检索结果-内蒙古大学图书馆

25th European signal processing conference (EUSIPCO)

作者： Tabus, Ioan Helin, Petri Tampere Univ Technol Signal Proc Lab POB 553 FI-33101 Tampere Finland

ISBN: (纸本)9780992862671

This paper studies the lossless compressibility of raw sensor images acquired by plenoptic cameras, when optimally interpolating the microlens images in terms of already encoded microlens images. The geometrical information necessary for splitting the sensor image into projections of microlenses, together with a relatively small bitstream for encoding the raw image at the microlens centers are encoded as a first stage. The scanning order for sampling the data from the sensor follows row-by-row the approximate hexagonal lattice pattern of the microlenses, and the pixels inside each microlens are scanned in an ascending spiral order. The predictive encoding of a pixel from a microlens block uses the similarly located pixels (possibly slightly shifted) in the blocks from nine closest causal microlenses (those already encoded) and the pixels from its own microlens located in the encoded part of the spiral. A minimum description length optimal sparse predictor is designed for each microlens. The sparsity masks and prediction coefficients are encoded in a second stage and the prediction errors at every pixel are finally encoded in a third stage, in a view-by-view order (a view index being determined by the pixel's index in its block), using contexts accounting for the magnitude of errors at views already encoded. The experimental results show better performance than the JPEG 2000 image standard applied on the raw image.

关键词： Pixels

来源：评论

学校读者我要写书评

暂无评论

Adaptive Kalman Filter for Tracking of Fast Accelerating targets 14

Adaptive Kalman Filter for Tracking of Fast Accelerating Tar...

引用

14th European Radar conference (EURAD)

作者： Hudec, Premysl Panek, Petr Czech Tech Univ Fac Elect Engn Dept Electromagnet Field Tech 2 Prague 16627 6 Czech Republic Acad Sci Czech Republ Inst Photon & Elect Chaberska 57 Prague 8 Czech Republic

ISBN: (纸本)9782874870491

Active defense (AD) is a new method for protecting military vehicles. Instead of using thick and extremely heavy armors, the actively protected vehicles monitor approaching threatening missiles and de-active them by a suitable active counter-measures. The majority of AD systems is based on radar sensors capable of detecting the concerned missiles and measuring their parameters important for the protective functions. Often, these radar sensors are required to operate in a near-zone (from zero to tens of meters) and find and track relatively small and fast-flying targets. Beside that, it is necessary to take into account the fact that the velocity of the monitored targets can instantaneously vary. This problem especially refers to ignition of rocket engines which can abruptly introduce extremely high accelerations. If the concerned radar sensors employ signal-processing methods based on Kalman filtration, these high-order time-derivatives can cause substantial convergence problems. The main purpose of this article is to present the newly developed adaptable filtering which can reduce these effects. The designed procedures were verified using practically recorded data from flight of RPG-7 missiles.

关键词： Kalman filtration adaptive filtration radar sensor pseudo-noise CW radar

来源：评论

学校读者我要写书评

暂无评论

On the use of deep neural networks for the detection of small vehicles in ortho-images 24

On the use of deep neural networks for the detection of smal...

引用

24th IEEE International conference on Image processing, ICIP 2017

作者： Terrail, Jean Ogier Du Jurie, Frederic Safran Electronics and Defense Normandie Univ UNICAEN ENSICAEN CNRS France Normandie Univ UNICAEN ENSICAEN CNRS France

ISBN: (纸本)9781509021758

This paper addresses the question of the detection of small targets (vehicles) in ortho-images. This question differs from the general task of detecting objects in images by several aspects. First, the vehicles to be detected are small, typically smaller than 20×20 pixels. Second, due to the multifarious-ness of the landscapes of the earth, several pixel structures similar to that of a vehicle might emerge (roof tops, shadow patterns, rocks, buildings), whereas within the vehicle class the inter-class variability is limited as they all look alike from afar. Finally, the imbalance between the vehicles and the rest of the picture is enormous in most cases. Specifically, this paper is focused on the detection tasks introduced by the VEDAI dataset [1]. This work supports an extensive study of the problems one might face when applying deep neural networks with low resolution and scarce data and proposes some solutions. One of the contributions of this paper is a network severely outperforming the state-of-the-art while being much simpler to implement and a lot faster than competitive approaches. We also list the limitations of this approach and provide several new ideas to further improve our results. © 2017 IEEE.

关键词： Deep neural networks

来源：评论

学校读者我要写书评

暂无评论

Preliminary Design of a small Tracking RADAR for LEO Space Objects

Preliminary Design of a Small Tracking RADAR for LEO Space O...

引用

IEEE Aerospace conference

作者： Pecoraro, Giovanni Cianca, Ernestina Marino, Gaetano Ruggieri, Marina Italian Minist Def SICRAL Space Control Ctr Via Raffaele Giacomelli 2 I-00062 Rome Italy Univ Roma Tor Vergata Dept Elect Engn Via Politecn 1 I-00133 Rome Italy

ISBN: (纸本)9781509016136

The near Earth environment has radically changed since the first launch of Sputnik in 1957. So far, the number of uncontrolled artificial objects orbiting around the Earth has incredibly increased and the need of protecting space systems has become almost common to all spacecraft operators. Even though they are currently supported by the large U.S. Space Surveillance Network, most of them have noticed the necessity of creating their own space surveillance sensors. This paper presents a preliminary design of a small and easy to implement radar able to track LEO objects and provide orbits that are more accurate than Two-Line Element (TLE) orbits available online, which do not allow to perform a safe collision avoidance analysis. The adopted configuration is a monostatic pulsed radar with a maximum unambiguous range of 3000 km, a range resolution and angular resolutions of 20 m and 0.01 degrees, respectively. According to the theoretical assessment, the proposed radar is able to detect targets with a Radar Cross Section (RCS) of at least 1 sq. m., which means circular targets with a minimum radius of 50 cm, with a detection probability of 0.9 and a false alarm probability of 0.1. To assess the radar performance, it has been developed CASSIM (Collision Avoidance System SIMulator), which models the system at all stages, from the targets to the signal processing techniques, going through the synthesis of the transmitted and received signals. The simulations have been conducted considering a scenario described in a Collision data Message (CDM) sent by the U.S. Space Surveillance Network. The simulations have involved the less accurate TLE orbit as radar input and the CDM State Vector orbits as reference to model the simulated target. Results have shown that the radar orbit is comparable to the accurate CDM orbit and that the closest approach distance is very similar to the one indicated in the message (less than 30 m error on all components). The analysis presented in this

关键词： Transportation Supply and demand Programming Linear programming Approximation algorithms Resource management

来源：评论

学校读者我要写书评

暂无评论

Supervised Semi-Autoencoder Learning for Multi-Layered Neural Networks 17

Supervised Semi-Autoencoder Learning for Multi-Layered Neura...

引用

Joint 17th World Congress of International-Fuzzy-Systems-Association / 9th International conference on Soft Computing and Intelligent Systems (IFSA-SCIS)

作者： Kamimura, Ryotaro Takeuchi, Haruhiko Tokai Univ IT Educ Ctr 4-1-1 Kitakaname Hiratsuka Kanagawa 2591292 Japan Natl Inst Adv Ind Sci & Technol Human Informat Res Inst 1-1-1 Higashi Tsukuba Ibaraki 3058566 Japan

ISBN: (纸本)9781509049172

The present paper proposes a new type of layer-wise learning for multi-layered neural networks. Multi-layered neural networks have the serious problem of vanishing information, where information contained in input patterns is gradually lost, and preventing neural networks from learning input patterns. In particular, the autoencoders used in the greedy layer-wise pre-training tend to lose the original information by going through multiple layers. For this problem, we propose a new approach called "supervised semi-autoencoder" to solve the problem of vanishing information. The new method is close to the ordinary autoencoder, but the outputs are the original inputs and the corresponding targets for amplifying information in input patterns. In addition, the computational procedures are simplified by using potential learning, in which the potentiality of neurons is determined before learning, and is given as initial weights. Thus, the complicated adjustment of parameters is not necessary. The method was applied to the well-known crab data set as well as the real data set of eye-tracking records. In both cases, with relatively small-sized data, neural networks could find internal representations close to those obtained by larger ones, and better generalization performance could be observed.

关键词： Estimation Field programmable gate arrays OFDM Modulation Filtration Clocks signal processing algorithms

来源：评论

学校读者我要写书评

暂无评论

Towards a Renewed Alias Resolution with Space Search Reduction and IP Fingerprinting 1

Towards a Renewed Alias Resolution with Space Search Reducti...

引用

1st Network Traffic Measurement and Analysis conference (TMA)

作者： Grailet, Jean-Francois Donnet, Benoit Univ Liege Montefiore Inst Liege Belgium

ISBN: (纸本)9783901882951

Since the early 2000' s, the Internet Topology has been frequently described and modeled from the perspective of routers. To this end, alias resolution mechanisms have been developed in order to aggregate all IP interfaces of a router, collected with traceroute, into a single identifier. So far, many active measurement techniques have been considered, often taking advantage of specific features from network protocols. However, a lot of these methods have seen their efficiency decrease over time due to security reinforcements across the Internet. In this paper, we introduce a generic methodology to conduct efficient and scalable alias resolution. It combines the space search reduction of TreeNET (a tool for efficiently discovering subnets) with a fingerprinting process used to assess the feasibility of several state-of-the-art alias resolution methods, using a small, fixed amount of probes. We validate our method along MIDAR on an academic groundtruth and demonstrate that our methodology can achieve similar accuracy while using less probes and discovering subnets in the process. We further evaluate our method with measurements made on PlanetLab towards several distinct ASes of varying sizes and roles in the Internet. The collected data shows that some properties of our fingerprints correlate with each other, hinting some observed profiles could be linked with equipment vendors. Both TreeNET (which implements our methodology) and our dataset are freely available.

关键词： Estimation Field programmable gate arrays OFDM Modulation Filtration Clocks signal processing algorithms

来源：评论

学校读者我要写书评

暂无评论

Multi-channel quasi-adaptive processing based on low and slow targets in complex environment

引用

AIP conference Proceedings 2018年第1期1967卷

作者： Tonghui Xue Tao Shan Yuan Feng Beijing Institute of Technology Beijing China

Because there are many kinds of clutter interference in the detection of low and slow small targets, clutter suppression is always an important issue in radar signal processing. In this paper, clutter in complex environment is first analyzed based on a large amount of measured data, In theory, the clutter suppression algorithm with narrow spectral width and broad spectrum width is effectively studied: the weighted mean filter algorithm and the noise subspace algorithm, and the improved algorithm of weighted mean filter is proposed. Secondly, Multi-channel quasi-adaptive clutter suppression filter, simple and practical, can effectively suppress clutter in complex environments, and the algorithm is implemented, verified by the measured data, and confirmed good results.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Adaptive Kalman filter for tracking of fast accelerating targets

Adaptive Kalman filter for tracking of fast accelerating tar...

引用

European Radar conference (EURAD)

作者： Premysl Hudec Petr Panek Department of Electromagnetic Field Czech Technical University in Prague Prague 6 Czech Republic Academy of Sciences of the Czech Republic Institute of Photonics and Electronics Czech Republic

关键词： Standards Estimation Radar Kalman filters Missiles Sensors Engines

来源：评论

学校读者我要写书评

暂无评论

GMTI in circular SAR data using STAP 6

GMTI in circular SAR data using STAP

引用

conference on Sensor signal processing for Defence (SSPD)

作者： Casalini, Emiliano Henke, Daniel Meier, Erich Univ Zurich Remote Sensing Labs CH-8006 Zurich Switzerland

ISBN: (纸本)9781509003266

This paper presents method and results of a Ground Moving Target Indication (GMTI) experiment using multichannel Synthetic Aperture Radar (M-SAR) data collected by the four channel F-SAR system. The proposed approach is based on sub-aperture processing, Space-Time Adaptive processing (STAP), constant false alarm rate (CFAR) thresholding and geocoding. The results are validated and compared with results of the same data set from a previous approach based on a combination of single-channel (SC) and Along-Track Interferometry (ATI) detections. It is shown that the STAP-based technique guarantees better performances when detecting moving targets with a small Radar Cross Section (RCS).

关键词： Space time adaptive processing

来源：评论

学校读者我要写书评

暂无评论

Microlens Image Sparse Modelling for Lossless Compression of Plenoptic Camera Sensor Images

Microlens Image Sparse Modelling for Lossless Compression of...

引用

European signal processing conference

作者： Ioan Tabus Petri Helin Tampere University of Technology Laboratory of Signal Processing Tampere Finland

关键词： Lenses Microoptics Spirals Image coding Cameras Lattices Indexes

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：