• 제목/요약/키워드: $\pi$Configuration

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N-메틸루티돈의 電子構造와 光化學反應性에 關한 硏究 (Electronic Structure and Photoreactivity of N-Methyllutione)

  • 심상철;현명호;채규호
    • 대한화학회지
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    • 제21권6호
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    • pp.434-439
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    • 1977
  • 4-피리돈과 루티돈의 전자구조를 SCF MO-CI PPP 방법과 configuration analysis 법을 사용하여 연구하였다. 계산결과와 스펙트럼 분석치와는 잘 일치하였으며 첫번째 $({\pi},{\pi}^*)$ 단일상태는 두 화합물 모두 장축 방향으로 편극되어 있다. Configuration analysis 결과 가장 낮은 $({\pi},{\pi}^*)$ 단일 상태에서는 C=O 작용기의 ${\pi}$ 결합궤도로 부터 디비닐아민 부분의 ${\pi}^*$ 반결합 궤도로 전하가 이동되어 있으나 가장 낮은 $({\pi},{\pi}^*)$ 삼중상태에서는 반대로 디비닐아민 부분으로 부터 C=O 작용기 쪽으로 전하가 이동되어 있음을 알 수 있다.

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MYLLER CONFIGURATIONS IN FINSLER SPACES. APPLICATIONS TO THE STUDY OF SUBSPACES AND OF TORSE FORMING VECTOR FIELDS

  • Constantinescu, Oana
    • 대한수학회지
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    • 제45권5호
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    • pp.1443-1482
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    • 2008
  • In this paper we define a Myller configuration in a Finsler space and use some special configurations to obtain results about Finsler subspaces. Let $F^{n}$ = (M,F) be a Finsler space, with M a real, differentiable manifold of dimension n. Using the pull back bundle $({\pi}^{*}TM,\tilde{\pi},\widetilde{TM})$ of the tangent bundle $(TM,{\pi},M)$ by the mapping $\tilde{\pi}={\pi}/TM$ and the Cartan Finsler connection of a Finsler space, we obtain an orthonormal frame of sections of ${\pi}^{*}TM$ along a regular curve in $\widetilde{TM}$ and a system of invariants, geometrically associated to the Myller configuration. The fundamental equations are written in a very simple form and we prove a fundamental theorem. Important lines in a Finsler subspace are defined like special lines in a Myller configuration, geometrically associated to the subspace: auto parallels, lines of curvature, asymptotes. Torse forming vector fields with respect to the Cartan Finsler connection are characterized by means of the invariants of the Frenet frame of a versor field along a curve, and the new notion of torse forming vector fields in the sense of Myller is introduced. The particular cases of concurrence and parallelism in the sense of Myller are completely studied, for vector fields from the distribution $T^m$ of the Myller configuration and also from the normal distribution $T^p$.

Conjugated Oxime의 立體構造에 關한 硏究 (第2報). NMR에 依한 cis-2-Butenedialdioxime의 Configuration 및 水素結合에 對한 考察 (Structural Studies on Conjugated Oximes (II). Nuclear Magnetic Resonance spectral Analysis on the Configuration and Hydrogen Bond of cis-2-Butenedialdioxime in Solutions)

  • 홍영석;이학기
    • 대한화학회지
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    • 제19권4호
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    • pp.233-239
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    • 1975
  • 세개의 二重結合에 衣하여 conjugate된 비대칭화합물 cis-2-bitenedialdioxime의 두 oxime group의 configuration을 溶媒, 溫度 및 濃度의 影響에 대한 NMR 硏究로서 決定하였다. 溶液狀態에서의 이 化合物은 $-35^{circ}$$-95^{\circ}C$의 溫度條件下에서는 항상 "syn-syn" configuration으로 存在함을 알았다. 또한 이 化合物의 oxime group과 溶媒사이의 水素結合의 相對的强度와 溫度 및 濃度에 의 피리딘의 考察하고 몇가지 水素結合의 모델을 提示하였다. 特히 피리딘溶媒 속에서는 水素結合은 한 영향을 窒素가 갖고 있는 非共有電子雙에 衣해서 일어나지 않고, oxime 의 hydroxyl proton과 피리딘의 $\pi$軌道函數 사이에 形成되는 $\pi$-착물의 結果임을 알았다.

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Polarization Scattering Property of Cascaded Polarization Controllers

  • Muga, Nelson J.;Ferreira, Mario F.;Pinto, Armando Nolasco
    • ETRI Journal
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    • 제29권6호
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    • pp.838-840
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    • 2007
  • The relation between the allowed range of variation of polarization controller wave-plates angles and the respective polarization scattering properties is investigated. It is demonstrated that a nearly uniform polarization scattering over the Poincare sphere is obtained using a concatenation of three polarization controllers with angles randomly changed between $-{\pi}$/4 and ${\pi}$/4. It is also shown that an improvement of the scattering properties is obtained if the configuration angles are allowed to change between $-{\pi}$/2 and ${\pi}$/2.

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PI 제어기를 이용한 센서리스 속도제어 방식의 SRM 모델링 및 시뮬레이션 (SRM modeling and simulation of senserless speed control method using PI controller)

  • 최재동
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2000년도 전력전자학술대회 논문집
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    • pp.525-528
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    • 2000
  • This paper presents a circuit analysis and cotnrol example of favored configuration 6/4 SRM. SRM modeling and analysis are necessary for experiment. Thus this paper proposes a SRM modeling with PI controller (of driving converter) input voltage chopping and inductance profile when rotor position transformed. Through this simulation the designer can predict operating states of systems over a broad range of operating conditions.

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A Systematic Engineering Approach to Design the Controller of the Advanced Power Reactor 1400 Feedwater Control System using a Genetic Algorithm

  • Tran, Thanh Cong;Jung, Jae Cheon
    • 시스템엔지니어링학술지
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    • 제14권2호
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    • pp.58-66
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    • 2018
  • This paper represents a systematic approach aimed at improving the performance of the proportional integral (PI) controller for the Advanced Power Reactor (APR) 1400 Feedwater Control System (FWCS). When the performance of the PI controller offers superior control and enhanced robustness, the steam generator (SG) level is properly controlled. This leads to the safe operation and increased the availability of the nuclear power plant. In this paper, a systems engineering approach is used in order to design a novel PI controller for the FWCS. In the reverse engineering stage, the existing FWCS configuration, especially the characteristics of the feedwater controller as well as the feedwater flow path to each SG from the FWCS, were reviewed and analysed. The overall block diagram of the FWCS and the SG was also developed in the reverse engineering process. In the re-engineering stage, the actual design of the feedwater PI controller was carried out using a genetic algorithm (GA). Lastly, in the validation and verification phase, the existing PI controller and the PI controller designed using GA method were simulated in Simulink/Matlab. From the simulation results, the GA-PI controller was found to exhibit greater stability than the current controller of the FWCS.

The Adsorptions and Configurations of CO Molecules on W (110) and W (100) Surface: Molecular Orbital Theory

  • Choe, Sang-Joon;Kang, Hae-Jin;Park, Dong-Ho;Huh, Do-Sung;Lee, Soon-Bo
    • Bulletin of the Korean Chemical Society
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    • 제25권9호
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    • pp.1314-1320
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    • 2004
  • The adsorption and configuration of CO molecules adsorbed on W (110) and W (100) surfaces have been calculated by the atomic superposition and electron delocalization molecular orbital (ASED-MO) method. Referred to as the ASED-MO method, it has been used in the present study to calculate the geometries, binding energies, vibrational frequencies, orbital energies, reduced overlap population (ROP), and charges. From these results adsorption properties of ${\alpha}$-state and ${\beta}$-state were deduced. The calculated binding energies are in good agreement with the experimental result. On the W (110), the calculated average binding energies are 2.56 eV for the end-on configuration and 3.20 eV for the lying-down configuration. Calculated vibrational frequency is 1927 $cm^{-1}$ at a 1-fold site and 1161 $cm^{-1}$ at a long-bridge (2) site. These results are in reasonable agreement with experimental values. On the W(100) surface, calculated average binding energies of the end-on and the lying-down are 2.54 eV and 4.02 eV respectively. The differences for binding energy and configuration on the surfaces are explained on the basis of surface-atom coordination and atom-atom spacing. In the favored lyingdown CO configuration on the W(110) and W(100) surfaces, 4 ${\sigma}$ and 1 ${\pi}$ donation interactions, coupled with the familiar 5 ${\sigma}$ donation to the surfaces and back-donations to the CO 2 ${\pi}^{\ast}$ orbital, are responsible for adsorption to the surface.

Study of Optimized Condition for Bend State in Polymer Stabilized Pi-cell with Compensation Films

  • Jeong, Seung-Yeon;Shin, Hyun-Ho;Bos, Phil;Shin, Sung-Tae
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.589-594
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    • 2003
  • The pi-cell [1] is known as one of the candidates for a fast response time and a good viewing angle characteristics due to a self-compensated configuration and can be a replaceable mode instead of the current TN mode and the IPS mode for moving picture in future. This paper shows the optimized condition to maintain bend state instead of splay state, which is mortal demerit for good optical properties in a pi-cell, by using the polymer stabilized method [2]. The good electro-optical characteristics are also obtained by optimizing the various factors, which are monomer concentration in a LC, UV intensity, curing time, curing voltage, and curing temperature, and by using retardation film. We use a scanning electron microscope to study the structures of the polymer stabilized polymer network in a pi-cell as a key to figure out why bend state is occurred.

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Implementation of a Wi-Fi Based Cluster System using Raspberry Pi for Multidisciplinary Education

  • Koo, Geum-Seo;Sim, Gab-Sig
    • 한국컴퓨터정보학회논문지
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    • 제24권1호
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    • pp.1-7
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    • 2019
  • In this paper, we implemented a Wi-Fi based cluster system using raspberry pi for multidisciplinary education. The cluster implementation on the desktop was more difficult to maintain the complexity, big size, high price, power consumption as the number of nodes increased. In this paper, we implemented a cluster using Raspberry Pi, which is developed for educational purposes, to reduce the cost of connecting nodes. In addition, the complexity of system construction is reduced by replacing the connection between each node with Wi-Fi. Also, the inconvenience of configuration due to node increase was reduced. It is expected that the implementation of the cluster will be a good alternative in the educational environment where distributed processing and parallel processing are performed in the embedded environment. Also, it is confirmed that it can be applied to the multidisciplinary education.

리눅스에서 센서/구동기의 Plug&Play를 위한 USB장치 (A USB Device for Plug&Play of Sensor/Actuator In Linux)

  • Eun, Seongbae;So, Sun Sup
    • 한국정보통신학회논문지
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    • 제26권2호
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    • pp.329-332
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    • 2022
  • Since IoT devices include various sensors and drivers, application programmers need to understand the structure and characteristics of sensors and actuators. If the manufacturer provides the driver of the sensor or actuator, IoT development can be efficiently carried out, which is called the Plug & Play technique. What matters is that the technique proposed by this research team in the past are not suitable for Arduino or Raspberry-Pi, which are recently used. In this paper, we propose a USB sensor device that can be mounted on a Raspberry-Pi. When the device is plugged into the Raspberry-Pi, the built-in driver is transmitted and played. The configuration of the USB sensor device was presented, and considerations for chip selection for processing sensors and drivers were presented.