• Proceedings of the Korean Society of Computer Information Conference
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• 2017.01a
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• pp.73-74
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• 2017

SVM(Support Vector Machine) 알고리즘은 대표적인 기계 학습 분류 알고리즘으로 감정 분석, 제스처 인식 등 다양한 분야의 문제를 해결하기 위해 사용되고 있다. SVM 알고리즘은 분리경계면(Hyper-Plane) 또는 분리경계면 집합 중 지지벡터(Support Vector)라 불리는 특정한 점들로 이루어진 두 그룹 간의 거리 차이(Margin)를 최대로 하는 분리경계면을 이용하여 데이터를 분류하는 알고리즘이다. 높은 정확도를 제공하지만 처리 속도가 느리며 학습을 위해 대량의 데이터 및 메모리가 필요하기 때문에 자원이 제한적인 IoT 환경에서 사용이 어렵다. 본 논문에서는 자원이 제한된 IoT 노드를 기반으로 효율적으로 데이터를 학습하기 위해 K-means 알고리즘을 이용하여 SVM 알고리즘의 저전력화 방안을 연구한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.6B
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• pp.784-793
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• 2001

본 논문에서는 이산 여현변환에 기반으로 한 고압축의 복원된 영상으로 발생하는 블록화 현상을 제거하기 위한 개선된 후처리 기법을 제안한다. 먼저 압축으로부터 복원된 영상에 대하여, 변환 블록단위로 계산된 블록 경계 불연속값을 이용하여 블록화현상 블록과 에지블록을 구별한다. 블록화현상 블록은 다시 블록 경계면의 격차 정도에 따라 적응적으로 블록경계에서 필터링되는 화소 범위를 다르게 하여 필터링하며, 에지 블록은 다시 화소단위로 에지화소 여부를 조사하여, 에지가 아닌 화소만 필터링을 취하여 좀 더 세밀하게 블록화 현상을 제거하는 새로운 방법을 제안한다. 실험 결과를 통하여 제안한 방법이 기존 방법에 비해 시각적으로 향상된 영상을 얻을 수 있음을 입증하였다.

• Journal of the Korean Institute of Intelligent Systems
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• v.25 no.1
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• pp.78-84
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• 2015

Depth estimation is often required for robot vision, 3D modeling, and motion control. Previous method is based on the focus measures which are calculated for a series of image by a single camera at different distance between and object. This method, however, has disadvantage of taking a long time for calculating the focus measure since the mask operation is performed for every pixel in the image. In this paper, we estimates the depth by using the focus measure of the boundary pixels located between the objects in order to minimize the depth estimate time. To detect the boundary of an object consisting of a straight line and a circle, we use the Hough transform and estimate the depth by using the focus measure. We performed various experiments for PCB images and obtained more effective depth estimation results than previous ones.

• Journal of KIISE:Software and Applications
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• v.27 no.5
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• pp.529-542
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• 2000

Recent years, the use of multimedia information is rapidly increasing, and the video media is the most rising one than any others, and this field Integrates all the media into a single data stream. Though the availability of digital video is raised largely, it is very difficult for users to make the effective video access, due to its length and unstructured video format. Thus, the minimal interaction of users and the explicit definition of video structure is a key requirement in the lately developing image and video management systems. This paper defines the terms and hierarchical video structure, and presents the system, which construct the clustering-based video hierarchy, which facilitate users by browsing the summary and do a random access to the video content. Instead of using a single feature and domain-specific thresholds, we use multiple features that have complementary relationship for each other and clustering-based methods that use normalization so as to interact with users minimally. The stage of shot boundary detection extracts multiple features, performs the adaptive filtering process for each features to enhance the performance by eliminating the false factors, and does k-means clustering with two classes. The shot list of a result after the proposed procedure is represented as the video hierarchy by the intelligent unsupervised clustering technique. We experimented the static and the dynamic movie videos that represent characteristics of various video types. In the result of shot boundary detection, we had almost more than 95% good performance, and had also rood result in the video hierarchy.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.512-515
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• 2011

터널 해석은 주로 지표침하와 터널 라이닝 내 단면력 산정에 초점이 맞춰지며 이는 시공단계를 고려한 3차원 수치해석 모델을 이용해 결정할 수 있다. 수치해석 시 shield는 응력 제어, shell element로 모델링하는 방법 등으로 모사될 수 있다. 한편 변위 제어를 통한 쉴드 모사는 shield를 적절한 경계조건으로 처리함으로서, 다른 shield 모사 방법에 비해 모델링 작업을 간소화하고 해석의 효율성을 높일 수 있다. 본 연구에서는 변위 제어에 의한 shield 모사를 위한 적정 경계조건을 제안한다. 이를 위해 시공단계가 고려된 유한요소해석을 사용하여, 쉴드 및 굴착면에서의 경계조건 변화와 이에 따른 지표침하 관측 수행하였다. 제안된 shield 변위 제어로부터 얻어진 해석결과를 이론적인 해와 비교함으로서, 제시된 shield 모델링 방법의 적정성과 지반 거동 변화를 평가하고자 한다. 해석 결과는 지반 모델의 지표침하를 기준으로 관찰되었으며, 변위제어에 의한 결과와 요소에 의한 모델링 결과가 유사하게 얻어짐을 보여준다. 또한 변위제어의 쉴드 모사에서 회전 구속보다 변위 구속 조건에 지배적으로 영향을 받음을 확인하였다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.1
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• pp.39-47
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• 2016

Repair methods of aging concrete pavement are generally used composite structure pavements, such a composite structure is subjected to a large impact on the mechanical behavior and ensure long-term commonality integrated under vehicle loads, environmental loads of the public in accordance with the bond strength between old and new concrete. A common of bonded concrete overlays that are currently available is Interface arrangements using a variety of equipment to ensure the excellent bond strength between old and new concrete than standard concrete, mixed with a material such as a polymer in order to improve the adhesion with the material itself. However, these method of constructions are being applied, depending on the developer site presents no special specifications apply when a specific application criteria objectively, this is due to the situation of each individual method, which is based on the difficulty in quality control of the site manager. In this study by performing a field test for polymer content via the variables that contribute most significantly to ensure bond strength and the field element core of the interface processing method and materials to ensure bond strength between the old and the new concrete, it was to derive the construction site construction method that can improve the performance of the bond strength through a review of the construction around the correlations and the bond strength according to the effective performance analysis of the conventional surface treatment process and variation of polymer volume fraction.

• The KIPS Transactions:PartB
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• v.11B no.7 s.96
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• pp.841-848
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• 2004

Evolutionary a1gorithms are well-suited for multi-objective optimization problems involving several, often conflicting objectives. Pareto-based evolutionary algorithms, in particular, have shown better performance than other multi-objective evolutionary algorithms in comparison. However, generalized evolutionary multi-objective optimization algorithms have a weak point, in which the distribution of solutions are not uni-formly distributed onto Pareto optimal front. In this paper, we propose an evolutionary a1gorithm for multi-objective optimization which uses seed individuals in order to overcome weakness of algorithms Published. Seed individual means a solution which is not located in the crowded region on Pareto front. And the idea of our algorithm uses seed individuals for reproducing individuals for next generation. Thus, proposed a1go-rithm takes advantage of local searching effect because new individuals are produced near the seed individual with high probability, and is able to produce comparatively uniform distributed pareto optimal solutions. Simulation results on five testbed problems show that the proposed algo-rithm could produce uniform distributed solutions onto pareto optimal front, and is able to show better convergence compared to NSGA-II on all testbed problems except multi-modal problem.

• The Transactions of the Korea Information Processing Society
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• v.5 no.3
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• pp.862-872
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• 1998

In this paper, we developed a delay test architecture and test procedure for clocked sequential circuit. In addition, we analyze the problems of conventional and previous method on delay test for clocked sequential circuit in IEEE 1149.1. This paper discusses several problems of Delay test on IEEE 1149.1 for clocked sequential circuit. Previous method has some problems of improper capture timing, of same pattern insertion, of increase of test time. We suggest a method called ARCH-S, is based on a clock counting technique to generate continuous clocks for clocked input of CUT. A 4-bit counter is selected for the circuit under test. The simulation results ascertain the aecurate operation and effectiveness of the proposed architecture.

• Journal of computational fluids engineering
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• v.4 no.3
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• pp.28-34
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• 1999

The objective of this study is to present a numerical treatment of the pressure gradient when control volumes are sharing the interface between a homogeneous fluid and a porous medium. Two possible approaches, e.g. linear interpolation and extrapolation, are considered, and they are applied to the case of a steady and two-dimensional curved channel flow which is partially filled with a porous medium. It was found that the linear extrapolation produces a continuous velocity-field at the interface and thus is recommended. On the contrary, the linear interpolation entails a discontinuous velocity field at the interface, thereby warning its use in connection with the Brinkman-Forchheimer-extended Darcy flow model.

• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.2
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• pp.111-119
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• 2016

Gas-Liquid multiphase flow simulation has been carried out using the Lattice boltzmann method. For the interface treatment, pseudo-potential model (Shan-Chen) was used with the Carnahan-Starling equation of state. Exact Difference Method also applied for the treatment of the force term. Through the developed code, we simulated coexsitence structure of high and low density, phase separation, surface tension effect, characteristics of moving interface, homogeneous and heterogeneous cavitation and bubble collaps.