Digital-Twin technology can be considered as a giant step toward Industry 4.0. Automated product life-cycle development that can be achieved by digital-twin and AI solutions is of a high concern recently both in acade...
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The accurate environment perception of automobiles and UAVs (Unmanned Ariel Vehicles) relies on the precision of onboard sensors, which require reliable in-field calibration. This paper introduces a novel approach for...
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As millimeter-wave (mmWave) signals suffer from high path loss and blocking, passive metasurface reflectors that can be fabricated with conventional PCB manufacturing become a promising cost-effective candidate for en...
As millimeter-wave (mmWave) signals suffer from high path loss and blocking, passive metasurface reflectors that can be fabricated with conventional PCB manufacturing become a promising cost-effective candidate for enhancing mmWave mobile service coverage. In this work, we show how PCB fabrication geometrical precision affects the performance of passive reflectors that are used in 5G and beyond mmWave networks. With the broad beamwidth of PCB-based metasurfaces, the dimension tolerance of PCB manufacturing can be traded off between cost benefits and key communications performance. From our numerical results based on full-wave simulations, the received power at the design anomalous angle is not significantly affected by the geometrical precision while high errors can cause higher interference at specular and mirror angles. However, the fabrication error in unit cell shape rotation does not influence the received power at the design anomalous, specular and mirror angles.
This paper proposes the design of a phase-gradient reflecting metasurface (MTS) to improve 5G mmWave coverage, following the principle of perfect anomalous reflection. The reflective responses of a simple structure wi...
This paper proposes the design of a phase-gradient reflecting metasurface (MTS) to improve 5G mmWave coverage, following the principle of perfect anomalous reflection. The reflective responses of a simple structure with cross-shaped resonators have been investigated. The results from a full wave simulation show that the proposed MTS with a surface area of 23×23 cm 2 can anomalously reflect a linear dual-polarized plane wave at 25.8 GHz from an incident angle of 30° to a reflection angle of 54° with a more than 10 dB radiation power ratio between the main reflected beam and its sidelobe at a specular reflecting direction.
Recent innovative Artificial Intelligence (AI) solutions accelerate digital transformations in different fields. It is important to highlight and explore this innovative AI service in different domains so that digital...
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The recent increment of population in the urban areas requires well-operated and well-managed cities with lots of automation in various aspects of everyday life. The backbone of this smart city is the Internet-of-Thin...
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In modern industrial settings with small batch sizes it should be easy to set up a robot system for a new task. Strategies exist, e.g. the use of skills, but when it comes to handling forces and torques, these systems...
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ISBN:
(纸本)9781665481106
In modern industrial settings with small batch sizes it should be easy to set up a robot system for a new task. Strategies exist, e.g. the use of skills, but when it comes to handling forces and torques, these systems often fall short. We introduce an approach that provides a combination of task-level planning with targeted learning of scenario-specific parameters for skill-based systems. We propose the following pipeline: the user provides a task goal in the planning language PDDL, then a plan (i.e., a sequence of skills) is generated and the learnable parameters of the skills are automatically identified, and, finally, an operator chooses reward functions and parameters for the learning process. Two aspects of our methodology are critical: (a) learning is tightly integrated with a knowledge framework to support symbolic planning and to provide priors for learning, (b) using multi-objective optimization. This can help to balance key performance indicators (KPIs) such as safety and task performance since they can often affect each other. We adopt a multi-objective Bayesian optimization approach and learn entirely in simulation. We demonstrate the efficacy and versatility of our approach by learning skill parameters for two different contact-rich tasks. We show their successful execution on a real 7-DOF KUKA-iiwa manipulator and outperform the manual parameterization by human robot operators.
Matching problems under preferences gained significant attention not just in mathematical sciences, but in other fields too since the paper published by Gale and Shapley in 1962-ben on the college admission being mode...
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Matching problems under preferences gained significant attention not just in mathematical sciences, but in other fields too since the paper published by Gale and Shapley in 1962-ben on the college admission being modelled as a matching problem with preferences, and Al Roth's work on matching problems in practice, such as modelling kidney exchanges as matching markets. For their work on matching markets, Roth and Shapley received the 2012 Nobel Memorial Prize in Economics. Today, this interdisciplinary field extended to other parts of mathematics, for example, stability of flows is examined, and focuses on the real-life application of this field. One such application is financial clearing, or portfolio compression. Market participants (banks, organizations, companies, financial agents) sign contracts, creating liabilities between each other, which increases the systemic risk. Large, dense markets commonly can be compressed by reducing obligations without lowering the net notional of each participant (an example is if liabilities make a cycle between agents, then it is possible to reduce each of them altogether without any net notional changing), and our target is to eliminate as much excess notional as possible in practice (excess is defined as the difference between gross and net notional). A limiting factor which may reduce the effectiveness of the compression can be the preferences and priorities of compression participants, who may individually define conditions for the compression, which must be considered when designing the clearing process, otherwise a participant may bail out, resulting in the designed clearing process to be impossible to execute. These markets can be well-represented with edge-weighted graphs. In this paper, I examine cases when preferences and conditions of participants on behalf of clearing are given, e.g., in what order would they pay back their liabilities (a key factor can be rate of interest) and I show a clearing algorithm for these p
We discover a first-order phase transition in the canonical ensemble of random unlabeled networks with a prescribed average number of links. The transition is caused by the nonconcavity of microcanonical entropy. Abov...
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We discover a first-order phase transition in the canonical ensemble of random unlabeled networks with a prescribed average number of links. The transition is caused by the nonconcavity of microcanonical entropy. Above the critical point coinciding with the graph symmetry phase transition, the canonical and microcanonical ensembles are equivalent and have a well-behaved thermodynamic limit. Below the critical point, the ensemble equivalence is broken, and the canonical ensemble is a mixture of phases: empty networks and networks with average degrees diverging logarithmically with the network size. As a consequence, networks with bounded average degrees do not survive in the thermodynamic limit, decaying into the empty phase. The celebrated percolation transition in labeled networks is thus absent in unlabeled networks. In view of these differences between labeled and unlabeled ensembles, the question of which one should be used as a null model of different real-world networks cannot be ignored.
Designing lightweight yet stiff structures that can withstand vibrations is a crucial task in structural optimization. Here, we present a novel framework for truss topology optimization under undamped harmonic oscilla...
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