• Title/Summary/Keyword: process control techniques

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Optimal Design of Robust Quantitative Feedback Controllers Using Linear Programming and Genetic Algorithms

  • Bokharaie, Vaheed S.;Khaki-Sedigh, Ali
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.428-432
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    • 2003
  • Quantitative Feedback Theory (QFT) is one of most effective methods of robust controller design and can be considered as a suitable method for systems with parametric uncertainties. Particularly it allows us to obtain controllers less conservative than other methods like $H_{\infty}$ and ${\mu}$-synthesis. In QFT method, we transform all the uncertainties and desired specifications to some boundaries in Nichols chart and then we have to find the nominal loop transfer function such that satisfies the boundaries and has the minimum high frequency gain. The major drawback of the QFT method is that there is no effective and useful method for finding this nominal loop transfer function. The usual approach to this problem involves loop-shaping in the Nichols chart by manipulating the poles and zeros of the nominal loop transfer function. This process now aided by recently developed computer aided design tools proceeds by trial and error and its success often depends heavily on the experience of the loop-shaper. Thus for the novice and First time QFT user, there is a genuine need for an automatic loop-shaping tool to generate a first-cut solution. In this paper, we approach the automatic QFT loop-shaping problem by using an algorithm involving Linear Programming (LP) techniques and Genetic Algorithm (GA).

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Bone Regeneration in the Extraction Socket Filled with Atelocollagen: Histological and Radiographic Study in Beagle Dogs

  • Lee, Hyeonjong;Noh, Kwantae;Lee, Deok-Won
    • Journal of Korean Dental Science
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    • v.9 no.2
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    • pp.55-62
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    • 2016
  • Purpose: Alveolar bone develops with tooth eruption and is absorbed following tooth extraction. Various ridge preservation techniques have sought to prevent ridge atrophy, with no superior technique evident. Collagen has a long history as a biocompatible material. Its usefulness and safety have been amply verified. The related compound, atelocollagen, is also safe and displays reduced antigenicity since telopeptides are not present. Materials and Methods: The current study evaluated whether the $Rapiderm^{(R)}$ atelocollagen plug (Dalim Tissen, Seoul, Korea) improves tissue healing of extraction sockets and assessed the sequential pattern of bone regeneration using histology and microcomputed tomography in six beagle dogs. To assess the change of extraction socket, hard tissues were examined 2, 4, 6, and 8 weeks after tooth extraction. Result: The experimental groups showed better bone fill with slow remodeling process compared to the control groups although there was no statistical difference between groups. Conclusion: The atelocollagen seems to have a tendency to slow bone remodeling in the early phase of healing period and maintain remodeling capacity until late phase of remodeling. Also, use of atelocollagen increased the bone-to-tissue ratio compared to healing of untreated extraction socket.

A 23.52µW / 0.7V Multi-stage Flip-flop Architecture Steered by a LECTOR-based Gated Clock

  • Bhattacharjee, Pritam;Majumder, Alak;Nath, Bipasha
    • IEIE Transactions on Smart Processing and Computing
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    • v.6 no.3
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    • pp.220-227
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    • 2017
  • Technology development is leading to the invention of more sophisticated electronics appliances that require long battery life. Therefore, saving power is a major concern in current-day scenarios. A notable source of power dissipation in sequential structures of integrated circuits is due to the continuous switching of high-frequency clock signals, which do not carry any information, and hence, their switching is eliminated by a method called clock gating. In this paper, we have incorporated a recent clock-gating style named Leakage Control Transistor (LECTOR)-based clock gating to drive a multi-stage sequential architectures, and we focus on its performance under three different process corners (fast-fast, slow-slow, typical-typical) through Monte Carlo simulation at 18 GHz clock with 90 nm technology. This gating is found to be one of the best gated approaches for multi-stage architectures in terms of total power consumption.

Verification of Vibration Test System for Geostationary Satellite (정지궤도위성 진동시험을 위한 가진 시스템 검증)

  • Im, Jong-Min;Moon, Sang-Moo;Eun, Hee-Kwang;Moon, Nam-Jin;Lee, Dong-Woo;Moon, Guee-Won
    • Aerospace Engineering and Technology
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    • v.9 no.2
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    • pp.143-152
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    • 2010
  • Development and verification of whole vibration test system was requested for developing a geostationary satellite. This satellite is enlarged significantly compared with fore-satellite in KARI. For vertical vibration test, new vertical vibration system was developed. For lateral vibration test, thermal equilibrium test was performed because of difference of thermal characteristics between test adapter and slip table. And lateral vibration system performance for overturning moment was verified by analysis and test. As the number of acquisition channels was increased, new shaker control and data acquisition system was installed. In this paper, verification process and techniques to improve test stability are introduced for the whole vibration test system.

Recent Emulsion Technology in Cosmetics (화장품용 유화 제조기술 최근동향)

  • Hwang, So-Ra;Nam, Jin-Oh;Lee, Byung-Jin;Song, Woo-Ho;Lee, Chang-Soo
    • KSBB Journal
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    • v.27 no.4
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    • pp.207-214
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    • 2012
  • Emulsions are mixture of immiscible liquids in which one is dispersed in all over the other. They have been applied to many applications including cosmetics, foods, drug delivery system (DDS), fine chemicals, and chemical separations. Especially, emulsion technology is one of the most useful technique to formulate cosmetics such as eye cream, foundation, and foam cleansing. In general, the emulsions can be generated by mechanical agitation of two immiscible fluids. However, the emulsions obtained by conventional method have limited in stability, monodispersity, and complicate process. We describe here preparation techniques of representative cosmetic emulsions such as liposome, liquid crystal emulsion, nanoemulsion, multiple emulsion, and pickering emulsion. Furthermore, various factors which can control the physical properties of each cosmetic emulsions are briefly discussed.

Local protein synthesis in neuronal axons: why and how we study

  • Kim, Eunjin;Jung, Hosung
    • BMB Reports
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    • v.48 no.3
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    • pp.139-146
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    • 2015
  • Adaptive brain function and synaptic plasticity rely on dynamic regulation of local proteome. One way for the neuron to introduce new proteins to the axon terminal is to transport those from the cell body, which had long been thought as the only source of axonal proteins. Another way, which is the topic of this review, is synthesizing proteins on site by local mRNA translation. Recent evidence indicates that the axon stores a reservoir of translationally silent mRNAs and regulates their expression solely by translational control. Different stimuli to axons, such as guidance cues, growth factors, and nerve injury, promote translation of selective mRNAs, a process required for the axon's ability to respond to these cues. One of the critical questions in the field of axonal protein synthesis is how mRNA-specific local translation is regulated by extracellular cues. Here, we review current experimental techniques that can be used to answer this question. Furthermore, we discuss how new technologies can help us understand what biological processes are regulated by axonal protein synthesis in vivo.

A Technique to Efficiently Place Sensors for Three-Dimensional Robotic Manipulation : For the Case of Stereo Cameras (로봇의 3차원 작업을 위한 효율적 센서위치의 결정기법 : 스테레오 카메라를 중심으로)

  • Do, Yong-Tae
    • Journal of Sensor Science and Technology
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    • v.8 no.1
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    • pp.80-88
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    • 1999
  • This paper deals with the position determination problem of stereo camera systems used as a sensor for 3D robotic manipulation. Stereo cameras having parallel rays of sight and been set up on the same baseline are assumed. The distance between the sensor and the space measured is determined so as to get insensitive parameters to the uncertainty of control points used for calibration and to satisfy the error condition set by considering the repeatability of the robot. The baseline width is determined by minimizing the mutual effect of 3D positional error and stereo image coordinate error. Unlike existing techniques, the technique proposed here is developed without complicated constraints and modelling process of the object to be observed. Thus, the technique of this paper is more general and its effectiveness is proved by simulation.

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Generating a Ball Sport Scene in a Virtual Environment

  • Choi, Jongin;Kim, Sookyun;Kim, Sunjeong;Kang, Shinjin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.11
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    • pp.5512-5526
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    • 2019
  • In sports video games, especially ball games, motion capture techniques are used to reproduce the ball-driven performances. The amount of motion data needed to create different situations in which athletes exchange balls is bound to increase exponentially with resolution. This paper proposes how avatars in virtual worlds can not only imitate professional athletes in ball games, but also create and edit their actions effectively. First, various ball-handling movements are recorded using motion sensors. We do not really have to control an actual ball; imitating the motions is enough. Next, motion is created by specifying what to pass the ball through, and then making motion to handle the ball in front of the motion sensor. The ball's occupant then passes the ball to the user-specified target through a motion that imitates the user's, and the process is repeated. The method proposed can be used as a convenient user interface for motion based games for players who handle balls.

Development of new agrochemicals by qnantitative structure-activity relationship (QSAR) methodology. II. The linear free energy relationship (LFER) and descriptors (정량적인 구조-활성상관(QSAR) 기법에 의한 새로운 농약의 개발 II. 자유에너지 직선관계(LFER)와 설명인자들)

  • Sung, Nack-Do
    • The Korean Journal of Pesticide Science
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    • v.6 no.4
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    • pp.231-243
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    • 2002
  • Starting with linear free energy relationships (LFER), drug design to mimic of the activated complexes at transition state, and hydrolysis mechanisms to control the potency and residual properties of pesticides were introduced and summarized for the necessity. In order to understand the searching or development of new agrochemicals by two dimensional quantitative structure-activity relationship (2D QSAR) methodology, a series of the various descriptors, steric constants, electronic constants including quantum pharmacological parameters and hydrophobic constants were classified and discussed for results of the several studied cases. In addition, the processes of development of new agrochemicals by QSAR techniques were introduced simply.

Three-dimensional finite element analysis of reinforced concrete slabs strengthened with epoxy-bonded steel plates

  • Metwally, Ibrahim M.
    • Advances in concrete construction
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    • v.2 no.2
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    • pp.91-108
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    • 2014
  • This paper presents a nonlinear finite element analysis (FEA) in order to investigate the flexural performance of one-way slabs strengthened by epoxy-bonded steel plates. Four point loading scheme is selectively chosen. A model is developed to implement the material constitutive relationships and non-linearity. Five Slabs were modeled in FEM software using ABAQUS. One slab was unstrengthened control slab and the others were strengthened with steel plates with varying the plate thickness and configuration. In order to verify the accuracy of the numerical model, a comparison was done between the experimental results available in the literature and the proposed equations by ACI 318-11 for the calculation of ultimate load capacities of strengthened slabs, the agreement has proven to be good and FEA attained accurate results compared with ACI code. A parametric study was also carried out to investigate the influence of thickness of steel plate, strength of epoxy layer and type of strengthening plate on the performance of plated slabs. Also, the practical and technical feasibility of splitting the steel plate in strengthening process has been taken into account. For practical use, the author recommended to use bonded steel plate as one unit rather than splitting it to parts, because this saves more effort and reduces the risk of execution errors as in the case of multiple bonded parts. Both techniques have nearly the same effect upon the performance of strengthened slabs.