• Title/Summary/Keyword: Formal method

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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accordance with the computerization of railway signaling systems, the interface link between the signaling systems has been replaced by a digital communication channel.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.

Network, Channel, and Geographical Proximity of Knowledge Transfer: The Case of University-Industry Collaboration in South Korea

  • Kwon, Ki-Seok;Jang, Duckhee;Park, Han Woo
    • Asian Journal of Innovation and Policy
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    • v.4 no.2
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    • pp.242-262
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    • 2015
  • The relationship between geographical proximity and academics' formal and informal knowledge-transfer activities in the network is analyzed with a mixed research method. With social network analysis as a basis, we have explored the networks between academics and firms in the 16 regions of South Korea. The result shows Seoul and Gyunggi are identified as central nodes, meaning that the academics in other regions tend to collaborate with firms in these regions. An econometric analysis is performed to confirm the localization of knowledge-transfer activities. The intensity of formal channels measured by the number of academic papers is negatively, but significantly associated with the geographical proximity. However, we have not found any significant relationship between the formality of the channels and geographical proximity. Possibly, the regional innovation systems in South Korea are neither big enough nor strong enough to show a localization effect.

PLC Real Time OS Verification & Validation in Formal Methods (정형기법을 이용한 PLC RTOS 검증)

  • Choi, Chang-Ho;Song, Seung-Hwan;Yun, Dong-Hwa;Hwang, Sung-Jae
    • Proceedings of the KIEE Conference
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    • 2005.07d
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    • pp.2489-2491
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    • 2005
  • Currently, Programmable Logic Contorller(PLC) uses Real Time Operation System(RTOS) as basic OS. RTOS executes defined results as to defined time. General features of RTOS emphasize the priority in each task, high-speed process of external interrupt, task scheduling, synchronization in task, the limitation of memory capacity. For safety critical placement, PLC software needs Verification and Validation(V&V). For example, nuclear power plant. In this paper, PLC RTOS is verified by formal methods. Particularly, formal method V&V uses verification tool called 'STATEMATE', and shows the results.

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Product Family Design using Formal Concept Analysis and Ontology (정형적 개념 분석과 온톨로지를 활용한 제품계열 정보 설계)

  • Lee, Hee-Jung
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.35 no.3
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    • pp.110-117
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    • 2012
  • A product family design has received much attention over the last several decades, since a product family-based development shortens lead-times and reduces cost, as well as increases efficiency and effectiveness of the product realization process. It is challenging work, however, to define the product family design in the heterogeneous product development environments, due to myriads of products related information described in different ways across products in any companies. In this paper, we provided a way of defining product family design framework using formal concept analysis and ontology language. Based on this, the specific product family can be derived by ontological reasoning, and the new product concept can be also expanded in the framework. The proposed framework is formalized using OWL (Web Ontology Language) and implemented in $Prot{\acute{e}}g{\acute{e}}$. Actual product family design algorithm is carried out using FaCT++ engine, a plug-in to $Prot{\acute{e}}g{\acute{e}}$, and the benefits of the proposed method are also demonstrated through a case study.

Formal Modeling and Verification of an Enhanced Variant of the IEEE 802.11 CSMA/CA Protocol

  • Hammal, Youcef;Ben-Othman, Jalel;Mokdad, Lynda;Abdelli, Abdelkrim
    • Journal of Communications and Networks
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    • v.16 no.4
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    • pp.385-396
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    • 2014
  • In this paper, we present a formal method for modeling and checking an enhanced version of the carrier sense multiple access with collision avoidance protocol related to the IEEE 802.11 MAC layer, which has been proposed as the standard protocol for wireless local area networks. We deal mainly with the distributed coordination function (DCF) procedure of this protocol throughout a sequence of transformation steps. First, we use the unified modeling language state machines to thoroughly capture the behavior of wireless stations implementing a DCF, and then translate them into the input language of the UPPAAL model checking tool, which is a network of communicating timed automata. Finally, we proceed by checking of some of the safety and liveness properties, such as deadlock-freedom, using this tool.

Frame Analysis of Newspaper's Coverage Related to Leisure of Older Adults (노인여가관련 신문보도의 프레임 분석)

  • Oh, Sae-Sook;Kim, Jong-Soon;Shin, Kyu-Lee
    • Journal of Wellness
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    • v.7 no.2
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    • pp.25-37
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    • 2012
  • The purpose of this study was to analyze the mass media's news framing on the elderly leisure. For this, researchers collected news articles from daily newspapers such as Chosun Ilbo, Hankyoreh, Kyunghyang Shinmun, and analysed the news framing of them through text-analytic approach. Total of 153 news the about elderly leisure between 1990 and 2010 were used for frame analysis. The Frame analyses were divided by formal frame and content frame. The formal frame was formed by deduction based on the classification method of Iyergar(1991) and the content frame was formed by induction according to the analysis of overall themes and titles of news. The main result could be summarized as follows: First, the analysis of formal frame showed that the episodic frame was predominantly high which focused on specific event or occurrences about elderly leisure. Second, it was found by content frame analysis that elderly leisure's facilities, health, serious leisure, policy frame were main subjects of news framing.

A Safety Verification of the Modified BLP Model using PVS (PVS를 이용한 수정된 BLP 모델의 안전성 검증)

  • Koo Ha-Sung;Park Tae-Kue;Song Ho-Keun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.8
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    • pp.1435-1442
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    • 2006
  • The ideal method of safety evaluation is to verify results of execution against all possible operations within operating system, but it is impossible. However, the formal method can theoretically prove the safety on actual logic of operating system. Therefore we explain the contents of the art of the safety verification of security kernel, and make a comparative study of various standardized formal verification tools. And then we assigned PVS(Prototype Verification system) of SRI(Stanford Research Institute) to verify the safety of a modified BLP(Bell & LaPadula) model, the core access control model of multi-lavel based security kernel. Finally, we describe formal specification of the revised BLP model using the PVS, and evaluate the safety of the model by inspecting the specification of the PVS.

NuDE 2.0: A Formal Method-based Software Development, Verification and Safety Analysis Environment for Digital I&Cs in NPPs

  • Kim, Eui-Sub;Lee, Dong-Ah;Jung, Sejin;Yoo, Junbeom;Choi, Jong-Gyun;Lee, Jang-Soo
    • Journal of Computing Science and Engineering
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    • v.11 no.1
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    • pp.9-23
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    • 2017
  • NuDE 2.0 (Nuclear Development Environment 2.0) is a formal-method-based software development, verification and safety analysis environment for safety-critical digital I&Cs implemented with programmable logic controller (PLC) and field-programmable gate array (FPGA). It simultaneously develops PLC/FPGA software implementations from one requirement/design specification and also helps most of the development, verification, and safety analysis to be performed mechanically and in sequence. The NuDE 2.0 now consists of 25 CASE tools and also includes an in-depth solution for indirect commercial off-the-shelf (COTS) software dedication of new FPGA-based digital I&Cs. We expect that the NuDE 2.0 will be widely used as a means of diversifying software design/implementation and model-based software development methodology.

Formal Representation and Query for Digital Contents Data

  • Khamis, Khamis Abdul-Latif;Song, Huazhu;Zhong, Xian
    • Journal of Information Processing Systems
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    • v.16 no.2
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    • pp.261-276
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    • 2020
  • Digital contents services are one of the topics that have been intensively studied in the media industry, where various semantic and ontology techniques are applied. However, query execution for ontology data is still inefficient, lack of sufficient extensible definitions for node relationships, and there is no specific semantic method fit for media data representation. In order to make the machine understand digital contents (DCs) data well, we analyze DCs data, including static data and dynamic data, and use ontology to specify and classify objects and the events of the particular objects. Then the formal representation method is proposed which not only redefines DCs data based on the technology of OWL/RDF, but is also combined with media segmentation methods. At the same time, to speed up the access mechanism of DCs data stored under the persistent database, an ontology-based DCs query solution is proposed, which uses the specified distance vector associated to a surveillance of semantic label (annotation) to detect and track a moving or static object.

Three-dimensional Elastic Green's Solution by Formal Time-integration Method (시간적분을 이용한 3차원 탄성파 임펄스 반응 해의 계산)

  • Park Kwon Gyu;Shin Changsoo;Yoon Kwangjin;Suh Jung Hee
    • Geophysics and Geophysical Exploration
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    • v.3 no.4
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    • pp.125-128
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    • 2000
  • An ad hoc method of deriving three-dimensional elastic Greens solution for displacements is proposed in this study; Instead of direct evaluation of four-dimensional Fourier integral that is usual in spectral approaches, we first derived the expression for particle acceleration using the calculus of residues, and then, derived the expression for particle displacement by direct formal integration with respect to time. As a result, we can detour the disconcertion related to causality due to directly evaluating the integral with respect to angular frequency in conventional spectral approach.

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