Using Relations on Streams to Solve
نویسنده
چکیده
Abstrac t . We employ a specification and refinement technique based on stream.q to solve the RPC-memory specification problem. Streams are used to represent the communication histories of channels. We distinguish between input and output streams. Each input stream represents the communication history of an input channel; each output stream represents the communication history of an output channel. Specifications are relations between input and output streams. These relations are expressed as logical formulas. Composition corresponds to logical conjunction. We distinguish between time-independent and timedependent specifications. A time-independent specification is based on untimed streams; a time-dependent specification employs timed streams. Timed streams are needed to capture timing constraints and causalities. A specification refines (or alternatively, implements) another specification if any input/output behavior of the former is also an input/output behavior of the latter. This means that refinement corresponds to logical implication.
منابع مشابه
Depth Recovery from Unsynchronized Video Streams
Dynamic depth recovery from unsynchronized video streams is an open problem. In this paper, we propose a novel framework for estimating dense depth information of dynamic scenes using multiple video streams captured from unsynchronized stationary cameras. The main idea is to convert the unsynchronized depth computation problem to the traditional synchronized depth computation problem in which m...
متن کاملAn Abstract Semantics and Concrete Language for Continuous Queries over Streams and Relations
Despite the recent surge of research in query processing over data streams, little attention has been devoted to defining precise semantics for continuous queries over streams. We first present an abstract semantics based on several building blocks: formal definitions for streams and relations, mappings among them, and any relational query language. From these basics we define a precise interpr...
متن کاملMining Frequent Patterns in Uncertain and Relational Data Streams using the Landmark Windows
Todays, in many modern applications, we search for frequent and repeating patterns in the analyzed data sets. In this search, we look for patterns that frequently appear in data set and mark them as frequent patterns to enable users to make decisions based on these discoveries. Most algorithms presented in the context of data stream mining and frequent pattern detection, work either on uncertai...
متن کاملDynamic Depth Recovery from Unsynchronized Video Streams
In this paper, we propose an algorithm for estimating dense depth information of dynamic scenes from multiple video streams captured using unsynchronized stationary cameras. We solve this problem by first imposing two assumptions about the scene motion and the temporal offset between cameras. The motion of a scene is described using a local constant velocity model and the camera temporal offset...
متن کاملThe Health Policy Process in Vietnam: Going Beyond Kingdon’s Multiple Streams Theory; Comment on “Shaping the Health Policy Agenda: The Case of Safe Motherhood Policy in Vietnam”
This commentary reflects upon the article along three broad lines. It reflects on the theoretical choices and omissions, particularly highlighting why it is important to adapt the multiple streams framework (MSF) when applying it in a socio-political context like Vietnam’s. The commentary also reflects upon the analytical threads tackled by Ha et al; for instance, it highlights the opportunitie...
متن کامل