Search results for "Hard"
showing 10 items of 2294 documents
A Lightweight Network Discovery Algorithm for Resource-constrained IoT Devices
2019
Although quite simple, existing protocols for the IoT suffer from the inflexibility of centralized infrastructures and require several configuration stages. The implementation of these protocols is often prohibitive on resource-constrained devices. In this work, we propose a distributed lightweight implementation of network discovery for simple IoT devices. Our approach is based on the exchange of symbolic executable code among nodes. Based on this abstraction, we propose an algorithm that makes even IoT resource-constrained nodes able to construct the network topology graph incrementally and without any a priori information about device positioning and presence. The minimal set of executab…
Local maximal operators on fractional Sobolev spaces
2016
In this note we establish the boundedness properties of local maximal operators MG on the fractional Sobolev spaces Ws;p(G) whenever G is an open set in Rn, 0 < s < 1 and 1 < p < 1. As an application, we characterize the fractional (s;p)-Hardy inequality on a bounded open set by a Maz'ya-type testing condition localized to Whitney cubes. pq(G) whenever G is an open set in R n , 0 < s < 1 and 1 < p;q <1. Our main focus lies in the mapping properties of MG on a fractional Sobolev space W s;p (G) with 0 < s < 1 and 1 < p < 1, see Section 2 for the denition or (3) for a survey of this space. The intrinsically dened function space W s;p (G) on a given domain G coincides with the trace space F s …
Capacity-based calculation of passenger car equivalents using traffic simulation at double-lane roundabouts
2018
Abstract Calculation of passenger car equivalents for heavy vehicles represents the starting point for the operational analysis of road facilities and other traffic management applications. This paper introduces a criterion to find the passenger car equivalents that reflect traffic conditions at double-lane roundabouts, where the capacity is typically estimated for each entry lane. Based on the equivalence defined by the proportion of capacity used by vehicles of different classes, the criterion implies a comparison between the capacity that would occur with a traffic demand of passenger cars only and the capacity reached beginning from a demand with a certain percentage of heavy vehicles. …
A Compact SPICE Model for Organic TFTs and Applications to Logic Circuit Design
2016
This work introduces a compact DC model developed for organic thin film transistors (OTFTs) and its SPICE implementation. The model relies on a modified version of the gradual channel approximation that takes into account the contact effects, occurring at nonohmic metal/organic semiconductor junctions, modeling them as reverse biased Schottky diodes. The model also comprises channel length modulation and scalability of drain current with respect to channel length. To show the suitability of the model, we used it to design an inverter and a ring oscillator circuit. Furthermore, an experimental validation of the OTFTs has been done at the level of the single device as well as with a discrete-…
On the satisfiability problem for fragments of two-variable logic with one transitive relation
2019
Abstract We study the satisfiability problem for two-variable first-order logic over structures with one transitive relation. We show that the problem is decidable in 2-NExpTime for the fragment consisting of formulas where existential quantifiers are guarded by transitive atoms. As this fragment enjoys neither the finite model property nor the tree model property, to show decidability we introduce a novel model construction technique based on the infinite Ramsey theorem. We also point out why the technique is not sufficient to obtain decidability for the full two-variable logic with one transitive relation; hence, contrary to our previous claim, [FO$^2$ with one transitive relation is deci…
Inductive Power Transfer for 100W battery charging
2013
Today, Inductive Power Transfer (IPT) is widely investigated to provide wireless battery charge. Potential applications range from a few Watts of handheld devices to kWatts of automotive applications. Despite of comfort and safety options, wireless charging features relatively poor power conversion efficiency. In the literature, several solutions are proposed addressing efficiency related issues. In this paper, a 100W wireless charging station for electric bikes which improves the power conversion efficiency is proposed. The magnetic structure design is analyzed thoroughly as well as the proposed power electronics system architectures of both the power transmitter and power receiver. The ef…
On solving separable block tridiagonal linear systems using a GPU implementation of radix-4 PSCR method
2018
Partial solution variant of the cyclic reduction (PSCR) method is a direct solver that can be applied to certain types of separable block tridiagonal linear systems. Such linear systems arise, e.g., from the Poisson and the Helmholtz equations discretized with bilinear finite-elements. Furthermore, the separability of the linear system entails that the discretization domain has to be rectangular and the discretization mesh orthogonal. A generalized graphics processing unit (GPU) implementation of the PSCR method is presented. The numerical results indicate up to 24-fold speedups when compared to an equivalent CPU implementation that utilizes a single CPU core. Attained floating point perfor…
A Cost-Effective Approach to Hardware-in-the-Loop Simulation
2012
This paper presents an approach for developing cost effective hardware-in-the-loop (HIL) simulation platforms for the use in controller software test and development. The approach is aimed at the many smaller manufacturers of e.g. mobile hydraulic machinery, which often do not have very advanced testing facilities at their disposal. A case study is presented where a HIL simulation platform is developed for the controller of a truck mounted loader crane. The total expenses in hardware and software is less than 10.000$.
From UML Specification into FPGA Implementation
2014
In the paper a method of using the Unified Modeling Language for specification of digital systems, especially logic controllers, is presented. The proposed method is based mainly on the UML state machine di- agrams and uses Hierarchical Concurrent Finite State Machines (HCFSMs) as a temporary model. The paper shows a way to transform the UML diagrams, expressed in XML language, to the form that is acceptable by reconfigurable FPGAs (Field Programmable Gate Ar- rays). The UML specification is used to generate an eective program in Hardware Description Languages (HDLs), especially Verilog.
From UML State Machine Diagram into FPGA Implementation
2013
Abstract In the paper a method of using the Unified Modeling Language diagrams for specification of digital systems, especially logic controllers, is presented. The proposed method is based mainly on the UML state machine diagrams and uses Hierarchical Concurrent Finite State Machines (HCFSMs) as a temporary model. The paper shows a way to transform the UML diagrams to the form that is acceptable by reconfigurable FPGAs (Field Programmable Gate Arrays). The UML specification is used to generate an effective program in Hardware Description Languages (HDLs), especially Verilog.