• Structural Engineering and Mechanics
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• v.37 no.6
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• pp.617-632
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• 2011

A concept of crash energy absorbing (CEA) lattice structure for an inflatable morphing vehicle body (Lee et al. 2008) has been investigated as a method of providing rigidity and energy absorption capability during a vehicular collision (Lee et al. 2007). A modified analytical model for the CEA lattice structure design is described in this paper. The modification of the analytic model was made with a stiffness approach for the elastic region and updated plastic limit analysis with a pure plastic bending deformation concept and amended elongation factors for the plastic region. The proposed CEA structure is composed of a morphing lattice structure with movable thin-walled members for morphing purposes, members that will be locked in designated positions either before or during the crash. What will be described here is how to model the CEA structure analytically based on the energy absorbed by the CEA structure.

• Journal of Fisheries and Marine Sciences Education
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• v.6 no.2
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• pp.198-216
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• 1994

The problem of promoting instructional effect using reorganizing the content of textbook is one of the major concerns of many education theorists and teachers. The results of many researches about above problem reveal that reorganizing the content of textbook promotes the ability of recall and problem solving of learners. The content structure of current navigation textbook revealed a categorical structure as its basic framework, though it seems to be a poor one. A categorical structure is known as providing an inferior information processing mechanism for learners than a learning hierarchy content structure is. Furthermore current content structure hasn't given any considerations to navigation in practice, spatial contexts and sequential events of ships from a harbor to another harbor. The learning hierarchy content structure has an advantage of giving learners more systematic and stronger knowledge networks than a categorical structure.

• The Mathematical Education
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• v.54 no.4
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• pp.365-383
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• 2015

Factorization asks the recognition of the structure of polynomials, compared to polynomial expansion with process characteristic. Therefore it makes students experience a lot of difficulties. This study aims to figure out causes of the difficulties by identifying students' cognitive characteristics in factorizing in the perspective of 'structure sense'. To do this, we gave six factorizing problems of three types to middle school students and selected six participants as interviewees based on the test results. They were classified into two categories, structure sense and non-structure sense. Through this interview, we figured out the interviewee's cognitive characteristics and the causes of difficulty in the perspective of structure sense. Furthermore, we suggested some didactical implications for encouraging structure sense in factorizing by identifying assistances and obstacles for recognition of structures.

• Bulletin of the Korean Chemical Society
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• v.25 no.8
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• pp.1241-1243
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• 2004

• Journal of Korean Port Research
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• v.13 no.2
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• pp.365-380
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• 1999

In this thesis the legal systems related to real estate and sea area utilization are studied in order to improve them for construction of Very Large Floating Structure. Main research subjects are as follows: 1) Whether can Very Large Floating Structure be accepted or not as real estate like house and land\ulcorner 2) How can the sea area which is occupied by Very Large Floating Structure be utilized\ulcorner As the conclusion, the Very Large Floating Structure can be registered as real estate even though it is not specified by Korean law for the present. The design concept of Very Large Floating Structure can be interpreted as satisfying enough necessary conditions and factors for Very Large Floating Structure to become real estate. In the near future, we have to make improvement on the laws related with the construction of Very Large Floating Structures so that private sectors can joint the construction. In additions, a new law for various floating structures should be made as soon as possible.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.8
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• pp.371-377
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• 2005

This paper Presents the Potential gradient characteristics of structure grounding electrode when a test current flows through grounding electrode. In order to analyze the potential gradient of ground surface on structure grounding electrode, the reduced scale model has been used. The potential gradient has been measured and analyzed for types of structure using the hemispherical grounding simulation system in real time. The structures were designed through reducing real buildings and fabricated with four types on a scale of one-one hundred sixty. The supporter was made to put up with weight of structure and could move into vertical, horizontal, rotary direction. When a test current flowed through structure grounding electrodes, ground potential rise was the lowest value at electric cage type(type B). According to resistivity and absorption percentage In concrete attached to structure, the potential distribution of ground surface appeared differently.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.251-252
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• 2015

Enough school facility maintenance data should be accumulated in a database or data warehouse in order to supply information about school facility correct maintenance budget plan, budget assignment, and cycle and rate of maintenance or replacement. For those, this research analyze the present school facility maintenance practice and budget and construction cost structure. In order to solve the problems, this study analyze the present practice of maintenance and replacement and obtain LCC(Life cycle cost) data, perform expert interview and then establish construction work breakdown structure of maintenance of educational facility by combining work breakdown structure(WBS) and cost breakdown structure(CBS).

• Bulletin of the Korean Chemical Society
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• v.25 no.12
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• pp.1937-1940
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• 2004

• Wind and Structures
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• v.3 no.4
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• pp.291-302
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• 2000

A new finite element technique to solve the problem of wind and structure interactions is presented. Conventionally, wind analysis is performed on the Eulerian description in which the finite element mesh would not move in accordance with the wind flow. However, it is not the case in wind-structure interaction problems because nodes attached to the surface of structure should move with the displacement of structure. The arbitrary Lagrangian-Eulerian (ALE) method treats the mesh and flow independently, and allow the mesh to move. In this study, the analysis domain is divided into regions of the structure, air around the structure and the interface of two regions. To satisfy the compatibility and equilibrium conditions between separated regions and to carry out the efficient analysis, the rigid link is used. Also the equation of wind and that of structure are arranged in a single matrix equation.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.36
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• pp.365-370
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• 1995

In recent years, there have been attempts to explain firms' capital structure based upon the agency theory which considers agency problems arising due to ownership structure. Agency theory starts from the coctractual relationship (explicit or implicit) between principals and agents. Since uncertainty exists in real world and information is distributed asymmetrically, there are conflicts between principals and agents. The objectives of this study are to analyze, based upon agency theory, factors which are expected to affect firms' capital structure and to test empirically the relevance of agency cost hypothesis about the determination of capital structure, For these purposes, this paper carried out multiple regression in order to examine whether the factors of agency costs affect significantly the determination of capital structure. The results of empirical analysis are summarrized as follows; First, insider-equity ration has been negatively correlated with capital structure. Second, growth opportunity variabless has been insignificant coefficients with capital structure.