Data Mining Practical Machine Learning Tools and Techniques

It is shown that, particularly for terrestrial cellular telephony, the interference-suppression feature of CDMA (code division multiple access) can result in a many-fold increase in capacity over analog and even over competing digital techniques. A single-cell system, such as a hubbed satellite network, is addressed, and the basic expression for capacity is developed. The corresponding expressions for a multiple-cell system are derived. and the distribution on the number of users supportable per cell is determined. It is concluded that properly augmented and power-controlled multiple-cell CDMA promises a quantum increase in current cellular capacity. >

On the capacity of a cellular CDMA system

Praise for the Third Edition: "This is one of the best books available. Its excellent organizational structure allows quick reference to specific models and its clear presentation . . . solidifies the understanding of the concepts being presented."IIE Transactions on Operations EngineeringThoroughly revised and expanded to reflect the latest developments in the field, Fundamentals of Queueing Theory, Fourth Edition continues to present the basic statistical principles that are necessary to analyze the probabilistic nature of queues. Rather than presenting a narrow focus on the subject, this update illustrates the wide-reaching, fundamental concepts in queueing theory and its applications to diverse areas such as computer science, engineering, business, and operations research.This update takes a numerical approach to understanding and making probable estimations relating to queues, with a comprehensive outline of simple and more advanced queueing models. Newly featured topics of the Fourth Edition include:Retrial queuesApproximations for queueing networksNumerical inversion of transformsDetermining the appropriate number of servers to balance quality and cost of serviceEach chapter provides a self-contained presentation of key concepts and formulae, allowing readers to work with each section independently, while a summary table at the end of the book outlines the types of queues that have been discussed and their results. In addition, two new appendices have been added, discussing transforms and generating functions as well as the fundamentals of differential and difference equations. New examples are now included along with problems that incorporate QtsPlus software, which is freely available via the book's related Web site.With its accessible style and wealth of real-world examples, Fundamentals of Queueing Theory, Fourth Edition is an ideal book for courses on queueing theory at the upper-undergraduate and graduate levels. It is also a valuable resource for researchers and practitioners who analyze congestion in the fields of telecommunications, transportation, aviation, and management science.

Fundamentals of Queueing Theory

In this paper, we define and explore proofs of retrievability (PORs). A POR scheme enables an archive or back-up service (prover) to produce a concise proof that a user (verifier) can retrieve a target file F, that is, that the archive retains and reliably transmits file data sufficient for the user to recover F in its entirety.A POR may be viewed as a kind of cryptographic proof of knowledge (POK), but one specially designed to handle a large file (or bitstring) F. We explore POR protocols here in which the communication costs, number of memory accesses for the prover, and storage requirements of the user (verifier) are small parameters essentially independent of the length of F. In addition to proposing new, practical POR constructions, we explore implementation considerations and optimizations that bear on previously explored, related schemes.In a POR, unlike a POK, neither the prover nor the verifier need actually have knowledge of F. PORs give rise to a new and unusual security definition whose formulation is another contribution of our work.We view PORs as an important tool for semi-trusted online archives. Existing cryptographic techniques help users ensure the privacy and integrity of files they retrieve. It is also natural, however, for users to want to verify that archives do not delete or modify files prior to retrieval. The goal of a POR is to accomplish these checks without users having to download the files themselves. A POR can also provide quality-of-service guarantees, i.e., show that a file is retrievable within a certain time bound.

PORs: Proofs of Retrievability for Large Files

Traditional engineering instruction is deductive, beginning with theories and progressing to the applications of those theories Alternative teaching approaches are more inductive Topics are introduced by presenting specific observations, case studies or problems, and theories are taught or the students are helped to discover them only after the need to know them has been established This study reviews several of the most commonly used inductive teaching methods, including inquiry learning, problem-based learning, project-based learning, case-based teaching, discovery learning, and just-in-time teaching The paper defines each method, highlights commonalities and specific differences, and reviews research on the effectiveness of the methods While the strength of the evidence varies from one method to another, inductive methods are consistently found to be at least equal to, and in general more effective than, traditional deductive methods for achieving a broad range of learning outcomes

Inductive Teaching and Learning Methods: Definitions, Comparisons, and Research Bases

Adaptive resource allocation for multimedia quality of service (QoS) support in broadband wireless networks is examined in this work. A service model consisting of three service classes with different handoff-dropping requirements is presented. Appropriate call-admission control and resource-reservation schemes are developed to allocate resources adaptively to the real-time service classes with a stringent delay bound. Moreover, we propose an effective and efficient measurement-based dynamic resource allocation scheme to meet the target handoff-dropping probability. The nonreal-time applications, serviced by the best-effort model, are supported. The system accommodates adaptive multimedia applications to further reduce the blocking and dropping probabilities of real-time applications. Based on a multidimensional model analysis, simulations are conducted to evaluate the system performance. The simulation results show that the proposed system can satisfy the desired QoS of multimedia applications under different traffic loads, while achieving high utilization.

Adaptive resource allocation for multimedia QoS management in wireless networks

Cloud Computing has become a well-known primitive nowadays; many researchers and companies are embracing this fascinating technology with feverish haste. In the meantime, security and privacy challenges are brought forward while the number of cloud storage user increases expeditiously. In this work, we conduct an in-depth survey on recent research activities of cloud storage security in association with cloud computing. After an overview of the cloud storage system and its security problem, we focus on the key security requirement triad, i.e., data integrity, data confidentiality, and availability. For each of the three security objectives, we discuss the new unique challenges faced by the cloud storage services, summarize key issues discussed in the current literature, examine, and compare the existing and emerging approaches proposed to meet those new challenges, and point out possible extensions and futuristic research opportunities. The goal of our paper is to provide a state-of-the-art knowledge to new researchers who would like to join this exciting new field.

Survey on securing data storage in the cloud

The spectral shift response of optical whispering-gallery modes due to the adsorption and desorption of water molecules into a SiO2 nano-coating is investigated. This coating is applied to a silica microsphere and optical-shift measurements are made at a very low humidity level (<10%). The micro-optical coupling system is incorporated into a sealed vacuum chamber for controlled humidity testing. The experimental observation of the whispering-gallery-mode spectral shift with refractive index is consistent with a theoretical analysis using Mie theory. A significant hysteresis effect is observed in the spectral shift of individual whispering-gallery modes during variable humidity tests. To understand the hysteresis mechanism, tests with step changes in humidity are performed, which reveal complex and dynamic water molecule transport phenomena between the nano-coating and surrounding environment.

Spectral shift response of optical whispering-gallery modes due to water vapor adsorption and desorption

Mobile media streaming is envisioned to become an important service over packet-switched 2.5G and 3G wireless networks. At the same time, TCP-friendly rate-adaptation behavior for streaming will become an important IETF requirement. In this paper we investigate TCP-friendly on-demand streaming over wired and wireless links. We consider two approaches for achieving TCP-friendliness: first, by tunneling RTP packets over TCP and secondly by employing an RTP server rate control which does not exceed a variable rate constraint derived from the recently developed TFRC protocol. To allow a reasonable fair comparison between TCP and TFRC, we assume a simple retransmission mechanism on top of TFRC. We consider streaming from a server in the public Internet to both wired and wireless clients. For the wireless case we assumed a client which is connected to the public Internet via a dedicated 64 kbps WCDMA streaming bearer. Simulation results carried out in ns-2 show that TCP and TFRC can not fully utilize the WCDMA bearer at 5% packet loss rate over the shared public Internet link. Smooth playout of a typical 64 kbps video stream would require high initial buffering delays (>10 seconds) and large receiver buffer sizes (>60 KB). We finally investigate the gains from a proxy that splits the connection and uses TCP-friendly congestion control only over the shared part of the client-server connection. Simulation results show improvements in average throughput and wireless link utilization. By employing appropriate packet re-scheduling mechanisms, the initial buffering delay and the client buffer size for a typical 64 kbps video stream can be decreased by a factor of three to four.

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Proxy-based TCP-friendly streaming over mobile networks

This paper investigates computationally efficient suboptimal dynamic code assignment (DCA) schemes with call admission control (CAC) for orthogonal variable spreading factor code-division multiple-access systems. We examine two different approaches. The first approach reduces the complexity of the DCA scheme by partitioning the total resource (either capacity or service class) into several mutually exclusive subsets and assigns each subset of resource to a group of users in proportion to the corresponding traffic load. The second approach reduces the complexity of the optimal CAC scheme with the Markov decision process over an infinite time horizon by a suboptimal CAC policy, which is designed by observing the behavior of system dynamics over only two consecutive stages upon the arrival of a call. It is demonstrated by numerical evaluation that the proposed schemes achieve an average data throughput close to that of the optimal DCA-CAC performance while demanding a much lower computational complexity in their design and implementation.

/pdf/computationally-efficient-dynamic-code-assignment-schemes-34gvq86e7e.pdf

Lei Huang

Papers

Adaptive resource allocation for multimedia QoS management in wireless networks

Survey on securing data storage in the cloud

Spectral shift response of optical whispering-gallery modes due to water vapor adsorption and desorption

Proxy-based TCP-friendly streaming over mobile networks

Computationally Efficient Dynamic Code Assignment Schemes With Call Admission Control (DCA-CAC) for OVSF-CDMA Systems