• Title/Summary/Keyword: modal logic

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A Proof Mechanism for Knowledge and Belief Based on Deduction Model (추론모형에 기초한 믿음과 지식의 증명)

  • 김영훈;한상기
    • Korean Journal of Cognitive Science
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    • v.1 no.2
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    • pp.347-360
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    • 1989
  • Retearches on epistemology for artificial intelligence have started quite recently.Recently,Konolige made a contribution to epistemology by proposing a deduction model based on an efficieit modal logic for a proof mechanism for belief.In this thesis,a unified and generalized proof mechanism for the epistemic logic using a formal system called a View is pesented.In addition,the algorithm to adapt the theorem prover according to the given rule schema,which charncterizes the deduction model of the epistemic logic,is constructed. With this algorlthm,multiple agents having different rule schemas can co-exist in the proposed system. The soundness and completeness of the proposed proof mechanism is proved and a simple theorem prover is implemented to demonstrate the usefulness and practilcality.

De re context and some semantic traits of 'rago' (대물(de re) 문맥과 '-라고'의 몇 가지 의미론적 특성)

  • Min, Chanhong
    • Korean Journal of Logic
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    • v.16 no.1
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    • pp.61-85
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    • 2013
  • The author, after introducing the concept of de re belief and discussing de re/de dicto ambiguity in belief context and modal context, concludes that modal sentences of Korean language does not show any distinctive traits against English. He, after discussing this ambiguity in negative sentence a la Russell, tries to show that Korean provides two way of negation construction, one of which corresponds to de re negation (primary occurrence in Russell's terms). De re reading makes referentially transparent context, thus permits substitutions of identicals salva veritate; De dicto reading does not. Korean ending 'rago', used with quotation verbs, speech act verbs and cognitive attitude verbs, deserves some attention in that it permits de re sentences in addition to de re/de dicto ambiguous sentences. 'Rago' also makes speaker's commitment to the content of the intensionally contained clause 'neutral', in contrast with other Korean endings such as 'um/im' and 'raneun gut' which make speaker's positive commitment. This explains why the maxim of western epistemology that knowledge presupposes truth does not hold in Korean 'rago' sentences.

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Formal Verification Network-based Protocol for Railway Signaling Systems

  • Hwang, Jong-Gyu;Lee, Jae-Ho
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.354-357
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    • 2004
  • According to the computerization of railway signaling systems, the interface link between the signaling systems has been replaced by the digital communication channel. At the same time, the importance of the communication link is more pronounced than in the past. In this paper, new network-based protocol for Korean railway signaling has designed between CTC and SCADA system, and the overview of designed protocol is briefly represented. Using the informal method for specifying the communication protocol, a little ambiguity may be contained in the protocol. To clear the ambiguity contained in the designed protocol, we use LTS model to design the protocol for this interface link between CTC and SCADA, the LTS is an intermediate model for encoding the operational behavior of processes. And then, we verify automatically and formally the safety and the liveness properties through the model checking method. Especially, the modal ${\mu}$-calculus, which is a highly expressive method of temporal logic that has been applied to the model checking method. It will be expected to increase the safety, reliability and efficiency of maintenance of the signaling systems by using the designed protocol for railway signaling in Korea.

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Mechanical verification logic and first test results for the Euclid spacecraft

  • Calvi, Adriano;Bastia, Patrizia;Suarez, Manuel Perez;Neumann, Philipp;Carbonell, Albert
    • Advances in aircraft and spacecraft science
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    • v.7 no.3
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    • pp.251-269
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    • 2020
  • Euclid is an optical/near-infrared survey mission of the European Space Agency (ESA) to investigate the nature of dark energy, dark matter and gravity by observing the geometry of the Universe and the formation of structures over cosmological timescales. The Euclid spacecraft mechanical architecture comprises the Payload Module (PLM) and the Service Module (SVM) connected by an interface structure designed to maximize thermal and mechanical decoupling. This paper shortly illustrates the mechanical system of the spacecraft and the mechanical verification philosophy which is based on the Structural and Thermal Model (STM), built at flight standard for structure and thermal qualification and the Proto Flight Model (PFM), used to complete the qualification programme. It will be submitted to a proto-flight test approach and it will be suitable for launch and flight operations. Within the overall verification approach crucial mechanical tests have been successfully performed (2018) on the SVM platform and on the sunshield (SSH) subsystem: the SVM platform static test, the SSH structure modal survey test and the SSH sine vibration qualification test. The paper reports the objectives and the main results of these tests.

Development of Verification and Conformance Test Generation of Communication Protocol for Railway Signaling Systems

  • Lee, Jae-Ho;Hwang, Jong-Gyu;Seo, Mi-Seon;Kim, Sung-Un;Park, Gwi-Tae
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.358-362
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    • 2004
  • Verification and testing are complementary techniques that are used to increase the level of confidence in the correct functioning of communication systems as prescribed by their specifications. This paper presents an experience of model checking for a formal railway signaling protocol specified in LTS (Labeled Transition System). This formal approach checks deadlock, livelock and reachability for the state and action to verify whether properties expressed in modal logic are true on specifications. We also propose a formal method for semi-automated test case generation for a railway signaling protocol described in I/O FSM (Input/Output Finite State Machine). This enables the generation of more complete and consistent test sequence for conformance testing. The above functions are implemented by C++ language and included within RSPVTE (Railway Signaling Protocol Verification and Testing Environment).

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Verifying Correctness of Rail Signal Control Protocols Specified in LTS (LTS로 명세화 된 철도 신호제어용 프로토콜 검증)

  • 서미선;정창현;이재호;황종규;김성운
    • Proceedings of the IEEK Conference
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    • 2003.07a
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    • pp.454-457
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    • 2003
  • 대규모 시스템 명세의 올바름을 검증하기 위한 유한상태 LTS(Labeled Transition System)에 기반을 둔 CTL(Computation Tree Logic) 논리 적용의 문제점은 시스템 내부의 병렬 프로세스간 상호 작용으로 인한 상태폭발이다. 그러나 medal mu-calculus 논리를 시스템 안전성 및 필연성 특성 명세에 사용하면, 행위에 의한 순환적 정의가 가능하므로 상태폭발 문제가 해결된다. 본 논문에서는 LTS 로 명세화 된 철도 신호제어용 프로토콜 모델의 안전성 및 필연성 특성을 모형 검사 기법에 의해 검증하기 위해 시제 논리로 사용된 modal mu-calculus를 사용하여 해당 검정 알고리즘을 구현 및 적용하였다.

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A Simulation of "Self-Organizing Fuzzy Controller" for a Dynamic System under Irregular Disturbance (확률론적 가진을 받는 동적계에 대한 자기구성 퍼지제어기의 구현)

  • Yeo, Woon-Joo;Oh, Yong-Sul;Jung, Quen-Yong;Heo, Hoon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.05a
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    • pp.1058-1062
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    • 2003
  • This paper proposes a self-organizing fuzzy controller (SOFC) design technique applied to the vibration control of a dynamic system under irregular disturbance. In this controller, the fuzzy rules generate control signal continuously using the array of input and output pairs without using any special controller model. The generated rules are saved in the fuzzy rule matrix in real-time by self-organizing methods. This fuzzy logic control is demonstrated by simulation and shows the efficiency of the real-time self-organizing fuzzy controller in this system.

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A Study on Multi-modal Near-IR Face and Iris Recognition on Mobile Phones (휴대폰 환경에서의 근적외선 얼굴 및 홍채 다중 인식 연구)

  • Park, Kang-Ryoung;Han, Song-Yi;Kang, Byung-Jun;Park, So-Young
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.45 no.2
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    • pp.1-9
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    • 2008
  • As the security requirements of mobile phones have been increasing, there have been extensive researches using one biometric feature (e.g., an iris, a fingerprint, or a face image) for authentication. Due to the limitation of uni-modal biometrics, we propose a method that combines face and iris images in order to improve accuracy in mobile environments. This paper presents four advantages and contributions over previous research. First, in order to capture both face and iris image at fast speed and simultaneously, we use a built-in conventional mega pixel camera in mobile phone, which is revised to capture the NIR (Near-InfraRed) face and iris image. Second, in order to increase the authentication accuracy of face and iris, we propose a score level fusion method based on SVM (Support Vector Machine). Third, to reduce the classification complexities of SVM and intra-variation of face and iris data, we normalize the input face and iris data, respectively. For face, a NIR illuminator and NIR passing filter on camera are used to reduce the illumination variance caused by environmental visible lighting and the consequent saturated region in face by the NIR illuminator is normalized by low processing logarithmic algorithm considering mobile phone. For iris, image transform into polar coordinate and iris code shifting are used for obtaining robust identification accuracy irrespective of image capturing condition. Fourth, to increase the processing speed on mobile phone, we use integer based face and iris authentication algorithms. Experimental results were tested with face and iris images by mega-pixel camera of mobile phone. It showed that the authentication accuracy using SVM was better than those of uni-modal (face or iris), SUM, MAX, NIN and weighted SUM rules.

Local Model Checking for Verification of Real-Time Systems (실시간 시스템 검증을 위한 지역모형 검사)

  • 박재호;김성길;황선호;김성운
    • Journal of Korea Multimedia Society
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    • v.3 no.1
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    • pp.77-90
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    • 2000
  • Real-Time verification is a procedure that verifies the correctness of specification related to requirement in time as well as in logic. One serious problem encountered in the verification task is that the state space grows exponentially owing to the unboundedness of time, which is termed the state space explosion problem. In this paper, we propose a real-time verification technique checking the correctness of specification by showing that a system model described in timed automata is equivalent to the characteristic of system property specified in timed modal-mu calculus. For this, we propose a local model checking method based on the value of the formula in initial state with constructing product graph concerned to only the nodes needed for verification process. Since this method does not search for every state of system model, the state space is reduced drastically so that the proposed method can be applied effectively to real-time system verification.

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Development of Communication Protocol Verification Tool for Vital Railway Signaling Systems

  • Hwang, Jong-Gyu;Jo, Hyun-Jeong;Lee, Jae-Ho
    • Journal of Electrical Engineering and Technology
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    • v.1 no.4
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    • pp.513-519
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    • 2006
  • As a very important part in development of the protocol, verifications for developed protocol specification are complementary techniques that are used to increase the level of confidence in the system functions by their specifications. Using the informal method for specifying the protocol, some ambiguity may be contained therein. This indwelling ambiguity in control systems can cause the occurrence of accidents, especially in the case of safety-critical systems. To clear the vagueness contained in the designed protocol, we use the LTS (Labeled Transition System) model to design the protocol for railway signaling. And then, we verify the safety and the liveness properties formally through the model checking method. The modal ${\mu}$-calculus, which is an expressive method of temporal logic, has been applied to the model checking method. We verify the safety and liveness properties of Korean standard protocol for railway signaling systems. To perform automatic verification of the safety and liveness properties of the designed protocol, a communication verification tool is implemented. The developed tools are implemented by C++ language under Windows XP. It is expected to increase the safety and reliability of communication protocol for signaling systems by using the developed communication verification tool.