• Title/Summary/Keyword: formal method

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Algebraic Formal Specification and Formal Validation of the Standard and an Implementation of the OSPF Protocol (OSPF Protocol 표준 및 구현의 대수 정형적 명세 및 정형적 검증)

  • 박재현
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.3B
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    • pp.360-374
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    • 2004
  • The OSPF protocol is the most widely used Interior Gateway Routing Protocol. Therefore, for the reliability of behavior of gigabit swiching routers, it is essential to guarantee the interoperability and the safety of the OSPF protocol. In this paper, we analyze the standard document of the OSPF protocol, so that we provide a formal specification that specifies the protocol behaviors by detailed design level using the algebraic formal method. By referring available source codes of the OSPF protocol, we supplement the formal specification to express more detailed behaviors that is not specified definitely in the standard. We also formally verify the interoperability and the safety of the protocol state machine of the specification. By showing that the formal specification specify all of the states and the transition events that appear in the standard document of the OSPF protocol, we prove that the state machine has the completeness, and prove it has the interoperability. To prove that the specification of the protocol has the safety, we formally verify the reachability, the liveness, the livelock-free property, and the deadlock-free property. As a result, we prove the protocol has the consistency. The specification and the validation are also effective to the OSPF Version 3 that inherit the protocol mechanism of the OSPF Version 2.

수세기를 통한 순열과 조합의 이해

  • Jung, In-Chul
    • East Asian mathematical journal
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    • v.25 no.3
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    • pp.247-262
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    • 2009
  • Permutation and combination are the part of mathematics which can be introduced the pliability and diversity of thought. In prior studies of permutation and combination, there treated difficulties of learning, strategy of problem solving, and errors that students might come up with. This paper provides the method so that meaningful teaching and learning might occur through the systematic approach of permutation and combination. But there were little prior studies treated counting numbers that basic of mathematics' action. Therefore this paper tries to help the understanding of permutation and combination with the process of changing from informal knowledge to formal knowledge.

A Similarity Measurement and Visualization Method for the Analysis of Program Code (프로그램 코드 분석을 위한 유사도 측정 및 가시화 기법)

  • Lee, Youngjoo;Lee, Jeongjin
    • Journal of Korea Multimedia Society
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    • v.16 no.7
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    • pp.802-809
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    • 2013
  • In this paper, we propose the similarity measurement method between two program codes by counting the frequency and length of continuous patterns of specifiers and keywords, which exist in two program codes. In addition, we propose the visualization method of this analysis result by formal concept analysis. Proposed method considers adjacencies of specifiers or keywords, which have not been considered in the previous similarity measurements. Proposed method can detect the plagiarism by analyzing the pattern in each function regardless of the order of function call and execution. In addition, the result of the similarity measurement is visualized by the lattice of formal concept analysis to increase the user understanding about the relations between program codes. Experimental results showed that proposed method succeeded in 96% plagiarism detections. Our method could be applied into the analysis of general documents.

A Formal Mtehod on Conformance Testing for AIN Protocol Test Generation (형식기술법에 의한 AIN 프로토콜 적합성 시험 계열 생성)

  • Kim, Sang-Ki;Kim, Seong-Un;Jeong, Jae-Yun
    • The Transactions of the Korea Information Processing Society
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    • v.4 no.2
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    • pp.552-562
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    • 1997
  • This paper proposes a formal method on confromance testing for INAP(AIN) test sequence generation by optimization technique.In order to implement and prove the dffectiveness of the proposed method,we specify the SRSM of INAP protocol SRF in SDL and generate I/O FSM by using our S/W tool. We generate an opti-mal test sequence by applying our method our method to this reference I/O FSM. We prove experimentally that the length of the generated test sequence by our method is more effective and shorter(i.e 32% improved)than the one geverated by UIO method,and estimate that The test coverage space of our test sequence is larger that of UIO method.

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Use of Reading Aloud Method in a Formal College-Level English Reading Classroom

  • Jeon, Jongmin
    • English Language & Literature Teaching
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    • v.17 no.3
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    • pp.57-71
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    • 2011
  • The purpose of this study is to investigate the possibility of the use of reading aloud as a way of teaching English reading in a formal college-level English reading classroom. The study tried to examine the effects of reading aloud on the development of English reading ability in terms of comprehension and speed and the students' perceptions of the use of reading aloud in an English reading classroom. The participants of the study were 36 third year students at a college. The results of the cloze test and reading speed test showed that reading aloud had a positive effect on the improvement of English reading ability. The students received higher scores in the cloze test after the course and read a text faster than before the course. The analysis of the course evaluation questionnaire indicated that the students in the study showed positive attitudes toward the use of reading aloud in an English reading classroom. Most of the students reported that reading aloud was an effective way of improving their English reading comprehension and speed. However, the students were not fully satisfied with the reading materials used in the study. The results of the present study indicated that reading aloud may be incorporated into a formal English reading classroom effectively.

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Middle and Elderly Women's Formal Knitwear Design Attributes Based on the Quality Function Deployment Theory (품질 기능 전개(QFD) 이론을 적용한 중.노년층 여성 니트 정장 디자인 속성)

  • Park, Jae-Ok;Lee, Yoon-Mee
    • The Research Journal of the Costume Culture
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    • v.17 no.3
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    • pp.484-498
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    • 2009
  • The purpose of this study is to explore the applicability of QFD to product development of clothes by empirically applying it to development of a specific clothes, middle and elderly women’s formal knitwear. The voices of customers(VOCs) for formal knitwear was collected through in-depth interviews with 25 customers, shop masters, and designers. Also, questionnaires of which respondents were 230 customers were used to rank the importance of the items of VOC. A QFD team of 10 knitwear experts implemented the task of translating VOCs into design attributes and measuring the values of the relationships between VOCs and design attributes. Importance ranking of the items of design attributes was obtained based on Lyman's method. The results of this study were as follows. First, the customer requirements for formal knitwear were classified into five dimensions, that is, symbolism, aesthetic, fitness, usefulness, and maintenance. Second, the descending order of the necessity of improving the quality was maintenance, aesthetic, fitness, usefulness, and symbolism. Third, three-staged design attributes were obtained as a result of translating of VOCs into design attributes. Lastly, the descending order of the importance of design attributes was "sorts of yarn", "sorts of color jacquard", "color", "tone", "ease", etc.

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STATE TOKEN PETRI NET MODELING METHOD FOR FORMAL VERIFICATION OF COMPUTERIZED PROCEDURE INCLUDING OPERATOR'S INTERRUPTIONS OF PROCEDURE EXECUTION FLOW

  • Kim, Yun Goo;Seong, Poong Hyun
    • Nuclear Engineering and Technology
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    • v.44 no.8
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    • pp.929-938
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    • 2012
  • The Computerized Procedure System (CPS) is one of the primary operating support systems in the digital Main Control Room. The CPS displays procedure on the computer screen in the form of a flow chart, and displays plant operating information along with procedure instructions. It also supports operator decision making by providing a system decision. A procedure flow should be correct and reliable, as an error would lead to operator misjudgment and inadequate control. In this paper we present a modeling for the CPS that enables formal verification based on Petri nets. The proposed State Token Petri Nets (STPN) also support modeling of a procedure flow that has various interruptions by the operator, according to the plant condition. STPN modeling is compared with Coloured Petri net when they are applied to Emergency Operating Computerized Procedure. A converting program for Computerized Procedure (CP) to STPN has been also developed. The formal verification and validation methods of CP with STPN increase the safety of a nuclear power plant and provide digital quality assurance means that are needed when the role and function of the CPS is increasing.

Effects of Formal and Informal Control Combination on Information Systems Outsourcing Consequence: Based on IT Governance Perspectives (공식적, 비공식적 통제 결합이 정보시스템 아웃소싱 결과에 미치는 영향:IT 거버넌스 관점)

  • Lee, Jong-Man
    • Journal of Internet Computing and Services
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    • v.11 no.2
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    • pp.155-164
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    • 2010
  • The purpose of this paper is to propose critical success factors for effectively managing information systems(IS) outsourcing. The survey method was used for this paper, and data from a total 106 companies that were listed greater than $10 million were used for the analysis. To analyze the data, structural equation model was used. The results of this empirical study is summarized as follows. First, both formal control based on contract and informal control based on trust have a positive effect on control level which is a determinant indicator of IS outsourcing performance. Second, management capability such as preparedness capability and relationship capability have a positive effect on formal and informal control mechanism. The findings have important implications for the role of trust and management capability in formal management control.

ForTIA : A Tool Supporting Formal Method based on LOTOS (ForTIA: LOTOS 기반의 정형기법 지원도구)

  • Cho, Soo-Sun;Cheon, Yoon-Sik;Oh, Young-Bae;Chung, Yun-Dae
    • Journal of KIISE:Computing Practices and Letters
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    • v.6 no.2
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    • pp.161-172
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    • 2000
  • In this paper, we introduce the development of a LOTOS-based tool, supporting formal methods, called ForTIA (A Formalism for Telecommunication and Information Systems). By using LOTOS, an ISO standard formal specification language, the user requirements and system models can be abstracted and represented formally. Therefore, the system can be validated and verified on the specifications, before implementations. ForTIA supports light-weight formal methods based on validation to be used in real industry. Key functions of ForTIA are simulation and C++ code generation. In simulation, tree based visual validation mechanism is provided and in code generation, the full C++ source code is generated to be used for system implementations.

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Formal Verification and Performance Analysis of New Communication Protocol for Railway Signaling Systems (철도 신호시스템을 위한 새로운 통신 프로토콜의 성능해석 및 검증)

  • 이재호;황종규;박용진;박귀태
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.53 no.6
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    • pp.380-387
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    • 2004
  • In accordance with the computerization of railway signaling systems, the interface link between the signaling systems has been replaced by a digital communication channel. At the same time, the importance of the communication link has become increasingly significant. However, there are some questionable matters in the current state of railway signaling systems in KNR. First, different communication protocols have been applied to create an interface between railway signaling systems although the protocols have the same functions. Next, the communication protocols currently used in the railway fields have some illogical parts such as structure, byte formation, error correction scheme, and so on. To solve these matters, the standard communication protocol for railway signaling systems is designed. The newly designed protocol is overviews in this paper. And the simulation is performed to analysis the performance of data link control for designed protocol. According to this simulation, it is identified that the link throughput of new protocol is improved about 10% and the frame error rate is improved than existing protocol. And it is verified the safety and liveness properties of designed protocol by using a formal method for specifying the designed protocol. It is expected that there will be an increase in safety, reliability and efficiency in terms of the maintenance of the signaling systems by using the designed communication protocol for railway signaling.