• Title/Summary/Keyword: IM

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Modified Direct Torque Control System of Five Phase Induction Motor

  • Kim, Nam-Hun;Kim, Min-Huei
    • Journal of Electrical Engineering and Technology
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    • v.4 no.2
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    • pp.266-271
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    • 2009
  • In this paper, improved direct torque control(DTC) of five-phase induction motor(IM) is proposed. Due to the additional degrees of freedom, five-phase IM drives present unique characteristics. One of them is the ability of enhancing the torque producing capability of the motor. Also five-phase motor drives possess many others advantage compared with the traditional three-phase motor drives. Such as, reducing the amplitude and increasing of frequency of torque pulsation, reducing amplitude of current per phase without increasing the voltage per phase and increasing the reliability. The direct torque control method is advantageous when it is applied to the five-phase IM. Because the five-phase inverter provides 32 space vectors in comparison to 8 space voltage vectors by the three-phase inverter. The 32 space voltage vectors are divided into three groups according to their magnitudes. The characteristics and dynamic performance of traditional five-phase DTC are analyzed and new DTC for five-phase IM is proposed. Therefore, a more precise flux and torque control algorithm for the five-phase IM drives can be suggested and explained. For presenting the superior performance of the pro-posed direct torque control, experimental results is presented using a 32 bit fixed point TMS320F2812 digital signal processor

Comparision in Emission Inspection System of a Gasoline Vehicle in Service (운행 휘발유 자동차의 배출가스검사 시스템 비교)

  • Oh, Sangyeob;Park, Wondeok
    • Transactions of the Korean Society of Automotive Engineers
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    • v.22 no.1
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    • pp.1-7
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    • 2014
  • In the most of a nation, the safety and emission gas inspection system of a vehicle in service have been conducted with the most compatible inspection system according to its real environmental situation. Especially, the state of vehicle emission gas is measured by advanced emission gas inspection equipment. It has the problem that the decrease effect of an environmental pollution matter is not calculated by weight percent measurement type equipment. Therefore, in this study, the correlations for the results of emission gas measurement are analyzed by comparing a weight percent measurement type (IDLE+ASM2525 mode) and an advanced mass measurement type (IM240 mode). As the result, the selectivity of an emission gas by IM240 mode is higher than that by IDLE+ASM2525 mode. In the future, therefore, the introduction of IM240 mode and a mass measurement type equipment are necessary. Also, we need to prepare a vehicle emission gas inspection system for introducing IM240 mode.

Applications of bridge information modeling in bridges life cycle

  • Marzouk, Mohamed M.;Hisham, Mohamed;Al-Gahtani, Khalid
    • Smart Structures and Systems
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    • v.13 no.3
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    • pp.407-418
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    • 2014
  • The purpose of this paper is to present an Integrated Life Cycle Bridge Information Modeling that can be used throughout different phases of the bridge life cycle including: design, construction, and operation and maintenance phases. Bridge Information Modeling (BrIM) has become an effective tool in bridge engineering and construction. It has been used in obtaining accurate shop drawings, cost estimation, and visualization. In this paper, BrIM is used as an integrated tool for bridges life cycle information modeling. In the design phase, BrIM model can be used in obtaining optimum construction methods and performing structural advanced analysis. During construction phase, the model selects the appropriate locations for mobile cranes, monitors the status of precast components, and controls documents. Whereas, it acts as a tool for bridge management system in operation and maintenance phase. The paper provides a detailed description for each use of BrIM model in design, construction, and operation and maintenance phases of bridges. It is proven that BrIM is an effective tool for bridge management systems throughout their life phases.

Atypical Intramuscular Myxoma of the Lumbosacral Paraspinal Muscle : The First Case Report in Asian

  • Choi, Doo Yong;Kim, Jong Tae;Kim, Jiyoung;Lee, Ho Jin
    • Journal of Korean Neurosurgical Society
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    • v.58 no.6
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    • pp.566-570
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    • 2015
  • Intramuscular myxoma (IM) is a benign neoplasm of mesenchymal origin. We report a rare case of IM which was located in the lumbosacral paraspinal muscles. A 62-year-old female patient presented with progressive low back pain for 2 months, and the radiologic findings showed a large mass ($4.0{\times}3.5{\times}6.5cm$) in the right lumbosacral paraspinal area. Total resection of the tumor was performed and the symptom was nearly resolved after surgery. Although the immuno-histopathological analysis was consistent with IM, there were some different findings from typical pathological characteristics of IM in this case. Firstly, the symptomatic change of the mass took relatively short time (less than 3 months), and this change was accompanied by partial calcification inside the mass. Moreover, iatrogenic interruption of paravertebral muscle by the other previous operation might be the promoting factor of the fibrous dysplasia, which can explain the pathogenesis of IM. To our knowledge, this is the eighth case of the lumbar paraspinal myxoma reported in the literatures and the first case in Asian population.

Optical packaging technology and characterization of analog PIN-Photodiode (Analog용 PIN-Photodiode의 광 패키징 기술 및 특성 연구)

  • Lee Chang Min;Kwon Kee Young
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.42 no.3 s.333
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    • pp.17-24
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    • 2005
  • We fabricated PIN-Photodiodes with a single mode fiber for analog communications and analyzed characteristics of the devices. The fabricated PIN-Photodiode shows a bandwidth of 1.5 GHz, a dark current of 20 p4 a capacitance of 0.48 pF, and the responsivity of 0.9 V/W, a second order distortion of -72 dBc. In this paper, we developed a new optical Packaging technology that is aligning in real-time monitoring of both responsivity and IM2 characteristics. As a result responsivity has been improved by 0.03 V/W, and also U has been improved by $3\~5\;dBc$. On the other hand, failure ratio has been reduced by $3.5\%$.

Informationsstrukturelle Effekte von Scrambling im Deutschen (도이치말 문장성분 뒤섞기의 '정보포장' 효과)

  • Kang Byong-Chang
    • Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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    • v.1
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    • pp.349-374
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    • 1999
  • In der vorliegenden Arbeit wird versucht, die Verhaltnisse yon Informationsstrukturierung (information packaging) und Scrambling am Material des Deutschen zu untersuchen. Bei der Informationsstrukturierung geht es um die Ordnung der Elemente des Satzes, die durch die Kommunikationssituation, die Intentionen des Sprechers sowie seine Kenntnisse und Annahmen tiber $Wissensvorr\"{a}te\;des\;H\"{o}rers$ determiniert wird. Deutsch ist eine Sprache mit 'freier' Abfolge der Satzglieder. Die Grammatik des Deutschen erlaubt $S\"{a}tze$, die dasselbe bedeuten und sich in ihrer Konstituentenfolge unterscheiden. Diese variable Wortfolge (Topikalisierung und Scrambling) und der Satzakzent im Deutschen wirken systematisch mit der Informationsstruktur (Topik­Pradikation-Struktur und Fokus-Hintergrund-Struktur) zusammen. Es ist allgemein bekannt, $da\ss$ Scrambling und Topikalisierung sowohl diskurssemantische als auch informationsstrukturelle Effekte $ausl\"{o}sen$. In der vorliegenden Arbeit wird zuerst auf problematische Aspekte der $Ans\"{a}tze$ hingewiesen, die Scrambling mit (diskurs-)semantischen Begriffen wie 'Definitheit', $'Spezifit\"{a}t'\;oder\;'Familiarit\"{a}t'$ sowie mit der traditionellen 'Thema-Rhema-Gliederung' zu erklaren versuchen. Dann wird Scrambling unter Bezug auf den Zusammenhang zwischen Fokus-Hintergrund-Struktur und grammatischer Struktur behandelt. Dabei wird festgestellt, dass Satzakzent und Scrambling systematisch mit der Fokus-Hintergrund-Gliederung des Informationsbereiches im Satz interagieren und dass die $Umstellungsm\"{o}glichkeiten$ im Mittelfeld zur $\"{A}nderung$ der Fokusprojektion, d.h. zur Umordnung von Hintergrund-Teil und Fokus-Teil $f\"{u}hren$. Scrambling kann dazu im Zusammenwirken mit dem Satzakzent und einem bestimmten Intonationsmuster einen 'Kontrasttopik' - Effekt $ausl\"{o}sen$.

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A Direct Torque Control System for Improving Speed Response of Five-Phase Induction Motor (5상 유도전동기의 속도응답특성 개선을 위한 직접토크제어 시스템)

  • Kim, Min-Huei;Choi, Sung-Un
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.1
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    • pp.66-74
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    • 2012
  • This paper propose a improved direct torque control(DTC) system for improving operation of five-phase squirrel-cage induction motor(IM). A five-phase IM drives present unique characteristics due to the additional degrees of freedom and also drives possess many others advantage compared with the traditional three-phase motor drive system, such as reducing a amplitude of torque pulsation and increasing the reliability. In order to maximize the torque per ampere, the proposed motor has concentrated windings and the produced back-electromotive force(EMF) is almost trapezoidal, and the motor is supplied with the combined sinusoidal plus third harmonic of currents, there is necessary to controlled 3rd harmonic current. Also a DTC method is advantageous when it is applied to the five-phase IM, because the five-phase inverter provides 32 space vectors in comparison to 8 space voltage vectors into the three-phase inverter drive system. For presenting the superior performance of the proposed DTC, experimental results of speed control are presented using a 32-bit fixed point TMS320F2812 DSP with 1.5[hp] IM.

The Effect of Supervisor-Focused Impression Management Behavior of the Cabin Crew on Perceived Customer Empathy

  • LEE, Sung-Heun;HWANG, Hee-Joong
    • Journal of Distribution Science
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    • v.18 no.10
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    • pp.77-87
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    • 2020
  • Purpose: This study was done to analyze the effect of supervisor-focused impression management behavior of the airline cabin crew on perceived customer empathy. It focused on verifying dual meanings of the crew's emotional expression divided into surface acting and deep acting. Research design, data and methodology: The survey was conducted on cabin crews of two major Korean airlines. The reliability and validity of each variable used in the questionnaire were verified. Then, each hypothesis was analyzed through multiple regression analysis. Results: Firstly, the crew's supervisor-focused impression management behavior had a significant effect only on surface acting of the crew's emotional labor behavior. Among the crew's supervisor-focused IM behaviors, verbal IM behavior had a greater influence on surface acting than non-verbal IM behavior. Secondly, there was no relationship between the crew's supervisor-focused IM behavior and the crew's deep acting. Thirdly, the crew's emotional labor behavior (surface acting & deep acting) had a significant effect on perceived customer empathy. Fourth, the crew's deep acting had a greater influence on perceived customer empathy than surface acting. Conclusions: Cabin crews receive double evaluation from their immediate supervisors and customers. As a result, it was confirmed that the crew's supervisor-focused IM behavior, the crew's emotional labor behavior, and perceived customer empathy were connected process.

A STUDY ON THE FIXAT10N OF MENTHOL BY CLINOPTILOLITES (Clinoptilolite의 Menthol보유성에 관한 연구)

  • 양광규;조성희
    • Journal of the Korean Society of Tobacco Science
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    • v.6 no.2
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    • pp.117-129
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    • 1984
  • In this study, clinoptilolites were subjected to an array of experimental conditions, such as variations in heating temperature, reaction time, and molarity of acid and bass, and their responses measured. The activation levels were measured by adsorption indexes of toluene and ethyl alcohol and the X-ray spectra of clinoptilolites treated with acid and base. The effect of clinoptilolites on the menthol fuation was estimated by the amount of menthol produced after a given time of storage. The results were as follows: The optimum conditions for the clinoptilolites treatment were found to be IM HCI, IM NaOH, IMHCl-lM NaOH, and IM NaOH-lM HCl at $100^{\circ}C$ for 2 hours. 2. It was noted that clinoptilolites, untreated or treated with HCl, could not be used for the menthol fixation since the catalytic crating of menthol occurred with them. 3. The results from the residual menthol measurement in clinoptilolites after a specific period of storage showed that the best menthol fixation occurred in those treated with IM NaOH. 4. The menthol fuation by cigarettes with mentholated clinoptilolites was far better than that obtained by the use of mentholated tobacco column. 5. Most components in cigrettes smoke were generally reduced by the adsorption to clinoptilolites treated with IM NaOH.

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Performance Analysis of Indoor/Outdoor Visible Light Communication System Influenced by External Noise Light (외부광잡음에 의한 실내외 가시광 무선통신 성능 변화 분석)

  • Yang, Se-Hoon;Kim, Deok-Rae;Kim, Hyun-Seung;Son, Yong-Hwan;Han, Sang-Kook
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.12B
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    • pp.1595-1600
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    • 2011
  • We analyzed the noise effect from artificial light and sunlight on the signal performance in visible light communication systems based on Intensity Modulation/Direct Detection(IM/DD). System performance was experimentally demonstrated by transmitting 50ksysmbol/s QPSK signals at 2MHz sub-carrier. And received signals were analyzed using EVM and RF spectrum. Finally, the system performance was improved by utilizing a visor and we confirm that the outdoor visible light communication was possible using IM/DD method.