We address the problem of analyzing the reachable set of a polynomial nonlinear continuous system by over-approximating the flow-pipe of its dynamics. the common approach to tackle this problem is to perform a numeric...
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ISBN:
(纸本)9783319961453;9783319961446
We address the problem of analyzing the reachable set of a polynomial nonlinear continuous system by over-approximating the flow-pipe of its dynamics. the common approach to tackle this problem is to perform a numerical integration over a given time horizon based on Taylor expansion and interval arithmetic. However, this method results to be very conservative when there is a large difference in speed between trajectories as time progresses. In this paper, we propose to use combinations of barrier functions, which we call piecewise barrier tube (PBT), to over-approximate flowpipe. the basic idea of PBT is that for each segment of a flowpipe, a coarse box which is big enough to contain the segment is constructed using sampled simulation and then in the box we compute by linear programming a set of barrier functions (called barrier tube or BT for short) which work together to form a tube surrounding the flowpipe. the benefit of using PBT is that (1) BT is independent of time and hence can avoid being stretched and deformed by time;and (2) a small number of BTs can form a tight over-approximation for the flowpipe, which means that the computation required to decide whether the BTs intersect the unsafe set can be reduced significantly. We implemented a prototype called PBTS in C++. Experiments on some benchmark systems show that our approach is effective.
the proceedings contain 14 papers. the special focus in this conference is on Testing Software and Systems. the topics include: Neural networks as artificial specifications;combining model learning and data analysis t...
ISBN:
(纸本)9783319999265
the proceedings contain 14 papers. the special focus in this conference is on Testing Software and Systems. the topics include: Neural networks as artificial specifications;combining model learning and data analysis to generate models of component-based systems;deriving tests with guaranteed fault coverage for finite state machines with timeouts;from ontologies to input models for combinatorial testing;validation of transformation from abstract state machine models to C++ code;security testing for chatbots;JMCTest: Automatically testing inter-method contracts in Java;testing ambient assisted living solutions with simulations;Generating OCL constraints from test case schemas for testing model behavior;Test derivation for SDN-enabled switches: A logic circuit based approach;an energy aware testing framework for smart-spaces;c++11/14 mutation operators based on common fault patterns.
Incorporating a P-type REduced SURface Field (RESURF) layer under an N-type drift region in an nLDMOSFET is a well-known means of improving the trade-off between the on-resistance (Rsp) and off-state breakdown voltage...
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ISBN:
(纸本)9781538629277
Incorporating a P-type REduced SURface Field (RESURF) layer under an N-type drift region in an nLDMOSFET is a well-known means of improving the trade-off between the on-resistance (Rsp) and off-state breakdown voltage (BVoff), as well as reducing hot carrier injection (HCI) degradation. However, the N-type buffer layer under the drain N+ region must be eliminated to maintain a high BVoff in such structures. Generally, HCI degradation occurs near the channel side STI edge at the maximum substrate current (Isubmax). In addition, new HCI degradation occurs in the vicinity of the drain-side STI edge under high gate bias and drain bias conditions because a high electric field is generated near this region. Herein, a new nLDMOSFET in which the STI is divided near the drain-side edge is proposed to suppress this HCI degradation while maintaining the Rsp-Bvoff trade-off.
Despite the many integration tools proposed for mapping between OWL ontologies and the object-oriented paradigm, developers are still reluctant to incorporate ontologies into their code repositories. In this paper we ...
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Despite the many integration tools proposed for mapping between OWL ontologies and the object-oriented paradigm, developers are still reluctant to incorporate ontologies into their code repositories. In this paper we survey existing approaches for OWL-to-OOP mapping trying to identify reasons for this shy adoption of ontologies among conventional software developers. We present a classification of the surveyed approaches and tools based on their technical characteristics and their resulting artifacts. We discuss further potential reasons beyond what have been addressed in the literature before finally providing our own reflection and outlook.
Answer Set programming (ASP) is a powerful modeling formalism for combinatorial problems. However, writing ASP models can be hard. We propose a novel method, called Sketched Answer Set programming (SkASP), aimed at fa...
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ISBN:
(纸本)9781538674499
Answer Set programming (ASP) is a powerful modeling formalism for combinatorial problems. However, writing ASP models can be hard. We propose a novel method, called Sketched Answer Set programming (SkASP), aimed at facilitating this. In SkASP, the user writes partial ASP programs, in which uncertain parts are left open and marked with question marks. In addition, the user provides a number of positive and negative examples of the desired program behaviour. SkASP then synthesises a complete ASP program. this is realized by rewriting the SkASP program into another ASP program, which can then be solved by traditional ASP solvers. We evaluate our approach on 21 well known puzzles and combinatorial problems inspired by Karps 21 NP-complete problems and on publicly available ASP encodings.
We study the reactive synthesis problem for hyperproperties given as formulas of the temporal logic HyperLTL. Hyperproperties generalize trace properties, i.e., sets of traces, to sets of sets of traces. Typical examp...
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ISBN:
(纸本)9783319961453;9783319961446
We study the reactive synthesis problem for hyperproperties given as formulas of the temporal logic HyperLTL. Hyperproperties generalize trace properties, i.e., sets of traces, to sets of sets of traces. Typical examples are information-flow policies like noninterference, which stipulate that no sensitive data must leak into the public domain. Such properties cannot be expressed in standard linear or branching-time temporal logics like LTL, CTL, or CTL*. We show that, while the synthesis problem is undecidable for full HyperLTL, it remains decidable for the there exists*, there exists*for all(1), and the linear for all* fragments. Beyond these fragments, the synthesis problem immediately becomes undecidable. For universal HyperLTL, we present a semi-decision procedure that constructs implementations and counterexamples up to a given bound. We report encouraging experimental results obtained with a prototype implementation on example specifications with hyperproperties like symmetric responses, secrecy, and information-flow.
the design of decentralized energy conversion systems in smart residential microgrids is a challenging optimization problem due to the variety of available generation and storage devices. Common measures to reduce the...
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the design of decentralized energy conversion systems in smart residential microgrids is a challenging optimization problem due to the variety of available generation and storage devices. Common measures to reduce the problem's size and complexity are to reduce modeling accuracy, aggregate multiple loads or change the temporal resolution. However, since these attempts alter the optimization problem and consequently lead to different solutions as intended, this paper presents and analyses a decomposition method for solving the original problem iteratively. the decomposed method is verified by comparison withthe original compact model formulation, proving that both models deviate by less than 1.8%. Both approaches furthermore lead to similar energy systems that are operated similarly, as well. the findings also show that the compact model formulation is only applicable to small- and medium-scale microgrids due to current limitations of computing resources and optimization algorithms, whereas the distributed approach is suitable for even large-scale microgrids. We apply the decomposed method to a large-scale microgrid in order to evaluate economic and ecological benefits of interconnected buildings inside the grid. the results show that with local electricity exchange, costs can be reduced by 4.0% and emissions by even 23.7% for the investigated scenario. (C) 2018 Elsevier Ltd. All rights reserved.
Decentralized (PO) MDPs provide a rigorous framework for sequential multiagent decision making under uncertainty. However, their high computational complexity limits the practical impact. To address scalability and re...
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ISBN:
(纸本)9781577358008
Decentralized (PO) MDPs provide a rigorous framework for sequential multiagent decision making under uncertainty. However, their high computational complexity limits the practical impact. To address scalability and real-world impact, we focus on settings where a large number of agents primarily interact through complex joint-rewards that depend on their entire histories of states and actions. Such history-based rewards encapsulate the notion of events or tasks such that the team reward is given only when the joint-task is completed. Algorithmically, we contribute - 1) A nonlinear programming (NLP) formulation for such event-based planning model;2) A probabilistic inference based approach that scales much better than NLP solvers for a large number of agents;3) A policy gradient based multiagent reinforcement learning approach that scales well even for exponential state-spaces. Our inference and RL-based advances enable us to solve a large real-world multiagent coverage problem modeling schedule coordination of agents in a real urban subway network where other approaches fail to scale.
Teachers face several challenges when presenting fundamental concepts of programming in the classroom. Several tools are introduced to give a visual dimension to support the learning process. they rely on code blocks,...
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Teachers face several challenges when presenting fundamental concepts of programming in the classroom. Several tools are introduced to give a visual dimension to support the learning process. they rely on code blocks, easily manipulated in a plug and play fashion, to build a program. these block-based tools intend to familiarize students withprogramminglogic, before diving into text-based programming languages such as Java, Python, etc. However; when transitioning from block-based to text-based programming, students often encounter a gap in their learning. the student may not be able to apply block-based foundations in a text-based environment. To bridge the gap between both environments, we developed a hybrid-based learning approach. We found that on average a hybrid-based approach increases the students understanding of programming foundations, memorization, and ease of transition by more than 30% when compared to a block-based to text-based learning approach. Finally, we provide the community with an open source, hybrid-based learning tool that can be used by students when learning programming concepts or for future studies.
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