With the advent of new technologies such as multimedia and high-speed network, there is increasing demand for computer systems with stringent timing constraints. New application domains also demonstrate that the timely management of resources and information is of paramount importance. Among the many types of applications for which time-constrained and predictable response is required, the most familiar are multimedia applications, electronic games, defense systems, and electronic trading systems. These time-critical applications depend on careful system design and timely resource allocation to deliver the required performance. Although these time-critical applications are used so frequently in our daily life, there is, in general, little support in building such systems. Many commercial operating systems such as Microsoft Windows and Linux still do not possess enough capability to allocate resources in a timely fashion.

My research interests include real-time databases, real-time process scheduling, real-time operating systems, embedded systems, and system security. The current research directions can be classified as follows:

• Quality-of-Service (QoS) Guarantee

The goal is to deliver QoS guarantee to application systems, processes, or threads in various platforms. Our work on real-time systems techniques can be backtracked back to late 1980 since my graduate study. We currently focus ourselves on the hard real-time support at the thread level and on the soft real-time support at the user-application level. Real-time CPU scheduling and resource allocation is our expertise. We do a lot of implementation work on real-time Linux recently. Our current effort is in the following directions:

1. Hard QoS Guarantee under RTAI-Linux - a Real-Time Linux.

2. Soft QoS Guarantee under RTAI-Linux - a Real-Time Linux.

3. Bus-Bandwidth QoS Guarantee

4. Real-Time Process Scheduling Techniques

5. RAID Systems

• Embedded Systems

Our research on embedded systems currently focuses on flash-memory file systems and micro real-time kernels. We are interested in low power consumption and high-performance flash systems, although they apparently have conflicting goals. Implementations on Linux are also involved. We also have our implementation of a micro real-time kernel which could be easily ported to many platforms, such as 8051, 80x86, or ARM. The current effort is in the following directions:

1. Micro Real-Time Kernel with Energy-Efficiency Considerations

2. Power Consumption versus Performance over Flash-Memory File Systems of Portable Devices

3. High-Performance Flash-Memory File Systems With/Without Real-Time Support

4. Advanced System Designs for Flash-Memory File Systems

5. Energy-Efficient Scheduling

• Information Systems

In my opinions, research on information system covers work on database systems. We start our work on real-time database systems (which are database systems with response time requirements) since late 1980. Our research on information systems spread over from the bottom, such as disk problems, to the system level, such as concurrency control and recovery, and up to the surface, such as indexing and data organization. Our current research directions are more on large-scale information systems and mobile applications:

1. High-Performance XML Storage

2. High-Performance Federated Information Systems with Fail-Soft Support

3. Medical Information Systems

4. Location Management for Mobile Applications

• System Security

Security has become a critical issue either for proper service delivery or information protection. We believe that research on system security should base on industrial standards and practical needs. Our work is not on virus technology. Instead, we exploit the security issues of operating systems and communication technology. Tradeoffs between performance and security would be our focus:

1. Security-Enhanced Operating Systems for Gateways

2. Security-Enhanced Communication

In the past decade, we have done a lot of work in the following directions:

• real-time databases
  • concurrency control of data access
  • failure recovery
  • issues in mobile and distributed environments
  • traffic and navigation information systems
• real-time operating systems
  • processor reservation or GPS-based scheduling
  • adaptive systems
  • schedulability analysis
  • real-time process scheduling
  • CPU reservation tools
  • monitor softwares
• embedded systems
  • embedded real-time operating systems
  • embedded devices
  • industrial control
• system security
  • security-enhanced operating systems
  • gateway operating systems
  • intrusion detection

• Real-Time Process Scheduling
• Real-Time Linux
• Embedded Linux
• Utilities for Real-Time Support on Commercial Operating Systems
• Real-Time RAID
• Security-Enhanced Operating Systems for Gateways
• Security-Enhanced Communication

• Real-Time Databases - Concurrency Control & Recovery
• Data Clients/Servers and Management
• E-Commerce

• General-Purpose Radar Systems
• Embedded Systems
• CDTI Collision Avoidance Systems

Special thanks for the support from the ROC National Science Council, the ROC Ministry of Economic Affairs, the Chung-Shan Institute of Science and Technology, the Institute for Information Industry, the Pou Chen Corp, and the RedSonic Corp.