• Title/Summary/Keyword: J-$A_2$Theory

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A Study on Structure Analysis and Fatigue Life of the Common Rail Pipe (커먼레일 파이프의 구조해석 및 피로수명에 관한 연구)

  • Song, M.J.;Jung, S.Y.;Hwang, B.C.;Kim, C.
    • Transactions of Materials Processing
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    • v.19 no.2
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    • pp.88-94
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    • 2010
  • The next generation of diesel engine can operate at high injection pressure up to 1,800bar. The common rail pipe must have higher internal strength because it is directly influenced by the high-pressure fuel. Folding defects in the Common rail pipe can not ensure the structural safety. Therefore, Preform design and fatigue-life analysis are very important for preventing the head of the common rail pipe from folding in the heading process and for predicting fatigue life according to the amount of folding. In this study, a closed form equation to predict fatigue life was suggested by Goodman theory and pressure vessels theory in ASME Code in order to develop an optimization technique of the heading process and verified its reliability through fatigue-structural coupled field analysis. The results calculated by the theory were in good agreement with those obtained by the finite element analysis.

Predicting Discharge Rate of After-care patient using Hierarchy Analysis

  • Jung, Yong Gyu;Kim, Hee-Wan;Kang, Min Soo
    • International Journal of Advanced Culture Technology
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    • v.4 no.2
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    • pp.38-42
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    • 2016
  • In the growing data saturated world, the question of "whether data can be used" has shifted to "can it be utilized effectively?" More data is being generated and utilized than ever before. As the collection of data increases, data mining techniques also must become more and more accurate. Thus, to ensure this data is effectively utilized, the analysis of the data must be efficient. Interpretation of results from the analysis of the data set presented, have their own on the basis it is possible to obtain the desired data. In the data mining method a decision tree, clustering, there is such a relationship has not yet been fully developed algorithm actually still impact of various factors. In this experiment, the classification method of data mining techniques is used with easy decision tree. Also, it is used special technology of one R and J48 classification technique in the decision tree. After selecting a rule that a small error in the "one rule" in one R classification, to create one of the rules of the prediction data, it is simple and accurate classification algorithm. To create a rule for the prediction, we make up a frequency table of each prediction of the goal. This is then displayed by creating rules with one R, state-of-the-art, classification algorithm while creating a simple rule to be interpreted by the researcher. While the following can be correctly classified the pattern specified in the classification J48, using the concept of a simple decision tree information theory for configuring information theory. To compare the one R algorithm, it can be analyzed error rate and accuracy. One R and J48 are generally frequently used two classifications${\ldots}$

Searching Algorithms for Protein Sequences and Weighted Strings (단백질 시퀀스와 가중치 스트링에 대한 탐색 알고리즘)

  • Kim, Sung-Kwon
    • Journal of KIISE:Computer Systems and Theory
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    • v.29 no.8
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    • pp.456-462
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    • 2002
  • We are developing searching algorithms for weighted strings such as protein sequences. Let${\sum}$ be an alphabet and for each $a{\in}{\sum}$ its weight ${\mu}(a)$ is given. Given a string $A=a_1a_2…a_n\; with each ai{\in}{\sum}$, a substring<$A(i.j)=a_ia_{i+1}…a_j$ has weight ${\in}(A(i.j))={\in}(a_i)+{\in}(a_i+1)+…+{\in}(a_j)$.The problem we are dealing with is to preprocess A to build a searching structure, and later, given a query weight M, the structure is used to answer the question of whether there is a substring A(i,j) such that$M={\in}(A(i,j))$.In this paper an algorithm that improves over the previous result will be presented. The previously best known algorithm answers a query in $0(\frac{nlog\;logn}{log\; n})$time using a searching structure that requires O(n) amount of memory. Our algorithm reduces the memory requirement to $0(\frac{n}{log\; n})$ while achieving the same query answer time.

A study of wind turbine power generation and turbine/tower interaction using large eddy simulation

  • Howard, R.J.A.;Pereira, J.C.F.
    • Wind and Structures
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    • v.9 no.2
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    • pp.95-108
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    • 2006
  • Wind turbines are highly complex structures for numerical flow simulation. They normally comprise of a turbine mounted on a tower thus the movement of the turbine blades and the blade/tower interaction must be captured. In addition the ground effect should also be included. There are many more important features of wind turbines and it is difficult to include all of them. A simplified set of features is chosen here for both the turbine and the tower to show how the method can begin to identify the main points connected with wind turbine wake generation and tip vortex tower interaction. An approach to modelling the rotating blades of a turbine is proposed here. The model uses point forces based on blade element theory to model the blades and takes into account their time dependent motion. This means that local instantaneous velocities can be used as a basis for the blade element theory. The model is incorporated into a large eddy simulation code and, although many important features are left out of the model, the velocity/power performance relation is generally of the correct order of magnitude. Suggested improvements to the method are discussed.

A Study of MMOPRG Background Story based on Fantasy Theory (환상의 범주에 따른 MMORPG의 세계관 연구)

  • Ahn, Jin-Kyoung;Lyou, Chul-Gyun
    • Journal of Digital Contents Society
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    • v.9 no.2
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    • pp.349-356
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    • 2008
  • MMORPG which offers a utopian world that includes a different rule from the real to satisfy players' needs for escape from the real world has changed. In these days, MMORPGs which have a unique world than middle-age fantasy have appeared as a new experience field. This paper compares MMORPGs have a middle-aged fantasy background story like J.R.R. Tolkein with another types bases on fantasy theory and presents difference.

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ASYMPTOTIC BEHAVIOUR OF THE SOLUTIONS OF LINEAR IMPULSIVE DIFFERENTIAL EQUATIONS

  • Simeonov, P.S.;Bainov, D.D.
    • Bulletin of the Korean Mathematical Society
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    • v.31 no.1
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    • pp.1-14
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    • 1994
  • In the recent several years the theory of impulsive differential equations has made a rapid progress (see [1] and [2] and the references there). The questions of stability and periodicity of the solutions of these equations have been elaborated in sufficient details while their asymptotic behaviour has been little studied. In the present paper the asymptotic behaviour of the solutions of linear impulsive differential equations is investigated, generalizing the results of J. W. Macki and J.S. Muldowney, 1970 [3], related to ordinary differential equations without impulses.

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Ductile Fracture Behaviour of SPS Specimen Under Pure Mode II Loading (순수 모드 II하중 하에서의 SPS 시험편의 연성파괴 특성에 관한 연구)

  • O, Dong-Jun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.2
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    • pp.289-295
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    • 2001
  • The aim of this study is to investigate the ductile fracture behaviour under pure Mode II loading using A533B pressure vessel steel. Single punch shear(SPS) test was performed to obtain the J-R curve under pure Mode II loading which was compared with that of the Model I loading. Simulation using Rousellier Ductile Damage Theory(RDDT) was carried out with 4-node quadrilateral element(L(sub)c=0.25mm). For the crack advance, the failed element removal technique was adopted with a $\beta$ criterion. Through the $\beta$ value tuning-up procedures, $\beta$(sub)crit(sup)II was determined as 1.5 in contrast with $\beta$(sub)crit(sup)I=5.5. In conclusion, it was found that the J-R curve under Mode II loading was located at lower part than that under Mode I loading obtained from the previous study and that the $\beta$ values strongly depended on the loading type. In addition, the predicted result using RDDT showed a good agreement with the SPS experimental one under pure Mode II loading.

The Parameter Identification for Localization Scheme of the Optics-Based Micro Sensor Node (광신호 기반의 마이크로 센서 노드 위치 인식 시스템을 위한 파라미터 식별)

  • Jeon, Ji-Hun;Lee, Min-Su;Park, Chan-Gook
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.2
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    • pp.81-86
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    • 2013
  • In this paper, the parameter identification for localization scheme for the optics-based micro sensor node is conducted. We analyzed short measurement range problem which can be occurred in optical based micro sensor node localization method using a time of flight. And we set up the theory for distance and maximum reflected laser power to overcome the problem by identifying hardware parameters like laser power, effective area of MEMS CCR, sensitivity of photodetector, and so on. Experimental results of measurement of maximum reflected laser power were compared with results of the theory. By using the theory, we can identify hardware parameters of localization scheme to measure particular position of the optics-based micro sensor node.

A thermal microwave emission model for row-structured vegetation (이방성 물질의 마이크로파대역 열 발산 모델)

  • Eom, Hyo J.
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.3 no.2
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    • pp.40-45
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    • 1992
  • A simple emission model applicable for low scattering (scattering << absorption) anisotropic layer is developed and applied to the interpretation of measurements of microwave emission from row crops. The vegetation layer of row crops is modeled as a random slab embedded with small spheroid with major axis aligend paralel to the crop-row direction. The total emission is given in a simple algebraic form based on the zero-order radiative transfer theory. The single scattering albedo for spheroid and its polarimetric phase function are presented. The effects of layer azimuthal dependence on emission are accounted for by using an anisotropic albedo in the zero-order transfer theory. The developed emission theory favorably compares with the brightness temperature measured over soybeans canopy.

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A Study on the Angle of Localization of a Metal Specimen under Uniaxial Tension with Plane Strain Condition (평면 변형 조건에서 일축 인장력을 받는 금속 재료의 불연속 변위 각에 대한 연구)

  • Park, Jae-Gyun;Kim, Mi-Rim
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.24 no.3
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    • pp.275-281
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    • 2011
  • When a flat bar type metal specimen for general tension test is subject to incremental uniaxial tension, a narrow plastic shear band, so called luders band, is generated at some instance. This band typically has an angle to the axis of specimen and many early researches have been done to investigate the condition and angle of this localized deformation phenomenon by many researchers. This study follows the procedure of Thomas(1961) under plane stress boundary condition. $J_2$ plasticity theory, balance of linear momentum, and constitutive equations are used to derive the angle of luders band under plain strain boundary condition. The result was confirmed by other angle based on acoustic tensor theory.