• Title/Summary/Keyword: Phase Diagram

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An Implementation Architecture for Knowledge Flow Model (지식 흐름 모델의 구현 아키텍처에 관한 연구)

  • Kim, Su-Yeon;Hwang, Hyun-Seok
    • Knowledge Management Research
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    • v.7 no.2
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    • pp.53-68
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    • 2006
  • Knowledge has become an important resource for organization. The manufacturing industry is usually operated on the basis of business processes, and most workers are familiar with their own processes. The process-based approach, therefore, can provide an efficient way to capture and navigate knowledge. In this study, we focus on knowledge which may be missed during knowledge transfer among workers. For this, we propose a method for analyzing knowledge flow, which is passed among business processes. We propose a process-based knowledge management framework for analyzing knowledge flow, which employs a two-phase analysis: process analysis and knowledge flow analysis. A knowledge flow model, represented by Knowledge Flow Diagram, is proposed as a tool for representing knowledge. We formulate several semantics for knowledge flow modeling. We build the three-level schema: conceptual, logical, and physical in order to automate the knowledge model adaptive to knowledge management systems. The proposed approach is verified and illustrated through a case study on the manufacturing process of A Company.

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The characteristics of the Ringbom Stirling engine (Ringbom 스터링 엔진의 제작 및 특성 연구)

  • Lee, Sang-Won;Cho, Kyung-Chul;Won, Min-Young;Kim, Soo-Yun;Jung, Pyung-Suk
    • Proceedings of the KSME Conference
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    • 2001.06d
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    • pp.660-664
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    • 2001
  • Ringbom Stirling engine which is a kind of low temperature difference model Stirling engine is manufactured and its characteristics are measured at some temperature differences. Pressure, displacer position and rotation speed are measured. Displacer position and rotation speed are detected by photo-sensor. The hot side of Ringbom Stirling engine is warmed by electric heater. The cold side of Ringbom Stirling engine is cooled by the air. This result may be useful for further design and manufacture of Ringbom Stirling engine. Also, it would be used as an educational material for mechanical engineering students.

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Transient Buoyant Flows of a Stratified Fluid in a Vertical Channel

  • Park, Jun-Sang
    • Journal of Mechanical Science and Technology
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    • v.15 no.5
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    • pp.656-664
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    • 2001
  • A theoretical analysis is performed to describe the qualitative behavior of transient buoyant flows in a vertical channel. Consideration is given to the case of a fluid with a pre-existing stratification. The fluid motion is generated by giving impulsive anti-symmetric step-changes in temperature at the vertical left ad right sidewalls. The qualitative character of the flow is shown to be classified in the Rayleigh number (Ra)-Prandtl number ($sigma$) diagram. The transitory approach to the steady state can be monotonic or oscillatory, depending on ($sigma$-1)$^2$$pi$$^4$ 4$sigma$$R_a$. The prominent characteristics of time-dependent flow are discussed for large $R_a$. The profiles of temperature and velocity in the transient phase are depicted, which disclose distinctive time scales of motion. The transient process is shown to be sensitive to the Prandtl number. The detailed evolutions of flow and temperature fields are illustrated for large $R_a$.

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Evaluation of DoP-CPD Classification Technique and Multi Looking Effects for RADARSAT-2 Images

  • Lee, Kyung-Yup;Oh, Yi-Sok;Kim, Youn-Soo
    • Korean Journal of Remote Sensing
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    • v.28 no.3
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    • pp.329-336
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    • 2012
  • This paper give further assessment on the original DoP-CPD classification scheme. This paper provides some additional comparative study on the DoP-CPD with H/A/alpha classifier in terms of multi look effects and classification performances. The statistics and multi looking effects of the DoP and CPD were analyzed with measured polarimetric SAR data. DoP-CPD is less sensitive to the number of averaging pixels than the entropy-alpha technique. A DoP-CPD diagram with appropriate boundaries between six different classes was then developed based on the data analysis. A polarimetric SAR image DoP-CPD classification technique is verified with C-band polarimetric RADARSAT-2 images.

A study on the development of Ti-Cu-Ni-Si insert metal for Ti alloys (Ti합금 접합용 Ti-Cu-Ni-Si계 삽입금속의 개발에 관한 연구)

  • 김경미;우인수;강정윤;이상래
    • Journal of Welding and Joining
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    • v.14 no.1
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    • pp.47-56
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    • 1996
  • The purpose of this study is to develope an insert metal which can be brazed at lower temperature than the conventionally used insert metal and provide higher strength joint than base metal. In the review of binary phase diagram concerning Ti, Cu and Ni resulted in the discovery of Si having eutectic composition with them. The microstructure and the distribution of elements in reaction zone between CP Ti and insert metal were investigated by Optical Microscopy, SEM/EDX, EPMA, X-RAY. The newly developed insert metal is Ti-15wt%Cu-18wt%Ni-2wt%Si, which can yield the lower brazing temperature(1183K) compared with the conventional Ti-Cu-Ni system insert metal. The joints with this insert metal had tensile strength of 385MPa in the bonding temperature range of 1183K to 1243K.

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Selection Method of Alternatives for Considering Correlation between Component Elements in Remodeling Design Process (리모델링 설계단계에서 부위구성요소의 상관관계를 고려한 대안선정 방법)

  • Park Chan-Gil;Chun Jae-Youl
    • Korean Journal of Construction Engineering and Management
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    • v.5 no.1 s.17
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    • pp.53-61
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    • 2004
  • As remodeling project is progressed in the constraint which is utilization of existing resource, the subject of remodeling and extend of construction are affected by the correlation between building element. Therefore, this research analyze the correlation between component of building element in the design phase and proposed the diagram model for correlation between building element and proposed selection method of alternative plan for optimized combination of building element in remodeling project.

Nonlinear Rocking Vibration Characteristics for Rigid Block Subjected to Horizontal Sinusoidal Excitation (수평방향의 정현파 가진을 받는 강체 블록의 비선형 록킹진동특성)

  • 정만용;김정호;김지훈;정낙규;양인영
    • Journal of the Korean Society of Safety
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    • v.14 no.4
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    • pp.3-12
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    • 1999
  • This research concentrates on the influence of non-linearities associated with impact for the nonlinear rocking behavior of rigid block subjected to one dimensional sinusoidal excitation of horizontal direction. The transition of two governing rocking equations, the abrupt reduction in the kinetic energy associated with impact, and sliding motion of block. In this study, two type of rocking vibration system are considered. One is the undamped rocking vibration system, disregarding energy dissipation at impact and the other is the damped rocking system, including energy dissipation and sliding motion. The response analysis using non-dimensional rocking equation is carried out for the change of excitation parameters and friction coefficient. The chaos responses were discovered in the wide response region, particularly, for the case of high excitation amplitude and their chaos characteristics were examined by the time history, Poincare map, power spectra and Lyapunov Exponent of rocking responses. The complex behavior of chaos response, in the phase space, were illustrated by Poincare map. The bifurcation diagram and Poincare map were shown to be effective in order to understand chaos of rocking system.

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Switching Noise Reduction in Radiated from Three-Phase Induction Motor by Chaotic Random PWM Technique (카오스 랜덤 PWM기법을 이용한 3상 유도모터의 스위칭 소음저감)

  • Kim, J.H.;Jung, Y.G.;Oh, S.Y.;Lim, Y.C.
    • Proceedings of the KIEE Conference
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    • 2004.10a
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    • pp.134-138
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    • 2004
  • 본 연구에서는 카오스 랜덤 PWM(Chaotic Random PWM) 기법에 의한 3상 유도모터의 스위칭 소음 저감에 대하여 다루고 있다. 일반적으로 사용되고 있는 랜덤 발생기로서 선형일치발생기(Linear Congruential Generator : LCG)대신에 로지스트 사상(Logistic Map)의 분기도(Bifurcation Diagram)를 랜덤 발생기로 사용하였다. 카오스 랜덤수 발생기는 80C196 마이크로 콘트롤러가 전담하고 있으며, 80C196으로부터 발생된 카오스랜덤 수와 MAX038에 의하여 삼각파 랜덤 캐리어가 발생되고 있다. 1.5kw급 3상 유도모터 구동 시스템에 카오스 RPWM기법을 적용하여 모터전압 및 전류 그리고 스위칭 소음의 스펙트럼을 고찰하였다. 카오스 RPWM과 LCG에 의한 RPWM의 결과를 각각 비교하였으며 본 연구의 타당성을 입증하였다.

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A Case Study of Six Sigma Project for Reducing the Project Costs through Project Risk Management (프로젝트 위험관리강화를 통한 원가개선의 6시그마 사례)

  • Jung, Ha-Sung;Lee, Dong-Wha;Lee, Min-Koo
    • Journal of Korean Society for Quality Management
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    • v.33 no.3
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    • pp.135-148
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    • 2005
  • This paper considers a six sigma project for reducing the project costs through project risk management. The project follows a disciplined process of five phases: define, measure, analyze, improve, and control. A risk management process map is used to identify process input and output variables. Seven key process input variables are selected by using C&E diagram and X-Y matrix and finally four vital few input variables are selected by the related statistical analysis. The optimum alternatives of the vital few input variables are obtained by the method of PUGH matrix. The process is running on control plan and we obtained substantial project cost reductions in early stage of the control phase.

Evaluation of the Inputs Efficiency for the Interior Noise of the Vehicle using Vector Synthesis Method (벡터합성법을 이용한 차량 실내소음의 입력원 영향도 평가)

  • Yang, In-Hyung;Jeong, Jae-Eun;Oh, Jae-Eung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.6
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    • pp.562-567
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    • 2010
  • A passenger vehicle has various and complicated transmission paths of sound and vibration. In order to identify the mechanism of transfer path, estimation of excitation force and exact modeling of transfer path are required. In this paper vector synthesis technique is employed to identify the characteristics of road noise and its transmission to vehicle compartment through noise and vibration analysis. Vibration reduction efficiency of each transfer path is evaluated by comparing individual vector components obtained virtual simulation. The degree of effect is used to estimate the contribution of vibration input components to total output. And in this paper presents a new technique based on simulation studies using vector synthesis diagram and design of experiments, by which the effects of magnitude and phase change of input paths can be predicted.