Ken Wong - Academia.edu (original) (raw)

Papers by Ken Wong

Biotechnology and Bioengineering, 1988

Steam explosion after sulphur dioxide impregnation of wood chips is an effective method for impro... more Steam explosion after sulphur dioxide impregnation of wood chips is an effective method for improving the enzymatic digestibility of cellulose in the softwood Pinus radiata. Digestibility of pretreated fiber was progressively increased by altering the conditions of steam explosion. With increasing digestibility, there was an observed increase in fiber porosity as measured by the solute exclusion technique. Accessible pore volume and accessible surface area to a 5-nm dextran probe positively correlated with both 2- and 24-h digestion yields from pretreated fiber. The increase in accessibility was probably the result of hemicellulose extraction and lignin redistribution. A subsequent loss in accessibility, brought about by structural collapse or further lignin redistribution, resulted in a corresponding loss in digestibility. It appears that steam explosion increases cellulose digestibility in P. radiata by increasing fiber porosity.

University of California, Riverside University of California, Riverside University of California,... more University of California, Riverside University of California, Riverside University of California, Riverside stilley@cs.ucr.edu john.gerdes@ucr.edu thamilton@cs.ucr.edu ... Department of Computer Science Department of Computer Science Department of Computing Science

Over the last decade, programmable Network Processors (NPs) have become widely used in Internet r... more Over the last decade, programmable Network Processors (NPs) have become widely used in Internet routers and other network components. NPs enable rapid development of complex packet processing functions as well as rapid response to changing requirements. In the network research community, the use of NPs has been limited by the challenges associated with learning to program these devices and with using them for substantial research projects. This paper reports on an extension to the Open Network Laboratory testbed that seeks to reduce these "barriers to entry" by providing a complete and highly configurable NP-based router that users can access remotely and use for network experiments. The base router includes support for IP route lookup and general packet filtering, as well as a flexible queueing subsystem and extensive support for performance monitoring. In addition, it provides a plugin environment that can be used to extend the router's functionality, enabling users to carry out significant network experiments with a relatively modest investment of time and effort. This paper describes our NP router and explains how it can be used. We provide several examples of network experiments that have been implemented using the plugin environment, and provide some baseline performance data to characterize the overall system performance. We also report that these routers have already been used for ten non-trivial projects in an advanced architecture course where most of the students had no prior experience using NPs.

The Open Network Laboratory (ONL) is a remotely accessible network testbed of high performance ro... more The Open Network Laboratory (ONL) is a remotely accessible network testbed of high performance routers which has been designed with an eye towards ease of use for users from the naïve to the expert. The system is built around a set of high-performance routers that are extendible and easily configurable through the Remote Laboratory Interface (RLI), an intuitive graphical interface. The RLI also makes it easy to configure packet filters in the routers, assign flows or flow aggregates to separate queues with configurable QoS and attach hardware monitoring points to real-time charts. The RLI's real-time charts and user data facility make it easy to directly view the effects of traffic as it moves through a router, allowing the user to gain better insight into system behavior and create compelling demonstrations. Each port of the router is equipped with an embedded processor that supports software plugins which allow users to extend the system's functionality. This paper describes the ONL and how it can be used in networking education.

The Open Network Laboratory (ONL) is an Internet-accessible virtual laboratory facility that can ... more The Open Network Laboratory (ONL) is an Internet-accessible virtual laboratory facility that can deliver a high quality laboratory experience in advanced networking 7]. Our experience with ONL indicates that it has potential to improve student understanding of fundamental networking concepts and increase enthusiasm for experimentation with complex technology. Furthermore, these benefits can be delivered with less effort from the instructor than using a traditional approach of socket programming and ns-2 simulation exercises. The system is built around a set of high-performance, extendible routers which connect personal computers acting as end systems. Users configure their virtual network through the Remote Laboratory Interface (RLI), an intuitive graphical interface. The RLI's realtime charts and user data facility make it easy to directly view the effect of system parameters on traffic behavior. These features can enhance learning by providing users with multiple representations of network phenomena. We describe how the ONL facilities have improved our ability to meet instructional objectives and discuss some approaches to improving the laboratory experience.

This paper presents and evaluates distributed queueing algorithms for regulating the flow of traf... more This paper presents and evaluates distributed queueing algorithms for regulating the flow of traffic through large, high performance routers. Distributed queueing has a similar objective to crossbar-scheduling mechanisms used in routers with relatively small port counts, and shares some common high level characteristics. However, the need to minimize communication overhead rules out the iterative methods that are typically used for crossbar scheduling, while the ability to sub-divide the available bandwidth among different ports provides a degree of freedom that is absent in the crossbar scheduling context, where inputs must be matched to outputs.

This paper describes the design, implementation and performance of an open, high performance, dyn... more This paper describes the design, implementation and performance of an open, high performance, dynamically extensible router under development at Washington University in St. Louis. This router supports the dynamic installation of software and hardware plugins in the data path of application data flows. It provides an experimental platform for research on programmable networks, protocols, router software and hardware design, network management, quality of service and advanced applications. It is designed to be flexible without sacrificing performance. It supports gigabit links and uses a scalable architecture suitable for supporting hundreds or even thousands of links. The system's flexibility makes it an ideal platform for experimental research on dynamically extensible networks that implement higher level functions in direct support of individual application sessions.

Critical Reviews in Biotechnology, 1992

Page 1. Critical Reviews in Biotechnology. 12(5/6):4 13-435 (1 992) Trichoderma X y I a nases , T... more Page 1. Critical Reviews in Biotechnology. 12(5/6):4 13-435 (1 992) Trichoderma X y I a nases , T h ei r Pro pert ies and Application* Ken K. Y. Wong and John N. Saddler Chair of Forest Products Biotechnology, Faculty of Forestry ...

Bio/technology, 1994

Nature Biotechnology journal featuring biotechnology articles and science research papers of comm... more Nature Biotechnology journal featuring biotechnology articles and science research papers of commercial interest in pharmaceutical, medical, and environmental sciences.

Applied Biochemistry and Biotechnology, 1994

Adsorption of cellulases to cellulose is a critical step in the hydrolysis of cellulosic substrat... more Adsorption of cellulases to cellulose is a critical step in the hydrolysis of cellulosic substrates. However, the importance of adsorption in determining the hydrolysis rate is unclear. The accessibility to cellulases and specific hydrolysis rates were measured for various substrates. No correlation was found between the amount of enzyme adsorbed and the initial hydrolysis rate for different substrates. Specific hydrolysis rates were found to differ among substrates. Furthermore, both accessibility to cellulases and the specific hydrolysis rate of substrates were found to be changed by chemical and physical pretreatment of the substrate.

Holzforschung, 1997

Summary Model pulps, made by depositing lignin and/or xylan on cellulose fibers under alkaline co... more Summary Model pulps, made by depositing lignin and/or xylan on cellulose fibers under alkaline conditions, were subjected to a xylanase-chelation-peroxide bleaching sequence. On average, 14%(0.7 g) of the added xylan had been redeposited on 20g cellulose. ...

Journal of Biotechnology, 1996

Three commercial enzymes were used to evaluate the use of xylanase treatment for enhancing the pe... more Three commercial enzymes were used to evaluate the use of xylanase treatment for enhancing the peroxide bleaching of three oxygen delignified kraft pulps derived from the softwoods red cedar, Douglas fir, and western hemlock. Two bleaching sequences were examined, where the enzyme stage was placed before or between the two peroxide stages. The brightness gain achieved was dependent on the enzyme preparation, the origin of the pulp and the position of the enzyme stage in the bleaching sequence. In general, xylanase was found to enhance the pulp brightness achieved with two peroxide stages by l-1.5% ISO. It could directly brighten oxygen delignified pulps before and after the first peroxide stage. Direct brightening of the oxygen delignified pulps, before peroxide bleaching, appeared to be correlated with the amount of UV-absorbing material solubilized during the enzyme stage.