• Title/Summary/Keyword: Sequential

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Solving a Nonlinear Inverse Convection Problem Using the Sequential Gradient Method

  • Lee, Woo-Il;Lee, Joon-Sik
    • Journal of Mechanical Science and Technology
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    • v.16 no.5
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    • pp.710-719
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    • 2002
  • This study investigates a nonlinear inverse convection problem for a laminar-forced convective flow between two parallel plates. The upper plate is exposed to unknown heat flux while the lower plate is insulated. The unknown heat flux is determined using temperature measured on the lower plate. The thermophysical properties of the fluid are temperature dependent, which renders the problem nonlinear. The sequential gradient method is applied to this nonlinear inverse problem in order to solve the problem efficiently. The function specification method is incorporated to stabilize the sequential estimation. The corresponding adjoint formalism is provided. Accuracy and stability have been examined for the proposed method with test cases. The tendency of deterministic error is investigated for several parameters. Stable solutions are achieved eve]1 with severely impaired measurement data.

Time Optimal Performance of a Varying-Time Sharing Sequential Paired Thrusting Logic (순차적 가변시간할당 추력방식 최적성능 분석)

  • Oh, Hwa-Suk;Lee, Byung-Hoon;Lee, Bong-Un
    • Journal of Institute of Control, Robotics and Systems
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    • v.11 no.3
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    • pp.254-261
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    • 2005
  • Time-optimal performances are analyzed in the sense of inner loop. A varying-time sharing thrusting logic is suggested as a new sequential paired thrusting logic for fast maneuvers of satellites with coupled thruster configuration. Its time-optimal maneuvering performance is compared with two conventional thrusting logics: separate thrusting logic and constant-time sharing sequential paired thrusting logic. It is found that the newly suggested varying-time sharing thrusting logic can be easily implemented by adjusting the conventional constant-time logic with its thrust on-time, while it can reduce the maneuvering time enormously as much as the separate thrusting logic. The performance of the logic is simulated on the agile maneuvering spacecraft model KOMPSAT-II.

A Study on the Internet Control and Monitoring System using an Embedded System (임베디드 시스템을 이용한 인터넷 제어감시 시스템에 관한 연구)

  • Haeng-Choon Chun
    • Journal of Advanced Marine Engineering and Technology
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    • v.28 no.5
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    • pp.811-817
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    • 2004
  • Recently embedded systems are widely used in various industrial fields as supervisory controller because they have many merits. One of merits seems to be that operating environment of embedded system is the same as development environment using PC. That makes developing and manufacturing period shorten and also proper time to market Most of all machinery have sequential control system for their maneuvering which is composed of relays. contacts. timers. etc. In this paper. software sequential control system is proposed to be able to replace hardware sequential control system by using embedded system A lot of merits by the software sequential control system can be expected in the respect of economic reproduction, intelligent technologies and utilities, And porting of LINUX operating system to embedded system is carried out and device drivers and interface boards for LINUX 05 are designed for controlling air compressor by software Internet remote control and monitoring system of air compressor is implemented with Java script and CGI for these purposes. The experiment for operating air compressor system is taken through internet networks. The results show that developed system can be used for real plant.

Synthesis of Norbornene Block Copolymers Containing Polyhedral Oligomeric Silsesquioxane by Sequential Ring-Opening Metathesis Polymerization

  • Kwon Young-Hwan;Kim Kyung-Hoe
    • Macromolecular Research
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    • v.14 no.4
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    • pp.424-429
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    • 2006
  • The synthesis of a series of poly(POSS-NBE-b-MTD) copolymers was successfully accomplished, taking advantage of sequential, ring-opening, metathesis block copolymerization using $RuCl_2(=CHPh)(PCy_3)_2$ catalyst. By using cyclopentyl-POSS-norbornene (POSS-NBE) monomer as the first block in the block copolymer, living poly(POSS-NBE) with controlled molecular weight and narrow molecular weight distribution was produced. Then, poly(POSS-NBE-b-MTD) copolymers were successfully prepared, in which sequential monomer addition of methyltetracyclododecene (MTD) to the living poly(POSS-NBE) chain ends was utilized to achieve quantitative crossover efficiency. Characterization by $^1H$ NMR spectroscopy and GPC confirmed the high definition and structural integrity of the poly(PO$S-NBE-b-MTD) copolymers. Thermal properties-and morphologies of the POSS-containing block copolymer nanocomposites were also investigated by using thermogravimetric analysis (TGA), transmission electron microscopy (TEM), and wide-angle X-ray scattering (WAXS).

Two Sequential Wilcoxon Tests for Scale Alternatives

  • Mishra, Prafulla-Chandra
    • Journal of the Korean Statistical Society
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    • v.30 no.4
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    • pp.679-691
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    • 2001
  • Two truncated sequential tests are developed for the two-sample scale problem based on the usual Wilcoxon rank-sum statistic for two different dispersion indices - absolute median deviations, when the medians of the two populations X and Y are equal or known and sums of squared mean deviations, when the medians are either unknown or unequal. The first test is briefly called SWAMD test and the second SWSMD test. For the SWAMD test, the percentile points for both the one-sided and two-sided alternatives, (equation omitted) have been found by Wiener approximation and their values computed for a range of values of a and N; analytical expression for the power function has been derived through Wiener process and its performance studied for various sequential designs for exponential distribution. This test has been illustrated by a numerical example. All the results of the SWAMD test, being directly applicable to the SWSMD test, are not dealt with separately Both the tests are compared and their suitable applications indicated.

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An Overview of Group Sequential Procedures (집단축차검정법들에 관한 고찰)

  • Jae Won Lee
    • The Korean Journal of Applied Statistics
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    • v.7 no.2
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    • pp.35-51
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    • 1994
  • For ethical and economic reasons, clinicla trials must be repeatedly monitored for evidence of treatment benefit or harm. Repeated testing at conventional critical values can substantially inflate the overal type I error rate. To maintain acceptable levels, group sequential procedures have been developed for clinical trials. This article gives a brief overview of the group sequential procedures.

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Computer Aided Design of Sequential Logic Circuits (Case of Synchronous Sequential Logic Circuits) (컴퓨터를 이용한 순차 논리 회로의 설계 (동기식 순차 논리 회로의 경우))

  • 김경식;조동섭;황희영
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.33 no.4
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    • pp.134-139
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    • 1984
  • This paper presents the computer program to design the synchronous sequential logic circuit. The computer program uses the MASK method to get the circuit of optimal cost. The computer program takes as an input, the minimal reduced state transition table where each state has its internal code. As an output,the optimal design of synchronous sequential logic circuit is generated for each flipflop type of JK,T,D, and RS respectively. And these circuits for 4 flipflop types are evaluated and sorted in ascending order of their costs, so that the user can select the proper flipflop type and its circuit. Furthermore,the proposed computer program may be applied to state assignment with its facility of cost evaluation.

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Sequential pattern load modeling and warning-system plan in modular falsework

  • Peng, Jui-Lin;Wu, Cheng-Lung;Chan, Siu-Lai
    • Structural Engineering and Mechanics
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    • v.16 no.4
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    • pp.441-468
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    • 2003
  • This paper investigates the structural behavior of modular falsework system under sequential pattern loads. Based on the studies of 25 construction sites, the pattern load sequence modeling is defined as models R (rectangle), L and U. The study focuses on the system critical loads, regions of largest reaction forces, discrepancy between the pattern load and the uniform load, and the warning-system plan. The analysis results show that the critical loads of modular falsework systems with sequential pattern loads are very close to those with the uniform load used in design. The regions of largest reaction forces are smaller than those calculated by the uniform load. However, the regions of largest reaction forces of three models under sequential pattern loads can be considered as the crucial positions of warning-system based on the measured index of loading. The positions of the sensors for the warning-system for these three different models are not identical.

Finite Element Elasto-plastic Analysis of a Full Tension Levelling Process using Sequential Unit Models (순차 단순모델을 이용한 전체 인장교정 공정의 탄소성 유한요소해석)

  • Lee H. W.;Huh H.;Park S. R.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2001.05a
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    • pp.201-204
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    • 2001
  • The tension levelling process is performed to elongate the strip plastically in combination of tensile and bending strain so that all longitudinal fibers in the strip have an approximately equal amount of length and undesirable strip shapes are corrected to the flat shape. This paper is concerned with a simulation of the tension levelling process based on the analysis of the unit model for the tension leveller. Analysis technique such as the sequential analysis of the nit model is suggested and verified with the assembly analysis of the unit model for the effective and economic analysis of the full set of the tension leveller. Analysis of the full tension levelling process using sequential unit models is carried out and provides the effect of the intermesh and optimum amount of the intermesh in tension levelling process.

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Otemachi(大手町) Sequential Urban Redevelopment Project

  • Itoh, Toshio
    • Land and Housing Review
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    • v.8 no.2
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    • pp.83-89
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    • 2017
  • Otemachi(大手町) is the region where it plays a pivotal role in Japanese economy as representative head offices of companies including financial insurance, general trading, information and communication newspaper media are concentrated. However, regenerating the entire region from worn-out infrastructures of buildings and city into the fresh and vibrant foothold in international business was the problem to be solved. In this situation, was examined on the basis of administrative agencies and relevant enterprises to reconstruct office buildings in phases without ceasing business functions and activities by utilizing the large-scale vacant land occurred from the relocation of the national public institutions. The independent administrative institution 'Urban Renaissance Agency(UR)' has completed the examination of industrialization and participation request for the commencement of the project. In this article, The overview of , the new form of project promoted and cooperated by officials and people, is introduced by UR (Urban Renaissance Agency) reorganizing the land exchange and infrastructure through the land readjustment project, and at the same time, procuring capital and building office buildings in solidarity with private development enterprises and financial institutions.