Optimizing Management Functions in Distributed Systems

With the increased availability and complexity of distributed systems comes a greater need for solutions to assist in the management of distributed systems. Despite the significant contributions made towards the development of management tools that monitor and control distributed systems, little has been done to address issues such as optimizing the execution of management functions with respect to system and management requirements. This paper presents a management optimization model in which management agents and managed objects are efficiently configured on the basis of a set of system and management requirements. We illustrate our model and describe its implementation through a Branch- and Bound-based algorithm and a web-based interface. The latter enables users to specify the requirements used by the optimization algorithm to determine efficient management configurations. It also includes an XML-based interface through which management agents can be started independent of the underlying platforms. Performance characteristics of the proposed algorithm as well as experimental results to illustrate the validity of the model are also described.     

An Equitable Bandwidth Allocation Model for Video-on-Demand Networks

Video-on-Demand (VOD) or near-VOD services are expected to grow significantly over time, providing diverse programs for home entertainment, learning and training, news-on-demand, and other applications. These services require large bandwidth resources. We present a model for bandwidth allocation in a tree network with limited link capacities, where a server at the root node repeatedly broadcasts copies of various programs. The time intervals between successive broadcasts of each program can be increased at subsequent nodes, or the video quality can be decreased, thus providing different service performance to different nodes while satisfying the capacity constraints. The model is formulated as an equitable resource allocation problem with a lexicographic minimax objective function and tree-like ordering constraints. We present a lexicographic minimax algorithm that allocates each link’s bandwidth among the programs carried on the link. The algorithm repeatedly solves minimax problems, and fixes some variables at their optimal value after the solution of each such problem. The algorithm for solving the minimax problems uses a bisection search to find the minimax solution with the minimal decision variable values. The model also provides an ordered list of links from the most critical link to the least critical link, a useful feature for capacity expansion planning decisions.     

Response of dryland wheat to small supplemental irrigation and fertilizer nitrogen in submontane Punjab

In northern India, the monsoon rains recede much earlier than the sowing time of post-rainy crops and the seed-zone gets dried. Excess rain water collected in near-farm or on-farm reservoirs permits small presowing and/or postsowing irrigation(s) to increase yield which is also limited by N supplies. Field experiments were conducted to match N application rates with available water supplies to optimise wheat (Triticum aestivum L.) yields. Five rates of fertilizer N (0, 25, 50, 75 and 100 kg ha^–1) were combined with five irrigation treatments (no-irrigation; 5 cm and 10 cm presowing irrigation, 5 cm irrigation 30 days after sowing and; equal presowing and postsowing irrigations totalling 10 cm). The yield was regressed over crop water supply inclusive of irrigation (W) or exclusive of irrigation (W₁) and applied nitrogen (N). Grain yield increased with increase in both water supply and N-rate. Within certain limits N and W₁ substituted each other for yield and so did irrigation and W₁. Irrespective of irrigation, the amount of N required to substitute for given W₁ to maintain a given yield decreased with increasing W₁. At low W₁, irrigation substituted for small changes in W₁ but with increased W₁, irrigation substituted for larger changes in W₁. Also with increase in N level given irrigation substituted for smaller amount of W₁. These regressions permit recommendations of N in relation to stored water and seasonal rain with or without limited irrigation. The latter was most useful at intermediate W₁.     

Cryptanalysis and improvement of ‘a secure authentication scheme for telecare medical information system’ with nonce verification

In 2009, Xu et al. presented an improved smartcard based authentication scheme while using a security model previously applied by Bellare et al. to prove the security of their authentication methods. Later on, in 2012, Wu et al. pointed out number of authentication attacks in Xu et al. scheme. To address these issues, Wu et al. presented a Smartcard based Two-Factor Authentication (2FA) scheme for Telecare Medical Information System (TMIS) facility. In this study, we prove that authentication scheme of Wu et al. is still vulnerable to impersonation attack, offline password guessing attack, forgery attack and many other attacks. Moreover, number of performance and verification issues are also outlined in the authentication scheme of Wu et al. To overcome these issues, an improved and enhanced 3FA Smartphone based authentication method is proposed on a Cloud Computing environment. The proposed scheme is further corroborated using Burrows-Abadi-Needham logic (BAN logic) nonce verification. The detailed BAN logic verification and further security analysis shows that the proposed authentication protocol is highly reliable and secure in terms of message verifications, message freshness and trustworthiness of its origin. Moreover, the comparative security, performance and feature analysis shows that the proposed work yields an even more improved and enhanced authentication framework as compared to Wu et al. authentication scheme.     

Design of CWDM multiplexers based on series coupled ring resonators: analysis, potential and prospects on MEMS fabrication technologies

New designs for a 1 × 4 and a 1 × 8 CWDM multiplexers based on cascaded groups of series coupled ring resonators (Little et al. in J Lightwave Technol 15:998–1005, 1997; IEEE Photon Technol Lett 10:2263–2265, 2004; Hryniewicz et al. in IEEE Photon Technol Lett 12:320–322, 2000) are presented. Compared to other integrated optical alternatives such as MMI phasars (Paiam and MacDonald in Appl Opt 36: 5097–5108, 1997), cascaded Mach–Zehnder interferometers (Wang and He in J Lightwave Technol 23:1284–1290, 2005) and cascaded AWG (Dragone in IEEE Photon Technol Lett 3:812–815, 1991; Uetsuka in IEEE J Sel Top Quant Electron 10:393–402, 2004), the proposed circuits offer superior performance in their very sharp roll-off factor that exceeds 0.75, their reduced crosstalk level that lies below −60 dB and their negligible insertion loss for the 1 × 4 design. For the 1 × 8 design, the worst case insertion loss is 4 dB. However, the performances obtained exhibit passband ripples in the order of 5 dB, and besides, they are not very tolerant to fabrication errors. Being designed for SOI technology, the proposed circuits are compact as the circuit areas are 130 × 130 and 90 × 150 μm² for the 1 × 4 and 1 × 8 designs, respectively. They also have a high potential for MEMS tunability.     

A New Efficient Block-Matching Algorithm for Motion Estimation

This paper presents a new full-search block-matching algorithm: Multi-stage Interval-based Motion Estimation algorithm (MIME). The proposed algorithm is a block based motion estimation algorithm that utilizes successive elimination technique. We define two approximate functions, as the upper and lower boundaries of the interval that includes the Conventional distortion metric SAD. Each stage in the proposed algorithm; except for the last stage; incorporates low resolution pixels for the boundary functions calculations. The final stage is a full resolution block matching stage. MIME has a high probability of finding the optimal motion vector at any stage of the algorithm. The proposed algorithm reduces the computational complexity by successively eliminating non-candidate blocks from the search window at each stage. This computational reduction leads to enhanced performance in terms of low power consumption and fast motion vector estimation. A low power VLSI implementation of the algorithm is also presented in this paper. Simulation results on benchmark video sequences shows that MIME algorithm eliminates almost 88% of the candidate blocks after only two interval based stages. Hanan Ahmed Hosny Mahmoud obtained the B.Sc. of Computer Science from Faculty of Engineering, University of Alexandria in 1986. She obtained her M.Sc. in Computer Science from Faculty of Engineering, University of Alexandria in 1991. She obtained the M.Sc. in Computer Engineering from University of Louisiana at Lafayette in 1999 and the Ph.D. in Computer Engineering from University of Louisiana at Lafayette in 2001. Currently, she is working as an Assistant Professor in the Faculty of Engineering, University of Alexandria. Sumeer Goel received the B. Tech degree in electronics and communications engineering from Punjab Technical University, Punjab, India, in 2001. He received the M.S. degree in computer engineering from University of Louisiana at Lafayette, Lafayette, LA, in 2003 where he is continuing his education towards Ph.D. degree in computer engineering. His research interests are low-power and high noise tolerance VLSI circuit and architecture design for digital signal processing applications. Mohsen Shaaban received his B.S. degree in electrical engineering and communications from the University of Alexandria, Egypt, in 1998. In 2001, he joined the University of Louisiana at Lafayette (ULL) as a teaching and research assistant at the Center For Advanced Computer Studies (CACS), the VLSI Research Lab. He received his M.S. degree in the field computer engineering from ULL in 2003. Currently, he is pursing his Ph.D. degree in the same field. His research interests include Digital VLSI circuit design, CAD tools and Video processing applications. Magdy A. Bayoumi received the B.Sc. and M.Sc. degrees in electrical engineering from Cairo University, Cairo, Egypt, in 1973 and 1977, the M.Sc. degree in computer engineering from Washington University in St. Louis, MO, in 1981, and the Ph.D. degree in electrical engineering from the University of Windsor, Windsor, ON, Canada, in 1984. Currently, he is the Director of the Center for Advanced Computer Studies (CACS), Department Head of the Computer Science Department, the Edmiston Professor of Computer Engineering, and the Lamson Professor of Computer Science at The Center for Advanced Computer Studies, University of Louisiana at Lafayette, where he has been a faculty member since 1985. He has edited and co-edited three books in the area of VLSI Signal Processing. He was an Associate Editor of the Circuits and Devices Magazine and is currently an Associate Editor of Integration, the VLSI Journal, and the Journal of VLSI Signal Processing Systems. He is a Regional Editor for the VLSI Design Journal and on the Advisory Board of the Journal on Microelectronics Systems Integration. He has one patent pending. His research interests include VLSI design methods and architectures, low power circuits and systems, digital signal processing architectures, parallel algorithm design, computer arithmetic, image and video signal processing, neural networks, and wideband network architectures. Dr. Bayoumi received the University of Louisiana at Lafayette 1988 Researcher of the Year Award and the 1993 Distinguished Professor Award. He was an Associate Editor of the IEEE CIRCUITS AND DEVICES MAGAZINE, the IEEE TRANSACTIONS ON VLSI SYSTEMS, the IEEE TRANSACTIONS ON NEURAL NETWORKS, and the IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS—II: ANALOG AND DIGITAL SIGNAL PROCESSING. From 1991 to 1994, he served on the Distinguished Visitors Program for the IEEE Computer Society, and he is on the Distinguished Lecture Program of the Circuits and Systems Society. He was the Vice President for the technical activities of the IEEE Circuits and Systems Society. He was the Co-chairman of the Workshop on Computer Architecture for Machine Perception in 1993, and is a member of the Steering Committee of this workshop. He was the General Chairman of the 1994 MWSCAS and is a member of the Steering Committee of this symposium. He was the General Chairman for the 8th Great Lake Symposium on VLSI in 1998. He has been on the Technical Program Committee for ISCAS for several years and he was the Publication Chair for ISCAS'99. He was also the General Chairman of the 2000 Workshop on Signal Processing Design and Implementation. He was a founding member of the VLSI Systems and Applications Technical Committee and was its Chairman. He is currently the Chairman of the Technical Committee on Circuits and Systems for Communication and the Technical Committee on Signal Processing Design and Implementation. He is a member of the Neural Network and the Multimedia Technology Technical Committees. Currently, he is the faculty advisor for the IEEE Computer Student Chapter at the University of Louisiana at Lafayette.     

SoftPOSIT: Simultaneous Pose and Correspondence Determination

The problem of pose estimation arises in many areas of computer vision, including object recognition, object tracking, site inspection and updating, and autonomous navigation when scene models are available. We present a new algorithm, called SoftPOSIT, for determining the pose of a 3D object from a single 2D image when correspondences between object points and image points are not known. The algorithm combines the iterative softassign algorithm (Gold and Rangarajan, 1996; Gold et al., 1998) for computing correspondences and the iterative POSIT algorithm (DeMenthon and Davis, 1995) for computing object pose under a full-perspective camera model. Our algorithm, unlike most previous algorithms for pose determination, does not have to hypothesize small sets of matches and then verify the remaining image points. Instead, all possible matches are treated identically throughout the search for an optimal pose. The performance of the algorithm is extensively evaluated in Monte Carlo simulations on synthetic data under a variety of levels of clutter, occlusion, and image noise. These tests show that the algorithm performs well in a variety of difficult scenarios, and empirical evidence suggests that the algorithm has an asymptotic run-time complexity that is better than previous methods by a factor of the number of image points. The algorithm is being applied to a number of practical autonomous vehicle navigation problems including the registration of 3D architectural models of a city to images, and the docking of small robots onto larger robots.     

A region-segmentation combining surrogate model based on L-indicator and N-fold cross-validation technique

For complex engineering problems, for which the mathematical models may be linear, low-order nonlinear or even high-order nonlinear, surrogate models which have high adaptability and accuracy are required. This article develops a method for constructing a region-segmentation combining surrogate model. It is based on the idea that in the entire experimental domain, different local regions may present different characteristics (linearity, low-order nonlinearity and high-order nonlinearity), and the entire domain should be divided into several subregions to be approximated by different surrogates so as to achieve high prediction accuracy in local regions. The preferred models in each subregion then constitute a weight-average combining surrogate model. The investigations reveal that the new model not only is more adaptive to analytically unknown functions, but also gives more accurate predictions. The method has been applied to three benchmark problems and a practical engineering problem, and the results maintain validity.     

Dual-wavelength all-fiber Q-switched fiber laser using bismuth-doped fiber as saturable absorber

A passively Q-switched all-fiber laser is demonstrated using a 10-cm-long bismuth-doped fiber (BDF) as a saturable absorber (SA). The dual-wavelength operation was obtained due to the nonlinear effect inside the fabricated BDF, which has a high germanium content. Stable Q-switched pulses were obtained at the dual synchronous wavelengths of 1 530.1 nm and 1 531.1 nm. When the pump power is tuned from 105.3 mW to 191.0 mW, the repetition rate can be varied from 82.6 kMz to 117.6 kHz. The maximum pulse energy and average output power were 83.4 nJ and 9.8 mW, respectively while the minimum pulse width was 8.5 μs at the maximum pump power of 191.0 mW. Our results indicate that BDF could be a promising alternative optical modulator for pulsed fiber laser application.