• 대한전자공학회논문지SP
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• 제41권5호
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• pp.143-152
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• 2004

본 논문에서는 칼라영상 각 채널에 대한 인간시각 특성이 다르다는 것을 이용하여, 워터마킹의 강인성과 화질열화에 중요한 영향을 미치는 Scaling값을 구하는 알고리듬을 제안한다. 또한, 칼라영상이 다채널 영상임을 이용하여, 상관도와 임계값의 차이가 최대가 되는 경우를 선택하여 워터마크를 삽입하는 선택적 워터마킹 알고리듬을 제안한다. 제안된 알고리듬을 통하여 동일한 화질열화의 조건 아래에서 보다 향상된 강인성을 얻을 수 있다.

• 한국화재소방학회논문지
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• 제24권6호
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• pp.145-152
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• 2010

실규모 ISO 9705 표준 화재실에서 환기부족 화재를 대상으로 연소효율 개념에 대한 검토가 수행되었다. 특히 구획 외부에서 측정되는 총괄연소효율과 구획 내부의 고온 상층부에서 측정된 국부연소효율의 개념을 비교.검토하였다. 연료로는 다양한 범위의 연소열과 그을음 생성량을 갖도록 헵탄, 톨루엔 및 이소프로판올이 사용되었다. 주요 결과로서, 총괄연소효율은 총괄당량비 증가에 따라 비교적 선형적으로 감소한다. 반면에 국부연소효율은 총괄당량비 증가에 따라 2차 곡선의 형태로 크게 감소됨을 확인하였다. 위 결과를 통해 국부연소효율에 대한 정보는 구획 내부의 화재현상을 이해하는데 매우 유용한 변수임을 알 수 있었다. 또한 국부연소효율은 구획화재에 대한 상사과정에서 중요한 변수로 사용될 수 있음을 논의하였다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.343-346
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• 2002

Toward more accurate determination of the water cycle in association with climate variability and change as well as baseline data on the impacts of this variability on water resources, the Coordinated Enhanced Observing Period (CEOP) was launched on July 1,2001. The preliminary data period, EOP-1, was implemented from July to September in 2001. The first annual enhanced observing period, EOP-3, is going to start on October 1,2002. CEOP is seeking to achieve a database of common measurements from both in situ and satellite remote sensing, model output, and four-dimensional data analyses (4DDA; including global and regional reanalyses) for a specified period. In this context a number of carefully selected reference stations are linked closely with the existing network of observing sites involved in the GEWEX Continental Scale Experiments, which are distributed across the world. The initial step of CEOP is to develop a pilot global hydro-climatological dataset with global consistency under the climate variability that can be used to help validate satellite hydrology products and evaluate, develop and eventually predict water and energy cycle processes in global and regional models. Based on the dataset, we will address the studies on the inter-comparison and inter-connectivity of the monsoon systems and regional water and energy budget, and a path to down-scaling from the global climate to local water resources, as the second step.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제15권11호
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• pp.801-805
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• 2009

하드웨어 기반 동적 전압 및 주파수 제어 시스템은 전역 비동기 지역 동기 시스템 설계 방식을 이용하여 동종의 멀티 코어 혹은 이종의 멀티 코어 시스템을 저전력으로 설계하기 위한 핵심 기술 중의 하나이다. 본 논문에서 하드웨어 기반 동적 주파수 제어 시스템의 FPGA 프로토타입 설계를 위해서 동적 주파수 제어기를 제안하고, 이를 FIFO 기반 멀티코어를 이용한 소프트웨어 정의 무선 설계와 네트워크 온 칩 기반의 하드웨어 HPEG2 인코더 설계에 적용하였다. 기존의 단일 주파수 시스템에 비해서 소프트웨어 정의 무선 설계의 경우 성능이 5.9% 하락하였지만, 전력소모는 78% 감소하였다. MPEG2 인코더 설계의 경우에 성능은 0.36% 하락하고 전력소모는 29.1% 감소하였다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2011년도 정기 학술대회
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• pp.278-281
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• 2011

The global coordinates generated from Isomap algorithm provide a simple way to analyze and manipulate high dimensional observations in terms of their intrinsic nonlinear degrees of freedom. Thus, Isomap can find globally meaningful coordinates and nonlinear structure of complex data sets, while neither principal component analysis (PCA) nor multidimensional scaling (MDS) are successful in many cases. It is demonstrated that the adapted Isomap algorithm successfully enhances the quality of pattern classification for damage identification in various numerical examples.

• 대한수학회지
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• 제56권4호
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• pp.1001-1016
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• 2019

We are concerned with optimization methods for the $L^2$-Wasserstein least squares problem of Gaussian measures (alternatively the n-coupling problem). Based on its equivalent form on the convex cone of positive definite matrices of fixed size and the strict convexity of the variance function, we are able to present an implementable (accelerated) gradient method for finding the unique minimizer. Its global convergence rate analysis is provided according to the derived upper bound of Lipschitz constants of the gradient function.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송∙미디어공학회 2019년도 추계학술대회
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• pp.188-190
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• 2019

Long-term global motion compensation (LT-GMC) was designed to compensate camera motion effectively. The LT-GMC warps a reference picture according to an estimated affine/homography model and stores it in its decoded picture buffer for long-term reference. Most previous works on LT-GMC have focused on improving quality of the warped picture, however, there has been only little consideration on the overhead of its motion coding. In this paper, we address this problem and propose a method, namely Scaling Predictor, to reduce the motion coding overhead for LT-GMC. Our experiment has shown BD-Rate reduction of 1.40% over conventional LT-GMC scheme by applying the proposed method.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.672-676
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• 2003

Recently, the importance of ship vibration is emerging due to the large scaling, high speed and lightning of ship. For pleasantness in a cabin, shipbuilders ask for strict vibration criteria and the degree of vibration level at a deckhouse became an important condition for taking order from customers. This study conducted optimum design to attenuate vibration level of a deckhouse to solve above problems. New method was implemented, that is NASTRAN external call type independence optimization method. The merit of this method is global searching after setting various object functions and design variables. The global optimization algorithm used here is R-Tabu search method, which has fast converging time and searching various size domains. By modeling similar type to ship structure, validity of the suggested method was investigated.

• Journal of Information Processing Systems
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• 제7권1호
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• pp.85-92
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• 2011

This paper shows an effective partitioning of static global row/column buses for tightly coupled 2D mesh-connected small processor arrays ("mesh", for short). With additional O(n/m (n/m + log m)) time slowdown, it enables the mesh of size $m{\times}m$ with static row/column buses to simulate the mesh of the larger size $n{\times}n$ with reconfigurable row/column buses ($m{\leq}n$). This means that if a problem can be solved in O(T) time by the mesh of size $n{\times}n$ with reconfigurable buses, then the same problem can be solved in O(Tn/m (n/m + log m)) time on the mesh of a smaller size $m{\times}m$ without a reconfigurable function. This time-cost is optimal when the relation $n{\geq}m$ log m holds (e.g., m = $n^{1-\varepsilon}$ for $\varepsilon$ > 0).

• 제어로봇시스템학회논문지
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• 제12권6호
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• pp.561-567
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• 2006

This paper deals with a fuzzy controller using IA(Immune Algorithm) for Trajectory Tracking of 2-DOF WMR(Wheeled Mobile Robot). The global inputs to the WMR are reference position and reference velocity, which are time variables. The global output of WMR is a current position. The tracking controller makes position error to be converged 0. In order to reduce position error, a compensation velocities on the track of trajectory is necessary. Therefore, a FIAC(Fuzzy-IA controller) is proposed to give velocity compensation in this system. Input variables of fuzzy part are position errors in every sampling time. The output values of fuzzy part are compensation velocities. IA are implemented to adjust the scaling factor of fuzzy part. The computer simulation is performed to get the result of trajectory tracking and to prove efficiency of proposed controller.