• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1395-1401
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• 2010

A paradigm shift in driving system of transportation vehicle from engine to electric motor is required as the problems on air pollution and drain of petroleum resource are on the rize. Moreover while it is possible to control the motor with variable frequency driver, the application of motor in various kinds of vehicles is spread rapidly. In the paper, the effective design method of IPMSM for EV and HEV by using equivalent magnetic circuit and finite element method (FEM) is suggested. First of all, load conditions of the application are calculated. And basic design process of IPMSM is proposed with two design point. Finally, in order to verify the proposed design process, it was compared with the basic design parameter and the FEM analysis results.

• Archives of Plastic Surgery
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• v.35 no.3
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• pp.349-353
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• 2008

Purpose: There are 3 well-known surgical procedures to treat Pierre Robin sequence: tongue-lip adhesion, distraction osteogenesis of mandible, and tracheostomy. The classical tongue-lip adhesion is an effective way to keep airway. The tongue, however, becomes quite non-mobile and appears dormant until the patient could control upper airway and the adhesion can be maintained for prolonged period. Most of all, this procedure does not provide the correction of the micrognathia. Distraction osteogenesis is a good technique to correct micrognathia and to prevent tracheostomies in patients with Pierre Robin sequence. But airway keeping procedure is needed during the distraction period. The purpose of this study is to determine the usefulness of temporary tongue-lip traction during the initial period of mandibular distraction in Pierre Robin sequence patients with severe airway problems requiring operative procedure. Methods: It was a prospective study of 2 Pierre Robin sequence patients aged between 4 months and 6 months requiring surgical procedure to correct recurrent and severe pulmonary complications. Two patients underwent distraction osteogenesis of mandible. During the operation, deep one tension suture was performed to tract the tongue and lip. When the patient gained control of upper airway at the initial period of distraction and micrognathia was corrected, the traction suture was removed. Results: All patients were followed up. No patients complained severe pulmonary complications and tracheostomy could be avoided. No patients had severe pulmonary complication. The pulmonary condition of patients was good. Conclusion: In severe Pierre Robin sequence case, temporary tongue-lip traction is a good assistant method in distraction osteogenesis because this method can avoid tracheostomy.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.5
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• pp.284-294
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• 2012

Objectives: The anterior open bite with temporomandibular disorders (TMD) is one of the most challenging cases both orthodontically and surgically. We introduce an intermaxillary traction treatment for patients with anterior open bite and TMD using a skeletal anchorage system (SAS). Materials and Methods: This study was comprised of 52 patients with anterior open bite and TMD. A total of four mini-screws were inserted, two screws each into the maxilla and mandible, to obtain a class II pattern of elastic application with 120-200 g force. Adjunctive muscle relaxation treatments, such as splint therapy, medication, and botulinum toxin injection were applied during or before intermaxillary traction. At least one treatment among adjunctive muscle relaxation treatment, mentioned above, was applied to 96.2% of patients. We evaluated the clinical characteristics of patients, TMD symptom changes, amount of open bite improved. The degree of open bite improvement was compared between the open bite-reduced group (21 patients) and not-reduced group (5 patients). Results: TMD symptoms (muscle/joint pain, joint sound, mouth opening) remained or improved in most patients, and worsened in about 10% of patients for each items. Anterior open bite was improved by a mean of 1.75 mm (P<0.01) during treatment. The open bite-reduced group exhibited a significant open bite improvement compared to the not-reduced group (P<0.05), with 37% of open bite improvement occurring during the first 3 months of treatment. Conclusion: The intermaxillary traction technique using SAS is a valid modality for correction of anterior open bite and improvement of TMD symptoms.

• Journal of the Korean Society of Radiology
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• v.7 no.1
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• pp.37-44
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• 2013

In study suggested clinical availability to shoulder forced traction method in term of quality of image, the patient's convenience and stability, according to whether to use of shoulder forced traction bend using computed tomography(CT) that X-ray calibration and various mathematic calibration algorithm application can be applied by AEC. To achieve this, 79 patients is complaining of cervical pain oriented that shoulder forced traction bend use the before and after acquires lateral projection scout image and transverse image. transverse image of a fixed size in concern field of pixel and figure the average HU value compare that quantitative analysis. Artifact and pixel and resolution to qualitative clinical estimation image analysis. the patient feel inconvenience degree that self-diagnosis survey that estimate. As a result, lateral projection scout image if you used shoulder forced traction bend for the depicted has been an increase in the number of a cervical vertebrae. transverse image concern field shoulder forced traction bend use the before and after for pixel and the average HU-value changes was judged to be almost irrelevant. Artifact and resolution and contrast, in qualitative analysis of the results relating the observer to the unusual result. So, the patients of 82.27% complained discomfort that use of shoulder forced traction bend in self-diagnosis survey. No merit of medical image by using of bend from result was analyzed quality of image to quantitative and qualitative method judged. Nowadays, CT is supplied possible revision of quality of radiation by reduction of slice and automatic exposure controller, etc and application of preconditioning filter process due to various mathematic revision algorithm. So, image noise by beam hardening artifact should not be a problem. shoulder forced traction bend of use no longer judged clinically availability because have not influence of image quality and give discomfort, have extra dangerousness.

• Journal of Power Electronics
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• v.16 no.4
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• pp.1245-1255
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• 2016

The single resonant inverter is widely employed in typical inductive power transfer (IPT) systems to generate a high-frequency current in the primary side. However, the power capacity of a single resonant inverter is limited by the constraints of power electronic devices and the relevant cost. Consequently, IPT systems fail to meet high-power application requirements, such as those in rail applications. Total harmonic distortion (THD) may also violate the standard electromagnetic interference requirements with phase shift control under light load conditions. A power regulation approach with selective harmonic elimination is proposed on the basis of a parallel multi-inverter to upgrade the power levels of IPT systems and suppress THD under light load conditions by changing the output voltage pulse width and phase shift angle among parallel multi-inverters. The validity of the proposed control approach is verified by using a 1,412.3 W prototype system, which achieves a maximum transfer efficiency of 90.602%. Output power levels can be dramatically improved with the same semiconductor capacity, and distortion can be effectively suppressed under various load conditions.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.1
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• pp.43-51
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• 1998

Most of fuel-injection system operated with mechanical methods are difficult to control the injection quantity and injection timing as well as injection rate exactly. Moreover high pressure injection scheme is never be realized with conventional one. On the other hand, serious air pollution can be lessened with injection system equipped with those functions. Therefore, electronically controlled Unit Injuctor(UI) appeared to satify above mentioned desires. However, it is still difficult that the most important part, especially solenoid valve, is analyzed precisely, because of the existence of complex combination of electromagnetics, electrics and dynamic problems. In this study, experimental and theoretical analysis are accomplished for understanding of solenoid valve characteristics and further its design. As the result, the follows are obtained 1) As the increase of wire diameter, the response time became shorter and optimal inductance existed in relative with the response time and wire diameter. 2) According to increasing input voltage, the traction force increased, otherwise the response time was shortened. 3) As the increase of armature stroke, the traction force decreased and the response time became longer.

• Journal of the Korean Society for Railway
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• v.9 no.4 s.35
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• pp.357-361
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• 2006

This paper dealt with the performance evaluation and the diagnostic techniques of lightning arresters for DC electric traction vehicle. Field Measurements on the protective operation of lightning arresters against surge currents were carried out on running vehicles to acquire the data necessary for the diagnosis. The frequency and the magnitude of surge events were analyzed. Surge currents of $1\sim3$ times were recorded in one running service route and their magnitudes were ranges of $150A\sim2kA$. Also, an acceleration experiment on a lightning arrester by the standard lightning impulse current of 8/20 us and 5 kA was performed to know the aging characteristics. After the surge current application of 3,000 times, the reference voltage decreased by 4.5 %, and the leakage current was below 10 uA at the continuous operating voltage and about 50 uA at the rated voltage. From the experimental results, we propose a decision level of leakage current for the arrester used in this paper and designed an arrester tester which analyzes arrester condition by the magnitude of leakage current.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.500-504
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• 1997

Current source inverter drives of auto sequentially commutated type are very popular in high power applications, because of simple power circuit configuration with four quadrant operation. But the six-step current output create harmonic problems and the input power factor of such a drive is not always good. In this respect pulse width modulated drives using gate turn off thyristors ( GTO ) are finding application, especially in traction drives. However the switching and snubber loses of a GTO do not permit the inverter switching frequency go beyond a few hundred hertz.This will again introduce low frequency harmonic problems. Multi level inverters of the 3-level and 5-level can be considered as an alternative to overcome the low switching frequency harmonic problem of the 2-level GTO inverters. But with multi level inverters the complexity of the power circuit increases. In this paper a combination of multi level ( 2-level and 3-level ) inverters and multi phase induction motor ( 3-phase and 6-phase) configurations are presented for high power VSI drives for traction applications with reduced inverter switching frequency requirements coupled with reduced voltage rating for the power switch.

• Archives of Craniofacial Surgery
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• v.16 no.3
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• pp.131-135
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• 2015

Background: Variable methods have been introduced for reduction of the zygomatic fractures. The Dingman elevator is used widely to reduce these fractures but is inappropriate in certain types of fractures which require atypical traction vectors. We introduce and examine an alternate method of reducing zygomatic fractures using wire and hook traction. Methods: A retrospective study was performed for all zygomatic fracture patients admitted between 2008 and 2014. Medially rotated fractures were reduced by using a wire looped through an intermaxillary screw secured on the medial side of the zygoma. Laterally rotated fractures were reduced using a hook introduced through an infrazygomatic skin incision. Results: No accidental bleeding or incomplete reduction was observed in any of the cases. Postoperative imaging demonstrated proper reduction immediately after the operation. Follow-up computed tomography study at 1 month after operation also demonstrated proper reduction and healthy union across the previous site of fracture. Conclusion: The hook and wire method allowed precise application of traction forces across zygomatic fractures. The fractured bone fragment could be pulled in the direction precisely opposite to the vector of impact at the time of trauma. Soft tissue damage due to dissection was minimized. In particular, this method was effective in reducing rotated bone fragments and can be an alternative option to using the zygoma elevator.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.7B
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• pp.601-607
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• 2008

The induced voltages by AT power feeding system of electrified traction line to telecommunication line are calculated with the method of multi-conductor line solution in the CCITT Directives. There is a screening effect by railway line itself among various shielding factors against induction. It is the argue point whether the multi-conductor line solution contains the railway line effect since the calculation method does not show any expression about shielding factors. So this paper illuminates the mysterious question by reviewing the shielding factor principle on traction system, scrutinizing the Japanese bible about induction, analyzing the multi-conductor line solution itself, and comparing the result calculation considering the effect of railway screen. This paper concludes that multi-conductor line solution contains the screening effect of railway lines.