• Proceedings of the KSR Conference
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• 2002.10a
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• pp.427-433
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• 2002

An inverter-driven induction motor is usually adapted to the traction motor for a high speed drive system requiring safety, reliability, performance, compact size owing to the space and weight alloted for attaching to train, etc. and AC Traction motor for G7 train will be operated in the worst condition such as mechanical vibration, limited mounting space, severe thermal stress, inverter with non-sinusoidal voltage waveform, dust and so on. therefore, design procedure must be carefully carried out wi th considering the motor size, vibration and thermal expansion of rotor bars, insulation system, reliability of frame, as well as output characteristics. In this paper, we will inform the characteristics and design of the traction motor for G7 train and also analyze the test result of it.

• Journal of Oral Medicine and Pain
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• v.47 no.2
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• pp.95-101
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• 2022

Temporomandibular joint osteoarthritis (TMJ OA) causes destruction of the temporomandibular joint (TMJ) and can lead to occlusal changes such as anterior open bite in some patients. Consequently, these patients may experience difficulty in chewing food items and exhibit abnormal functional habits such as bruxism, preventing healing of the TMJ condyles. Treatment protocols include the use of traction appliances to reduce stress on the condyles. Unstable occlusions can lead to weakness of the masticatory muscles which, in turn, worsen the occlusal changes and complicate pain management. Therefore, the current study evaluated the condition of the masseter muscle using ultrasonography and educated patients on the execution of gum-chewing exercises for muscle strengthening. It also aimed to assess the effects of traction appliances and strengthening exercises on the masticatory muscles of patients with occlusal changes caused by TMJ OA.

• Korea-Australia Rheology Journal
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• v.19 no.4
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• pp.211-219
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• 2007

Here we demonstrate complex transient behavior of viscoelastic liquid described numerically with the Leonov model in straight and contraction channel flow domains. Finite element and implicit Euler time integration methods are employed for spatial discretization and time marching. In order to stabilize the computational procedure, the tensor-logarithmic formulation of the constitutive equation with SUPG and DEVSS algorithms is implemented. For completeness of numerical formulation, the so called traction boundaries are assigned for flow inlet and outlet boundaries. At the inlet, finite traction force in the flow direction with stress free condition is allocated whereas the traction free boundary is assigned at the outlet. The numerical result has illustrated severe forward-backward fluctuations of overall flow rate in inertial straight channel flow ultimately followed by steady state of forward flow. When the flow reversal occurs, the flow patterns exhibit quite complicated time variation of streamlines. In the inertialess flow, it takes much more time to reach the steady state in the contraction flow than in the straight pipe flow. Even in the inertialess case during startup contraction flow, quite distinctly altering flow patterns with the lapse of time have been observed such as appearing and vanishing of lip vortices, coexistence of multiple vortices at the contraction comer and their merging into one.

• Korean Journal of Acupuncture
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• v.29 no.3
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• pp.385-395
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• 2012

Objectives : Meridian sinew theory was introduced in Miraculous Pivot, Huangdi's Internal Classic, to explain in relation with locations of meridian sinews, causes, mechanisms, and treatment of diseases. The meridian sinews are understood to include muscles, tendons and ligaments, or muscles in the superficial body made up with muscles, ligaments, tendons, fascia etc. This theory shows the similarity or organic relationship between the meridian sinews and muscles. From the Hippocrates(460-385 BC) ages, traction therapy was used as a treatment method on muscular diseases such as low back pain, scoliosis, etc in western medicine. The effects of traction therapy, however, were unclear so that this study was purposed to illustrate the effectiveness of continuous traction therapy and to develop meridian sinews treatment. Methods : We made 2 hypotheses to explain the cause of scoliosis occurrence, muscles contraction and relaxation. As the hypothesis, we made the spinal model having 3 joints with wood and rubber bands. Each of the three joints in the spinal model represents the case of normal(NT; control), contraction(AT 1)and relaxation(AT 2) condition, and distance between the vertebrae joints was measured. Results : Under normal circumstance models, the normal type 1(NT 1; muscle relax state) and normal type 2(NT 2; muscle contract state) all joints were being towed equally. But in an unusual contracted situation, regardless of the relationship of joint area, contracted part of joint was not released. And in a relaxed situation, regardless of joint areas, released parts of joint were further released. These observation results mean that the effects of traction might be different from the purpose of traction therapy of Hippocrates. Conclusions : To explain the effect of traction therapy for scoliosis, the spinal cord model and scoliosis model were made. After vertebral bodies were pulled with different tensile forces, we compared the observed length of the each joints pulled. The results suggested that there were no effects of traction in objected parts with traction method from Hippocrates' design, continuous traction method. Moreover, it may worsen the symptom in worst case. Of course, our results are just the result of experimental models and clinical results may be different. More careful studies, therefore, are required.

• Journal of Yeungnam Medical Science
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• v.38 no.2
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• pp.152-156
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• 2021

Diplopia is a rare complication of spine surgery. The abducens nerve is one of the cranial nerves most commonly related to diplopia caused by traction injury. We report a case of a 71-year-old woman who presented with diplopia developing from abducens nerve palsy after C1-C2 fixation and fusion due to atlantoaxial subluxation with cord compression. As soon as we discovered the symptoms, we suspected excessive traction by the instrument and subsequently performed reoperation. Subsequently, the patient's symptoms improved. In other reported cases we reviewed, most were transient. However, we thought that our rapid response also helped the patient's fast recovery in this case. The mechanisms by which postoperative diplopia develops vary and, thus, remain unclear. We should pay attention to the fact that the condition is sometimes an indicator of an underlying, life-threatening condition. Therefore, all patients with postoperative diplopia should undergo thorough ophthalmological and neurological evaluations as well as careful observation by a multidisciplinary team.

• Korean Journal of Mathematics
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• v.16 no.1
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• pp.25-40
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• 2008

We are concerned with a free boundary problem for the 2D Stokes channel flows, which determines the profile of the wing for the channel, so that the given traction force is to be distributed along the wing of the channel. Using the domain embedding technique, the free boundary problem is transferred into the shape optimization problem through the compliant formulation by releasing the traction condition along the variable boundary. The justification of the formulation will be discussed.

• Tribology and Lubricants
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• v.4 no.1
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• pp.30-35
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• 1988

Liquid crystals have some tribologically favorable lameliar structure. The Performance of ther mottopic liquid crystal was investigated under elastohydrodynamic condition in terms of traction and film thickness. It exhibited low traction and very thin film thickness, which were almost constant over the entire speed range measured. It was also found to have sealing effect like grease. This work has shown that there exists "potential" for using liquid crystals as lubricants.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.693-696
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• 2011

The SRM (Switched Reluctance Motor) is composed of silicon steel plates where the rotor structure is simple and laminated without coil winding or permanent magnet, making it mechanically robust and its maintenance and repair excellent. Applying SRM as traction motor for railway vehicle is given consideration because of its ruggedness capability in severe loading condition and its compact structure. Optimal design of SRM is needed to reduce torque ripple to apply SRM for railway traction drive because SRM has high torque ripple. In this paper, switched reluctance motor with three different stator pole shapes is taken for magnetic analysis using 3d finite element method to apply SRM as traction drive for railway vehicle. It is observed that the model 3 added Tooth Tang Depth and Slot Round to stator shape gives the improved inductance and torque characteristic.

• International Journal of Automotive Technology
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• v.1 no.1
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• pp.48-55
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• 2000

Two major roles of the traction control system (TCS) are to guarantee the acceleration performance and directional stability even in extreme road conditions, under which average drivers may not control the car properly. Commercial TCSs use experiential methods such as lookup table and gain-scheduling to achieve proper performance under various road and vehicle conditions. This paper proposes a new slip controller which uses the brake and the throttle actuator simultaneously. To avoid measurement problems and to get a simple structure, the brake controller and the throttle controller are designed using Lyapunov redesign method and multiple sliding mode control respectively. Through the hybrid use of brake and throttle controllers, the vehicle is insensitive to the variation of the vehicle mass, brake gain and road condition and can achieve the required acceleration performance. The proposed method is validated with simulations based on 15 DOF passenger car model.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.680-683
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• 1996

The dynamics of the vehicle system has highly nonlinear components such as an engine, a torque converter and variable road condition. This thesis proposes a Fuzzy Logic Algorithm that shows better control performance than Antiwindup PI in the highly nonlinear vehicle system. Traction Control System(TCS), which adjusts throttle valve opening by Fuzzy Logic Algorithm improves vehicle drivability, steerability and stability when vehicle is starting and cornering. When a throttle valve is opened at large degree, Fuzzy Logic Algorithm shows better performances like a small settling time and a small oscillation than Antiwindup PI in simulation. The decreased desired slip ratio improves steerability in the simulation when a vehicle is cornering. The Fuzzy Logic Algorithm has been tested by a 1/5-scale vehicle for tracking the constant desired velocity.