K. K. Phang

University of Malaya | UM · Department of Computer System & Technology

Purpose When accessing the structured contents in XML form, information requests are formulated in the form of special query languages like NEXI, Xquery etc. However, it is not easy for end users to compose such information requests using these special queries due to their complexities. Hence, automated construction of such queries from common que...

The Compute Aggregate model used to model Map Reduce does not allow for dynamic node reordering once a job has started, assumes homogenous nodes and a balanced tree layout. We introduce heterogeneous nodes into the tree structure, thereby causing unbalanced trees. Finally, we present a new programming abstraction to allow for dynamic tree balancing...

Purpose – This paper aims to focus on automatic selection of two important structural concepts required in an XML query, namely, target and constraint concepts, when given a keywords query. Due to the diversities of concepts used in XML resources, it is not easy to select a correct concept when constructing an XML query. Design/methodology/approac...

Long-Term Evolution (LTE) was implemented to fulfill and satisfy users’ needs as well as their demands for an improvised, fast and efficient Quality of service (QoS). A minimal aggregate of waiting time in return would give users a better Quality of experience (QoE). Real-time service packet scheduling is an important process in allocating resource...

Looking at the amount of structured contents available on the web in recent years, we can be certain that the needs of structured retrieval systems are getting more prominent. In order to access the structured contents, information requests are formulated in the form of query languages supported by the structured retrieval systems. Nevertheless, in...

Current research and development of structured retrieval systems allow search communities to tap into structured resources over the web. These resources have advantages compared with the normal web resources as they have additional annotations that can be utilized when composing a search request. However, structured query languages used by these re...

IEEE 802.11 provides multiple wireless networking (WLAN) standards with each new standard attempting to improve overall performance whilst remaining backward compatible to older ones. The current practise of setting up WLANs is to use non-overlapping channels and high signal strengths to provide optimum performance for stations in the network. In t...

The use of grid technology and web services for resource sharing has received tremendous attention in recent years. The merging of these 2 technologies is able to provide additional multiple types of services and functionalities. However, the problem of scheduling services to meet quality of service (QoS) requirements remains challenging. This pape...

An important aspect of traffic engineering is the re-optimization of network resources. In this process, traffic over a congested path is rerouted to a new path to improve efficiency in network resource utilization. The aggregation nature of DiffServ MPLS networks often gives rise to long-lived flows within the network. A rerouting mechanism that s...

The availability of semantically rich structured resources makes the search of such resources on the web even more interesting, where the formation of a meaningful structured query is now possible for better retrieval. Incorporation of concepts like role, category, topic, class, attributes, etc. to indicate the search target and constraints in a st...

The demand for end-to-end Quality of Service (QoS) in Wireless Local Area Networks (WLANs) is becoming ever more important due to the trend towards converged communication networks. The recently accepted QoS mechanism in WLAN: the IEEE 802.11e has limitations in providing fairness to different types of traffic. We proposed Dynamic Weighted Fair Sch...

Recent years, the availability of public accessible structured resources like XML on the web has led to active developments of structural retrieval systems. With these systems, users will be able to query for information from structured resources on the web efficiently. When querying, it is obvious that usage of structural information in query incr...

The increase in proliferation of mobile devices and wireless technologies in recent years has opened up new challenges in mobile ad hoc networks (MANET). This growth has also led to an increase in demand of applications such as streaming video, multi-player interactive games and financial services such as real-time stock quotes. Such applications i...

To mimic the operations in fixed infrastructures and to solve the routing scalability problem in large Mobile Ad Hoc Networks (MANET), forming clusters of nodes has been proven to be a promising approach. However, when existing weighted clustering algorithms calculate each node's weight, they either consider only one metric or rely on some metrics...

With the emergence of new network applications and quality of service (QoS) requirements, current Internet technology that supports best-effort service is clearly insufficient. This paper undertakes a detailed study of dynamic quality of service routing in Differentiated Service (DiffServ) Multiprotocol Label Switching (MPLS) networks. A polynomial...

As web service has become the emerging paradigm, the area of web service research has received a lot of attention in recent years. Most of the web services are deployed by site administrators. As the number of request of web services increase tremendously, there is a need to replicate the services to multiple resources. Although manual deployment a...

In this paper, an intra-domain, multi-area Quality of Service (QoS) provisioning mechanism, namely the QoS-HBB architecture is proposed to alleviate the scalability problem in the intra-domain bandwidth broker design. By exploiting the inherent hierarchical nature of OSPF and the fact that an OSPF domain can be subdivided into multiple areas, QoS-H...

This paper proposes an optimistic concurrency control (CC) algorithm, called Sequential Order with Dynamic Adjustment (SODA), that guarantees timely and correct execution of concurrent transaction in Mobile P2P databases. In Mobile P2P, as every peer is fully autonomous, needs timely response and has inherent characteristics (mobility, low bandwidt...

Google entered China market as a late-comer in late-2005, with no local employees, an inadequate product line, and small market share. This talk will discuss Google China's efforts to build up a team, learn about local user needs, apply its global innovation ...

In a mobile ad hoc network (MANET), when a node fails during the RTS-CTS handshake process, the MAC protocol is able to identify whether the failure was caused by link failure or due to congestion by inspecting the recorded radio signal strengths. If the cause is due to actual link failure, then MAC abandons any further attempt to retry communicati...

The development of software has always been characterized by parameters that possess certain level of fuzziness. This requires that some degree of uncertainty be introduced in the models, in order to make the models realistic. Fuzzy logic fares well in this area. Many of the problems of the existing effort estimation models can be solved by incorpo...

The search that involves structured web resources like XML data, services is still lagging of its own method and relying on contemporary search systems. This paper presents a method that learns semantics from structured information of these resources. Instead of committing the semantic meaning of resources to strict and formal vocabularies like ont...

Congestion control mechanism such as random early detect (RED) allows more efficient usage of network resources. RED uses static thresholds (high and low) in combating congestion. However, as network becomes more dynamic with the introduction of multimedia and real time application, this ldquostaticrdquo approach becomes inefficient. This paper pro...

A campus-wide grid and cluster infrastructure using the Rocks clustering software is established. The infrastructure, namely Grid-Enabled Research Network and Info-structure of University of Malaya (GERANIUM), comprises five distinct clusters located at different faculties and institutes. In this paper, the GERANIUM topology and architecture are pr...

The primary issue with anycast routing protocol is the tradeoff between performance and reliability. An anycast routing protocol that can provide shorter end-to-end delay does not always has lower packet loss, and vice versa. This paper focuses on achieving short end-to-end delay and low packet loss, and proposes an enhancement to the anycast routi...

In the paper, a traffic engineering enhancement to the QoS-OSPF routing protocol is proposed and used as the path selection algorithm in a DiffServ-MPLS network. The proposed scheme, TE-QOSPF, exploits the use of non-shortest paths to improve load-balancing and avoid network congestion. Simulation results show that the algorithm outperforms the QoS...

The ATM Forum has released an ATM Security Specification that contains the requirements and specifications of security support services. The ATM Security Specification suggests placing all the security features in the user plane, control plane, management plane, ATM adaptation layer and ATM layer of ATM network architecture. Implementing security f...

Anycast is a network service provided in IPv6. A group of servers that provide same services will be assigned the same anycast address. A client wishing to contact the server will send the packets to this anycast address and the anycast-supported router will direct the packets to the nearest server. This paper analyses the performance of single-pat...

This paper describes a fuzzy usage parameter control (UPC) mechanism in DiffServ (DS) and Multiprotocol Label Switching (MPLS) networks based on fuzzy logics. Current research treats MPLS as the Internet’s solution to high performance network. In DS network, UPC is an important factor in ensuring the sources conforms to the negotiated service level...

Due to the unpredictable behavior of the traffic and various traffic characteristics, it has become a great challenge for ATM networks to effectively control traffic and congestion while at the same time provide the desired quality of service. In this paper, a fuzzy logic traffic controller is proposed to perform traffic and congestion control func...

The paper describes: fuzzy data and linguistic qualifiers; fuzzy data representation and retrieval; fuzzy database aspects; relational and object-oriented models; and the advantages of using the object-oriented database framework in a fuzzy database. A prototype fuzzy object-oriented database system (FOODS) has been implemented to demonstrate its f...

Provides a definition on electronic publishing, as well as the various components including the necessary infrastructure, the technology required, the production processes and the means of distribution. Some brief accounts of exemplary models of electronic publishing are given and discussed. The main issues and problems which may be encountered whe...

Describes i) necessity of fuzzy DataBase ii) techniques used in the storage and retrieval of fuzzy data in a DataBase or information retrieval system iii) DataBase framework for fuzzy DataBase and iv) the advantages of using object-oriented DataBase framework in fuzzy DataBase. A prototype of fuzzy object-oriented DataBase system, (FOODS), has been...

Describes the architecture of the fuzzy logic controller (FLC) and its advantages in various industrial applications. A prototype of cooperative neural fuzzy controller, CONEFCON, has been developed to demonstrate the feasibility of FLC.