• 비파괴검사학회지
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• 제7권1호
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• pp.42-50
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• 1987

Most of significant defects in the pressure boundaries of nuclear power plant we re dispositioned to be monitored periodically every inservice inspection. Due to the difficulty of the defect sizing during operation, it is necessary to develope the continuous flaw monitoring techniques. The Tip Diffraction method, specifically speaking, spot seems to be suitable for flaw monitoring. The optimum conditions of selecting the transducer were 3.5 MHz and 45-57 degree according to compatibility with the defect height. The effective calculation of the defect height was to assume the fact that the incident beam is parallel. This method would be supplemented to ASME method about the defect characterization for the surface flaw.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1998년도 춘계학술대회논문집; 용평리조트 타워콘도, 21-22 May 1998
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• pp.492-497
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• 1998

Thermoacoustic oscillation is a significant problem in cylindrical-type combustors such as common internal combustion engines, industrial furnaces, gas turbine, etc. This kind of low frequency oscillation can give rise to serious troubles such as the destruction of system or producing of a strong noise. Accurate numerical simulation of thermoacoustic phenomena is a complex and challenging problem. Especially, considering the reaction of mixture intensifies the difficulty of analysis. Like as other simulations of the aerodynamics and aeroacoustics, direct computation of thermoacoustic phenomena requires that the Navier-Stokes equations be solved using accurate numerical differentiation and time-marching schemes, with non-reflecting boundary conditions. In this study,, numerical approach aims at qualitative analysis and efficient prediction of problem, not at the development of an accurate scheme. Overally speaking, numerical prediction is reasonably matched with experimental result.

• 대한수학교육학회지:수학교육학연구
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• 제12권3호
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• pp.425-442
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• 2002

One of important topics in mathematics education research is communication. Mathematical communication consists of writing, reading, listening and speaking. But, research on reading has not yet to have a commensurate emphasis, despite important changes that have occurred in the theory and practice of communication. This study is intended to search for reading in school mathematics. First, we explore theories of reading and reading instruction. Second, the factors involved in reading are examined. These factors are learners, texts and teachers. Third, we provide a variety of reading strategies that are reading and enacting strategy, reconstructing strategy, presupposing strategy, becoming an author strategy, sketch to stretch strategy and reading- cooperative learning strategy. They will help students to foster students' mathematical ability as well as reading skill.

• 대한수학회보
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• 제25권2호
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• pp.179-183
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• 1988

In this paper we study a $C^{*}$-dynamical system (A, G, .alpha.) where A is a UHF-algebra, G is a finite abelian group and .alpha. is a *-automorphic action of product type of G on A. In [2], A. Kishimoto considered the case G= $Z_{n}$, the cyclic group of order n and investigated a condition in order that the fixed point algebra $A^{\alpha}$ of A under the action .alpha. is UHF. In later N.J. Munch studied extremal tracial states on $A^{\alpha}$ by employing the method of A. Kishimoto [3], where G is a finite abelian group. Generally speaking, when G is compact (not necessarily discrete and abelian), $A^{\alpha}$ is an AF-algebra and its ideal structure was well analysed by N. Riedel [4]. Here we obtain some conditions for $A^{\alpha}$ to be UHF, where G is a finite abelian group, which is an extension of the result of A. Kishimoto.oto.

• The Journal of the Acoustical Society of Korea
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• 제22권3E호
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• pp.110-112
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• 2003

There have been numerous studies on the enhancement of the noisy speech signal. In this paper, we propose a completely new speech enhancement scheme, that is, a filtering of a dissonant frequency (especially F# in each octave of the tempered scale) based on the fundamental frequency which is developed in frequency domain. In order to evaluate the performance of the proposed enhancement scheme, subjective tests (MOS tests) were conducted. The subjective test results indicate that the proposed method provides a significant gain in audible improvement especially for speech contaminated by colored noise and speaking in a husky voice. Therefore when the filter is employed as a pre-filter for speech enhancement, the output speech quality and intelligibility is greatly enhanced.

• 한국제4기학회지
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• 제1권1호
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• pp.47-67
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• 1987

우리나라 구석기시대에 보편적인 것으로 알려진 동굴입구나 움푹 들어간 바위절벽밑의 바위그늘을 이용한 주거지 유적이 제주도 신석기시대 이후까지 상당한 기간 지속되었음이 발견되었다. 그러나 그후 청동기시대에서 철기시대에 이르러 이러한 주거지는 캠핑지역으로 변한 증거가 있다. 그런데 제주도에는 해안가와 하천에 따라 동굴입구 또는 용암턴넬이 많이 발달하여 화산도로서의 특징이 있으며 이들이 선사시대의 인류에 의하여 사용된 것이 특기할 만하다.

• 인지과학
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• 제14권4호
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• pp.43-51
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• 2003

The present paper is concerned with assessing both communicational skills and grammatical knowledge in three Korean-speaking children with a range in age from 9;11 to 12;2 and in MLU from 1.68 to 2.22. It was found that all three autistic children's speech was largely repetitive and echolalic, unable to consistently interact communicatively on the ongoing joint focus of attention. It was also observed that the more repetitive the child speech was, the more impaired morpho-syntactically it was. Based on these findings, it was speculated that the deficit in joint focus of attention might relate to grammatical development.

• KIEAE Journal
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• 제5권1호
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• pp.59-65
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• 2005

Eco-friendly architecture, generally speaking, is considered as the activity of planting more and designing ponds, therefore many clients and constructors prefer to avoid building so due to initial construction costs. This paper aims to examine the cognition of environmental equipment systems and the applicability of echo-friendly building constructions. We examined the designer's demands of building equipment systems and eco-friendly environment and tried to deduce desirable suggestions for the system. We should solve the fundamentals of economical problems in the construction of eco-friendly buildings and we better think that government should make it a policy to advertise it and to reform the taxation system regarding environment friendly buildings.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.92-95
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• 2001

The dielectric breakdown of epoxy composites used for transformers was experimented and then its data were simulated by Weibull distribution probability. First of all, speaking of dielectric breakdown properties, the more hardener increased the stronger breakdown strength at low temperature because of cross-linked density by the virtue of ester radical. The breakdown strength of specimens with filler was lower than it of non-filler specimens because it is believed that the adding filler forms interface and charge is accumulated in it, therefore the molecular motility is raised and the electric field is concentrated. In the case of filled specimens with treating silane, the breakdown strength become much higher Finally, from the analysis of weibull distribution, it was confirmed that as the allowed breakdown probability was given by 0.1[%], the applied field value needed to be under 21.5 [Mv/cm].

• 한국인지과학회:학술대회논문집
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• 한국인지과학회 2002년도 춘계학술대회
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• pp.72-75
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• 2002

본 연구는 '원인'의 개념과 타동사성에 대한 아동의 민감성이 공대명사 처리에 어떻게 반영되는지에 대해 검토하였다. 한국어뿐만 아니라 여러 언어에서 관찰되었듯이, '원인'은 서술부 중심의 어휘정보 이론에서 이용되는 핵심적인 개념으로서, 타동사와 목적어 사이에 잠재적으로 함유된 '원인'의 정도에 따라 목적어의 생략이 허용된다. 본 연구는 세명의 한국 아동 (0;10-3;7)의 발화자료를 토대로 한국어의 공대명사화 구조를 검토하여 다음과 같은 관찰을 하였다. 한국아동은 습득 초기에는 주로 옛정보, 새정보 등의 담화화용적 제약에 따른 발화를 하지만, 3세경부터는 동사의 습득양상이 점차적으로 다양해지는데, 이때부터는 논항의 생략과 동사의 타동사성과 상호관계를 보인다.