The ASTRO-H X-ray Observatory

The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions initiated by the Institute of Space and Astronautical Science (ISAS). ASTRO-H will investigate the physics of the high-energy universe via a suite of four instruments, covering a very wide energy range, from 0.3 keV to 600 keV. These instruments include a high-resolution, high-throughput spectrometer sensitive over 0.3-2 keV with high spectral resolution of Delta E < 7 eV, enabled by a micro-calorimeter array located in the focal plane of thin-foil X-ray optics; hard X-ray imaging spectrometers covering 5-80 keV, located in the focal plane of multilayer-coated, focusing hard X-ray mirrors; a wide-field imaging spectrometer sensitive over 0.4-12 keV, with an X-ray CCD camera in the focal plane of a soft X-ray telescope; and a non-focusing Compton-camera type soft gamma-ray detector, sensitive in the 40-600 keV band. The simultaneous broad bandpass, coupled with high spectral resolution, will enable the pursuit of a wide variety of important science themes.Comment: 22 pages, 17 figures, Proceedings of the SPIE Astronomical Instrumentation "Space Telescopes and Instrumentation 2012: Ultraviolet to Gamma Ray

Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.Comment: Replaced with published version. Added journal reference and DO

Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file

Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks

无线传感器网络，作为全球未来十大技术之一，集成了传感器技术、嵌入式计算技术、分布式信息处理和自组织网技术，可实时感知、采集、处理、传输网络分布区域内的各种信息数据，在军事国防、生物医疗、环境监测、抢险救灾、防恐反恐、危险区域远程控制等领域具有十分广阔的应用前景。 本文研究分析了无线传感器网络的已有路由协议，并针对大规模的无线传感器网络设计了一种树状路由协议，它根据节点地址信息来形成路由，从而简化了复杂繁冗的路由表查找和维护，节省了不必要的开销，提高了路由效率，实现了快速有效的数据传输。 为支持此路由协议本文提出了一种自适应动态地址分配算——ADAR（AdaptiveDynamicAddre...As one of the ten high technologies in the future, wireless sensor network, which is the integration of micro-sensors, embedded computing, modern network and Ad Hoc technologies, can apperceive, collect, process and transmit various information data within the region. It can be used in military defense, biomedical, environmental monitoring, disaster relief, counter-terrorism, remote control of haz...学位：工学硕士院系专业：信息科学与技术学院通信工程系_通信与信息系统学号：2332007115216

Appariement inexact de graphes appliqué à la recherche d'images et d'objets 3D

Les graphes sont des modèles de représentation qui permettent de modéliser un grand nombre de type de documents. Dans cette thèse, nous nous intéressons à leur utilisation pour la recherche dans des bases de données multimédia.Nous commençons par présenter la théorie autour des graphes ainsi qu'un aperçu des méthodes qui ont été proposées pour leur mise en correspondance.Puis, nous nous intéressons plus particulièrement à leur utilisation pour la reconnaissance des formes et l'indexation multimédia.Dans le but de répondre de la manière la plus générique possible aux différents problèmes de recherche, nous proposons de travailler dans le cadre des fonctions noyaux.Ce cadre permet de séparer les problèmes liées à la nature des documents de ceux apportés par les différents types de recherche. Ainsi, toute notre énergie est consacrée à la conception de fonctions de mise en correspondance,mais en gardant à l'esprit qu'elles doivent respecter un certain nombre de propriétés mathématiques. Dans ce cadre, nous proposons de nouvelles solutions qui permettent de mieux répondre aux caractéristiques particulières des graphes issus de primitives et descripteurs visuels. Nous présentons aussi les algorithmes qui permettent d'évaluer rapidement ces fonctions. Enfin, nous présentons des expériences qui mettent en lumière ces différentes caractéristiques, ainsi que des expériences qui montrent les avantages qu'offre nos modèles vis à vis de la littérature.Many type of documents can be modeled by a graph representation. In this thesis, we focus on theuse of graph for research in multimedia databases.We begin by presenting the theory of graphs and aroundan overview of methods that have been proposed for matching.Then, we are particularly interested in their use for recognitionforms and multimedia indexing.In order to respond in the most generic possible differentresearch problems, we propose to work within the framework of kernel functions.This framework allows to separate the problems related to the nature of the documentsthose introduced by the different types of research. Thus, all ourenergy is devoted to the design of mapping functions,but bearing in mind that they must meet a numbermathematical properties. In this context, we propose newsolutions that better meet the specificgraphs from primitive and visual descriptors. Wealso present algorithms to quickly assessthese functions. Finally, wepresent experiments that highlight thesedifferent characteristics and experiences that showadvantages of our models with respect to the literature.CERGY PONTOISE-Bib. electronique (951279901) / SudocSudocFranceF

Recherche d'images par noyaux sur graphes de régions.

National audienceDans le cadre de la recherche interactive d'images dans une base de données, nous nous intéressons à des mesures de similarité d'image qui per- mettent d'améliorer l'apprentissage et utilisables en temps réel lors de la re- cherche. Les images sont représentées sous la forme de graphes d'adjacence de régions floues. Pour comparer des graphes valués nous employons des noyaux de graphes s'appuyant sur des ensembles de chaînes, extraites des graphes compa- rés. Nous proposons un cadre général permettant l'emploi de différents noyaux et différents types de chaînes(sans cycle, avec boucles) autorisant des apparie- ments inexacts. Nous avons effectué des comparaisons sur deux bases issues de Columbia et Caltech et montré que des chaînes de très faible dimension (lon- gueur inférieur à 3) sont les plus efficaces pour retrouver des classes d'objets

Inexact graph matching based on kernels for object retrieval in image databases

International audienceIn the framework of online object retrieval with learning, we address the problem of graph matching using kernel functions. An image is represented by a graph of regions where the edges represent the spatial relationships. Kernels on graphs are built from kernel on walks in the graph. This paper firstly proposes new kernels on graphs and on walks, which are very efficient for graphs of regions. Secondly we propose fast solutions for exact or approximate computation of these kernels. Thirdly we show results for the retrieval of images containing a specific object with the help of very few examples and counter-examples in the framework of an active retrieval scheme

Image retrieval with graph kernel on regions.

International audienceIn the framework of the interactive search in image databases, we are interested in similarity measures able to learn during the search and usable in real-time. Im- ages are represented by adjacency graphs of fuzzy re- gions. In order to compare attributed graphs, we em- ploy kernels on graphs built on sets of paths. In this pa- per, we introduce a fast kernel function whose similar- ity is based on several matches. We also introduce new features for edges in the graph. Experiments on a spe- cific database having objects with heterogeneous back- grounds show the performance of our object retrieval technique