• Title/Summary/Keyword: 벡터화 방식

Search Result 203, Processing Time 0.035 seconds

Empirical Analysis of K-Nearest Neighbor Recommendation Engine using Vector Similarity (K-최근접 이웃 추천 엔진에서의 벡터 유사도 사용에 대한 실험적 분석)

  • 김혜재;손기락
    • Proceedings of the Korean Information Science Society Conference
    • /
    • 2001.04b
    • /
    • pp.103-105
    • /
    • 2001
  • 인터넷 사용 인구의 폭증으로 인터넷 사이트가 경쟁적으로 유용한 각종 정보를 사용자들에게 제공하여 보다 많은 수의 회원을 확보하기 위해 노력하고 있지만 여러 사이트를 동시에 사용하고 있는 대부분의 인터넷 사용자들에게는 각 사이트에서 날아드는 정보를 매번 일일이 검색해야 하는 일이 여간 번거롭지 않을 뿐만 아니라 이런 무분별하고 획일적인 정보 서비스는 오히려 사용자들의 인터넷 사용을 불편하게 하며 더욱이 그 내용이 관심 밖의 것이 경우 네트워크의 효율적인 사용을 저해하는 정보공해에 지나지 않게 된다. 추천엔진은 기본으로 끊임없이 유입되는 다량의 정보 중에서 필요한 것을 추천해 주는 것이다. 이에 본 논문에서는 사용자들에게 필요한 정보만을 효율적으로 전달 해주기 위해서 먼저 개인화된 정보의 전달을 위해 사용자의취향을 파악하여 선택 가능성이 높은 항목을 예측할 수 있어야 한다. 그리고 사용자와 가까운 K 명의 사용자들을 효율적으로 검색하기 위해서 K-최근접 이웃 방식을 사용하고 인덱싱을 사용할 수 있는 세가지 벡터 유사도를 기존의 피어슨 상관계수(Pearson Correlation)와 비교하여 제안한다. 이를 통해 정보의 효율적인 제공방법, 즉 일반적인 검색으로 인한 정보의 제공이 아닌 일반 사용자들의 추천에 의해 정보를 제공하는 K-최근접 이웃 추천 엔진을 세가지 벡터 유사도를 이용해서 분석한다.

  • PDF

Vector Control of sensorless induction motor using Extended Kalman Filter theory (확장칼만필터 이론을 응용한 속도센서없는 유도전동기의 벡터제어)

  • 오원석;임남혁;홍찬희
    • The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.9 no.6
    • /
    • pp.41-48
    • /
    • 1995
  • In field oriented control of Induction motors, speed sensor is required, which reduces the sturdiness of drive system and together with the expenditure of hardware for faultless transmission and processing of sensor signals it causes considerable expenses. These expensive sensors can be replaced by speed sensorless concept. And for good control, the knowledge of the rotor flux component or the rotor resistance are needs. Thus, this paper is based on a Extended Kalman Filter (EKF) that estimates the state variables that are required for the control by only measuring the line voltages and currents of the machine. the rotor time constant and speed estimated by the EKF show satisfactory agreement with the real values, with the simulation approaches.

  • PDF

New Fast Block-Matching Motion Estimation using Temporal and Spatial Correlation of Motion Vectors (움직임 벡터의 시공간 상관성을 이용한 새로운 고속 블럭 정합 움직임 추정 방식)

  • 남재열;서재수;곽진석;이명호;송근원
    • Journal of Broadcast Engineering
    • /
    • v.5 no.2
    • /
    • pp.247-259
    • /
    • 2000
  • This paper introduces a new technique that reduces the search times and Improves the accuracy of motion estimation using high temporal and spatial correlation of motion vector. Instead of using the fixed first search Point of previously proposed search algorithms, the proposed method finds more accurate first search point as to compensating searching area using high temporal and spatial correlation of motion vector. Therefore, the main idea of proposed method is to find first search point to improve the performance of motion estimation and reduce the search times. The proposed method utilizes the direction of the same coordinate block of the previous frame compared with a block of the current frame to use temporal correlation and the direction of the adjacent blocks of the current frame to use spatial correlation. Based on these directions, we compute the first search point. We search the motion vector in the middle of computed first search point with two fixed search patterns. Using that idea, an efficient adaptive predicted direction search algorithm (APDSA) for block matching motion estimation is proposed. In the experimental results show that the PSNR values are improved up to the 3.6dB as depend on the Image sequences and advanced about 1.7dB on an average. The results of the comparison show that the performance of the proposed APDSA algorithm is better than those of other fast search algorithms whether the image sequence contains fast or slow motion, and is similar to the performance of the FS (Full Search) algorithm. Simulation results also show that the performance of the APDSA scheme gives better subjective picture quality than the other fast search algorithms and is closer to that of the FS algorithm.

  • PDF

Designing a Quantizer of LPC Parameters for the Narrowband Speech Coder using Block-Constrained Trellis Coded Quantization (블록 제한 트렐리스 부호화 양자화 기법을 이용한 협대역 음성 부호화기용 LPC 계수 양자화기 설계)

  • Jun, Ja-Kyoung;Park, Sang-Kuk;Kang, Sang-Won
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.32 no.3C
    • /
    • pp.234-240
    • /
    • 2007
  • In this paper, low complexity block constrained trellis coded quantization (BC-TCQ) structures are introduced, and a predictive BC TCQ encoding method is developed for quantization of line spectrum frequencies (LSF) parameters for narrowband speech coding applications. Trellis-coded quantization(TCQ) is a form of VQ that builds the VQ codebook from interleaved constituent scalar quantization codebooks. The performance is compared to the other VQ, demonstrating reduction in spectral distortion and significant reduction in encoding complexity. The predictive BC-TCQ is about 0.47107 dB superior to the IS-641 split-VQ, 26bits/frame, in spectral distortion sense. The BC-TCQ is 64.54%, 76.93%, 2.35% of the IS-641 split-VQ, respectively, in the complexity of the additions, multiplies, comparisons.

An Improvement in Intra-Slice Low Delay Video Coding for Digital TV Broadcasting (디지틀 TV 방송을 위한 저지연 intra-slice 영상 부호화 방식의 개선 방법)

  • 권순각;김재균
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.19 no.12
    • /
    • pp.2376-2385
    • /
    • 1994
  • In receiving the digital TV signal, both decoding delay and the channel hopping delay are very critical factors in applications. The intra-slice coding in the MPEG-2 SIMPLE PROFLE of No B-picture is one of the primary methods for short delay time in video decoding. It has the advantage of short decoding delay, but has the drawback of long channel hopping delay time. In this paper, we propose a method to reduce the channel delay with negligible loss in SNR performance. It is shown that dividing pictures into several regions of slices and adding some restriction in motion vector search for inter-frame coding. hence the random acess points are effectively increased. and the channel hopping delay is reduced.

  • PDF

Application and Evaluation of Vector Map Watermarking Algorithm for Robustness Enhancement (강인성 향상을 위한 벡터 맵 워터마킹 알고리즘의 적용과 평가)

  • Won, Sung Min;Park, Soo Hong
    • Spatial Information Research
    • /
    • v.21 no.3
    • /
    • pp.31-43
    • /
    • 2013
  • Although the vector map data possesses much higher values than other types of multimedia, the data copyright and the protection against illegal duplication are still far away from the attention. This paper proposes a novel watermarking technique which is both robust to diverse attacks and optimized to a vector map structure. Six approaches are proposed for the design of the watermarking algorithm: point-based approach, building a minimum perimeter triangle, watermark embedding in the length ratio, referencing to the pixel position of the watermark image, grouping, and using the one-way function. Our method preserves the characteristics of watermarking such as embedding effectiveness, fidelity, and false positive rate, while maintaining robustness to all types of attack except a noise attack. Furthermore, our method is a blind scheme in which robustness is independent of the map data. Finally, our method provides a solution to the challenging issue of degraded robustness under severe simplification attacks.

Fast Decoding Method of Distributed Video Based on Modeling of Parity Bit Requests (패리티 비트 요구량 모델링에 의한 분산 비디오의 고속 복호화 기법)

  • Kim, Man-Jae;Kim, Jin-Soo
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.16 no.11
    • /
    • pp.2465-2473
    • /
    • 2012
  • Recently, as one of low complexity video encoding methods, DVC (Distributed Video Coding) scheme has been actively studied. Most of DVC schemes exploit feedback channel to achieve better coding performances, however, this causes these schemes to have high decoding delay. In order to overcome these, this paper proposes a new fast DVC decoding method using parity-bit request model, which can be obtained by using bit-error rate, sent by encoder with motion vector, which is transmitted through feedback channel by decoder after generating side information. Through several simulations, it is shown that the proposed method improves greatly the decoding speed, compared to the conventional schemes.

Design and Implementation of Contents-based Customized movie recommendation system using meta weight learning (메타 가중치 학습을 활용한 내용 기반의 맞춤형 영화 추천시스템 설계 및 구현)

  • An, Hyeon Woo;You, Hea Woon;Kim, Dea Yeol
    • Proceedings of the Korean Society of Broadcast Engineers Conference
    • /
    • 2020.07a
    • /
    • pp.587-590
    • /
    • 2020
  • 최근, 디지털 콘텐츠 산업이 폭발적으로 성장됨에 따라 고객 유치를 위한 개인화 추천 기술들이 많은 주목을 받고 있다. 개인화 추천 방식들을 큰 갈래로 나누어 본다면 협업 필터링 기술과 내용 기반 기술로 나눌 수 있다. 협업 필터링의 경우 개인화 추천에는 적합하지만 사용자 평가 데이터의 양이 방대해야 하며 초기에 평가자가 없는 콘텐츠에 대해 추천할 수 없는 초기 평가자 문제가 존재한다. 따라서 매일 방대한 양의 콘텐츠가 편입되는 분야에서 사용하기에 큰 결점이 될 수 있다. 본 논문에서는 영화들의 정보가 담긴 데이터 셋과 사용자 평가 데이터, 그리고 사용자의 선호 기준을 의미하는 메타 가중치를 활용한 내용 기반의 맞춤형 영화 추천 시스템을 제안한다. 논문에서는 먼저, 영화를 고를 때 일반적으로 중요시 보는 속성들을 활용하여 영화의 특징 벡터를 구성하고, 이를 사용자 평가와 결합하여 개인의 선호에 대한 특징 벡터를 구성하는 방법을 제안하며, 구성된 데이터와 코사인 유사도, 메타 가중치를 활용하여 사용자 선호와 유사한 영화들을 도출하는 방법을 제안한다. 또한, 평가데이터를 활용하여 구현된 추천시스템의 검증 프로세스를 구성하고, 검증 프로세스를 활용한 손실 함수를 설계하여 적합한 메타 가중치를 학습하는 방법을 제시한다. 본 논문에서 제안하는 시스템은 다수의 속성을 조합하여 활용하므로 추천 결과가 과도하게 특수화 되지 않을 수 있으며, 메타 가중치라는 요소를 통해 더욱 개인화 된 추천을 제공할 수 있다.

  • PDF

Performance of Magnitude Sum Correlation and Vector Sum Correlation Methods for Robust Frame Synchronization Under Low Signal-to-Noise Ratios (낮은 신호 대 잡음 비에서 강건한 프레임 동기를 위한 크기 합 상관 및 벡터 합 상관 방식의 성능 평가)

  • Lee, Dong-Uk;Kim, Sang-Tae;Sung, Won-Jin
    • Journal of the Institute of Electronics Engineers of Korea TC
    • /
    • v.45 no.7
    • /
    • pp.32-37
    • /
    • 2008
  • Satellite communication systems including the DVB-S2 (Digital Video Broadcasting - Satellite Version 2) system require operations under low signal-to-noise ratio (SNR) and large frequency offset values, and the initial frame synchronization process necessitates a robust correlation method. While a variety of conventional correlation structures exist for the initial synchronization, each method has different characteristics and performance in different channel environments. In this paper, we propose new correlation methods which exhibit enhanced performance in low SNR and large frequency offsets, and analyze their performance. The proposed methods use the magnitude sum and vector sum of extended differential correlation values, to maximize the correlation between the received signal and the synchronization sequence by using the spanned differential correlation result. The magnitude sum correlation method has better performance compared to conventional methods including the approximated ML (Maximum likelihood) method for SNR values below 4 dB with or without frequency offsets. The vector sum correlation method has improved performance over the magnitude sum method for channels with relatively small frequency offsets.