Comparison of web service architecture based on architecture quality properties

Web service research has been focused on the issues of automatic binding, performance, scalability, and security, however, little research has been done in evaluation of web service architectures, namely Broker based. Examples of these are Matchmaker Broker, Layered Matchmaker, Facilitator, Layered facilitator, and Peer to peer (P2P) based, such as P2P Discovery, Match Maker and P2P, Split Code and P2P execution, Mobile Code with P2P etc. Another consideration is its impact on the adoption in distributed Internet environment. In this paper we introduce a methodology for measuring and evaluating web service architecture style, and we present our development of a set of architectural quality properties, and use these quality properties to carry out comparison and contract of current web services architectures. We provide a detailed analysis and critique of these, and these could be served as a guidelines for the next generation of web services development, which could adopted into the distributed environment

Distributed Web Service Coordination for Collaboration Applications and Biological Workflows

In this dissertation work, we have investigated the main research thrust of decentralized coordination of workflows over web services. To address distributed workflow coordination, first we have developed “Web Coordination Bonds” as a capable set of dependency modeling primitives that enable each web service to manage its own dependencies. Web bond primitives are as powerful as extended Petri nets and have sufficient modeling and expressive capabilities to model workflow dependencies. We have designed and prototyped our “Web Service Coordination Management Middleware” (WSCMM) system that enhances current web services infrastructure to accommodate web bond enabled web services. Finally, based on core concepts of web coordination bonds and WSCMM, we have developed the “BondFlow” system that allows easy configuration distributed coordination of workflows. The footprint of the BonFlow runtime is 24KB and the additional third party software packages, SOAP client and XML parser, account for 115KB

Predicting suspended sediment in Illinois rivers using dimensionless rating curves

Suspended sediment concentrations in Illinois are a serious concern to the environment and navigability of Illinois rivers, the Mississippi River and the Gulf of Mexico. Therefore, understanding the amount of sediment in a river is important. Measuring the sediment, though, can be a lengthy, time-consuming, and expensive process. In this study, dimensionless suspended sediment concentrations are predicted in Illinois by creating dimensionless suspended sediment rating curves. Suspended sediment concentration (SSC) data, collected by the Illinois State Water Survey monitoring program, and discharge data, collected by the U.S. Geological Survey (USGS), from ten sites across the state of Illinois are used in the sediment rating curve analysis. Field measurements of bankfull height at each site were taken and cross-referenced with the USGS discharge to determine bankfull discharge. The suspended sediment concentration at that bankfull discharge is referred to as the bankfull suspended sediment concentration. Data at each site were normalized by dividing discharges and sediment concentrations by bankfull flow and bankfull suspended sediment concentrations, respectively. The first objective in this study is to examine if geomorphic and hydraulic parameters can increase the predictability of dimensionless suspended sediment concentrations from dimensionless discharges for rivers within Illinois. Rating curves using non-linear least squares regression with an additive coefficient for individual watersheds, when limiting discharge data to either the rising limb or falling limb of the hydrograph yielded predictive sediment models. The data from all watersheds were then combined and normalized to create a dimensionless sediment rating curve for Illinois. Model efficiency was low, but improved when data was subdivided by landuse, channel slope, or drainage area. Forested watersheds of less than 1000 square miles with channel slopes greater than 0.0004 trended toward the most predictive dimensionless sediment rating curves for Illinois rivers. The second objective is to evaluate the effect of seasons on dimensionless suspended sediment rating curves. Nash-Sutcliffe efficiency coefficients were as high as 0.93 for non-linear with an additive coefficient regression models when individual watersheds are evaluated using data from summer months only (April – September). Sediment rating curve model efficiency was also high for combined watershed data when subdivided into two seasons: winter and summer. The similarities in precipitation and runoff during the summer months (April – September), as opposed to the winter months (October – March), assists in creating a predictive model for suspended sediment concentrations during each of those timeframes. The third objective is to compare Illinois dimensionless suspended sediment rating curves to previous research performed on Colorado streams (Rosgen, 2007) to determine if one dimensionless rating curve is applicable to rivers in multiple locations across the United States. When the Colorado dimensionless sediment rating curve was compared to the ten studied Illinois watersheds, few similarities were found. Additional smaller watersheds within Illinois were compared to the Colorado curves, however, and show close visual agreement between modeled data and measured data. Quantification of the model efficiency for the small Illinois watersheds indicates that the Colorado curves have low predictability for Illinois streams. Overall, Illinois rivers create unique challenges for developing dimensionless sediment rating curves. The sand, silt and clay in the streambank and bed of Illinois rivers makes is easy for sediment particles to become suspended and remain suspended in the water column. Variability of management techniques between farm fields, rainfall distribution across large drainage areas, and in-stream disturbances contributing to sediment suspension (ie. log jams, animal activity, low-flow crossings) all hinder the predictability of a single sediment rating curve for Illinois rivers. Further study on small watersheds or on multiple locations of a single watershed will help to limit variability in the model and may lead to a more predictive solution to predicting suspended sediment concentrations within Illinois rivers

Exploiting general-purpose background knowledge for automated schema matching

The schema matching task is an integral part of the data integration process. It is usually the first step in integrating data. Schema matching is typically very complex and time-consuming. It is, therefore, to the largest part, carried out by humans. One reason for the low amount of automation is the fact that schemas are often defined with deep background knowledge that is not itself present within the schemas. Overcoming the problem of missing background knowledge is a core challenge in automating the data integration process. In this dissertation, the task of matching semantic models, so-called ontologies, with the help of external background knowledge is investigated in-depth in Part I. Throughout this thesis, the focus lies on large, general-purpose resources since domain-specific resources are rarely available for most domains. Besides new knowledge resources, this thesis also explores new strategies to exploit such resources. A technical base for the development and comparison of matching systems is presented in Part II. The framework introduced here allows for simple and modularized matcher development (with background knowledge sources) and for extensive evaluations of matching systems. One of the largest structured sources for general-purpose background knowledge are knowledge graphs which have grown significantly in size in recent years. However, exploiting such graphs is not trivial. In Part III, knowledge graph em- beddings are explored, analyzed, and compared. Multiple improvements to existing approaches are presented. In Part IV, numerous concrete matching systems which exploit general-purpose background knowledge are presented. Furthermore, exploitation strategies and resources are analyzed and compared. This dissertation closes with a perspective on real-world applications

Methods for Efficient and Accurate Discovery of Services

With an increasing number of services developed and offered in an enterprise setting or the Web, users can hardly verify their requirements manually in order to find appropriate services. In this thesis, we develop a method to discover semantically described services. We exploit comprehensive service and request descriptions such that a wide variety of use cases can be supported. In our discovery method, we compute the matchmaking decision by employing an efficient model checking technique

Combining SOA and BPM Technologies for Cross-System Process Automation

This paper summarizes the results of an industry case study that introduced a cross-system business process automation solution based on a combination of SOA and BPM standard technologies (i.e., BPMN, BPEL, WSDL). Besides discussing major weaknesses of the existing, custom-built, solution and comparing them against experiences with the developed prototype, the paper presents a course of action for transforming the current solution into the proposed solution. This includes a general approach, consisting of four distinct steps, as well as specific action items that are to be performed for every step. The discussion also covers language and tool support and challenges arising from the transformation

Modeling and acceleration of content delivery in world wide web

Ph.DDOCTOR OF PHILOSOPH