Search results for "Operative"
showing 10 items of 2781 documents
Multi-agent Systems for Estimating Missing Information in Smart Cities
2019
International audience; Smart cities aim at improving the quality of life of citizens. To do this, numerous ad-hoc sensors need to be deployed in a smart city to monitor the environmental state. Even if nowadays sensors are becoming more and more cheap their installation and maintenance costs increase rapidly with their number. This paper makes an inventory of the dimensions required for designing an intelligent system to support smart city initiatives. Then we propose a multi-agent based solution that uses a limited number of sensors to estimate at runtime missing information in smart cities using a limited number of sensors.
An adaptive cooperative MAC mechanism in multi-hop wireless networks
2010
In this paper, we propose a novel adaptive cooperative MAC mechanism that is specifically designed for two-hop cooperative communications where source and destination cannot hear each other directly. The proposed scheme employs an efficient adaptive relay selection algorithm such that the number of relay nodes is optimized for each cooperative transmission to maximize cooperation benefits and effectively avoid potential collisions with other transmissions. In order to determine the optimal number of relays we apply a training sequence in Hello message exchange, which provides us with a channel status indicator combining both bit-level and flow-level information. Numerical results show that …
A contention-based multiple access protocol in cooperative wireless networks
2010
Cooperative communication has emerged as a promising technique to enhance system performance in wireless networks. This paper proposes a contention-based cooperative multiple medium access control protocol by means of multiple retransmissions of the same packet from different relay nodes. The proposed scheme exploits cooperative communication capability not only from time diversity derived from multiple temporal transmissions but also spatial diversity derived from distributed multiple relays. A Markov chain is introduced to analyze the throughput performance of the proposed cooperative scheme. The performance evaluation of the protocol is validated and compared with non-cooperative ARQ pro…
Concept and setup for intraoperative imaging of tumorous tissue via Attenuated Total Reflection spectrosocopy with Quantum Cascade Lasers
2015
A major challenge in tumor surgery is the differentiation between normal and malignant tissue. Since an incompletely resected tumor easily leads to recidivism, the gold standard is to remove malignant tissue with a sufficient safety margin and send it to pathology for examination with patho-histological techniques (rapid section diagnosis). This approach, however, exhibits several disadvantages: The removal of additional tissue (safety margin) means additional stress to the patient; the correct interpretation of proper tumor excision relies on the pathologist’s experience and the waiting time between resection and pathological result can be more than 45 minutes. This last aspect implies unn…
Parameter optimization for amplify-and-forward relaying systems with pilot symbol assisted modulation scheme
2009
Article published in the journal:Wireless Sensor Network Also available from publisher: http://dx.doi.org/10.4236/wsn.2009.11003 Cooperative diversity is a promising technology for future wireless networks. In this paper, we consider a cooperative communication system operating in an amplify-and-forward (AF) mode with a pilot symbol assisted modulation (PSAM) scheme. It is assumed that a linear minimum mean square estimator (LMMSE) is used for the channel estimation at the receiver. A simple and easy-to-evaluate asymptotical upper bound (AUB) of the symbol-error-rate (SER) is derived for uncoded AF cooperative communication systems with quadrature amplitude modulation (QAM) constellations. …
Cooperative compressive power spectrum estimation in wireless fading channels
2017
This paper considers multiple wireless sensors that cooperatively estimate the power spectrum of the signals received from several sources. We extend our previous work on cooperative compressive power spectrum estimation to accommodate the scenario where the statistics of the fading channels experienced by different sensors are different. The signals received from the sources are assumed to be time-domain wide-sense stationary processes. Multiple sensors are organized into several groups, where each group estimates a different subset of lags of the temporal correlation. A fusion centre (FC) combines these estimates to obtain the power spectrum. As each sensor group computes correlation esti…
What should I do next? Using shared representations to solve interaction problems
2011
Studies on how “the social mind” works reveal that cognitive agents engaged in joint actions actively estimate and influence another’s cognitive variables and form shared representations with them. (How) do shared representations enhance coordination? In this paper, we provide a probabilistic model of joint action that emphasizes how shared representations help solving interaction problems. We focus on two aspects of the model. First, we discuss how shared representations permit to coordinate at the level of cognitive variables (beliefs, intentions, and actions) and determine a coherent unfolding of action execution and predictive processes in the brains of two agents. Second, we discuss th…
Las cooperativas de crédito como entidades colaboradoras de la Administración tributaria
2000
Nowadays the collaboration of private citizens in tax collection management is essential for effective tax collection. For credit cooperatives, collaborating with the State Agency for Tax Administration in tax collection management means public recognition of their ability as financial operators and their economic standing and financial management capability, as well as the possibility of providing more services for their members.
Role of cone-beam computed tomography (CBCT) in diagnosis and treatment planning of two-rooted maxillary lateral incisor with palatogingival groove. …
2020
Background: The embryonic root groove is an anatomical abnormality that starts in the cingulum and extends longitudinally down the long axis root towards the apex. This developmental anomaly is more frequently reported in maxillary lateral incisors. Gu YC in 2011 established three types of radicular grooves depending on its severity. According to this classification, type III presents a greater diagnostic and therapeutic complexity. The prevalence of palatogingival grooves in maxillary lateral incisors ranges from 1.9 to 14%. This case report provides valuable information about the diagnosis and treatment plan of palatogingival grooves with Cone-beam computed tomography (CBCT) scan. Case re…
Symmetry of root and root canal morphology of mandibular incisors: A cone-beam computed tomography study
2019
Background Aim of this study was to analyze the root canal configuration in mandibular central and lateral incisors in vivo using cone-beam computed tomography (CBCT) imaging. Material and methods A total of 487 mandibular central incisors and 491 mandibular lateral incisors from 250 patients were examined using CBCT imaging, previously taken for diagnosis and treatment. The number of roots, root canal system configuration, presence of apical confluences, distance between confluences and radiographic root end, symmetry between left and right elements were recorded and statistically analyzed. Results All the examined teeth presented only one root. No significant differences were found betwee…