• Title/Summary/Keyword: Symmetrical structure

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An Efficient Hardware Architecture of Coordinate Transformation for Panorama Unrolling of Catadioptric Omnidirectional Images

  • Lee, Seung-Ho
    • Journal of IKEEE
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    • v.15 no.1
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    • pp.10-14
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    • 2011
  • In this paper, we present an efficient hardware architecture of unrolling image mapper of catadioptric omnidirectional imaging systems. The catadioptric omnidirectional imaging systems generate images of 360 degrees of view and need to be transformed into panorama images in rectangular coordinate. In most application, it has to perform the panorama unrolling in real-time and at low-cost, especially for high-resolution images. The proposed hardware architecture adopts a software/hardware cooperative structure and employs several optimization schemes using look-up-table(LUT) of coordinate conversion. To avoid the on-line division operation caused by the coordinate transformation algorithm, the proposed architecture has the LUT which has pre-computed division factors. And then, the amount of memory used by the LUT is reduced to 1/4 by using symmetrical characteristic compared with the conventional architecture. Experimental results show that the proposed hardware architecture achieves an effective real-time performance and lower implementation cost, and it can be applied to other kinds of catadioptric omnidirectional imaging systems.

A Macrocyclization of (2R)-2-(N,N-Ditosylimido) -3-butenyl methyl malonate by Using Palladium Catalyst (팔라듐 촉매를 이용한 (2R)-2-(N,N-Ditosylimido)-3-butenyl methyl malonate의 거대고리화 반응)

  • Kim, Gyu-Soon;Rhee, Hak-June
    • Journal of the Korean Chemical Society
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    • v.44 no.1
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    • pp.30-36
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    • 2000
  • Upon Pd(0)-catalyzed coupling reaction of (2R)-2-(N,N-ditosylimido)-3-butenyl methyl malonate (4) which was selected for the total synthesis of A-factor, (3R)-2-(6-methylheptanoyl)-3-hydroxy methyl-4-buttinolide (1), an unexpected 14-membered cyclic compound, bis(2-methoxycabonyl-(4E)-hexenolide) (15) was obtained. The structure of this compound was conformed by X-ray crystallography. This result implies that this method can be applied the synthesis of various size of symmetrical macrocyclic compounds.

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Design of wide Band Microwave Amplifier with Good Frequncy Characteristics (주파수 특성이 좋은 광대역 마이크로웨이브 증폭기의 설계)

  • Kang, Hee-Chang;park, Il;Chin, Youn-kang
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.2 no.2
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    • pp.3-10
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    • 1991
  • The new structure method of GaAs microwave amplifiers using DC block function and impedance transforming property of DC block/transformer(non-symmetrical two - microstrip coupled line and interdigital three - microstrip coupled line), instead of chip capacitor, is presented. The newly structured microwave amplifier showed wideband characteristics(bandwidth, 3.5 GHz) and flat frequency response. Interdigital three - microstrip coupled line which is used for microwave amplifier can be used to match amplifiers as well as DC blocking.

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Characteristics of the Haute Couture Design in Paris and Rome (파리와 로마의 오뜨 꾸띄르(Haute Couture) 디자인의 특성)

  • 공미선
    • Journal of the Korean Society of Costume
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    • v.39
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    • pp.39-58
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    • 1998
  • In this research, first of all, the special feat-ures of Haute Couture design world (1990∼1996) prevailed in Paris and Rome are investigated, and additionally the understanding of collection concept and design structure analysis are performed to show the various method-ology of creative design. Expression method and design method are the main criteria in analyzing, and the main results of this research are summarized as follows : 1. Most of designers in Paris and Rome ex-press the traditional costume style. Paris designers are focusing on the expression of design morphology through the abstraction and re-appearance without being confined to theme expression ; Rome designers are expressing their main ideas utilizing the fashion image as their theme in lieu of expressing the design morphology. 2. Most of the designers in Paris and Rome are using simple lines for their design. Paris designers prefer the plastic design based upon formal and symmetrical balance of informal and asymmetrical balance to the partial trans-formation design ; Rome designers are enjoy-ing rather the partial transformation using the detail and trimming than the plastic design.

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Vibration Control Characteristics of Laminated Composite ER Beams with Electric Field Dependence (전기장에 따른 복합재 ER Beam의 진동제어 특성)

  • 김재환;강영규;최승복
    • Journal of KSNVE
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    • v.11 no.3
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    • pp.416-421
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    • 2001
  • The flexural vibration of laminated composite beams with an electro-rheological(ER) fluid has been investigated to design a structure with maximum possible damping capacity. The equations of motion are derived for flexural vibrations of symmetrical, mu1ti-layer laminated beams. The damping radio and modal damping of the first bending mode are calculated by means of iterative complex eigensolution method. Finite element method is used for the analysis of dynamic characteristics of the laminated composite beams with an ER fluid. For the validation of modeling methodology using viscoelastic theory the predicted dynamic properties are compared to the measured ones by author's previous work. They are in good agreement. This paper addresses a design strategy of laminated composite under flexural vibrations with an ER fluid.

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Analysis of Doping Profile Dependent Threshold Voltage for DGMOSFET Using Gaussian Function

  • Jung, Hak-Kee
    • Journal of information and communication convergence engineering
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    • v.9 no.3
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    • pp.310-314
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    • 2011
  • This paper has presented doping profile dependent threshold voltage for DGMOSFET using analytical transport model based on Gaussian function. Two dimensional analytical transport model has been derived from Poisson's equation for symmetrical Double Gate MOSFETs(DGMOSFETs). Threshold voltage roll-off is very important short channel effects(SCEs) for nano structures since it determines turn on/off of MOSFETs. Threshold voltage has to be constant with decrease of channel length, but it shows roll-off due to SCEs. This analytical transport model is used to obtain the dependence of threshold voltage on channel doping profile for DGMOSFET profiles. Also we have analyzed threshold voltage for structure of channel such as channel length and gate oxide thickness.

Vibration Control of Laminated Composite Beams Using Active Constrained Layer Damping Treatment (능동구속감쇠 기법을 이용한 복합적층보의 진동 제어)

  • 강영규;최승복
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.11 no.7
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    • pp.261-266
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    • 2001
  • The flexural vibration of laminated composite beams with active and passive constrained layer damping has been investigated to design a structure with maximum possible damping capacity. The equations of motion are derived fro flexural vibrations of symmetrical,. multi-layer laminated beams. The damping ratio and model damping of the first bending mode are calculated by means of iterative complex eigensolution method. The direct negative velocity feedback control is used for the active constrained layer damping. It is shown that the flexible laminated beam is more effective in the vibration control for both active and passive constrained layer damping. and this paper addresses a design strategy of laminated composite under flexural vibrations with constrained layer damping.

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Placement of passive Constrained Layer Damping for Vibration Control of Smart Plate (지능판의 진동제어를 위한 수동구속감쇠의 위치 설정)

  • Kang, Yong-Kyu;Kim, Chan-Mook
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11b
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    • pp.12-16
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    • 2002
  • Dynamic characteristics of smart laminated composite plates with passive constrained layer damping have been investigated to design structure with maximum possible damping capacity. The equations of motion are derived for flexural vibrations of symmetrical, multi-layer laminated plates. The damping ratio and modal damping of the first bending and torsional modes are calculated by means of iterative complex eigensolution method. The structural damping index(SDI) is introduced to determine the optimum placement of viscoelastic patch. This paper addresses a design strategy of laminated composite plate under vibrations.

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A 3.3V-65MHz 12BIT CMOS current-mode digital to analog converter (3.3V-65MHz 12비트 CMOS 전류구동 D/A 변환기 설계)

  • 류기홍;윤광섭
    • Proceedings of the IEEK Conference
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    • 1998.06a
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    • pp.518-521
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    • 1998
  • This paper describes a 3.3V-65MHz 12BIT CMOS current-mode DAC designed with a 8 MSB current matirx stage and a 4 LSB binary weighting stage. The linearity errors caused by a voltage drop of the ground line and a threshold voltage mismatch of transistors have been reduced by the symmetrical routing method with ground line and the tree structure bias circuit, respectively. In order to realize a low glitch energy, a cascode current switch ahs been employed. The simulation results of the designed DAC show a coversion rate of 65MHz, a powr dissipation of 71.7mW, a DNL of .+-.0.2LSB and an INL of .+-.0.8LSB with a single powr supply of 3.3V for a CMOS 0.6.mu.m n-well technology.

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Analysis and tests of flexibly connected thin-walled channel frames

  • Tan, S.H.;Seah, L.K.
    • Structural Engineering and Mechanics
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    • v.2 no.3
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    • pp.269-284
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    • 1994
  • The analysis and tests of thin-walled channel frames including nonlinear flexible or semi-rigid connection behaviour is presented. The semi-rigid connection behaviour is modelled using a mathematical approximation of the connection flexibility-moment relationship. Local instability such as local buckling and torsional flexural buckling of the member are included in the analysis. The full response of the frame, up to the collapse load, can be predicted. Experimental investigation was carried out on a series of simple double storey symmetrical frames with the purpose of verifying the accuracy and validity of the analysis. Agreement between the theoretical and experimental results is acceptable. The investigation also shows that connection flexibility and local instability such as local buckling and torsional flexural buckling can affect the behaviour and strength of thin-walled frames significantly. The results can also provide further insight into the advanced study of practical structures where interaction between flexible connections and phenomenon associated with thin-walled members are present.