• Title/Summary/Keyword: SOF

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Design of $H_2$ and $H_{\infty}$ static output feedback controllers (정적출력궤환 $H_2$$H_{\infty}$ 제어기 설계)

  • Kim, Seog-Joo;Lee, Jong-Moo;Cheon, Jong-Min;Kwon, Soon-Man;Park, Min-Kook
    • Proceedings of the KIEE Conference
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    • 2005.07d
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    • pp.2564-2566
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    • 2005
  • This paper presents an iterative linear matrix inequality (LMI) method for $H_2$ and $H_{\infty}$ optimal static output feedback (SOF) control, which is expressed in terms of LMIs subject to an additional rank condition. We propose a linear Penalty function to penalize the rank constraint so that static $H_2$ and $H_{\infty}$ synthesis results in solving a series of convex LMI optimization problems. Numerical experiments for various $H_2$ and $H_{\infty}$ SOF synthesis were performed to demonstrate the effectiveness of the proposed algorithm.

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Comparison Among Yaw and Roll Motion Controllers for Rollover Prevention (차량 전복 방지를 위한 롤 및 요 운동 제어기의 성능 비교)

  • Yim, Seongjin
    • Journal of Institute of Control, Robotics and Systems
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    • v.20 no.7
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    • pp.701-705
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    • 2014
  • This article presents a comparison among several yaw and roll motion controllers for vehicle rollover prevention. In the previous research, yaw and roll motion controllers can be independently designed for rollover prevention. Following this idea, several yaw and roll motion controllers are designed and compared in terms of rollover prevention. For the yaw motion control, PID, LQR, SMC (Sliding Mode Control) and TDC (Time-Delay Control) are adopted. For the roll motion control, LQR, LQ SOF (Static Output Feedback) control, PID, and SMC are adopted. To compare the performance of each controller, simulation is performed on a vehicle simulation package, CarSim$^{(R)}$. From simulation, TDC and LQ SOF are the best for yaw and roll motion control, respectively.

연마법이 치과용 복합레진의 표면 조도에 미치는 영향에 관한 실험적 연구

  • Yang, Hong-So
    • The Journal of the Korean dental association
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    • v.24 no.7 s.206
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    • pp.633-642
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    • 1986
  • In order to evaluate the effects of various finishing devices (Sof-Lex disc, diamond point, rubber point, fussure bur) on the surface roughness or two composite resins (Restodent, Enamelite 500), 15 specimens for each composite resin were made in the mold. Composite resin was prepared on the mixing pad by manufacturer's direction and filled in the mold cavity. A sheet of matrix is immediately placed on it and hold for 5 minutes to polymerize the resin. Surface finish was done after 10 minutes from the start of mixing. Scanning electron microscopy and surface profilometer were used to evaluate the surface roughness, porositites and striations of dental composite resins. The following results were observed; 1. The best finished surface was formed by celluloid matrix band. 2. Rubber point was excellent polishing device for Restodent. 3. Sof-Lex disc was the device of choice for polishing Enamelite 500. 4. Different polishing methods were effective for different composite resins. 5. SEMs of variously finished surfaces supported the profilometer measurements.

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A STUDY ON THE ROUGHNESS OF THE RESTORATIVE COMPOSITE RESIN (수복용(修複用) 복합(復合)레진의 표면조도(表面粗度)에 관(關)한 연구(硏究))

  • Lee, Myung-Jong
    • Restorative Dentistry and Endodontics
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    • v.13 no.2
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    • pp.207-220
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    • 1988
  • The purpose of this study was to measure roughness on the polished surfaces of composite resin, and was to observe the polished surfaces under Scanning Electron Microscope. The surface roughness tester (Surfcom 700A Semitsu Profilometer Tokyo. Japan) was used to measure roughness of polished surfaces. In this study, 4 brands of composite resin were examined, Pyrofil bond anterior Bell-Feel anterior Clearfil F II and Microrest A.P. White point, Silicone point, Super snap, and Sof-Lex medium disc as cutting instrument, and celluloid matrix were used. The results obtained were as follows. 1) The celluloid matrix produced the smoothest surfaces. 2) Microrest composite resin had smoother surface than any other composite resins after polishing. 3) The values of surface roughness made by White point, Silicon point and Super snap were similar. 4) The surfaces made by Sof-Lex medium disc was smoother than the surfaces made by any other polishing instruments.

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유압 위치제어 시스템의 단속적 제어방법에 관한 연구 I

  • 장효환;안병홍;이춘호
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.11 no.3
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    • pp.465-472
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    • 1987
  • Two kinds of discontinuous control methods i, e., simple on-off(SOF) control and pulsating on-off(POF) control methods are implemented and compared each other for a low cast hydraulic position-control system which utilizes a solenoid-operated directional valve instead of a servovalve. Experimental work was carried out to investigate effects of control parameters and loading conditions on step response characteristics of the system for each control method. The results show that much higher accuracy and much better transient response characteristics can be achieved by POF controller than those by SOF controller. The results may be used as basic data in the selection of control parameters as well as in the design of the hydraulic position-control system.

Comparison of Culture Media for In Vitro Maturation of Oocytes of Indigenous Zebu Cows in Bangladesh

  • Singha, Joydev Kumar;Bhuiyan, Mohammad Musharraf Uddin;Rahman, Mohammad Moshiur;Bari, Farida Yeasmin
    • Journal of Embryo Transfer
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    • v.30 no.4
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    • pp.327-333
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    • 2015
  • The objectives of the present study were to select an effective basic medium including its hormone and protein supplementation for IVM of oocytes of indigenous zebu cows. The ovaries of cows were collected from slaughter house and the follicular fluid was aspirated from 2 to 8 mm diameter follicles. The COCs with more than 3 cumulus cell layers and homogenous cytoplasm were selected for maturation. The oocytes were matured in media for 24 hrs at $39^{\circ}C$ with 5% $CO_2$ in humidified air. The maturation of oocytes was evaluated by examining the presence of first polar body under microscope. An efficient basic medium was determined after culturing COCs in either TCM 199 or SOF medium in Experiment 1. An efficient hormone supplementation was determined after culturing COCs in either FSH or gonadotrophin supplemented TCM 199 in Experiment 2. An efficient protein supplementation was determined after culturing COCs in either FBS or Oestrous cow serum (OCS) supplemented TCM 199 in Experiment 3. The oocyte recovery rate per ovary was 3.35. The overall rate of IVM was 74.6%. The maturation rate was $75.5{\pm}3.9$ and $62.2{\pm}20.2%$ in TCM and SOF medium, respectively (P>0.05). The maturation rate of oocytes was significantly higher ($76.6{\pm}13.2%$) in FSH supplemented medium than gonadotrphin supplemented counterpart ($69.7{\pm}10.8%$) (P<0.05). The maturation rates of oocytes were $81.7{\pm}12.9$ and $85.7{\pm}12.7%$ in medium supplemented with FBS and OCS, respectively (P>0.05). In conclusions, both TCM 199 and SOF supplemented with either FBS or OCS, and FSH may be used as medium for IVM of indigenous zebu oocytes in Bangladesh.

Experimence Study of Trace Water and Oxygen Impact on SF6 Decomposition Characteristics Under Partial Discharge

  • Zeng, Fuping;Tang, Ju;Xie, Yanbin;Zhou, Qian;Zhang, Chaohai
    • Journal of Electrical Engineering and Technology
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    • v.10 no.4
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    • pp.1786-1795
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    • 2015
  • It is common practice to identify the insulation faults of GIS through monitor the contents of SF6 decomposed components. Partial discharges (PD) could lead to the decomposition of SF6 dielectric, so new reactions usually occur in the mixture of the newly decomposed components including traces of H2O and O2. The new reactions also cause the decomposed components to differ due to the different amounts of H2O and O2 even under the same strength of PD. Thus, the accuracy of assessing the insulation faults is definitely influenced when using the concentration and corresponding change of decomposed components. In the present research, a needle-plate electrode was employed to simulate the PD event of a metal protrusion insulation fault for two main characteristic components SO2F2 and SOF2, and to carry out influence analysis of trace H2O and O2 on the characteristic components. The research shows that trace H2O has the capability of catching an F atom, which inhibits low-sulfide SFx from recombining into high-sulfide SF6. Thus, the amount of SOF2 strongly correlates to the amount of trace H2O, whereas the amount of SO2F2 is weakly related to trace H2O. Furthermore, the dilution effect of trace O2 on SOF2 obviously exceeds that of SO2F2.

A Comparative Study on Louis L Kahn's Architectural Philosophy and Kabbalah based on Psychoanalysis (정신분석학에 의한 루이스 칸의 건축철학과 카발라와의 비교 연구)

  • Choi, Hyo-Sik
    • Journal of architectural history
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    • v.18 no.2
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    • pp.85-105
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    • 2009
  • This study set out to compare and analyze the influences Kabbalah, which was Louis I. Kahn's faith as a Jew, on his architecture based on Freud's psychoanalysis that had many exchanges with modernism and contemporary architecture and theories. The specific goals of the study were to shed light to Kahn's presence in contemporary architecture anew and establish the methodology of using psychoanalysis in building new theories of architectural planning. When the theories of psychoanalysis were introduced for comparison and analysis purposes, Kahn tried to differentiate his buildings by placing a function or symbolic central space at the heart of a building even though he did adopt a characteristic of modernism architecture, which was placing a core at the centre of plan, for a while. Such a tendency of his was based on Jung's opinions rather than Freud's and affected by Ecole des Beaux-Art. The analysis results also indicate that he conceived "Served Space & Servant Space," "architecture of connection" and "silence and light" that made up the essence of his architectural theory from the relationships between Ayin-Sof, Kabbalah's absolute god, and Sefiroth. It's also very likely that his often use of triangles and circles in his architecture was affected by the Tree of Sefiroth diagram of Kabbalah. His tendency is well reflected in Salk Institute and Philips Exeter Academy Library, where he placed a laboratory or courtyard at the center where a core was supposed to be, created a corridor or courtyard space between those central spaces and the core, and connected them one another with to perceive the being of Ayin-Sof into an architectural space, which is well proven with Mikveh Israel Synagogue where he directly applied the Tree of Sefiroth diagram. The synagogue also contained a hollow column that served as an important concept in his late architecture. The hollow column was also the result of him applying the concept of Sefiroth of the place where Ayin-Sof Was reduced in Kabbalah.

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A SCANNING ELECTRON MICROSCOPIC STUDY ON CHANGES OF ENAMEL SURFACE BY INTERPROXIMAL STRIPPING AND POLISHING (치아인접면 삭제 및 연마에 따른 법랑질 표면의 변화에 관한 주사전자현미경적 연구)

  • Kim, Young-Sun;Kim, Kwang-Won
    • The korean journal of orthodontics
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    • v.22 no.1
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    • pp.123-131
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    • 1992
  • This study was done to evaluate the changes of enamel surface by interproximal stripping and recovery of it by polishing. The number of 34 1st premolars which had extracted for orthodontic treatment were selected as samples. Interproximal stripping was performed by hand with metal strip and strip placer (Dentaurum Co., Germany) and low speed handpiece with diamond disk (Superdiaflex, Germany). Polishing was performed by hand with plastic strip (3M Col) and low speed handpiece with whip-mix, DCPA (Dicalcium Phosphate, Anhydrous, $CaHPO_4$) powder and Sof-lex (3M Co. U.S.A.) polishing kit. Each groups were examined under the scanning electron microscope (JEOL Co., JSM-840A, Japan) and the following results were obtained: 1. The stripped group performed by metal strip and diamond disk altogether showed deep furrow on the enamel surface as wide as about $10{{\mu}m}$. 2. There could be seen more irregular scratched line in the group stripped by metal strip than that by diamond disk. 3. The polished group performed by plastic strip and DCPA powder showed slight smoothening of the edge of stripped furrow on the enamel surface without relation to the stripping method. 4. The polished group performed by Sof-lex progressive polishing kit could not avoid the formation of the furrows on the enamel surface according to the particle size without relation to the stripping method. 5. The polished group performed by the superfine polishing wheel, the final stage of Sof-lex polishing method showed shallow scratched line as wide as within about $2{{\mu}m}$ on the enamel surface without relation to the stripping method. 6. The interproximal stripped enamel surface could not recover its original surface texture by any kind of polishing methods.

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