Time Allocation of a Set of Radars in a Multitarget Environment

International audienceThe question tackled here is the time allocation of radars in a multitarget environment. At a given time radars can only observe a limited part of the space; it is therefore necessary to move their axis with respect to time, in order to be able to explore the overall space facing them. Such sensors are used to detect, to locate and to identify targets which are in their surrounding aerial space. In this paper we focus on the detection schema when several targets need to be detected by a set of delocalized radars. This work is based on the modelling of the radar detection performances in terms of probability of detection and on the optimization of a criterion based on detection probabilities. This optimization leads to the derivation of allocation strategies and is made for several contexts and several hypotheses about the targets locations

Radar Optimal Times Detection Allocation in Multitarget Environment

International audienceThis paper deals with the problem of the management of Electronically Steered Antenna (ESA) in multitarget environments. Radars are used to detect, locate and identify targets. In this paper we focus on the detection of several aerial targets in a fixed given time. The difficulty of such detection lies in the fact that targets may be located anywhere in the space, but radars can only observe a limited part of it at a time. As a result, it is necessary to change their axis position over time. This paper describes the main steps to derive an optimal radar management in this context: the modeling of the radar, the determination of a criterion based on the target detection probability and the temporal optimization process leading to sensor management strategy. An optimization solution is presented for several contexts and several hypotheses about prior knowledge concerning the targets' locations. First, we propose a method for the optimization of the radar detection probability in a single target environment. It consists in the decomposition of the detection step into an optimal number of independent elementary detections. Then, in a multitarget context with deterministic prior knowledge, we present an optimal time allocation method which is based on the results of non linear programming. Finally, in a multitarget context with probabilistic prior knowledge, results in Search Theory are used to determine an optimal temporal allocation

PatSeeding: A Standalone Track Reconstruction Algorithm

A standalone pattern recognition algorithm for the LHCb T stations is presented. Its performance on B_d --> J/psi K_s and minimum bias Monte Carlo events is evaluated, and tunings for reconstruction without magnetic field, with misalignments or for reconstruction of cosmics are shown. Furthermore, this notes describes changes to the algorithm which make it suitable for trigger applications, especially for Level 0 confirmation (the performance of these modifications is evaluated in an upcoming LHCb note)

An SNMP-based audio distribution service architecture

Dissertação de mestrado em Engenharia de Redes e Serviços TelemáticosThe constant growth of integration and popularity of “Internet of Things” devices is affecting home automation systems, where new technologies were introduced, in the recent years for this particular sector. These automation systems integrate devices that can be anywhere in the house, connected to a home network, either through a wire or wireless connection. A home automation system can be used to control air conditioning, lighting, pool control systems, home-entertainment systems and much more. Within the field of home-entertainment systems, the best known technologies are the Digital Living Network Alliance and the Digital Audio Access Protocol, which provide interoperability to allow sharing of digital media content between devices across a home network. However, these technologies have the disadvantage of being proprietary, maintaining restrict documentation access, complex architectures and concepts and not optimal to specific purposes, like audio distribution. The main goal of this project was to prove that is possible to use standardized protocols, such as the Simple Network Manager Protocol and open source tools in order to develop a music distribution service that allows the implementation of similar features than the ones already existing proprietary technologies. As such, the implementation prototype system allows a user to manage and play audio from a music collection that is stored in a single home audio server. The system architecture enables audio streaming between the server and the various devices in the same local network. Further more, the music collection, can integrate virtual audio files that are available from external music sources, like iTunes, etc.O constante crescimento de integração e popularidade da “Internet das coisas” tem atualmente afetado sistemas de domótica, onde cada vez mais tecnologias têm vindo a ser desenvolvidas nos últimos anos para este sector em particular. Estes sistemas de domótica integram dispositivos que podem estar em qualquer parte de uma casa, ligados à rede seja através de um cabo ou por wireless. Um sistema de domótica pode ser usado para controlar: ar condicionado, iluminação, sistemas de controlo de piscinas, sistemas de entretenimento, entre outros. Na área de sistemas de entretenimento, as tecnologias mais conhecidas são Digital Living Network Alliance e Digital Audio Access Protocol, que fornecem interoperabilidade de modo a permitir a partilha de conteúdos digitais multimédia entre dispositivos que se encontram na mesma rede local. Contudo, possuem a desvantagem de serem tecnologias proprietárias, com documentação e manuais restritos, arquiteturas e conceitos complexos, e não otimizados para fins específicos, tal distribuição de áudio. O principal objetivo deste projeto foi provar que é possível usar protocolos normalizados, como o Simple Network Manager Protocol e ferramentas open source de forma a desenvolver um serviço de distribuição de música que permite a implementação de funcionalidades semelhantes às tecnologias proprietárias já existentes. Assim, o protótipo implementado permite a um utilizador gerir e reproduzir áudio de uma coleção de música que se esteja armazenada num servidor de áudio domestico. A arquitetura permite streaming de áudio entre o servidor e os diferentes dispositivos que se encontram na mesma rede local. Consequentemente, a coleção de música pode integrar ficheiros de áudio visuais que estejam acessíveis através de fontes externas de música, como por exemplo: iTunes, etc

Poplar plantations in Turkey: an overlooked habitat for orchids

Turkey’s orchid flora is one of the richest in the Mediterranean region, but is also under threat from intensification of agriculture, land-use change, habitat loss, overgrazing and salep harvesting (tuber collection). With this study, we would like to draw attention to the importance of economic poplar plantations as orchid habitats. In six of the eight plantations surveyed in five provinces of Turkey, altogether 12 orchid species (Anacamptis elegans, A. fragrans, A. pyramidalis, Cephalanthera longifolia, C. damasonium, Epipactis helleborine, E. persica, Himantoglossum jankae, Ophrys apifera, O. oestrifera, Ophrys sp., Serapias feldwegiana) were found. In the plantations with an average area of only 0.27 ± 0.21 hectares, the presence of 0–5 orchid species was recorded (mean ± SD = 1.88 ± 1.80). The density of orchid populations varied from 0 to 355.6 specimens per hectare. Both tuberous and rhizomatous orchids were encountered in the studied plantations, but the former ones were dominant: 8 species (67%) and 232 specimens (94%) of the studied orchids were tuberous. The average trunk diameter in poplar plantations harboring orchids ranged from 16.7 to 21.8 cm. In the surveyed plantations, there were no traces of tuber harvesting or overgrazing, which may contribute to their suitability as habitat for orchids. Considering the recent extent of poplar plantations and their expected further increase in Turkey, studying their role in orchid conservation seems important and timely

Citation Analysis of serials in Postgraduate Theses and Dissertations of Library and Information Science of Public Universities in Southeast, Nigeria

This study is a citation analysis of serials in postgraduate Theses and dissertations of library and information science of public universities in Southeast Nigeria submitted from 2013 to 2021. The study was guide by five research questions in line with the objectives of the study. The study employed a descriptive survey design with a sampled population of 296 derived through census method from four public universities offering library and information science. The principle instruments used in collecting data for this study were self-designed checklists. With the checklists, 12455 serials citations were analyzed using descriptive statistics of mode, mean and range and data presented in tables, charts and graphs using frequencies and percentile. . The study found that the most cited serials types were journals with 76.5% citations followed by conference proceedings/reports with 20% and the least cited being government publication with only .5 citations . This affirms other citation analysis, which found that journals are the most frequently used type. It was further discovered that serials used were either in print or electronic form. . The study also revealed that multi authorship is the most frequently cited author pattern in library graduates theses and dissertations, while annual serials citations range from 1034 to 2205. The study indicated that the average age of serials used was 0 - 20. The study recommended among other things that there should be documentation librarian in each university library whose duty should be tracking down research reports, ensuring proper documentations and upward delivery to the university library circulation unit

Learning to locate from demonstrated searches

Abstract—We consider the problem of learning to locate targets from demonstrated searches. In this concept, a human demonstrates tours of environments that are assumed to minimize the human’s expected time to locate the target, given the person’s latent prior over potential target locations. The latent prior is then learned as a function of environmental features, enabling a robot to search novel environments in a way that would be deemed efficient by the teacher. We present novel approaches to solve both the inference problem of planning an expected-time-optimal tour given a prior and the learning problem of deducing the prior from observed tours. Our learning algorithm is inspired by and similar to maximum margin planning (MMP), although it differs in key ways. On the inference side, we advance the state-of-the-art by proposing novel relaxations that are integrated into a heuristic-driven search algorithm. An application to a home assistant scenario is discussed, and experimental results are given validating our methods in this domain. I

Bayesian Search Under Dynamic Disaster Scenarios

Search and Rescue (SAR) is a hard decision making context where there is available a limited amount of resources that should be strategically allocated over the search region in order to find missing people opportunely. In this thesis, we consider those SAR scenarios where the search region is being affected by some type of dynamic threat such as a wilder or a hurricane. In spite of the large amount of SAR missions that consistently take place under these circumstances, and being Search Theory a research area dating back from more than a half century, to the best of our knowledge, this kind of search problem has not being considered in any previous research. Here we propose a bi-objective mathematical optimization model and three solution methods for the problem: (1) Epsilon-constraint; (2) Lexicographic; and (3) Ant Colony based heuristic. One of the objectives of our model pursues the allocation of resources in riskiest zones. This objective attempts to find victims located at the closest regions to the threat, presenting a high risk of being reached by the disaster. In contrast, the second objective is oriented to allocate resources in regions where it is more likely to find the victim. Furthermore, we implemented a receding horizon approach oriented to provide our planning methodology with the ability to adapt to disaster's behavior based on updated information gathered during the mission. All our products were validated through computational experiments.MaestríaMagister en Ingeniería Industria