Digital Commons Network^™

An Analysis Of The Performance And Security Of J2sdk 1.4 Jsse Implementation Of Ssl/Tls, Danny R. Bias

Theses and Dissertations

The Java SSL/TLS package distributed with the J2SE 1.4.2 runtime is a Java implementation of the SSLv3 and TLSv1 protocols. Java-based web services and other systems deployed by the DoD will depend on this implementation to provide confidentiality, integrity, and authentication. Security and performance assessment of this implementation is critical given the proliferation of web services within DoD channels. This research assessed the performance of the J2SE 1.4.2 SSL and TLS implementations, paying particular attention to identifying performance limitations given a very secure configuration. The performance metrics of this research were CPU utilization, network bandwidth, memory, and maximum number of …

Intelligent Query Answering Through Rule Learning And Generalization, James M. Carsten

Theses and Dissertations

The Department of Defense (DoD) relies heavily on information systems to complete a myriad of tasks, from day-to-day personnel actions to mission critical imagery retrieval, intelligence analysis, and mission planning. The astronomical growth in size and performance of data storage systems leads to problems in processing the amount of data returned on any given query. Typical relational database systems return a set of unordered records. This approach is acceptable in small information systems, but in large systems, such as military image retrieval systems with more than 1 million records, it requires considerable time (often hours to days) to sort through …

Netwars Based Study Of A Joint Stars Link-16 Network, Charlie I. Cruz

Theses and Dissertations

Both secure and anti-jam resistant, the Link-16 is the primary communications channel used by the Joint Surveillance Target Attack Radar System (Joint STARS) for the exchange of real-time tactical data among various ground, air, and sea platforms of the United States of America and North Atlantic Treaty Organization forces. This research explored the effect of increasing network traffic for imagery transfer to the mean delay when operating under different network topologies. Using Network Warfare Simulation (NETWARS), three different missions were simulated to run on five network topologies having a different number of participants, different assigned time slots, and stacked nets. …

Visual Debugging Of Object-Oriented Systems With The Unified Modeling Language, Wendell E. Fox

Theses and Dissertations

The Department of Defense (DoD) is developing a Joint Battlespace Infosphere, linking a large number of data sources and user applications. Debugging and analysis tools are required to aid in this process. Debugging of large object-oriented systems is a difficult cognitive process that requires understanding of both the overall and detailed behavior of the application. In addition, many such applications linked through a distributed system add to this complexity. Standard debuggers do not utilize visualization techniques, focusing mainly on information extracted directly from the source code. To overcome this deficiency, this research designs and implements a methodology that enables developers …

Machine Learning Techniques For Characterizing Ieee 802.11b Encrypted Data Streams, Michael J. Henson

Theses and Dissertations

As wireless networks become an increasingly common part of the infrastructure in industrialized nations, the vulnerabilities of this technology need to be evaluated. Even though there have been major advancements in encryption technology, security protocols and packet header obfuscation techniques, other distinguishing characteristics do exist in wireless network traffic. These characteristics include packet size, signal strength, channel utilization and others. Using these characteristics, windows of size 11, 31, and 51 packets are collected and machine learning (ML) techniques are trained to classify applications accessing the 802.11b wireless channel. The four applications used for this study included E-Mail, FTP, HTTP, and …

Comparative Analysis Of Active And Passive Mapping Techniques In An Internet-Based Local Area Network, James B. Kuntzelman

Theses and Dissertations

Network mapping technologies allow quick and easy discovery of computer systems throughout a network. Active mapping methods, such as using nmap, capitalize on the standard stimulus-response of network systems to probe target systems. In doing so, they create extra traffic on the network, both for the initial probe and for the target system's response. Passive mapping methods work opportunistically, listening for network traffic as it transits the system. As such, passive methods generate minimal network traffic overhead. Active methods are still standard methods for network information gathering; passive techniques are not normally used due to the possibility of missing important …

Concurrent Cognitive Mapping And Localization Using Expectation Maximization, Kennard R. Laviers

Theses and Dissertations

Robot mapping remains one of the most challenging problems in robot programming. Most successful methods use some form of occupancy grid for representing a mapped region. An occupancy grid is a two dimensional array in which the array cells represents (x,y) coordinates of a cartesian map. This approach becomes problematic in mapping large environments as the map quickly becomes too large for processing and storage. Rather than storing the map as an occupancy grid, our robot (equipped with ultrasonic sonars) views the world as a series of connected spaces. These spaces are initially mapped as an occupancy grid in a …

Throughput Performance Evaluation And Analysis Of Unmodified Bluetooth Devices, Steven J. Taylor

Theses and Dissertations

The Air Force relies on the application of new technologies to support and execute its mission. As new technologies develop, the integration of that technology is studied to determine the costs and benefits it may provide to the war fighter. One such emergent technology is the Bluetooth wireless protocol, used to connect a small number of devices over a short distance. The short distance is a feature that makes using the protocol desirable. However short, there is still a vulnerability to interception. This research identifies ranges at which several commercially available Bluetooth devices are usable. Various combinations of both distance …

Software Development Outsourcing Decision Support Tool With Neural Network Learning, James D. Newberry

Theses and Dissertations

The Air Force (AF) needs an evolving software tool for guiding decision makers through the complexities of software outsourcing. Previous research identified specific outsourcing strategies and linked them to goals and consequences through a variety of relationship rules. These strategies and relationship rules were inserted into a decision support tool. Since that time, more historical data and outsourcing literature has been collected thus necessitating an update to such a tool. As the number of software outsourcing projects are completed, the AF must capture the outsourcing decision experiences which guided the projects and their outcomes. In order to efficiently incorporate this …

Packet Analysis Of Unmodified Bluetooth Communication Devices, Neal A. Watts

Theses and Dissertations

Bluetooth technology has potential for widespread use within the Department of Defense and the Air Force. An office environment using Bluetooth technology can wirelessly connect computers, printers, and other office equipment in order to share information over short distances. The clutter and annoyance of cables connecting equipment can be eliminated. Bluetooth provides a standard interface for connection, as opposed to many different proprietary cables. The research is conducted indoors in a climate controlled environment, with minimal obstructions, to closely follow free-space signal propagation. Four different antenna orientations are used. The factors varied are the distance between devices, and the antenna …

Effects Of Query Complexity And Learning On Novice User Query Performance With Conceptual And Logical Database Interfaces, Keng Siau, Hock Chuan Chan, Kwok Kee Wei

Research Collection School Of Computing and Information Systems

Users see the database interface as the database system. A good interface enables them to formulate queries better. The semantics communicated through the interface can be classified according to abstraction levels, such as the conceptual and logical levels. With the conceptual interface, interaction is in terms of real-world concepts such as entities, objects and relationships. Current user-database interaction is mainly based on the logical interface, where interaction is in terms of abstract database concepts such as relations and joins. Many researchers argue that end users will perform better with the conceptual interface. This research tested this claim, as well as …

Clash: A Protocol For Internet-Scale Utility-Oriented Distributed Computing, Archan Misra, Paul Castro, Jinwon Lee

Research Collection School Of Computing and Information Systems

Distributed hash table (DHT) overlay networks offer an efficient and robust technique for wire-area data storage and queries. Workload from real applications that use DHT networks will likely exhibit significant skews that can result in bottlenecks and failures that limit the overall scalability of the DHT approach. We present the content and load-aware scalable hashing (CLASH) protocol that can enhance the load distribution behavior of a DHT. CLASH relies on a variable-length identifier key scheme, where the length of any individual key is a function of load. CLASH uses variable-length keys to cluster content-related objects on single nodes to achieve …

Natural Xml For Data Binding, Processing, And Persistence, George K. Thiruvathukal, Konstantin Läufer

Computer Science: Faculty Publications and Other Works

The article explains what you need to do to incorporate XML directly into your computational science application. The exploration involves the use of a standard parser to automatically build object trees entirely from application-specific classes. This discussion very much focuses on object-oriented programming languages such as Java and Python, but it can work for non-object-oriented languages as well. The ideas in the article provide a glimpse into the Natural XML research project.

Phoneme-Based Transliteration Of Foreign Names For Oov Problem, Wei Gao, Kam-Fai Wong, Wai Lam

Research Collection School Of Computing and Information Systems

A proper noun dictionary is never complete rendering name translation from English to Chinese ineffective. One way to solve this problem is not to rely on a dictionary alone but to adopt automatic translation according to pronunciation similarities, i.e. to map phonemes comprising an English name to the phonetic representations of the corresponding Chinese name. This process is called transliteration. We present a statistical transliteration method. An efficient algorithm for aligning phoneme chunks is described. Unlike rule-based approaches, our method is data-driven. Compared to source-channel based statistical approaches, we adopt a direct transliteration model, i.e. the direction of probabilistic estimation …

A Modeling Framework For Computing Lifetime And Information Capacity In Wireless Sensor Networks, Enrique Duarte-Melo, Mingyan Liu, Archan Misra

Research Collection School Of Computing and Information Systems

In this paper we investigate the expected lifetime and information capacity, defined as the maximum amount of data (bits) transferred before the first sensor node death due to energy depletion, of a data-gathering wireless sensor network. We develop a fluidflow based computational framework that extends the existing approach, which requires precise knowledge of the layout/deployment of the network, i.e., exact sensor positions. Our method, on the other hand, views a specific network deployment as a particular instance (sample path) from an underlying distribution of sensor node layouts and sensor data rates.

An Information-Theoretic Framework For Optimal Location Tracking In Multi-System 4g Wireless Networks, Archan Misra, Abhishek Roy, Sajal K. Das

Research Collection School Of Computing and Information Systems

An information-theoretic framework is developed for optimal location management in multisystem, fourth generation (4G) wireless networks. The framework envisions that each individual subsystem operates fairly independently, and does not require public knowledge of individual subnetwork topologies. To capture the variation in paging and location update costs in this heterogeneous environment, the location management problem is formulated in terms of a new concept of weighted entropy. The update process is based on the Lempel-Ziv compression algorithms, which are applied to a vector-valued sequence consisting of both the mobile's movement pattern and its session activity state. Three different tracking strategies which differ …

Group Nearest Neighbor Queries, Dimitris Papadias, Qiongmao Shen, Yufei Tao, Kyriakos Mouratidis

Research Collection School Of Computing and Information Systems

Given two sets of points P and Q, a group nearest neighbor (GNN) query retrieves the point(s) of P with the smallest sum of distances to all points in Q. Consider, for instance, three users at locations q1 , q2 and q3 that want to find a meeting point (e.g., a restaurant); the corresponding query returns the data point p that minimizes the sum of Euclidean distances |pqi| for 1 ≤i ≤3. Assuming that Q fits in memory and P is indexed by an R-tree, we propose several algorithms for finding the group nearest neighbors efficiently. As a second step, …

Efficient Group Pattern Mining Using Data Summarization, Yida Wang, Ee Peng Lim, San-Yih Hwang

Research Collection School Of Computing and Information Systems

In group pattern mining, we discover group patterns from a given user movement database based on their spatio-temporal distances. When both the number of users and the logging duration are large, group pattern mining algorithms become very inefficient. In this paper, we therefore propose a spherical location summarization method to reduce the overhead of mining valid 2-groups. In our experiments, we show that our group mining algorithm using summarized data may require much less execution time than that using non-summarized data.

An Automated Algorithm For Extracting Website Skeleton, Zehua Liu, Wee-Keong Ng, Ee Peng Lim

Research Collection School Of Computing and Information Systems

The huge amount of information available on the Web has attracted many research efforts into developing wrappers that extract data from webpages. However, as most of the systems for generating wrappers focus on extracting data at page-level, data extraction at site-level remains a manual or semi-automatic process. In this paper, we study the problem of extracting website skeleton, i.e. extracting the underlying hyperlink structure that is used to organize the content pages in a given website. We propose an automated algorithm, called the Sew algorithm, to discover the skeleton of a website. Given a page, the algorithm examines hyperlinks in …

Security Analysis Of Some Proxy Signature, Guilin Wang, Feng Bao, Jianying Zhou, Robert H. Deng

Research Collection School Of Computing and Information Systems

A proxy signature scheme allows an entity to delegate his/her signing capability to another entity in such a way that the latter can sign messages on behalf of the former. Such schemes have been suggested for use in a number of applications, particularly in distributed computing where delegation of rights is quite common. Followed by the first schemes introduced by Mambo, Usuda and Okamoto in 1996, a number of new schemes and improvements have been proposed. In this paper, we present a security analysis of four such schemes newly proposed. By successfully identifying several interesting forgery attacks, we show that …

Authenticating Query Results In Edge Computing, Hwee Hwa Pang, Kian-Lee Tan

Research Collection School Of Computing and Information Systems

Edge computing pushes application logic and the underlying data to the edge of the network, with the aim of improving availability and scalability. As the edge servers are not necessarily secure, there must be provisions for validating their outputs. This paper proposes a mechanism that creates a verification object (VO) for checking the integrity of each query result produced by an edge server - that values in the result tuples are not tampered with, and that no spurious tuples are introduced. The primary advantages of our proposed mechanism are that the VO is independent of the database size, and that …

Hiding Data Accesses In Steganographic File System, Xuan Zhou, Hwee Hwa Pang, Kian-Lee Tan

Research Collection School Of Computing and Information Systems

To support ubiquitous computing, the underlying data have to be persistent and available anywhere-anytime. The data thus have to migrate from devices local to individual computers, to shared storage volumes that are accessible over open network. This potentially exposes the data to heightened security risks. We propose two mechanisms, in the context of a steganographic file system, to mitigate the risk of attacks initiated through analyzing data accesses from user applications. The first mechanism is intended to counter attempts to locate data through updates in between snapshots - in short, update analysis. The second mechanism prevents traffic analysis - identifying …

Keyjacking: The Surprising Insecurity Of Client-Side Ssl, John Marchesini, S W. Smith, Meiyuan Zhao

Computer Science Technical Reports

In theory, PKI can provide a flexible and strong way to authenticate users in distributed information systems. In practice, much is being invested in realizing this vision via client-side SSL and various client keystores. However, whether this works depends on whether what the machines do with the private keys matches what the humans think they do: whether a server operator can conclude from an SSL request authenticated with a user's private key that the user was aware of and approved that request. Exploring this vision, we demonstrate via a series of experiments that this assumption does not hold with standard …

Reasoning And Learning With Imperfect Casebases: An Agent Perspective With An Expert Model, Leen-Kiat Soh

School of Computing: Technical Reports

Traditionally, case-based reasoning (CBR) (e.g., Watson and Marir 1994) assumes that the cases in the casebase are correct, useful in both time and space. Otherwise, the cases would not have been stored in the casebase in the first place. Cases are supposed to be useful in guiding us to a successful solution, or in preventing us from repeating the same failure.

Change Tolerant Indexing For Constantly Evolving Data, Reynold Cheng, Yuni Xia, Sunil Prabhakar, Rahul Shah

Department of Computer Science Technical Reports

No abstract provided.

Application-Controlled Loss-Tolerant Data Dissemination, Guanling Chen, David Kotz

Computer Science Technical Reports

Reactive or proactive mobile applications require continuous monitoring of their physical and computational environment to make appropriate decisions in time. These applications need to monitor data streams produced by sensors and react to changes. When mobile sensors and applications are connected by low-bandwidth wireless networks, sensor data rates may overwhelm the capacity of network links or of the applications. In traditional networks and distributed systems, flow-control and congestion-control policies either drop data or force the sender to pause. When the data sender is sensing the physical environment, however, a pause is equivalent to dropping data. Arbitrary data drops are not …

Virtual Teams Combining Mobile Devices With Web-Based Communication On Group Decision Making, Hyo-Joo Han

Dissertations

Organizations have moved from a face-to-face team environment to a virtual team environment using communication technology during the last decade. More and more workers use asynchronous tools (including email, discussion groups, information sharing tools, and group calendaring systems), and synchronous tools, such as instant messaging and web-based chatting features, to coordinate and share information with people within and outside of organizations. This empirical study on how virtual teams work, integrating mobile devices with web-based group communication for decision-making tasks, examines which technologies and communication modes are the best for distributed group teamwork, and, mainly, what are the predictive characteristics making …

The Impacts Of Delphi Communication Structure On Small And Medium Sized Asynchronous Virtual Teams, Hee-Kyung Cho

Dissertations

The improvement of Internet technology has motivated distributed work groups to collaborate without meeting face to face. Although asynchronous meetings through Web-based group communications systems enable groups dispersed temporarily and geographically to collaborate more flexibly, parallel and non-linear communication among dispersed members also challenge effective and efficient group coordination. Moreover, the Web-based asynchronous meeting is distinguished not only from the face-to-face meeting but also from the synchronous computer-supported meeting in terms of coordination process. However, previous asynchronous group communications or virtual team research focused more on the comparison of this new type of meeting with the face-to-face meeting. Not many …

An Analysis Of The Periodicity Of The Cell Cycle And Apoptotic Regulatory Proteins In Prostate Xenografts Using Anova And Cosinor Methods, Aleen Hosdaghian

Theses

Circadian rhythms have been found in both plants and animals, in normal tissues as well as in most tumors and human cancers. By following these rhythms in healthy and cancerous tissue, it has been possible to find optimal times to deliver a dose of drug, such that efficacy is maximized and toxicity to normal tissues is minimized. In this study, the periodicity of several cell cycle and apoptotic regulatory proteins were studied in two prostate cancer models against a dietary therapeutic agent, Selenium. The ALVA-3 1 (androgen-independent) and PC-3 (androgen-independent) prostate cancer cell lines were grown in vivo, as a …

Simulation And Mathematical Notation Of Alarms Unit For Computer Assisted Resuscitation Algorithm, Swaroop Malangi

Theses

The Computer Assisted Resuscitation Algorithm [CARA] is a system that is used to drive a high output infusion pump used for infusing saline into patients suffering from conditions that lead to hypotension. The infusion pump infuses saline at a particular rate into the patient depending on the blood pressure of the patient.

The alarms unit of CARA was simulated for the infusion pump in which the occurrence of alarms depends on the various criteria the infusion pump encounters when saline is being infused into patients. Various criteria may vary from an air bubble in the line to varying high and …