• 호남수학학술지
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• 제46권1호
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• pp.60-69
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• 2024

We consider a special orthonormal basis for the Hardy space of the unit disc to compute the matrix representations of the composition operators with respect to the basis particulary associated to two symbols which are the inverse and the origin symmetry of the Riemann self map in the unit disc, and then we find a certain symmetry of the matrices.

• 한국인쇄학회지
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• 제20권1호
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• pp.146-158
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• 2002

JPEG is good for full color representation but is poor in quality of image because of the small size and the losing compression ways. GIF is a kind of format style made for image - transmission in Compuserve which is a method of PC communication in U. S. A and now is used in world wide web owing to the efficiency of file compression and transmission. But GIF only is used 256 colors, so the images in web has a poorer quality of colors effect to be compared with those of printed catalogues. Also there can be licence problems when the images is used for commercial uses because the possession is Compuserve. The PNG is a way that the total advantages of JPEG and GIF. PNG image file is a more skillful (bitmap display unit), shows a high quality image like TIFF image about, gives superior compression , a 10% to 30% represents full color, 256 color, gray like JPEG. GIF file which uses LZW compression file is a thing which pays licence, In other hands, PNG is free from licence and more skillful image processing method against image error, and it is possible to conserve the color information. Therefore, this treatise is about how various images which are utilized for commercial printings in web, can be made into PNG files about the compression file. And the representation of image by compared the G]U images with JPEG images as well as compression file and the representation of image the superiority of color representation. In addition, 1 check out how much ranges the PNG files are available for electronic publish printing.

• Current Optics and Photonics
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• 제4권3호
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• pp.210-220
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• 2020

Aiming at the problem that the Local Sparse Difference Index algorithm has low accuracy and low efficiency when detecting target anomalies in a hyperspectral image, this paper proposes a Weighted Collaborative Representation and Sparse Difference-Based Hyperspectral Anomaly Detection algorithm, to improve detection accuracy for a hyperspectral image. First, the band subspace is divided according to the band correlation coefficient, which avoids the situation in which there are multiple solutions of the sparse coefficient vector caused by too many bands. Then, the appropriate double-window model is selected, and the background dictionary constructed and weighted according to Euclidean distance, which reduces the influence of mixing anomalous components of the background on the solution of the sparse coefficient vector. Finally, the sparse coefficient vector is solved by the collaborative representation method, and the sparse difference index is calculated to complete the anomaly detection. To prove the effectiveness, the proposed algorithm is compared with the RX, LRX, and LSD algorithms in simulating and analyzing two AVIRIS hyperspectral images. The results show that the proposed algorithm has higher accuracy and a lower false-alarm rate, and yields better results.

• Nuclear Engineering and Technology
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• 제29권5호
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• pp.375-384
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• 1997

Relative power density distributions of the Kori Unit 1 pressurized water reactor are calculated by Monte Carlo modeling with the MCNP code. The Kori Unit 1 core is modeled on a three-dimensional representation of the one-eighth of the reactor in-vessel component with reflective boundaries at 0 and 45 degrees. The axial core model is based on half core symmetry and is divided into four axial segments. Fission reaction density in each rod is calculated by following 100 cycles with 5,000 test neutrons in each cycle after starling with a localized neutron source and ten noncontributing settle cycles. Relative assembly power distributions are calculated from fission reaction densities of rods in assembly. After 100 cycle calculations, the system converges to a k value of 1.00039 $\geq$ 0.00084. Relative assembly power distribution is nearly the same with that of the Kori Unit 1 FSAR. Applicability of the full-scope Monte Carlo simulation in the power distribution calculation is examined by the relative root moan square error of 2.159%.

• 대한토목학회논문집
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• 제10권1호
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• pp.99-108
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• 1990

지형화적 순간단위도 이론을 이용하여 강우-유출 수문곡선을 재현할 수 있는 합성단위도법을 연구하였다. 지형학적 순간단위도는 Gupta등이 제한한 이론을 이용하였고, 응답함수는 2변수 감마분포를 사용하였다. 응답함수의 매개변수결정은 Rosso가 유도한 Horton의 지형법칙에 대한 회귀방정식과 유역지체시간의 저유계수에 대한 상관식을 이용하였다. 유도된 합성단위도의 적용성을 검토하기 위해 한강수계의 평창강과 낙동강수계의 위천유역에 대한 실측치와 비교하였다. 그리고 모멘트법과 불안전 감마함수를 사용한 최소자승법을 이용하여 수문응답의 재현정도를 비교 검토함으로서 본 연구에서 확립된 방법의 적용 타당성을 입증하였다. 분석결과 유도된 합성단위도는 첨두유량, 도달시간 그리고 수분곡선의 실측치에 대한 재현성이 비교적 높았으며, 미계측 유역의 유출해석에 중요한 수단을 제공할 것으로 판단되었다.

• 컴퓨터교육학회논문지
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• 제11권6호
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• pp.53-64
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• 2008

2007년 개정 정보 교육과정은 2010년부터 적용될 예정이지만 교육과정에서 제시된 교육내용의 포괄적인 성격으로 인해 학교 현장의 교수 학습이나 평가 상황에 직접적으로 활용하기에는 한계가 있다. 따라서 새로운 교육과정에 대한 올바른 이해와 학교 현장에서 이루어지는 교수 학습 활동 및 평가 활동의 방향을 제시하기 위한 구체적인 기준과 예시를 제시할 필요가 있다. 본 연구에서는 2007년 개정 정보 교육과정의 '정보의 표현과 관리' 영역에 관한 구체적인 성취기준과 평가기준을 개발하고 그에 따른 평가도구들을 개발하였다. 성취기준은 교육과정상의 소영역을 기준으로 학생의 입장에서 진술하였으며, 평가기준은 상, 중, 하로 구분하여 제사하였다.

• 대한수학교육학회지:학교수학
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• 제13권3호
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• pp.447-468
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• 2011

고등학교 수학교과과정에서 이차곡선에 관련된 단원의 지도는 다른 어떤 단원보다도 연결성이 고려된 지도가 필요한 단원이다. 다시 말해 대수적 접근 방식과 기하적 접근 방식이 동시에 병렬적으로 지도되어야 한다. 특히 대수적 조작력이 미흡한 하위권 학생들에게는 이차곡선에 대한 성질을 역동적으로 표현하는 시각적 표상을 심어주는 기하적 접근 방식이 더욱 중요하다. 이를 위하여 본 연구는 이차곡선의 지도에 있어서 GeoGebra에 기반한 역동적인 시각적 표상의 중요성을 제안하고자 현행 고등학교 '기하와 벡터' 10종의 교과서와 익힘책의 이차곡선 단원 중 포물선에 관련된 부분을 분석하여 시각적 표상을 극대화할 수 있는 지도 방안을 제안하는 실험적 수업을 진행하고 학생들의 표상의 변화를 분석하였다.

• 한국비블리아학회지
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• 제5권1호
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• pp.85-105
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• 1981

Information is an essential factor leading the rapid progress which is one of the distinguished characteristics in modem society. As more information is required and as more is supplied by individuals, governmental units, businesses, and educational institutions, the greater will be the requirement for efficient methods of communication. One possibility for improving the information dissemination process is to use computers. The capabilities of such machine are beginning to be used in the process of Information storage, retrieval and dissemination. An important problems, that must be carefully examined is whether one technique for information retrieval is better for worse than another. This paper examines problem of how to evaluate an information retrieval system. One specific approach is a cost accounting model for use in studying how to minimize the cost of operating a mechanized retrieval system. Through the use of cost analysis, the model provides a method for comparative evaluation between systems. The general cost accounting model of the literature retrieval system being designed by this study are given below. 1. The total cost accounting model of the literature retrieval system. The total cost of the literature retrieval system = (the cost per unit of user time X the amount of user time) + ( the cost per unit of system time X the amount of system time) 2. System cost accounting model system cost = (the pre-search system cost per unit of time X time) + (the search system cost per unit of time X time) + (the post search system cost per unit of time X time) 1) Pre-search system cost per unit of time = cost of channel per unit time + cost of central processing unit per unit time + cost of storage per unit time 2) Search system cost per unit of time = comparison cost + document representation cost. 3) Post-search system cost per unit of time. = cost of channel per unit time + cost of central processing unit per unit time + cost of storage per unit time 3. User cost accounting model Total user cost = [pre-search user cost per unit of time X (time + additional time) ] + [search user cost per unit of time X (time + additional time) ] + [post-search user cost per unit of time X (time + additional time) ].

• 한국전산응용수학회:학술대회논문집
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• 한국전산응용수학회 2003년도 KSCAM 학술발표회 프로그램 및 초록집
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• pp.9-9
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• 2003

Let $\Omega$ be a bounded, open, and polygonal domain in $R^2$ with re-entrant corners. We consider the following Partial Differential Equations: $$(I-\nabla\nabla\cdot+\nabla^{\bot}\nabla\times)u\;=\;f\;in\;\Omega$$, $$n\cdotu\;0\;0\;on\;{\Gamma}_{N}$$, $${\nabla}{\times}u\;=\;0\;on\;{\Gamma}_{N}$$, $$\tau{\cdot}u\;=\;0\;on\;{\Gamma}_{D}$$, $$\nabla{\cdot}u\;=\;0\;on\;{\Gamma}_{D}$$ where the symbol $\nabla\cdot$ and $\nabla$ stand for the divergence and gradient operators, respectively; $f{\in}L^2(\Omega)^2$ is a given vector function, $\partial\Omega=\Gamma_{D}\cup\Gamma_{N}$ is the partition of the boundary of $\Omega$; nis the outward unit vector normal to the boundary and $\tau$represents the unit vector tangent to the boundary oriented counterclockwise. For simplicity, assume that both $\Gamma_{D}$ and $\Gamma_{N}$ are nonempty. Denote the curl operator in $R^2$ by $$\nabla\times\;=\;(-{\partial}_2,{\partial}_1$$ and its formal adjoint by $${\nabla}^{\bot}\;=\;({-{\partial}_1}^{{\partial}_2}$$ Consider a weak formulation(WF): Find $u\;\in\;V$ such that $$a(u,v):=(u,v)+(\nabla{\cdot}u,\nabla{\cdot}v)+(\nabla{\times}u,\nabla{\times}V)=(f,v),\;A\;v{\in}V$$. (2) We assume there is only one singular corner. There are many methods to deal with the domain singularities. We introduce them shortly and we suggest a new Finite Element Methods by using Singular representation for the solution.

• 대한의용생체공학회:의공학회지
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• 제26권4호
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• pp.199-205
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• 2005

When recording single-unit responses from neural systems, a common problem is the accurate detection of spikes (action potentials) in the presence of competing unwanted (noise) signals. While some sources of noise can be readily dealt with through filtering or 'template subtraction' techniques, other sources present a more difficult problem. In particular, noise components introduced by power supplies, which contain harmonics of the power-line frequency, can be particularly troublesome in that they can mimic the shape of the desired spikes. Thus, standard 'template subtraction' techniques or notch-filtering approaches are not appropriate. In this study, we propose the use of a novel template-subtraction scheme that involves estimating the power-line noise waveform and using cross-correlation techniques to subtract them from the recordings. This technique requires two key steps: (1) cross-correlation analysis of each recorded waveform extracts a robust representation of the power-line noise waveform and (2) a second level of cross-correlation to successfully subtract that representation from each recorded waveform. This paper describes this algorithm and provides examples of its implementation using actual recorded waveforms that are contaminated with these noise signals. An improvement (reduction) in the noise level is reported, as are suggestions for future implementation of this strategy.