Computer Sciences Commons^™

Dynamically-Optimized Context In Recommender Systems, Ghim-Eng Yap, Ah-Hwee Tan, Hwee-Hwa Pang

Research Collection School Of Computing and Information Systems

Traditional approaches to recommender systems have not taken into account situational information when making recommendations, and this seriously limits the relevance of the results. This paper advocates context-awareness as a promising approach to enhance the performance of recommenders, and introduces a mechanism to realize this approach. We present a framework that separates the contextual concerns from the actual recommendation module, so that contexts can be readily shared across applications. More importantly, we devise a learning algorithm to dynamically identify the optimal set of contexts for a specific recommendation task and user. An extensive series of experiments has validated that our …

Ensight, Jonathan Hefner

Honors Capstones

No abstract provided.

Improving The Performance Of Internet Data Transport, Anshul Kantawala, Jonathan S. Turner

All Computer Science and Engineering Research

With the explosion of the World Wide Web, the Internet infrastructure faces new challenges in providing high performance for data traffic. First, it must be able to pro-vide a fair-share of congested link bandwidth to every flow. Second, since web traffic is inherently interactive, it must minimize the delay for data transfer. Recent studies have shown that queue management algorithms such as Tail Drop, RED and Blue are deficient in providing high throughput, low delay paths for a data flow. Two major shortcomings of the current algorithms are: they allow TCP flows to get synchronized and thus require large buffers …

Information Dissemination Via Wireless Broadcast, Baihua Zheng, Dik Lun Lee

Research Collection School Of Computing and Information Systems

Unrestricted mobility adds a new dimension to data access methodology--- one that must be addressed before true ubiquity can be realized.

Dynamically Optimized Context In Recommender Systems, Ghim-Eng Yap, Ah-Hwee Tan, Hwee Hwa Pang

Research Collection School Of Computing and Information Systems

Traditional approaches to recommender systems have not taken into account situational information when making recommendations, and this seriously limits the relevance of the results. This paper advocates context-awareness as a promising approach to enhance the performance of recommenders, and introduces a mechanism to realize this approach. We present a framework that separates the contextual concerns from the actual recommendation module, so that contexts can be readily shared across applications. More importantly, we devise a learning algorithm to dynamically identify the optimal set of contexts for a specific recommendation task and user. An extensive series of experiments has validated that our …

Minimum Energy Reliable Paths Using Unreliable Wireless Links, Qunfeng Dong, Suman Banerjee, Micah Adler, Archan Misra

Research Collection School Of Computing and Information Systems

We address the problem of energy-efficient reliable wireless communication in the presence of unreliable or lossy wireless link layers in multi-hop wireless networks. Prior work [1] has provided an optimal energy efficient solution to this problem for the case where link layers implement perfect reliability. However, a more common scenario --- a link layer that is not perfectly reliable, was left as an open problem. In this paper we first present two centralized algorithms, BAMER and GAMER, that optimally solve the minimum energy reliable communication problem in presence of unreliable links. Subsequently we present a distributed algorithm, DAMER, that approximates …

Event-Driven Document Selection For Terrorism, Zhen Sun, Ee Peng Lim, Kuiyu Chang, Teng-Kwee Ong, Rohan Kumar Gunaratna

Research Collection School Of Computing and Information Systems

In this paper, we examine the task of extracting information about terrorism related events hidden in a large document collection. The task assumes that a terrorism related event can be described by a set of entity and relation instances. To reduce the amount of time and efforts in extracting these event related instances, one should ideally perform the task on the relevant documents only. We have therefore proposed some document selection strategies based on information extraction (IE) patterns. Each strategy attempts to select one document at a time such that the gain of event related instance information is maximized. Our …

Leveraging Global Resources: A Distributed Process Maturity Framework For Software Product Development, Narayan Ramasubbu, M. S. Krishnan, Prasad Kompalli

Research Collection School Of Computing and Information Systems

Distributed software development is pervasive in the software industry today as companies vie to leverage global resources. However, popular quality and process frameworks don?t specifically address the key processes needed for managing distributed software development. This practitioner-oriented, evolutionary process maturity framework for globally distributed software development features 24 new key process areas essential for managing distributed software product development and for continuously improving product management capabilities. An assessment survey helps practitioners implement the framework. In this article, the authors detail the framework and assessment survey, as well as report their experiences implementing the framework at a leading global firm. The …

Protecting Group Dynamic Information In Large Scale Multicast Groups, Yongdong Wu, Tieyan Li, Robert H. Deng

Research Collection School Of Computing and Information Systems

Existing key management schemes can secure group communication efficiently, but are failed on protecting the Group Dynamic Information (GDI) that may undermine group privacy. Recently, Sun et al. proposed a scheme to hide the GDI with batch updating and phantom members inserting so that an adversary is not able to estimate the number of group members. In this paper, we first point out that their scheme is only applicable in departure-only group communication instead of the common conference groups. Secondly, we introduce our method of estimating the group size at a higher confidence level given a prior departure probability. Further, …

A New Architecture For User Authentication And Key Exchange Using Password For Federated Enterprises, Yanjiang Yang, Feng Bao, Robert H. Deng

Research Collection School Of Computing and Information Systems

The rapid rise of federated enterprises entails a new way of trust management by the fact that an enterprise can account for partial trust of its affiliating organizations. On the other hand, password has historically been used as a main means for user authentication because of operational simplicity. We are thus motivated to explore the use of short password for user authentication and key exchange in the context of federated enterprises. Exploiting the special structure of a federated enterprise, our proposed new architecture comprises an external server managed by each affiliating organization and a central server managed by the enterprise …

Secure Human Communications Based On Biometrics Signals, Yongdong Wu, Feng Bao, Robert H. Deng

Research Collection School Of Computing and Information Systems

User authentication is the first and probably the most challenging step in achieving secure person-to-person communications. Most of the existing authentication schemes require communicating parties either share a secret/password or know each other's public key. In this paper we suggest a novel user authentication scheme that is easy to use and overcomes the requirements of sharing password or public keys. Our scheme allows two human users to perform mutual authentication and have secure communications over an open channel by exchanging biometrics signals (e. g., voice or video signals). In addition to user authentication, our scheme establishes a secret session key …

Tosa: A Near-Optimal Scheduling Algorithm For Multi-Channel Data Broadcast, Baihua Zheng, Xia Xu, Xing Jin, Dik Lun Lee

Research Collection School Of Computing and Information Systems

Wireless broadcast is very suitable for delivering information to a large user population. In this paper, we concentrate on data allocation methods for multiple broadcast channels. To the best of our knowledge, this is the first allocation model that takes into the consideration of items' access frequencies, items' lengths. and bandwidth of different channels. We first derive the optimal average expected delay for multiple channels for the general case where data access frequencies, data sizes, and channel bandwidths can all be non-uniform. Second, we develop TOSA, a multi-channel allocation method that does not assume a uniform broadcast schedule for data …

Synthesizing E-Government Stage Models – A Meta-Synthesis Based On Meta-Ethnography Approach, Keng Siau, Y. Long

Research Collection School Of Computing and Information Systems

The growing interest in e-government raises the question of stages in e-government development. A few stage models for e-government have been proposed. Without a common e-government stage model, different research in e-government may be based on different stage models. This presents a difficulty in comparing and understanding different research results. In this research, we synthesize the existing e-government stage models so that there is a common frame of reference for researchers and practitioners in the area.

Live Data Views: Programming Pervasive Applications That Use “Timely” And “Dynamic” Data, Jay Black, Paul Castro, Archan Misra, Jerome White

Research Collection School Of Computing and Information Systems

In the absence of generic programming abstractions for dynamic data in most enterprise programming environments, individual applications treat data streams as a special case requiring custom programming. With the growing number of live data sources such as RSS feeds, messaging and presence servers, multimedia streams, and sensor data. a general-purpose client-server programming model is needed to easily incorporate live data into applications. In this paper, we present Live Data Views, a programming abstraction that represents live data as a time-windowed view over a set of data streams. Live Data Views allow applications to create and retrieve stateful abstractions of dynamic …

Mining Mobile Group Patterns: A Trajectory-Based Approach, San-Yih Hwang, Ying-Han Liu, Jeng-Kuen Chiu, Ee Peng Lim

Research Collection School Of Computing and Information Systems

In this paper, we present a group pattern mining approach to derive the grouping information of mobile device users based on a trajectory model. Group patterns of users are determined by distance threshold and minimum time duration. A trajectory model of user movement is adopted to save storage space and to cope with untracked or disconnected location data. To discover group patterns, we propose ATGP algorithm and TVG-growth that are derived from the Apriori and VG-growth algorithms respectively.

Relative Difference Sets In 2-Groups : A Group Cohomological Viewpoint, Brian Wyman

Honors Theses

No abstract provided.

Static Determination Of Allocation Rates To Support Real-Time Garbage Collection, Tobias Mann

All Computer Science and Engineering Research

While it is generally accepted that garbage-collected languages offer advantages over languages in which objects must be explicitly deallocated, real-time developers are leery of the adverse effects a garbage collector might have on real-time performance. Semiautomatic approaches based on regions have been proposed, but incorrect usage could cause unbounded storage leaks or program failure. Moreover, correct usage cannot be guaranteed at compile-time. Recently, real-time garbage collectors have been developed that provide a guaranteed fraction of the CPU to the application, and the correct operation of those collectors has been proven, subject only to the specification of certain statistics related to …

Generation Of Office Buildings In Large Scale Virtual Worlds, Michael Mcbryde

Computer Science Honors Theses

Virtual worlds are used in many different areas, from military training simulations to massive multiplayer online role-playing games. In the past, the sizes of these worlds was limited by the power of the computers that ran them as well as the man-hours needed to draw them. However, as computers have become more powerful, the limiting fctor has become the man-hours needed to manually draw every object in such a world. So there is now a need for large scale, traversable, dynamic, algorithmically generated virtual worlds. For these worlds to be realistic, cities need to be generated, and for these cities …

A Benchmark And Analysis Of Spatial Data Structures For Physical Simulations, Domingo Lara

Computer Science Honors Theses

Collision detection is an issue in physical simulations; without it simulations are inaccurate. Unfortunately, effective collision detection can require a significant amount of computational power. To reduce the number of computations and make the problem more tractable, computer scientists have used date structures to partition the system. This removes the need to have every single partical check for possible collisions with every other particle in the system; however, generic data structures typically do not work as well as specialized data structures, so this has led to the creation of multiple spatial data structures. Some spatial data structures and algorithms were …

Algorithmic Generation Of Cities Using Cellular Automata In A Dynamically Generated World, Eric Garza

Computer Science Honors Theses

The procedures and algorithms used to create a realistic city in a virtual world are outlined in this paper. The world is algorithmically created from a single random number. The terrain, water, and population of various races are created in real time as a viewer walks around the world. The world is created in various levels of detail; objects that are close to the viewer are fully generated in high detail, and objects further away from the viewer are not created. The locations of the cities are first based on the pre-existing world then on the set of tolerances of …

Ecological Niching In An Interactive Simulation, Ryan T. Webb

Honors Theses

Our goal is to create a simulation platform for the study of ecological niching that can be extended to suit the needs of biological research. Ecological niching and the accompanying evolutionary process of speciation are difficult to observe in situ, which makes them prime candidates for study via the methods of computer simulation. To this end, we have created an interactive, real-time ecosystem simulation based on the standard predator/prey interaction model, in which interacting populations of organisms exhibit swarming behavior. We hope to provide the basic simulation components necessary to bring about niching and speciation, that may be extended for …

Web Services To Semantic Web Processes: Investigating Synergy Between Practice And Research, Amit P. Sheth

Kno.e.sis Publications

No abstract provided.

Composable Timed Automata Models For Real-Time Embedded Systems Middleware, Venkita Subramonian, Christopher Gill, Cesar Sanchez, Henny Sipma

All Computer Science and Engineering Research

Middleware for distributed real-time embedded (DRE) systems has grown more and more complex in recent years, to address functional and temporal requirements of complex real-time applications. While current approaches for modeling middleware have eased the task of assembling, deploying and configuring middleware and applications, a more formal, fundamental and lower-level set of models is needed to be able to uncover subtle safety and timing errors introduced by interference between computations, particularly in the face of alternative concurrency strategies in the middleware layer. In this paper, we examine how formal models of lower-level middleware building blocks provide an appropriate level of …

Improving And Extending Behavioral Animation Through Machine Learning, Jonathan J. Dinerstein

Theses and Dissertations

Behavioral animation has become popular for creating virtual characters that are autonomous agents and thus self-animating. This is useful for lessening the workload of human animators, populating virtual environments with interactive agents, etc. Unfortunately, current behavioral animation techniques suffer from three key problems: (1) deliberative behavioral models (i.e., cognitive models) are slow to execute; (2) interactive virtual characters cannot adapt online due to interaction with a human user; (3) programming of behavioral models is a difficult and time-intensive process. This dissertation presents a collection of papers that seek to overcome each of these problems. Specifically, these issues are alleviated …

Interactive Image Filling-In, Teryl Lynne Arnold

Theses and Dissertations

Removing unwanted scratches or objects from an image in an undetectable manner is a technique that has been researched for its many useful and varied applications, such as removing scratches, defects, super-imposed text, or even entire objects from a scene. Currently there is a wide variety of algorithms that fill in unwanted regions, none of which incorporate user preferences into the structure completion process. By building a framework to incorporate user preferences into the filling-in process, user input can be utilized to more effectively fill in damaged regions in an image. User input can influence the filling-in process in a …

T-Spline Merging, Heather Ipson

Theses and Dissertations

Geometric models, such as for use in CAD/CAM or animation, are often constructed in a piece-wise fashion. Historically, these models have been made of NURBS surfaces. For various reasons it is problematic and often times mathematically impossible to combine several NURBS models into one continuous surface. The recent invention of a surface type called T-splines has made the combining of NURBS surfaces into a single continuous surface possible, but much of the mathematics has yet to be explored. This thesis explores the mathematics and algorithms necessary to merge multiple NURBS, T-spline, or T-NURCC surfaces into a single continuous surface. This …

Reconstructability Analysis And Log-Linear Modeling, Martin Zwick

Complex Systems Faculty Publications and Presentations

Reconstructability Analysis (RA) is a method developed within the systems community for analyzing nominal (or discretized) data. RA both overlaps and extends Log-Linear (LL) modeling, and the purpose of this talk is to introduce RA to researchers unfamiliar with it. Two aspects of RA will be focused on: (1) its use for exploratory, as opposed to confirmatory, modeling – searching for good models in a vast space of possible models, and (2) state-based RA – analyzing data not in terms of relations among variables but in terms of relations among specific states of variables. Examples of applications to social science …

The Tirac™ Development Toolkit: Technical Description, Russell Leighton, Lakshmi Vempati, Alan Davis, Mark Porczak, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

This report provides a technical description of the Toolkit for Information Representation and Agent Collaboration (TIRAC^™) software framework for the development of intelligent decision-support applications. An overview of the transformational forces that have precipitated the need for a development toolkit capable of supporting a distributed, information-centric software environment, and the objectives of TIRAC™ are contained in a companion CDM Technical Report (CDM-17-04) entitled: “The TIRAC^™ Development Toolkit: Purpose and Overview.”

TIRAC™ is an application development framework and toolkit for distributed decision-support systems incorporating software agents that collaborate with each other and human users to monitor changes (i.e., …

January: Search Based On Social Insect Behavior, Peter C. Lamborn

Theses and Dissertations

January is a group of interacting stateless model checkers. Each agent functions on a processor located on a super computer or a network of workstations (NOW). The agent's search pattern is a semi-random walk based on the behavior of the grey field slug (Agriolimax reticulatus), the house fly (Musca domestica), and the black ant (Lassius niger). The agents communicate to lessen the amount of duplicate work being done. Every algorithm has a memory threshold above which they search efficiently. This threshold varies not only by model but also by algorithm. Janaury's threshold is lower than the thresholds of other algorithms …

What A Mesh: Dependent Data Types For Correct Mesh Manipulation Algorithms, Joel R. Brandt

All Computer Science and Engineering Research

The Edinburgh Logical Framework (LF) has been proposed as a system for expressing inductively defined sets. I will present an inductive definition of the set of manifold meshes in LF. This definition takes into account the topological characteri-zation of meshes, namely their Euler Characteristic. I will then present a set of dependent data types based on this inductive def-inition. These data types are defined in a programming language based on LF. The language’s type checking guarantees that any typeable expression represents a correct manifold mesh. Furthermore, any mesh can be represented using these data types. Hence, the encoding is sound …