• Title/Summary/Keyword: separability

Search Result 154, Processing Time 0.021 seconds

CYCLIC SUBGROUP SEPARABILITY OF HNN EXTENSIONS

  • Kim, Goansu
    • Bulletin of the Korean Mathematical Society
    • /
    • v.30 no.2
    • /
    • pp.285-293
    • /
    • 1993
  • In [4], Baumslag and Tretkoff proved a residual finiteness criterion for HNN extensions (Theorem 1.2, below). This result has been used extensively in the study of the residual finiteness of HNN extensions. Note that every one-relator group can be embedded in a one-relator group whose relator has zero exponent sum on a generator, and the latter group can be considered as an HNN extension. Hence the properties of an HNN extension play an important role in the study of one-relator groups [3], [2]. In this paper we prove a criterion for HNN extensions to be .pi.$_{c}$(Theorem 2.2). Moreover, we can prove that certain one-relator groups, known to be residually finite, are actually .pi.$_{c}$. It was known by Mostowski [10] that the word problem is solvable for finitely presented, residually finite groups. In the same way, the power problem is solvable for finitely presented .pi.$_{c}$ groups. Another application of subgroup separability with respect to special subgroups was mentioned by Thurston [12, Problem 15].m 15].

  • PDF

Feature Generation Method for Low-Resolution Face Recognition (저해상도 얼굴 영상의 인식을 위한 특징 생성 방법)

  • Choi, Sang-Il
    • Journal of Korea Multimedia Society
    • /
    • v.18 no.9
    • /
    • pp.1039-1046
    • /
    • 2015
  • We propose a feature generation method for low-resolution face recognition. For this, we first generate new features from the input features (pixels) of a low-resolution face image by adding the higher-order terms. Then, we evaluate the separability of both of the original input features and new features by computing the discriminant distance of each feature. Finally, new data sample used for recognition consists of the features with high separability. The experimental results for the FERET, CMU-PIE and Yale B databases show that the proposed method gives good recognition performance for low-resolution face images compared with other method.

Structural Quality Defect Discrimination Enhancement using Vertical Energy-based Wavelet Feature Generation (구조물의 품질 결함 변별력 증대를 위한 수직 에너지 기반의 웨이블릿 Feature 생성)

  • Kim, Joon-Seok;Jung, Uk
    • Journal of Korean Society for Quality Management
    • /
    • v.36 no.2
    • /
    • pp.36-44
    • /
    • 2008
  • In this paper a novel feature extraction and selection is carried out in order to improve the discriminating capability between healthy and damaged structure using vibration signals. Although many feature extraction and selection algorithms have been proposed for vibration signals, most proposed approaches don't consider the discriminating ability of features since they are usually in unsupervised manner. We proposed a novel feature extraction and selection algorithm selecting few wavelet coefficients with higher class discriminating capability for damage detection and class visualization. We applied three class separability measures to evaluate the features, i.e. T test statistics, divergence, and Bhattacharyya distance. Experiments with vibration signals from truss structure demonstrate that class separabilities are significantly enhanced using our proposed algorithm compared to other two algorithms with original time-based features and Fourier-based ones.

A Study On ID-Based Group Signature (신원 정보 기반 그룹 서명)

  • Kim, Dae-Youb;Ju, Hak-Soo
    • The KIPS Transactions:PartC
    • /
    • v.12C no.4 s.100
    • /
    • pp.489-494
    • /
    • 2005
  • In 2002, Shundong Xia proposed a new ID-based group signature scheme with strong separability. The nature of a strong separability is to divide group manager's role into a membership manager and a revocation manager Jianhong et al showed that the scheme was not coalition-resistant. In this letter, we first propose two new attacks, forgery and link attacks, for Xia-You's scheme. We also propose a new ID-based group signature scheme that Is resistant to coalition, forgery and link attacks

Translation of Separable Systems into the Lambda Calculus (분리 시스템의 람다 계산법으로의 변환)

  • Byun, Sug-Woo
    • Journal of KIISE:Computer Systems and Theory
    • /
    • v.35 no.4
    • /
    • pp.178-185
    • /
    • 2008
  • This research presents an translation technique of encoding rewrite rules with patterns into the lambda calculus. We show, following the theory of Böhm separability, rewrite rules with distinctive patterns, called separable systems, can be translated into the lambda calculus. Moreover, according to the property of Böhm equivalence classes, we can also encode rewrite systems with default rules, which allows to interpret some of 'undefined' terms of TRSs as an identified lambda term.

Line Balanced Assembly Sequence Generation Based on a Verification of Disassemblability and Work Time (분해도 및 작업시간 산정을 통한 균형잡힌 조립공정계획에 관한 연구)

  • Shin, Chul-Kyun
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.24 no.7 s.196
    • /
    • pp.39-48
    • /
    • 2007
  • This paper presents a method of a line balanced assembly sequence generation based on the verification of a disassemblability and a work time. To derive the disassemblability for a part to be disassembled, first we inference collision free assembly directions by extracting separable directions fur the part. And we determine the disassemblability defined by the separability and stability cost. The separability cost represents a facility of the part disassembly operation, and the stability cost which represents a degree of the stability for the base assembly motion. Based upon the results, we propose a new approach of evaluating work time using neural networks. The proposed assembly sequence generation provides an effective means of solving the line balancing problem and gives a design guidance of planning assembly lay-out in flexible manufacturing application. Example study is given to illustrate the concepts and procedure of the proposed schemes.

Kinematic Structures of Manipulators (매니퓰레이터의 운동학적 구조)

  • 황원걸
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.10 no.6
    • /
    • pp.959-965
    • /
    • 1986
  • 본 논문에서는 모듀울 로봇은 공장 자동화를 달성하기 위한 경제적인 방법으 로 기대되고 있다. 모듀울 로봇을 구성하는 모듀울을 개발 설계하기 위해서는 먼저 유용한 로봇을 기본 구조를 연구하여야 한다. 일반적으로 로봇의 처음 3개의 관절은 로봇 손의 위치를 결정하는 데 쓰이고 나머지 관절은 로(positional maneuverability matrix)과 방향기동행열로 구성됨음을 보이고, 가분성(separability)의 조건을 제시하 였다.또한 희전관절이나 미끄름관절로 이루어진 3자유도 로봇 팔의 3차원 공간에서 의 기본형태는 12개임을 밝히고, 3자유도 손목이 3개 방향을 완전히 조정할 수 있기 위해서는 3개의 회전관절축이 서로 직교하여야 함을 보였다.

Automatic Work Time Evaluation Based on a Verification of Disassemblability and Assembly Configuration (분해도 및 조립형상 정보를 이용한 작업시간 산정에 관한 연구)

  • Shin, Chul Kyun
    • Journal of Korean Institute of Industrial Engineers
    • /
    • v.33 no.3
    • /
    • pp.355-363
    • /
    • 2007
  • This paper presents a method of an automatic work time evaluation based on the verification of a disassemblability and assembly configuration. Even though a work time evaluation is an important field of concern for planning assembly lay-out, there are some limitations using cumbersome user query or approximated work time data without considering assembly condition. To overcome such restriction, this paper presents a method to mathematically verify assembly conditions based on the disassemblability, which is defined by the separability and stability cost. The separability cost represents a facility of the part disassembly operation, and the stability cost which represents a degree of the stability for the base assembly motion. Based upon the results, we propose a new approach of evaluating work time using neural networks. The proposed method provides an effective means of solving the work time evaluation problem and gives a design guidance of planning assembly lay-out in flexible manufacturing application. Example study is given to illustrate the concepts and procedure of the proposed schemes.

Party Autonomy in Arbitration Agreement: The U.S. Laws (중재합의의 당사자자치에 관한 미국계약법상 해석)

  • Ha, Choong-Lyong
    • Journal of Arbitration Studies
    • /
    • v.29 no.2
    • /
    • pp.89-105
    • /
    • 2019
  • This paper reviews and analyzes the U.S. cases and statutes on the issue of party autonomy in arbitration agreement. Arbitration agreement has been interpreted somewhat differently from general contracts because its legal characteristics are not purely contractual by nature. For example, some legal scholars insist that an arbitration contract is more about an agreement on a process of dispute resolution than a creation of rights and obligations to avoid litigation. Party autonomy was discussed in diverse legal perspectives including contract of adhesion, VKI principle, and separability of arbitration clause. These three legal perspectives are discussed to set the legal relationship between party autonomy and protection of consumers in consumer arbitration. In addition, it was discussed how legal defects in the formation of an arbitration contract can influence the party autonomy. The legal defects that were discussed to analyze the relationship between arbitration agreement and party autonomy included misrepresentation, fraud, mistake, duress, and undue influence.

Analysis of the U.S. Federal Courts' Separability Doctrines for Arbitration Clause Entered Into by the Mentally Incapacitated (정신적 무능력자가 체결한 중재약정에 관한 미국 연방법원의 분리가능성 법리의 분석)

  • Shin, Seungnam
    • Journal of Arbitration Studies
    • /
    • v.30 no.1
    • /
    • pp.39-66
    • /
    • 2020
  • Under the doctrine of separability, if the party did not specifically challenge the validity of the arbitration clause, then it is presumed valid, and arbitrators would still have authority to adjudicate disputes within the scope of the arbitration clause. Further, the Primerica and Spahr decisions address whether a court or an arbitrator should adjudicate a claim that a contract containing an arbitration clause is void ab initio due to mental incapacity. If the arbitration agreement is separable, as was found in Primerica, then the "making" of the agreement is not at issue when the challenge is directed at the entire contract and arbitrators may exercise authority. If an arbitration provision is not separable from the underlying contract, as in Spahr, a defense of mental incapacity necessarily goes against both the entire contract and the arbitration agreement, so the "making" of the agreement to arbitrate is at issue, and the claim is for courts to decide. Although no bright line rule can be established to deal with challenges of lack of mental capacity to an arbitration agreement, the rule in Prima Paint should not be extended to this defense. Extending the rule in Prima Paint would force an individual with a mental incapacity to elect between challenging the entire contract and challenging arbitration. Accordingly, there should be a special set of rules outside of the context of Prima Paint to address the situation of status-based defenses, specifically mental capacity defenses, to contracts containing arbitration provisions.