Ontology of anomalous processes diagnosis

The diagnosis is complex in domains where processes occur over time inside systems or objects, changing and affecting other processes and characteristics. A large number of knowledge‐based systems have been developed to increase the efficiency of the diagnostic process. But the models of knowledge of such systems do not simultaneously take into account all types of temporal relationships: changes in the values of attributes over time, taking into account the time intervals that have passed from the moments when the process began to develop and external influences, and so forth. The article considers the universal ontology of knowledge about the diagnosis of processes in various domains as a generalization and the result of many years of experience of the authors in the creation of intelligent systems for the diagnosis of processes. The ontology allows us to formalize anomalies as developing internal processes that are not inherent in a normally functioning system. On its basis (in its terms) knowledge bases and software components for decision support systems are constructed. In the case of a need for a domain‐oriented ontology, it will only be necessary to redefine some concepts and relations which are features of specific domains.     

A new spatio-temporal method for event detection and personalized retrieval of sports video

In this paper, a new spatio-temporal method for adaptively detecting events based on Allen temporal algebra and external information support is presented. The temporal information is captured by presenting events as the temporal sequences using a lexicon of non-ambiguous temporal patterns. These sequences are then exploited to mine undiscovered sequences with external text information supports by using class associate rules mining technique. By modeling each pattern with linguistic part and perceptual part those work independently and connect together via transformer, it is easy to deploy this method to any new domain (e.g baseball, basketball, tennis, etc.) with a few changes in perceptual part and transformer. Thus the proposed method not only can work well in unwell structured environments but also can be able to adapt itself to new domains without the need (or with a few modification) for external re-programming, re-configuring and re-adjusting. Results of automatic event detection progress are tailored to personalized retrieval via click-and-see style using either conceptual or conceptual-visual query scheme. Experimental results carried on more than 30 hours of soccer video corpus captured at different broadcasters and conditions as well as compared with well-known related methods, demonstrated the efficiency, effectiveness, and robustness of the proposed method in both offline and online processes.     

A layered semantics for a parallel object-oriented language

We develop a denotational semantics for POOL, a parallel object-oriented programming language. The main contribution of this semantics is an accurate mathematical model of the most important concept in object-oriented programming: the object. This is achieved by structuring the semantics in layers working at three different levels: for statements, objects and programs. For each of these levels we define a specialized mathematical domain of processes, which we use to assign a meaning to each language construct. This is done in the mathematical framework of complete metric spaces. We also define operators that translate between these domains. At the program level we give a precise definition of the observable input/output behaviour of a particular program, which could be used at a later stage to decide the issue of full abstractness. We illustrate our semantic techniques by first applying them to a toy language similar to CSP.This paper describes work done in ESPRIT Basic Research Action 3020,Integration.     

Group planning with time constraints

Embedding planning systems in real-world domains has led to the necessity of Distributed Continual Planning (DCP) systems where planning activities are distributed across multiple agents and plan generation may occur concurrently with plan execution. A key challenge in DCP systems is how to coordinate activities for a group of planning agents. This problem is compounded when these agents are situated in a real-world dynamic domain where the agents often encounter differing, incomplete, and possibly inconsistent views of their environment. To date, DCP systems have only focused on cases where agents’ behavior is designed to optimize a global plan. In contrast, this paper presents a temporal reasoning mechanism for self-interested planning agents. To do so, we model agents’ behavior based on the Belief-Desire-Intention (BDI) theoretical model of cooperation, while modeling dynamic joint plans with group time constraints through creating hierarchical abstraction plans integrated with temporal constraints network. The contribution of this paper is threefold: (i) the BDI model specifies a behavior for self interested agents working in a group, permitting an individual agent to schedule its activities in an autonomous fashion, while taking into consideration temporal constraints of its group members; (ii) abstract plans allow the group to plan a joint action without explicitly describing all possible states in advance, making it possible to reduce the number of states which need to be considered in a BDI-based approach; and (iii) a temporal constraints network enables each agent to reason by itself about the best time for scheduling activities, making it possible to reduce coordination messages among a group. The mechanism ensures temporal consistency of a cooperative plan, enables the interleaving of planning and execution at both individual and group levels. We report on how the mechanism was implemented within a commercial training and simulation application, and present empirical evidence of its effectiveness in real-life scenarios and in reducing communication to coordinate group members’ activities.     

Utilizing Event-B for domain engineering: a critical analysis

This paper presents our experience of modeling land transportation domain in the formal framework of Event-B. Well-specified requirements are crucial for good software design; they depend on the understanding of the domain. Thus, domain engineering becomes an essential activity. The possibility to have a formal model of a domain, consistent with the use of formal methods for developing critical software working within it, is an important issue. Safety-critical domains, like transportation, exhibit interesting features, such as high levels of nondeterminism, complex interactions, stringent safety properties, and multifaceted timing attributes. The formal representation of these features is a challenging task. We explore the possibility of utilizing Event-B as a domain engineering tool. We discuss the problems we faced during this exercise and how we tackled them. Special attention is devoted to the issue of the validation of the model, in particular with a technique based on the animation of specifications. Event-B is mature enough to be an effective tool to model domains except in some areas, temporal properties mainly, where more work is still needed.     

A Qualitative Model for Time Granularity

This paper addresses the problem of granularity in temporal representation in the context of text analysis. In contrast with other fields where granularity levels are essentially quantitative, in natural language the different levels are not always precisely defined and granularity is of a more subtle and qualitative nature. A model is proposed for representing such phenomena, based on time units and time units intervals. Time units represent chunks of time which are considered indivisible at a given granularity level, but which may be refined and contain other time units or intervals at a higher granularity level. The structure of the set of time units and intervals is studied and a relation algebra is defined which extends the traditional Allen's Point or Interval Algebra. Weak and strong representations of this algebra are proposed. We claim that such representations, called grained temporal structures, are adequate for coping with dynamic qualitative changes of granularity. A logic with restricted quantifiers is proposed for formalizing temporal knowledge and examples are discussed which show the relevance of the model for natural language analysis.     

Improving performance reliability in surgical systems

Health care has evolved rapidly to meet the medical demands of society, but not to meet the demands of consistent operational safety. In other high risk domains in which the consequences of systems failure are unacceptable, organisational and operational work systems have been developed to deliver consistent, high-quality, failure-free performance. In this paper we review contributions to a special issue of Cognition, Technology and Work on ‘Enhancing Surgical Systems’. We consider their implications for improving the reliability of care processes in light of theoretical developments in the area of high-reliability organisations and resilience engineering. Health care must move from reactive safety cultures to be more proactively resilient to the continual threats posed by complexity in clinical care processes and the multi-professional hospital environment. Our analysis emphasises the importance of team working for reliable operational performance. A schematic framework to illustrate how safety interventions in surgery might cohere within an organisational strategy for achieving high-reliability is proposed. The implications for continuous quality improvement and effective regulation of system safety over differing time scales and organisational levels are discussed.     

Approaching institutional contexts: systemic versus dialogic research in CSCL

The research literature in CSCL has rarely addressed the question of how institutional contexts contribute to constituting the meanings and functions of CSCL applications. The argument that we develop here concerns how the institutional context impacts the use of CSCL applications and how this impact should be conceptualized. In order to structure to our argument, we introduce a distinction between systemic and dialogic approaches to CSCL research. We develop our argument by working through a selection of relevant studies belonging to the two perspectives, and conclude that not enough attention has been given to the emergent characteristics of activities where CSCL tools have been introduced. This is particularly the case in studies belonging to a systemic approach. Our basic argument is that a dialogic stance can provide important insights into how institutional practices shape the meanings and functions of CSCL tools. A dialogic perspective provides opportunities for making sense of learning and knowledge construction at different levels of activity, while at the same time retaining sensitivity to the mutually constitutive relationship between levels.     

DAISY: a decision support design methodology for complex,experience-centered domains

Users at different levels of domain experience have very different needs. For example, a system designed to assist domain novices may frustrate experts and vice-versa. This is one of several challenges specific to building decision support systems for experience-centered domains. A second challenge in working with complex experience-centered domains is that it is hard for non-experts to understand the domain in order to model it. In this paper we present DAISY, the design aid for intelligent support systems. It is a software design methodology for constructing decision support systems in complex, experience-based domains. DAISY address the specialized challenges of these domains by augmenting existing cognitive engineering methodologies. In particular, DAISY provides a method for identifying the specialized needs of users within a specific range of domain experience. Thus, it can help software designers to understand "What does the domain expert need?" or "What does a trained novice need?" To help system designers manage the complexity of modeling unfamiliar experience-centered domains, it provides a tool called a time/activity matrix. To illustrate each of DAISY's steps, we used the development of a decision support system called Fox. Fox assists expert military planners by rapidly generating alternative plans. This is a cognitively difficult, time critical task with life and death consequences     

Domain Monotonicity and the Performance of Local Solutions Strategies for CDPS-based Distributed Sensor Interpretation and Distributed Diagnosis

The growth in computer networks has created the potential to harness a great deal of computing power, but new models of distributed computing are often required. Cooperative distributed problem solving (CDPS) is the subfield of multi-agent systems (MAS) that is concerned with how large-scale problems can be solved using a network of intelligent agents working together. Building CDPS systems for real-world applications is still very difficult, however, in large part because the effects that domain and strategy characteristics have on the performance of CDPS systems are not well understood. This paper reports on the first results from a new simulation-based analysis system that has been created to study the performance of CDPS-based distributed sensor interpretation (DSI) and distributed diagnosis (DD). To demonstrate the kind of results that can be obtained, we have investigated how the monotonicity of a domain affects the performance of a potentially very efficient class of strategies for CDPS-based DSI/DD. Local solutions strategies attempt to limit communications among the agents by focusing on using the agents' local solutions to produce global solutions. While these strategies have been described as being important for effective CDPS-based DSI/DD, they need not perform well if a domain is nonmonotonic. We had previously suggested that the reason they have performed well in several research systems was that many DSI/DD domains are what we termed nearly monotonic. In this paper, we will provide quantitative results that relate the performance of local solutions strategies to the monotonicity of a domain. The experiments confirm that domain monotonicity can be important to consider, but they also show that it is possible for these strategies to be effective even when domains are relatively nonmonotonic. What is required is that the agents receive a significant fraction of the data that is relevant to their subproblems. This has important implications for the design of DSI/DD systems using local solutions strategies. In addition, while the work indicates that many DSI/DD domains are likely to be nearly monotonic according to our original definitions, it also shows that these measures are not as predictive of performance as other measures we define. This means that near monotonicity alone does not explain why local solutions strategies have performed well in previous systems. Instead, a likely explanation is that these systems typically involved only a small number of agents.     

A microworld approach to the formalization of musical knowledge

This paper is about the importance of applying computational modeling and artificial intelligence techniques to music cognition and computer music research. The construction of microworlds as a methodology plays a key role in the different stages of this research. Several uses of microworlds are described. Microworlds have been criticized in the domains of artificial intelligence and the cognitive sciences, but this critique has to be seen in its proper context (i.e. in modeling of human intelligence, not as a methodology). It is shown that the microworld approach is still an important methodology in music cognition and computer music research, and a promising strategy in the design of a general representation formalism of musical knowledge.Henkjan Honing is research fellow at the University of Amsterdam, where he is doing research on the formalization of musical knowledge concentrating on time and temporal structure. With Peter Desain he wrote the bookMusic, Mind and Machine: Studies in Computer Music, Music Cognition and Artificial Intelligence.     

多域环境下工作流访问控制时序策略组合研究

多域环境下工作流访问控制策略往往表现为异构策略的时序组合,其基本需求是使访问主体在一定的时间段或者时间周期内具有对客体的访问权限.XACML在描述策略组合时,并没有体现异构策略组合时态约束.根据GTRBAC提出的时态约束种类,定义了相关时态策略并进行了图解说明;并对XACML进行了扩展,引入了相应的时态约束元素.最后,...     

Dense Time Logic Programming

In this paper, we describe a dense temporal logic programming (DTLP) framework based on infinite binary trees calledomega trees. We then look at an important subset of omega trees calledordinal treesthat represent only meaningful dense time models. Ordinal trees have the properties ofstabilityandrecurrence, which allow them to be represented finitely. The finite representations calledordinal structurescan be used as temporal data structures and its nodes can be labelled with formulae, giving us the basis for modeling temporally located information. In this paper, we label ordinal structure nodes with Prolog clauses to gettemporal horn clausesthat represent temporal facts, rules and queries. Temporal resolution tries to prove temporal queries from a set of temporal facts and rules using a process calledaligningwhich provides the counterpart of the conventional unification algorithm. Aligning restructures ordinal trees to facilitate the transfer of temporal information between them. We present theoretical results to show that aligning is computable, and that the procedures for aligning and resolution are correct.     

Modelling and managing disjunctions in scheduling problems

In this paper is presented a method for modelling and managing various constraints encountered in task scheduling problems. The approach aims at characterizing feasible schedules through the analysis of the set of constraints and their interaction, regardless of any optimization criteria. This analysis is achieved by a constraint propagation process on a constraint graph and produces both restricted domains for the decision variables and an updated formulation of the initial constraints. The graphs usually used to model temporal constraints seem to be limited because they only allow the representation of strict precedence relations between two tasks. In order to model a larger variety of temporal constraints, particularly any constraint that connects two events (start- or finish- time of a task), a model called a time-bound-on-node (TBON) graph is proposed in which each task is featured by two nodes. Then it becomes possible to handle constraints on task durations, due for example to flexibilities in resource utilization. This kind of graph is not new and has already been investigated in related works on project planning and Constraint Satisfaction Problems. But its processing and interpretation deserved to he developed, particularly for the present purpose, which is the search for the necessary conditions of feasibility. With respect to conjunctive temporal constraints, the analysis is achieved with a polynomial algorithm based on the longest path search on a conjunctive TBON graph, yielding the necessary and sufficient conditions of feasibility. Taking account of resource constraints leads to defining disjunctive constraints. To this end, disjunctive sets of arcs are introduced, making the TBON graph nonconjunctive. In this case, a complete characterization of feasibility cannot reasonably be faced, due to the combinatorial feature. Nevertheless, a polynomial algorithm that applies reduction and deletion rules on the nonconjunctive part of the graph is proposed to restart new propagations on the conjunctive part until all deductions have been made.     

Checking the temporal integrity of interactive multimedia documents

Abstract. When authoring multimedia scenarios, and in particular scenarios with user interaction, where the sequence and time of occurrence of interactions is not predefined, it is difficult to guarantee the consistency of the resulting scenarios. As a consequence, the execution of the scenario may result in unexpected behavior or inconsistent use of media. The present paper proposes a methodology for checking the temporal integrity of interactive multimedia document (IMD) scenarios at authoring time at various levels. The IMD flow is mainly defined by the events occurring during the IMD session. Integrity checking consists of a set of discrete steps, during which we transform the scenario into temporal constraint networks representing the constraints linking the different possible events in the scenario. Temporal constraint verification techniques are applied to verify the integrity of the scenario, deriving a minimal network, showing possible temporal relationships between events given a set of constraints. Received June 9, 1998 / Accepted November 10, 1999     

Specifying real-time properties with metric temporal logic

This paper is motivated by the need for a formal specification method for real-time systems. In these systemsquantitative temporal properties play a dominant role. We first characterize real-time systems by giving a classification of such quantitative temporal properties. Next, we extend the usual models for temporal logic by including a distance function to measure time and analyze what restrictions should be imposed on such a function. Then we introduce appropriate temporal operators to reason about such models by turning qualitative temporal operators into (quantitative) metric temporal operators and show how the usual quantitative temporal properties of real-time systems can be expressed in this metric temporal logic. After we illustrate the application of metric temporal logic to real-time systems by several examples, we end this paper with some conclusions.Part of this research has been performed at the Eindhoven University of Technology when the author was working in ESPRIT project 937: Debugging and Specification of Ada Real-Time Embedded Systems (DESCARTES).     

HMAP– A temporal data model managing intervals with different granularities and indeterminacy from natural language sentences

The granularity of given temporal information is the level of abstraction at which information is expressed. Different units of measure allow one to represent different granularities. Indeterminacy is often present in temporal information given at different granularities: temporal indeterminacy is related to incomplete knowledge of when the considered fact happened. Focusing on temporal databases, different granularities and indeterminacy have to be considered in expressing valid time, i.e., the time at which the information is true in the modeled reality. In this paper, we propose HMAP (The term is the transliteration of an ancient Greek poetical word meaning “day”.), a temporal data model extending the capability of defining valid times with different granularity and/or with indeterminacy. In HMAP, absolute intervals are explicitly represented by their start,end, and duration: in this way, we can represent valid times as “in December 1998 for five hours”, “from July 1995, for 15 days”, “from March 1997 to October 15, 1997, between 6 and 6:30 p.m.”. HMAP is based on a three-valued logic, for managing uncertainty in temporal relationships. Formulas involving different temporal relationships between intervals, instants, and durations can be defined, allowing one to query the database with different granularities, not necessarily related to that of data. In this paper, we also discuss the complexity of algorithms, allowing us to evaluate HMAP formulas, and show that the formulas can be expressed as constraint networks falling into the class of simple temporal problems, which can be solved in polynomial time. Received 6 August 1998 / Accepted 13 July 2000 Published online: 13 February 2001     

Bases for closed sets of implicants and implicates in temporal logic

Prime implicates and implicants are used in several areas of Artificial Intelligence. However, their calculation is not always an easy task. Nevertheless, it is important to remark the distinction between (i) computing the prime implicates and implicants and (ii) using the information they contain. In this paper, we present a way in which (ii) can be done without actually doing (i) by limiting prime implicants and implicates management to unitary implicants and implicates. Besides, we outline how the use of this technique is particularly relevant in the field of automated deduction in temporal logics. The information contained in temporal implicates and implicants can be used to design transformations of temporal formulae able to increase the power of automated deduction techniques for temporal logics. Particularly, we have developed a theory for unitary temporal implicates and implicants that can be more efficiently computed than prime implicants, while still providing the information needed to design this kind of transformations. The theory we have developed in this paper is easily extensible to cover different types of temporal logics, and is integrable in different automated deduction methods for these temporal logics. Received: 14 May 1999 / 22 March 2002     

Enhancing a dependable multiserver operating system with temporal protection via resource reservations

Nowadays, microkernel-based systems are getting studied and adopted with a renewed interest in a wide number of IT scenarios. Their advantages over classical monolithic solutions mainly concern the dependability domain. By being capable of dynamically detect and solve non-expected behaviours within its core components, a microkernel-based OS would eventually run forever with no need to be restarted. Dependability in this context mainly aims at isolating components from a spatial point of view: a microkernel-based system may definitely not be adopted in the context of real-time environments, simply basing on this kind of protection only. One of the most active real-time research areas concerns adding temporal protection mechanisms to general purpose operating systems. By making use of such mechanisms, these systems become suitable for being adopted in the context of time-sensitive domains. Microkernel-based systems have always been thought of as a kind of platform not suited to real-time contexts, due to the high latencies introduced by the message passing technique as the only inter-process communication (IPC) facility within the system. With computer performances growing at a fairly high rate, this overhead becomes negligible with respect to the typical real-time processing times. In the last years, many algorithms belonging to the class of the so-called Resource Reservations (RRES) have been devised in order to provide the systems with the needed temporal isolation. By introducing a RRES-aware scheduler in the context of a microkernel-based system, we may enrich it with the temporal benefits it needs in order to be deployed within domains with real-time requirements. In this paper we propose a generic way to implement these mechanisms, dependent for a very small part on the underlying OS mechanisms. In order to show the generality of our RRES framework we implemented it in the context of Minix 3, a highly dependable microkernel-based OS with an impressive users base.