• Journal of KIISE:Databases
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• v.31 no.3
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• pp.331-339
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• 2004

XML has got to be a new standard for data representation and exchanging by its many good points, and the core part of many new researches and emerging technologies. However, the self-describing characteristic, which is one of XML's good points, caused the spreading of XML documents with different structures, and so the need of the research for the effective XML-document search has been proposed. This paper is for the analysis of the problem in BitCube, which is a bitmap indexing that shows high performance grounded on its fast retrieval. In addition, to resolve the problem of BitCube, we did design and implement xPlaneb(XML Plane Web) which it a new 3-dimensional bitmap indexing made of linked lists. We propose an effective information retrieval technique by replacing BitCube operations with new ones and reconstructing 3-dimensional array index of BitCube with effective nodes. Performance evaluation shows that the proposed technique is better than BitCube, as the amount of document increases, in terms of memory consumptions and operation speed.

• Journal of Aerospace System Engineering
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• v.7 no.3
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• pp.20-25
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• 2013

In case of cube satellite, it is difficult to realize the same performance as commercial satellite due to its highly restricted unit accommodation space. To maximize the performance of the cube satellite, design concept considering the multi-function of satellite is required. In this paper, mechanism design of cube satellite which is applicable for the holding and release of multi-deployable structures has been proposed and investigated. In addition, a switch mechanism design for the autonomous system operation just after the cube satellite separation from P-POD has also been proposed. The effectiveness of the mechanism design for holding and release of multi-deployable structures has been demonstrated by EM test of the holding and release mechanism.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.650-653
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• 2002

In this paper, a methodology to assess machine tool errors quickly is suggested using a touch probe and a cube array artifact. Parameterized error models derived are expressed of model coefficient vectors and backlash errors to be determined. To determine the unknown model coefficient vectors, a cube array artifact is proposed. Considering CMM measurement data of cube vertex coordinates. error vectors for all axes ate obtained and used to complete the error model. Some simulation results show that the suggested error model can follow the true values within 10$\mu\textrm{m}$. To verify the error model, a circular part with two concentric circles is measured and simulated. The results show that the differences between CMM and OMM radius errors are smaller than 15$\mu\textrm{m}$.

• Journal of computational fluids engineering
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• v.13 no.1
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• pp.57-62
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• 2008

Laminar flows over a cube and a cuboid (cube extended in the streamwise direction) are numerically investigated for the Reynolds numbers between 50 and 350. First, vortical structures behind a cube and lift characteristics are scrutinized in order to understand the variation in vortex shedding characteristics with respect to the Reynolds number. As the Reynolds number increases, the flow over a cube experiences the steady planar-symmetric, unsteady planar-symmetric, and unsteady asymmetric flows. Similar to the sphere wake, the planar-symmetric flow over a cube can be divided into two different regimes: single-frequency regime and multiple-frequency regime. The former has a single frequency due to regular shedding of vortices with the same strength in time, while the latter has multiple frequency components due to temporal variation in the strength of shed vortices. Second, the effect of the length-to-height ratio of the cuboid on the flow characteristics is investigated for the Reynolds number of 270, at which planar-symmetric vortex shedding takes place behind a cube. With the ratio smaller than one, the flow over the cuboid becomes unsteady asymmetric flow, whereas it becomes steady flow for the ratios greater than one. With increasing the ratio, the drag coefficient first decreases and then increases. This feature is related to the flow reattachment on the side faces of the cuboid.

• Communications of Mathematical Education
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• v.25 no.1
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• pp.207-219
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• 2011

The purpose of this article is to study characteristics of diabolical cube in geometric point of view, and to present educational materials and direction for efficient diabolical cube activities in gifted education upon systematical analysis of methods of finding solutions. We can apply inclusion-exclusion Method to find all possible combination of solutions in diabolical cube activities not as trial-and-error method but as analytical method. Through teacher's questions and problem posing in activities using diabolical cube, we systematically came up with most solution and case of all possible combinations be solution in classifying properties of pieces and combining selected pieces.

• Computers and Concrete
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• v.9 no.2
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• pp.81-97
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• 2012

This paper presents development of double-K fracture model for the split-tension cube specimen for determining the unstable fracture toughness and initial cracking toughness of concrete. There are some advantages of using of split-tension cube test like compactness and lightness over the existing specimen geometries in practice such as three-point bend test, wedge splitting test and compact tension specimen. The cohesive toughness of the material is determined using weight function having four terms for the split-tension cube specimen. Some empirical relations are also suggested for determining geometrical factors in order to calculate stress intensity factor and crack mouth opening displacement for the same specimen. The results of double-K fracture parameters of split-tension cube specimen are compared with those obtained for compact tension specimen. Finally, the influence of the width of the load-distribution of split-tension cube specimen on the double-K fracture parameters for laboratory size specimens is investigated. The input data required for determining double-K fracture parameters for both the specimen geometries are obtained using well known version of the Fictitious Crack Model.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.743-746
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• 2006

In this paper, we propose and analyze a new parallel computer topology, called the Fibonacci posterorder circulants. It connects ${\Large f}_x,\;n{\geq}2$ processing nodes, same the number of nodes used in a comparable Fibonacci cube. Yet its diameter is only ${\lfloor}\frac{n}{3}{\rfloor}$ almost one third that of the Fibonacci cube. Fibonacci cube is asymmetric, but it is a regular and symmetric static interconnection networks for large-scale, loosely coupled systems. It includes scalability and Fibonacci cube as a spanning subgraph.

• Journal of the Korean Data and Information Science Society
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• v.14 no.1
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• pp.37-44
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• 2003

One of the characteristics of both on-line analytical processing(OLAP) applications and decision support systems is to provide aggregated source data. The purpose of this study is to discuss on the aggregation of multi-dimensional data. In this paper, we (1) examine the SQL aggregate functions and the GROUP BY operator, (2) introduce the Data Cube and MDX, (3) present an example for the practical usage of the Data Cube and MDX using sample data.

• Communications of Mathematical Education
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• v.13 no.2
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• pp.765-773
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• 2002

정육면체 27개를 면끼리 붙여서 7개의 조각을 만들어, 이것을 조합하여 3${\times}$3${\times}$3 정육면체가 되도록 하는 퍼즐로 소마큐브(Soma Cube)가 많이 알려져 있다. 이런 입체퍼즐은 공간지각력과 문제해결능력을신장시켜서 창의력을 키우는 데 매우 효과적이므로, 교육적 소재로서 수업에 활용하면 좋다. 이 웍샵에서는 소마큐브와 같은 원리를 갖지만 조각의 모양이 전혀 다른 조이큐브(Joy Cube)와 펀큐브(Fun Cube, Diabolic Cube)를 직접 만들어서, 이를 수업에 활용하는 방법을 소개하려고 한다. 조이큐브는 초등학교 고학년, 펀큐브는 전학년에서 활용이 가능하다.

• Proceedings of the Membrane Society of Korea Conference
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• 2008.05a
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• pp.228-230
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• 2008