Engineering Commons^™

Anonymous Query Processing In Road Networks, Kyriakos Mouratidis, Man Lung Yiu

Kyriakos MOURATIDIS

The increasing availability of location-aware mobile devices has given rise to a flurry of location-based services (LBSs). Due to the nature of spatial queries, an LBS needs the user position in order to process her requests. On the other hand, revealing exact user locations to a (potentially untrusted) LBS may pinpoint their identities and breach their privacy. To address this issue, spatial anonymity techniques obfuscate user locations, forwarding to the LBS a sufficiently large region instead. Existing methods explicitly target processing in the euclidean space and do not apply when proximity to the users is defined according to network distance …

On-Line Discovery Of Hot Motion Paths, Dimitris Sacharidis, Kostas Patroumpas, Manolis Terrovitis, Verena Kantere, Michalis Potamias, Kyriakos Mouratidis, Timos Sellis

Kyriakos MOURATIDIS

We consider an environment of numerous moving objects, equipped with location-sensing devices and capable of communicating with a central coordinator. In this setting, we investigate the problem of maintaining hot motion paths, i.e., routes frequently followed by multiple objects over the recent past. Motion paths approximate portions of objects' movement within a tolerance margin that depends on the uncertainty inherent in positional measurements. Discovery of hot motion paths is important to applications requiring classification/profiling based on monitored movement patterns, such as targeted advertising, resource allocation, etc. To achieve this goal, we delegate part of the path extraction process to objects, …

Continuous Monitoring Of Spatial Queries In Wireless Broadcast Environments, Kyriakos Mouratidis, Spiridon Bakiras, Dimitris Papadias

Kyriakos MOURATIDIS

Wireless data broadcast is a promising technique for information dissemination that leverages the computational capabilities of the 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 then tune in the broadcast channel and process their queries locally without contacting the server. Previous work on spatial query processing for wireless broadcast systems has only considered snapshot queries over static data. In this paper, we propose an air indexing framework that 1) outperforms the existing (i.e., snapshot) techniques in …

Optimal Matching Between Spatial Datasets Under Capacity Constraints, Hou U Leong, Kyriakos Mouratidis, Man Lung Yiu, Nikos Mamoulis

Kyriakos MOURATIDIS

Consider a set of customers (e.g., WiFi receivers) and a set of service providers (e.g., wireless access points), where each provider has a capacity and the quality of service offered to its customers is anti-proportional to their distance. The capacity constrained assignment (CCA) is a matching between the two sets such that (i) each customer is assigned to at most one provider, (ii) every provider serves no more customers than its capacity, (iii) the maximum possible number of customers are served, and (iv) the sum of Euclidean distances within the assigned provider-customer pairs is minimized. Although max-flow algorithms are applicable …

Continuous Spatial Assignment Of Moving Users, Leong Hou U, Kyriakos Mouratidis, Nikos Mamoulis

Kyriakos MOURATIDIS

Consider a set of servers and a set of users, where each server has a coverage region (i.e., an area of service) and a capacity (i.e., a maximum number of users it can serve). Our task is to assign every user to one server subject to the coverage and capacity constraints. To offer the highest quality of service, we wish to minimize the average distance between users and their assigned server. This is an instance of a well-studied problem in operations research, termed optimal assignment. Even though there exist several solutions for the static case (where user locations are fixed), …

Shortest Path Computation On Air Indexes, Georgios Kellaris, Kyriakos Mouratidis

Kyriakos MOURATIDIS

Shortest path computation is one of the most common queries in location-based services that involve transportation net- works. Motivated by scalability challenges faced in the mo- bile network industry, we propose adopting the wireless broad- cast model for such location-dependent applications. In this model the data are continuously transmitted on the air, while clients listen to the broadcast and process their queries locally. Although spatial problems have been considered in this environment, there exists no study on shortest path queries in road networks. We develop the rst framework to compute shortest paths on the air, and demonstrate the practicality and …

Preference Queries In Large Multi-Cost Transportation Networks, Kyriakos Mouratidis, Yimin Lin, Man Lung Yiu

Kyriakos MOURATIDIS

Research on spatial network databases has so far considered that there is a single cost value associated with each road segment of the network. In most real-world situations, however, there may exist multiple cost types involved in transportation decision making. For example, the different costs of a road segment could be its Euclidean length, the driving time, the walking time, possible toll fee, etc. The relative significance of these cost types may vary from user to user. In this paper we consider such multi-cost transportation networks (MCN), where each edge (road segment) is associated with multiple cost values. We formulate …

Network Security Toolkit Including Heuristic Solutions For Trust System Placement And Network Obfuscation, Gabriel H. Greve

Theses and Dissertations

For Part I, a supervisory control and data acquisition (SCADA) network consists of a group stations and substations in a portion of the power grid. The use of Internet technology in SCADA communications as well as other factors has caused vulnerabilities. One idea to help mitigate this risk is to strategically place trust nodes to compartmentalize and secure the SCADA systems without disturbing its finely honed processes. The trust nodes combine firewall and intrusion detection technology to provide more secure communication. An optimal solution to this problem has already been developed using a mixed-integer linear programming model. Because the problem …

A Comprehensive Analysis Of Lte Physical Layer, Fahimeh Rezaei

Computer and Electronics Engineering: Dissertations, Theses, and Student Research

The 3rd Generation Partnership Project (3GPP) introduced Long Term Evolution (LTE) as the 3rd generation of mobile communication standards. LTE Release 8 describes a mobile communication standard which supports up to 300 Mbps of data transmission in downlink using the OFDM scheme as well as up to 75 Mbps throughput for uplink using the SC-FDMA modulation. In this thesis, an in-depth study of LTE performance based on Release 8 is conducted for uplink and downlink under different scenarios. The main objective of this study is to investigate a comprehensive analysis of physical layer throughput of LTE Release8 based on standard …

Cross-Layer Optimized Wireless Multimedia Networking, Dalei Wu

Computer and Electronics Engineering: Dissertations, Theses, and Student Research

Multimedia communications, especially real-time video communications, is expected to be the major application of the next-generation wireless networks. However, bringing delay-sensitive and loss-tolerant multimedia services based on the current wireless Internet is a very challenging task. In this dissertation, we address cross-layer optimized wireless multimedia networking from both theoretical and practical perspectives. In the first part of the dissertation, we propose cross-layer optimization frameworks for real-time video communications over wireless networks, where the expected received video quality is adopted as the objective function. With the user-centric objective function, we first study content-aware video communications in single-hop wireless networks by exploring …

Sports-Tool, Bryant Ung

Computer Science and Software Engineering

Creating events and finding people to play sports is a hard thing to do. The solution to this problem is to provide a web based interactive site that allows people to create and join different type of events and interact with each other by creating teams.

Security@Web: Teaching Security With Alignment In Trust On The Web (Final Report), Li-Chiou Chen, Mary Long

Cornerstone 3 Reports : Interdisciplinary Informatics

No abstract provided.

Use Of Mobile Phone Computing For Development Of Student 21st Century Skills, Susan M. Merritt, R. Lara Lee

Cornerstone 2 Reports : Community Outreach and Empowerment Through Service Learning and Volunteerism

Mobile phone computing enables immediate capture and transfer of data, images, notes and experiences from the field to a repository where retrieval, analysis, edits, aggregation, and further development are possible. Immediate findings and later results can be shared on the Web with local and global communities, and development of integrated service learning projects in concert with underserved communities is possible using this mode of information gathering and sharing.

Mobile phone computing incorporates moments when participants build tomorrow's skills while addressing today's learning goals. Use of digital tools and supporting resources bring real world problems into focus. Mobile phone computing enables …

Dynamic Distributed Programming And Applications To Swap Edge Problem, Feven Z. Andemeskel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Link failure is a common reason for disruption in communication networks. If communication between processes of a weighted distributed network is maintained by a spanning tree T, and if one edge e of T fails, communication can be restored by finding a new spanning tree, T’. If the network is 2-edge connected, T’ can always be constructed by replacing e by a single edge, e’, of the network. We refer to e’ as a swap edge of e.

The best swap edge problem is to find the best choice of e’, that is, that e which causes the new spanning …

Self-Stabilizing Leader Election In Dynamic Networks, Hema Piniganti

UNLV Theses, Dissertations, Professional Papers, and Capstones

The leader election problem is one of the fundamental problems in distributed computing. It has applications in almost every domain. In dynamic networks, topology is expected to change frequently. An algorithm A is self-stabilizing if, starting from a completely arbitrary configuration, the network will eventually reach a legitimate configuration.

Note that any self-stabilizing algorithm for the leader election problem is also an algorithm for the dynamic leader election problem, since when the topology of the network changes, we can consider that the algorithm is starting over again from an arbitrary state. There are a number of such algorithms in the …

Self-Stabilizing Group Membership Protocol, Mahesh Subedi

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this thesis, we consider the problem of partitioning a network into groups of bounded diameter.

Given a network of processes X and a constant D, the group partition problem is the problem of finding a D-partition of X, that is, a partition of X into disjoint connected subgraphs, which we call groups, each of diameter no greater than D. The minimal group partition problem is to find a D-partition {G1, ... Gm} of X such that no two groups can be combined; that is, for any Gi and Gj, where i ≠ j, either Gi U Gj is disconnected …

Product Life Cycle Theory And The Maturation Of The Internet, Christopher S. Yoo

All Faculty Scholarship

Much of the recent debate over Internet policy has focused on the permissibility of business practices that are becoming increasingly common, such as new forms of network management, prioritization, pricing, and strategic partnerships. This Essay analyzes these developments through the lens of the management literature on the product life cycle, dominant designs, technological trajectories and design hierarchies, and the role of complementary assets in determining industry structure. This analysis suggests that many of these business practices may represent nothing more than a reflection of how the nature of competition changes as industries mature. This in turn suggests that network neutrality …

The Kerf Toolkit For Intrusion Analysis, Javed A. Aslam, Sergey Bratus, David Kotz, Ron Peterson, Brett Tofel, Daniela Rus

Javed A. Aslam

To aid system administrators with post-attack intrusion analysis, the Kerf toolkit provides an integrated front end and powerful correlation and data-representation tools, all in one package.

On Iterative Decoding Of Two-Level Superposition Codes For Cooperative Broadcasting Based On Qpsk And 4-Pam Constellations, Robert H. Morelos-Zaragoza

Robert Henry Morelos-Zaragoza

This paper considers iterative decoding of two-level superposition codes used in cooperative broadcasting over wireless networks. The coding scheme consists of two low-density parity-check (LDPC) codes combined using Plotkin’s |u|u+v|-construction and provides two levels of error protection.

Assessing Value Creation And Value Capture In Digital Business Ecosystems, Ravi S. Sharma, Francis Pereira, Narayan Ramasubbu, Margaret Tan, F. Ted Tschang

Research Collection Lee Kong Chian School of Business

Interest in business modeling of technology enterprises – the activity of designing the architecture for revenues, costs, products and/or services delivery and the overall value of an enterprise – has risen to prominence with the global crossing of the Internet chasm. However, as several studies have pointed out (c.f., Osterwalder, Pigneur & Tucci, 2005; Teece 2010; Zott & Amit, 2010), the investigations of business models and their fit with the strategy of an enterprise, have received little scholarly attention. In this article we formulate a framework, called ADVISOR, for modeling the business strategies of enterprises in the Interactive Digital Media …

Design And Implementation Of User Level Socket Application Programming Interface With Socket Splitting And Mediation, Scott Walter Holzer

Master's Theses

Over the past few decades, the size and scope of the Internet has grown exponentially. In order to maintain support for legacy clients, new applications and services have been limited by dependence on traditional sockets and TCP, which provide no support for modifying endpoints after connection setup. This forces applications to implement their own logic to reroute communications to take advantage of composable services or handle failover. Some solutions have added socket operations that allow for endpoints to be redirected on the fly, but these have been limited in scope to handling failover and load balancing.

We present two new …

Software Engineering Issues For Mobile Application Development, Tony Wasserman

Tony Wasserman

This paper provides an overview of important software engineering research issues related to the development of applications that run on mobile devices. Among the topics are development processes, tools, user interface design, application portability, quality, and security.

Public Consultations On Net Neutrality 2010: Usa, Eu And France, Sulan Wong, Julio Rojas Mora, Eitan Altman

Julio Rojas-Mora

The evolution of the Internet has come to a point where almost at the same time, governments all around the world feel the need for legislation to regulate the use of the Internet. In preparing the legislation, consultations were called by various governments or by the corresponding regulation bodies. We describe in this paper the various consultations as well as the background related to the Net Neutrality question in each case. Rather than describing the answers to each consultation, which are available and which have already been analyzed, we focus on comparing the consultations and the statistical figures related to …

Reputation-Based Internet Protocol Security: A Multilayer Security Framework For Mobil Ad Hoc Networks, Timothy H. Lacey

Theses and Dissertations

This research effort examines the theory, application, and results for a Reputation-based Internet Protocol Security (RIPSec) framework that provides security for an ad-hoc network operating in a hostile environment. In RIPSec, protection from external threats is provided in the form of encrypted communication links and encryption-wrapped nodes while internal threats are mitigated by behavior grading that assigns reputations to nodes based on their demonstrated participation in the routing process. Network availability is provided by behavior grading and round-robin multipath routing. If a node behaves faithfully, it earns a positive reputation over time. If a node misbehaves (for any number of …

Improving The Quality Of Service And Security Of Military Networks With A Network Tasking Order Process, Matthew D. Compton

Theses and Dissertations

This research presents a Network Tasking Order process that collects mission plans, network capabilities, and historical records to build a Network Tasking Order (NTO). The NTO document directs the form and usage of the network, much like an Air Tasking Order (ATO) directs the usage of air power. The NTO process is fleshed out with the content and format of the NTO given herein for the first time. Tools such as topology control algorithms are then shown through simulation to improve the quality of service of the network by finding favorable ways to connect the assets identified during the NTO …

Applying Image Matching To Video Analysis, Adam J. Behring

Theses and Dissertations

Dealing with the volume of multimedia collected on a daily basis for intelligence gathering and digital forensics investigations requires significant manual analysis. A component of this problem is that a video may be reanalyzed that has already been analyzed. Identifying duplicate video sequences is difficult due to differences in videos of varying quality and size. This research uses a kd-tree structure to increase image matching speed. Keypoints are generated and added to a kd-tree of a large dimensionality (128 dimensions). All of the keypoints for the set of images are used to construct a global kd-tree, which allows nearest neighbor …

Hijacking User Uploads To Online Persistent Data Repositories For Covert Data Exfiltration, Curtis P. Barnard

Theses and Dissertations

As malware has evolved over the years, it has gone from harmless programs that copy themselves into other executables to modern day botnets that perform bank fraud and identity theft. Modern malware often has a need to communicate back to the author, or other machines that are also infected. Several techniques for transmitting this data covertly have been developed over the years which vary significantly in their level of sophistication. This research creates a new covert channel technique for stealing information from a network by piggybacking on user-generated network traffic. Specifically, steganography drop boxes and passive covert channels are merged …

A Cross-Layer Modification To The Dsr Routing Protocol In Wireless Mesh Networks, Mustafa Ramadhan

Doctoral

A cross-layer modification to the DSR routing protocol that finds high throughput paths in WMNs has been introduced in this work. The Access Efficiency Factor (AEF) has been introduced in this modification as a local congestion avoidance metric for the DSR routing mechanism as an alternative to the hop count (Hc) metric. In this modification, the selected path is identified by finding a path with the highest minimum AEF (max_min_AEF) value. The basis of this study is to compare the performance of the Hc and max_min_AEF as routing metrics for the DSR protocol in WMNs using the OPNET modeler. Performance …

Beyond Ning: Rolling Your Own Social Network, Aaron Sumner

SIDLIT Conference

Ning has recently announced plans to discontinue its free service, requiring network creators to pay for service or leave Ning altogether. In this session we'll look at how this decision affects educational users of Ning, as well as alternative, DIY social networking software packages such as Elgg, Buddypress, and Community Engine.

Is The Internet A Maturing Market? If So, What Does That Imply?, Christopher S. Yoo

All Faculty Scholarship

Network providers are experimenting with a variety of new business arrangements. Some are offering specialized services the guarantee higher levels of quality of service those willing to pay for it. Others are entering into strategic partnerships that allocate more bandwidth to certain sources. Interestingly, a management literature exists suggesting that both developments may simply reflect the ways that the nature of competition and innovation can be expected as markets mature. The real question is not if the nature of competition and innovation will change, but rather when and how. This theory also suggests that policymakers should be careful not to …