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Formation control of Surface Marine Vehicles for Underwater Target Tracking Using Range Information

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Formation Control of Surface Marine Vehicles for Underwater ...

APCA International Conference on automatic control and Soft Computing (controlO)

作者： D. Moreno-Salinas N. Crasta A.M. Pascoal J. Aranda Dept. of Computer Science and Automatic Control National Distance Education University Madrid Spain Department of Electrical Engineering ISR/IST University of Lisbon Lisbon Portugal

In many of the marine applications, the availability of an accurate system to localize underwater targets using a group of surface vehicles equipped with acoustic sensors is of paramount importance. In this context, the surface vehicles must keep a well-defined formation with respect to the targets so as to maximize the range-based information available for target localization. In this paper, a target position estimation algorithm together with a simple formation control law to maintain an optimal configuration that maximizes range-related information for target localization and tracking are presented. The setup studied consists of a group of surface vehicles moving in formation and a target performing a predefined mission. The optimal formation is computed by maximizing the determinant of an appropriately defined Fisher information matrix (FIM), subject to inter-vehicle collision avoidance and vehicle manoeuvring constraints. A centralized approach for the formation control is considered, where the trajectory planning is carried out by a supervisor that computes the control actions for each agent. The formation control is complemented with a collision avoidance logic based on a discrete event law. Simulations show that this strategy leads to an interesting and well defined behavior of the formation for localization and tracking.

关键词： Target tracking Collision avoidance Robot sensing systems Estimation Position measurement Mobile robots

Using Cloud and Mobile Technologies in the Hospitality Industry

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Using Cloud and Mobile Technologies in the Hospitality Indus...

Roedunet International Conference (RoEduNet)

作者： Ioan - Radu JINGA Laurentiu-Florin BOTEZATU Ioana CULIC Alexandru RADOVICI Faculty of Automatic Control and Computer “Politehnica” University of Bucharest Bucharest Romania Faculty of Engineering in Foreign Languages “Politehnica” University of Bucharest Bucharest Romania Research Department Wyliodrin Bucharest Romania Department of Computer Engineering “Politehnica” University of Bucharest Bucharest Romania

Although the expansion rate of the technology mixed with other domains is growing, restaurant industry has, on average, little to no technical solutions for the common problems of their business. A specific problem is the time consuming and ineffective methods of calculating the bill for every person at the table. In this paper, we describe an automatic and efficient solution for this problem, a platform that digitally extracts the products from the bill, no matter the structure of it and allows users to select the items they ordered.

关键词： Optical character recognition software Mobile applications Google History Real-time systems Industries Libraries

automatic language identification for romance languages using stop words and diacritics: Tool/experimental paper

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arXiv 2018年

作者： Truicǎ, Ciprian-Octavian Velcin, Julien Boicea, Alexandru Computer Science and Engineering Department Faculty of Automatic Control and Computers University Politehnica of Bucharest Bucharest Romania University of Lyon ERIC Laboratory Lyon 2 Lyon France

automatic language identification is a natural language processing problem that tries to determine the natural language of a given content. In this paper we present a statistical method for automatic language identification of written text using dictionaries containing stop words and diacritics. We propose different approaches that combine the two dictionaries to accurately determine the language of textual corpora. This method was chosen because stop words and diacritics are very specific to a language, although some languages have some similar words and special characters they are not all common. The languages taken into account were romance languages because they are very similar and usually it is hard to distinguish between them from a computational point of view. We have tested our method using a Twitter corpus and a news article corpus. Both corpora consists of UTF-8 encoded text, so the diacritics could be taken into account, in the case that the text has no diacritics only the stop words are used to determine the language of the text. The experimental results show that the proposed method has an accuracy of over 90% for small texts and over 99.8% for large texts. Copyright © 2018, The Authors. All rights reserved.

关键词： Natural language processing systems

BCCNet: Bayesian classifier combination neural network

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arXiv 2018年

作者： Isupova, Olga Li, Yunpeng Kuzin, Danil Roberts, Stephen J. Willis, Katherine Reece, Steven Department of Engineering Science University of Oxford United Kingdom Department of Computer Science University of Surrey United Kingdom Department of Automatic Control and Systems Engineering University of Sheffield United Kingdom Department of Zoology University of Oxford United Kingdom

Machine learning research for developing countries can demonstrate clear sustainable impact by delivering actionable and timely information to in-country government organisations (GOs) and NGOs in response to their critical information requirements. We co-create products with UK and in-country commercial, GO and NGO partners to ensure the machine learning algorithms address appropriate user needs whether for tactical decision making or evidence-based policy decisions. In one particular case, we developed and deployed a novel algorithm, BCCNet, to quickly process large quantities of unstructured data to prevent and respond to natural disasters. Crowdsourcing provides an efficient mechanism to generate labels from unstructured data to prime machine learning algorithms for large scale data analysis. However, these labels are often imperfect with qualities varying among different citizen scientists, which prohibits their direct use with many state-of-the-art machine learning techniques. We describe BCCNet, a framework that simultaneously aggregates biased and contradictory labels from the crowd and trains an automatic classifier to process new data. Our case studies, mosquito sound detection for malaria prevention and damage detection for disaster response, show the efficacy of our method in the challenging context of developing world applications. Copyright © 2018, The Authors. All rights reserved.

关键词： Developing countries

Steady-state analysis of a neural-cognition based human-social behavior model

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arXiv 2018年

作者： Wei, Jieqiang Nekouei, Ehsan Wu, Junfeng Cvetkovic, Vladimir Johansson, Karl H. Department of Automatic Control School of Electrical Engineering and Computer Science KTH Royal Institute of Technology StockholmSE-100 44 Sweden College of Control Science and Engineering Zhejiang University Hangzhou China School of Architecture and the Built Environment

We consider an extension of the Rescorla-Wagner model which bridges the gap between conditioning and learning on a neural-cognitive, individual psychological level, and the social population level. In this model, the interaction among individuals is captured by a Markov process. The resulting human-social behavior model is a recurrent iterated function systems which behaves differently from the classical Rescorla- Wagner model due to randomness. Convergence and ergodicity properties of the internal states of agents in the proposed model are studied. Copyright © 2018, The Authors. All rights reserved.

关键词： Decision making

Trajectory generation using sharpness continuous dubins-like paths with applications in control of heavy-duty vehicles

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arXiv 2018年

作者： Oliveira, Rui Lima, Pedro F. Cirillo, Marcello Mårtensson, Jonas Wahlberg, Bo Department of Automatic Control School of Electrical Engineering and Computer Science KTH Royal Institute of Technology Stockholm Sweden Scania Autonomous Transport Solutions Södertälje Sweden

We present a trajectory generation framework for control of wheeled vehicles under steering actuator constraints. The motivation is smooth driving of autonomous heavy-duty vehicles, which are characterized by slow actuator dynamics. In order to deal with the slow dynamics, we take into account rate and, additionally, torque limitations of the steering actuator directly. Previous methods only take into account limitations in the path curvature, which deals indirectly with steering rate limitations. We propose the new concept of Sharpness Continuous curves, which uses cubic curvature paths together with circular arcs to steer the vehicle. The obtained paths are characterized by a smooth and continuously differentiable steering angle profile. The final trajectories computed with our method provide low-level controllers with reference signals which are easier to track, resulting in improved performance. The smoothness of the obtained steering profiles also results in increased passenger comfort. The method is characterized by fast computation times. We detail possible path planning applications of the method, and conduct simulations that show its advantages and real-time capabilities. Copyright © 2018, The Authors. All rights reserved.

关键词： Motion planning

Affine Formation Maneuver control of Multi-Agent Systems with Directed Interaction Graphs

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Affine Formation Maneuver Control of Multi-Agent Systems wit...

Chinese control Conference

作者： Yang Xu Shiyu Zhao Delin Luo Yancheng You Department of Electrical and Computer Engineering National University of Singapore Singapore Singapore Department of Automatic Control and Systems Engineering University of Sheffield Sheffield United Kingdom School of Aerospace Engineering Xiamen University Xiamen P. R. China

The affine formation maneuver control problem of a leader-follower type multi-agent systems with the directed interaction graphs is studied in this paper. This paper firstly gives and proves a sufficient and necessary condition of achieving the affine localizability. Then, under the (d + 1)-reachable condition of the given d-dimensional nominal formation with d + 1 leaders, a formation of agents can be reshaped in arbitrary dimension by only controlling these leaders. In the sequel, a novel distributed control method for the followers with single-integrator dynamics is proposed to achieve the desired time-varying maneuvers, and the global stability is also proved. Corresponding simulations are carried out to verify the theoretical results, which show that these followers are tracking the time-varying references accurately and continuously.

关键词： Laplace equations Multi-agent systems Decentralized control Aerospace electronics Electronic mail Task analysis Target tracking

Optimal weight allocation of dynamic distribution networks and positive semi-definiteness of signed laplacians

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arXiv 2018年

作者： Wei, Jieqiang Johansson, Alexander Sandberg, Henrik Johansson, Karl H. Chen, Jie Department of Automatic control School of Electrical Engineering and Computer Science KTH Royal Institute of Technology StockholmSE-100 44 Sweden Department of Electronic Engineering City University of Hong Kong Hong Kong Hong Kong

In this paper, we consider the robustness of a basic model of a dynamical distribution network. In the first problem, i.e., optimal weight allocation, we minimize the H∞- norm of the dynamical distribution network subject to allocation of the weights on the edges. It is shown that this optimization problem can be formulated as a semi-definite program. Next we consider the semi-definiteness of the weighted graph Laplacian matrix with negative weights on the edges. A necessary and sufficient condition, using the effective resistance matrix, is established to guarantee the positive semi-definiteness of the Laplacian matrix. Furthermore, the bounded real lemma is derived for state-space symmetric systems. Copyright © 2018, The Authors. All rights reserved.

关键词： Laplace transforms

Benchmarking top-k keyword and top-k document processing with T2K2and T2K2D2

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arXiv 2018年

作者： Truicǎ, Ciprian-Octavian Darmont, Jérôme Boicea, Alexandru Rǎdulescu, Florin Computer Science and Engineering Department Faculty of Automatic Control and Computers University Politehnica of Bucharest Bucharest Romania Université de Lyon ERIC EA Lyon 23083 France

Top-k keyword and top-k document extraction are very popular text analysis techniques. Top-k keywords and documents are often computed on-the-fly, but they exploit weighted vocabularies that are costly to build. To compare competing weighting schemes and database implementations, benchmarking is customary. To the best of our knowledge, no benchmark currently addresses these problems. Hence, in this paper, we present T2K2, a top-k keywords and documents benchmark, and its decision support-oriented evolution T2K2D2. Both benchmarks feature a real tweet dataset and queries with various complexities and selectivities. They help evaluate weighting schemes and database implementations in terms of computing performance. To illustrate our benchmarks' relevance and genericity, we successfully ran performance tests on the TF-IDF and Okapi BM25 weighting schemes, on one hand, and on different relational (Oracle, PostgreSQL) and document-oriented (MongoDB) database implementations, on the other hand. Copyright © 2018, The Authors. All rights reserved.

关键词： Benchmarking