Adaptation of Single-user Multi-touch Components to Support Synchronous Mobile Collaboration

Mobile applications, which include calendars, browsers, and interactive maps, are part of our lives nowadays. Most mobile applications are single user; and they do not enable synchronous collaboration among the users. Mobile collaboration enables multiple users in diverse locations to combine synergistically their contributions in a convenient manner. We investigate the potential to create collaborative applications based on existing single user mobile applications. In this work, we propose an adaptation technique based on the reuse of manufacturers’ SDKs (Software Development Kits) to create multi-user prototype applications. In general, adaptation is made manually; nonetheless, we conjecture that some automation is possible. This paper investigates this possibility. More specifically, we hypothesize that if the target SDK’s components of mobile applications comply with certain design guidelines, automatic adaption can be enhanced. We present a reference model and an automatic process to develop high-fidelity prototype multi-user mobile applications by the conversion of multi-touch user interface found on single-user applications. We discuss two examples that illustrate our proposal and provide a quantitative Lines of Code (LOC) comparison of existing approaches.     

ViewStation applications: implications for network traffic

This paper describes applications built on the ViewStation, a distributed multimedia system based on Unix workstations and a gigabit per second local area network. A key tenet of the ViewStation project is the delivery of media data not just to the desktop but all the way to the application program. As processing power continues to improve, our approach enables applications that perform intensive processing of audio and video data. We hypothesize that as media data are shaped by this software-based processing, the resultant network traffic patterns will be dominated more by software behavior than by so-called real-time issues. We have written applications that directly process live video to provide more responsive human-computer interaction. We have also developed applications to explore the potential of media processing to support content-based retrieval of prerecorded television broadcasts. These applications perform intelligent processing on video, as well as straightforward presentation. They demonstrate the utility of network-based multimedia systems that deliver audio and video data all the way to the application. The network requirements of the applications are modeled as a combination of bursty transfers and periodic packet-trains     

Utilizing the power of high-performance computing

The main focus of this article is the design of embedded signal processing (ESP) application software. We identify the characteristics of such applications in terms of their computational requirements, data layouts, and latency and throughput constraints. We describe an ESP application, an adaptive sonar beamformer. Then, we briefly survey the state-of-the-art in high performance computing (HPC) technology and address the advantages and challenges in using HPC technology for implementing ESP applications. To describe the software design issues in this context, we define a task model to capture the features of ESP applications. This model specifies the independent activities in each processing stage. We also identify various optimization problems in parallelizing ESP applications. We address the key issues in developing scalable and portable algorithms for ESP applications. We focus on the algorithmic issues in exploiting coarse-grain parallelism. These issues include data layout design and task mapping. We show a task mapping methodology for application software development based on our execution model (Lee et al., 1998). This uses a novel stage partitioning technique to exploit the independent activities in a processing stage. We use our methodology to maximize the throughput of an ESP application for a given platform size. The resulting application software using this methodology is called a software task pipeline. An adaptive sonar beamformer has been implemented using this design methodology     

Mobile Commerce: Framework,Applications and Networking Support

Advances in e-commerce have resulted in significant progress towards strategies, requirements, and development of e-commerce applications. However, nearly all e-commerce applications envisioned and developed so far assume fixed or stationary users with wired infrastructure. We envision many new e-commerce applications that will be possible and significantly benefit from emerging wireless and mobile networks. To allow designers, developers, and researchers to strategize and create mobile commerce applications, we propose a four-level integrated framework for mobile commerce. Since there are potentially an unlimited number of mobile commerce applications, we attempt to identify several important classes of applications such as mobile financial applications, mobile inventory management, proactive service management, product location and search, and wireless re-engineering. We discuss how to successfully define, architect, and implement the necessary hardware/software infrastructure in support of mobile commerce. Also, to make mobile commerce applications a reality, we address networking requirements, discuss support from wireless carriers, and present some open research problems.     

Vehicle Ad Hoc networks: applications and related technical issues

This article presents a comprehensive survey of the state-of-the-art for vehicle ad hoc networks. We start by reviewing the possible applications that can be used in VANETs, namely, safety and user applications, and by identifying their requirements. Then, we classify the solutions proposed in the literature according to their location in the open system interconnection reference model and their relationship to safety or user applications. We analyze their advantages and shortcomings and provide our suggestions for a better approach. We also describe the different methods used to simulate and evaluate the proposed solutions. Finally, we conclude with suggestions for a general architecture that can form the basis for a practical VANET.     

Hardware-software partitioning and pipelined scheduling of transformative applications

Transformative applications are computation intensive applications characterized by iterative dataflow behavior. Typical examples are image processing applications like JPEG, MPEG, etc. The performance of embedded hardware-software systems that implement transformative applications can be maximized by obtaining a pipelined design. We present a tool for hardware-software partitioning and pipelined scheduling of transformative applications. The tool uses iterative partitioning and pipelined scheduling to obtain optimal partitions that satisfy the timing and area constraints. The partitioner uses a branch and bound approach with a unique objective function that minimizes the initiation interval of the final design. We present techniques for generation of good initial solution and search-space limitation for the branch and bound algorithm. A candidate partition is evaluated by generating its pipelined schedule. The scheduler uses a novel retiming heuristic that optimizes the initiation interval, number of pipeline stages, and memory requirements of the particular design alternative. We evaluate the performance of the retiming heuristic by comparing it with an existing technique. The effectiveness of the entire tool is demonstrated by a case study of the JPEG image compression algorithm. We also evaluate the run time and design quality of the tool by experimentation with synthetic graphs.     

Manageability of Java-based digital TV receivers

The hardest problems of network management are frequently not modeling, abstracting, filtering, or propagation of management information; they are the extraction of management information from the resources being managed. This process is commonly referred to as the management instrumentation of resources. Although a variety of new systems are being designed and deployed on a continuous basis, it is still a rare occasion that these systems are designed and instrumented to be managed. We show how management instrumentation can be simply and powerfully accomplished if management provisions are made in the design of the managed resource. We look at digital television receivers and their Java applications as standardized by the Advanced Television Standards Committee (ATSC). We model the applications lifecycle of these applications using the ITU-T X.731 State Management function, and outline the corresponding applications and management Java APIs     

Downlink user selection and resource allocation for semi-elastic flows in an OFDM cell

We are concerned with user selection and resource allocation in wireless networks for semi-elastic applications such as video conferencing. While many packet scheduling algorithms have been proposed for elastic applications, and many user selection algorithms have been proposed for inelastic applications, little is known about optimal user selection and resource allocation for semi-elastic applications in wireless networks. We consider user selection and allocation of downlink transmission power and subcarriers in an orthogonal frequency division multiplexing cellular system. We pose a utility maximization problem, but find that direct solution is computationally intractable. We first propose a method that makes joint decisions about user selection and resource allocation by transforming the utility function into a concave function so that convex optimization techniques can be used, resulting in a complexity polynomial in the number of users with a bounded duality gap. This method can be implemented if the network communicates a shadow price for power to power allocation modules, which in turn communicate shadow prices for rate to individual users. We then propose a method that makes separate decisions about user selection and resource allocation, resulting in a complexity linear in the number of users.     

A comparison of sender-initiated and receiver-initiated reliablemulticast protocols

Sender-initiated reliable multicast protocols based on the use of positive acknowledgments (ACKs) can suffer performance degradation as the number of receivers increases. This degradation is due to the fact that the sender must bear much of the complexity associated with reliable data transfer (e.g., maintaining state information and timers for each of the receivers and responding to receivers' ACKs). A potential solution to this problem is to shift the burden of providing reliable data transfer to the receivers-thus resulting in receiver-initiated multicast error control protocols based on the use of negative acknowledgments (NAKs). We determine the maximum throughputs for generic sender-initiated and receiver-initiated protocols for two classes of applications: (1) one-many applications where one participant sends data to a set of receivers and (2) many-many applications where all participants simultaneously send and receive data to/from each other. We show that a receiver-initiated error control protocol which requires receivers to transmit NAKs point-to-point to the sender provides higher throughput than a sender-initiated counterpart for both classes of applications. We further demonstrate that, in the case of a one many application, replacing point-to-point transfer of NAKs with multicasting of NAKs coupled with a random backoff procedure provides a substantial additional increase in the throughput of a receiver-initiated error control protocol over a sender-initiated protocol. We also find, however, that such a modification leads to a throughput degradation in the case of many-many applications     

Resource sharing for replicated synchronous groupware

We describe problems associated with accessing data resources external to the application, which we term externalities, in replicated synchronous collaborative applications. Accessing externalities such as files, databases, network connections, environment variables, and the system clock is not as straightforward in replicated collaborative software as in single-user applications or centralized collaborative systems. We describe ad hoc solutions that add to development cost and complexity because the developer must program different behavior for different replicas. We introduce a novel general approach to accessing externalities uniformly in a replicated collaborative system. The approach uses a semireplicated architecture where the actual externality resides at a single location and is accessed via replicated proxies. This approach allows developers of replicated synchronous groupware to (1) use similar externality access mechanisms as in traditional single-user applications, and (2) program all replicas to execute the same behavior. We describe a general design for proxied access to read-only, write-only, and read-write externalities and discuss the tradeoffs of this semireplicated approach over full, literal replication and the class of applications to which this approach can be successfully applied. We also describe details of a prototype implementation of this approach within a replicated collaboration-transparency system, called Flexible JAMM (Java Applets Made Multiuser)     

An architecture and a dynamic scheduling algorithm of grid for providing security for real‐time data‐intensive applications

Real‐time data‐intensive applications with security concerns are arising in many disciplines of science and engineering. Scheduling algorithms play an important role in the design of real‐time data‐intensive applications. However, conventional real‐time scheduling algorithms are inappropriate to fulfill the security requirements of real‐time data‐intensive applications. In this paper we have proposed a security‐attentive dynamic real‐time scheduling algorithm named SARDIG for scheduling real‐time data‐intensive applications. We have proposed a grid architecture which describes the scheduling framework of real‐time data‐intensive applications. In addition, we have introduced a mathematical model for providing security of the real‐time data‐intensive applications and a security gain function to quantitatively measure the security enhancement for applications running in the grid sites. We have also proved that the SARDIG algorithm always provides optimum security for real‐time data‐intensive applications. The time complexity of the SARDIG algorithm has been analyzed to show the efficiency of the algorithm. Simulation results show that the SARDIG algorithm provides better performance and security than other existing scheduling algorithms. Copyright © 2011 John Wiley & Sons, Ltd.     

Serial dark soliton for 100-gb/s applications

We analyze the performance through numerical simulations of a new modulation format: serial dark soliton (SDS) for wide-area 100-Gb/s applications. We compare the performance of the SDS with conventional dark soliton, amplitude-modulation phase-shift keying (also known as duobinary), nonreturn-to-zero, and return-to-zero modulation formats, when subjected to typical wide-area-network impairments. We show that the SDS has a strong chromatic dispersion and polarization-mode-dispersion tolerance, while maintaining a compact spectrum suitable for strong filtering requirement in ultradense wavelength-division-multiplexing applications. The SDS can be generated using commercially available components for 40-Gb/s applications and is cost efficient when compared with other 100-Gb/s electrical-time-division-multiplexing systems.     

Laser radar in robotics

In this paper we describe the basic operating principles of laser radar sensors and the typical algorithms used to process laser radar imagery for robotic applications. We review 12 laser radar sensors to illustrate the variety of systems that have been applied to robotic applications wherein information extracted from the laser radar data is used to automatically control a mechanism or process. Next we describe selected robotic applications in seven areas: autonomous vehicle navigation, walking machine foot placement, automated service vehicles, manufacturing and inspection, automotive, military and agriculture. We conclude with a discussion of the status of laser radar technology and suggest trends we see in the application of laser radar sensors to robotics. Many new applications are expected as the maturity level progresses and system costs are reduced     

OCDMA and Optical Coding: Principles, Applications, and Challenges [Topics in Optical Communications]

We survey the current trends in OCDMA and optical coding through their applications. Although a prerequisite for OCDMA, optical coding distinguishes itself from OCDMA through major applications where codes are not applied to data and carry network-level information other than user identity. After introducing the principles of coding, we discuss OCDMA and its applications, particularly OCDMA PON. Optical coding and its applications are then reviewed.     

Providing application-level QoS in 3G/4G wireless systems: a comprehensive framework based on multirate CDMA

The emerging applications for 3G and 4G wireless systems typically require highly heterogeneous and time-varying quality of service from the underlying protocol layers. The wireless links, however, provide only an unreliable communication channel that suffers from temporal outages. As a consequence, protocol mechanisms are needed that, based on the unreliable wireless links, provide the different service qualities required by the emerging applications. We identify the emerging IP-based applications for 3G and 4G wireless systems and categorize their QoS requirements. We discuss the wireless access mechanisms that show promise as the basis for supporting these applications. We then propose a set of protocol mechanisms that, based on the discussed wireless access mechanisms, provide the required QoS for the different application categories.     

Combining static and dynamic array detection for binary synthesis with multiple memory ports

In High-Level Synthesis, Binary Synthesis is a method for synthesizing compiled applications for which the source code is not available. One of the advantages of FPGAs over processors is the availability of multiple internal and external memory banks. Binary synthesis tools use multiple memory banks if they are able to recover data-structures from the binary. In this work we improve the recovery of data-structures by introducing dynamic memory analysis and combining it with improved static memory analysis. We show that many applications can only be synthesized using dynamic memory analysis. We present two FPGA based architectures for implementing the bound-checking and recovery for the synthesized code. Our experiments show that the proposed technique accelerates the execution of applications which use multiple memory banks concurrently. We demonstrate that many binary applications indeed benefit from this technique.     

Markov decision process (MDP) framework for software power optimization using call profiles on mobile phones

We present an optimization framework for delay-tolerant data applications on mobile phones based on the Markov decision process (MDP). This process maximizes an application specific reward or utility metric, specified by the user, while still meeting a talk-time constraint, under limited resources such as battery life. This approach is novel for two reasons. First, it is user profile driven, which means that the user’s history is an input to help predict and reserve resources for future talk-time. It is also dynamic: an application will adapt its behavior to current phone conditions such as battery level or time before the next recharge period. We propose efficient techniques to solve the optimization problem based on dynamic programming and illustrate how it can be used to optimize realistic applications. We also present a heuristic based on the MDP framework that performs well and is highly scalable for multiple applications. This approach is demonstrated using two applications: Email and Twitter synchronization with different priorities. We present experimental results based on Google’s Android platform running on an Android Develepor Phone 1 (HTC Dream) mobile phone.     

A LP-RR principle-based admission control for a mobile network

In mobile networks, the traffic fluctuation is unpredictable due to mobility and varying resource requirement of multimedia applications. Hence, it is essential to maintain traffic within the network capacity to provide service guarantees to running applications. This paper proposes an admission control (AC) scheme in a mobile cellular environment supporting hand-off and new application traffic. In the case of multimedia applications, each applications has its own distinct range of acceptable quality of service (QoS) requirements. The network provides the service by maintaining the application specified QoS range. We propose a linear programming resource reduction (LP-RR) principle for admission control by maintaining QoS guarantees to existing applications and to increase the percentage of admission to hand-off and new applications. Artificial neural networks are used to solve the linear programming problem, which facilitates in real time admission control decision in the practical systems. We present an analytical model and results for the proposed AC scheme with resource reduction principle and a simulation study of the AC for performance evaluation. The simulation results demonstrate that the proposed AC scheme performs well in terms of increasing the number of admitted applications and maintains higher percentage of resource utilization. The suggested principle also shown that it is appropriate for the fair resource allocation with improved resource utilization.