Tong-Ying Juang

Crash recovery with little overhead

Recovering from processor failures in distributed systems is an important problem in the design and development of reliable systems. Two solutions to this problem which involve very little overhead are presented. Without appending any information to the messages of the application program, it is shown that it is possible to recover from failures using O( mod V mod mod E mod ) messages where mod V mod is the number of processors and mod E mod is the number of communication links in the system. The second algorithm can be used to recover from processor failures without forcing nonfaulty processors to roll back under certain conditions.<<ETX>>

A Low Propagation Delay Multi-Path Routing Protocol for Underwater Sensor Networks

The large-scale mobile Underwater Wireless Sensor Network (UWSN) is a useful networking paradigm to explore underwater environments. The characteristics of mobile UWSNs, such as low communication bandwidth, large propagation delay, and floating node mobility are significantly different from wireless sensor networks. In this paper, we propose a new efficient routing protocol, called multi-path routing (MPR) protocol, for UWSNs to improve the transmission delay. Multi-path is utilized during the path construction from the source node to the destination node, which is composed of a series of multi-subpaths. Each multi-subpath is a sub-path from a sending node to its two-hop neighboring node, called receiving node, by one more relay nodes, where these relay nodes simultaneously are neighboring nodes of sending and receiving nodes. Due to the different propagation delay of UWSN, the packet arrival time along the different sub-path is different; thus it may avoid the data collision in the receiving node when receiving different packets from different relay nodes. It surely sends the different packet along different sub-path to significantly improve delay time and packet delivery ratio. Finally, simulation results illustrate the performance achievements of the MPR protocol in improving delay time, packet delivery ratio, throughput and reducing overhead ratio.

Congestion-free, dilation-2 embedding of complete binary Trees into star graphs

Trees are a common structure to represent the intertask communication pattern of a parallel algorithm. In this paper, we consider the embedding of a complete binary tree in a star graph with the objective of minimizing congestion and dilation. We develop two embeddings: (i) a congestion-free, dilation-2, load-1 embedding of a level-p binary tree, and (ii) a congestion-free, dilation-2, load-2k embedding of a level-(p + k) binary tree, into an n-dimensional star graph, where and k is any positive integer. The first result offers a tree of size comparable or superior to existing results, but with less congestion and dilation. The second result provides more flexibility in the embeddable tree sizes compared to existing results.

Fault Estimation and Fault Map Construction on Cluster-based Wireless Sensor Network

Most applications of wireless sensor networks (WSNs) the sensors are deployed on unfavorable environment such as chemical reactor or battlefield that with high temperature, noise, and interference, could probably incur sensor nodes sense, compute, or communicate improperly. Those also raise error responds to the data collectors. In this paper, a fault estimation model is proposed and can be used to construct the fault map which can be used in WSNs widely, especially in hostile environments. Sensor nodes are transmitting environmental data when it detected with some extra sensed data, such as outward temperature and noise. The fault probability can be estimated and recognized with this extra information using Bayesian belief network (BBN). In this paper, we develop a fault-estimation algorithm is based on the cluster-based framework and show how this model works to find out the probably faulty nodes. Then we simulate and construct the fault map of WSNs

Toward a NFC Phone-Driven Context Awareness Smart Environment

Near Field Communication (NFC) is a two-way communication technology based on RFID. NFC-equipped phone (NFC phone) that embed the NFC technology into cellular phone earns increasingly attention in business, such as payment and ticketing. This paper presents a novel architecture for NFC phone driven context-aware smart spaces. Based on the architecture, users can take a NFC phone that carry predefined personal desire to control devices, such as home appliances. The appliances can be controlled and driven by the request sent from a NFC phone without considering the context of the environment by using predefined ontology and rule-based reasoning. We also implemented a prototype to demonstrate the feasibility of the architecture and evaluate the performance to show the efficiency.

A Cross-Layer Partner-Assisted Handoff Scheme for Hierarchical Mobile IPv6 in IEEE 802.16e Systems

In this paper, a new approach is proposed to reduce handoff operation in IEEE 802.16e network. Traditional mobile approaches, such as mobile IPv6 (MIPv6) and hierarchical MIPv6 (HMIPv6), can support smoothly handoff. These approach, ,unfortunately, suffer large handoff delay and packet lost in macro mobility for mobile users. With the aid of the partner node, DAD operation can be pre-executed by the partner node before the mobile node initialize the handoff request, we propose a cross-layer partner based fast handoff mechanism based on HMIPv6 in IEEE 802.16e network, called as P_HMIPv6 protocol. The P_HMIPv6 protocol is a cross-layer, layer 2 and layer 3, approach. The partner station (PS), which is a new component with relay ability and adopted by our protocol, is a static mobile station (MS). With the aid of the PSs, care-of address (CoA) can be pre-acquired and DAD operation can be pre-executed by the PS before the MS initials the layer 2 handoff. The simulation results show that P_HMIPv6 protocol actually achieves the performance improvements in the handoff delay time and the packet loss.

Multi-node broadcasting in an arrangement graph using multiple spanning trees

The arrangement graph A/sub n,k/ is not only a generalization of the star graph (n-k=1), but is also more flexible. Designing an efficient routing algorithm on a regular interconnection network is a fundamental issue for parallel processing techniques. We elucidate the multi-node broadcasting problem in an all-port communication model on the arrangement graph. Our routing strategy is proposed by construction of 2(n-k) spanning trees, where the height of each spanning tree is 2k-1. We also extend the routing strategy to a one-to-all broadcasting algorithm. Using 2(n-k) spanning trees allows us to present efficient (one/multi)- node broadcasting algorithms in the arrangement graph. The arrangement graph is assumed to use one-port and all-port models and packet-switching (or store-and forward) technique. Moreover we show that our (one/multi)-node broadcasting algorithms outperform previous results in the literature. This is justified by our performance analysis.

An Architecture for Video Surveillance Service Based on P2P and Cloud Computing

Video Surveillance Services is increasingly becoming important part in daily live. For traditional distributed Video Surveillance Services, each video catcher will store its streaming data to server. It will create a great volume of data daily. The approach obviously incurs some problems in keeping daily data into the data center (DC), such as limited bandwidth to DC, limited space of DC, overloading to DC, reliability, scalability, and so on. In this paper, we propose a novel architecture based on well-developed peer to peer technology and emerging cloud computing for solving the issues. The architecture exploits inherent characteristics of P2P and Cloud computing to provide an economic, scalable, reliable and efficient approach to store video data. We present the architecture, components, its operation flow, and depict the implementation issue in this paper. We believe that the architecture can improve significantly issues.

Integrating intelligent agent and ontology for services discovery on cloud environment

With the advance of cloud computing, cloud service providers (CSP) provide increasingly diversified services to users. To utilize general search engine, such as Google, is not an effective and efficient if the services are similar but with different attributes. Therefore, an intelligent service discovery platform is necessary for seeking suitable services accurately and quickly. In the paper1, we propose a framework that integrates intelligent agent and ontology for service discovery in cloud environment. The framework contains some agents and mainly assists users to discovering suitable service according to user demand. User can submit his flat-text based request for discovering required service. We implement a cloud service discovery environment to demonstrate the concept and its application. We also utilize the Recall and Precision to evaluate the accuracy of the system.

An Euler-path-based multicasting model for wormhole-routed networks: its applications to damaged 2D Tori and meshes

We develop a new multicasting model for wormhole-routed networks based on the concept of Euler path in graph theory. The model can support multiple multicasts freely from deadlock and can be applied to any network which is Eulerian or is Eulerian after some links being removed. We demonstrate the power of this model by showing its fault-tolerant capability in supporting multicasting in a damaged 2-D torus/meshes with regular fault patterns (such as a single node, block, L-shape, +-shape, U-shape, and H-shape). In this regard, it is the first known multicasting algorithm in the literature with such strong fault-tolerant capability.