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Accurate estimation of the motion and shape of a moving object is a challenging task due to great variety of noises present from sources such as electronic components and the influence of the external environment, etc. To alleviate the noise, the filtering/estimation approach can be used to reduce it in streaming video to obtain better estimation accuracy in feature points on the moving objects. To deal with the filtering problem in the appropriate nonlinear system, the extended Kalman filter (EKF), which neglects higher-order derivatives in the linearization process, has been very popular. The unscented Kalman filter (UKF), which uses a deterministic sampling approach to capture the mean and covariance estimates with a minimal set of sample points, is able to achieve at least the second order accuracy without Jacobians’ computation involved. In this paper, the UKF is applied to the rigid body motion and shape dynamics to estimate feature points on moving objects. The performance evaluation is carried out through the numerical study. The results show that UKF demonstrates substantial improvement in accuracy estimation for implementing the estimation of motion and planar surface parameters of a single camera.

Vertical handoff is the switching process between heterogeneous wireless networks. Discovering the reachable wireless networks is the first step for vertical handoff. After discovering the reachable candidate networks, the mobile terminal decides whether to perform handoff or not. We present an adaptive scheme for vertical handoff in wireless overlay networks. Our system discovery method effectively discovers the candidate networks for the mobile terminal. Moreover, we propose two adaptive evaluation methods for the mobile terminal to determine the handoff time that relies on the candidates' resources and the running applications. The simulation results show that the proposed system discovery method can balance the power consumption and the system discovery time. Furthermore, the proposed handoff decision method can decide the appropriate time to perform handoff.

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In multihop MANETs, nodes have to cooperate to forward each other's packets through the networks. Every node, including source and intermediate nodes, has a fair opportunity to transmit a packet. Thus, the hot spot may suffer traffic congestion. The packet loss rate and the transmission delay are increased, but the throughput is decreased. Due to the contention for the shared channel, the throughput of each single node is limited not only by the channel capacity, but also by the transmissions in its neighborhood (intraflow/interflow contention problem). Furthermore, the network throughput still restrict by the channel capacity. Some other related works using multiple channels simultaneously to transmit packets without interfering each other increases the throughput. But if the traffic load is heavy, these schemes may induce more serious packet loss on the contrary because they do not consider the congestion problem especially in multihop MANETs. In this paper, we propose a new multichannel MAC protocol using multichannel transmission, and develop a hopby-hop congestion control scheme, which is named "Efficient Flow Control with Multichannels" (EFCM). The EFCM scheme modifies the IEEE 802.11 RTS/CTS frame format to reserve bandwidth in different channels. It also solves the hidden terminal problem in the multichannel environment. The intermediate nodes have a higher priority than the source (or leaf) nodes to contend for the right of transmission to solve the intraflow contention. In order to solve the interflow contention, congestion control is taken in every node to construct a flow table, which restricts the number of packets of every flow passing by congested nodes. According to the simulation results, the whole network throughputs of EFCM are improved significantly.