Bounded model checking (BMC) has successfully been used for many practical program verification problems, but concurrency still poses a challenge. Here we describe a new approach to BMC of sequentially consistent C pr...
详细信息
ISBN:
(纸本)9783319088679;9783319088662
Bounded model checking (BMC) has successfully been used for many practical program verification problems, but concurrency still poses a challenge. Here we describe a new approach to BMC of sequentially consistent C programs using POSIX threads. Our approach first translates a multi-threaded C program into a nondeterministic sequential C program that preserves reachability for all round-robin schedules with a given bound on the number of rounds. It then re-uses existing high-performance BMC tools as backends for the sequential verification problem. Our translation is carefully designed to introduce very small memory overheads and very few sources of nondeterminism, so that it produces tight SAT/SMT formulae, and is thus very effective in practice: our prototype won the concurrency category of SV-COMP14. It solved all verification tasks successfully and was 30x faster than the best tool with native concurrency handling.
this paper considers Underwater Sensor Networks (UWSNs) with unanchored nodes that can move freely with water currents. thus, node locations at any instant can only be specified probabilistically. When connectivity am...
详细信息
this paper considers Underwater Sensor Networks (UWSNs) with unanchored nodes that can move freely with water currents. thus, node locations at any instant can only be specified probabilistically. When connectivity among some of the sensor nodes is required to perform a given function, the problem of estimating the likelihood that the network achieves such connectivity arises. Our work here formulates a parameterized probabilistic connectivity problem that serves this purpose when the network contains both sensor nodes and relay nodes. We show an exact dynamic programming algorithm for solving the problem on networks with tree-like structure; the algorithm yields lower bounds on the solution of the problem on any arbitrary network. the obtained simulation results investigate the gap between our obtained lower bounds and exact solutions on small networks, as well as the usefulness of our method in analyzing the effect of adding relay nodes to the network.
We report on the development of a tunable antenna coupled intersubband terahertz (TACIT) detector based on GaAs/AlGaAs two dimensional electron gas. A successful device design and micro-fabrication process have been d...
详细信息
We report on the development of a tunable antenna coupled intersubband terahertz (TACIT) detector based on GaAs/AlGaAs two dimensional electron gas. A successful device design and micro-fabrication process have been developed which maintain the high mobility (1.1×10 6 cm 2 /V-s at 10K) of a 2DEG channel in the presence of a highly conducting backgate. Gate voltage-controlled device resistance and direct thz sensing has been observed. the goal is to operate as a nearly quantum noise limited heterodyne sensor suitable for passively-cooled space platforms.
We present an approach for two-port on-wafer calibration to establish the test reference planes within the substrate of the device under test for the WR3 (220-325 GHz) and WR5 (140-220 GHz) frequency bands. On-wafer c...
详细信息
We present an approach for two-port on-wafer calibration to establish the test reference planes within the substrate of the device under test for the WR3 (220-325 GHz) and WR5 (140-220 GHz) frequency bands. On-wafer calibration is useful for characterizing elements such as transistors for modeling or for the confirmation of circuit models. there are numerous publications for on-wafer calibrations, this discussion differs in that we will present our on-wafer calibration approach with comparison of measurements and simulations of passive structures and that of a transistor model constructed from lower frequency measurements. We discuss practical considerations for the approach we have utilized for high frequency characterization.
We report on terahertz detection experiments at 240 GHz using carbon-nanotube field-effect transistors with a single semiconducting single-walled tube as the transistor's channel. From DC channel resistance measur...
详细信息
We report on terahertz detection experiments at 240 GHz using carbon-nanotube field-effect transistors with a single semiconducting single-walled tube as the transistor's channel. From DC channel resistance measurements, the voltage response is predicted theoretically from the dc transconductance of the devices. Rectification is shown for an electronically applied 2-MHz signal and for free-space illumination at 240 GHz. the measured voltage responses compare well withthe theory, however, at 240 GHz an additional gate-bias-dependent contribution to the rectified signal is observed for higher gate voltages.
We report on room-temperature plasmonic detection of the thermal emission from a black body in the terahertz and mid-infrared domains by dual-grating-gate InAlAs/InGaAs/InP high electron mobility transistors (HEMTs). ...
详细信息
We report on room-temperature plasmonic detection of the thermal emission from a black body in the terahertz and mid-infrared domains by dual-grating-gate InAlAs/InGaAs/InP high electron mobility transistors (HEMTs). In such detectors, the asymmetric grating gate of a large area acts as an effective antenna that improves the performance in the two spectral domains.
We present a system that computes for a query that may be incomplete, complete approximations from above and from below. We assume a setting where queries are posed over a partially complete database, that is, a datab...
详细信息
We present a system that computes for a query that may be incomplete, complete approximations from above and from below. We assume a setting where queries are posed over a partially complete database, that is, a database that is generally incomplete, but is known to contain complete information about specific aspects of its application domain. Which parts are complete, is described by a set of so-called table-completeness statements. Previous work led to a theoretical framework and an implementation that allowed one to determine whether in such a scenario a given conjunctive query is guaranteed to return a complete set of answers or not. Withthe present demonstrator we show how to reformulate the original query in such a way that answers are guaranteed to be complete. If there exists a more general complete query, there is a unique most specific one, which we find. If there exists a more specific complete query, there may even be infinitely many. In this case, we find the least specific specializations whose size is bounded by a threshold provided by the user. Generalizations are computed by a fixpoint iteration, employing an answer set programming engine. Specializations are found leveraging unification from logicprogramming.
In this paper we present a model transformation language based on logicprogramming. the language, called PTL (Prolog based Transformation Language), can be considered as a hybrid language in which ATL-style rules are...
详细信息
ISBN:
(纸本)9783642358432
In this paper we present a model transformation language based on logicprogramming. the language, called PTL (Prolog based Transformation Language), can be considered as a hybrid language in which ATL-style rules are combined withlogic rules for defining transformations. the proposal has been implemented so that a Prolog program is automatically obtained from a PTL program. We have equipped our language with debugging and tracing capabilities which help developers to detect programming errors in PTL rules.
the following is a brief introduction to the the problems of time and control as they relate to real-time computer music systems. A new C language framework for realizing computer music is presented as a means of addr...
详细信息
ISBN:
(纸本)9780984527427
the following is a brief introduction to the the problems of time and control as they relate to real-time computer music systems. A new C language framework for realizing computer music is presented as a means of addressing these issues and programming computer music generally. the framework is called 'timelab' and it is intended for use both on PCs as well as embedded systems.
暂无评论