Exploring an unknown environment using team of autonomous mobile robots is an important task in many real-world applications. Many existing map exploration algorithms are based on frontier, which is the boundary betwe...
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Exploring an unknown environment using team of autonomous mobile robots is an important task in many real-world applications. Many existing map exploration algorithms are based on frontier, which is the boundary between unexplored space and known open space. In the context of multiple robots, the main problem of frontier-based algorithm is to choose appropriate target points for the individual robots so that they can efficiently explore the different part of the common area. This paper proposed a novel distributed frontier-based map exploration algorithm using Particle Swarm Optimization model for robot coordination. In this algorithm, the robot keeps moving to the nearby frontier to reduce the size of the unknown region, and is navigated towards frontier far away based on the PSO model after exploring the local area. The exploration is completed when there are no frontier cells on the map. Our algorithm has been implemented and tested both in simulation runs and real world experiment. The result shows that our method has a good scalability and efficiency.
Data analytics involves choosing between many different algorithms and experimenting with possible combinations of those algorithms. Existing approaches however do not support scientists with the laborious tasks of ex...
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Extensive data generated by peers of nodes in wireless sensor networks (WSNs) needs to be analysed and processed in order to extract information that is meaningful to the user. Data processing techniques that achieve ...
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Runtime testing is a common way to detect faults during normal system operation. To achieve a specific diagnostic coverage runtime testing is also used in safety critical, automotive embedded systems. In this paper we...
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Runtime testing is a common way to detect faults during normal system operation. To achieve a specific diagnostic coverage runtime testing is also used in safety critical, automotive embedded systems. In this paper we propose a test architecture to consolidate the hardware resource consumption and timing needs of runtime tests and of application and system tasks in a hard real-time embedded system as applied to the automotive domain. Special emphasis is put to timing requirements of embedded systems with respect to hard real-time and concurrent hardware resource accesses of runtime tests and tasks running on the target system.
The Association for the Advancement of Artificial Intelligence (AAAI) presented the 2010 Fall Symposium Series on November 11-13, 2010. The eight symposia included Cognitive and Metacognitive Educational systems, Comm...
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The Association for the Advancement of Artificial Intelligence (AAAI) presented the 2010 Fall Symposium Series on November 11-13, 2010. The eight symposia included Cognitive and Metacognitive Educational systems, Commonsense Knowledge, Complex Adaptive systems: Resilience, Robustness, and Evolvability, Computational Models of Narrative, Dialog with Robots, Manifold Learning and Its Applications, Proactive Assistant Agents and Quantum Informatics for Cognitive, Social, and Semantic Processes. Cognitive and Metacognitive Educational systems aimed to provide a comprehensive definition of metacognitive educational systems that is inclusive of the theoretical, architectural, and educational aspects of this field. The AAAI Commonsense Knowledge Fall Symposium had the goal of bringing together the diverse elements of this community whose work benefits from or contributes to the representation of general knowledge about the world. One of the specific goals of Proactive symposium was to gather the researchers from various projects in assistant agents to share their wisdom in retrospect.
Energy consumption is becoming a growing concern in data centers. Many energy-conservation techniques have been proposed to address this problem. However, an integrated method is still needed to evaluate energy effici...
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Energy consumption is becoming a growing concern in data centers. Many energy-conservation techniques have been proposed to address this problem. However, an integrated method is still needed to evaluate energy efficiency of storage systems and various power conservation techniques. Extensive measurements of different workloads on storage systems are often very time-consuming and require expensive equipments. We have analyzed changing characteristics such as power and performance of stand-alone disks and RAID arrays, and then defined MIND as a black box power model for RAID arrays. MIND is devised to quantitatively measure the power consumption of redundant disk arrays running different workloads in a variety of execution modes. In MIND, we define five modes (idle, standby, and several types of access) and four actions, to precisely characterize power states and changes of RAID arrays. In addition, we develop corresponding metrics for each mode and action, and then integrate the model and a measurement algorithm into a popular trace tool - blktrace. With these features, we are able to run different IO traces on large-scale storage systems with power conservation techniques. Accurate energy consumption and performance statistics are then collected to evaluate energy efficiency of storage system designs and power conservation techniques. Our experiments running both synthetic and real-world workloads on enterprise RAID arrays show that MIND can estimate power consumptions of disk arrays with an error rate less than 2%.
Monotone prediction problems, in which the target variable is non-decreasing given an increase of the explanatory variables, have became more popular nowadays in many problem settings which fulfill the so-called monot...
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Monotone prediction problems, in which the target variable is non-decreasing given an increase of the explanatory variables, have became more popular nowadays in many problem settings which fulfill the so-called monotonicity constraint, namely, if an object is better in all attributes as another one then it should not be classified lower. Recent approaches to monotone prediction consider linear ordering on attribute domains, thus the meaning of being better in an attribute is limited to having a larger or a lower value in that attribute. However, this limitation restricts the use of recent approaches in cases where middle or marginal values of an attribute are better, what is natural in many real-world scenarios. We present a simple attribute value-transformation approach in this paper. The idea is to map attribute domains to real values where the mapped values express how the given value of an attribute contributes to higher classification of objects. Thus, we are searching for an data-specific approximation of a fuzzy membership function on the domain of each (numerical) attribute. Then, instead of the original attribute values we use their mapped values to mitigate the violation of monotonicity constraints in the data. Our approach is quite simple and is not limited to numerical attributes only. The described approach was tested and evaluated on benchmark datasets from the UCI machine learning repository.
作者:
[Systems Research Institute
Polish Academy of Sciences Warsaw and University of Gdansk Warsaw Poland Systems Research Institute
Polish Academy of Sciences Warsaw and Management Academy Warsaw Poland Software Engineering Department
Faculty of Automatics Computers and Electronics University of Craiova Bvd.Decebal Craiova Romania University of Duisburg-Essen
Institute for Computer Science and Business Information Systems (ICB) Practical Computer Science Data Management Systems and Knowledge Representation Essen Germany
Nowadays, wireless sensor networks are widely used to monitor real time events and answer the ad hoc queries from a certain member node. However, computing and maintaining the information of aggregate queries in event...
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Nowadays, wireless sensor networks are widely used to monitor real time events and answer the ad hoc queries from a certain member node. However, computing and maintaining the information of aggregate queries in event monitoring wireless sensor networks incurs high spatial and temporal overhead for storage and transmission where potentially high volumes of unnecessary data may run through with changing time. Failure of processing that data can lead to unsuccessful event detection which can be very dangerous and costly in real world application. In order to reduce the overhead caused by unnecessary data for aggregate, suppression techniques such as data fusion, data sharing, data prediction, lossless data compression and base station side query rewriting are widely discussed in the WSN research community. In this paper, a technique which makes use of the spatial data relationship of local sensor nodes collaboratively is proposed to rein the detection of composite events with data aggregate. An empirical study is carried out to show the efficiency of the new technique. In addition, the new algorithm is compared to the previous event detection algorithms without spatial data suppression technique to demonstrate the significant performance gains.
Hall devices are magnetic field current sensors based on the Hall effect. A bias current is applied via contacts through the Hall plates which are placed along magnetic field. High frequency components affect the Hall...
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Hall devices are magnetic field current sensors based on the Hall effect. A bias current is applied via contacts through the Hall plates which are placed along magnetic field. High frequency components affect the Hall plates in a non- linear manner, disturbing the uniform biasing current flow. This problem can be alleviated by the development of a flux shaping device. A CAD tool is presented here, which can simulate the behavior of shields with different shape in order to choose the one that may be optimally used.
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