• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.2
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• pp.355-363
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• 2011

Recently, as one of several methods to improve the performance of DVC(Distributed Video Coding) system, many research works are focusing on the iterative refinement of side information. Most of the conventional techniques are mainly based on the relationship between the reconstruction level and side information, or the vector median filtering of motion vectors, but, their performance improvements are restricted. In order to overcome the performance limit of the conventional schemes, in this paper, a side information generation scheme is designed by measuring the block-cost estimation. Then, by adaptively selecting the compensation mode using the received bit-plane information, we propose a block-adaptive iterative refinement which is efficient for non-symmetric moving objects. Computer simulations show that, by using the proposed refinement method, the performance can be improved up to 0.2 dB in rate-distortion.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.43 no.5 s.311
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• pp.1-11
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• 2006

This paper presents a digital auto-focusing method using a priori estimated point-spread-functions (PSF) database. The proposed algorithm efficiently removes out-of-focus blur in a degraded input image by selecting the optimal PSF from the database. The database consists of optical characteristics of image formation system. The PSF selection Process is performed based on a novel focusing measure. The proposed method includes a spatially adaptive filter for removing both noise and ringing artifacts. Experimental results show that the proposed method efficiently removes out-of-focus blur using significantly reduced computational load compared with the existing method.

• Journal of Digital Contents Society
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• v.13 no.2
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• pp.159-167
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• 2012

Eye tracking technology tracks human eyes movements to understand user's intention. This technology has been improving slowly and should be used for a variety of occasions now. For example, it enables persons with disabilities to operate a computer with their eyes. This article will show a typical implementation of an eye tracking system for persons with disabilities, after introducing the design principles and specific implementation details of an eye tracking system. The article discussed the realization of self-adapting regulation algorithm in detail. The self-adapting algorithm is based on feedback signal controlling the lens movements to realize automatic focus, and to get a clear eyes image. This CCD camera automatic focusing method has self-adapting capacity for changes of light intensity on the external environment. It also avoids the trouble of manual adjustment and improves the accuracy of the adjustment.

• IMMUNE NETWORK
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• v.9 no.4
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• pp.115-121
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• 2009

Natural killer (NK) cells play key roles in innate and adaptive immune defenses. NK cell responses are mediated by two major mechanisms: the direct cytolysis of target cells, and immune regulation by production of various cytokines. Many previous reports show that the complex NK cell activation process requires de novo gene expression regulated at both transcriptional and post-transcriptional levels. Specialized un-translated regions (UTR) of mRNAs are the main mechanisms of post-transcriptional regulation. Analysis of posttranscriptional regulation is needed to clearly understand NK cell biology and, furthermore, harness the power of NK cells for therapeutic aims. This review summarizes the current understanding of mRNA metabolism during NK cell activation, focusing primarily on post-transcriptional regulation.

• International Journal of Fluid Machinery and Systems
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• v.8 no.3
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• pp.209-219
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• 2015

A robust multi-fidelity optimization methodology has been developed, focusing on efficiently handling industrial runner design of hydraulic Francis turbines. The computational task is split between low- and high-fidelity phases in order to properly balance the CFD cost and required accuracy in different design stages. In the low-fidelity phase, a physics-based surrogate optimization loop manages a large number of iterative optimization evaluations. Two derivative-free optimization methods use an inviscid flow solver as a physics-based surrogate to obtain the main characteristics of a good design in a relatively fast iterative process. The case study of a runner design for a low-head Francis turbine indicates advantages of integrating two derivative-free optimization algorithms with different local- and global search capabilities.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.213-216
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• 2005

Active control method is applied to a flexible beam excited by a shock impulse by focusing on reducing the residual vibrations after the shock input. It is assumed that the shock input can be measured and is always occurred on the same point of the beam. If the system is well identified and the corresponding inverse system is designed reliably, it has shown that a very simple feed-forward active control method may be applied to suppress the residual vibrations without using an error sensor and adaptive algorithm. Both numerical simulation and experimental result show a promising possibility of applying to a practical problem.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.1064-1068
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• 2009

인지모델(Cognitive Model)에 의한 사용성 평가는 실제 실험에 의한 방법에 비해 시간, 노력, 비용을 절감할 수 있다. 여러 인지모델 중 ACT-R(Adaptive Control of Thought Rational)은 인간의 모든 인지과정을 상세하게 묘사할 수 있어 다른 모델보다 정확히 인간의 과제 수행을 정량적으로 예측할 수 있다. 그러나 ACT-R 모델을 수립하기 위해서는 인간의 지각, 주의, 기억 인출 등의 처리 과정과 행동 선택 및 수행에 필요한 과제 수행 규칙을 매우 상세하게 분석 및 기술해야 하기 때문에, GUI(Graphic User Interface) 환경에서 운용되는 메뉴 인터페이스와 같이 다양한 시각적 정보의 처리가 요구되는 과제에 대한 모델을 수립하는데는 많은 시간과 노력이 요구된다. 이에 본 연구에서는 GUI 환경에서 전문가 수준의 과제 수행을 예측할 수 있는 간략화한 ACT-R 모델 수립 방안을 제안하고, 이를 이용하여 상용 통계 분석 소프트웨어의 과제 수행도를 예측하였다. 그 결과 실제 실험을 통한 측정 결과와 간략화한 ACT-R 모델의 예측 결과가 잘 일치하였으며 본 연구에서 제시한 간략화한 ACTR 모델이 메뉴 인터페이스의 사용성 평가에 효율적으로 적용될 수 있음을 확인하였다.

• Korean Management Science Review
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• v.4
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• pp.84-98
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• 1987

After a brief discussion of the reality of OR/MS, a detailed examination is made of the impacts of academic OR/MS on its practice. These impacts include the dispersion of OR/MS in organizations, the traditional role of OR/MS, researchers, and the narrow interpretation of decision making process of current OR/MS, and the dissolution of its interdiciplinarity. The changes in OR/MS environment which should have evoked adaptive responses from it, but were not considered. The increasing inappropriateness of OR/MS methodology is discussed by focusing on the deficiencies of its concept and practice of optimization and academic role of OR/MS researchers. These deficiencies, it is argued, can be overcome by a comprehensive reconceptualization of the field, its methodology, the extended role of OR/MS researchers. Finally, the example of realizing New Paradigm, the Full Corporate Modelling with Simulation, is presented.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.5
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• pp.1840-1855
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• 2015

Troubles are often met when traditional active contours extract boundaries of medical images with inhomogeneous bias and various noises. Focusing on such a circumstance, a localized mutual information active contour model is discussed in the paper. By defining neighborhood of each point on the level set, mutual information is introduced to describe the relationship between the zero level set and image field. A driving energy term is then generated by integrating all the information. In addition, an expanding energy and internal energy are designed to regularize the driving energy. Contrary to piecewise constant model, new model has a better command of driving the contours without initialization.

• Journal of KIBIM
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• v.5 no.1
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• pp.16-24
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• 2015

The kinetic façade system is an interactive building envelope which is adaptive to environmental condition by transforming the behaviour of its components. The design process of kinetic façade system calls for a novel approach. It needs to support designers to adopt technologies from multidisciplinary fields such as physical computing and robotics. In this paper, prototyping method is introduced as a useful technique for implementing kinetic façade systems. In order to incorporate prototyping method into architectural design process, two aspects are investigated in digital design studio: (1) The interactions between digital and analogue environments (2) The role of traditional design tools. Furthermore, the role of BIM is investigated by analyzing two aspects.