Yu-Chung Wang

An open real-time environment for parallel and distributed systems

Most computer-based systems have hard real-time constraints. Schedulers in complex systems must be designed to manage a set of applications developed and deployed independently. We study an open real-time environment architecture for distributed systems where real-time applications may run concurrently with non-real-time applications. The architecture uses a two-level scheduling scheme. Each application is assigned a sporadic server to schedule the processes in the application. All sporadic servers are then scheduled by a system-wide fixed priority scheduler. Using the proposed open environment architecture, all hard real-time applications are guaranteed to have their reserved CPU utilization in order to meet all their deadlines. The guarantee is independent of the behaviors of all other applications in the same system. We present the schedulability analysis methods on systems with or without shared memory.

Building Smart M2M Applications Using the WuKong Profile Framework

This paper presents a project on building intelligent middleware on wireless sensor devices for machine-to-machine systems (M2M). Most current M2M and IoT applications are built for fixed sensor platforms with a specific wireless network support. Such software supports a unique set of sensors, and results in applications that are fragile and cannot be ported to other platforms. Our research is to develop intelligent middleware for deploying flexible and evolvable applications. We implement the application deployment capability where an M2M application does not need to be constrained on what and how sensors are deployed. Our intelligent M2M middleware can automatically perform sensor identification, node configuration, software upgrade, and system re-configuration.

EMWF for Flexible Automation and Assistive Devices

This paper describes an embedded workflow framework (EMWF) that enables flexible personal and home automation and assistive devices and service and social robots (collectively referred to as SISARL) to be built on workflow architecture The process definition language supported by EMWF is called SISARL-XPDL. It consists of a subset of the WfMC standard XML Process Definition Language (XPDL) 2.0, together with elements that implement common mechanisms for robot behavior coordination. SISARL-XPDL definitions of workflows are first translated into standard XPDL and execution directives and then are parsed either directly into binary workflow scripts for execution or into intermediate scripts in C. EMWF provides workflow engines for Linux and Windows CE platforms. The engines are written in C in order to keep their memory footprint and runtime overhead small. Performance data show that the overheads introduced by the engine and workflow data are tolerable for most SISARL devices.

Trustworthy emergency information brokerage service (TIBS)

Availability and timeliness of relevant information is of paramount importance during disaster response. Structural and situational information should be made available lavishly to decision makers, field workers, victims, even the general public provided that it would be possible to track down potential abuses. The trustworthy emergency information brokerage service (TIBS) described in this paper was developed based on such a conviction. This pervasive information flow control system offers information desensitization, flow traceability and use accountability services in two separate phases of disaster management: (1) in the preparatory phase, a prospective P-TIBS subsystem will provide information filtering and fusion tools that can help resource owners to desensitize organizational/structural information and store them in a virtual repository deployed pervasively on many points of service (POS); (2) during the disaster responsive phase, a retrospective R-TIBS subsystem will lease the desensitized information and offer information flow traceability as well as use accountability services according to pre-specified information release and accountability policies. This accountability approach will be more scalable and responsive than the “breakthe-glass” access control overriding mechanism available in many hospital information systems as it alleviates the need to authenticate individual users and authorize their emergency information access. This paper provides an overview of the TIBS system architecture and the enabling technology it employs.

File Layout Design of VBR Video on Zoned-Disks

As the advances of the technologies of networking, compression techniques and storage devices, video media are widely utilized in many applications, such as entertainment and education. The video contents are usually stored as a sequence of frames that every frame represents a single image snapshot. When viewed by human beings, the video playing timing is critical for viewing effect. I.e. each frame has to be delivered to and played by the viewer machine within a time window in order not to produce observable jitters. Another reason for the timing constraint is to synchronize video media with other media, such as voice and text, of a multimedia application. In order to sustain the system-wide quality-of-service(QoS) a storage system has to provide performance guarantees as it plays a major role in supporting a real-time video media.

Design and implementation of ASIS multimedia digital library

In this paper, we present our design and implementation of ASIS multimedia digital library. Besides bibliographic information, our service includes an archive of digital audio and video streams, CD titles, and WWW contents. This system not only aims at end customer supports, e.g., searching, streaming, and browsing operations, but it also facilitates admission control, content production, distribution processes, and license control, etc. We address several design issues in designing a multimedia digital library, e.g., the need for accounting support and system management, for integrating third party system components and varied kind of multimedia, and for a computer aided tool to automatically process the backend production. Our solutions to these problems are presented.