• School Mathematics
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• v.18 no.3
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• pp.441-455
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• 2016

The position as saying that the math learning needs to begin from what diversely presents concrete object or familiar situation is well known as a name dubbed CSA(Concrete-Semiconcrete-Abstract). Compared to this, a recent research by Kaminski, et al. asserts that learning an abstract concept first may be more effective in the aspect of knowledge transfer than learning a mathematical concept with concrete object of having various contexts. The purpose of this study was to analyze a class, which differently applied a guidance sequence of concrete object, semi-concrete object, and abstract concept in consideration of this conflicting perspective, and to confirm its educational implication. As a result of research, a class with the application of a concept starting from the concrete object showed what made it have positive attitude toward mathematics, but wasn't continued its effect, and didn't indicate significant difference even in achievement. Even a case of showing error was observed rather owing to the excessive concreteness that the concrete object has. This error wasn't found in a class that adopted a concept as semi-concrete object. This suggests that the semi-concrete object, which was thought a non-essential element, can be efficiently used in learning an abstract concept.

• The Transactions of the Korea Information Processing Society
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• v.4 no.3
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• pp.731-746
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• 1997

The usage of object models for the development of software has been frowung due to the prevalence of the ob-ject oriented paradigm.The object moedels produced as results of requirments analysis and design activities are vety veneficial to the implementation phase.It is even possible for source code to be genrated automatically if object models are concrete enough.Therefore system analyzers and desingners should make an dffort to refine theabstrace ogject model defined at.an early stage in order to achieve a more conrete object model.In general,re-fining an abstrace object model into a concrete model depends too much on the desigver's infromal experience.In this paper,we persent the refinement techniques required for concreting an abstract object model bassed on OMT(Object Modeling Technique)'s notation,We will discuss the definition of the abstraction level of an object model and the transformational rules of refinement.These transformational rules are currently applied to the design of a software tool,named Process Modeler,which is a major component of the software development process modeling system for ICS(Information Communication Service). Finally we can achieve a concrete object model which can easily be translated into C++ source code.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10b
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• pp.1261-1266
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• 2000

In the impact echo method, a stress pulse is introduced into an object at on accessible surface by a transmitter. The pulse propagates into the test object and is reflected by flaws or interfaces. In this paper, void and crack locations of concrete specimens were detected using impact echo method. In their modal identification procedures, the double least squares solution for Ibrahim Time Domain technique was used.

• Journal of the Korea Institute of Building Construction
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• v.8 no.5
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• pp.43-51
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• 2008

This study examines shear capacity performance and structural characteristics of reinforced concrete beam using carbon fiber sheet(CFS), g)ass fiber sheet(GFS), glass fiber steel plate(GSP) and carbon fiber bar CB) which are reinforcing materials for reinforced concrete beam in order to produce similar condition to repair and reinforce actual structure and aims to provide data available In designing and constructing reinforced concrete structures under the structural damage. This study obtains the following conclusions. After considering the shear experiment results. it was indicated that the CB reinforced test object was the best in the shear capacity improvement and ductility capacity as it was contained in the concrete and was all operated, Also, GFS reinforced test object indicated the reduced flexural capacity but good shear capacity. GSP reinforced test object had bigger reinforcing strength than other reinforcing test objects. On the other hand, it showed the lowest reinforcement effect as compared section thickness of reinforced material because it showed the bigger relativity a section thickness of reinforced material. If the adherence to the concrete is improved, it will seem to show bigger reinforcement effect.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.257-262
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• 1997

Reinforced concrete structures built on the seashore or in seawater are damaged from saltwater which cause to accelerate corrosion of reinforcing steel in concrete. Therefore, Corrosion of steel reinforcement of concrete structures become more and more serious, and prediction of service lives of concrete structures considering steel corrosion is needed much more. this research is to investigate basic physical properties of various corrosion inhibitors and to evaluate their corrosion resistance in concrete. The object of this study is develop appropriate corrosion protection systems so as to enhance the durability of concrete.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.1215-1222
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• 2005

The object of this thesis is an study on detailing for concrete reinforcement and analytical study for seismic behavior of underground reinforced concrete box structures using the established seismic analytical method. Using the established seismic analytical method that has been presented in various documents seismic behavior of buried reinforce concrete box structures is compared. From the comparsion, it is shown that feasibility and detailing detailng for concrete reinforcement and seismic method for seismic analysis of buried reinforced concrete box structures.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.10a
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• pp.352-361
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• 1998

The post-processing modules are parts of an integrated system for reinforced concrete structures. This modules are composed of two modules: member design module and calculation report module. The purpose of this paper is to develope modules that increase efficiency and usefulness of an integrated system used reinforced concrete structures design. The development of post-processing modules is necessary for user to design reinforced concrete structures conveniently and quickly. This modules are connected with central database for the benefit of storing amount of input/output data and being used system with little effort. Post-processing modules used Object-Oriented concepts and techniques include identity, classification, polymorphism, and inheritance. Member design module automatically converts no good members into satisfied members by changing section size or reinforcement bar arrangement. This module can be operated both independent member design modules with user input and a part of integrated system with database input. If user operates member design module, calculation report module is created automatically.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04b
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• pp.447-454
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• 1998

The main object of the study is that axial force-moment relationships for high strength concrete structures using reliability theory(Linear statstical method, Monte Carlo Simulation) including probability conception. And mean stress factors and centroid factors proposed to high strength concrete structures using reliability theory(Linear statstical method, Monte Carlo Simulation). Finally, The established experimental data for axial force-moment relationships are compared to the analytical data(data for Linear statstical method and Monte Carlo Simulation) for axial force-moment relationships in this analytical method.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.500-506
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• 1997

The main object of the study is that axial force-moment relationships for high strength concrete structures using reliability theory probability conception. And mean stress factors and centroid factors proposed to high strength concrete structures using reliability theory. Finally, the established experimental data for axial force-moment relationships are compared to the analytical data for the axial force-moment relationships in this analytical method.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.791-796
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• 1997

Deterioration of pavements or tunnels primarily from the existence of voids under the pavements or tunnel linings. To detect these voids effectively by non-destructive testes, a method using radar was proposed. In this research, the detection of shape of voids by radar image processing is investigate. The experiments and simulation were conducted to detect voids in or under concrete pavements for tunnel linings) with reinforcing bars. From the results, the fundamental algorithm for tracing the voids, improving the horizontal resolution of the object image and detecting shape of objects, was verified.