• School Mathematics
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• v.14 no.4
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• pp.445-468
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• 2012

This study is tried in order to link informal arithmetic reasoning to formal algebraic reasoning. In this study, we investigated elementary school student's non-formal algebraic reasoning used in algebraic problem solving. The result of we investigated algebraic reasoning of 839 students from grade 1 to 6 in two schools, Korea, we could recognize that they used various arithmetic reasoning and pre-formal algebraic reasoning which is the other than that is proposed in the text book in word problem solving related to the linear systems of equation. Reasoning strategies were diverse depending on structure of meaning and operational of problems. And we analyzed the cause of failure of reasoning in algebraic problem solving. Especially, 'quantitative reasoning', 'proportional reasoning' are turned into 'non-formal method of substitution' and 'non-formal method of addition and subtraction'. We discussed possibilities that we are able to connect these pre-formal algebraic reasoning to formal algebraic reasoning.

• 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).

• International Journal of Computer Science & Network Security
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• v.24 no.5
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• pp.33-39
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• 2024

In a previous study we proceeded to the remodularization architecture based on classes and packages using the Formal Concept Analysis (FCA)[13] [14] [30]. we then got two possible remodularized architectures and we explored the issue of redistributing classes of a package to other packages, we used an approach based on Oriented Graph to determine the packages that receive the redistributed classes and we evaluated the quality of a remodularized software architecture by metrics [31] [28] [29]. In this paper, we will address the issue of the efficiency of the Oriented Graph in the remodularization of software architectures compared to the Formal Concept Analysis FCA method. The formal method of FCA concept is not popularized among scientists as opposed to the use of the labeled directed graph. It is for this reason that our directed graph approach is more effective in its simplicity and popularity.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.258-259
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• 2013

Recently, architectural design has been changing from formal design to freeform design due to the digitalization of construction industry. Especially, the formal design has been accepted as a design trend recently and applied many times as a design concept in the architectural design competitions such as turn-key. However, various deflects such as water leak and cracks have been occurred because the traditional construction methods had been applied without any revision or adaptation of the formal construction method for the freeform building construction. Therefore this research proposes location point control method for freeform metal panel installation which is focused on the application of LH JinJu new office.

• Journal of The Korea Institute of Healthcare Architecture
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• v.27 no.3
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• pp.7-16
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• 2021

Purpose: This study identified the planning trends for formal and informal learning spaces in the college of medicine through literature reviews. And then, by the analysis of the actual condition of existing domestic facilities, It was organized the architectural planning baseline data and future directions for the formal and informal learning spaces in the college of medicine. Methods: This study was conducted using literature reviews on the existing medical education method and learning space planning. Subsequently on-site surveys and questionnaires were conducted at existing facilities. Results: In the past, learning space of the college of medicine was considered only a formal learning space such lecture rooms, labs. But lately it has been turned into a total learning concept that embraces shared learning spaces such as libraries, student spaces, amenities and common spaces such as lobbies and hallways. ① Formal learning spaces are composed of teaching and practice areas. Since It is the basic functions that comprise the college of medicine, this paper conducted a functional analysis based on the current operating system of the College of Medicine and provided baseline data on architectural planning such as function, layout, zoning, and detailed planning. ② The informal learning sharing space was divided into a library area and a student well-being and convenience area to analyze the real conditions of domestic medical college. In addition, by comparing the trends and differences in foreign medical colleges identified by literature analysis, this paper summarizes the need to revitalize informal learning spaces and their integration into formal learning spaces, architectural planning considerations, etc. Implications: the evolution of the learning method and the flexibility of the learning space bring about changes in the learning space.

• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.939-942
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• 2003

Design verification problem is emerging as an important issue to detect any design errors at the early stage of the design. Conventionally, design verifications have been done using a simulation technique. However, this technique has been proved not to cover all potential design errors. Therefore, formal technique is often used to verify digital circuits as an alternative. In this paper we adopted formal verification technique and verified some important properties derived from our pipelined digital systems, using SMV (Symbolic Model Verifier). Our example shows that model checking method (one of formal verification techniques) can be effectively performed in verifying the large digital systems.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10a
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• pp.486-488
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• 2000

본 연구는 정형기법을 사용하여 Safety-Critical System의 개발 방법론을 제시한다. Safety-Critical System의 전체적인 개발 과정을 제시하고 Safety-Critical System 중의 하나인 원자력 발전소 시스템 중 Reactor Protection System(RPS)을 정형 명세(Formal Specification)하고 정형 검증(Formal Verification)하는 과정과 그에 따른 각 과정의 Compliance를 확인하는 예를 든다. 여기서 정형 명세에는 Software Cost Reduction(SCR)이하는 도구가 사용되었고, 정형 검증에는 SPIN이, Compliance를 확인하는 데에는 Prototype Verification System(PVS)를 사용하였다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.5
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• pp.169-174
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• 2009

In this paper, We define convert rules objects and relation presented in object model to the state and operation domain in formal specification. we implement simulation tool in order to verification method of formal specification and to consistency verified model between user's requirement. It is possible to select the suitable model and reduce the costs and efforts on software development.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.856-862
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• 2006

In railway signalling system, there are several kinds of signal system such as signals, signs, marker. The signals allows train to go or not, the signs permit to communicate between railway men, and the marks indicate status of railway lines. In KNR, the application of the signal systems are defined in railway operational regulations, operational related regulation, Operation safety critical system manipulation manual, and so on. In this paper, we extracted regulations for signalling system operation from related regulations, reviewed compatibility and contradiction for signalling system operations. We tried to check logical integrity of informal signalling operation regulation using formal method.

• Journal of Appropriate Technology
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• v.7 no.2
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• pp.172-187
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• 2021

In remote villages without access to modern IT technology, simple devices such as smartcards can be used to carry out business transactions. These devices typically store multiple business applications from multiple vendors. Although devices must prevent malicious or accidental security breaches among the applications, a secure communication channel between two applications from different vendors is often required. In this paper, first, we propose a method of establishing secure communication channels between applications in embedded operating systems that run on multi-applet smart cards. Second, we enforce the high assurance using an intransitive noninterference security policy. Thirdly, we formalize the method through the Z language and create the formal specification of the proposed secure system. Finally, we verify its correctness using Rushby's unwinding theorem.