• Title/Summary/Keyword: Gray mapping

Search Result 66, Processing Time 0.025 seconds

A Study on the Structure of Turbo Trellis Coded Modulation with an Effectively Reduced Complexity in Wireless Communication Channel (무선통신채널에서 효과적으로 감소된 복잡도를 갖는 Turbo Trellis Coded Modulation 구조 연구)

  • Kim Jeong-su
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.5 no.5
    • /
    • pp.409-412
    • /
    • 2004
  • This paper shows that the proposed Turbo TCM(Turbo Trellis Coded Modulation) has a good performance with a little complexity of decoder. The encoder structure, which is connected with Turbo Codes, is the proposed modulation technique for an efficient bandwidth, This method is used symbol by symbol MAP decoder of iteration similar to binary Turbo Codes in the receiver. The result shows that the BER performance according to iteration is improved about 2,5dB at $BER=10^{-2}$ compared to Turbo Codes with Gray mapping.

  • PDF

Topographic Brain Map of Multi-Channel EEG by Spectrum Analysis Method (스펙트럼 해석방법에 의한 다중찬넬 뇌파의 Topographic Brain Map)

  • 유선국;고한우
    • Journal of Biomedical Engineering Research
    • /
    • v.9 no.1
    • /
    • pp.31-36
    • /
    • 1988
  • A personal computer-based brain map is described which will display a gray scale maps showing the distribution of signals derived from the electrical activity of the brain such as EEG or EP This topographic brain mapping system has a flexibility which describe the electrode number and placement mapping onto any shaped space and generate a brain maps by incoorporated the data acquisition and processing software with conventional EEG machine.

  • PDF

Fuzzy Classifier System for Edge Detection

  • Sim, Kwee-Bo
    • International Journal of Fuzzy Logic and Intelligent Systems
    • /
    • v.3 no.1
    • /
    • pp.52-57
    • /
    • 2003
  • In this paper, we propose a Fuzzy Classifier System(FCS) to find a set of fuzzy rules which can carry out the edge detection. The classifier system of Holland can evaluate the usefulness of rules represented by classifiers with repeated learning. FCS makes the classifier system be able to carry out the mapping from continuous inputs to outputs. It is the FCS that applies the method of machine learning to the concept of fuzzy logic. It is that the antecedent and consequent of classifier is same as a fuzzy rule. In this paper, the FCS is the Michigan style. A single fuzzy if-then rule is coded as an individual. The average gray levels which each group of neighbor pixels has are represented into fuzzy set. Then a pixel is decided whether it is edge pixel or not using fuzzy if-then rules. Depending on the average of gray levels, a number of fuzzy rules can be activated, and each rules makes the output. These outputs are aggregated and defuzzified to take new gray value of the pixel. To evaluate this edge detection, we will compare the new gray level of a pixel with gray level obtained by the other edge detection method such as Sobel edge detection. This comparison provides a reinforcement signal for FCS which is reinforcement learning. Also the FCS employs the Genetic Algorithms to make new rules and modify rules when performance of the system needs to be improved.

The example of face mapping on rock slope at Chubu-Daejeon national road (옥천계 분포지 추부-대전 간 국도 대절토 사면의 Face Mapping 사례)

  • Lee, Byung-Joo;Chae, Byung-Gon;Lee, Kyoung-Mi
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2006.03a
    • /
    • pp.51-60
    • /
    • 2006
  • At new constructing national road, a cutting slope was surveyed and gotten face mapping for three months. The slope is composed of gray phyllite and coaly slate which is the Chang-ri Formation, Okcheon system. The slope angle is 40 degree and the direction is NNE. The attitude of schistosity is $260^{\circ}/45^{\circ}$. So the slope direction is nearly parallel to the schistosity. This is the reason that the slope is very unstable. On the other hand, the very unstable slope is caused by the direction of the schistosity and the slope. First month the coaly slate was slided through the schistosity plane about 10cm. However, three months late the displacement was 2m maximum.

  • PDF

COLOR CORRECTION METHOD USING GRAY GRADIENT BAR FOR MULTI-VIEW CAMERA SYSTEM

  • Jung, Jae-Il;Ho, Yo-Sung
    • Proceedings of the Korean Society of Broadcast Engineers Conference
    • /
    • 2009.01a
    • /
    • pp.1-6
    • /
    • 2009
  • Due to the different camera properties of the multi-view camera system, the color properties of captured images can be inconsistent. This inconsistency makes post-processing such as depth estimation, view synthesis and compression difficult. In this paper, the method to correct the different color properties of multi-view images is proposed. We utilize a gray gradient bar on a display device to extract the color sensitivity property of the camera and calculate a look-up table based on the sensitivity property. The colors in the target image are converted by mapping technique referring to the look-up table. Proposed algorithm shows the good subjective results and reduces the mean absolute error among the color values of multi-view images by 72% on average in experimental results.

  • PDF

New Construction Method for Quaternary Aperiodic, Periodic, and Z-Complementary Sequence Sets

  • Zeng, Fanxin;Zeng, Xiaoping;Zhang, Zhenyu;Zeng, Xiangyong;Xuan, Guixin;Xiao, Lingna
    • Journal of Communications and Networks
    • /
    • v.14 no.3
    • /
    • pp.230-236
    • /
    • 2012
  • Based on the known binary sequence sets and Gray mapping, a new method for constructing quaternary sequence sets is presented and the resulting sequence sets' properties are investigated. As three direct applications of the proposed method, when we choose the binary aperiodic, periodic, and Z-complementary sequence sets as the known binary sequence sets, the resultant quaternary sequence sets are the quaternary aperiodic, periodic, and Z-complementary sequence sets, respectively. In comparison with themethod proposed by Jang et al., the new method can cope with either both the aperiodic and periodic cases or both even and odd lengths of sub-sequences, whereas the former is only fit for the periodic case with even length of sub-sequences. As a consequence, by both our and Jang et al.'s methods, an arbitrary binary aperiodic, periodic, or Z-complementary sequence set can be transformed into a quaternary one no matter its length of sub-sequences is odd or even. Finally, a table on the existing quaternary periodic complementary sequence sets is given as well.

NOMA Transceiver Design for Highway Transportation in Mobile Hotspot Networks

  • Hui, Bing;Kim, Junhyeong;Choi, Sung-Woo;Chung, Heesang;Kim, Ilgyu;Lee, Hoon
    • ETRI Journal
    • /
    • v.38 no.6
    • /
    • pp.1042-1051
    • /
    • 2016
  • The mobile hotspot network (MHN), which is capable of providing a data rate of gigabits per second at high speed, is considered a potential use case of the future enhanced mobile broadband for 5G. Because a unidirectional network deployment has been considered for an MHN, non-orthogonal multiple access (NOMA) can be employed to improve the system performance. For a practical implementation of NOMA under an MHN highway scenario where multiple pieces of MHN terminal equipment are served through the same beam simultaneously, a NOMA transceiver is proposed in this paper. For the NOMA transmitter, Gray-coded QAM constellation mapping is extended to arbitrary modulation order q. For the NOMA receiver, successive interference cancellation (SIC) is no longer necessary, and instead, a parallel demodulation is proposed. The numerical and simulation results suggest that the proposed NOMA transceiver outperforms the conventional NOMA SIC receiver and can be flexibly used for an MHN highway scenario.

Mapping Vegetation Volume in Urban Environments by Fusing LiDAR and Multispectral Data

  • Jung, Jinha;Pijanowski, Bryan
    • Korean Journal of Remote Sensing
    • /
    • v.28 no.6
    • /
    • pp.661-670
    • /
    • 2012
  • Urban forests provide great ecosystem services to population in metropolitan areas even though they occupy little green space in a huge gray landscape. Unfortunately, urbanization inherently results in threatening the green infrastructure, and the recent urbanization trends drew great attention of scientists and policy makers on how to preserve or restore green infrastructure in metropolitan area. For this reason, mapping the spatial distribution of the green infrastructure is important in urban environments since the resulting map helps us identify hot green spots and set up long term plan on how to preserve or restore green infrastructure in urban environments. As a preliminary step for mapping green infrastructure utilizing multi-source remote sensing data in urban environments, the objective of this study is to map vegetation volume by fusing LiDAR and multispectral data in urban environments. Multispectral imageries are used to identify the two dimensional distribution of green infrastructure, while LiDAR data are utilized to characterize the vertical structure of the identified green structure. Vegetation volume was calculated over the metropolitan Chicago city area, and the vegetation volume was summarized over 16 NLCD classes. The experimental results indicated that vegetation volume varies greatly even in the same land cover class, and traditional land cover map based above ground biomass estimation approach may introduce bias in the estimation results.

A Voxel-Based Morphometry of Gray Matter Reduction in Patients with Dementia of the Alzheimer's Type (화소 기반 형태분석 방법을 이용한 알츠하이머 치매환자의 회백질 용적감소의 정량적 분석)

  • Lim, Hyun-Kook;Choi, Eun-Hyung;Lee, Chang-Uk
    • Korean Journal of Biological Psychiatry
    • /
    • v.15 no.2
    • /
    • pp.118-125
    • /
    • 2008
  • Objectives : The purpose of this study was to find brain regions in which gray matter volume was reduced and to show the capability of voxel-based morphpmetry(VBM) analysis for lateralizing clinically significant brain regions in dementia of Alzheimer's type patients compared to healthy group. Methods : MR T1-weighted images of the 20 dementia of Alzheimer's type patients were compared with those of the 20 normal controls. Images were transformed to standard MNI space. In order to observe gray matter volume change. Gray matter was smoothed with a Gaussian kernel. After these preprocessing, statistical analysis was performed using statistical parametric mapping software(SPM2). Results : Gray matter volume was significantly reduced in the bilateral parahippocampal gyri, Lt. anterior cingulate gyrus, Lt. posterior cingulate gyrus, bilateral superior temporal gyri Lt. middle temporal gyrus, Lt. superior, bilateral middle, Rt. anterior frontal gyri and Rt. precuneus in dementia of Alzheimer's type patient group. Conclusions : These VBM results confirm previous findings of temporal lobe and limbic lobe atrophic changes in dementia of Alzheimer's type, and suggest that these abnormalities may be confined to specific sites within that lobe, rather than showing a widespread distribution.

  • PDF

A voxel based morphometry study in Alzheimer's disease

  • Rahyeong Juh;Taesuk Suh;Boyoung Choe;Lee, Changuk
    • Proceedings of the Korean Society of Medical Physics Conference
    • /
    • 2003.09a
    • /
    • pp.46-46
    • /
    • 2003
  • Several MRI studies have reported reductions in temporal lobe volumes in Alzheimer´s disease (AD). Measures have been usually obtained with regions of interest (ROI) drawn manually on selected medial and lateral portions of the temporal lobes, with variable choices of anatomical borders across different studies. We used the automated voxel based morphometry (VBM) approach to investigate gray matter abnormalities over the entire extension of the temporal lobe in 11 AD patients (MMSE 14 - 25) and 11 healthy controls. Foci of significantly reduced gray matter volume in AD patients were detected in both medial and lateral temporal regions, most significantly in the right and left posterior parahippocampal gyri. At a more flexible statistical threshold (P<0.001, uncorrected for multiple comparisons), circumscribed foci of significant gray matter reduction were also detected in the right amygdala/enthorinal cortex, the anterior and posterior borders of the superior temporal gyrus bilaterally, and the anterior portion of the left middle temporal gyrus. These VBM results confirm previous findings of temporal lobe atrophic changes in AD, and suggest that these abnormalities may be confined to specific sites within that lobe, rather than showing a widespread distribution.

  • PDF