• Title, Summary, Keyword: Virtual primary core

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Thrust Performance Improvement of a Linear Induction Motor

  • Lee, Hyung-Woo;Park, Chan-Bae;Lee, Byung-Song
    • Journal of Electrical Engineering and Technology
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    • v.6 no.1
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    • pp.81-85
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    • 2011
  • The end effect of a linear induction motor (LIM) has been known for several decades, especially in high speed operation. The exit part of the primary is not dealt as extensively as the entry part because of its minor effect. However, the exit part is one of the keys to weaken the dolphin effect, which occurs in high speed operation. In this paper, the concept of the virtual primary core is introduced, and chamfering of the primary outlet teeth is proposed to minimize the longitudinal end effect at the exit zone. For this, LIM for the high-speed train is designed and analyzed by using finite element method. Results confirm that chamfering can improve thrust performance effectively.

Analysis of Static Characteristics of PMLSM Using Space Harmonic Analysis Considering Slot Structure (공간고조파법을 이용한 영구자석 선형 동기전동기의 슬롯을 고려한 정특성 해석)

  • Im, Gi-Chae;Hong, Jeong-Pyo;Kim, Gyu-Tak
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.48 no.4
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    • pp.145-151
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    • 1999
  • This paper presents the characteristic analysis method of PMLSM based on the Space Harmonic Analysis method considering the effect of stator slots. The magnetic field for unslotted primary can be easily calculated by the conventional space harmonic analysis method and the resultant magnetic field including slot effect is obtained using the concept of the virtual Equivalent Magnetizing Current(EMC) on primary core. And the influence of space harmonics in airgap flux density and static thrust due to slots is evaluated. In this paper, the results of the analytical method are compared with not only the experimental ones but ones of FEM to verify the validity of the proposed method.

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A Study on the Learner Characteristics in Virtual Reality by a School Level Curriculum (가상현실 교육에서 학교 급별 교육과정의 특성에 대한 연구)

  • Nam, Choong Mo;Kim, Chong Woo;Hong, Kyoung sun;Cho, Chino;Hong, Joo hee
    • Journal of The Korean Association of Information Education
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    • v.24 no.1
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    • pp.71-78
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    • 2020
  • To maximize educational effect with new educational methods in the 4th Industrial Revolution era, immersive education has become the core type of education and virtual reality (VR) is at the center of realistic content. VR education is increasing in school, but researches on VR production education are insufficient. Our study has proposed a school-level curriculum for students to create their own VR content. The output and the survey results were analyzed to find out the learner characteristics of elementary school students, middle school students, and pre-service teachers at each school level. As a result, there were some noticeable differences in concentration, content subject, and production time according to school level. Primary school students focused on their subjects, middle school students related to learning, and pre-service teachers put top priority on contents useful for primary education.

Characteristic Analysis and Static Tests of a Flat Moving Core Type LOA (평판 철심가동형 LOA의 특성해석 및 정특성 시험)

  • Jang, S.M.;Jeong, S.S.;Jeong, J.M.;Kim, H.K.;Wu, J.S.
    • Proceedings of the KIEE Conference
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    • pp.52-54
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    • 1998
  • LOA is the linear electromechanical device that mover is similar to secondary conductor of LIM. The mover reciprocates along stroke by supplying the alternating current to primary coil. LOA is the simpler and more efficient than other linear apparatus using the rotary motor because LOA produce the thrust force without any mechanical converter such as cam, clutch, belt, rack and pinion, etc. This paper deals with the static characteristics of moving coil type LOA by virtual work method, FEM analysis and experiment Results show that thrust force increases when mover travels form center to both ends.

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Virtual Ground Based Augmentation System

  • Core, Giuseppe Del;Gaglione, Salvatore;Vultaggio, Mario;Pacifico, Armando
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.2
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    • pp.33-37
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    • 2006
  • Since 1993, the civil aviation community through RTCA (Radio Technical Commission for Aeronautics) and the ICAO (International Civil Air Navigation Organization) have been working on the definition of GNSS augmentation systems that will provide improved levels of accuracy and integrity. These augmentation systems have been classified into three distinct groups: Aircraft Based Augmentation Systems (ABAS), Space Based Augmentation Systems (SBAS) and Ground Based Augmentation Systems (GBAS). The last one is an implemented system to support Air Navigation in CAT-I approaching operation. It consists of three primary subsystems: the GNSS Satellite subsystem that produces the ranging signals and navigation messages; the GBAS ground subsystem, which uses two or more GNSS receivers. It collects pseudo ranges for all GNSS satellites in view and computes and broadcasts differential corrections and integrity-related information; the Aircraft subsystem. Within the area of coverage of the ground station, aircraft subsystems may use the broadcast corrections to compute their own measurements in line with the differential principle. After selection of the desired FAS for the landing runway, the differentially corrected position is used to generate navigation guidance signals. Those are lateral and vertical deviations as well as distance to the threshold crossing point of the selected FAS and integrity flags. The Department of Applied Science in Naples has create for its study a virtual GBAS Ground station. Starting from three GPS double frequency receivers, we collect data of 24h measures session and in post processing we generate the GC (GBAS Correction). For this goal we use the software Pegasus V4.1 developed from EUROCONTROL. Generating the GC we have the possibility to study and monitor GBAS performance and integrity starting from a virtual functional architecture. The latter allows us to collect data without the necessity to found us authorization for the access to restricted area in airport where there is one GBAS installation.

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Pharmacophore Modeling, Virtual Screening and Molecular Docking Studies for Identification of New Inverse Agonists of Human Histamine H1 Receptor

  • Thangapandian, Sundarapandian;Krishnamoorthy, Navaneethakrishnan;John, Shalini;Sakkiah, Sugunadevi;Lazar, Prettina;Lee, Yu-No;Lee, Keun-Woo
    • Bulletin of the Korean Chemical Society
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    • v.31 no.1
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    • pp.52-58
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    • 2010
  • Human histamine H1 receptor (HHR1) is a G protein-coupled receptor and a primary target for antiallergic therapy. Here, the ligand-based three-dimensional pharmacophore models were built from a set of known HHR1 inverse agonists using HypoGen module of CATALYST software. All ten generated pharmacophore models consist of five essential features: hydrogen bond acceptor, ring aromatic, positive ionizable and two hydrophobic functions. Best model had a correlation coefficient of 0.854 for training set compounds and it was validated with an external test set with a high correlation value of 0.925. Using this model Maybridge database containing 60,000 compounds was screened for potential leads. A rigorous screening for drug-like compounds unveiled RH01692 and SPB00834, two novel molecules for HHR1 with good CATALYST fit and estimated activity values. The new lead molecules were docked into the active site of constructed HHR1 homology model based on recently crystallized squid rhodopsin as template. Both the hit compounds were found to have critical interactions with Glu177, Phe432 and other important amino acids. The interpretations of this study may effectively be deployed in designing of novel HHR1 inverse agonists.