-DOF SCARA robot, KIRO-3, it is shown that both the error of joint angles and the positioning error of end effector are drop to 15$\%$. These results are similar to those of other calibration methods, but the number of measurement is remarkably decreased by the suggested compensation method.

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