• Title/Summary/Keyword: Sun Vector

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A Study of Attitude Determination Techniques for Satellite (위성체의 자세결정기법에 관한 연구)

  • Cho, K.R.;Suh, D.H.
    • Journal of Advanced Navigation Technology
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    • v.2 no.2
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    • pp.100-106
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    • 1998
  • The cone intercept method (CIM) is generally used for attitude determination of a spin-stabilized satellite. The method is popularly used on a transfer orbit, but it is well known that it can also be used for the geosychronous orbit. In this paper, the CIM is applied to the geosynchronous orbit and its performance and limitations will be investigated from the results. The CIM impliments two sensors (Sun and Earth sensors). The Sun sensor finds the angle between the spin-axis and the direction vector to the Sun and the Earth sensor does the angle between the spin-axis and the direction vector to the Earth. By using these two cone angles, the CIM gives the direction of the spin-axis of the satellite.

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Enhancement of Herboxidiene Production in Streptomyces chromofuscus ATCC 49982

  • Jha, Amit Kumar;Lamichhane, Janardan;Sohng, Jae Kyung
    • Journal of Microbiology and Biotechnology
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    • v.24 no.1
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    • pp.52-58
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    • 2014
  • Structurally, herboxidiene contains the tetrahydropyran acetic acid moiety and a side chain including a conjugated diene, and has been isolated from Streptomyces chromofuscus ATCC 49982. Its production was significantly elevated nearly 13.5-fold (0.74 g/l) in a medium supplemented with glycerol (medium No. 6A6), and was more efficacious (1.08 g/l; 19.8-fold) in fed-batch fermentation at 36 h in medium No. 6A6, from Streptomyces chromofuscus. For further enhancement, regulatory genes metK1-sp and afsR-sp from Streptomyces peucetius were overexpressed using an expression vector, pIBR25, and similarly ACCase from Streptomyces coelicolor and two genes, metK1-sp and afsR-sp, were also overexpressed using an integration vector, pSET152, under the control of the strong $ermE^*$ promoter in Streptomyces chromofuscus. Only the recombinant strains S. chromofuscus SIBR, S. chromofuscus GIBR, and S. chromofuscus AFS produced more herboxidiene than the parental strain in optimized medium No. 6A6 with an increment of 1.32-fold (0.976 g/l), 3.85-fold (2.849 g/l), and 1.7-fold(1.258 g/l) respectively.

TEMPORAL CHANGE OF MAGNETIC SHEAR FREE FROM THE 180° AMBIGUITY

  • MOON Y.-J.;WANG HAIMIN;SPIROCK THOMAS J.;PARK Y. D.
    • Journal of The Korean Astronomical Society
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    • v.35 no.3
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    • pp.143-149
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    • 2002
  • In this paper we present a methodology to derive the temporal change of the magnetic shear angle from a series of vector magnetograms, with a high time cadence. This method looks for the minimum change of the shear angle between a pair of magnetograms, free from the $180^{\circ}$ ambiguity, and then accumulates this change over many successive pairs to derive the temporal change of magnetic shear. This methodology will work well if only the successive magnetograms occurred in an active region are well aligned and its helicity sign is reasonably determined. We have applied this methodology to a set of vector magnetograms of NOAA Active Region 9661 on October 19, 2001 by the new digital magnetograph at the Big Bear Solar Observatory (BBSO). For this work we considered well aligned magnetograms whose cross-correlation values are larger than 0.95. As a result, we have confirmed the recent report of Wang et al. that there was the abrupt shear change associated with the X1.6 flare. It is also demonstrated that the shear change map can be an useful tool to highlight the local areas that experienced the abrupt shear change. Finally, we suggest that this observation should be a direct support of the emergence of sheared magnetic fields.

Analysis of 3-phase Induction Motor considering Current Regulator using DQ Transformation with Matrix Vector

  • Hong, Sun-Ki;Na, Yoo-Chung
    • Journal of international Conference on Electrical Machines and Systems
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    • v.3 no.2
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    • pp.116-120
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    • 2014
  • 3-phase Induction machines are being used in industry and dq transformation from 3 phase of a, b, c is commonly used to analyze these machines. The equivalent circuits of d and q axis are however generally cross coupled and not simple to analyze. In this study, an analysis method of 3ph induction motor considering current regulator using dq transformation and matrix vector is proposed and it can explain the 3ph induction motor physically. This model does not need the separating process of d and q components. With this technique, the model becomes simple, is easy to understand in physical, and can get the same results with those from the other dq models. These simulation results of the proposed model are compared with those of other models for the conformation of the proposed method.

A NOVEL FUZZY SEARCH ALGORITHM FOR BLOCK MOTION ESTIMATION

  • Chen, Pei-Yin;Jou, Jer-Min;Sun, Jian-Ming
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1998.06a
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    • pp.750-755
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    • 1998
  • Due to the temporal spatial correlation of the image sequence, the motion vector of a block is highly related to the motion vectors of its adjacent blocks in the same image frame. If we can obtain useful and enough information from the adjacent motion vectors, the total number of search points used to find the motion vector of the block may be reduced significantly. Using that idea, an efficient fuzzy prediction search (FPS) algorithm for block motion estimation is proposed in this paper. Based on the fuzzy inference process, the FPS can determine the motion vectors of image blocks quickly and correctly.

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Expression of heterologous genes using the slpA promoter and signal sequence in Lactobacilli

  • Gang, Seung-Ha;Bok, Jin-Deok;Jo, Gwang-Geun;Jo, Jae-Sun;Choe, Yun-Jae
    • 한국생물공학회:학술대회논문집
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    • 2000.11a
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    • pp.202-205
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    • 2000
  • A gene coding $endo-{\beta}$,-1, 4 glucanase from Actinomyces sp. KNG40 and phytase from Hansenula polymorpha were cloned into Esherichia coli JM101 by using E. coli/Lactobacillus shuttle vector pNZ3004 and pNZ123. The plasmid p3PS(1-4) and p123(1-4) have slpA promoter and slpA signal sequence. So, I constructed expression vectors, p3PS(1-4)Endo, phy and p123(1-4)Endo, phy. These constructed vector was transformed in target host Lactobacillus gasseri and reutri. These transformed host expressed endoglucanase and phytase as extracellular fraction. In the enzyme activity of the same vector, host L, gasseri was higher activity than L. reuteri. This indicates that L. gasseri recongnize promoter and signal sequence very well.

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Pattern Classification using Fuzzy Suppot Vector machine (퍼지 써포트 벡터 머신을 이용한 패턴 분류)

  • Lee, Sun-Young;Kim, Sung-Soo
    • Proceedings of the KIEE Conference
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    • 2004.07d
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    • pp.2540-2542
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    • 2004
  • 일반적으로 support vector machine (SVM)은 입력 데이터를 두개의 다른 클래스로 구별하는 결정면을 학습을 통하여 구한다. 특히 비분류 문제, 비선형 분류 문제들과 같은 두-클래스 문제를 해결하기 위해 데이터를 고차원의 특정 공간에서 다룬다. 많은 응용분야에서, 각 입력 데이터들은 이 두개의 클래스 중의 하나로 완전히 정의되지 않을 수도 있다. 이러한 문제를 해결하기 위해 우리는 본 논문에서 FSVM(fuzzy support vector machine)을 적용한다. 각 입력 데이터에 퍼지 멤버십(fuzzy membership)을 적용하여 결정면의 학습과정에 입력 데이터들이 다른 기여 (contribution)를 할 수 있게 한다. 본 논문에서는 기준 데이터 집합에 대해 제안된 방법을 실험하고, FSVM이 기존의 SVM보다 더 나음을 보인다.

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A Study on AC Machine Modeling using Complex Vector and dq Transformation (복소 벡터와 dq 변환을 이용한 교류기 모델링에 관한 연구)

  • Hong, Sun-Ki;Park, Jin-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.11
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    • pp.1601-1605
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    • 2012
  • Three-phase voltage and current is applied to the three-phase alternating current motors which are commonly used in industry. Three phase variables of a, b, c are converted into d, q, 0 axis and the AC machines are modeled and analyzed. Basically the coordinate transformation or d-q transformation is used for convenience, a few steps are needed to analyze the motor performances - separating d and q components, establishing each equivalent circuit, and solving the differential equations of the circuits. In this study, a modeling technique of induction motor using complex vector is proposed and it can explain the induction motor physically. This method does not need the separating process of d and q components. With this technique, the model becomes simple, is easy to understand in physical, and can get the same results with those from the other models. These simulation results of the proposed model are compared with them for the conformation of the proposed method.

Development of Speed Controller in Induction Machine using Vector Control Method (벡터제어방식에 의한 유도전동기 제어기 개발)

  • Lee, Sun-Hee;Kwon, Hyuk;Lee, Sang-Jeong;Joo, Hyeong-Gil;Hong, Sung-Il;Lee, Seung-Hak
    • Proceedings of the KIEE Conference
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    • 1998.07f
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    • pp.1990-1992
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    • 1998
  • A vector control scheme is widely used in AC drive system in these days. In this country for commercializing the system, it has lots of dependency on advanced foreign technology. Therefore we have developed high-performance vector controlled inverter sytems ourselves for two years whose capacitives are 15kW, 30kW and 45kW. For computation of data in high speed DSP is empolyed and by using a IGBT with high switching the current ripple is reduced. Consequently, developed drive systems have high performance and accurary on speed control. There are proved in experimental results.

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