• Title/Summary/Keyword: Mechanical traction

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A Study on the Optimal Design for DC traction system of Light Rail Transit (경전철 급전시스템의 최적설계에 관한 연구)

  • Jeon, Yong-Joo;Cho, Sung-Joon;Baek, Byung-San;Kim, Kuk-Jin;Kim, Jong-Koo
    • Proceedings of the KIEE Conference
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    • 2001.07b
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    • pp.1251-1253
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    • 2001
  • This paper presents on capacity design of DC-fed-traction system. The system is introduced including a characteristics of train, feeding network configuration, and design method of substation arrangements. Optimal design procedures is described, and program for capacity computation of the system is presented using the nodal equation, K.C.L, K.V.L, Ohm's law and superposition theory. For the proof of the proposed algorithm, we accomplished the simulation of DC traction system for HA-Nam LRT. By considering whole component in DC traction system the conclusion will be much precise.

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The Effectiveness of Mechanical Traction Therapy for Patients with Carpal Tunnel Syndrome (손목굴 증후군 환자를 위한 기계적 견인 치료의 효과)

  • Kyoung Sim Jung;Geum Sang Jeon;Sang Kun Sung;Bong Chun Noh;Tae Sung In
    • Journal of Korean Physical Therapy Science
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    • v.31 no.3
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    • pp.100-108
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    • 2024
  • Background: This study was conducted to investigate the effects of mechanical traction therapy on pain, symptom severity, and functional status in patients with carpal tunnel syndrome. Design: Randomized controlled trial study. Methods: The 24 participants in this study were randomly assigned to either the Mechanical traction therapy (MTT) group (n=12) or the placebo group (n=12). Both groups performed tendon and neural gliding exercise. Both groups underwent mechanical traction therapy with their forearms placed on a traction device. However, in the placebo group, the device was turned off, and a placebo treatment was administered without any mechanical stimulation. All the participants underwent 18 sessions of intervention (10 minutes, 3 days per week for 6 weeks). Both groups were assessed for pain using the numerical pain rating scale and for symptom severity and functional status using the Boston Carpal Tunnel Syndrome Questionnaire (BCTQ), which includes two additional scales: the Boston Symptom Severity Scale (BSSS) and the Boston Functional Status Scale (BFSS). Results: The muscle activation, pain, symptom severity, and functional status in the MTT group were significantly improved compared to the placebo group (p<0.05). Conclusion: The results of this study indicate that traction therapy combined with tendon and neural gliding exercise. are a beneficial method for improving pain, symptom severity, and functional status in patients with carpal tunnel syndrome.

An Experimental Study on the Characteristics of Friction Between a Moving Web and a Roller (이송중인 웹과 롤러간의 마찰 특성에 관한 실험적 연구)

  • Kwon, Soon-O;Shin, Kee-Hyun;Hahn, Young-Ho;Kim, Hyo-Sub
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.5
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    • pp.165-170
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    • 2001
  • In the continuos process systems, traction between a moving web and rollers is one of key mechanisms for the study of major issues including the distributed control of tension, guiding, wrinkling, winding, and scratching. Energy is transferred from the driven rollers to the web and from the web to the idle rollers through traction. The characteristics of friction play major role in the determination of the traction force between the moving web and the rollers. In this paper the characteristics of friction between the moving web and the rollers are studied. A procedure to determine the friction coefficient between the moving web and rollers is developed. An experimental setup to validate the procedure is devised. Experimental results showed that the value of traction coefficient decreases as the operating web speed increases and increases as the operation web tension increase.

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Cervical Traction: Review of Literature and Treatment Guidelines (경추견인: 문헌고찰과 치료지침)

  • Kim Han-Soo;Lee Yong-Deok;Kwon Won-An
    • The Journal of Korean Physical Therapy
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    • v.14 no.3
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    • pp.24-44
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    • 2002
  • Traction has been used since ancient times in the treatment of painfull spinal conditions, but the literature on traction and its clinical effectiveness Is limited. Traction can be defined as a drawing or pulling tension applied to a body segment. Cervical traction is a technique that applies a longitudinal force of the cervical spine and associated structures. Goals of traction include reduction of radicular signs and symptoms associated with conditions such as disk protrusion, degenerative disk disease, lateral stenosis, muscle spasm, and subluxations. The various mechanical factors most relevant to cervical traction are organized and discussed. The factors presented are 1) angle of pull, 2) Traction force, 3) duration of traction, 4) neck position and clinical application, and 5) frequency of treatment. It should allow physical therapists to adjust traction protocol to match the patient's symptoms and diagnosis. The purpose of this study is to provide a comprehensive overview of the cervical traction and treatment guidelines.

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The Effect of Mechanical Traction on Pain and Physical Function in Patients With Knee Osteoarthritis (기계적 견인이 슬관절 골관절염 환자의 통증과 신체 기능에 미치는 효과)

  • Lee, Nam-yong;Kwon, Chun-suk;Kim, Suhn-yeop
    • Physical Therapy Korea
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    • v.22 no.3
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    • pp.23-32
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    • 2015
  • The purpose of this study was to identify the effects of mechanical traction applied to the knee joint on pain, knee range of motion (ROM), timed up and go (TUG) and Western Ontario and MacMaster Universities Osteoarthritis (WOMAC) in patients with knee osteoarthritis (KOA) of Kellgren-Lawrence radiological rating scale II or III. Twenty three patients participated in the experiment for a period of four weeks. After baseline assessment, the patients with KOA were randomized into two groups: the traction group ($n_1=12$), which received traction with general physical therapy; and the control group ($n_2=11$), which received general physical therapy only on unilateral knee joints. Patients received interventions once a day, three times a week, for four weeks. Wilcoxon signed-rank test was used to analyze the change of dependent variances within the group during pre and post intervention. Mann-Whitney U test was used to analyze the change of dependent variances as TUG and passive ROM between the two groups. Analysis of covariance was used to analyze the change of dependent variances as numeric pain rating scale (NPRS) and WOMAC score between the two groups. In Wilcoxon signed-rank test, the traction group improved significantly with regard to NPRS (p<.01), passive knee flexion ROM (p<.01), passive knee extension (p<.05), TUG (p<.01) and WOMAC scores (p<.01) after intervention for four weeks, but not for the control group. In the Mann-Whitney U test and analysis of covariance, no significant difference was seen among all the dependent variances after intervention for four weeks between the two groups. These outcomes suggest that further studies should be carried out to determine the effects of mechanical traction prior to using it for the treatment of patients with knee osteoarthritis.

A study of traction motor for Bimodal low floor vehicle (바이모달 저상굴절차량용 견인전동기 설계에 관한 고찰)

  • Choi, Yeol-Jun;Park, Yeong-Ho;Choi, Jong-Mook;Mok, Jai-Kyun
    • Proceedings of the KSR Conference
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    • 2007.05a
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    • pp.911-915
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    • 2007
  • This paper deal with the design concept of traction motor for Bimodal low floor vehicles that are CNG(Compressed Natural Gas) hybrid bus and Fuel-cell bus. The design concept of the traction motor is studied in terms of electrical characteristics and mechanical construction. Finally, this paper introduces the characteristic of the traction motor for low floor vehicles which are applied in the world, and mentioned the detail design concept of traction motor.

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Cervical Range Of Motion Changes After Cervical Mobilization And Mechanical Traction (경추의 도수치료와 기계적 견인이 경추 가동범위에 미치는 영향)

  • Kim Hyoung-Soo;Ahn Mock;Hyoung In-Hyouk;Kim Eun-Young;Lee Hae-Jung;Bae Sung-Soo
    • The Journal of Korean Physical Therapy
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    • v.16 no.4
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    • pp.283-296
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    • 2004
  • Joint mobilization and mechanical traction are common treatment forms for mechanical cervical spine problem. The purpose of the study was to investigate the effectiveness of cervical mobilization and mechanical traction on active range of motion of cervical spine. Sixty volunteers, aged between 21 and 24 years (mean age 22), were recruited. Each subject was divided into one of three groups; mechanical traction, general coordinative manipulation, and mobilization group. Active range of motions in the cervical were measured before and after each treatment technique from each subject on the three occasions. In the cervical range of motion, all subjects regardless treatment technique showed significantly increasing ranges after applied treatment technique in all directions except extension and left rotation in the mobilization group.

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Design to Reduce Cost and Improve the Mechanical Durability of IPMSM in Traction Motors

  • Lee, Ki-Doek;Lee, Ju
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.28 no.5
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    • pp.106-114
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    • 2014
  • The interior permanent-magnet synchronous motor (IPMSM) is often used for the traction motor of hybrid electric vehicles (HEVs) and electric vehicles (EVs) due to its high power density and wide speed range. This paper introduces the 120kW class IPMSM for traction motors in military trucks. This system, as a SHEV (series hybrid electric vehicle), requires a traction motor that can generate high torque. This study introduces a way to reduce costs by proposing a design approach that creates reluctance torque that can be maximized by varying the dq-axis inductance. If a model designed by a design approach meets the desired torque, the magnetic torque can be reduced by an amount equal to the increase in reluctance torque and consequently the amount of permanent magnets can be reduced. A reduction gear and high speed operation of motors are necessary for the miniaturization of the motor. Thus, a fairly large centrifugal force is generated due to the high speed rotation. This force causes mechanical interference between the rotor and the stator, and a design approach for adding an iron bridge is explained to solve the interference. In this study, the initial model and the improved model that reduces cost and improves mechanical durability are compared by FEA, and the models are produced. Finally, the FEM results were verified experimentally.

Effect of Metal Removal and Traction Force on Contact Fatigue Life (견인력과 접촉표면 제거가 접촉피로수명에 미치는 영향)

  • Seo Jung-Won;Hur Hun-Mu;Choi Jae-Boong;Kim Young-Jin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.10 s.241
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    • pp.1384-1391
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    • 2005
  • Damage often occurs on the surface of railway wheels due to wheel-rail contact fatigue. It should be removed before reaching wheel failure, because wheel failure can cause derailment with loss of life and property. The increase or decrease of the contact fatigue lift by the metal removal of the contact surface were investigated by many researchers, but they have not considered initial residual stress and traction force. The railway wheel has the initial residual stress formed during the manufacturing process, and the residual stress is changed by thermal stress induced by braking. The traction force and residual stress are operated on wheels of locomotive and electric motor vehicle. In this study, the effect of metal removal depth on the contact fatigue life for a railway wheel has been evaluated by applying lolling contact fatigue test. The effect of the traction force and metal removal on the contact fatigue life has been estimated by finite element analysis. It has been found that the initial residual stress determines the amount of metal removal depth if the traction coefficient is less than 0.15. If the traction coefficient is greater than 0.2, however, the amount of metal removal depth is independent on the intial residual stress.

A Study on Development of Real-Time Simulator for Electric Traction Control System (TCS(Traction Control System)을 위한 실시간 시뮬레이터 개발에 관한 연구)

  • Kim, Tae Un;Cheon, Seyoung;Yang, Soon Young
    • Journal of Drive and Control
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    • v.16 no.3
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    • pp.67-74
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    • 2019
  • The automotive market has recently been investing much time and costs in improving existing technologies such as ABS (Anti-lock Braking System) and TCS (Traction Control System) and developing new technologies. Additionally, various methods have been applied and developed to reduce this. Among them, the development method using the simulation has been mainly used and developed. In this paper, we have studied a method to develop SILS (Software In the Loop Simulation) for TCS which can test various environment variables under the same conditions. We modeled hardware (vehicle engine and ABS module) and software (control logic) of TCS using MATLAB/Simulink and Carsim. Simulation was performed on the climate, road surface, driving course, etc. to verify the TCS logic. By using SILS to develop TCS control logic and controller, it is possible to verify before production and reduce the development period, manpower and investment costs.