• Title/Summary/Keyword: enumeration

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An Enumeration Algorithm for the Rolling Stock Requirement Plan (철도차량소요계획을 위한 열거알고리듬)

  • Kim Seongho;Kim Dong-Hee;Choi Tae-Sung
    • Proceedings of the KSR Conference
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    • 2004.06a
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    • pp.514-521
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    • 2004
  • A routing is the path that an actual train set follows as it moves from one train to another train in a timetable. The number of routings is equivalent to the number of trainsets required to cover the timetable. The primary factors of rolling stock requirement plan include evaluating the minimum number of routings. This can be formulated as a set partitioning problem and solved using enumeration method or column generation method. In this paper we presents an enumeration algorithm which is useful to implement the enumeration method for the rolling stock requirement plan.

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An Enumeration Algorithm for Generating the Candidate Routings in a Set Partitioning Problem Approach to the Rolling Stock Requirement Plan (철도차량소요계획에 대한 집합분할문제 접근에서 후보운용생성을 위한 열거알고리즘)

  • 김성호;김동희;최태성
    • Journal of the Korean Society for Railway
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    • v.7 no.4
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    • pp.326-331
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    • 2004
  • A routing is the path that an actual trainset follows as it moves from one train to another train in a timetable. The number of routings is equivalent to the number of trainsets required to cover the timetable. The primary factors of rolling stock requirement plan include evaluating the minimum number of routings. This can be formulated as a set partitioning problem and solved using enumeration method or column generation method. In this paper we presents an enumeration algorithm which is useful to implement the enumeration method for the rolling stock requirement plan.

Structural Classification and Enumeration of Pin-Jointed Kinematic Chains (핀 조인트로 구성된 기구학적 연쇄들의 구조적 분류 및 열거)

  • 이종기;신재균
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.3
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    • pp.565-572
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    • 1994
  • A method for the classification of kinematic chains according to the similarity in their structures is proposed. Classifcation code is defined from the contracted graph of the kinematic chain. This method of classifying kinematic chains can be effectively used for the systematic enumeration of structurally distinct kinematic chains given the number of links and degrees of freedom of the kinematic chains. Two separate steps for the enumeration are developed in the study. The first step is to generated all the possible classification codes and the next step is to generate individual kinematic chains belonging to each classification code generated. Using this two step procedure, kinematic chains up to 12 links are successfully enumerated in the present study. It is concluded that the two step method can be efficiently used for the type synthesis of mechanisms.

Stydies on the Selective Screening Method of Bifidobacteria Used in Yoghurt (호상 요구르트 제품에 이용되는 Bifidobacteria 의 선택적 검출 방법)

  • 박희경;허태련
    • Microbiology and Biotechnology Letters
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    • v.23 no.2
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    • pp.214-219
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    • 1995
  • In fermentation of dairy products, bifidobacteria is used in conjunction with other lactic acid bacteria, such as L. acidophilus, L. bulgaricus and S. thermophilus, rendering the enumeration of bifidobacteria difficult. In order to develop optimum conditions for selective enumeration of bifidobacteria, we examined MIC of several antibiotics against various bifidobacteria and other lactic acid bacteria. The growth of L. acidophilus, L. bulgaricus and S. thermophilus were inhibited by lithium chloride at the concentration of less than 4 mg/ml, whereas growth inhibition of bifidobacteria occurred at concentrations over 6-10 mg/ml. Tetracycline and chloramphenicol were also found to selectively inhibit growth of other lactic acid bacteria at the concentration of 1-3 $\mu$g/ml. Addition of 6 mg/ml lithium chloride, 1 $\mu$g/ml, tetracycline or 3 $\mu$g/ml chloramphenicol to medium was found to be optimal for selective enumeration of bifidobacteria. By using these three inhibitory chemicals in the TPY medium, higher number of bifidobacteria were selectively isolated than with NPNL agar and LP agar.

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Source Enumeration Method using Eigenvalue Gap Ratio and Performance Comparison in Rayleigh Fading (Eigenvalue Gap의 Ratio를 이용한 신호 개수 추정 방법 및 Rayleigh Fading 환경에서의 신호 개수 추정 성능 비교)

  • Kim, Taeyoung;Lee, Yunseong;Park, Chanhong;Choi, Yeongyoon;Kim, Kiseon;Lee, Dongkeun;Lee, Myung-Sik;Kang, Hyunjin
    • Journal of the Korea Institute of Military Science and Technology
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    • v.24 no.5
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    • pp.492-502
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    • 2021
  • In electronic warfare, source enumeration and direction-of-arrival estimation are important. The source enumeration method based on eigenvalues of covariance matrix from received is one of the most used methods. However, there are some drawbacks such as accuracy less than 100 % at high SNR, poor performance at low SNR and reduction of maximum number of estimating sources. We suggested new method based on eigenvalues gaps, which is named AREG(Accumulated Ratio of Eigenvalues Gaps). Meanwhile, FGML(Fast Gridless Maximum Likelihood) which reconstructs the covariance matrix was suggested by Wu et al., and it improves performance of the existing source enumeration methods without modification of algorithms. In this paper, first, we combine AREG with FGML to improve the performance. Second, we compare the performance of source enumeration and direction-of-arrival estimation methods in Rayleigh fading. Third, we suggest new method named REG(Ratio of Eigenvalues Gaps) to reduce performance degradation in Rayleigh Fading environment of AREG.

COUNTING SELF-CONVERSE ORIENTED TREES

  • Choi, Su-Jeong;Lee, Chang-Woo
    • Communications of the Korean Mathematical Society
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    • v.16 no.1
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    • pp.67-73
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    • 2001
  • We classify self-converse oriented trees into two types, namely, bicentral self-converse oriented trees and central ones, according to their centers and characterize these tow types. Using characterizations and Polya enumeration theorem, we derive the ordinary generating function for self-converse oriented trees.

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Freezing Seawater for the Long-term Storage of Bacterial Cells for Microscopic Enumeration

  • Hyun, Jung-Ho;Yang, Eun-Jin
    • Journal of Microbiology
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    • v.41 no.3
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    • pp.262-265
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    • 2003
  • Although enumerating bacterial cells is a fundamental step in understanding microbial ecosystems in marine environments, substantial decrease in bacterial counts with increasing sample storage time hampers the accurate estimation of bacterial biomass. We compared the variations in bacterial cell numbers caused by freezing and thawing of sample bottles or slides. Bacterial counts of seawater samples frozen only once in a sampling bottle yielded approximately 95% of the original numbers after 90 days, whereas 80% of the original count was obtained for samples prepared on slides. Only 67% and 58% of the original counts were recovered in samples repeatedly frozen and thawed in bottles or on slides, respectively. The results indicated that freezing a seawater sample in a bottle increased the consistency of the epifluorescence microscopic enumeration of bacterial cells.

Phase Offset Enumeration Method with Error Detection and Its Application to Synchronization of PN Sequences

  • Song Young-Joan
    • Journal of electromagnetic engineering and science
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    • v.5 no.1
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    • pp.26-30
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    • 2005
  • It is important to know phase offsets of PN(Pseudo Noise) sequences in spread spectrum communications since the acquisition is equivalent to making a phase offset between a receiving PN sequence and a PN sequence of local PN generator be identical. In this paper, a phase offset enumeration method for PN sequences with error detection, and its application to the synchronization are proposed. The phase offset enumeration for an n-tuple PN sequence and its error detection are performed when one period of the sequence is received. Once the phase offset of the receiving sequence is calculated, we can easily accomplish the synchronization by initializing shift registers of a local PN generator according to the phase offset value. The mean acquisition time performance of the proposed scheme was derived analytically. Since this synchronization scheme can be realized by using simple circuit and acquires very rapid acquisition in high SNR but shows performance degradation in low SNR, it can be especially useful in indoor and office environments.

Enumeration of Vibrio vulnificus in Natural Samples by Colony Blot Hybridization

  • Lee, Jeong-Hyun;Lee, Kyu-Ho;Choi, Sang-Ho
    • Journal of Microbiology and Biotechnology
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    • v.11 no.2
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    • pp.302-309
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    • 2001
  • Colony blot hybridization using a VVHP DNA probe derived from the sequence of the hemolysin gene, vvhA, was specific in identifying all V. vulnificus strains, thereby, eliminating the need for any additional phenotypic identification. The colony blot hybridization procedure revealed a sensitivity and broad applicability sufficient for the direct enumeration of V. vulnificus in various natural samples, without the use of enrichment or culturing on selective medis. V. vulnificus was detected in all natural samples collected during August and May at concentrations ranging from $2.1{\times}10^1\;to\;4.0{\times}10^3$ organisms per ml. However, during November and February, when the mean temperatures of the seawater were $12^{\circ}C$ and $5^{\circ}C$, respectively, V. vulnificus was not detected in any natural samples.

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