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2006

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Articles 2791 - 2820 of 5872

Full-Text Articles in Physical Sciences and Mathematics

A Practical Password-Based Two-Server Authentication And Key Exchange System, Yanjiang Yang, Robert H. Deng, Feng Bao Apr 2006

A Practical Password-Based Two-Server Authentication And Key Exchange System, Yanjiang Yang, Robert H. Deng, Feng Bao

Research Collection School Of Computing and Information Systems

Most password-based user authentication systems place total trust on the authentication server where cleartext passwords or easily derived password verification data are stored in a central database. Such systems are, thus, by no means resilient against offline dictionary attacks initiated at the server side. Compromise of the authentication server by either outsiders or insiders subjects all user passwords to exposure and may have serious legal and financial repercussions to an organization. Recently, several multiserver password systems were proposed to circumvent the single point of vulnerability inherent in the single-server architecture. However, these multiserver systems are difficult to deploy and operate …

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Enterprise Agility And The Enabling Role Of Information Technology, Eric Overby, Anandhi S. Bharadwaj, V. Sambamurthy Apr 2006

Enterprise Agility And The Enabling Role Of Information Technology, Eric Overby, Anandhi S. Bharadwaj, V. Sambamurthy

Research Collection School Of Computing and Information Systems

In turbulent environments, enterprise agility, that is, the ability of firms to sense environmental change and respond readily, is an important determinant of firm success. We define and deconstruct enterprise agility, delineate enterprise agility from similar concepts in the business research literature, explore the underlying capabilities that support enterprise agility, explicate the enabling role of information technology (IT) and digital options, and propose a method for measuring enterprise agility. The concepts in this paper are offered as foundational building blocks for the overall research program on enterprise agility and the enabling role of IT.

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Performance-Metric Driven Atmospheric Compensation For Robust Free-Space Laser Communication, Peter N. Crabtree Apr 2006

Performance-Metric Driven Atmospheric Compensation For Robust Free-Space Laser Communication, Peter N. Crabtree

Theses and Dissertations

The effect of turbulence on laser propagation is a significant challenge to current electro-optical systems. While atmospheric compensation techniques in space object imaging and high-energy laser weapons have been thoroughly investigated, optimizing these techniques for Laser Communication (LaserCom) has not been examined to the same degree. Average Strehl ratio is the typical design metric for current atmospheric compensation systems. However, fade probability is the relevant metric for LaserCom. This difference motivated the investigation into metric-driven atmospheric compensation. Metric-based tracking techniques for fade mitigation is the first major focus of this research. In a moderate range air-to-air scenario, focal plane spot …

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Dynamics Of Nonlinear Diffusion Processes, Dustin A. Sipka Apr 2006

Dynamics Of Nonlinear Diffusion Processes, Dustin A. Sipka

Master's Theses - Daytona Beach

The purpose of this thesis is to analyze nonlinear diffusion processes. In particular, some of the results arrived at by Newman and Sagan in their 1981 paper "Galactic Civilizations: Population Dynamics and Interstellar Diffusion," will be reproduced by different means. First, a thorough analysis of the linear diffusion equation will be performed in order to test a numerical algorithm that can solve the nonlinear diffusion equation and look at the processes of interest with sufficient accuracy. Once the algorithm is tested and shows good resolution it is used to solve the nonlinear equation. The post processing is then done to …

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Traffic Grooming, Routing, And Wavelength Assignment In Wdm Transport Networks With Sparse Grooming Resources, Osama Awwad Apr 2006

Traffic Grooming, Routing, And Wavelength Assignment In Wdm Transport Networks With Sparse Grooming Resources, Osama Awwad

Masters Theses

While a single fiber strand in wavelength division multiplexing (WDM) has over a terabit-per-second bandwidth and a wavelength channel has over a gigabit-persecond transmission speed, the network may still be required to support traffic requests at rates that are lower than the full wavelength capacity. To avoid assigning an entire lightpath to a small request, many researchers have looked at adding traffic grooming to the routing and wavelength assignment (RWA) problem. In this work, we consider the RWA problem with traffic grooming (GRWA) for mesh networks under static and dynamic lightpath connection requests. The GRWA problem is NPComplete since it …

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Structural And Magnetic Properties Of La Mn₁₋ₓfeₓo₃ (0 < X < 1.0), X.-D. Zhou, L. R. Pederson, Qingsheng Cai, Jinbo Yang, B. J. Scarfino, M. Kim, William B. Yelon, William Joseph James, Harlan U. Anderson, C. Wang Apr 2006

Structural And Magnetic Properties Of La Mn₁₋ₓfeₓo₃ (0 < X < 1.0), X.-D. Zhou, L. R. Pederson, Qingsheng Cai, Jinbo Yang, B. J. Scarfino, M. Kim, William B. Yelon, William Joseph James, Harlan U. Anderson, C. Wang

Materials Science and Engineering Faculty Research & Creative Works

Electronic, structural, and magnetic properties of Mn-doped lanthanum ferrites were studied by neutron diffraction, superconducting quantum interference device, and impedance spectroscopy. Neutron diffraction refinements were performed with the constraint of full La occupancy, which showed the presence of excess oxygen when x < 0.4. Mixed valent Mn cations and cation vacancies, therefore, exist in all the samples. The samples with x > 0.7 are magnetically ordered at room temperature with orthorhombic symmetry (Pbnm). When x < 0.3 the structure is rhombohedral and magnetically disordered above 16 K. The majority carriers, electron holes, correspond to high oxidation states of Mn. The carrier concentration is determined from the Seebeck coefficients, and is a function of temperature and Fe concentration. The measurements of conductivity and Seebeck coefficients show polaron hopping at elevated temperatures.

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Volunteer System Project: Regis University Networking Lab Practicum, Desirea Duarte Ulibarri Apr 2006

Volunteer System Project: Regis University Networking Lab Practicum, Desirea Duarte Ulibarri

Regis University Student Publications (comprehensive collection)

The Regis University Networking Lab Practicum (NLP) allows MSCIT graduate students the opportunity to gain hands-on experience in IT topics in a controlled computer network environment. The NLP also introduces students to a wide range of external IT projects such as the Volunteer System Project. The Volunteer System Project was the construction of a database system for a non-profit organization. The Volunteer System captures all of the personnel data, work time and project affiliation information and is a critical tool in managing and maintaining a successful volunteer workforce. The performance of the original spreadsheet-based Volunteer System was declining and could …

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Correction To "Dependence, Dispersiveness, And Multivariate Hazard Rate Ordering", Baha-Eldin Khaledi, Subhash C. Kochar Apr 2006

Correction To "Dependence, Dispersiveness, And Multivariate Hazard Rate Ordering", Baha-Eldin Khaledi, Subhash C. Kochar

Mathematics and Statistics Faculty Publications and Presentations

In the article published last year, three inequalities should be in the opposite direction.

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Homogeneous Products Of Conjugacy Classes, Edith Adan-Bante Apr 2006

Homogeneous Products Of Conjugacy Classes, Edith Adan-Bante

Faculty Publications

Let G be a finite group and a ∈G. Let a G ={g −1 a g | g ∈ G} be the conjugacy class of a in G. Assume that a G and b G are conjugacy classes of G with the property that C G (a)=C G (b). Then a G b G is a conjugacy class if and only if [a,G]=[b,G]=[ab,G] and [ab,G] is a normal subgroup of G.

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Application Of Software Engineering Best Practices And Principles To Small Development Teams, Miles Phillips Apr 2006

Application Of Software Engineering Best Practices And Principles To Small Development Teams, Miles Phillips

Computer Science and Engineering Theses

The motivation of this thesis comes from the professional experience of the author. Having worked with very small software development teams in various capacities, he realized that significant improvements could be achieved by the application of modern software engineering practices and principles. This paper is the result of researching how the principles and practices promoted by the leading software development authors can be applied to the small development team as they transition from "programming in the small" to "programming in the medium." This paper investigates the best practices and principles in various case studies with the objective to clearly define …

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The Advantages Of Implementing Software Engineering Process Models, Ricky Don Preuninger Apr 2006

The Advantages Of Implementing Software Engineering Process Models, Ricky Don Preuninger

Computer Science and Engineering Theses

The North Atlantic Treaty Organization Science Committee had discussions on the topic concerned the state of Computer Science. There were worldwide issues with the development of software, the crisis being that software projects did not seem ever to complete. The study group coined the term "software engineering" to be provocative and implying need for software manufacturing to be similar to traditional branches of engineering. In the beginning, individual programmers used whatever means worked to build software. Formal methods of design or programming did not exist. Programmers were never able to give a definitive estimate as to how long a project …

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A Performance Evaluation Of Alternate Numbering Based Xml Indexing Techniques, Chul Ho Ahn Apr 2006

A Performance Evaluation Of Alternate Numbering Based Xml Indexing Techniques, Chul Ho Ahn

Computer Science and Engineering Theses

Since XML became a standard of representing semi-structured data and exchanging format over the web, the sheer volume of XML data has become larger. While relational database represents data as a structured format, XML represents data in a self-describing way as a hierarchical tree structure. For expediting query processing over XML, many different types of indexing techniques have emerged. We will focus on numbering-based indexing techniques in this thesis. We will present performance comparison according to different XPath queries among three distinct numbering based XML indexing named GENE (Generic numbering based), XISS (Range based numbering), and XACC (Dimension based numbering) …

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Monitorexplorer: A State-Space Exploration Based Tool To Test Java Monitors Implementations, Vidur Gupta Apr 2006

Monitorexplorer: A State-Space Exploration Based Tool To Test Java Monitors Implementations, Vidur Gupta

Computer Science and Engineering Theses

A monitor is a concurrency construct that encapsulates data. There are many application classes which are written using the Java Monitors and these are difficult to test due to the inherent complexities of the concurrent programs. The key challenge is to be able to trace all possible execution paths and then able to reproduce them for regression testing. Our work explores the state-space of the monitor application. The state space is explored in the depth first fashion. At each state the next possible transition is executed. This process is repeated till a duplicate or invalid state is detected. The key …

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Bridging Two Grids: The Sam-Grid/Lcg Integration Project, Tummalapalli Sudhamsh Reddy Apr 2006

Bridging Two Grids: The Sam-Grid/Lcg Integration Project, Tummalapalli Sudhamsh Reddy

Computer Science and Engineering Theses

SAM-Grid is an integrated data, job, and information management system. SAM-Grid addresses the distributed computing needs of the Dzero experiment at Fermi National Accelerator Laboratory, Batavia, IL. The system typically relies on SAM-Grid specific services deployed at the remote sites in order to manage the computing and storage resources. Such deployment requires special agreements with each resource provider, and it is a labor intensive process. Some members of the Dzero VO also have access to computing resources through the Large Hydron Collider Computing Grid (LCG) infrastructure. Therefore, Dzero users can enter into resource sharing agreements and deployment of standard middleware …

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The High-Resolution Structures Of The Neutral And The Low Ph Crystals Of Aminopeptidase From Aeromonas Proteolytica, William Desmarais, David L. Bienvenue, Krzysztof P. Bzymek, Gregory A. Petsko, Dagmar Ringe, Richard C. Holz Apr 2006

The High-Resolution Structures Of The Neutral And The Low Ph Crystals Of Aminopeptidase From Aeromonas Proteolytica, William Desmarais, David L. Bienvenue, Krzysztof P. Bzymek, Gregory A. Petsko, Dagmar Ringe, Richard C. Holz

Chemistry Faculty Research and Publications

The aminopeptidase from Aeromonas proteolytica (AAP) contains two zinc ions in the active site and catalyzes the degradation of peptides. Herein we report the crystal structures of AAP at 0.95-Å resolution at neutral pH and at 1.24-Å resolution at low pH. The combination of these structures allowed the precise modeling of atomic positions, the identification of the metal bridging oxygen species, and insight into the physical properties of the metal ions. On the basis of these structures, a new putative catalytic mechanism is proposed for AAP that is likely relevant to all binuclear metalloproteases.

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In-Network Processing Of Nearest Neigbor Queries For Wireless Sensor Networks, Yuxia Yao, Xueyan Tang, Ee Peng Lim Apr 2006

In-Network Processing Of Nearest Neigbor Queries For Wireless Sensor Networks, Yuxia Yao, Xueyan Tang, Ee Peng Lim

Research Collection School Of Computing and Information Systems

Wireless sensor networks have been widely used for civilian and military applications, such as environmental monitoring and vehicle tracking. The sensor nodes in the network have the abilities to sense, store, compute and communicate. To enable object tracking applications, spatial queries such as nearest neighbor queries are to be supported in these networks. The queries can be injected by the user at any sensor node. Due to the limited power supply for sensor nodes, energy efficiency is the major concern in query processing. Centralized data storage and query processing schemes do not favor energy efficiency. In this paper, we propose …

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Experimental And Empirical Perspectives On Grid Resource Allocation For The Singapore Market, Danny Oh, Steven Miller, Nan Hu Apr 2006

Experimental And Empirical Perspectives On Grid Resource Allocation For The Singapore Market, Danny Oh, Steven Miller, Nan Hu

Research Collection School Of Computing and Information Systems

In this paper, we describe our work on using the Tycoon system developed by HP Labs to provide a market-based resource allocation and bidding framework for a grid. We discuss how we intend to evaluate the feasibility of the Tycoon system by measuring its economic performance using agent-based simulation experiments for a particular type of grid usage scenario, namely, the digital media market scenario. We will also discuss a related effort in collecting and using real grid data from the National Grid Pilot Platform in Singapore and how we will be using real data collected to derive actual usage patterns …

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Factors Affecting The Distribution And Health Of The Intertidal Coral Goniastrea Aspera On The Reef Flat In Geoffrey Bay, Magnetic Island, Julia Smith Apr 2006

Factors Affecting The Distribution And Health Of The Intertidal Coral Goniastrea Aspera On The Reef Flat In Geoffrey Bay, Magnetic Island, Julia Smith

Independent Study Project (ISP) Collection

The intertidal zone can be a harsh environment, presenting many challenges to the organisms inhabiting it. Given its dynamic nature, it is surprising that it is sometimes able to sustain systems as delicate and sensitive as coral reefs. Many organisms have adapted to life on the intertidal reef flat, and one of the most prominent on the northeastern coast of Australia is the massive coral Goniastrea aspera. The mechanisms driving the distribution of this species are not entirely understood; this study investigated the potential role of microhabitat, as well as that of actual physical characteristics of the colonies, in the …

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The Development Of Environmental Consciousness And Identity In Surfing Subculture, Alex Mass Apr 2006

The Development Of Environmental Consciousness And Identity In Surfing Subculture, Alex Mass

Independent Study Project (ISP) Collection

Since the 1960’s and 1970’s, surfing has exuded the stereotype of a laid-back, environmentally conscious and left-wing culture, a connotation often spread through media outlets such as movies, television, and music that encourage the idea. While the stereotype is often known and widely accepted, no studies could be found that actually tested this view. Using a series of interviews and surveys of the New Ecological Paradigm, this study investigated the formation of environmental consciousness and identity in surfing subculture in order to examine the accuracy of such stereotypes, and analyse the effect that such generalized views have on the formation …

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New Developments Of The Deformation Method, Jie Liu Apr 2006

New Developments Of The Deformation Method, Jie Liu

Mathematics Dissertations

New developments of deformation method for grid generation are presented in this work. Theorems for three different cases and different methods for implementing deformation method are presented. One of the new developments is a 3D multi-block moving grid method. In this version, a Poisson equation is solved by finite difference method to get the vector field for moving grid. Special treatment applies to the common boundary of different blocks. Another new development is a numerical method for reconstructing a given differentiable transformations by solving a system of div-curl equation directly formed from each point of the graph. The determinacy and …

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Sgpm: Static Group Pattern Mining Using Apriori-Like Sliding Window, John Goh, David Taniar, Ee Peng Lim Apr 2006

Sgpm: Static Group Pattern Mining Using Apriori-Like Sliding Window, John Goh, David Taniar, Ee Peng Lim

Research Collection School Of Computing and Information Systems

Mobile user data mining is a field that focuses on extracting interesting pattern and knowledge out from data generated by mobile users. Group pattern is a type of mobile user data mining method. In group pattern mining, group patterns from a given user movement database is found based on spatio-temporal distances. In this paper, we propose an improvement of efficiency using area method for locating mobile users and using sliding window for static group pattern mining. This reduces the complexity of valid group pattern mining problem. We support the use of static method, which uses areas and sliding windows instead …

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Thermometric Measurements Of The Molecular Sublayer At The Air-Water Interface, B. Ward Apr 2006

Thermometric Measurements Of The Molecular Sublayer At The Air-Water Interface, B. Ward

OES Faculty Publications

[1] A series of measurements was conducted in the AirSea Interaction Saltwater Tank (ASIST) to study the response of the air-water interfacial molecular sublayer under various heat flux and wind speed conditions. In-situ gradients were measured with a platinum-plated tungsten wire microthermometer, which resolved the temperature of the thermally conductive sublayer. Air-sea heat flux was controlled by changing the air-water temperature difference (ΔTAW) and the wind speed, and measurements were made for three ΔTAW regimes over a range of wind speeds. A function was fitted to the measured temperature profiles as a way of extracting the boundary …

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Un Estudio De La Palma De Ramos, Ceroxylum Alpinum, En La Zona Intag, Ecuador, Lupe Moscoe Apr 2006

Un Estudio De La Palma De Ramos, Ceroxylum Alpinum, En La Zona Intag, Ecuador, Lupe Moscoe

Independent Study Project (ISP) Collection

This study addresses the endangered wax palm species, Ceroxylum alpinum, in the Ecuadorian cloud forest zone of Intag. Attention has recently arisen regarding this plant because the yellow-eared parrot, Ognorhynchus icterotis, which depends on it for food and nesting, is in critical danger of extinction. Much of this attention has targeted the use of wax palm fronds on Palm Sunday, but this investigation shows that this is only one of the many threats to the palm. Environmentalists in Intag are currently undertaking reforestation projects in community reserves to save the palm, but little is known about its development. This study …

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Effect Of Changing Requirements: A Tracking Mechanism For The Analysis Workflow, Subhajit Datta, Robert Van Engelen Apr 2006

Effect Of Changing Requirements: A Tracking Mechanism For The Analysis Workflow, Subhajit Datta, Robert Van Engelen

Research Collection School Of Computing and Information Systems

Managing the effects of changing requirements remains one of the greatest challenges of enterprise software development. The iterative and incremental model provides an expedient framework for addressing such concerns. This paper presents a set of metrics - Mutation Index, Component Set, Dependency Index - and a methodology to measure the effects of requirement changes in the analysis workflow from one iteration to another. Results from a sample case study are included to highlight a usage scenario. Future directions of our work based on this mechanism are also discussed.

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The Viscous Catenary, John Koulakis Apr 2006

The Viscous Catenary, John Koulakis

Pomona Senior Theses

Variational techniques are used to develop a theory for the time evolution of a thin strand of viscous fluid suspended from two points. The shape of the strand is approximated to be a parabola and energy conservation is used to derive a differential equation modeling the change in height over time. Data is collected with a high resolution camera and a strobe light to obtain the position and shape of the strand over multiple intervals of time. Three very different and unexpected types of behaviors are observed depending on the initial thickness and shape of the filament. The approximation fits …

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Getting More Out Of Two Asset Portfolios, Tom Arnold, Terry D. Nixon Apr 2006

Getting More Out Of Two Asset Portfolios, Tom Arnold, Terry D. Nixon

Finance Faculty Publications

Two-asset portfolio mathematics is a fixture in many introductory finance and investment courses. However, the actual development of the efficient frontier and capital market line are generally left to a heuristic discussion with diagrams. In this article, the mathematics for calculating these attributes of two-asset portfolios are introduced in a framework intended for the undergraduate classroom.

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Decision Modeling: Why Farmers Do Or Do Not Convert To Organic Farming, Ryan Locke Apr 2006

Decision Modeling: Why Farmers Do Or Do Not Convert To Organic Farming, Ryan Locke

Independent Study Project (ISP) Collection

This study examines why farmers in Northern New South Wales, Australia do or do not convert to organic farming from conventional farming practices. Organic agriculture provides a production alternative that may be environmentally and nutritionally beneficial. Because the structural settings of economy and society influence decision-making on an individual basis at the farm level, discussions of policy must consider why farmers do, or do not, convert to organic farming. Ultimately, the successfulness of a policy depends on the effectiveness of motivating individual action. A hierarchical decision tree was created using ethnographic decision tree modeling. Elimination criteria, motivational criteria, and constraints …

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Interpreting Nature In Australia Through Poetry: A Personal Anthology Written Within The Erosion Caldera Of Northern New South, Kyla Allon Apr 2006

Interpreting Nature In Australia Through Poetry: A Personal Anthology Written Within The Erosion Caldera Of Northern New South, Kyla Allon

Independent Study Project (ISP) Collection

My Independent Study Project (ISP) involved traveling within the erosion caldera of northern New South Wales, mainly WWOOFing (Willing Workers on Organic Farms) and writing environmental poetry about the places where I lived and worked. I began by researching past Australian environmental poets so that I could have a strong basic understanding before commencing my own writing. I lived in four different locations within the erosion caldera and strove to form a strong sense of place that is reflected in my poetry. Ultimately, I produced an anthology of poems that capture my responses to the natural environments that I experienced. …

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A Beautiful Mind, Christopher D. Goff Apr 2006

A Beautiful Mind, Christopher D. Goff

College of the Pacific Faculty Presentations

No abstract provided.

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Visualizing Paths In Context, Fabio Pellacini, Lori Lorigo, Geri Gay Apr 2006

Visualizing Paths In Context, Fabio Pellacini, Lori Lorigo, Geri Gay

Computer Science Technical Reports

Data about movement through a space is increasingly becoming available for capture and analysis. In many applications, this data is captured or modeled as transitions between a small number of areas of interests, or a finite set of states, and these transitions constitute paths in the space. Similarities and differences between paths are of great importance to such analyses, but can be difficult to assess. In this work we present a visualization approach for representing paths in context, where individual paths can be compared to other paths or to a group of paths. Our approach summarizes path behavior using a …

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