• Title/Summary/Keyword: consensus algorithm

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Fast Outlier Removal for Image Registration based on Modified K-means Clustering

  • Soh, Young-Sung;Qadir, Mudasar;Kim, In-Taek
    • Journal of the Institute of Convergence Signal Processing
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    • v.16 no.1
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    • pp.9-14
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    • 2015
  • Outlier detection and removal is a crucial step needed for various image processing applications such as image registration. Random Sample Consensus (RANSAC) is known to be the best algorithm so far for the outlier detection and removal. However RANSAC requires a cosiderable computation time. To drastically reduce the computation time while preserving the comparable quality, a outlier detection and removal method based on modified K-means is proposed. The original K-means was conducted first for matching point pairs and then cluster merging and member exclusion step are performed in the modification step. We applied the methods to various images with highly repetitive patterns under several geometric distortions and obtained successful results. We compared the proposed method with RANSAC and showed that the proposed method runs 3~10 times faster than RANSAC.

A Study on the PSP-Platform for the Atomicity of Distributed Ledger

  • Lee, Eun-Hee;Yoon, Yong-Ik
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.5
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    • pp.73-80
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    • 2019
  • In Korea, a budget of tens of trillion won is put into the national R & D project every year. Thanks to these efforts, Korea's ICT industry is gaining global attention. However, there are still a lot of problems that are lacking in terms of the cycle of managing national ICT R&D projects. In particular, the issue of sharing is very insufficient throughout the cycle of the national ICT R&D. In this paper, In this paper, We propose a platfom that can be shared throughout the cycle of managing blockchain-based national ICT R&D projects. This platform we call the Perfect Sharing Project Platform (PSPP). We describe that PSPP can achieve excellent research results through information sharing of project process[1-2]. To support the perfect sharing, this platform uses a new notion of consensus algorithm, called POA (Proof of Atomicity). This platform is suitable for sharing information.

The Determination of the Duration of Electroconvulsive Therapy-Induced Seizure Using Local Standard Deviation of the Electroencephalogram Signal and the Changes of the RR Interval of Electrocardiogram

  • Kim, Eun Young;Yoo, Cheol Seung;Jung, Dong Chung;Yi, Sang Hoon;Chung, In-Won;Kim, Yong Sik;Ahn, Yong Min
    • Korean Journal of Biological Psychiatry
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    • v.27 no.1
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    • pp.1-8
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    • 2020
  • Objectives In electroconvulsive therapy (ECT) research and practice, the precise determination of seizure duration is important in the evaluation of clinical relevance of the ECT-induced seizure. In this study, we have developed computerized algorithms to assess the duration of ECT-induced seizure. Methods Subjects included 5 males and 6 females, with the mean age of 33.1 years. Total 55 ECT sessions were included in the analysis. We analyzed the standard deviation of a finite block of electroencephalography (EEG) data and the change in the local slope of RR intervals in electrocardiography (ECG) signals during ECT-induced seizure. And then, we compared the calculated seizure durations from EEG recording (EEG algorithm) and ECG recording (ECG algorithm) with values determined by consensus of clinicians based on the recorded EEG (EEG consensus), as a gold standard criterion, in order to testify the computational validity of our algorithms. Results The mean seizure durations calculated by each method were not significantly different in sessions with abrupt flattened postictal suppression and in sessions with non-abrupt flattened postictal suppression. The intraclass correlation coefficients (95% confidence interval) of the three methods (EEG algorithm, ECG algorithm, EEG consensus) were significant in the total sessions [0.79 (0.70-0.86)], the abrupt flattened postictal suppression sessions [0.84 (0.74-0.91)], and the non-abrupt flattened postictal suppression sessions [0.67 (0.45-0.84)]. Correlations between three methods were also statistically significant, regardless of abruptness of transition. Conclusions Our proposed algorithms could reliably measure the duration of ECT-induced seizure, even in sessions with non-abrupt transitions to flat postictal suppression, in which it is typically difficult to determine the seizure duration.

Fast Logic Minimization Algorithm for Programmable-Logic-Array Design (PLA 설계용 고속 논리최소화 알고리즘)

  • 최상호;임인칠
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.22 no.2
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    • pp.25-30
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    • 1985
  • This paper proposes an algorithm to simplify Boolean functions into near minimal sum-of-products for Programmable Logic Arrays. In contrast to the conventional procedures, where the execution time depends on the number of variables, the execution time by this procedure depends on the degree of consensus of base minterms. Thus as the number of variables is increased, the difference of CPU time becomes larger using this new Procedure than using other procedures and consequently the executable range of input function increasing. The algorithm has been implemented on CYEER 170-740 and it's results were compared with those using Arvalo's algorithm.

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Problems and solutions of FPC algorithm in Software-Defined Networks (SDN에서 FPC 알고리즘의 문제점과 해결방안)

  • Yoo, Seung-Eon;Kim, Dong-Hyun;Kim, Kyung-Tae;Youn, Hee-Young
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2018.01a
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    • pp.11-12
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    • 2018
  • FPC 알고리즘(Fast Paox-based controller algorithm)은 기존에 Paxos 프로토콜을 단순화하고 Paxos를 개발하고 구현하는 복잡성을 완화할 수 있는 다중 SDN 컨트롤러 간에 적용되는 합의를 처리할 수 있는 알고리즘이다. 하지만, 허가를 결정하는 투표 과정에서 불필요한 절차가 존재하여 연산 속도가 감소하고 계산 비용이 많이 든다는 단점이 있다. 본 논문에서는 이러한 단점을 극복하는 해결책을 제시하여 알고리즘의 성능이 향상되는 것을 증명하였다.

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A panorama image generation method using FAST algorithm (FAST를 이용한 파노라마 영상 생성 방법)

  • Kim, Jong-ho;Ko, Jin-woong;Yoo, Jisang
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.3
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    • pp.630-638
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    • 2016
  • In this paper, a feature based panorama image generation algorithm using FAST(Features from Accelerated Segment Test) method that is faster than SIFT(Scale Invariant Feature Transform) and SURF(Speeded Up Robust Features) is proposed. Cylindrical projection is performed to generate natural panorama images with numerous images as input. The occurred error can be minimized by applying RANSAC(Random Sample Consensus) for the matching process. When we synthesize numerous images acquired from different camera angles, we use blending techniques to compensate the distortions by the heterogeneity of border line. In that way, we could get more natural synthesized panorama image. The proposed algorithm can generate natural panorama images regardless the order of input images and tilted images. In addition, the image matching can be faster than the conventional method. As a result of the experiments, distortion was corrected and natural panorama image was generated.

Fast Stitching Algorithm by using Feature Tracking (특징점 추적을 통한 다수 영상의 고속 스티칭 기법)

  • Park, Siyoung;Kim, Jongho;Yoo, Jisang
    • Journal of Broadcast Engineering
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    • v.20 no.5
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    • pp.728-737
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    • 2015
  • Stitching algorithm obtain a descriptor of the feature points extracted from multiple images, and create a single image through the matching process between the each of the feature points. In this paper, a feature extraction and matching techniques for the creation of a high-speed panorama using video input is proposed. Features from Accelerated Segment Test(FAST) is used for the feature extraction at high speed. A new feature point matching process, different from the conventional method is proposed. In the matching process, by tracking region containing the feature point through the Mean shift vector required for matching is obtained. Obtained vector is used to match the extracted feature points. In order to remove the outlier, the RANdom Sample Consensus(RANSAC) method is used. By obtaining a homography transformation matrix of the two input images, a single panoramic image is generated. Through experimental results, we show that the proposed algorithm improve of speed panoramic image generation compared to than the existing method.

Consensus-based Autonomous Search Algorithm Applied for Swarm of UAVs (군집 무인기 활용을 위한 합의 기반 자율 탐색 알고리즘)

  • Park, Kuk-Kwon;Kwon, Ho-Jun;Choi, Eunju;Ryoo, Chang-Kyung
    • Journal of Advanced Navigation Technology
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    • v.21 no.5
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    • pp.443-449
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    • 2017
  • Swarm of low-cost UAVs for search mission has benefit in the sense of rapid search compared to use of single high-end UAV. As the number of UAVs forming swarm increases, not only the time for the mission planning increases, but also the system to operate UAVs has excessive burden. This paper addresses a decentralized area search algorithm adequate for multiple UAVs which takes advantages of flexibility, robustness, and simplicity. To down the cost, it is assumed that each UAV has limited ability: close-communication, basic calculation, and limited memory. In close-communication, heath conditions and search information are shared. And collision avoidance and consensus of next search direction are then done. To increase weight on un-searched area and to provide overlapped search, the score function is introduced. Performance and operational characteristics of the proposed search algorithm and mission planning logic are verified via numerical simulations.

Stack Bin Packing Algorithm for Containers Pre-Marshalling Problem

  • Lee, Sang-Un
    • Journal of the Korea Society of Computer and Information
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    • v.20 no.10
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    • pp.61-68
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    • 2015
  • This paper deals with the pre-marshalling problem that the containers of container yard at container terminal are relocated in consensus sequence of loading schedule of container vessel. This problem is essential to improvement of competitive power of terminal. This problem has to relocate the all of containers in a bay with minimum number of movement. There are various algorithms such as metaheuristic as genetic algorithm and heuristic algorithm in order to find the solution of this problem. Nevertheless, there is no unique general algorithm that is suitable for various many data. And the main drawback of metaheuristic methods are not the solution finding rule but can be find the approximated solution with many random trials and by coincidence. This paper can be obtain the solution with O(m) time complexity that this problem deals with bin packing problem for m stack bins with descending order of take out ranking. For various experimental data, the proposed algorithm can be obtain the optimal solutions for all of data. And to conclude, this algorithm can be show that most simple and general algorithm with simple optimal solution finding rule.

An Algorithm for a pose estimation of a robot using Scale-Invariant feature Transform

  • Lee, Jae-Kwang;Huh, Uk-Youl;Kim, Hak-Il
    • Proceedings of the KIEE Conference
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    • 2004.11c
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    • pp.517-519
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    • 2004
  • This paper describes an approach to estimate a robot pose with an image. The algorithm of pose estimation with an image can be broken down into three stages : extracting scale-invariant features, matching these features and calculating affine invariant. In the first step, the robot mounted mono camera captures environment image. Then feature extraction is executed in a captured image. These extracted features are recorded in a database. In the matching stage, a Random Sample Consensus(RANSAC) method is employed to match these features. After matching these features, the robot pose is estimated with positions of features by calculating affine invariant. This algorithm is implemented and demonstrated by Matlab program.

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