Throughput-Distortion Computation Of Generic Matrix Multiplication: Toward A Computation Channel For Digital Signal Processing Systems

The generic matrix multiply (GEMM) function is the core element of high-performance linear algebra libraries used in many computationally-demanding digital signal processing (DSP) systems. We propose an acceleration technique for GEMM based on dynamically adjusting the imprecision (distortion) of computation. Our technique employs adaptive scalar companding and rounding to input matrix blocks followed by two forms of packing in floating-point that allow for concurrent calculation of multiple results. Since the adaptive companding process controls the increase of concurrency (via packing), the increase in processing throughput (and the corresponding increase in distortion) depends on the input data statistics. To demonstrate this, we derive the optimal throughput-distortion control framework for GEMM for the broad class of zero-mean, independent identically distributed, input sources. Our approach converts matrix multiplication in programmable processors into a computation channel: when increasing the processing throughput, the output noise (error) increases due to (i) coarser quantization and (ii) computational errors caused by exceeding the machine-precision limitations. We show that, under certain distortion in the GEMM computation, the proposed framework can significantly surpass 100% of the peak performance of a given processor. The practical benefits of our proposal are shown in a face recognition system and a multi-layer perceptron system trained for metadata learning from a large music feature database.Comment: IEEE Transactions on Signal Processing (vol. 60, 2012

Integrating Vehicle Slip and Yaw in Overarching Multi-Tiered Automated Vehicle Steering Control to Balance Path Following Accuracy, Gracefulness, and Safety

Balancing path following accuracy and error convergence with graceful motion in steering control is challenging due to the competing nature of these requirements, especially across a range of operating speeds and conditions. This paper demonstrates that an integrated multi-tiered steering controller considering the impact of slip on kinematic control, dynamic control, and steering actuator rate commands achieves accurate and graceful path following. This work is founded on multi-tiered sideslip and yaw-based models, which allow derivation of controllers considering error due to sideslip and the mapping between steering commands and graceful lateral motion. Observer based sideslip estimates are combined with heading error in the kinematic controller to provide feedforward slip compensation. Path following error is compensated by a continuous Variable Structure Controller (VSC) using speed-based path manifolds to balance graceful motion and error convergence. Resulting yaw rate commands are used by a backstepping dynamic controller to generate steering rate commands. A High Gain Observer (HGO) estimates sideslip and yaw rate for output feedback control. Stability analysis of the output feedback controller is provided, and peaking is resolved. The work focuses on lateral control alone so that the steering controller can be combined with other speed controllers. Field results provide comparisons to related approaches demonstrating gracefulness and accuracy in different complex scenarios with varied weather conditions and perturbations

Analysis domain model for shared virtual environments

The field of shared virtual environments, which also encompasses online games and social 3D environments, has a system landscape consisting of multiple solutions that share great functional overlap. However, there is little system interoperability between the different solutions. A shared virtual environment has an associated problem domain that is highly complex raising difficult challenges to the development process, starting with the architectural design of the underlying system. This paper has two main contributions. The first contribution is a broad domain analysis of shared virtual environments, which enables developers to have a better understanding of the whole rather than the part(s). The second contribution is a reference domain model for discussing and describing solutions - the Analysis Domain Model

Mobile Information Systems 3 (2007) 107-132 107 IOS Press High performance publish/subscribe middleware for mobile wireless networks

Abstract. Decoupling, flexible, scalable and asynchronous nature of publish/subscribe paradigms makes them a good choice for mobile wireless networks. However, our research shows that current implementations of publish/subscribe systems as well as the traditional solutions for extending publish/subscribe systems to the mobile domain do not perform well in highly mobile and unreliable wireless settings. We present semi-durable subscriptions, a technique that we have developed to overcome the challenges and the performance concerns publish/subscribe systems face in mobile wireless settings. We discuss the architecture of semi-durable subscriptions and study in detail the effect of various mobility parameters on the performance of semi-durable subscriptions to demonstrate their efficacy in mobile wireless settings. We also discuss system parameters for semi-durable subscriptions and with the help of experimental results demonstrate how these parameters can be controlled to configure a system according to a set of desired characteristics

Creation of a Cloud-Native Application: Building and operating applications that utilize the benefits of the cloud computing distribution approach

Dissertation presented as the partial requirement for obtaining a Master's degree in Information Management, specialization in Information Systems and Technologies ManagementVMware is a world-renowned company in the field of cloud infrastructure and digital workspace technology which supports organizations in digital transformations. VMware accelerates digital transformation for evolving IT environments by empowering clients to adopt a software-defined strategy towards their business and information technology. Previously present in the private cloud segment, the company has recently focused on developing offers related to the public cloud. Comprehending how to devise cloud-compatible systems has become increasingly crucial in the present times. Cloud computing is rapidly evolving from a specialized technology favored by tech-savvy companies and startups to the cornerstone on which enterprise systems are constructed for future growth. To stay competitive in the current market, both big and small organizations are adopting cloud architectures and methodologies. As a member of the technical pre-sales team, the main goal of my internship was the design, development, and deployment of a cloud native application and therefore this will be the subject of my internship report. The application is intended to interface with an existing one and demonstrates in question the possible uses of VMware's virtualization infrastructure and automation offerings. Since its official release, the application has already been presented to various existing and prospective customers and at conferences. The purpose of this work is to provide a permanent record of my internship experience at VMware. Through this undertaking, I am able to retrospect on the professional facets of my internship experience and the competencies I gained during the journey. This work is a descriptive and theoretical reflection, methodologically oriented towards the development of a cloud-native application in the context of my internship in the system engineering team at VMware. The scientific content of the internship of the report focuses on the benefits - not limited to scalability and maintainability - to move from a monolithic architecture to microservices