• Title/Summary/Keyword: Formal logic

Search Result 116, Processing Time 0.028 seconds

A Formal Safety Analysis for PLC Software-Based Safety Critical System using Z

  • Koh, Jung-Soo;Seong, Poong-Hyun;Son, Han-Seong
    • Proceedings of the Korean Nuclear Society Conference
    • /
    • 1997.05a
    • /
    • pp.153-158
    • /
    • 1997
  • This paper describes a formal safety analysis technique which is demonstrated by performing empirical formal safety analysis with the case study of beamline hutch door Interlock system that is developed by using PLC(Programmable Logic Controller) systems at the Pohang Accelerator Laboratory. In order to perform formal safety analysis, we have built the Z formal specifications representation from user requirement written in ambiguous natural language and target PLC ladder logic, respectively. We have also studied the effective method to express typical PLC timer component by using specific Z formal notation which is supported by temporal history. We present a formal proof technique specifying and verifying that the hazardous states are not introduced into ladder logic in the PLC-based safety critical system.

  • PDF

Didactical Issues Related to Necessary Condition and Sufficient Condition (필요조건, 충분조건 개념의 학습과 관련한 문제들)

  • Hong, Jin-Kon;Kong, Jung-Taek
    • Journal for History of Mathematics
    • /
    • v.28 no.4
    • /
    • pp.191-204
    • /
    • 2015
  • The reason of the confusion of learners about the logic concepts such as implication, necessary condition and sufficient condition can be analyzed from the point of view of history of logic, discrepancy between ordinary language and formal logic, and reification which occurs in the process of cognition of discursive object and also indicates the necessity of a research. This study analysed the difficulties related to study and implication concept and attempted to the reflection of textbook and curriculum. Not that ordinary language makes the introduction of formal language easier, but that this study discussed the possibilities ordinary language intervenes the learning of formal language. This study additionally intended to understand learning difficulties of concrete subjects, abstract subjects and the gap between primary object and discursive object by understanding the process of sagging, encapsulating and reifying.

Che-Yong(體用) Logic and Research Methodology

  • YongNam Yun
    • Development and Reproduction
    • /
    • v.26 no.4
    • /
    • pp.183-190
    • /
    • 2022
  • Today's Eastern philosophers try to use the formal logic organized by Aristotle, saying that there was no logic in the East. This researcher found that Confucius and other Asians used Che-Yong logic. The Che-Yong logic is based on the Che-Yong law, which is a natural law. The Che-Yong law consists of the Che-Yong principle and the Hyeon-Mi principle. The Hyeon-Mi principle is that if there is an appearance on the outside, there is a corresponding cause in it. The Che-Yong principle is that the highest common cause of various appearances is Che, and the Che grows and changes on its own to become a Yong. Identifying Che and predicting Yong is Che-Yong logic. Here, I'd like to introduce Che-Yong logic and suggest a new research methodology to apply it.

A CASE Tool for Automatic Generation of FBD Program from NuSCR Formal Specification (NuSCR 정형 요구사항 명세로부터 FBD 프로그램 자동생성을 위한 CASE 도구)

  • Back, Hyoung-Bu;Yoo, Jun-Beom;Cha, Sung-Deok
    • Journal of KIISE:Computing Practices and Letters
    • /
    • v.15 no.4
    • /
    • pp.265-269
    • /
    • 2009
  • Formal specification plays important roles in guaranteeing software safety of safety-critical systems such as nuclear power plant's digital control systems. We had developed a technique [1] which synthesizes Function Block Diagram(FBD) programs from NuSCR formal requirements specifications, but it did not be used widely as it had no automatic tool support. FBD is one of the programming languages for Programmable Logic Controllers(PLC) based system. This paper introduces a CASE tool, NuSCRtoFBD, developed to automate the synthesis procedure. The CASE tool NuSCRtoFBD can reduce a number of errors occurred in the process of manual FBD programming.

Reconsidering the Formal Accounts of Continuity in the Theory-Change from Newtonian to Einsteinian Physics

  • Yang, Kyoung-Eun
    • Korean Journal of Logic
    • /
    • v.12 no.2
    • /
    • pp.171-199
    • /
    • 2009
  • This essay will consider evolutionary views that attempt to capture the continuity of theory-change from Newtonian to Einsteinian physics via the formal aspects of these theories. Although it cannot be denied that the formal aspects such as 'correspondence principles' and 'covariance principles' provide important information concerning this theory-change, these formal properties are not sufficient to capture the essential elements of any evolutionary account of the development of Einstein's special and general theories of relativity from Newtonian mechanics.

  • PDF

How has belief modality contributed to formal semantics?

  • Tojo, Satoshi
    • Proceedings of the Korean Society for Language and Information Conference
    • /
    • 2007.11a
    • /
    • pp.42-53
    • /
    • 2007
  • Looking back the history of formal treatment of linguistics, we cannot disregard the contribution of possible world semantics. Intensional logic of Montague semantics, DRT (Discourse Representation Theory), mental space, and situation theory are closely related to or compared with the notion of possible world. All these theories have commonly clarified the structure of belief context or uncertain knowledge, employing hypothesized worlds. In this talk, I firstly brief the pedigree of these theories. Next, I will introduce the recent development of modal logic for the representation of (i) knowledge and belief and (ii) time, in which belief modality is precisely discussed together with the accessibility among possible worlds. I will refer to BDI (belief-desire-intention) logic, CTL (computational tree logic), and sphere-based model in belief revision. Finally, I will discuss how these theories could be applied to the further development of analyses of natural language.

  • PDF

A Formal Security Analysis on the Enhanced Route Optimization Protocol for Mobile IPv6 (이동 IPv6의 확장된 경로 최적화프로토콜에 대한 형식화된 보안 분석)

  • You, Il-Sun;Kim, Heung-Jun
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.13 no.4
    • /
    • pp.691-699
    • /
    • 2009
  • Recently, the ERO protocol has been adopted as a standard to protect the routing optimization mode introduced by MIPv6. This protocol uses the public key cryptography and the early binding update method to improve the Return Routeability protocol while optimizing both security and performance. On the other hand, though various security approaches including the ERO protocol have been proposed for MIPv6, they lack formal verification. Especially, to our best knowledge, there is no formal analysis on the ERO protocol. In order to provide a good example for formal analysis on MIPv6 security protocols, this paper verifies the correctness of the ERO protocol through BAN-logic. For this goal, BAN-logic is extended to consider the address tests on the mobile nodes's CoA and HoA. It is expected that the analysis presented in this paper will be useful for the formal verifications on the security protocols related to MIPv6.

Expressive Characteristics of Subversive Appropriation in Kim kwang soo's Architectural Design (김광수 건축디자인의 전복적 전유 표현특성)

  • Park, Young-Tae
    • Korean Institute of Interior Design Journal
    • /
    • v.27 no.1
    • /
    • pp.97-108
    • /
    • 2018
  • This study is based on the way Kim Kwang Soo works, which reveals a strong expressive tone that is rare in Korean architecture. His work is not decorative and symbolic representation of the intention of positive amusement. Therefore, the following noteworthy points will arise. The various phenomena associated with architecture and society are researched and analyzed in a critical manner. So, it creates and expresses its own formal logic. In this study, the theory of the subversive appropriation theory was identified by using the expressive characteristics of engagement. The study was based on a conceptual framework for the overturning of the mimesis, which Benjamin and Adorno have described. From this, this study summarizes Kim Kwang Soo's nihilistic attitude, finding boundaries and crack points, and subversive expression as a new form of architectural formal logic as main characteristics of interpretation of works. The characteristics of subversive expression of Kim Kwang Soo architecture derived from this are as follows. It does not take an ideological approach to the dismantling of the internalization of traditional Korean architecture. Popular culture and social phenomena are used as materials for expression. These are structured sensibly with appropriated formal logic. Finally, the architectural position adhered to the limit of performativity was recognized as the dimension of new meaning generation.