• Title/Summary/Keyword: Structure and function

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Passive control of seismically excited structures by the liquid column vibration absorber

  • Konar, Tanmoy;Ghosh, Aparna Dey
    • Structural Engineering and Mechanics
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    • v.36 no.5
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    • pp.561-573
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    • 2010
  • The potential of the liquid column vibration absorber (LCVA) as a seismic vibration control device for structures has been explored in this paper. In this work, the structure has been modeled as a linear, viscously damped single-degree-of-freedom (SDOF) system. The governing differential equations of motion for the damper liquid and for the coupled structure-LCVA system have been derived from dynamic equilibrium. The nonlinear orifice damping in the LCVA has been linearized by a stochastic equivalent linearization technique. A transfer function formulation for the structure-LCVA system has been presented. The design parameters of the LCVA have been identified and by applying the transfer function formulation the optimum combination of these parameters has been determined to obtain the most efficient control performance of the LCVA in terms of the reduction in the root-mean-square (r.m.s.) displacement response of the structure. The study has been carried out for an example structure subjected to base input characterized by a white noise power spectral density function (PSDF). The sensitivity of the performance of the LCVA to the coefficient of head loss and to the tuning ratio have also been examined and compared with that of the liquid column damper (LCD). Finally, a simulation study has been carried out with a recorded accelerogram, to demonstrate the effectiveness of the LCVA.

The Internal Structure of an Identification Function in Korean Lexical Pitch Accent in North Kyungsang Dialect

  • Kim, Jungsun
    • Phonetics and Speech Sciences
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    • v.5 no.1
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    • pp.91-98
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    • 2013
  • This paper investigated Korean prosody as it relates to graded internal structure in an identification function. Within Korean prosody, variants regarded as dialectal variations can appear as different prosodic scales, which contain the range of within-category variations. The current experiment was intended to show how the prosodic scale corresponding to the range of within-category differences relates to f0 contours for speakers of two Korean dialects, North Kyungsang and South Cholla. In an identification task, participants responded by selecting an item from two answer choices. The probability of choosing the correct response from the two choices was computed by a logistic regression analysis using intercepts and slopes. That is, the correct response between two choices was used to show a linear line with an s-shape presentation. In this paper, to investigate the graded internal structure of labeling, 25%, 50%, and 75% of predicted probability were assessed. Listeners from North Kyungsang showed progressive variations, whereas listeners from South Cholla revealed random patterns in the internal structure of the identification function. In this paper, the results were plotted using scatterplot graphs, applying the range of within-category variation and predicted probability obtained from the logistic regression analyses. The scatterplot graphs showed the different degree of the responses for f0 scales (i.e., variations within categories). The results demonstrate that the gradient structures of native pitch accent users become more progressive in response to f0 scales.

Design Automatization of Space Truss Structure Using Optimizations Technique (최적화 기법을 이용한 3차원 트러스 구조물의 설계자동화)

  • 최은규;임기식;이병해
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1993.10a
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    • pp.81-90
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    • 1993
  • The optimum design of a structure requires the determination of the economical member size and shape of the structure which satisfies the design condition and function. In this study, the process of design automatization of three-dimensional truss structure introduces the optimization technique tests its application in the design automatization, proposes its application method and applies the example structure of the parabolic antenna truss. Using the Formex Algebra of configuration function, the structure's mesh-generation is automatized. By using the program developed in this study, the input member array, member size and load condition designer can generate the input data file for the structure analysis and optimum design. This study is aimed at the development of a design automatization system that search for tile optimum value of a structure design by observing the structure's sensitivity from the modification of member array and member property.

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Bioinformatic approaches for the structure and function of membrane proteins

  • Nam, Hyun-Jun;Jeon, Jou-Hyun;Kim, Sang-Uk
    • BMB Reports
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    • v.42 no.11
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    • pp.697-704
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    • 2009
  • Membrane proteins play important roles in the biology of the cell, including intercellular communication and molecular transport. Their well-established importance notwithstanding, the high-resolution structures of membrane proteins remain elusive due to difficulties in protein expression, purification and crystallization. Thus, accurate prediction of membrane protein topology can increase the understanding of membrane protein function. Here, we provide a brief review of the diverse computational methods for predicting membrane protein structure and function, including recent progress and essential bioinformatics tools. Our hope is that this review will be instructive to users studying membrane protein biology in their choice of appropriate bioinformatics methods.

General Method of Equivalent Damping Ratio Evaluation of a Structure equipped with Response Dampers (응답감쇠장치가 설치된 구조물의 등가감쇠비산정에 관한 일반적인 방법)

  • 민경원;이영철;이상현
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.05a
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    • pp.109-114
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    • 2002
  • The purpose of this study is to propose the general method for evaluating the equivalent damping ratios of a structure with supplemental response control dampers. We define Lyapunov function of which derivative can be expressed in autoregressive form and evaluate the equivalent damping ratios by using Lyapunov function and its derivative. This Lyapunov function may be called as generalized structural energy. In this study, it is assumed that the response of a structure is stationary random process and control dampers do not affect the modal shapes of a structure, and the structure has proportional damping. Proposed method can be used to get the equivalent damping ratios of a structure with non-linear control dampers such as friction dampers as well as linear control dampers. To show the effectiveness of the proposed method. we evaluate the equivalent damping ratios of a structure with viscous dampers. AMDs. and friction dampers. The equivalent damping ratios from proposed method are compared to those from eigenvalue analysis for linear control dampers. and those from time history analysis for non-linear control dampers. respectively.

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Region-based Vessel Segmentation Using Level Set Framework

  • Yu Gang;Lin Pan;Li Peng;Bian Zhengzhong
    • International Journal of Control, Automation, and Systems
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    • v.4 no.5
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    • pp.660-667
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    • 2006
  • This paper presents a novel region-based snake method for vessel segmentation. According to geometric shape analysis of the vessel structure with different scale, an efficient statistical estimation of vessel branches is introduced into the energy objective function, which applies not only the vessel intensity information, but also geometric information of line-like structure in the image. The defined energy function is minimized using the gradient descent method and a new region-based speed function is obtained, which is more accurate to the vessel structure and not sensitive to the initial condition. The narrow band algorithm in the level set framework implements the proposed method, the solution of which is steady. The segmentation experiments are shown on several images. Compared with other geometric active contour models, the proposed method is more efficient and robust.

A Production Function for the Organization with Hierarchical Network Queue Structure (계층적(階層的) 네트웍 대기구조(待機構造)를 갖는 조직(組織)의 생산함수(生産函數)에 대한 연구(硏究))

  • Gang, Seok-Hyeon;Kim, Seong-In
    • Journal of Korean Institute of Industrial Engineers
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    • v.12 no.1
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    • pp.63-71
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    • 1986
  • In the organization with a hierarchical network queue structure a production function is derived whose input factors are the numbers of servers at nodes and output is the number of served customers. Its useful properties are investigated. Using this production function, the contributions of servers to the number of served customers are studied. Also given an expected waiting time in the system for each customer, the optimal numbers of servers at nodes are obtained minimizing a cost function.

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"A Study of Farbricating Full Denture, Which is Used Functional Imp and Zero-degree Artificial Poster Teeth" (의치주위조직(義齒周圍組織)의 기능인상(機能印象) 채득법에 의한 0$^{\circ}$ 구치(臼齒)의 Full Denture 제작법(製作法))

  • Kim, Ui-Nam
    • Journal of Technologic Dentistry
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    • v.7 no.1
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    • pp.33-40
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    • 1985
  • When full denture is being fabricated, pronounciation, recovery of aesthetics of function and mastificatory function should be satisfies for patients. To satisfy for the function of denture, following is the difference between this new way of fabricating and formerly one of it. 1. The size of fabricating tooth which is harmony of original oral structure for patients is deaded by manufacturing labial index and artificial tongue. 2. By the use of artificial tongue and labial index, the arranges of artificial tooth is to become harmony of oral structure. 3. Formation of gingival decided functional impression which is used by impression paste, is harmony of oral structure. Therefore, this full denture can be satisfied with pronouncing oral function of recovery of aesthetics as well as mastificatory through physiological movement of oral tissue not disturbed with anything but cooperated drastically. In manufacturing of this full denture, both dentist and dental technician under cooperation need to proceed the work on the base of importance of communication.

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Understanding Enzyme Structure and Function in Terms of the Shifting Specificity Model

  • Britt, Billy Mark
    • BMB Reports
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    • v.37 no.4
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    • pp.394-401
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    • 2004
  • The purpose of this paper is to suggest that the prominence of Haldane's explanation for enzyme catalysis significantly hinders investigations in understanding enzyme structure and function. This occurs despite the existence of much evidence that the Haldane model cannot embrace. Some of the evidence, in fact, disproves the model. A brief history of the explanation of enzyme catalysis is presented. The currently accepted view of enzyme catalysis -- the Haldane model -- is examined in terms of its strengths and weaknesses. An alternate model for general enzyme catalysis (the Shifting Specificity model) is reintroduced and an assessment of why it may be superior to the Haldane model is presented. Finally, it is proposed that a re-examination of many current aspects in enzyme structure and function (specifically, protein folding, x-ray and NMR structure analyses, enzyme stability curves, enzyme mimics, catalytic antibodies, and the loose packing of enzyme folded forms) in terms of the new model may offer crucial insights.

A Robust Control with a Neural Network Structure for Uncertain Robot Manipulator

  • Han, Myoung-Chul
    • Journal of Mechanical Science and Technology
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    • v.18 no.11
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    • pp.1916-1922
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    • 2004
  • A robust position control with the bound function of neural network structure is proposed for uncertain robot manipulators. The uncertain factors come from imperfect knowledge of system parameters, payload change, friction, external disturbance, and etc. Therefore, uncertainties are often nonlinear and time-varying. The neural network structure presents the bound function and does not need the concave property of the bound function. The robust approach is to solve this problem as uncertainties are included in a model and the controller can achieve the desired properties in spite of the imperfect modeling. Simulation is performed to validate this law for four-axis SCARA type robot manipulator.