• Title/Summary/Keyword: Reference

Search Result 21,729, Processing Time 0.046 seconds

Preparation and Characterization of a Surface Renewable Solid State Hg/HgO Reference Electrode Utilizing Gold Amalgam

  • Kim, Won;Park, Jong-Man
    • Bulletin of the Korean Chemical Society
    • /
    • v.28 no.3
    • /
    • pp.439-442
    • /
    • 2007
  • A solid state Hg(Au)/HgO reference electrode was prepared utilizing gold amalgam solid particles. Solid fine powder of the gold amalgam was prepared by chemical reduction of Au(III) with NaBH4 followed by reduction of Hg(II) in the presence of gold fine particles. The solid content in the suspension of the gold amalgam particles and fine mercury oxide particles in DMF containing PVC was precipitated by the addition of a large amount of water to give solid Hg(Au)/HgO/PVC mixture. After drying, the mixture was pressure-molded to a physically stable Hg(Au)/HgO composite reference electrode material. The electrochemical characteristics of the electrode as a reference electrode were very similar to an ordinary Hg/HgO reference electrode. The electrode material can be molded and fabricated in any desired shape and size. The surface can be renewed by a simple polishing process whenever contaminated or deactivated. The applicability of the electrode in the electrochemical detection of carbohydrates after anion exchange separation was evaluated.

Vibration Analysis of Rotating Structures Employing Multi-Reference Frames (다중 기준틀을 사용한 회전 구조물의 진동해석)

  • 김정민;유홍희
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2004.05a
    • /
    • pp.814-819
    • /
    • 2004
  • In this paper, a modeling method for the vibration analysis of rotating structures employing multi-reference frames is presented. The geometric stiffening effect that results from centrifugal inertia force is considered. In most previous studies single reference frame has been employed for the analysis. In the present study, a modeling method employing multi-reference frames is presented, and the effects of employing multi-reference frames on the analysis accuracy are investigated through solving numerical examples.

  • PDF

Calculation of a reference force for feedrate scheduling using the FEM analysis of a tool (엔드밀링 공구의 유한요소해석을 통한 이송속도 스케줄링의 기준 절삭력 산출)

  • 이한울;조동우
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
    • /
    • 2004.10a
    • /
    • pp.416-421
    • /
    • 2004
  • Off-line feedrate scheduling is presented as the advanced technology to regulate cutting forces at the desired level through change of feedrates. In rough cutting, the feedrate scheduling aims at reducing the machining time, which is the most important factor for better productivity. Thus, the largest force which can avoid breakage of tool shank and tooth is a reference force for feedrate scheduling in rough cutting. In this paper, a calculation method of the reference cutting force for feedrate scheduling is developed. This model calculates rupture plane of tooth using the FEM analysis of a tool and computes the reference force using the transverse rupture strength of a tool. Experiments validate that the presented feedrate scheduling model reduced machining time drastically and regulate cutting forces at the reference cutting force.

  • PDF

On the Trends and Ruminations of Managerial Reforms in Academic Libraries (대학도서관 경영개혁의 동향과 반추 -조직의 통함과 팀제를 중심으로-)

  • 윤희윤
    • Journal of Korean Library and Information Science Society
    • /
    • v.32 no.1
    • /
    • pp.33-51
    • /
    • 2001
  • University libraries need the development of a common Internet-based reference request system in order to prevent duplicated investment and provide interoperability among them. This paper proposes a standard of Internet-based reference recluest system that serves reference request-responses and that provides reference source sites on the world wide web. Using this system, university libraries can cooperate other libraries with reference databases and may perform tasks of reference service efficiently.

  • PDF

Zoom Motion Estimation Method for Depth Video Coding (깊이 영상 부호화에서 신축 움직임 추정 방법)

  • Lee, Dong-Seok;Kwon, Soon-Kak
    • Journal of Korea Multimedia Society
    • /
    • v.20 no.11
    • /
    • pp.1711-1719
    • /
    • 2017
  • In this paper, we propose a method of the zoom motion estimation for the depth video coding. The proposed method calculates the zoom ratio using the average of the depth values in the current block and in the reference block. It resizes the reference block by the zoom ratio and interpolates the reference block to size of the current block. It compares the current block with the reference block that is obtained by subtracting the average of pixels from the current block to the reference block in order to find the reference block that is the best closest one to the current block. The results of the simulation for the proposed method show that the motion estimation errors are significantly reduced.

Active Vibration Control of a Opened Box Structure By a Model Reference Neuro-Controller (모델기반 신경망 제어기를 이용한 열린 박스 구조물의 진동제어)

  • Jang, Seung-Ik;Shen, Yun-De;Kee, Chang-Doo
    • Proceedings of the KSME Conference
    • /
    • 2003.11a
    • /
    • pp.1602-1607
    • /
    • 2003
  • Vibration causes noise and sometimes makes structure unstable. Especially, due to the efforts of lightening, deformation of flexible structure is increased in its shape. Just a little disturbance can cause vibration and low damping ratio makes residual vibration last long time. This research is concerned with the model reference neuro-controller design for the vibration suppression of smart structures. By using a model reference neurocontroller, which is one of the algorithms of adaptive control, we performed an adaptive control of flexible cantilever plate and opened box structure with piezoelectric materials. The proposed adaptive vibration control algorithm, a model reference neuro-controller, was proved in its effectiveness by applying to an opened box structure. The model reference neuro-controller is implemented with DSP, and the real-time adaptive vibration control experiment results confirm that the model reference neuro-controller is reliable.

  • PDF

The Reference Wave Generator for Dynamic Voltage Restorers by use of PQR Instantaneous Power Theory (PQR 순시전력이론에 의한 동적전압보상기의 기준파 발생기)

  • 김효성;이상준;설승기
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.8 no.5
    • /
    • pp.435-441
    • /
    • 2003
  • Dynamic Voltage Restorers (DVR)s are known as the best effective and economic means to compensate for voltage sags and swells. This paper proposes a novel method to generate reference voltages synchronized with the grid whether the line voltages are distorted by a fault or not. The proposed reference wave generator (RWG) looks for the original wave forms from the corrupted line voltages and synthesizes the expected positive sequence reference waves for DVRs. There is no transient problem on the generated reference waves when the line voltages are distorted by the fault.

Software PLL Based Speed Control of High Speed Miniature BLDC (소프트웨어 PLL 기반 소형 고속 BLDC의 속도 제어)

  • Park, Tae-Hub;Seok, Seung-Hun;Lee, Dong-Hee;Ahn, Jin-Woo
    • Proceedings of the KIEE Conference
    • /
    • 2008.10c
    • /
    • pp.132-135
    • /
    • 2008
  • This paper presents a PLL(Phase Lock Loop) control method for speed control of high speed miniature BLDCM(Brushless DC Motor) using hall sensor. The Proposed PLL based speed control method uses a only phase shift between reference pulse signal according to speed reference and actual pulse signal from hall sensor. It doesn't use any speed calculation, and calculates a direct current reference from phase shift. The current reference is changed to reduce the phase shift between reference and actual pulse. So the actual speed can keep the reference speed. The proposed control scheme is very simple but effective speed control is possible.

  • PDF

Vibration Analysis of Rotating Structures Employing Multi-reference Frames (다중 기준틀을 사용한 회전 구조물의 진동해석)

  • 김정민;유홍희
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.14 no.10
    • /
    • pp.983-989
    • /
    • 2004
  • In this paper, a modeling method for the vibration analysis of rotating structures employing multi-reference frames is presented. The geometric stiffening effect that results from centrifugal inertia force is considered. In most previous studies single reference frame has been employed for the analysis. In the present study, a modeling method employing multi-reference frames is presented, and the effects of employing multi-reference frames on the analysis accuracy are investigated through solving numerical examples.

Library Cooperation for Reference Service (참고봉사를 위한 도서관의 상호협력 -미국의 사례를 중심으로-)

  • Noh Ock-Soon
    • Journal of the Korean Society for Library and Information Science
    • /
    • v.3
    • /
    • pp.25-46
    • /
    • 1973
  • The recent situation on developments in an expanding field of reference and information service is reviewed through the cooperative arrangements and comprehensive planning among libraries in America. The growth of reference cooperation is examined first along with the social forces that influenced the library interdependence for service. Of the various interlibrary programs identified in relation to the cooperative reference work, interlibrary loan is viewed as the key to the use of library resources based on equal access and making use of the tools for information and research, therefore a reference principle. Several kinds of library systems specifically intended to improve the reference situation are identified and described in detail without any attempt to evaluate their performance in terms of unit size, cost, or quality of the service.

  • PDF