• Title/Summary/Keyword: Cross-Coupling

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New Design and Synthesis of Donor-Acceptor units by Introducing Boron Based to Non-Boron based Semiconductor for high Voc OPV

  • Ryu, Ka Yeon;Cho, Kyuwan;Kim, Won-Suk;Kim, Kyungkon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.432.2-432.2
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    • 2016
  • A new A-D-A type (Acceptor-Donor-Acceptor) conjugated based on pyridine-borane complex (Donor), non-boron fluorine (Donor) and 2,5-bis(alkyl)-3,6-di(thiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione (DPP) (Acceptor) were designed and synthesized via Pd-catalyzed Suzuki cross-coupling reaction. The synthesized boron based complex exhibited high electron affinity, which indicates deep HOMO energy levels and good visible absorption led to their use as donors in BHJ (bulk heterojunction) solar cells. Inverted devices were fabricated, reaching open-circuit voltage as high as 0.91eV. To probe structure-property relationship and search for design principle, we have synthesized pyridine-boron based electron donating small molecules. In this study, we report a new synthetic approach, molecular structure, charge carrier mobility and morphology of blended film and their correlation with the photovoltaic J-V characteristics in details.

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Experimental Determinations of Coherent Multidimensional Vibrational Spectroscopy

  • Besemann, Daniel;Condon, Nicholas;Meyer, Kent;Zhao, Wei;Wright, John C.
    • Bulletin of the Korean Chemical Society
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    • v.24 no.8
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    • pp.1119-1125
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    • 2003
  • Coherent multidimensional vibrational spectroscopy is a new technique for establishing correlations between features in vibrational spectra that are caused by intra- and intermolecular interactions. These interactions cause cross-peaks between vibrational transitions that reflect the coupling. In this paper, we use Doubly Vibrationally Enhanced Infrared Spectroscopy (DOVE-IR) and DOVE-Raman processes to obtain coherent two dimensional vibrational spectra. The spectra are fitted to obtain the dephasing rates and third order susceptibilities $(χ^{(3)})$ for the nonlinear processes. We show that the DOVE $χ^{(3)}$ values are directly related to the molar absorptivities and Raman $χ^{(3)}$. We then use these relationships to obtain estimates for the $χ^{(3)}$ of the stimulated photon echo and $χ^{(5)}$ of the six wave mixing spectroscopies, respectively. We also predict the ratio of the cascaded four wave mixing signal to the six wave mixing signal.

A Novel Utilization Method of the Predicted Current in the High Performance PI Current Controller with a Control time delay (제어 시지연이 있는 고성능 PI 전류제어기에 대한 예측전류의 적용방법)

  • Lee, Jin-Woo
    • The Transactions of the Korean Institute of Power Electronics
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    • v.11 no.5
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    • pp.426-430
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    • 2006
  • This paper deals with a novel utilization method of the predicted current in the high performance PI current controller with a control time delay. The inevitable error of the predicted current in the linear servo drive using a permanent magnet linear synchronous motor is analyzed and a modified cross-coupling decoupling synchronous frame PI current controller is proposed in order to improve the current control response under both the control time delay and the inevitable current prediction error. Simulation and experimental results show that the proposed current controller has an improved current control performance under both the control time delay and the inevitable current prediction error in the servo drive system.

Modification of effective index method for a fast and accurate beam propagating computational analysis of optical waveguide devices in 3-dimensional struture (3차원 구조 광도파로소자의 신속 정확한 광속전파 전산해석을 위한 유효굴절법의 수정)

  • 김한수
    • Korean Journal of Optics and Photonics
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    • v.10 no.1
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    • pp.40-46
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    • 1999
  • We present a new modified effective index method which can be used to analyze lightwave circuit devices in 3-dimensional structure fast and accruatly using 2-dimensional BPM (beam propagating method). This method can analyze the devices with the cross-section of rectangular, ridge, or similar shapes accurately but more quickly than the 3-dimensional BPM, which is impractical to use on account of long calculating time. As an example, we showed that the calculation error of coupling length in a directional coupler by this method is significantly less than the 2-dimensional BPM using the effective index method.

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Flight Dynamic Identification of a Model Helicopter using CIFER®(II) - Frequency Response Analysis - (CIFER®를 이용한 무인 헬리콥터의 동특성 분석 (II) - 주파수 응답 해석 -)

  • Bae, Yeoung-Hwan;Koo, Young-Mo
    • Journal of Biosystems Engineering
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    • v.36 no.6
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    • pp.476-483
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    • 2011
  • The aerial application using an unmanned helicopter has been already utilized and an attitude controller would be developed to enhance the operational convenience and safety of the operator. For a preliminary study of designing flight controller, a state space model for an RC helicopter would be identified. Frequency sweep flight tests were performed and time history data were acquired in the previous study. In this study, frequency response of the flight test data of a small unmanned helicopter was analyzed by using the CIFER software. The time history flight data consisted of three replications each for collective pitch, aileron, elevator and rudder sweep inputs. A total of 36 frequency responses were obtained for the four control stick inputs and nine outputs including linear velocities and accelerations and angular velocities in 3-axis. The results showed coherence values higher than 0.6 for every primary control inputs and corresponding on-axis outputs for the frequency range from 0.07 to 4 Hz. Also the analysis of conditioned frequency response showed its effectiveness in evaluating cross coupling effects. Based on the results, the dynamic characteristics of the model helicopter can further be analyzed in terms of transfer functions and the undamped natural frequency and damping ratio of each critical mode.

Thermal Stability Analysis of a Flexible Beam Spacecraft Appendage (위성체 유연 보 구조물의 열 안정성 해석)

  • 윤일성;송오섭
    • Composites Research
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    • v.15 no.3
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    • pp.18-29
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    • 2002
  • The bending vibration and thermal flutter instability of spacecraft booms modeled as circular thin-walled beams of closed cross-section and subjected to thermal radiation loading is investigated in this paper. The thin-walled beam model incorporates a number of nonclassical effects of transverse shear, primary and secondary warping, rotary inertia and anisotropy of constituent materials. Thermally induced vibration response characteristics of a composite thin walled beam exhibiting the circumferantially uniform system(CUS) configuration are exploited in connection with the structural flapwise bending-lagwise bending coupling resulting from directional properties of fiber reinforced composite materials and from ply stacking sequence. The numerical simulations display deflection time-history as a function of the ply-angle of fibers of the composite materials, damping factor, incident angle of solar heat flux, as well as the boundary of the thermal flutter instability domain. The adaptive control are provided by a system of piezoelectric devices whose sensing and actuating functions are combined and that are bonded or embedded into the host structure.

Control of Heavy Duty Robot using Robust Proportional Integral Sliding Mode (강인한 비례적분 슬라이딩 모드를 이용한 초중량물 로봇의 제어)

  • Ko, Chang-Min;Park, Seong-Hun;Lee, Hyun-Seok;Kim, Min-Chan;Park, Seung-Kyu;Kim, Doo-Hyeong;Chung, Gwang-Jo
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.1729_1730
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    • 2009
  • This paper presents comparative experimental results of PI sliding mode control and PI control for a heavy duty robot which can handle an object of 600kg, The gains of the PI control was determined by TAE(Trial and Error) method. This paper presents a novel approach for the decoupling of the states cross-coupling using sliding mode control. The sliding mode control methode is based on the error between reference speeds and the actual speed. The proposed method has the advantages of PI control performance and the sliding mode control robustness. Its first step is to design PI controller, then the sliding mode control input term is added to it. This makes actual implementation of the controller easier. The robot and motion controllers were designed and made by author. The good control performance of the heavy duty robot was obtained by using simple algorithm. This means that the robot was designed very well in control respect.

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Analysis of Reinforced Concrete Slab Bridges by the Composite Laminates Theory (복합적층판 이론에 의한 철근콘크리트 슬래브교의 해석)

  • Han, Bong-Koo;Kim, Duck-Hyun
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.1 no.1
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    • pp.9-15
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    • 2010
  • In this paper, A reinforced concrete slab bridges is analyzed by the composite laminates theory. Both the geometry and the material of the cross section of the reinforced concrete slab bridge are considered symmetrical with respect to the mid-surface so that the bending extension coupling stiffness, Bij = 0, and D16 = D26 = 0. Each longitudinal and transverse steel layer is regarded as a lamina, and material constants of each lamina is calculated by the use of rule of mixture. This slab with simple support is under uniformly distributed vertical and axial loads. In this paper, the finite difference method and specially orthotropic laminates theory are used for analysis. The result of specially orthotropic laminates theory analysis is modified to obtain the solution of the beam analysis. The result of this paper can be used for reinforced concrete slab analysis by the engineers with undergraduate study in near future.

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A Study on the East-West Station Keeping Box of Koreasat 2 (무궁화위성 2호의 동서위치유지 박스 설정에 관한 연구)

  • Lee,Sang-Cheol;Kim,Bang-Yeop;Park,Bong-Gyu
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.9
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    • pp.75-81
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    • 2003
  • The longitude and latitude of a geosynchronous satellite are not defined as a point in space because of various external perturbations. To perform the missions of a satellite for a communication and broadcasting, the satellite must be positioned within a predefined station keeping box in given limited space longitude. In this study, we propose east-west station keeping box larger than that of north-south station. By using the derived error equation, we verified the Koreasat station keeping box allocation by assuming one week and two weeks of station keeping cycle.

Control of Electrically Excited Synchronous Motors with a Low Switching Frequency

  • Yuan, Qing-Qing;Wu, Xiao-Jie;Dai, Peng;Fu, Xiao
    • Journal of Power Electronics
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    • v.12 no.4
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    • pp.615-622
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    • 2012
  • The switching frequency of the power electronic devices used in large synchronous motor drives is usually kept low (less than 1 kHz) to reduce the switching losses and to improve the converter power capability. However, this results in a couple of problems, e.g. an increase in the harmonic components of the stator current, and an undesired cross-coupling between the magnetization current component ($i_m$) and the torque component ($i_t$). In this paper, a novel complex matrix model of electrically excited synchronous motors (EESM) was established with a new control scheme for coping with the low switching frequency issues. First, a hybrid observer was proposed to identify the instantaneous fundamental component of the stator current, which results in an obvious reduction of both the total harmonic distortion (THD) and the low order harmonics. Then, a novel complex current controller was designed to realize the decoupling between $i_m$ and $i_t$. Simulation and experimental results verify the effectiveness of this novel control system for EESM drives.