• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
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• pp.137-142
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• 2004

In this paper, we propose a new scheme for geometry coding of three-dimensional (3-D) mesh models using a fixed spectral basis. In order to code the mesh geometry information, we generate a fixed spectral basis using the dual graph derived from the 3-D mesh topology. After we partition a 3-D mesh model into several independent sub-meshes to reduce coding complexity, the mesh geometry information is projected onto the generated orthonormal bases which are the eigenvectors of the Laplacian matrix of the 3-D mesh. Finally, spectral coefficients are coded by a quantizer and a variable length coder. The proposed scheme can not only overcome difficulty of generating a fixed spectral basis, but also reduce coding complexity. Moreover, we can provide an efficient multi-resolution representation of 3-D meshes.

• Journal of electromagnetic engineering and science
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• 제17권2호
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• pp.51-56
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• 2017

This study proposes a modeling process of equivalent terrains to reduce the computational load and time of a full-wave electromagnetic (EM) simulation. To verify the suitability of the proposed process, an original terrain model with a size of $3m{\times}3m$ is equivalently quantized based on the minimum range resolution of a radar, and the radar image of the quantized model is compared with that of the original model. The results confirm that the simulation time can be reduced from 407 hours to 162 hours without a significant distortion of the radar images, and an average estimation error of the quantized model (20.4 mm) is similar to that of the original model (20.3 mm).

• Journal of Information Processing Systems
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• 제15권3호
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• pp.492-499
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• 2019

HEVC is the high efficiency video coding standard, which provides better coding efficiency contrasted with the other video coding standard. But at the same time the computational complexity increases drastically. Thirty-five kinds of intra-prediction modes are defined in HEVC, while 9 kinds of intra prediction modes are defined in H.264/AVC. This paper proposes a fast rough mode decision (RMD) algorithm which adopts the smoothness of the up-reference pixels and the left-reference pixels to decrease the computational complexity. The three step search method is implemented in RMD process. The experimental results compared with HM13.0 indicate that the proposed algorithm can save 39.7% of the encoding time, while Bjontegaard delta bitrate (BDBR) is increased slightly by 1.35% and Bjontegaard delta peak signal-to-noise ratio (BDPSNR) loss is negligible.

• ETRI Journal
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• 제45권4호
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• pp.557-569
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• 2023

Traditional deterministic channel modeling is accurate in prediction, but due to its complexity, improving computational efficiency remains a challenge. In an alternative approach, we investigated a multilayer artificial neural network (ANN) to predict large-scale and small-scale channel characteristics in metro tunnels. Simulated high-precision training datasets were obtained by combining measurement campaign with a ray tracing (RT) method in a metro tunnel. Performance on the training data was used to determine the number of hidden layers and neurons of the multilayer ANN. The proposed multilayer ANN performed efficiently (10 s for training; 0.19 ms for prediction), and accurately, with better approximation of the RT data than the single-layer ANN. The root mean square errors (RMSE) of path loss (2.82 dB), root mean square delay spread (0.61 ns), azimuth angle spread (3.06°), and elevation angle spread (1.22°) were impressive. These results demonstrate the superior computing efficiency and model complexity of ANNs.

• 과학교육연구지
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• 제37권2호
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• pp.323-337
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• 2013

이 연구의 목적은 자유탐구 활동에서 나타난 중학교 2학년 과학 영재 학생들의 과학적 추론 능력을 알아보는 것이다. 과학영재들이 과학자가 지식을 얻는 과정과 유사한 자유탐구 활동을 실시할 때 어떠한 과학적 추론과정을 거쳐 탐구하고 있으며 과학적 추론 능력이 어느 정도인지를 확인하고 분석하는 것은, 학생 지도에 있어서 교육적 시사점을 줄 수 있다. 이를 위하여 정선희 등(2011)이 번역한 Dolan과 Grady(2010)의 CSRI Matrix를 이용하여 추론 복잡성을 분석하였으며, 추론 복잡성이 높을수록 과학자가 지식을 얻는 과학적 추론 과정과 비슷하다. 연구 결과, 자유탐구의 과정별로 추론 복잡성 단계는 다양하게 분포하였다. 특히 의문 생성 과정과 연구 의문과 자료 연결 과정은 5개 팀이 모두 비교적 높은 추론 복잡성 단계를 나타낸 반면, 예비가설 생성과정 변인 선택 실험의 한계나 결점 고려 등은 비교적 낮은 단계를 나타내었다. 그리고 의사소통 및 연구 결과 방어는 가장 다양한 추론 복잡성 단계 분포를 나타내었다.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1993년도 춘계공동학술대회 발표논문 및 초록집; 계명대학교, 대구; 30 Apr.-1 May 1993
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• pp.5-5
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• 1993

• 대한전자공학회논문지TC
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• 제46권10호
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• pp.8-13
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• 2009

정합필터(matched filter)는 백색잡음 환경에서 출력 첨두 신호전력 대 평균 잡음전력의 비를 최대화하는 최적 탐지기이다. 하지만 비백색 잡음 환경에서는 정합필터를 이용하여 최적 탐지성능을 얻을 수 없다. 따라서 정합필터 이전에 백색화 과정을 수행하는 선백색화 정합필터(pre-whitening matched filter) 탐지기가 사용된다. 그리고 이것의 성능은 백색화 과정에 사용되는 비백색 잡음모델의 추정 정확성에 크게 영향을 받는다. 성능을 높이기 위해서는 정확한 잡음모델을 추정해야 하지만 이는 계산 복잡도를 많이 증가시킨다. 그러므로 본 논문에서는 기존 선백색화 정합필터 탐지기와 유사한 복잡도에서는 우수한 성능을 보이며, 유사한 성능에서는 낮은 복잡도를 보이는 스펙트럼 기반의 탐지기를 제안한다. 그리고 제안된 탐지기의 성능과 복잡도를 기존 탐지기와 비교하고 이를 분석한다.

• 인지과학
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• 제34권1호
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• pp.1-20
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• 2023

본 연구에서는 시각적 요인에 따라 한글 단어 재인에 미치는 공간주의의 영향을 살펴보았다. 시각적 요인에 따라 공간주의의 영향이 다르게 나타나는지 살펴보기 위해 단어의 시각적 복잡성(실험 1)과 단어의 밝기 대비(실험 2)를 조작하였다. 단어의 복잡성에 따라 받침이 있는 조건과 받침이 없는 조건으로 나뉘었고, 단어의 대비에 따라 대비가 높은 조건과 대비가 낮은 조건으로 나뉘었다. 어휘판단과제를 사용하여 공간단서가 표적 위치에 주어지는 경우(타당 시행)와 표적 위치에 주어지지 않는 경우(비타당 시행) 간의 수행 차이를 단서효과로 계산하여 주의의 영향을 살펴보았다. 실험 결과, 단어의 복잡성에 따라서는 단서효과가 유사하게 나타났으므로, 공간주의의 영향은 복잡성에 의해 달라지지 않는 것으로 해석되었다. 단어의 대비에 따라서는 고대비 조건에 비해 저대비 조건에서 단서효과가 크게 나타났다. 대비가 낮을 때 공간주의의 영향이 더 커지는 것은 자극의 신호를 강화시키는 공간주의의 기제로 설명되었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권6호
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• pp.2271-2288
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• 2015

The emerging high efficiency video coding (HEVC) standard adopts the quadtree-structured transform unit (TU) in the residual quadtree (RQT) coding. Each TU allows to be split into four equal sub-TUs recursively. The RQT coding is performed for all the possible transform depth levels to achieve the highest coding efficiency, but it requires a very high computational complexity for HEVC encoders. In order to reduce the computational complexity requested by the RQT coding, in this paper, we propose a fast TU size decision method incorporating an adaptive maximum transform depth determination (AMTD) algorithm and a full check skipping - early termination (FCS-ET) algorithm. Because the optimal transform depth level is highly content-dependent, it is not necessary to perform the RQT coding at all transform depth levels. By the AMTD algorithm, the maximum transform depth level is determined for current treeblock to skip those transform depth levels rarely used by its spatially adjacent treeblocks. Additionally, the FCS-ET algorithm is introduced to exploit the correlations of transform depth level between four sub-CUs generated by one coding unit (CU) quadtree partitioning. Experimental results demonstrate that the proposed overall algorithm significantly reduces on average 21% computational complexity while maintaining almost the same rate distortion (RD) performance as the HEVC test model reference software, HM 13.0.

• International Journal of Computer Science & Network Security
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• 제23권12호
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• pp.187-193
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• 2023

Large software systems are being produced with a noticeably higher level of quality with component-based software engineering (CBSE), which places a strong emphasis on breaking down engineered systems into logical or functional components with clearly defined interfaces for inter-component communication. The component-based software engineering is applicable for the commercial products of open-source software. Software metrics play a major role in application development which improves the quantitative measurement of analyzing, scheduling, and reiterating the software module. This methodology will provide an improved result in the process, of better quality and higher usage of software development. The major concern is about the software complexity which is focused on the development and deployment of software. Software metrics will provide an accurate result of software quality, risk, reliability, functionality, and reusability of the component. The proposed metrics are used to assess many aspects of the process, including efficiency, reusability, product interaction, and process complexity. The details description of the various software quality metrics that may be found in the literature on software engineering. In this study, it is explored the advantages and disadvantages of the various software metrics. The topic of component-based software engineering is discussed in this paper along with metrics for software quality, object-oriented metrics, and improved performance.