• 한국초등과학교육학회지:초등과학교육
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• 제30권1호
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• pp.1-9
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• 2011

The purpose of this study was to analyze elementary school teachers' teaching style and elementary school students' science anxiety according to teachers' teaching styles for science class. Data were gathered through the teaching style test and the science anxiety test. The teaching style test was taken in 293 elementary school teachers and the science anxiety test was taken in 1,523 elementary school students. The results were as followings: First, elementary school teachers' teaching style for science class were most in provider, expert and least in enabler. Second, elementary school students' science anxiety according to elementary school teachers' teaching style for science class were highest in facilitator and lowest in Enablers. There were significantly differences in science anxiety according to the teaching styles in elementary school. Third, elementary school students' science anxiety increased as grade goes up.

• 천문학회보
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• 제38권2호
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• pp.58.1-58.1
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• 2013

The main idea of the Alcock-Paczynski (AP) test is that, if we use a wrong distance-redshift relation to infer the shape of a spherical object in the Universe, this object may look non-spherical. To probe the cosmic expansion history through the AP test, the key point is to find something which is known as spherical in the Universe. We propose two possible ways applying the AP test to the large scale structure (LSS): 1) Based on the observed galaxies or quasars, one built up the beta-skeleton tracing the LSS, and investigating the inhomogeneity of the connections; 2) One reconstructs the smoothed density-contrast gradient field based on LSS observations, and investigating the inhomogeneity of the gradient vectors. Compared with some existed methods probing AP effect through 2-point correlation function, galaxy pairs, or voids, our methods have various advantages: 1) The information of both the high and low dense regions of the LSS are taken into account. 2) The redshift space distortion as the main contamination to the AP effect can be easily removed.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.1455-1458
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• 2007

Vibration characteristics of concrete slabs were investigated using a 1:10 scale model and finite element method. A 1:10 scale model of a test building with 150 and 200mm slab thicknesses was made of acrylic materials. Modal test was conducted to investigate mode shape and modal frequencies. Results show that the mode shapes of two slabs with different thickness are similar each other, whereas natural frequency is different. Through modal analysis using FEM, it was revealed that both mode shapes and natural frequencies calculated from the FEM model are similar to those of the scale model measurement. It was also found that natural frequencies increased with increment of the slab thickness.

• 전자공학회논문지C
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• 제35C권2호
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• pp.10-21
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• 1998

In this paper, we analyze the problems of conventional and previous mehtod on delay test method in IEEE 1149.1. To solve them, we propose two kinds of delay test architectures. One is called ARCH-C, is for combinatonal circuit, and the other is ARCH-S, for clocked sequential circuit. ARCH-C is able to detect delay defect of 0.5 $T_{tck}$ or 1 $T_{tck}$ size. And ARCH-C have a fixed and small amount of hardware overhead, on the contrary preious method has a hardware overhead on the dependent of CUT. This paper discusses weveral problems of Delay test on IEEE 1149.1 for clocked sequential circuit. We suggest the method called ARCH-S, is based on a clock counting technique to generate continuous clocked input of CUT. the simulation results ascertain the accurate operation and effectiveness of the proposed architectures.res.

• 상하수도학회지
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• 제28권1호
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• pp.73-81
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• 2014

One-dimensional flux theory (1DFT) is conventionally used for design of secondary clarifier of wastewater treatment plant. However, the 1DFT cannot describe turbulence, density current, shape parameters of the clarifier. In this study, we optimized the configurations of influent guide baffle and effluent baffle through the simulation using computational fluid dynamics (CFD) and its verification by particle image velocity (PIV) test. The energy dissipating inlet (EDI) without influent guide baffle ($0^{\circ}$) showed the best efficiency for minimizing downward velocity under the center well of the clarifier. The lowest velocity distribution around the effluent weir region could be obtained with the McKinney baffle (EB-2). The performances of the influent and effluent baffles were clearly verified by PIV test results.

• Communications for Statistical Applications and Methods
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• 제2권1호
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• pp.112-121
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• 1995

Let $p_1$ and $p_2$ be the proportions of two populations. To test the hypothesis $H_0 : p_1 = p_2$, we usually use the $x^2$ statistic, the large sample binomial statistic Z, and the Generalized Likelihood Ratio statistic-2log $\lambda$developed based on different mathematical rationale, respectively. Since testing the above hypothesis is equivalent to testing whether two populations follow the common Bernoulli distribution, one may also test the hypothesis by comparing 1 with the ratio of each density estimate and the hypothesized common density estimate, called comparison density, which was devised by Parzen(1988). We show that the above traditional test statistics ate actually estimating the measure of distance between the true densities and the common density under $H_0$ by representing them with the comparison density.

• 한국구조물진단유지관리공학회 논문집
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• 제1권2호
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• pp.115-122
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• 1997

Although most bridge foundations are usually constructed by Caisson, terrain difficulties sometimes bring about constructing bridge foundations by Jacket piles. This study investigated the dynamic characteristics of Caisson and Jacket by testing the impact applied to actual bridge foundations. The test result showed that the damping ratio of the foundation constructed by Jacket and Caisson were measured 1-2% and 3-6%, respectively. Considering the lateral deflection measured by the impact test, the rigidity of foundations constructed by Jacket was assessed about 1/5 - 1/6 of those constructed by Caisson. It implies that designing bridge foundations should include and reflect the dynamic analysis of bridge foundation.

• 대한본초학회지
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• 제25권1호
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• pp.1-7
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• 2010

Objectives : We investigated genetic toxicity of HMCO5 in relation to chromosome aberration test on Cultured Chinese Hamster Lung (CHL) in the presence and absence of S-9 mix. Methods : Experimental groups were divided into two groups: with S-9mix (+S) or without S-9 mix (-S). -S group was also divided 2 series by treatment hours (6 hr: 6-S; or 24 hr; 24-S). Each group treated with vehicle only (complete culture medium), HMCO5 (1,250, 2,500, $5,000\;{\mu}g/ml$), and cyclophosphamide monohydrate (CPA) and ethylmethanesulfonate (EMS), respectively. Results : HMC05 did not show any aberrant metaphase. However, there were significant (p < 0.01) aberrant metaphases with CPA in S+ and with EMS in S-. Conclusions : These results indicate that HMC05 formula does not show any toxicity in chromosome aberration test.

• Nuclear Engineering and Technology
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• 제30권5호
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• pp.424-434
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• 1998

RELAP5/Mod3.1 code was assessed with the semiscale experiment S-NC-3, and S-NC-4, which simulated the two-phase natural circulation and reflux condensation for the SBLOCA of PWR, respectively . Test S-NC-3 and S-NC-4 calculation results showed that RELAP5/Mod3.1 quite well describes the influence of steam generator secondary side heat transfer degradation on both two-phase natural circulation and reflux condensation. A comparison between the calculated and measured two-phase mass flow rate in test S-NC-3 shows good agreement for primary mass inventory more than 92%. And RELAP5/Mod3.1 have a good mass flow rate prediction capability for the transient such as S-NC-4 except some flow oscillations. The reflux flow rate for S-NC-4 test is under predicted, and the overall results verify that the correct prediction of the reduced liquid level appears to be required for the correct calculation of the overall phenomena.

• Journal of Information Processing Systems
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• 제1권1호
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• pp.75-78
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• 2005

Although many tests for stabilization of the software have been done, vulnerability test for a system run by combination of the software of various products has not been conducted enough. This has led to increased threats and vulnerability of system. Especially, web-based software system, which is public, has inherent possibility of exposure to attacks and is likely to be seriously damaged by an accident. Consequently, comprehensive and systematic test plans and techniques are required. Moreover, it is necessary to establish a procedure for managing and handling the results of vulnerability test. This paper proposes vulnerability test plans and designs for implementing automated tools, both of which can be complied with on web-based software systems.