Activity-Centric Computing Systems

• Activity-Centric Computing (ACC) addresses deep-rooted information management problems in traditional application centric computing by providing a unifying computational model for human goal-oriented ‘activity,’ cutting across system boundaries. • We provide a historical review of the motivation for and development of ACC systems, and highlight the need for broadening up this research topic to also include low-level system research and development. • ACC concepts and technology relate to many facets of computing; they are relevant for researchers working on new computing models and operating systems, as well as for application designers seeking to incorporate these technologies in domain-specific applications

Requirements for implementing real-time control functional modules on a hierarchical parallel pipelined system

Analysis of a robot control system leads to a broad range of processing requirements. One fundamental requirement of a robot control system is the necessity of a microcomputer system in order to provide sufficient processing capability.The use of multiple processors in a parallel architecture is beneficial for a number of reasons, including better cost performance, modular growth, increased reliability through replication, and flexibility for testing alternate control strategies via different partitioning. A survey of the progression from low level control synchronizing primitives to higher level communication tools is presented. The system communication and control mechanisms of existing robot control systems are compared to the hierarchical control model. The impact of this design methodology on the current robot control systems is explored

Telescience Testbed Pilot Program

The Telescience Testbed Pilot Program is developing initial recommendations for requirements and design approaches for the information systems of the Space Station era. During this quarter, drafting of the final reports of the various participants was initiated. Several drafts are included in this report as the University technical reports

AO-40 RUDAK Experiment Controller

The AMSAT AO-40 satellite now on orbit contains several experiments controlled through a module called RUDAK. It is presently in an extended GTO orbit with an apogee of about 58,000 km. The primary mission of this satellite is to provide a platform for multiple communications transponders. The RUDAK module provides digital communications functions as well as serving as the controller for most of the exp eriments onboard. This paper focuses on RUDAK and the associated experiments. The RUDAK module is capable of providing a wide variety of digital communications functions and includes dual processors, mass memory and a suite of hardware and DSP modems. It has connectivity to the transponders, main housekeeping computer and to the experiments onboard. To this point in the mission it has been exercised primarily as an experiment controller. The experiments operated through RUDAK include: - two cameras - an equipment set for receiving and measuring GPS signals - a radiation measurement experiment - an experiment to measure HF signal characteristics - two CAN bus temperatures measurement nodes. Interesting and in some cases unique results have been obtained from the GPS, radiation monitor, cameras and temperature measurement nodes. The associated principal investigators are reporting details of those results independently. This paper describes the RUDAK experiment control module, how it was designed and optimized for this mission, how it controls and interacts with the experiments, the software issues associated with this function, operational issues and successful experiment interaction achieved so far. A summary of the results from some of the experiments is included, with emphasis on the unique data, but the focus is on the design and operation of RUDAK as an experiment controller. Information on those design and operational features that have worked well as well those that have provided challenges are included

Towards a Video Consumer Leaning Spectrum: A Medium-Centric Approach

Purpose: As TV and digital video converge, there is a need to compare advertising effectiveness, advertising receptivity, and video consumption drivers in this new context. Considering the emerging viewing practices and underlying theories, this study examines the feasibility of the traditional notion of differentiating between lean-back (LB) and lean-forward (LF) media, and proposes a revised approach of addressing video consumption processes and associated advertising effectiveness implications. Methodology: An extensive, systematic literature review examines a total of 715 sources regarding current lean-back/lean-forward media research and alternative approaches as by (1) basic terminologies, (2) limitations of lean-back/lean-forward situations, (3) advertising effectiveness implications, (4) video-specific approaches. Findings/Contribution: Key differences between lean-back and lean-forward video consumption are presented. A conceptual integration of video ad receptivity/effectiveness drivers is proposed to guide future media and marketing research and practice. Video consumption today is no longer lean-back or lean-forward, but a “leaning spectrum” with two dimensions: leaning direction and leaning degree. Designing video content today requires focusing on consumption drivers and platform synergies for owning the “leaning spectrum”

Analyzing the costs/tradeoffs involved between layer 2, layer 3, layer 4 and layer 5 switching

The switching function was primarily entrusted to Layer 2 of the OSI model, i.e. the Data Link Layer. A Layer 2 switch performs forwarding decisions by analyzing the MAC (Media Access Control) address of the destination segment in the frame. The Layer 2 switch checks for the destination address and transmits the packet to the appropriate segment if the address is present in its table of known destinations. If the entry for that address is not present, the switch then forwards the packet to all segments except the one on which it came from. This is known as flooding. When it gets a reply from the destination segment, it learns the location of the new address and adds it to its table of known destinations. As number of users are increasing on the network, the speed and the bandwidth of the network is being stretched to its limits. Earlier, switching was primarily entrusted to Layer 2 (Data Link Layer) of the OSI model, but now there are switches that operate at Layer 3 (Network Layer), Layer 4 (Transport Layer) and Layer 5 (Session Layer) of the OSI model. Going from one layer to the other layer does involve some costs/tradeoffs. My thesis explores the costs and tradeoffs involved with switching based on layers 2, 3, 4 and 5 of the OSI reference model