, Exception, Clock, Externalg Granularity ae fMember, Subset, Setg Type ae fPrimitive, Composite g Operators ae for, and, seq, closure, times, not g Consumption mode ae fRecent, Chronicle, Cumulative, Continuous g Role 2 fMandatory, Optional, Noneg Condition Role 2 fMandatory, Optional, Noneg Context ae fDB T , BindE , DBE , DBC g Action Options ae fStructure Operation, Behavior Invocation, Update-Rules, Abort Inform, External, Do Instead g Context ae fDB T , BindE , BindC , DBE , DBC , DBA g ---behavior invocation, in which case the event is raised by the execution of some user-defined operation (e.g. the message display is sent to an object of type widget). It is common for event languages to allow events to be raised before or after an operation has been executed. ---transaction, in which case the event is raised by transaction commands (e.g. abort, commit, begin-transaction) ---abstract or user-defined, in which case a programming mechanism is used that allows an appli...

A number of effective error detection tools have been built in recent years to check if a program conforms to certain design rules. An important class of design rules deals with sequences of events associated with a set of related objects. This paper presents a language called PQL (Program Query Language) that allows programmers to express such questions easily in an application-specific context. A query looks like a code excerpt corresponding to the shortest amount of code that would violate a design rule. Details of the target application's precise implementation are abstracted away. The programmer may also specify actions to perform when a match is found, such as recording relevant information or even correcting an erroneous execution on the fly.

Modern window-based user interface systems generate user interface events as natural products of their normal operation. Because such events can be automatically captured and because they indicate user behavior with respect to an application's user interface, they have long been regarded as a potentially fruitful source of information regarding application usage and usability. However, because user interface events are typically voluminos and rich in detail, automated support is generally required to extract information at a level of abstraction that is useful to investigators interested in analyzing application usage or evaluating usability. This survey examines computer-aided techniques used by HCI practitioners and researchers to extract usability-related information from user interface events. A framework is presented to help HCI practitioners and researchers categorize and compare the approaches that have been, or might fruitfully be, applied to this problem. Because many of the techniques in the research literature have not been evaluated in practice, this survey provides a conceptual evaluation to help identify some of the relative merits and drawbacks of the various classes of approaches. Ideas for future research in this area are also presented. This survey addresses the following questions: How might user interface events be used in evaluating usability? How are user interface events related to other forms of usability data? What are the key challenges faced by investigators wishing to exploit this data? What approaches have been brought to bear on this problem and how do they compare to one another? What are some of the important open research questions in this area?

Falcon is a system for on-line monitoring and steering of large-scale parallel programs. The purpose of such interactive steering is to improve its performance or to affect its execution behavior. The Falcon system is composed of an application-specific on-line monitoring system, an interactive steering mechanism, and a graphical display system. In this paper, we present a framework of the Falcon system, its implementation, and evaluation of the system performance. A complex sample application -- a molecular dynamics simulation program (MD) -- is used to motivate the research as well as to evaluate the performance of the Falcon system. 1 Introduction The high performance of current parallel supercomputers is permitting users to interact with their applications during program execution. Such interactive executions of large-scale parallel codes typically make use of multiple networked machines working in concert on behalf of a single user, as computational engines, display engines, inpu...

Event-based systems are developed and used to integrate components in loosely coupled systems. Research and product development focused so far on e#ciency issues but neglected methodological support to build such systems. In this article, the modular design and implementation of an event system is presented which supports scopes and event mappings, two new and powerful structuring methods that facilitate engineering and coordination of components in event-based systems. We give a

It is important to have continuously updated information about network resources and application activities after a wireless sensor network is deployed in unpredictable environment. Such information can help notify users of resource depletion or abnormal activities. However, the low user-to-node ratio and limited energy and bandwidth resources in sensor networks make extracting states from each individual node infeasible. In this paper, we propose an approach to construct abstracted scans of sensor network health by applying in-network aggregation of network states. Specifically, we design a residual energy scan that approximately depicts the remaining energy distribution within a sensor network. Simulations show that our approach has good scalability and energy-efficiency characteristics, compared to continuously extracting the residual energy individually from each node.

Event based monitoring is critical for managing and debugging networks and distributed systems. This paper presents GEM -- an interpreted Generalised Event Monitoring language. It allows high level, abstract events to be specified in terms of combinations of lower level events from different nodes in a loosely coupled distributed system. Event monitoring components can thus be distributed within the system to perform filtering, correlation and notification of events close to where they occur and thus reduce network traffic. GEM is a declarative rule based language in which the notion of real time has been closely integrated and various temporal constraints can be specified for event composition. The paper discusses the effect of communication delays on composite event detection and presents a tree-based solution for dealing with out-of-order event arrivals at event monitors. Keywords: Monitoring distributed systems, event reporting, event correlation, event filtering, composite event...

Empirical evaluation of software systems in actual usage situations is critical in software engineering. Prototyping, beta testing, and usability testing are widely used to refine system requirements, detect anomalous or unexpected system and user behavior, and to evaluate software usefulness and usability. The World Wide Web enables cheap, rapid, and large-scale distribution of software for evaluation purposes. However, current techniques for collecting usage data have not kept pace with the opportunities presented by Web-based deployment. This paper presents an approach and prototype system that makes large-scale collection of usage data over the Internet a practical possibility. A general framework for comparing software monitoring systems is presented and used to compare the proposed approach to existing techniques.

this article.

Advances in high performance computing, communications, and user interfaces enable developers to construct increasingly interactive high performance applications. The Falcon system presented in this paper supports such interactivity by providing runtime libraries, tools, and user interfaces that permit the on-line monitoring and steering of large-scale parallel codes. The principal aspects of Falcon described in this paper are its abstractions and tools for capture and analysis of application-specific program information, performed on-line, with controlled latencies and scalable to parallel machines of substantial size. In addition, Falcon provides support for the on-line graphical display of monitoring information, and it allows programs to be steered during their execution, by human users or algorithmically. This paper presents our basic research motivation, outlines the Falcon system's functionality, and includes a detailed evaluation of its performance characteristics in light of i...