• Title/Summary/Keyword: metric space

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Reception Performance Evaluation of LDPC-Encoded SOQPSK-TG (LDPC 부호화한 SOQPSK-TG의 수신 성능 평가)

  • Gu, Young Mo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.49 no.10
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    • pp.879-882
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    • 2021
  • The telemetry standard adopts SOQPSK-TG with excellent power and bandwidth efficiency as a modulation technique, and LDPC code with excellent performance as an error correction code. The SOQPSK-TG transmitter consists of a precoder and a CPM modulator. Rather than implementing each receiver separately, the reception performance is improved by combining the trellis and implementing it as a Viterbi decoder. In this paper, the reception performance of LDPC-encoded SOQPSK-TG was evaluated by replacing the Viterbi decoder with a max-log-map decoder capable of soft metric output. As a result of computer simulation in AWGN channel, there is an Eb/No performance gain of about more than 0.7~0.8dB compared to the conventional method.

Incoming and Outgoing Human Matching Using Similarity Metrics for Occupancy Sensor (점유센서를 위한 유사성 메트릭을 이용한 입출입 사람 매칭)

  • Woo, Youngje;Jeong, Jaejoon;Choi, Changyeol;Kim, Manbae
    • Journal of Broadcast Engineering
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    • v.24 no.2
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    • pp.353-356
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    • 2019
  • The main functionality of occupancy sensors is to determine the existence of humans in the space. If the space is occupied, a light is on and for vacancy, the light automatically turns off. In this letter, the functionality is realized by the utilization of color information. The color information of incoming people is saved. For outgoing people, their color distribution is compared with the saved information, thus providing the recognition of the outgoing people. For the comparison, four similarity metrics are examined to validate the proposed method.

Color Transfer Method Based on Separation of Saturation (채색 분리 기반의 색 변환 기법)

  • Kwak, Jung-Min;Kim, Jae-Hyup;Moon, Young-Shik
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.45 no.3
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    • pp.149-159
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    • 2008
  • We present new methods which transfer the color style of a source image into an arbitrary given reference image. Misidentification problem of color cause wrong indexing in low saturation. Therefore, the proposed method do indexing after Image separating chromatic and achromatic color from saturation. The proposed method is composed of the following four steps : In the first step, Image separate chromatic and achromatic color from saturation using threshold. In the second step, image of separation do indexing using cylindrical metric. In the third step, the number and positional dispersion of pixel decide the order of priority for each index color. And average and standard deviation of each index color be calculated. In the final step, color be transferred in Lab color space, and post processing to removal noise and pseudo-contour. Experimental results show that the proposed method is effective on indexing and color transfer.

Light Pollution of Outdoor Lighting in Coastal Area - Focused on Busan City - (해안가 야간경관조명의 빛공해 평가 - 부산시를 중심으로 -)

  • Kong, Hyo-Joo;Kim, Jeong-Tai
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.6
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    • pp.18-26
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    • 2010
  • Outdoor lighting has become a necessary essential part of society for safety and comfortable space. However, inappropriate outdoor lighting leads to energy waste and poor landscape. Outdoor lighting is a very important social element, which enables us to conduct various activities at night in a safe, efficient and comfort way. River Thames in UK, Venice in Italy and Sydney in Australia is a good example of the coastal area. This paper aims to evaluate the light pollution of outdoor lighting in coastal area in Busan city. The Radiant Imaging ProMetric-1400 was used to measure the luminance of Gwangalli Beach, Marine City and Haeundae Beach. Compare to the CIE recommendation level the luminance of the all outdoor lighting were about 2~20 times higher. Outdoor lighting of the building facade luminance level and color should be particularly limited.

Augmented Reality Using Projective Information (비유클리드공간 정보를 사용하는 증강현실)

  • 서용덕;홍기상
    • Journal of Broadcast Engineering
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    • v.4 no.2
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    • pp.87-102
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    • 1999
  • We propose an algorithm for augmenting a real video sequence with views of graphics ojbects without metric calibration of the video camera by representing the motion of the video camera in projective space. We define a virtual camera, through which views of graphics objects are generated. attached to the real camera by specifying image locations of the world coordinate system of the virtual world. The virtual camera is decomposed into calibration and motion components in order to make full use of graphics tools. The projective motion of the real camera recovered from image matches has a function of transferring the virtual camera and makes the virtual camera move according to the motion of the real camera. The virtual camera also follows the change of the internal parameters of the real camera. This paper shows theoretical and experimental results of our application of non-metric vision to augmented reality.

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Hard Example Generation by Novel View Synthesis for 3-D Pose Estimation (3차원 자세 추정 기법의 성능 향상을 위한 임의 시점 합성 기반의 고난도 예제 생성)

  • Minji Kim;Sungchan Kim
    • IEMEK Journal of Embedded Systems and Applications
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    • v.19 no.1
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    • pp.9-17
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    • 2024
  • It is widely recognized that for 3D human pose estimation (HPE), dataset acquisition is expensive and the effectiveness of augmentation techniques of conventional visual recognition tasks is limited. We address these difficulties by presenting a simple but effective method that augments input images in terms of viewpoints when training a 3D human pose estimation (HPE) model. Our intuition is that meaningful variants of the input images for HPE could be obtained by viewing a human instance in the images from an arbitrary viewpoint different from that in the original images. The core idea is to synthesize new images that have self-occlusion and thus are difficult to predict at different viewpoints even with the same pose of the original example. We incorporate this idea into the training procedure of the 3D HPE model as an augmentation stage of the input samples. We show that a strategy for augmenting the synthesized example should be carefully designed in terms of the frequency of performing the augmentation and the selection of viewpoints for synthesizing the samples. To this end, we propose a new metric to measure the prediction difficulty of input images for 3D HPE in terms of the distance between corresponding keypoints on both sides of a human body. Extensive exploration of the space of augmentation probability choices and example selection according to the proposed distance metric leads to a performance gain of up to 6.2% on Human3.6M, the well-known pose estimation dataset.

AFFINE YANG-MILLS CONNECTIONS ON NORMAL HOMOGENEOUS SPACES

  • Park, Joon-Sik
    • Honam Mathematical Journal
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    • v.33 no.4
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    • pp.557-573
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    • 2011
  • Let G be a compact and connected semisimple Lie group, H a closed subgroup, g (resp. h) the Lie algebra of G (resp. H), B the Killing form of g, g the normal metric on the homogeneous space G/H which is induced by -B. Let D be an invarint connection with Weyl structure (D, g, ${\omega}$) in the tangent bundle over the normal homogeneous Riemannian manifold (G/H, g) which is projectively flat. Then, the affine connection D on (G/H, g) is a Yang-Mills connection if and only if D is the Levi-Civita connection on (G/H, g).

Blind adaptive receiver for uplink multiuser massive MIMO systems

  • Shin, Joonwoo;Seo, Bangwon
    • ETRI Journal
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    • v.42 no.1
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    • pp.26-35
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    • 2020
  • Herein, we consider uplink multiuser massive multiple-input multiple-output systems when multiple users transmit information symbols to a base station (BS) by applying simple space-time block coding (STBC). At the BS receiver, two detection filters for each user are used to detect the STBC information symbols. One of these filters is for odd-indexed symbols and the other for even-indexed symbols. Using constrained output variance metric minimization, we first derive a special relation between the closed-form optimal solutions for the two detection filters. Then, using the derived special relation, we propose a new blind adaptive algorithm for implementing the minimum output variance-based optimal filters. In the proposed adaptive algorithm, filter weight vectors are updated only in the region satisfying the special relation. Through a theoretical analysis of the convergence speed and a computer simulation, we demonstrate that the proposed scheme exhibits faster convergence speed and lower steady-state bit error rate than the conventional scheme.

ON BOUNDED OPERATOR Qq IN WEIGHT BLOCH SPACE

  • Choi, Ki Seong
    • Journal of the Chungcheong Mathematical Society
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    • v.13 no.1
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    • pp.131-138
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    • 2000
  • Let D be the open unit disk in the complex plane $\mathbb{C}$. For any q > 0, the operator $Q_q$ defined by $$Q_qf(z)=q\int_{D}\frac{f(\omega)}{(1-z{\bar{\omega}})^{1+q}}d{\omega},\;z{\in}D$$. maps $L^{\infty}(D)$ boundedly onto $B_q$ for each q > 0. In this paper, weighted Bloch spaces $\mathcal{B}_q$ (q > 0) are considered on the open unit ball in $\mathbb{C}^n$. In particular, we will investigate the possibility of extension of this operator to the Weighted Bloch spaces $\mathcal{B}_q$ in $\mathbb{C}^n$.

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STRONG CONVERGENCE THEOREMS FOR ASYMPTOTICALLY QUASI-NONEXPANSIVE MAPPINGS AND INVERSE-STRONGLY MONOTONE MAPPINGS

  • He, Xin-Feng;Xu, Yong-Chun;He, Zhen
    • East Asian mathematical journal
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    • v.27 no.1
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    • pp.1-9
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    • 2011
  • In this paper, we consider an iterative scheme for finding a common element of the set of fixed points of a asymptotically quasi nonexpansive mapping and the set of solutions of the variational inequality for an inverse strongly monotone mapping in a Hilbert space. Then we show that the sequence converges strongly to a common element of two sets. Using this result, we consider the problem of finding a common fixed point of a asymptotically quasi-nonexpansive mapping and strictly pseudocontractive mapping and the problem of finding a common element of the set of fixed points of a asymptotically quasi-nonexpansive mapping and the set of zeros of an inverse-strongly monotone mapping.