• Journal of the Korea Safety Management & Science
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• v.17 no.1
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• pp.179-192
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• 2015

In an automated industry PLC plays a central role to control the automation system. Therefore, fault free operation of PLC controlled automation system is essential in order to maximize a firm's productivity. A prior test of control system is a practical way to check fault operations, but it is a time consuming job and can not check all possible fault operation. A formal verification of PLC program could be a best way to check all possible fault situation. Tracing the history of the study on formal verification, we found three problems, the first is that a formal representation of PLC control system is incomplete, the second is a state explosion problem and the third is that the verification result is difficult to use for the correction of control program. In this paper, we propose a transformation method to reproduce the control system correctly in formal model and efficient procedure to verify and correct the control program using verification result. To demonstrate the proposed method, we provided a suitable case study of an automation system.

• Journal of the Korea Society of Computer and Information
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• v.12 no.6
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• pp.123-130
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• 2007

In this paper, We define convert rules from objects and relation presented in object model to the state and operation domain in formal specification. Namely, object and relation in information model converted to state domain in formal specification. State, event and behavior converted to operation domain. And that way informal object model change to formal language, it can be verify through formal method. Verification process make an offer convenience and confidence in software development early phase. And 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.

• Journal of Educational Research in Mathematics
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• v.13 no.1
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• pp.25-55
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• 2003

In the school mathematics, the negative numbers have been instructed by means of intuitive models(concrete situation models, number line model, colour counter model), inductive-extrapolation approach, and the formal approach using the inverse operation relations. These instructions on the negative numbers have caused students to have the difficulty in understanding especially why the rules of signs hold. It is due to the fact that those models are complicated, inconsistent, and incomplete. So, students usually should memorize the sign rules. In this study we studied on the didactical phenomenology of the negative numbers as a foundational study for the improvement of teaching negative numbers. First, we analysed the formal nature of the negative numbers and the cognitive obstructions which have showed up in the historic-genetic process of them. Second, we investigated what the middle school students know about the negative numbers and their operations, which they have learned according to the current national curriculum. The results showed that the degree they understand the reasons why the sign rules hold was low Third, we instructed the middle school students about the negative number and its operations using the formal approach as Freudenthal suggest ed. And we investigated whether students understand the formal approach or not. And we analysed the validity of the new teaching method of the negative numbers. The results showed that students didn't understand the formal approach well. And finally we discussed the directions for improving the instruction of the negative numbers on the ground of these didactical phenomenological analysis.

• 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.

• International Journal of Computer Science & Network Security
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• v.24 no.4
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• pp.192-196
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• 2024

The memory coherence problem occurs while mapping shared virtual memory in a loosely coupled multiprocessors setup. Memory is considered coherent if a read operation provides same data written in the last write operation. The problem is addressed in the literature using different algorithms. The big question is on the correctness of such a distributed algorithm. Formal verification is the principal term for a group of techniques that routinely use an analysis that is established on mathematical transformations to conclude the rightness of hardware or software behavior in divergence to dynamic verification techniques. This paper uses UPPAAL model checker to model the dynamic distributed algorithm for shared virtual memory given by K.Li and P.Hudak. We analyse the mechanism to keep the coherence of memory in every read and write operation by using a dynamic distributed algorithm. Our results show that the dynamic distributed algorithm for shared virtual memory partially fulfils its functional requirements.

• Archives of design research
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• v.4 no.1
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• pp.31-37
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• 1991

Process of thinking on the form in product design includes the process in which unclear requirements are transformed into defined concepts, and the process in which the design as a form conforming to the concepts in conc1uded.(The former is called fconceptualizationJ which deals with abstract matters, and the latter "manipulation of the formJ which deals with more embodied matters) In conceptualization process the operation which transform the diverse requirements in the initial phase of de\ulcornersign to related linguistic expressions or to an image that directly suggests the form is executed. In the process of manipulation of the form the transformation to design as the description of relationships between the formal elements of the design solution resulted from the transformed requirements. It is the job of selecting the most suitable formal elements, balancing the relationships between them, out 01 the possibilities that reside in the individual attributes of formal elements, and finally leading to the design as the end solution. This writing focuses down to the wilfulness and ambiguity of design, and the diversity of design solution after the requirements, formal elements, and the process of relating the formal attributes to each other is built up the two phases.ases.

• Journal of Construction Engineering and Project Management
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• v.3 no.1
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• pp.22-27
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• 2013

Inter-organizational Relationships (IORs) governance is one of the emerging research areas that have been studied in different contexts (e.g. economics, strategy, organization, and management). This view, particularly, attracted rising attention from academics and practitioners in the context of construction projects, due to the complex forms of IORs in terms of inter-firm exchanges (e.g. engineering, procurement, finance, construction, and operation) in these projects. The focus of IORs governance is to control Inter-organizational relationships among two or more cooperative parties to alleviate conflict and achieve mutual gains. One of the mechanisms that have been identified in the related literature is formal governance mechanism. Although many empirical studies have been conducted using formal governance terms and indicators, there isn't yet a consensual definition of this mechanism and its components that may cause misinterpretation of research results and also impede future research. This paper makes contribution to the concept of IORs governance by clarifying the meaning of formal governance mechanism and identifying different indicators of this mechanism that have been used and identified in previous studies. This provides an innovative and useful framework to understand formal governance mechanism and its application in construction projects.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.321-327
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• 2013

Inter-organizational Relationships (IORs) governance is one of the emerging research areas that have been studied in different contexts (e.g. economics, strategy, organization, and management). This view, particularly, attracted rising attention from academics and practitioners in the context of construction projects, due to the complex forms of IORs in terms of inter-firm exchanges (e.g. engineering, procurement, finance, construction, and operation) in these projects. The focus of IORs governance is to control Inter-organizational relationships among two or more cooperative parties to alleviate conflict and achieve mutual gains. One of the mechanisms that have been identified in the related literature is formal governance mechanism. Although many empirical studies have been conducted using formal governance terms and indicators, there isn't yet a consensual definition of this mechanism and its components that may cause misinterpretation of research results and also impede future research. This paper makes contribution to the concept of IORs governance by clarifying the meaning of formal governance mechanism and identifying different indicators of this mechanism that have been used and identified in previous studies. This provides an innovative and useful framework to understand formal governance mechanism and its application in construction projects.

• Hwankyungkyoyuk
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• v.22 no.1
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• pp.110-119
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• 2009

To promote environmental education of elementary and secondary school in Seoul for a sustainable development, researchers investigated and analysed the current situation of formal and non-formal environmental education in Seoul as well as their major problems. Based on these current situation and problems, the way to improve the environmental education of elementary and secondary school in Seoul was described. The final section deals with specific recommendations to accomplish the improvement of environmental education of elementary and secondary school in Seoul for a sustainable development as follows: 1) Integration of formal and non-formal environmental education system, 2) Establishment and operation of a regional environmental education center for community, 3) International cooperation, and 4) To provide high quality environmental education programs.

• Journal of Korean Elementary Science Education
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• v.23 no.4
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• pp.273-278
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• 2004

According to Piaget, children aged 11 are in the middle of concrete operation period and formal operation period. So, it is necessary to adopt the Learning Cycle Model (LCM) which helps students improve their cognitive development. After determining the test for the Science Concept of Matter (SCOM), the experimental group showed higher average than the comparative group in the post-test. In the sound understanding, the experimental group showed higher ratio than the comparative group. And in the ratio of imperfect, wrong understanding and no response, the experimental group was lower than the comparative group. On the questions that were needed the complicated inquiry, many students of both groups still couldn't find the fundamental cause. In forming the scientific conceptualization, there was a meaningful difference (p < .001) after post-test Analysis of Covariance (ANCOVA) with pre-test result. After determining the test for the Test Inquiry Science Process (TISP), the experimental group showed higher average than the comparative group in the post-test. In the category of basic inquiry process which is needed in concrete operation, there was a meaningful difference (p < .05). In the category of unified inquiry process which is needed in formal operation, they showed no meaningful difference (p > .05). Therefore, applying the LCM to the chapter of 'Solution and Dissolving' is more effective on improving the scientific conceptualization and on helping the concrete operation abilities than the teacher centered learning.