Databases and Information Systems Commons^™

A Novel Unbalanced Tree Structure For Low-Cost Authentication Of Streaming Content On Mobile And Sensor Devices, Thivya Kandappu, Vijay Sivaraman, Roksana Boreli

Research Collection School Of Computing and Information Systems

We consider stored content being streamed to a resource-poor device (such as a sensor node or a mobile phone), and address the issue of authenticating such content in realtime at the receiver. Per-packet digital signatures incur high computational cost, while per-block signatures impose high delays. A Merkle hash tree combines the benefits of the two by having a single signature per-block (at the root of the tree), while allowing immediate per-packet verification by following a hash-path logarithmic in the number of packets. In this paper we explore how the structure of the Merkle tree can be adapted to improve playback …

Overcoming The Challenges In Cost Estimation For Distributed Software Projects, Narayanasamy Ramasubbu, Rajesh Krishna Balan

Research Collection School Of Computing and Information Systems

We describe how we studied, in-situ, the operational processes of three large high process maturity distributed software development companies and discovered three common problems they faced with respect to early stage project cost estimation. We found that project managers faced significant challenges to accurately estimate project costs because the standard metrics-based estimation tools they used (a) did not effectively incorporate diverse distributed project configurations and characteristics, (b) required comprehensive data that was not fully available for all starting projects, and (c) required significant domain experience to derive accurate estimates. To address these challenges, we collaborated with practitioners at the three …

Effects Of Information Importance And Distribution On Information Exchange In Team Decision Making, Babajide James Osatuyi

Dissertations

Teams in organizations are strategically built with members from domains and experiences so that a wider range of information and options can be pooled. This strategic team structure is based on the assumption that when team members share the information they have, the team as a whole can access a larger pool of information than any one member acting alone, potentially enabling them to make better decisions. However, studies have shown that teams, unlike individuals, sometimes do not effectively share and use the unique information available to them, leading to poorer decisions. Research on information sharing in team decision making …

Integrating Owl And Rules: A Syntax Proposal For Nominal Schemas, David Carral Martinez, Adila Krisnadhi, Pascal Hitzler

Computer Science and Engineering Faculty Publications

This paper proposes an addition to OWL 2 syntax to incorporate nominal schemas, which is a new description-logic style extension of OWL 2 which was recently proposed, and which makes is possible to express "variable nominal classes" within axioms in an OWL 2 ontology. Nominal schemas make it possible to express DL-safe rules of arbitrary arity within the extended OWL paradigm, hence covering the well-known DL-safe SWRL language. To express this feature, we extend OWL 2 syntax to include necessary and minimal modifications to both Functional and Manchester syntax grammars and mappings from these two syntaxes to Turtle/RDF. We also …

Dynamic Scoping For Browser Based Access Control System, Vinaykumar Nadipelly

Masters Theses & Specialist Projects

We have inorganically increased the use of web applications to the point of using them for almost everything and making them an essential part of our everyday lives. As a result, the enhancement of privacy and security policies for the web applications is becoming increasingly essential. The importance and stateless nature of the web infrastructure made the web a preferred target of attacks. The current web access control system is a reason behind the victory of attacks. The current web consists of two major components, the browser and the server, where the effective access control system needs to be implemented. …

Semantic Aspects Of Earthcube, Pascal Hitzler, Krzysztof Janowicz, Gary Berg-Cross, Leo Obrst, Amit P. Sheth, Timothy Finin, Isabel F. Cruz

Kno.e.sis Publications

In this document, we give a high-level overview of selected Semantic (Web) technologies, methods, and other important considerations, that are relevant for the success of EarthCube. The goal of this initial document is to provide entry points and references for discussions between the Semantic Technologies experts and the domain experts within EarthCube. The selected topics are intended to ground the EarthCube roadmap in the state of the art in semantics research and ontology engineering.

We anticipate that this document will evolve as EarthCube progresses. Indeed, all EarthCube parties are asked to provide topics of importance that should be treated in …

Trust Networks, Krishnaprasad Thirunarayan, Pramod Anantharam, Cory Andrew Henson, Amit P. Sheth

Kno.e.sis Publications

Trust relationships occur naturally in many diverse contexts such as collaborative systems, e-commerce, interpersonal interactions, social networks, semantic sensor web, etc. As collaborating agents providing content and services become increasingly removed from the agents that consume them, the issue of robust trust inference and update become critical. There is a need to find online substitutes for traditional (direct or face-to-face) cues to derive measures of trust, and create efficient and secure system for managing trust, to support decision-making. Unfortunately, there is neither a universal notion of trust that is applicable to all domains nor a clear explication of its semantics …

Spatial Queries In Wireless Broadcast Environments [Keynote Speech], Kyriakos Mouratidis

Research Collection School Of Computing and Information Systems

Wireless data broadcasting is a promising technique for information dissemination that exploits the computational capabilities of mobile devices, in order to enhance the scalability of the system. Under this environment, the data are continuously broadcast by the server, interleaved with some indexing information for query processing. Clients may tune in the broadcast channel and process their queries locally without contacting the server. In this paper we focus on spatial queries in particular. First, we review existing methods on this topic. Next, taking shortest path computation as an example, we showcase technical challenges arising in this processing model and describe techniques …

A Software Framework For Augmentative And Alternative Communication, Adam Loup

LSU New Orleans Theses and Dissertations

By combining context awareness and analytical based relevance computing software, the proposed Augmentative and Alternative Communication (AAC) framework aims provide a foundation to create communication systems to dramatically increase the words available to AAC users. The framework will allow the lexicon available to the user to be dynamically updated by varying sources and to promote words based on contextual relevance. This level of customization enables the development of highly customizable AAC devices that evolve with use to become more personal while also broadening the expressiveness of the user. In order to maximize the efficient creation of conversation for AAC users, …

Extending Description Logic Rules, David Carral Martinez, Pascal Hitzler

Computer Science and Engineering Faculty Publications

Description Logics – the logics underpinning the Web Ontology Language OWL – and rules are currently the most prominent paradigms used for modeling knowledge for the Semantic Web. While both of these approaches are based on classical logic, the paradigms also differ significantly, so that naive combinations result in undesirable properties such as undecidability. Recent work has shown that many rules can in fact be expressed in OWL. In this paper we extend this work to include some types of rules previously excluded. We formally define a set of first order logic rules, C-Rules, which can be expressed within OWL …

Dynamic Data Extraction And Data Visualization With Application To The Kentucky Mesonet, Anoop Rao Paidipally

Masters Theses & Specialist Projects

There is a need to integrate large-scale database, high-performance computing engines and geographical information system technologies into a user-friendly web interface as a platform for data visualization and customized statistical analysis. We present some concepts and design ideas regarding dynamic data storage and extraction by making use of open-source computing and mapping technologies. We implemented our methods to the Kentucky Mesonet automated weather mapping workflow. The main components of the work flow includes a web based interface, a robust database and computing infrastructure designed for both general users and power users such as modelers and researchers.

Ensemble Of Feature Selection Techniques For High Dimensional Data, Sri Harsha Vege

Masters Theses & Specialist Projects

Data mining involves the use of data analysis tools to discover previously unknown, valid patterns and relationships from large amounts of data stored in databases, data warehouses, or other information repositories. Feature selection is an important preprocessing step of data mining that helps increase the predictive performance of a model. The main aim of feature selection is to choose a subset of features with high predictive information and eliminate irrelevant features with little or no predictive information. Using a single feature selection technique may generate local optima.

In this thesis we propose an ensemble approach for feature selection, where multiple …

Organizational Search In Email Systems, Sruthi Bhushan Pitla

Masters Theses & Specialist Projects

The storage space for emails has been increasing at a rapid pace day by day. Email systems still serve as very important data repositories for many users to store different kinds of information which they use in their daily activities. Due to the rapidly increasing volume of email data, there is a need to maintain the data in a most efficient way. It is also very important to provide intuitive and flexible search utilities to provide better access to the information in the email repositories, especially in an enterprise or organizational setting. In order to implement the functionality, we are …

Towards Self-Emancipation In Ict For Development Research: Narratives About Respect, Traditional Leadership And Building Networks Of Friendships In Rural South Africa, Kirstin Krauss

The African Journal of Information Systems

In this paper, the author contends that if the outsider-researcher involved in Information and Communication Technology for Development really wants to make a difference and honestly address the emancipatory interests of the developing community, social transformation will have to occur on both sides of the “development divide.” This statement implies both an understanding of the researcher’s own ethnocentrism, prejudice, assumptions and inabilities as well as local concerns, needs, expectations and realities. Using critical social theory as a position of inquiry and learning from the enculturation phases of critical ethnographic fieldwork in a deep rural part of South Africa, the paper …

Discontinuities And Best Practices In Virtual Research Collaboration, Vipin Arora, Deepak Khazanchi, Bjørn Erik Munkvold, Dawn Owens, Karen Stendal, Alvin Tarrell, Adeola Wale-Kolade, Sofi Westin, Ilze Zigurs

Information Systems and Quantitative Analysis Faculty Proceedings & Presentations

Research collaboration has become increasingly global, as collaboration technologies continue to advance and as research problems become more interdisciplinary and global. Virtual research teams have processes and challenges that are unique from a typical virtual team, and we need a better understanding of how such teams can utilize virtual research environments to their advantage. We examine this question from a review of the relevant literature and an analysis of experiences and reflections from a doctoral seminar that studied and experienced the process of virtual research collaboration.

Insider Threat Mitigation Models Based On Thresholds And Dependencies, Harini Ragavan

Graduate Theses and Dissertations

Insider threat causes great damage to data in any organization and is considered a serious issue. In spite of the presence of threat prevention mechanisms, sophisticated insiders still continue to attack a database with new techniques. One such technique which remains an advantage for insiders to attack databases is the dependency relationship among data items. This thesis investigates the ways by which an authorized insider detects dependencies in order to perform malicious write operations. The goal is to monitor malicious write operations performed by an insider by taking advantage of dependencies. A term called `threshold' is associated with every data …

Pamr: Passive-Aggressive Mean Reversion Strategy For Portfolio Selection, Bin Li, Peilin Zhao, Steven C. H. Hoi, Vivekanand Gopalkrishnan

Research Collection School Of Computing and Information Systems

This project proposes a novel online portfolio selection strategy named ``Passive Aggressive Mean Reversion" (PAMR). Unlike traditional trend following approaches, the proposed approach relies upon the mean reversion relation of financial markets. Equipped with online passive aggressive learning technique from machine learning, the proposed portfolio selection strategy can effectively exploit the mean reversion property of markets. By analyzing PAMR's update scheme, we find that it nicely trades off between portfolio return and volatility risk and reflects the mean reversion trading principle. We also present several variants of PAMR algorithm, including a mixture algorithm which mixes PAMR and other strategies. We …

Method And Apparatus For Rapid Identification Of Column Heterogeneity, Bing Tian Dai, Nikolaos Koudas, Beng Chin Ooi, Divesh Srivastava, Suresh Venkatasubranmanian

Research Collection School Of Computing and Information Systems

A method and apparatus for rapid identification of column heterogeneity in databases are disclosed. For example, the method receives data associated with a column in a database. The method computes a cluster entropy for the data as a measure of data heterogeneity and then determines whether said data is heterogeneous in accordance with the cluster entropy.

Spatial Queries In Wireless Broadcast Environments [Keynote Speech], Kyriakos Mouratidis

Research Collection School Of Computing and Information Systems

Wireless data broadcasting is a promising technique for information dissemination that exploits the computational capabilities of mobile devices, in order to enhance the scalability of the system. Under this environment, the data are continuously broadcast by the server, interleaved with some indexing information for query processing. Clients may tune in the broadcast channel and process their queries locally without contacting the server. In this paper we focus on spatial queries in particular. First, we review existing methods on this topic. Next, taking shortest path computation as an example, we showcase technical challenges arising in this processing model and describe techniques …

Organizing User Search Histories, Heasoo Hwang, Hady W. Lauw, Lise Getoor, Alexandros Ntoulas

Research Collection School Of Computing and Information Systems

Users are increasingly pursuing complex task-oriented goals on the web, such as making travel arrangements, managing finances, or planning purchases. To this end, they usually break down the tasks into a few codependent steps and issue multiple queries around these steps repeatedly over long periods of time. To better support users in their long-term information quests on the web, search engines keep track of their queries and clicks while searching online. In this paper, we study the problem of organizing a user's historical queries into groups in a dynamic and automated fashion. Automatically identifying query groups is helpful for a …

Spalendar: Visualizing A Group's Calendar Events Over A Geographic Space On A Public Display, Chen Xiang, Sebastian Boring, Sheelagh Carpendale, Anthony Tang, Saul Greenberg

Research Collection School Of Computing and Information Systems

Portable paper calendars (i.e., day planners and organizers) have greatly influenced the design of group electronic calendars. Both use time units (hours/days/weeks/etc.) to organize visuals, with useful information (e.g., event types, locations, attendees) usually presented as - perhaps abbreviated or even hidden - text fields within those time units. The problem is that, for a group, this visual sorting of individual events into time buckets conveys only limited information about the social network of people. For example, people’s whereabouts cannot be read ‘at a glance’ but require examining the text. Our goal is to explore an alternate visualization that can …

Design And Construction Of An Entity Resolution System That Supports Entity Identity Information Management And Asserted Resolution, Eric D. Nelson

Theses and Dissertations

This work describes the design and construction of an open source, entity resolution system that enables users to assign and maintain persistent identifiers for master data items. Two key features of this system that are not available in current ER systems and that make persistent identification possible are (1) The capture and management of entity identity information (2) Support for user-directed asserted resolution to complement automated direct matching and transitive closure Another important feature of the design is that the system can be easily configured at run-time into any one of four types of entity resolution architectures including * Traditional …

User Expectations Of Library Genealogy Databases V. What They Actually Get, Rosemary L. Meszaros, Katherine Pennavaria

DLPS Faculty Publications

An analysis and comparison of two genealogical databases: Ancestry.com and Heritagequest.com.

Asynchronous Ultrasonic Trilateration For Indoor Positioning Of Mobile Phones, Viacheslav Filonenko, Charlie Cullen, James Carswell

Conference papers

In this paper we discuss how the innate ability of mobile phone speakers to produce ultrasound can be used for accurate indoor positioning. The frequencies in question are in a range between 20 and 22 KHz, which is high enough to be inaudible by humans but still low enough to be generated by today’s mobile phone sound hardware. Our tests indicate that it is possible to generate the given range of frequencies without significant distortions, provided the signal volume is not turned excessively high. In this paper we present and evaluate the accuracy of our asynchronous trilateration method (Lok8) for …

Effects Of Variations In 3d Spatial Search Techniques On Mobile Query Speed Vs Accuracy, Junjun Yin, James Carswell

Conference papers

This paper presents three Spatial Search Algorithms for determiningthe three dimensional visibility shape (threat dome) at a user’s current locationin a built environment. Users then utilize this 3D shape as their query“window” to retrieve information on only those objects visible within a spatialdatabase. Visibility shape searching addresses the information overloadproblem by providing “Hidden Query Removal” functionality for mobile LBS.This functionality will be especially useful in the Web 4.0 era when trillions ofmicro-sensors become available for query through standard IP access.

Access Controls In Relational Databases, Rebekah Broome

Senior Seminars

There are many companies of all sizes that use databases to keep their data organized and easy to access. Databases have multiple parts, such as domains and constraints, Database Management System, and Metadata that make them unique. Not only does this paper cover the elements of a database but more specifically the elements of relational databases. This paper will go over the definition of relation databases, what makes this kind of database unique with the relation between tables, and how Standard Query Language is used by relational database. Then the paper will move on to the access controls that are …

Evaluating The Effect Of Smart Parking Technology On Campus Parking System Efficiency Using Discrete Event Simulation, Glenn Phillip Surpris

Doctoral Dissertations and Master's Theses

This study was conducted to investigate the effect of smart parking systems (SPS) on parking search times (PST) in large parking lots. SPSs are systems that disseminate real-time parking spot availability to drivers searching for parking. The literature review revealed discrete event simulation (DES) to be a suitable tool for studying the dynamic behavior in parking lots. The parking lot selected for data collection was a university parking lot with 234 spaces. The data collected included arrival rates, departure rates, the geometric properties of the parking lot, preferred parking search strategies, and driving speeds. Arena 13.9, by Rockwell Automation, Inc, …

Structural Analysis In Multi-Relational Social Networks, Bing Tian Dai, Freddy Chong Tat Chua, Ee-Peng Lim

Research Collection School Of Computing and Information Systems

Modern social networks often consist of multiple relationsamong individuals. Understanding the structureof such multi-relational network is essential. In sociology,one way of structural analysis is to identify differentpositions and roles using blockmodels. In thispaper, we generalize stochastic blockmodels to GeneralizedStochastic Blockmodels (GSBM) for performing positionaland role analysis on multi-relational networks.Our GSBM generalizes many different kinds of MultivariateProbability Distribution Function (MVPDF) tomodel different kinds of multi-relational networks. Inparticular, we propose to use multivariate Poisson distributionfor multi-relational social networks. Our experimentsshow that GSBM is able to identify the structuresfor both synthetic and real world network data.These structures can further be used for predicting …

Detecting Extreme Rank Anomalous Collections, Hanbo Dai, Feida Zhu, Ee-Peng Lim, Hwee Hwa Pang

Research Collection School Of Computing and Information Systems

Anomaly or outlier detection has a wide range of applications, including fraud and spam detection. Most existing studies focus on detecting point anomalies, i.e., individual, isolated entities. However, there is an increasing number of applications in which anomalies do not occur individually, but in small collections. Unlike the majority, entities in an anomalous collection tend to share certain extreme behavioral traits. The knowledge essential in understanding why and how the set of entities becomes outliers would only be revealed by examining at the collection level. A good example is web spammers adopting common spamming techniques. To discover this kind of …

Mining Social Dependencies In Dynamic Interaction Networks, Freddy Chong-Tat Chua, Hady W. Lauw, Ee Peng Lim

Research Collection School Of Computing and Information Systems

User-to-user interactions have become ubiquitous in Web 2.0. Users exchange emails, post on newsgroups, tag web pages, co-author papers, etc. Through these interactions, users co-produce or co-adopt content items (e.g., words in emails, tags in social bookmarking sites). We model such dynamic interactions as a user interaction network, which relates users, interactions, and content items over time. After some interactions, a user may produce content that is more similar to those produced by other users previously. We term this effect social dependency, and we seek to mine from such networks the degree to which a user may be socially dependent …