Wireless sensor network supports reliable monitoring of the given network based upon the data transmitted from the sensors. However, the feasibility can be maintained only when the delivered data are fairly reliable without any damage. Since data error is not an uncommon event in wireless sensor networks, the validity of the decision making strongly depends upon the stableness of the data analysis technique with partially damaged data. In this paper, we introduce a data mining mechanism and apply it to the processing of data which are missing or inconsistent.

Recently, one of the great threats of spam related activities is that of phishing, which directs users to enter credential information at a malicious website whose visual look is almost identical to the trustworthy one. In this paper, we propose and develop a framework for a web-based, automated application to identify potential phishing websites. The advantage of the proposed application comes from comprehensively inspecting the URL format, validation of the URL content, and fingerprint of the requested website.

As the technology surrounding smart phone devices has changed over the past few years, we now find a device containing a collection of sensors. Indeed, one can say that the development of smart phones has been one of the most important advances in science and technology. We will show an additional usage for the smart phone: utilizing it for a generic, hardware, gaming controller. We will show how a motion recognition mechanism can be used for determining rate of change and position of the phone as it moves in 3D-space using the embedded 3-axes accelerometer sensor. Upon sensing a user's motions with the smart phone, the corresponding accelerometer values are transmitted to the gaming console through the Wi-Fi communication. Motion recognition is then performed at the gaming console using a pattern matching mechanism. The proposed mechanism is applied to the game of tennis to recognize three primary ground stroke motions: the forehand stroke, backhand stroke, and service. With individual calibration for these three motions, we show how accurately the system can recognize the motions, and derive ball-hit likelihood. These types of results, when fully realized, can provide a much richer and simpler experience for the user.

Medical sensor devices, such as ECG, handle life-critical information, which have to be transmitted to remote monitoring servers in a timely manner. We propose a new approach to improve QoS of ECG data transmission when these devices are deployed in home or healthcare facility supported by EDCA-based WLANs. First, we analyze real-time data from wireless ECG devices to investigate their QoS requirements, and convert them to a real-time model with (m, k)'-firm deadlines. Second, we propose a new admission control mechanism to protect real-time ECG data transmission from other traffic initiating from non-medical applications. Finally, we propose our solution to cope with potential adverse effects from co-existence with the legacy DCF-based wireless stations.

We propose a primary path switching scheme to provide a seamless handover for dual-homed mobile terminals. This scheme is suggested as an enhancement to the mSCTP protocol. With our scheme, a mobile terminal performs primary path switching before it becomes unavailable due to its primary path drop. The improvement of the scheme comes from considering the temporal velocity of the mobile terminal with relative RTT variances of all available paths when it performs a handover process in the overlapped area between two different networks. Our simulation results show the proposed scheme provides a better overall performance than other schemes and the anticipatory switching is more important for faster moving terminals.

In this article, a video multicast protocol for multi-homed mobile terminals is proposed as an alternative stream control transmission protocol (SCTP) for partially reliable multicast services. It works with overlay peer-to-peer video multicast facility in the application layer. For a multi-homed mobile terminal, an error burst may occur when a handover is in process in the primary path switching procedure. The key issue concerned in this protocol is the ability to predict packet loss and to retransmit the lost packets as soon as a mobile terminal completes its primary path switching procedure. This property controls the delay sensitivity of transmissions. Conversely, the protocol can tolerate partial loss in video transmission as long as the loss is limited to a relatively short error burst. In addition, it reduces the message overhead significantly and provides a scalable communication mechanism for multicast applications. The performance improvement of the proposed protocol comes from 1) the estimation of temporal velocity of mobile terminals with lost packet prediction in a long error burst, and 2) the requirement for each mobile terminal to indicate which packets can be safely discarded from its agent.

Tree-based reliable multicast protocols provide scalability by distributing error-recovery tasks among several repair nodes. These repair nodes keep in their buffers all packets that are likely to be requested by any of its receiver nodes. We address the issue of deciding how long these packets should be retained and present a buffer management scheme taking into account the fact that most packet losses happen during short error bursts. Under our scheme, receiver nodes do not normally acknowledge correctly received packets and repair nodes routinely discard packets after a reasonable time interval. Whenever a receiver node detects a transmission error, its send a negative acknowledgement to its repair node and start acknowledging up to k correctly received packets. Whenever a repair node receives a retransmission request, it stops discarding packets that have not been properly acknowledged until it has received k consecutive acknowledgements from each node that had requested a packet retransmission.

Tree-based reliable multicast protocols provide scalability by distributing error-recovery tasks among several repair nodes. These repair nodes integrate the status information of several receiver nodes and perform local error recovery for these nodes using the data stored in their buffers. We propose a buffer management scheme that uses both positive and negative acknowledgments to manage these buffers in an efficient manner. Under our scheme, receiver nodes send negative acknowledgments to repair nodes to request packet retransmissions. At infrequent intervals, they also send positive acknowledgements to indicate which packets can be safely discarded from the buffer of their repair node. Our scheme reduces delay in error recovery, because the packets requested from the repair nodes are always available in their buffers. It achieves this goal without increasing the server workload because (a) each receiver node only sends infrequent positive acknowledgments and (b) their sending times are randomized among all the receiver nodes. We also show how our scheme can be extended to provide full flow control and eliminate buffer overflows.

Tree-based reliable multicast protocols provide scalability by distributing error-recovery tasks among several repair nodes. These repair nodes integrate the status information of their receiver nodes and perform local error recovery for these nodes using the data stored in their buffers. In order to provide scalability and reliability, these buffers should be managed in an efficient manner. We propose a heuristic buffer management scheme that uses both positive and negative acknowledgments to achieve this goal. Under our scheme, receiver nodes send negative acknowledgments to their repair nodes to request packet retransmissions while some representative nodes send positive acknowledgments to indicate which packets can be discarded from the repair node's buffer. Our scheme provides scalability, because it significantly reduces the number of feedbacks sent by the receiver nodes, in addition, it provides fast recovery of transmission errors, since the packets requested from the receiver nodes are almost always available in their buffers.