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2008

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Articles 781 - 810 of 1335

Full-Text Articles in Computer Sciences

Automatic Drift Compensation Using Phase Correlation Method For Nanomanipulation, Qinmin Yang, Jagannathan Sarangapani, Eric W. Bohannan Mar 2008

Automatic Drift Compensation Using Phase Correlation Method For Nanomanipulation, Qinmin Yang, Jagannathan Sarangapani, Eric W. Bohannan

Electrical and Computer Engineering Faculty Research & Creative Works

Nanomanipulation and nanofabrication with an atomic force microscope (AFM) or other scanning probe microscope (SPM) are a precursor for nanomanufacturing. It is still a challenging task to accomplish nanomanipulation automatically. In ambient conditions without stringent environmental controls, the task of nanomanipulation requires extensive human intervention to compensate for the spatial uncertainties of the SPM. Among these uncertainties, the thermal drift, which affects spatial resolution, is especially hard to solve because it tends to increase with time, and cannot be compensated simultaneously by feedback from the instrument. In this paper, a novel automatic compensation scheme is introduced to measure and estimate …

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On-Line Discovery Of Hot Motion Paths, Dimitris Sacharidis, Kostas Patroumpas, Manolis Terrovitis, Verena Kantere, Michalis Potamias, Kyriakos Mouratidis, Timos Sellis Mar 2008

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

Research Collection School Of Computing and Information Systems

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, …

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Semantic Components: A Model For Enhancing Retrieval Of Domain- Specific Information, Susan Loucette Price Mar 2008

Semantic Components: A Model For Enhancing Retrieval Of Domain- Specific Information, Susan Loucette Price

Dissertations and Theses

Despite the success of general Internet search engines, information retrieval remains an incompletely solved problem. Our research focuses on supporting domain experts when they search domain-specific libraries to satisfy targeted information needs. The semantic components model introduces a schema specific to a particular document collection. A semantic component schema consists of a two-level hierarchy, document classes and semantic components. A document class represents a document grouping, such as topic type or document purpose. A semantic component is a characteristic type of information that occurs in a particular document class and represents an important aspect of the document’s main topic. …

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An Analysis Of Information Asset Valuation (Iav) Quantification Methodology For Application With Cyber Information Mission Impact Assessment (Cimia), Denzil L. Hellesen Mar 2008

An Analysis Of Information Asset Valuation (Iav) Quantification Methodology For Application With Cyber Information Mission Impact Assessment (Cimia), Denzil L. Hellesen

Theses and Dissertations

The purpose of this research is to develop a standardized Information Asset Valuation (IAV) methodology. The IAV methodology proposes that accurate valuation for an Information Asset (InfoA) is the convergence of information tangible, intangible, and flow attributes to form a functional entity that enhances mission capability. The IAV model attempts to quantify an InfoA to a single value through the summation of weighted criteria. Standardizing the InfoA value criteria will enable decision makers to comparatively analyze dissimilar InfoAs across the tactical, operational, and strategic domains. This research develops the IAV methodology through a review of existing military and non-military valuation …

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Dynamic Protocol Reverse Engineering A Grammatical Inference Approach, Mark E. Deyoung Mar 2008

Dynamic Protocol Reverse Engineering A Grammatical Inference Approach, Mark E. Deyoung

Theses and Dissertations

Round trip engineering of software from source code and reverse engineering of software from binary files have both been extensively studied and the state-of-practice have documented tools and techniques. Forward engineering of protocols has also been extensively studied and there are firmly established techniques for generating correct protocols. While observation of protocol behavior for performance testing has been studied and techniques established, reverse engineering of protocol control flow from observations of protocol behavior has not received the same level of attention. State-of-practice in reverse engineering the control flow of computer network protocols is comprised of mostly ad hoc approaches. We …

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A Novel Communications Protocol Using Geographic Routing For Swarming Uavs Performing A Search Mission, Robert L. Lidowski Mar 2008

A Novel Communications Protocol Using Geographic Routing For Swarming Uavs Performing A Search Mission, Robert L. Lidowski

Theses and Dissertations

This research develops the UAV Search Mission Protocol (USMP) for swarming UAVs and determines the protocol's effect on search mission performance. It is hypothesized that geographically routing USMP messages improves search performance by providing geography-dependent data to locations where it impacts search decisions. It is also proposed that the swarm can use data collected by the geographic routing protocol to accurately determine UAV locations and avoid sending explicit location updates. The hypothesis is tested by developing several USMP designs that are combined with the Greedy Perimeter Stateless Routing (GPSR) protocol and a search mission swarm logic into a single network …

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Software Obfuscation With Symmetric Cryptography, Alan C. Lin Mar 2008

Software Obfuscation With Symmetric Cryptography, Alan C. Lin

Theses and Dissertations

Software protection is of great interest to commercial industry. Millions of dollars and years of research are invested in the development of proprietary algorithms used in software programs. A reverse engineer that successfully reverses another company‘s proprietary algorithms can develop a competing product to market in less time and with less money. The threat is even greater in military applications where adversarial reversers can use reverse engineering on unprotected military software to compromise capabilities on the field or develop their own capabilities with significantly less resources. Thus, it is vital to protect software, especially the software’s sensitive internal algorithms, from …

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Creating An Agent Based Framework To Maximize Information Utility, John M. Pecarina Mar 2008

Creating An Agent Based Framework To Maximize Information Utility, John M. Pecarina

Theses and Dissertations

With increased reliance on communications to conduct military operations, information centric network management becomes vital. A Defense department study of information management for net-centric operations lists the need for tools for information triage (based on relevance, priority, and quality) to counter information overload, semi-automated mechanisms for assessment of quality and relevance of information, and advances to enhance cognition and information understanding in the context of missions [30]. Maximizing information utility to match mission objectives is a complex problem that requires a comprehensive solution in information classification, in scheduling, in resource allocation, and in QoS support. Of these research areas, the …

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Algorithms For White-Box Obfuscation Using Randomized Subcircuit Selection And Replacement, Kenneth E. Norman Mar 2008

Algorithms For White-Box Obfuscation Using Randomized Subcircuit Selection And Replacement, Kenneth E. Norman

Theses and Dissertations

Software protection remains an active research area with the goal of preventing adversarial software exploitation such as reverse engineering, tampering, and piracy. Heuristic obfuscation techniques lack strong theoretical underpinnings while current theoretical research highlights the impossibility of creating general, efficient, and information theoretically secure obfuscators. In this research, we consider a bridge between these two worlds by examining obfuscators based on the Random Program Model (RPM). Such a model envisions the use of program encryption techniques which change the black-box (semantic) and white-box (structural) representations of underlying programs. In this thesis we explore the possibilities for white-box transformation. Under an …

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Signal Processing Design Of Low Probability Of Intercept Waveforms, Nathaniel C. Liefer Mar 2008

Signal Processing Design Of Low Probability Of Intercept Waveforms, Nathaniel C. Liefer

Theses and Dissertations

This thesis investigates a modification to Differential Phase Shift Keyed (DPSK) modulation to create a Low Probability of Interception/Exploitation (LPI/LPE) communications signal. A pseudorandom timing offset is applied to each symbol in the communications stream to intentionally create intersymbol interference (ISI) that hinders accurate symbol estimation and bit sequence recovery by a non-cooperative receiver. Two cooperative receiver strategies are proposed to mitigate the ISI due to symbol timing offset: a modified minimum Mean Square Error (MMSE) equalization algorithm and a multiplexed bank of equalizer filters determined by an adaptive Least Mean Square (LMS) algorithm. Both cooperative receivers require some knowledge …

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Identification Of Command And Control Information Requirements For The Cyberspace Domain, Brian D. Aschenbrenner Mar 2008

Identification Of Command And Control Information Requirements For The Cyberspace Domain, Brian D. Aschenbrenner

Theses and Dissertations

The purpose of this research was to develop an information requirements analysis method that would provide the Director of Cyberspace Forces with the information required to support effective command and control of cyberspace. This research investigates the role of information in command and control, information in the traditional war fighting domains, cyberspace as a war fighting domain, and various methods of determining information requirements of organizations. This research produced an information requirements analysis method that is suitable for identifying the command and control information requirements of the Director of Cyberspace Forces.

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Cyber Flag: A Realistic Cyberspace Training Construct, Andrew P. Hansen Mar 2008

Cyber Flag: A Realistic Cyberspace Training Construct, Andrew P. Hansen

Theses and Dissertations

As is well understood, the rapidly unfolding challenges of cyberspace is a fundamental warfare paradigm shift revolutionizing the way future wars will be fought and won. A significant test for the Air Force (indeed any organization with a credible presence in cyberspace) will be providing a realistic training environment that fully meets this challenge. Why create another Flag level exercise? Realistic training (that which is effective, comprehensive and coordinated) is crucial to success in time of war. Red Flag provides dominant training within the air domain and now with the evolution of cyberspace, a comprehensive training environment is necessary to …

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Multi-Class Classification Fusion Using Boosting For Identifying Steganography Methods, Benjamin M. Rodriguez, Gilbert L. Peterson Mar 2008

Multi-Class Classification Fusion Using Boosting For Identifying Steganography Methods, Benjamin M. Rodriguez, Gilbert L. Peterson

Faculty Publications

No abstract provided.

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Active Behavioral Fingerprinting Of Wireless Devices, Sergey Bratus, Cory Cornelius, David Kotz, Dan Peebles Mar 2008

Active Behavioral Fingerprinting Of Wireless Devices, Sergey Bratus, Cory Cornelius, David Kotz, Dan Peebles

Dartmouth Scholarship

We propose a simple active method for discovering facts about the chipset, the firmware or the driver of an 802.11 wireless device by observing its responses (or lack thereof) to a series of crafted non-standard or malformed 802.11 frames. We demonstrate that such responses can differ significantly enough to distinguish between a number of popular chipsets and drivers. We expect to significantly expand the number of recognized device types through community contributions of signature data for the proposed open fingerprinting framework. Our method complements known fingerprinting approaches, and can be used to interrogate and spot devices that may be spoofing …

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Harmoni: Context-Aware Filtering Of Sensor Data For Continuous Remote Health Monitoring, Iqbal Mohomed, Archan Misra, Maria Ebling, William Jerome Mar 2008

Harmoni: Context-Aware Filtering Of Sensor Data For Continuous Remote Health Monitoring, Iqbal Mohomed, Archan Misra, Maria Ebling, William Jerome

Research Collection School Of Computing and Information Systems

A promising architecture for remote healthcare monitoring involves the use of a pervasive device (such as a cellular phone), which aggregates data from multiple body-worn medical sensors and transmits the data to the backend. Unfortunately, the volume of data generated by increasingly sophisticated continuouslyactive sensors can overwhelm the resources on the mobile device. We propose imbuing the mobile device with the intelligence to perform context-aware filtering of sensor data streams in order to reduce transmissions in cases where the observed data corresponds to the norm expected by the system in a given context. To investigate the efficacy of this technique, …

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Sub-Symbolic Re-Representation To Facilitate Learning Transfer, Dan A. Ventura Mar 2008

Sub-Symbolic Re-Representation To Facilitate Learning Transfer, Dan A. Ventura

Faculty Publications

We consider the issue of knowledge (re-)representation in the context of learning transfer and present a subsymbolic approach for effecting such transfer. Given a set of data, manifold learning is used to automatically organize the data into one or more representational transformations, which are then learned with a set of neural networks. The result is a set of neural filters that can be applied to new data as re-representation operators. Encouraging preliminary empirical results elucidate the approach and demonstrate its feasibility, suggesting possible implications for the broader field of creativity.

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Processing Transitive Nearest-Neighbor Queries In Multi-Channel Access Environments, Xiao Zhang, Wang-Chien Lee, Prasnjit Mitra, Baihua Zheng Mar 2008

Processing Transitive Nearest-Neighbor Queries In Multi-Channel Access Environments, Xiao Zhang, Wang-Chien Lee, Prasnjit Mitra, Baihua Zheng

Research Collection School Of Computing and Information Systems

Wireless broadcast is an efficient way for information dissemination due to its good scalability [10]. Existing works typically assume mobile devices, such as cell phones and PDAs, can access only one channel at a time. In this paper, we consider a scenario of near future where a mobile device has the ability to process queries using information simultaneously received from multiple channels. We focus on the query processing of the transitive nearest neighbor (TNN) search [19]. Two TNN algorithms developed for a single broadcast channel environment are adapted to our new broadcast enviroment. Based on the obtained insights, we propose …

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Ant Clustering With Locally Weighting Ant Perception And Diversified Memory, Gilbert L. Peterson, Christopher B. Mayer, Thomas L. Kubler Mar 2008

Ant Clustering With Locally Weighting Ant Perception And Diversified Memory, Gilbert L. Peterson, Christopher B. Mayer, Thomas L. Kubler

Faculty Publications

Ant clustering algorithms are a robust and flexible tool for clustering data that have produced some promising results. This paper introduces two improvements that can be incorporated into any ant clustering algorithm: kernel function similarity weights and a similarity memory model replacement scheme. A kernel function weights objects within an ant’s neighborhood according to the object distance and provides an alternate interpretation of the similarity of objects in an ant’s neighborhood. Ants can hill-climb the kernel gradients as they look for a suitable place to drop a carried object. The similarity memory model equips ants with a small memory consisting …

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The Importance Of Generalizability To Anomaly Detection, Gilbert L. Peterson, Brent T. Mcbride Mar 2008

The Importance Of Generalizability To Anomaly Detection, Gilbert L. Peterson, Brent T. Mcbride

Faculty Publications

In security-related areas there is concern over novel “zero-day” attacks that penetrate system defenses and wreak havoc. The best methods for countering these threats are recognizing “nonself” as in an Artificial Immune System or recognizing “self” through clustering. For either case, the concern remains that something that appears similar to self could be missed. Given this situation, one could incorrectly assume that a preference for a tighter fit to self over generalizability is important for false positive reduction in this type of learning problem. This article confirms that in anomaly detection as in other forms of classification a tight fit, …

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4-(4-Chlorophenyl)-5-[1-(4-Chlorophenyl)-2-Methyl-2-Nitropropyl]-1,2,3-Selenadiazole, A. Marx, S. Saravanan, S. Muthusubramanian, V. Manivannan, Nigam Rath Feb 2008

4-(4-Chlorophenyl)-5-[1-(4-Chlorophenyl)-2-Methyl-2-Nitropropyl]-1,2,3-Selenadiazole, A. Marx, S. Saravanan, S. Muthusubramanian, V. Manivannan, Nigam Rath

Chemistry & Biochemistry Faculty Works

In the title compound, C18H15Cl2N3O2Se, the selenadiazole ring makes dihedral angles of 49.87 (3) and 55.70 (3)° with the two benzene rings. The dihedral angle between the two benzene rings is 11.90 (5)°. In the crystal structure, intra­molecular C-H...O and C-H...Se inter­actions and inter­molecular C-H...O, C-H...Cl and C-H...N inter­actions are observed.

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Controlling Information Technology Costs And Reporting Roi In Large Organizations, Darrell Jones Feb 2008

Controlling Information Technology Costs And Reporting Roi In Large Organizations, Darrell Jones

Regis University Student Publications (comprehensive collection)

Controlling the cost of information technology (IT) and reporting return on investment in such technologies in large organizations has long been problematic because IT is a significant cost center that in most companies does not contribute directly to the generation of revenue. At the same time, the services provided by IT departments directly affect the bottom lines of modern companies and provide valuable efficiencies. Measuring and reporting the effects of those efficiencies has been hampered by two fairly typical shortcomings of IT managers. IT managers whose primary training is in their own discipline tend to view technology issues in terms …

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Semantic Sensor Web, Amit P. Sheth, Cory Andrew Henson Feb 2008

Semantic Sensor Web, Amit P. Sheth, Cory Andrew Henson

Kno.e.sis Publications

No abstract provided.

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Approximate Owl Instance Retrieval With Screech, Pascal Hitzler, Markus Krotzsch, Sebastian Rudolph, Tuvshintur Tserendorj Feb 2008

Approximate Owl Instance Retrieval With Screech, Pascal Hitzler, Markus Krotzsch, Sebastian Rudolph, Tuvshintur Tserendorj

Computer Science and Engineering Faculty Publications

With the increasing interest in expressive ontologies for the Semantic Web, it is critical to develop scalable and efficient ontology reasoning techniques that can properly cope with very high data volumes. For certain application domains, approximate reasoning solutions, which trade soundness or completeness for increased reasoning speed, will help to deal with the high computational complexities which state of the art ontology reasoning tools have to face. In this paper, we present a comprehensive overview of the SCREECH approach to approximate instance retrieval with OWL ontologies, which is based on the KAON2 algorithms, facilitating a compilation of OWL DL TBoxes …

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Garuda: Achieving Effective Reliability For Downstream Communication In Wireless Sensor Networks, Seung Jong Park, Ramanuja Vedantham, Raghupathy Sivakumar, Ian F. Akyildiz Feb 2008

Garuda: Achieving Effective Reliability For Downstream Communication In Wireless Sensor Networks, Seung Jong Park, Ramanuja Vedantham, Raghupathy Sivakumar, Ian F. Akyildiz

Computer Science Faculty Research & Creative Works

There exist several applications of sensor networks where the reliability of data delivery can be critical. Although the redundancy inherent in a sensor network might increase the degree of reliability, it by no means can provide any guaranteed reliability semantics. In this paper, we consider the problem of reliable sink-to-sensors data delivery. We first identify several fundamental challenges that need to be addressed and are unique to the environment of wireless sensor networks. We then propose a scalable framework for reliable downstream data delivery that is specifically designed to both address and leverage the characteristics of the wireless sensor networks …

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Loss-Rate Based Reliable Data Transport Mechanism For Dynamic Event Sensing In Wireless Sensor Networks, Yuyan Xue, Byrav Ramamurthy, Yong Wang Feb 2008

Loss-Rate Based Reliable Data Transport Mechanism For Dynamic Event Sensing In Wireless Sensor Networks, Yuyan Xue, Byrav Ramamurthy, Yong Wang

School of Computing: Technical Reports

Many wireless sensor network (WSN) transport protocols proposed in recent studies focus on providing end-to- end reliability as in TCP. However, traditional end-to-end reliability is energy and time consuming for common loss tolerant applications in WSNs. In this paper, we propose a Loss Tolerant Reliable (LTR) data transport mechanism for dynamic Event Sensing (LTRES) in WSNs. In LTRES, a reliable event sensing requirement at the transport layer is dynamically determined by the sink. A distributed source rate adaptation mechanism is designed, incorporating a loss rate based lightweight congestion control mechanism, to regulate the data traffic injected into the network so …

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Better Refactoring Tools For A Better Refactoring Strategy, Andrew P. Black Feb 2008

Better Refactoring Tools For A Better Refactoring Strategy, Andrew P. Black

Computer Science Faculty Publications and Presentations

Refactoring tools can improve the speed and accuracy with which we create and maintain software – but only if they are used. In practice, tools are not used as much as they could be; this seems to be because they do not align with the refactoring strategy preferred by the majority of programmers: floss refactoring. We propose five principles that characterize successful floss refactoring tools – principles that can help programmers to choose the most appropriate refactoring tools and also help toolsmiths to design more usable tools.

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The State Of The Art In Flow Visualization: Partition-Based Techniques, Tobias Salzbrunn, Heike Janicke, Thomas Wischgoll, Gerik Scheuermann Feb 2008

The State Of The Art In Flow Visualization: Partition-Based Techniques, Tobias Salzbrunn, Heike Janicke, Thomas Wischgoll, Gerik Scheuermann

Computer Science and Engineering Faculty Publications

Flow visualization has been a very active subfield of scientific visualization in recent years. From the resulting large variety of methods this paper discusses partition-based techniques. The aim of these approaches is to partition the flow in areas of common structure. Based on this partitioning, subsequent visualization techniques can be applied. A classification is suggested and advantages/disadvantages of the different techniques are discussed as well.

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Knowledge Management For Disparate Etruscan Cultural Heritage, John Mcauley, James Carswell Feb 2008

Knowledge Management For Disparate Etruscan Cultural Heritage, John Mcauley, James Carswell

Conference papers

This paper introduces the TARCHNA approach to managing and presenting contextualised heritage content. The system uses the CIDOC CRM ontology to consolidate a virtual repository of geographically disparate heritage databases and present a holistic view of a fragmented heritage. While previous approaches to presenting heritage collections have focused on the browse and search paradigm, the TARCHNA system uses narrative concepts as a means of presenting and re-using contextualised heritage artefacts within a broader cultural setting.

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Botsniffer: Detecting Botnet Command And Control Channels In Network Traffic, Guofei Gu, Junjie Zhang, Wenke Lee Feb 2008

Botsniffer: Detecting Botnet Command And Control Channels In Network Traffic, Guofei Gu, Junjie Zhang, Wenke Lee

Computer Science and Engineering Faculty Publications

Botnets are now recognized as one of the most serious security threats. In contrast to previous malware, botnets have the characteristic of a command and control (C&C) channel. Botnets also often use existing common protocols, e.g., IRC, HTTP, and in protocol-conforming manners. This makes the detection of botnet C&C a challenging problem. In this paper, we propose an approach that uses network-based anomaly detection to identify botnet C&C channels in a local area network without any prior knowledge of signatures or C&C server addresses. This detection approach can identify both the C&C servers and infected hosts in the network. Our …

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A Suite Of Robust Controllers For The Manipulation Of Microscale Objects, Qinmin Yang, Jagannathan Sarangapani Feb 2008

A Suite Of Robust Controllers For The Manipulation Of Microscale Objects, Qinmin Yang, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

A suite of novel robust controllers is introduced for the pickup operation of microscale objects in a microelectromechanical system (MEMS). In MEMS, adhesive, surface tension, friction, and van der Waals forces are dominant. Moreover, these forces are typically unknown. The proposed robust controller overcomes the unknown contact dynamics and ensures its performance in the presence of actuator constraints by assuming that the upper bounds on these forces are known. On the other hand, for the robust adaptive critic-based neural network (NN) controller, the unknown dynamic forces are estimated online. It consists of an action NN for compensating the unknown system …

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