• Title/Summary/Keyword: bound

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Optimization Algorithms for a Two-Machine Permutation Flowshop with Limited Waiting Times Constraint and Ready Times of Jobs

  • Choi, Seong-Woo
    • Journal of Information Technology Applications and Management
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    • v.22 no.2
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    • pp.1-17
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    • 2015
  • In this research, we develop and suggest branch and bound algorithms for a two-machine permutation flowshop scheduling problem with the objective of minimizing makespan. In this scheduling problem, after each job is operated on the machine 1 (first machine), the job has to start its second operation on machine 2 (second machine) within its corresponding limited waiting time. In addition, each job has its corresponding ready time at the machine 1. For this scheduling problem, we develop various dominance properties and three lower bounding schemes, which are used for the suggested branch and bound algorithm. In the results of computational tests, the branch and bound algorithms with dominance properties and lower bounding schemes, which are suggested in this paper, can give optimal solution within shorter CPU times than the branch and bound algorithms without those. Therefore, we can say that the suggested dominance properties and lower bounding schemes are efficient.

Sliding Mode Control Using the Lower Bound of Control Gain (제어이득의 하한을 이용한 새로운 슬라이딩 모드제어)

  • 유병국
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.9
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    • pp.664-668
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    • 2003
  • A new sliding mode control method based on the lower bound of control gain is presented. Although the magnitube of the proposed control input is larger than that of the conventional control input using both lower and upper bounds, the positive-negative exchanging chattering is reduced and reaching mode is shorter. Because the proposed scheme needs only the lower bound of control gain, it is applicable to the system whose upper bound of control gain is doubtful to determine such as the control gain depends on the system states. It is proved that the proposed control method guarantees the sliding condition. The analysis of differences between the conventional method and the proposed method is given. The validity of the proposed control strategy is shown through a 2nd-order nonlinear system example.

Free and Glycosidically Bound Volatile Components in Tobacco Leaves(Nicotiana tabacum L.) (잎담배중 유리 및 Glycoside형태로 존재하는 휘발성 향기성분)

  • 김영회;나도영;김옥찬;서철원;김용태
    • Journal of the Korean Society of Tobacco Science
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    • v.14 no.1
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    • pp.79-86
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    • 1992
  • Free and glycosidically bound volatiles from three green tobacco leaves(NC 82, KF 109 and Br-21) were separated by nonionic resin Amberlite XAD-2 adsorption column chromatography and election by selective solvents. Aglycones from the glycosidically bound fractions were released by enzymatic hydrolysis with almond B-glucosidase. A total of 20 components identified from free and glycosidically bound fractions, the major components were benzaldehyde, benzyl alcohol, 2-phenylethyl alcohol, 3-oxo- -ionol, 3-hydroxy-B-ionone, 3-oxo-7, 8-dihydro-n-ionol and scopoletin. Six Cl.B norisoprenoids identified in this study, which have been described to possess a characteristic tobacco aroma-enhancing effect, were not presented in free forms but rather bound glycosidic forms.

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Upper Bound Analysis of Dynamic Buckling Phenomenon of Circular Tubes Considering Strain Rate Effect (변형률 속도를 고려한 원형 튜브의 동적 좌굴 현상의 상계 해석에 관한 연구)

  • Park, Chung-Hee;Ko, Youn-Ki;Huh, Hoon
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.711-716
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    • 2008
  • A circular tube undergoes bucking behavior when it is subjected to axial loading. An upper bound analysis can be an attractive approach to predict the buckling load and energy absorption efficiently. The upper bound analysis obtains the load or energy absorption by means of assumption of the kinematically admissible velocity fields. In order to obtain an accurate solution, kinematically admissible velocity fields should be defined by considering many factors such as geometrical parameters, dynamic effect, etc. In this study, experiments and finite element analyses are carried out for circular tubes with various dimensions and loading conditions. As a result, the kinematically admissible velocity field is newly proposed in order to consider various dimensions and the strain rate effect of material. The upper bound analysis with the suggested velocity field accurately estimates the mean load and energy absorption obtained from results of experiment and finite element analysis.

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THE LINEAR DISCREPANCY OF A PRODUCT OF TWO POSETS

  • Cheong, Minseok
    • Bulletin of the Korean Mathematical Society
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    • v.54 no.3
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    • pp.1081-1094
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    • 2017
  • For a poset $P=(X,{\leq}_P)$, the linear discrepancy of P is the minimum value of maximal differences of all incomparable elements for all possible labelings. In this paper, we find a lower bound and an upper bound of the linear discrepancy of a product of two posets. In order to give a lower bound, we use the known result, $ld({\mathbf{m}}{\times}{\mathbf{n}})={\lceil}{\frac{mn}{2}}{\rceil}-2$. Next, we use Dilworth's chain decomposition to obtain an upper bound of the linear discrepancy of a product of a poset and a chain. Finally, we give an example touching this upper bound.

A study on the process of tube end spinning by the upper bound method and the finite element method (상계해법과 유한요소법을 이용한 스피닝공정 해석에 관한 연구)

  • 김전형;홍성인;이정환;이영선
    • Transactions of Materials Processing
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    • v.6 no.6
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    • pp.517-526
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    • 1997
  • The purpose of this study is to investigate changes in the wall thickness of tube sinking and working forces by the upper bound method and ABAQUS code. The independent variables are ; workpiece material, original wall thickness of tube, die angle, friction, and reduction of diameter. The results indicate that these five variables are factors of the increase in wall-thickness and working forces. Three variables, a inner tube wall angle and two angles of the velocity discontinuous surfaces, are optimized in this proposed velocity field by the upper bound method. In this method, we can estimate the working forces and final tube thicknesses similar to actual forming process. Optimum process variables which are obtained by upper bound method are used in ABAQUS pre-model.

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Binding of Sanjoinine-A (Frangufoline) to Calmodulin

  • Han, Yong-Nam;Kim, Geum-Yi;Hwang, Keum-Hee;Han, Byung-Hoon
    • Archives of Pharmacal Research
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    • v.16 no.4
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    • pp.289-294
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    • 1993
  • A binding protein of radio-labeled sanjoinine-A (fangufoline) in rat brain cytoplasm was investigated, using an equilibrium dialysis technique. The labeled agent was bound to the cytosol fraction with two distinctly different types of sets in calclum ion-dependent manner. The bound protein was identified as calmodulin by dgel filtration of the sanjoinine-A bound cytosol fraction on a Sephadex G-75 column. Calmodulin was bound to sanjoinine-A bound at two sets of binding sites in the calculated as two at high affinity sites $(Kd=1.1\;mu{M)}$ and four at low affinity sites $(Kd=3.1\;\mu{M)}$.

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Peptide Synthesis with Polymer Bound Active Ester. I. Rapid Synthesis of Peptides Using Polymer Bound 1-Phenyl-3-methyl-4-oximinopyrazole

  • Lee, Ki-Wha;Lee, Yoon-Sik
    • Bulletin of the Korean Chemical Society
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    • v.10 no.4
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    • pp.331-335
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    • 1989
  • Polymer bound 1-phenyl-3-methyl-4-oximinopyrazoles were prepared through a series of chemical modifications of Merrifield's resin (chloromethylpolystyrene-$1{\%}$ DVB-copolymer). Several polymer active esters of N-blocked amino acids were prepared from the polymer bound 1-phenyl-3-methyl-4-oximinopyrazoles. Polymer bound active esters were found to be highly reactive in N-acylation reaction. The resins were tested for the preparation of several dipeptides. The peptides were obtained in high yields within 10 minutes and the progress of the reactions could be easily followed up by the color change of the resin. The resulting peptides were characterized by NMR and other physical methods.

Phyllomanganate Minerals: Their Synthesis and Crystal Chemistry (층상구조형 산화망간광물의 합성과 그 결정화학적 특성)

  • 최헌수;김수진
    • Journal of the Mineralogical Society of Korea
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    • v.10 no.2
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    • pp.82-96
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    • 1997
  • Buserties are known to have layer structures with variable C dimension which depended on the nature interlayer catious and contents of water molecular between edge-sharing [MnO6] octabedral layers. Na-, Ca-, Mg-, and Zn-buserties were synthesized in the laboratory and studied for to know the structural states of water molecules and the role of catious in the buserite structures. With lowering the relative humidity(RH), Ca-buserite begins to dehydrate at 27% RH and proceeds further very slowly. Mg- and Zn- buserite also slow dehydration above 2% RH. With gradual ineveasing temperature Ca- and Zn-buserite show abrupt shifting of 10$\AA$ peak (10$\AA$-phare) toward 7$\AA$ peak. All of 7$\AA$-phare are further dehydrated to 5$\AA$-phare by further increasing temperature. It suggests that interlayer catious play a crucial role in the dehydration behavious of buserites. Simulation of one-dimensional X-ray diffraction patterns of buserties show that buserites have three layers of water molecules of different types: the very loosely bound and tightly bend waters, instead of two layers that was regarded by previous authers. The very loosely bound water is sited I open space of the interlayer, the loosely bound water is bound on the tightly bound water by hydrogen bond, and the tightly bond water in coodinately bound on the interlayer catious.

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A Flexible Branch and Bound Method for the Job Shop Scheduling Problem

  • Morikawa, Katsumi;Takahashi, Katsuhiko
    • Industrial Engineering and Management Systems
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    • v.8 no.4
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    • pp.239-246
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    • 2009
  • This paper deals with the makespan minimization problem of job shops. The problem is known as one of hard problems to optimize, and therefore, many heuristic methods have been proposed by many researchers. The aim of this study is also to propose a heuristic scheduling method for the problem. However, the difference between the proposed method and many other heuristics is that the proposed method is based on depth-first branch and bound, and thus it is possible to find an optimal solution at least in principle. To accelerate the search, when a node is judged hopeless in the search tree, the proposed flexible branch and bound method can indicate a higher backtracking node. The unexplored nodes are stored and may be explored later to realize the strict optimization. Two methods are proposed to generate the backtracking point based on the critical path of the current best feasible schedule, and the minimum lower bound for the makespan in the unexplored sub-problems. Schedules are generated based on Giffler and Thompson's active schedule generation algorithm. Acceleration of the search by the flexible branch and bound is confirmed by numerical experiment.