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Articles 1 - 11 of 11

Full-Text Articles in Physical Sciences and Mathematics

On Static And Dynamic Partitioning Behavior Of Large-Scale Networks, Zhongmei Yao, Derek Leonard, Xiaoming Wang, Dmitri Loguinov Dec 2008

On Static And Dynamic Partitioning Behavior Of Large-Scale Networks, Zhongmei Yao, Derek Leonard, Xiaoming Wang, Dmitri Loguinov

Computer Science Faculty Publications

In this paper, we analyze the problem of network disconnection in the context of large-scale P2P networks and understand how both static and dynamic patterns of node failure affect the resilience of such graphs. We start by applying classical results from random graph theory to show that a large variety of deterministic and random P2P graphs almost surely (i.e., with probability 1 − o(1)) remain connected under random failure if and only if they have no isolated nodes. This simple, yet powerful, result subsequently allows us to derive in closed-form the probability that a P2P network develops isolated nodes, and …


Inside Unlv, Shane Bevell, Tony Allen, Karen Sharp, Mamie Peers, Cate Weeks Nov 2008

Inside Unlv, Shane Bevell, Tony Allen, Karen Sharp, Mamie Peers, Cate Weeks

Inside UNLV

No abstract provided.


Optimizing Product Line Designs: Efficient Methods And Comparisons, Alexandre Belloni, Robert Freund, Matthew Selove, Duncan Simester Jul 2008

Optimizing Product Line Designs: Efficient Methods And Comparisons, Alexandre Belloni, Robert Freund, Matthew Selove, Duncan Simester

Business Faculty Articles and Research

We take advantage of recent advances in optimization methods and computer hardware to identify globally optimal solutions of product line design problems that are too large for complete enumeration. We then use this guarantee of global optimality to benchmark the performance of more practical heuristic methods. We use two sources of data: (1) a conjoint study previously conducted for a real product line design problem, and (2) simulated problems of various sizes. For both data sources, several of the heuristic methods consistently find optimal or near-optimal solutions, including simulated annealing, divide-and-conquer, product-swapping, and genetic algorithms.


Link Lifetimes And Randomized Neighbor Selection In Dhts, Zhongmei Yao, Dmitri Loguinov Apr 2008

Link Lifetimes And Randomized Neighbor Selection In Dhts, Zhongmei Yao, Dmitri Loguinov

Computer Science Faculty Publications

Several models of user churn, resilience, and link lifetime have recently appeared in the literature [12], [13], [34], [35]; however, these results do not directly apply to classical Distributed Hash Tables (DHTs) in which neighbor replacement occurs not only when current users die, but also when new user arrive into the system, and where replacement choices are often restricted to the successor of the failed zone in the DHT space. To understand neighbor churn in such networks, this paper proposes a simple, yet accurate, model for capturing link dynamics in structured P2P systems and obtains the distribution of link lifetimes …


Symbolic Links In The Open Directory Project, Saverio Perugini Mar 2008

Symbolic Links In The Open Directory Project, Saverio Perugini

Computer Science Faculty Publications

We present a study to develop an improved understanding of symbolic links in web directories. A symbolic link is a hyperlink that makes a directed connection from a web page along one path through a directory to a page along another path. While symbolic links are ubiquitous in web directories such as Yahoo!, they are under-studied, and as a result, their uses are poorly understood. A cursory analysis of symbolic links reveals multiple uses: to provide navigational shortcuts deeper into a directory, backlinks to more general categories, and multiclassification. We investigated these uses in the Open Directory Project (ODP), the …


Volume And Cost Implications Of Product Portfolio Complexity, Mark A. Jacobs Jan 2008

Volume And Cost Implications Of Product Portfolio Complexity, Mark A. Jacobs

MIS/OM/DS Faculty Publications

Business leaders are concerned about the impacts of increasing levels of product portfolio complexity since many sense that complexity related costs such as order management, procurement, and inventory threaten to undermine operational efficiencies and consume profits. Even so, managers do not fully understand the extent and breadth of the impacts of product portfolio complexity. A more complete understanding of the operational effects of product portfolio complexity is lacking partially because researchers have not yet offered a robust theoretical perspective or studied it in a focused controlled way; until now. Herein, measures of product portfolio complexity are developed and related to …


Functorial Coalgebraic Logic: The Case Of Many-Sorted Varieties, Alexander Kurz, Daniela Petrişan Jan 2008

Functorial Coalgebraic Logic: The Case Of Many-Sorted Varieties, Alexander Kurz, Daniela Petrişan

Engineering Faculty Articles and Research

Following earlier work, a modal logic for T-coalgebras is a functor L on a suitable variety. Syntax and proof system of the logic are given by presentations of the functor. This paper makes two contributions. First, a previous result characterizing those functors that have presentations is generalized from endofunctors on one-sorted varieties to functors between many-sorted varieties. This yields an equational logic for the presheaf semantics of higher-order abstract syntax. As another application, we show how the move to functors between many-sorted varieties allows to modularly combine syntax and proof systems of different logics. Second, we show how to associate …


Tunable True-Time Delay Unit Based On Opto-Vlsi Processing, Feng Xiao, Budi Juswardy, Kamal Alameh Jan 2008

Tunable True-Time Delay Unit Based On Opto-Vlsi Processing, Feng Xiao, Budi Juswardy, Kamal Alameh

Research outputs pre 2011

A novel tunable true-time delay unit is proposed and demonstrated. The unit is based on the use of an Opto-VLSI processor that dynamically selects a single waveband or multiple wavebands from an RF-modulated broadband optical signal and routes them to a high-dispersion fiber for arbitrary time delay synthesis. Experimental results demonstrate continuously tunable time delay of up to 4 ns.


Integrated True-Time Delay Unit For Broadband Inteference Nulling In Phased-Array Antenna, Budi Juswardy, Kamal Alameh Jan 2008

Integrated True-Time Delay Unit For Broadband Inteference Nulling In Phased-Array Antenna, Budi Juswardy, Kamal Alameh

Research outputs pre 2011

This paper discusses an integrated true-time delay generation unit based on microminiaturisation of photonic and electronic components. The design, simulation, and performance of important building blocks for implementing a true-time delay-based phased-array antenna are presented.


Tunable Photonic Rf Signal Processor Using Opto-Vlsi, Budi Juswardy, Feng Xiao, Kamal Alameh Jan 2008

Tunable Photonic Rf Signal Processor Using Opto-Vlsi, Budi Juswardy, Feng Xiao, Kamal Alameh

Research outputs pre 2011

A tunable photonic RF signal processor is proposed and demonstrated. The filter structure comprises a reconfigurable Opto-VLSI processor for tunability, arrayed waveguide gratings for wavelength slicing and multiplexing, a custom-made fiber array for wavelength routing and dropping, and high-dispersion fibres for true-time delay generation. The processor structure enables positive and negative weights to be synthesised thus realising arbitrary responses. The proof-of-concept of the tunable photonic RF signal processor is experimentally demonstrated.


Set Linear Algebra And Set Fuzzy Linear Algebra, Florentin Smarandache, W.B. Vasantha Kandasamy, K. Ilanthenral Jan 2008

Set Linear Algebra And Set Fuzzy Linear Algebra, Florentin Smarandache, W.B. Vasantha Kandasamy, K. Ilanthenral

Branch Mathematics and Statistics Faculty and Staff Publications

In this book, the authors define the new notion of set vector spaces which is the most generalized form of vector spaces. Set vector spaces make use of the least number of algebraic operations, therefore, even a non-mathematician is comfortable working with it. It is with the passage of time, that we can think of set linear algebras as a paradigm shift from linear algebras. Here, the authors have also given the fuzzy parallels of these new classes of set linear algebras. This book abounds with examples to enable the reader to understand these new concepts easily. Laborious theorems and …