Event notification services are used in various applications such as digital libraries, stock tickers, traffic control, or facility management. However to our knowledge, a common semantics of events in event notification services has not been defined so far. We propose a parameterized event algebra which describes the semantics of composite events for event notification systems. The parameters ser...... hiện toàn bộ
#Algebra #Logistics #Temperature sensors #Software libraries #Filtering #Database systems #Clocks
Chúng tôi giới thiệu một logic thời gian để lý luận về các ứng dụng toàn cầu. Trước tiên, chúng tôi định nghĩa một logic mô-đun cho địa phương tính, nhúng các lý thuyết địa phương của mỗi thành phần vào một lý thuyết về các trạng thái phân tán của hệ thống. Chúng tôi cung cấp cho logic một hệ thống tiên đề đầy đủ và chuyên sâu. Sau đó, chúng tôi mở rộng logic với một toán tử thời gian. Đóng góp củ...... hiện toàn bộ
#Logic #DSL #Đồng hồ #Giao tiếp bất đồng bộ #Ngôn ngữ đặc tả #Điện toán đồng thời #Điện toán phân tán #Trì hoãn #Điện toán phổ biến #Thư viện thời gian chạy
We evaluate a model for temporal data utilizing the benefits of object-relational database systems (ORDBS). In particular we show how attribute timestamping can be efficiently implemented in state-of-the-art ORDBS. The attribute timestamping concept is based on introducing user-specific types for temporal versions of datatypes. Moreover on the physical level we make use of user-defined index struc...... hiện toàn bộ
#Object oriented modeling #Indexing #Spatial indexes #Relational databases #Information systems #Database systems #Data models #Spatial databases #Size measurement
We show the expressiveness provided by a labelled point-based metric model for specifying and reasoning about complex disjunctive temporal constraints. The model allows us to manage disjunctive assertions, conjunctive and hypothetical queries, and one-to-many constraints. Additionally, it becomes an adequate support for reasoning on costs associated to constraints.
We propose a logical approach to represent and reason about different time granularities. We identify a time granularity as a discrete infinite sequence of time points properly labelled with proposition symbols marking the starting and ending points of the corresponding granules, and we intensively model sets of granularities with linear time logic formulas. Some real-world granularities are provi...... hiện toàn bộ
Representing and reasoning with both temporal constraints between classes of events (e.g., between the types of actions needed to achieve a goal) and temporal constraints between instances of events (e.g., between the specific actions being executed) is a ubiquitous task in many areas of computer science, such as planning, workflow, guidelines and protocol management. The temporal constraints betw...... hiện toàn bộ
S. Bauer, I. Hodkinson, F. Wolter, M. Zakharyaschev
We prove decidability of 'non local' propositional CTL*, where truth values of atoms may depend on the branch of evaluation. This result is then used to show decidability of the 'weak' one-variable fragment of first-order (local) CTL*, in which all temporal operators and path quantifiers except 'tomorrow' are applicable only to sentences. Various spatio-temporal logics based on combinations of CTL...... hiện toàn bộ
Temporal joins are important but very costly operations. While a temporal join can involve the whole time (and/or key) domain, we consider the more general case where the join is defined by some time-key rectangle from the whole space (i.e., when the user is interested in joining portions of the-usually large-temporal data). In the most restrictive join, objects (within this rectangle) are joined ...... hiện toàn bộ
Events employed in natural language semantics are characterized in terms of regular languages, each string in which can be regarded as a motion picture. The relevant finite automata then amount to movie cameras/projectors, or more formally, to finite Kripke structures with partial valuations. The usual regular constructs (concatenation, choice, etc) are supplemented with superposition of strings/a...... hiện toàn bộ
The disjunctive fuzzy temporal constraint network (DFTCN) model is a framework that allows reasoning with fuzzy qualitative and quantitative complex temporal constraints. However, its general complexity is exponential. In this work, we review methods that can reduce this complexity, based on graph topology and preprocessing. The final goal is to integrate all these methods into a general tool for ...... hiện toàn bộ