5811489
Java-based query driven simulation environment
The concept of Web-based simulation can be finally realized using Java. We have used Java to create a powerful simulation modeling library which is based on the process interaction paradigm. Java threads make it easy for us to implement each process (or active entity) as a thread. Our library, JSIM, supports both simulation and animation thus rendering the model developer's job easier. An important component of our approach is that we integrate our Java Simulator with a Database Management System (DBMS). The conceptual basis for this integration is an environment based on Query Driven Simulation, which allows simulation analysts to study the performance of systems simply by querying a database. Simulation inputs and outputs are stored in databases, and simulation models can be launched as a part of query processing. This integration also resolves a security restriction problem which Java imposes. Most browsers (e.g., Netscape Navigator) restrict Java applets from writing into a file which may be necessary to make simulation results available to the user. Our approach bypasses this problem by writing into a database. Databases are much less of a security concern since they already have substantial authorization mechanisms.
3039342
Adding Semantics to Web Services Standards
With the increasing growth in popularity of Web services, discovery of relevant Web services becomes a significant challenge. One approach is to develop semantic Web services where by the Web services are annotated based on shared ontologies, and use these annotations for semantics-based discovery of relevant Web services. We discuss one such approach that involves adding semantics to WSDL using DAML+OIL ontologies. Our approach also uses UDDI to store these semantic annotations and search for Web services based on them. We compare our approach with another initiative to add semantics to support Web service discovery, and show how our approach may fit current standards-based industry approach better.
30146652
Workflow Quality of Service
Workflow management systems (WfMSs) have been used to support various types of business processes for more than a decade now. In ecommerce processes, suppliers and customers define a binding agreement or contract between the two parties, specifying quality of service (QoS) items such as products or services to be delivered, deadlines, quality of products, and cost of service. Management of such QoS directly impacts success of organizations participating in e-commerce. Organizations operating in modern markets require an excellent degree of quality of service management. Products and services must be available to customers with well-defined specifications. A good management of quality leads to the creation of quality products and services, which in turn fulfills customer expectations and achieves customer satisfaction. Therefore, when services or products are created or managed using workflow processes, the underlying WfMS must accept the specification, be able to predict, monitor, and control the QoS rendered to customers. To achieve these objectives the first step is to develop an adequate QoS model for workflow processes and develop methods to compute QoS.
2346213
Healthcare Enterprise Process Development and Integration
Healthcare enterprises involve complex processes that span diverse groups and organisations. These processes involve clinical and administrative tasks, large volumes of data, and large numbers of patients and personnel. The tasks can be performed either by humans or by automated systems. In the latter case, the tasks are supported by a variety of software applications and information systems which are very often heterogeneous, autonomous, and distributed. The development of systems to manage and automate these processes has increasingly played an important role in improving the efficiency of healthcare enterprises. In this paper we look at four healthcare and medical applications that involve investigative, clinical, and administrative functions. Based on these applications, we derive the requirements for developing enterprise applications that involve the coordination of a variety of tasks performed by humans, information systems, and legacy applications.
9294328
Performance Modeling of Database Recovery Protocols
The performance modeling described in this paper compares several protocols which ensure that a database can be recovered to a consistent state after a transaction failure or system crash. The contributions of the paper include a collection of simple analytic models, based on Markov processes, for these protocols and some surprising results on the relative performance of the protocols. We consider only two-stage transactions (all reads before writes) and ignore effects of serializing transactions. The most interesting performance result presented is that, for systems obeying the assumptions of this paper, the "pessimistic" policy of holding write locks to commit point is considerably less efficient than the "optimistic" policy which allows reading of uncommitted data, but risks cascading aborts. A multiversion policy introduced in [2] was also studied and found always to be nearly as good as the optimistic policy and sometimes much better.
15234568
Demonstrating Dynamic Configuration and Execution of Web Processes
Web processes are next generation workflows on the web, created using Web services. In this paper we demonstrate the METEOR-S Configuration and Execution Environment (MCEE) system. It will illustrate the capabilities of the system to a) Discover partners b) Optimize partner selection using constraint analysis, c) Perform interaction protocol and data mediation. A graphical execution monitor to monitor the various phases of execution will be used to demonstrate various aspects of the system.
1173889
Effectiveness for infinite variable words and the Dual Ramsey Theorem
Abstract.We examine the Dual Ramsey Theorem and two related combinatorial principles VW(k,l) and OVW(k,l) from the perspectives of reverse mathematics and effective mathematics. We give a statement of the Dual Ramsey Theorem for open colorings in second order arithmetic and formalize work of Carlson and Simpson [1] to show that this statement implies ACA0 over RCA0. We show that neither VW(2,2) nor OVW(2,2) is provable in WKL0. These results give partial answers to questions posed by Friedman and Simpson [3].
42866634
SensorMap: a Web site for sensors world-wide
Local mash up.
7380263
Getting more from the data in a multinomial selection problem
We consider the problem of determining which of k simulated systems is most likely to be the best per former based on some objective performance measure. The standard experiment is to generate v in dependent vector observations (replications) across the k- systems. A classical multinomial selection pro cedure, BEM (Bechhofer, Elmaghraby, and Morse), prescribes a minimum number of replications so that the probability of correctly selecting the true best system meets or exceeds a prespecified probability. Assuming that larger is better, BEM selects as best the system having the largest value of the performance measure in more replications than any other. We propose using these same v replications across k systems to form vk pseudoreplications (no longer in dependent) that contain one observation from each system, and again select as best the system having the largest value of the performance measure in more pseudoreplications than any other. We expect that this new procedure, AVC (all vector comparisons), dominates BEM in the sense that AVC will never require more independent replications than DEM to meet a prespecified probability of correct selection. We present analytical and simulation results to show how AVC fares versus BEM for different underly ing distribution families, different numbers of populations and various values of v. We also present results for the closely related problem of estimating the probability that a specific system is the best.
8365397
Input modeling when simple models fail
A simulation model is composed of inputs and logic; the inputs represent the uncertainty or randomness in the system, while the logic determines how the system reacts to the uncertain elements. Simple input models, consisting of independent and identically distributed sequences of random variates from standard probability distributions, are included in every commercial simulation language. Software to fit these distributions to data is also available. In this tutorial we describe input models that are useful when simple models are not.
7900596
On self-embeddings of computable linear orderings
The Dushnik{Miller Theorem states that every innite countable linear ordering has a nontrivial self-embedding. We examine computability-theoretical aspects of this classical theorem.