• Title/Summary/Keyword: multi-scale method

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Multi-stage Transformer for Video Anomaly Detection

  • Viet-Tuan Le;Khuong G. T. Diep;Tae-Seok Kim;Yong-Guk Kim
    • Proceedings of the Korea Information Processing Society Conference
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    • 2023.11a
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    • pp.648-651
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    • 2023
  • Video anomaly detection aims to detect abnormal events. Motivated by the power of transformers recently shown in vision tasks, we propose a novel transformer-based network for video anomaly detection. To capture long-range information in video, we employ a multi-scale transformer as an encoder. A convolutional decoder is utilized to predict the future frame from the extracted multi-scale feature maps. The proposed method is evaluated on three benchmark datasets: USCD Ped2, CUHK Avenue, and ShanghaiTech. The results show that the proposed method achieves better performance compared to recent methods.

GAN-based Image-to-image Translation using Multi-scale Images (다중 스케일 영상을 이용한 GAN 기반 영상 간 변환 기법)

  • Chung, Soyoung;Chung, Min Gyo
    • The Journal of the Convergence on Culture Technology
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    • v.6 no.4
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    • pp.767-776
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    • 2020
  • GcGAN is a deep learning model to translate styles between images under geometric consistency constraint. However, GcGAN has a disadvantage that it does not properly maintain detailed content of an image, since it preserves the content of the image through limited geometric transformation such as rotation or flip. Therefore, in this study, we propose a new image-to-image translation method, MSGcGAN(Multi-Scale GcGAN), which improves this disadvantage. MSGcGAN, an extended model of GcGAN, performs style translation between images in a direction to reduce semantic distortion of images and maintain detailed content by learning multi-scale images simultaneously and extracting scale-invariant features. The experimental results showed that MSGcGAN was better than GcGAN in both quantitative and qualitative aspects, and it translated the style more naturally while maintaining the overall content of the image.

Probabilistic Load Flow for Power Systems with Wind Power Considering the Multi-time Scale Dispatching Strategy

  • Qin, Chao;Yu, Yixin;Zeng, Yuan
    • Journal of Electrical Engineering and Technology
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    • v.13 no.4
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    • pp.1494-1503
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    • 2018
  • This paper proposes a novel probabilistic load flow model for power systems integrated with large-scale wind power, which considers the multi-time scale dispatching features. The ramp limitations of the units and the steady-state security constraints of the network have been comprehensively considered for the entire duration of the study period; thus, the coupling of the system operation states at different time sections has been taken into account. For each time section, the automatic generation control (AGC) strategy is considered, and all variations associated with the wind power and loads are compensated by all AGC units. Cumulants and the Gram-Charlier expansion are used to solve the proposed model. The effectiveness of the proposed method is validated using the modified IEEE RTS 24-bus system and the modified IEEE 118-bus system.

Multi-Central System for Large Scale PV Power Generation (대용량 태양광 발전용 멀티센트럴 시스템)

  • Park, Jong-Hyoung;Ko, Kwang-Soo;Kim, Heung-Geun;Nho, Eui-Cheol;Chun, Tae-Won
    • 한국태양에너지학회:학술대회논문집
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    • 2012.03a
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    • pp.427-432
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    • 2012
  • This paper proposes efficient operation method of PV system consisted of multi-central which is suitable for large scale system. The multi-central system used switch at a DC-link and applied proposed algorithm can improve the efficiency and the reliability on the existing system. This algorithm, with advantage of Multi-Central system can minimize the effect of different characteristic of each PV array due to a shadow or damaged PV cell. Each system is analysed and maximum power point tracking control, DC-link voltage control and output current control is used commonly. The validity is verified after comparing of the existing system and proposed system by simulation.

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A Study on the Frequency Transfer Function of a Full-Scale Ship Considering the Multi-Directional Waves (다방향파를 고려한 실선 주파수 전달함수 도출기법 연구)

  • J.C. Kim;I.K. Park;H.J. Jo;J.A. Kim
    • Journal of the Society of Naval Architects of Korea
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    • v.31 no.4
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    • pp.51-57
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    • 1994
  • In this study, the method for calculation of the frequency transfer function of motions based on the multi-directional waves in the analysis of a full-scale seakeeping trials is presented. For calculation of the frequency transfer function in the directional waves, Takezawa's inverse estimation method was introduced and the frequency ranges were divided into three parts in order to consider following seas. To confirm the validity of this method, the numerical simulation was executed. Those results show that analysis method of the multi-directional waves is more reliable than that of one directional waves, and confirm the possibility of applying this method to the full-scathe seakeeping trials.

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An image enhancement-based License plate detection method for Naturally Degraded Images

  • Khan, Khurram;Choi, Myung Ryul
    • Journal of IKEEE
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    • v.22 no.4
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    • pp.1188-1194
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    • 2018
  • This paper proposes an image enhancement-based license plate detection algorithm to improve the overall performance of system. Non-uniform illumination conditions have huge impact on overall plate detection system accuracy. In this paper, we propose an algorithm for color image enhancement-based license plate detection for improving accuracy of images degraded by excessively strong and low sunlight. Firstly, the image is enhanced by Multi-Scale Retinex algorithm. Secondly, a plate detection method is employed to take advantage of geometric properties of connected components, which can significantly reduce the undesired plate regions. Finally, intersection over union method is applied for detecting the accurate location of number plate. Experimental results show that the proposed method significantly improves the accuracy of plate detection system.

Eye Localization based on Multi-Scale Gabor Feature Vector Model (다중 스케일 가버 특징 벡터 모델 기반 눈좌표 검출)

  • Kim, Sang-Hoon;Jung, Sou-Hwan;Oh, Du-Sik;Kim, Jae-Min;Cho, Seong-Won;Chung, Sun-Tae
    • The Journal of the Korea Contents Association
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    • v.7 no.1
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    • pp.48-57
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    • 2007
  • Eye localization is necessary for face recognition and related application areas. Most of eye localization algorithms reported thus far still need to be improved about precision and computational time for successful applications. In this paper, we propose an improved eye localization method based on multi-scale Gator feature vector models. The proposed method first tries to locate eyes in the downscaled face image by utilizing Gabor Jet similarity between Gabor feature vector at an initial eye coordinates and the eye model bunch of the corresponding scale. The proposed method finally locates eyes in the original input face image after it processes in the same way recursively in each scaled face image by using the eye coordinates localized in the downscaled image as initial eye coordinates. Experiments verify that our proposed method improves the precision rate without causing much computational overhead compared with other eye localization methods reported in the previous researches.

FCM for the Multi-Scale Problems (고속 최소자승 점별계산법을 이용한 멀티 스케일 문제의 해석)

  • 김도완;김용식
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2002.10a
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    • pp.599-603
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    • 2002
  • We propose a new meshfree method to be called the fast moving least square reproducing kernel collocation method(FCM). This methodology is composed of the fast moving least square reproducing kernel(FMLSRK) approximation and the point collocation scheme. Using point collocation makes the meshfree method really come true. In this paper, FCM Is shown to be a good method at least to calculate the numerical solutions governed by second order elliptic partial differential equations with geometric singularity or geometric multi-scales. To treat such problems, we use the concept of variable dilation parameter.

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Adaptive fluid-structure interaction simulation of large-scale complex liquid containment with two-phase flow

  • Park, Sung-Woo;Cho, Jin-Rae
    • Structural Engineering and Mechanics
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    • v.41 no.4
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    • pp.559-573
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    • 2012
  • An adaptive modeling and simulation technique is introduced for the effective and reliable fluid-structure interaction analysis using MSC/Dytran for large-scale complex pressurized liquid containment. The proposed method is composed of a series of the global rigid sloshing analysis and the locally detailed fluid-structure analysis. The critical time at which the system exhibits the severe liquid sloshing response is sought through the former analysis, while the fluid-structure interaction in the local region of interest at the critical time is analyzed by the latter analysis. Differing from the global coarse model, the local fine model considers not only the complex geometry and flexibility of structure but the effect of internal pressure. The locally detailed FSI problem is solved in terms of multi-material volume fractions and the flow and pressure fields obtained by the global analysis at the critical time are specified as the initial conditions. An in-house program for mapping the global analysis results onto the fine-scale local FSI model is developed. The validity and effectiveness of the proposed method are verified through an illustrative numerical experiment.

A Multi-Layer Perceptron for Color Index based Vegetation Segmentation (색상지수 기반의 식물분할을 위한 다층퍼셉트론 신경망)

  • Lee, Moon-Kyu
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.43 no.1
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    • pp.16-25
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    • 2020
  • Vegetation segmentation in a field color image is a process of distinguishing vegetation objects of interests like crops and weeds from a background of soil and/or other residues. The performance of the process is crucial in automatic precision agriculture which includes weed control and crop status monitoring. To facilitate the segmentation, color indices have predominantly been used to transform the color image into its gray-scale image. A thresholding technique like the Otsu method is then applied to distinguish vegetation parts from the background. An obvious demerit of the thresholding based segmentation will be that classification of each pixel into vegetation or background is carried out solely by using the color feature of the pixel itself without taking into account color features of its neighboring pixels. This paper presents a new pixel-based segmentation method which employs a multi-layer perceptron neural network to classify the gray-scale image into vegetation and nonvegetation pixels. The input data of the neural network for each pixel are 2-dimensional gray-level values surrounding the pixel. To generate a gray-scale image from a raw RGB color image, a well-known color index called Excess Green minus Excess Red Index was used. Experimental results using 80 field images of 4 vegetation species demonstrate the superiority of the neural network to existing threshold-based segmentation methods in terms of accuracy, precision, recall, and harmonic mean.