• Proceedings of the Korean Society For Composite Materials Conference
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• 2003.04a
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• pp.143-146
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• 2003

A finite element based on the efficient higher order zig-zag theory with multiple delaminations Is developed to refine the predictions of frequency and mode shapes. Displacement field through the thickness are constructed by superimposing linear zig-zag field to the smooth globally cubic varying field. The layer-dependent degrees of freedom of displacement fields are expressed in terms of reference primary degrees of freedom by applying interface continuity conditions including delaminated interfaces as well as free hounding surface conditions of transverse shear stresses. Thus the proposed theory is not only accurate but also efficient. This displacement field can systematically handle the number, shape, size, and locations of delaminations. Throught the dynamic version of variational approach, the dynamic equilibrium equations and variationally consistent boundary conditions are obtained. Through the natural frequency analysis and time response analysis of composite plate with multiple delaminations, the accuracy and efficiency of the present finite element are demonstrated. The present finite element is suitable in the predictions of the dynamic response of the thick composite plate with multiple delaminations.

• Bulletin of the Korean Chemical Society
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• v.20 no.6
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• pp.643-647
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• 1999

Hydropalladium carboxylates, formed from π-allylpalladium chloride dimer plus carboxylic acids, have been shown to catalyze cyclization of structurally diverse enediynes to form the corresponding six- or five-membered rings depending upon the reaction conditions. Some enediynes having an Oxygen linker in an appropriate position under the similar condition yielded the corresponding cyclopropanation products in highly stereoselective manner. A study using deuterated formic acid has proven that the alkylpalladium intermediates formed in our conditions were reduced by the pendant formate ligand. The dienediyne 10 yielded only the tricyclic product 12 in 67% yield, although it was expected to frrm the cyclic product 11. All these cyclizations seemed to occur via the corresponding alkylpalladium intermediates I. which could proceed to the corresponding cyclic products depending on the reaction conditions and the substrates. The study using ceuterated formic acid could provide an important information to understand the present cyclization mechanism. Overall the present study could play an important role in developing new synthetic methodologies for constructing complex polycyclic compounds.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.35.3-36
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• 2016

Density and velocity perturbations in scales most relevant for the first galaxy formation are strongly affected by large-scale density perturbations, velocity-divergence perturbations and the baryon-cold dark matter (CDM) streaming velocities. Even at redshifts as high as z~200, this mode-mode coupling imprints a significant impact on the small-scale perturbations, at the wavenumber k >${\sim}100Mpc^{-1}$, as was calculated in our recent work. This implies that cosmological initial conditions based on the usual linear theory is no longer valid in these scales. We present a new cosmological initial condition generator, BCCOMICS, which generates initial conditions for the cold dark matter (CDM) and baryons in scales most relevant for the first galaxy formation. BCCOMICS is based on the linear perturbation theory including the mode-mode coupling terms, and generates cosmological initial conditions for the SPH-basded code GADGET and the AMR-based code ENZO. We also present our preliminary result on the cosmic variance of the first galaxy formation, studied by using BCCOMICS.

• Journal of the Korean Institute of Rural Architecture
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• v.13 no.3
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• pp.29-36
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• 2011

The purpose of this study was analyzing with present conditions and content analysis of the parking area for the handicapped people. The researcher investigate to that establishment ratio, accessibility, the induction and guidance, and safe walking passage security, and proper space of the parking area for the handicapped people was established by lawfully. The results as follows. In spite of the regulation established by law, regulations was not established 40% on region government. The parking area for the handicapped people established Properly consider to the accessibility. But the size and height of the stand-up guide plate of the induction and guidance which corresponds in legal establishment standard of the handicapped people. then this research analyzes problems and suggests alternatives of the facilities.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.2
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• pp.57.4-58
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• 2018

It is interesting to find the best exospheric model that can account for the observed characteristics of the lunar coma and tail simultaneously. Recently, the initial abundances of atomic species near surface are found to be different depending on certain local areas. We will present the influence of different initial conditions of localized sources on the characteristics of the lunar exosphere, and also present time-dependent simulations showing the distributions of atomic species around the lunar coma and the final stage of the lunar tail. Based on our updated 3-D lunar model, we will present resulted physical parameters of the lunar sodium coma and tail.

• KIEAE Journal
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• v.14 no.4
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• pp.97-102
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• 2014

This study has an intention of investigating residential present condition of small households, and analysing the factors which have an influence on the choice of residence as a first step of the efficient plan of group residential facility providing a variety of residential present condition. The study defines the meaning of small households on the basis of statistical data that were presented at the National Statistical Office in order to analyse the factors influencing the choice of residence and investigate residential present condition. And the analysis range target is from 20 to 30 aged groups such as university students, social rookie year, and married couples without children. According to the result of analysing residential actual conditions of small households, The choice of residence has various factors. But the study supposes that it reflects three elements of workplace, University and housing price in the choice of residence. So the study investigated the related data.

• East Asian mathematical journal
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• v.23 no.3
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• pp.313-326
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• 2007

The purpose of education of propositional logic is to understand the basic structure of the mathematics and to improve the logical thinking in normal life. But in the seventh curriculum, some basic terms, for examples $\wedge$ and $\vee$, are not introduced, the proposition $p{\\rightarrow}q$ is not defined properly, and use the wrong term $\Rightarrow$ so that it is difficult to understand the propositional logic. In this paper, we present a suitable content for the propositional logic in high-school mathematical class. We also present a proper definition of the proposition $p{x}{\Rightarrow}q{x}$ without using the notation $\rightarrow$. We finally give proper definitions of necessary conditions, sufficient conditions, and necessary and sufficient conditions.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.405-412
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• 1992

The problem we consider in this paper is more demanding than the problem of input-output linearization with state equivalence recently solved by Cheng, Isidori, Respondek, and Tarn. We request that the MIMO nonlinear system, for which the problem of input-output linearization with state-equivalence is solvable, can be decoupled. In exchange for further requirement like this, our problem produces more usable and informative results than the problem of input-output linearization with state-equivalence. We present the necessary and sufficient conditions for our problem to be solvable. We characterize each of the nonlinear systems satisfying these conditions by a set of parameters which are invariant under the group action of state feedback and transformation. Using this set of parameters, we can determine directly the unique one, among the canonical forms of decouplable and controllable linear systems, to which a nonlinear system can be transformed via appropriate state feedback and transformation. Finally, we present the necessary and sufficient conditions for our problem to be solvable with internal stability, that is, for stable decoupling.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2001.05a
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• pp.56-59
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• 2001

This study for enquete an exact the present conditions museum plan for analyzing barrier free theory. The research is base on the side of consciousness, space and activity the present condition for person of an advanced age and the physically handicapped person. Through the research for purpose of confirm that baker free theory. And also, using for the result i]f this research that for all user. And then, it will be turn out that direct data linked to solve of the realistic subject, so therefore basic course and guide line what was due to point out

• Journal of the Korean Institute of Rural Architecture
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• v.5 no.1
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• pp.1-11
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• 2003

The purpose of this study is to investigate and analyze the present state of elementary school libraries in Daejeon Metropolitan City. For this 50 schools are surveyed by questionnaires on two groups of teachers, those that take charge of school library and those who do not. As a results of this research following issues are emerged. First, the present state of surveyed school libraries is below standard with regard to the amount of books and size and it is required to improve these poor conditions. Second, the space programs are not sufficient to conduct enlarging scope of school libraries, which is conspicuous in spaces for affording librarians, supporting various activities and serving user's convenience. Third, in spite of poor conditions in school library facilities, respondents' satisfaction rate is not so low and there's no obvious demand for diversity of spaces.