Databases and Information Systems Commons^™

Link Lifetimes And Randomized Neighbor Selection In Dhts, Zhongmei Yao, Dmitri Loguinov

Computer Science Faculty Publications

Several models of user churn, resilience, and link lifetime have recently appeared in the literature [12], [13], [34], [35]; however, these results do not directly apply to classical Distributed Hash Tables (DHTs) in which neighbor replacement occurs not only when current users die, but also when new user arrive into the system, and where replacement choices are often restricted to the successor of the failed zone in the DHT space. To understand neighbor churn in such networks, this paper proposes a simple, yet accurate, model for capturing link dynamics in structured P2P systems and obtains the distribution of link lifetimes …

An Augmented Approach To Support Collaborative Distance Learning Of Unified Modeling Language, Keng Siau, Fiona Fui-Hoon Nah, Brenda Eschenbrenner, Ashu Guru

Research Collection School Of Computing and Information Systems

Teaching in the classroom faces many challenges of providing a collaborative, interactive environment that effectively facilitates students’ learning. The challenges increase when the physical classroom converts into a virtual classroom. This difficulty is further exacerbated when the course is diagramming intensive, practice-oriented, and hands-on in nature. Technology has been sought after to help with these challenges. Web Conferencing software, when compared to Web Broadcasting software, can facilitate real-time interaction and collaboration in a distance learning context. For courses that are diagramming intensive and practice-oriented, Tablet PCs, when compared to desktop PCs, can support drawing and diagramming because of the ability …

Modeling Heterogeneous User Churn And Local Resilience Of Unstructured P2p Networks, Zhongmei Yao, Derek Leonard, Dmitri Loguinov, Xiaoming Wang

Computer Science Faculty Publications

Previous analytical results on the resilience of unstructured P2P systems have not explicitly modeled heterogeneity of user churn (i.e., difference in online behavior) or the impact of in-degree on system resilience. To overcome these limitations, we introduce a generic model of heterogeneous user churn, derive the distribution of the various metrics observed in prior experimental studies (e.g., lifetime distribution of joining users, joint distribution of session time of alive peers, and residual lifetime of a randomly selected user), derive several closed-form results on the transient behavior of in-degree, and eventually obtain the joint in/out degree isolation probability as a simple …

Agile Modeling, Agile Software Development, And Extreme Programming: The State Of Research, John Erickson, Kalle Lyytinen, Keng Siau

Research Collection School Of Computing and Information Systems

While there are many claims for the successful use of extreme programming (XP) and agile modeling (AM), and the proponents can often be vocal in the extreme regarding their supposed benefits, research evidence supporting proponents' claims is somewhat lacking. Currently, the only research appearing to investigate the phenomena consists of two prominent streams. A small number of case studies and experience reports that generally promote the success of XP in various development environments, and a well-established stream of research into pair programming has generated results that in part support the idea of XP. Research into AM appears to be even …

Enhanced Risk Analysis-Relative Impact Factorization, Basit Shahzad, Tanveer Afzal, Rizwana Irfan

International Conference on Information and Communication Technologies

Software engineering is an area of development which always has the risk factor present and software engineering can hardly be done on some straight line. So, the manager has to handle the dynamically changing circumstances in order to complete the job. The target of development team is to develop the software according to the requirements within specified time. Wide variety of risks I are present that may grab the development effort. A good manager must ensure that all measures have been taken against the risks that may possibly come. This paper focuses on determining the relative impact of risk factors …

An Investigation Into The Continued Use Of Unified Modeling Language (Uml) In Information Systems Development, Keng Siau, X. Tan

Research Collection School Of Computing and Information Systems

As the de facto standard for object-oriented modeling language, UML is expected to play an increasingly important role in information systems development. The long-term viability and eventual success of UML depend, to a great extent, on the continued use by UML users such as developers and analysts. Systematic investigations on UML’s continued use have been missing from contemporary discussions. Our study attempts to fill this gap in the literature. We developed a research model, which is primarily based on the Expectation Disconfirmation Theory (EDT). According to this model, UML users’ perceived discrepancy between pre-adoption expectation and post-adoption perceived performance, which …

Automatically Discovering The Number Of Clusters In Web Page Datasets, Zhongmei Yao

Computer Science Faculty Publications

Clustering is well-suited for Web mining by automatically organizing Web pages into categories, each of which contains Web pages having similar contents. However, one problem in clustering is the lack of general methods to automatically determine the number of categories or clusters. For the Web domain in particular, currently there is no such method suitable for Web page clustering. In an attempt to address this problem, we discover a constant factor that characterizes the Web domain, based on which we propose a new method for automatically determining the number of clusters in Web page data sets. We discover that the …

Jess – A Java Security Scanner For Eclipse, Russell Spitler

Honors Theses

Secure software is the responsibility of every developer. In order to help a developer with this responsibility there are many automated source code security auditors. These tools perform a variety of functions, from finding calls to insecure functions to poorly generated random numbers. These programs have existed for years and perform the security audit with varying degrees of success.

Largely missing in the world of programming is such a security auditor for the Java programming language. Currently, Fortify Software produces the only Java source code security auditor; this is a commercially available package.

This void is what inspired JeSS, Java …

Theoretical And Practical Complexity Of Unified Modeling Language: Delphi Study And Metrics Analyses, J. Erickson, Keng Siau

Research Collection School Of Computing and Information Systems

Systems have become increasingly complex, and as a result development methods have become more complex as well. The unified modeling language (UML) has been criticized for the often cited and sometimes over- whelming complexity it presents to its users, and those seeking to learn to use it. Using Rossi and Brinkkemper’s (1996) complexity metrics, Siau and Cao (2001) completed a complexity analysis of UML and 36 other modeling techniques, finding that UML is indeed more complex than other techniques. Siau, Erickson and Lee (2002) proposed that Rossi and Brinkkemper’s metrics present the theoretical maximum complexity, known as theoretical complexity. This …

Staging Transformations For Multimodal Web Interaction Management, Michael Narayan, Christopher Williams, Saverio Perugini, Naren Ramakrishnan

Computer Science Faculty Publications

Multimodal interfaces are becoming increasingly ubiquitous with the advent of mobile devices, accessibility considerations, and novel software technologies that combine diverse interaction media. In addition to improving access and delivery capabilities, such interfaces enable flexible and personalized dialogs with websites, much like a conversation between humans. In this paper, we present a software framework for multimodal web interaction management that supports mixed-initiative dialogs between users and websites. A mixed-initiative dialog is one where the user and the website take turns changing the flow of interaction. The framework supports the functional specification and realization of such dialogs using staging transformations – …

Program Transformations For Information Personalization, Saverio Perugini

Computer Science Faculty Publications

Personalization constitutes the mechanisms and technologies necessary to customize information access to the end-user. It can be defined as the automatic adjustment of information content, structure, and presentation. The central thesis of this dissertation is that modeling interaction explicitly in a representation, and studying how partial information can be harnessed in it by program transformations to direct the flow of the interaction, can provide insight into, reveal opportunities for, and define a model for personalized interaction. To evaluate this thesis, a formal modeling methodology is developed for personalizing interactions with information systems, especially hierarchical hypermedia, based on program transformations. The …

Supply Chains Integration: Architecture And Enabling Technologies, Keng Siau, Yuhong Tian

Research Collection School Of Computing and Information Systems

An effective and efficient supply chain is vital to the competitiveness and the survival of an organization. With the emergence of the e-business era, supply chain systems need to be able to extend beyond the traditional boundaries. This paper proposes integrated supply chain architecture (SCA) that combines the benefits of Enterprise Resource Planning (ERP) and the various supply chain applications. Some necessary criteria for an integrated supply chain include completeness, security, flexibility, scalability, and interoperability. The enabling technologies for such a supply chain system include XML, DCOM, CORBA, SOAP, Net, and Semantic Web. Wireless and mobile technologies could further extend …

Development Of A Systems Engineering Model For Chemical Separation Process, Lijian Sun

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis is concerned with the efforts to develop a general-purpose systems engineering model software TRPSEMPro1 that can be used to improve productivity in the design process. Different features of TRPSEMPro will be presented in this thesis. First, Systems Engineering technology is presented, followed by the exposition of different numerical optimization technologies and DOE (Design of Experiments) study technologies. Second, the detailed software process, Object-Oriented Analysis and Design (OOA&D) for the TRPSEMPro is presented. All the design data models are expressed by using Unified Modeling Language (UML).

AMUSESimulator is another software package which has been designed and implemented in order …

Personalizing Interactions With Information Systems, Saverio Perugini, Naren Ramakrishnan

Computer Science Faculty Publications

Personalization constitutes the mechanisms and technologies necessary to customize information access to the end-user. It can be defined as the automatic adjustment of information content, structure, and presentation tailored to the individual. In this chapter, we study personalization from the viewpoint of personalizing interaction. The survey covers mechanisms for information-finding on the web, advanced information retrieval systems, dialog-based applications, and mobile access paradigms. Specific emphasis is placed on studying how users interact with an information system and how the system can encourage and foster interaction. This helps bring out the role of the personalization system as a facilitator which reconciles …

Analyzing Unified Modeling Language Using Concept Mapping, Keng Siau, Z. Shen

Research Collection School Of Computing and Information Systems

The Unified Modeling Language (UML) is a visual modeling language for object-oriented software development. Although the Object Management Group (OMG) adopted UML as its standard modeling language in 1997, the consensus in the academic community and the industry is that further research is needed to evaluate, enhance, extend, and formalize UML. A substantial amount of research has been conducted to this end, but most was based on common sense, informal observation, and intuition. Systematic and empirical studies to analyze, evaluate, and enhance UML have been lacking. This paper attempts to evaluate and study UML from a cognitive perspective. Specifically, the …

Meeting Medical Terminology Needs: The Ontology-Enhanced Medical Concept Mapper, Gondy Leroy, Hsinchun Chen

CGU Faculty Publications and Research

This paper describes the development and testing of the Medical Concept Mapper, a tool designed to facilitate access to online medical information sources by providing users with appropriate medical search terms for their personal queries. Our system is valuable for patients whose knowledge of medical vocabularies is inadequate to find the desired information, and for medical experts who search for information outside their field of expertise. The Medical Concept Mapper maps synonyms and semantically related concepts to a user's query. The system is unique because it integrates our natural language processing tool, i.e., the Arizona (AZ) Noun Phraser, with human-created …

The Partial Evaluation Approach To Information Personalization, Naren Ramakrishnan, Saverio Perugini

Computer Science Faculty Publications

Information personalization refers to the automatic adjustment of information content, structure, and presentation tailored to an individual user. By reducing information overload and customizing information access, personalization systems have emerged as an important segment of the Internet economy. This paper presents a systematic modeling methodology— PIPE (‘Personalization is Partial Evaluation’) — for personalization. Personalization systems are designed and implemented in PIPE by modeling an information-seeking interaction in a programmatic representation. The representation supports the description of information-seeking activities as partial information and their subsequent realization by partial evaluation, a technique for specializing programs. We describe the modeling methodology at a …

Unified Modeling Language: A Complexity Analysis, Keng Siau, Q. Cao

Research Collection School Of Computing and Information Systems

Unified Modeling Language (UML) is the standard visual modeling language for Object Oriented (OO) systems development, but it has been criticized for its complexity, inconsistent semantics, and ambiguous constructs. A set of complexity indices for UML and the nine diagramming techniques in UML was compiled recently. The complexity analysis is formulated based on the number of constructs, associations, roles, and so forth, in a modeling method. We argue that this set of metrics provides an indication of the theoretical complexity of the modeling methods. On the other hand, the theoretical complexity of the modeling methods does not necessarily relate to …

Structured Web Databases, Shuang Li

Dissertations and Theses

Recent research has focused on the cooperation of web server and database server software in the deployment of data-intensive web sites. That work has focused either on storing data in a database that can be used to generate the contents of a web site, or on providing interfaces and gateways to enable queries to be invoked from web pages and executed at external database servers.

This thesis describes the implementation of a prototype of the Data Web system that is being implemented at Portland State University. With Data Web, a user can embed in a web page virtual tables that …

Development Of A Reusable Object Oriented Application Framework For Library Systems Domain, Roy Teck Choye Chew

Student Works (2000-2009)

The main goal of developing an application framework on an application domain or a business domain is to facilitate development of application systems within the same domain by reusing components through customisation and not from scratch. These components would have to be analysed and designed with reusable features so that they can be reused to develop different applications in the related domain. In the case of an object-oriented application framework in the technical view, it is made up of a set of interrelated abstract (generic) and concrete classes that underlie the components of a domain model and form the domain …

Measurement Of The W Mass In E+E- Collisions At 183 Gev, Barate, R.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

The mass of the W boson is obtained from reconstructed invariant mass distributions in W-pair events. The sample of W pairs is selected from 57 pb−1 collected with the ALEPH detector in 1997 at a centre-of-mass energy of 183 GeV.

A Study Of Single W Production In E+E- Collisions At √S = 161-183 Gev, R. Barate, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

Single W production is studied in the data recorded with the ALEPH detector at LEP at centre-of-mass energies between 161 and 183 GeV. The cross section is measured to be σw = 0.41 ± 0.17(stat.) ± 0.04(syst.) pb at 183 GeV, consistent with the Standard Model expectation. Limits on non-standard WWγ couplings are deduced as -1.6 γ γ = 0) and -1.6 γ γ = 1) at 95% C.L. A search for effectively invisible decays of the W boson in W pair production is performed, leading to an upper limit on the branching ratio of 1.3% (Γinv = 27 MeV) …

Measurement Of W-Pair Production In E+E- Collisions At 183 Gev, R. Barate, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

The production of W+W− pairs is analysed in a data sample collected by ALEPH at a mean centre-of-mass energy of 182.7 GeV, corresponding to an integrated luminosity of 57 pb−1 . Cross sections are given for different topologies of W decays into leptons or hadrons. Under Standard Model assumptions for the W-pair production and decay, the W-pair cross section is measured to be 15.57 ± 0.62(stat.) ± 0.29(syst.) pb. Using also the W-pair data samples collected by ALEPH at lower centre-of-mass energies, the decay branching ratio of the W boson into hadrons is measured to be B(W → hadrons) = …

Monitoring The Stability Of The Aleph Vertex Detector, G. Sguazzoni, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

The ALEPH Silicon Vertex Detector features an optical fibre laser system to monitor its mechanical stability. The operating principle and the general performance of the laser system are described. The experience obtained during 1997 and 1998 operations confirms the important role that such a system can have with respect to the detector alignment requirements. In particular, the laser system has been used to monitor short-term temperature-related effects and long-term movements. These results and a description of the laser-based alignment correction applied to the 1998 data are presented.

Search For Invisible Higgs Boson Decays In E+E- Collisions At Centre-Of-Mass Energies Up To 184 Gev, R. Barate, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

In a data sample of 78.3 pb−1 collected in 1996 and 1997 by the ALEPH detector at centre-of-mass energies from 161 to 184 GeV, invisible decays of a Higgs boson have been searched for in the reaction e+e− → hZ, where the Z can decay into e+e−, µ+µ− or q¯q. No evidence for a signal is found and limits on the production cross section are derived as a function of the Higgs boson mass. These results are combined with those obtained in an update of the analyses of the ALEPH data taken at LEP 1. For a production cross section …

Determination Of The Lep Centre-Of-Mass Energy From Zγ Events, R. Barate, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

A study of events with photons and missing energy has been performed with the data sample obtained with the ALEPH detector at centre-of-mass energies from 161 to 184 GeV, corresponding to a total integrated luminosity of about 80 pb−1. The measured distributions are in agreement with Standard Model predictions, leading to constraints on WWγ gauge coupling parameters ∆κγ and λγ. The results from the fit to the cross sections and to the energy and angular distributions of the photons are: ∆κγ = 0.05+1.15 −1.10(stat)±0.25(syst) λγ = −0.05+1.55 −1.45(stat)±0.30(syst).

Measurement Of The Hadronic Photon Structure Function At Lep 1 For 〈Q2〉 Values Between 9.9 And 284 Gev2, Barate, R.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

Inclusive γ∗γ interactions to hadronic final states where one scattered electron or positron is detected in the electromagnetic calorimeters have been studied in the LEP 1 data taken by ALEPH from 1991 to 1995. The event sample has been used to measure the hadronic structure function of the photon F2γ in three bins with 〈Q2〉 of 9.9, 20.7 and 284 GeV2.

Search For Sleptons In E+E- Collisions At Centre-Of-Mass Energies Up To 184 Gev Aleph Collaboration, R. Barate, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

The data collected by the ALEPH experiment at LEP at centre–of–mass energies around 183 GeV are analysed to search for sleptons, the partners of leptons in supersymmetric theories. The previously published search for acoplanar leptons and missing energy has been updated. New searches have been developed to cover a wider range of slepton signals. These include single electrons, acoplanar leptons accompanied by two photons plus missing energy as well as particles with lifetime. No evidence for the production of any such particles is found. Slepton mass limits are reported within gravity mediated and gauge mediated SUSY breaking scenarios.

The Forward-Backward Asymmetry For Charm Quarks At The Z, R. Barate, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

From 1.4 million hadronic Z decays collected by the ALEPH detector at LEP, an enriched sample of Z → cc̄ events is extracted by requiring the presence of a high momentum D∗±. The charm quark forward-backward charge asymmetry at the Z pole is measured to be AFB0.c = (8.0 ± 2.4) % corresponding to an effective electroweak mixing angle of sin2θWeff = 0.2302 ± 0.0054.

A Measurement Of The Inclusive B → Sγ Branching Ratio, R. Barate, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

The avour changing neutral current decay b ! s has been detected in hadronic Z decays collected by ALEPH at LEP. The signal is isolated in lifetime-tagged b b events by the presence of a hard photon associated with a system of high momentum and high rapidity hadrons. The background processes are normalised from the data themselves. The inclusive branching ratio is measured to be (3:11 0:80stat 0:72syst) 104 ; consistent with the Standard Model expectation via penguin processes