Wireless distributed microsensor systems will enable the reliable monitoring of a variety of environments for both civil and military applications. In this paper, we look at communication protocols, which can have significant impact on the overall energy dissipation of these networks. Based on our findings that the conventional protocols of direct transmission, minimum-transmission-energy, multi-hop routing, and static clustering may not be optimal for sensor networks, we propose LEACH (Low-Energy Adaptive Clustering Hierarchy), a clustering-based protocol that utilizes randomized rotation of local cluster based station (cluster-heads) to evenly distribute the energy load among the sensors in the network. LEACH uses localized coordination to enable scalability and robustness for dynamic networks, and incorporates data fusion into the routing protocol to reduce the amount of information that must be transmitted to the base station. Simulations show the LEACH can achieve as much as a factor of 8 reduction in energy dissipation compared with conventional outing protocols. In addition, LEACH is able to distribute energy dissipation evenly throughout the sensors, doubling the useful system lifetime for the networks we simulated.

/pdf/energy-efficient-communication-protocol-for-wireless-4vhuagusz2.pdf

Energy-efficient communication protocol for wireless microsensor networks

Wireless distributed microsensor systems will enable the reliable monitoring of a variety of environments for both civil and military applications. In this paper, we look at communication protocols, which can have signicant impact on the overall energy dissipation of these networks. Based on our ndings that the conventional protocols of direct transmission, minimum-transmission-energy, multihop routing, and static clustering may not be optimal for sensor networks, we propose LEACH (Low-Energy Adaptive Clustering Hierarchy), a clustering-based protocol that utilizes randomized rotation of local cluster base stations (cluster-heads) to evenly distribute the energy load among the sensors in the network. LEACH uses localized coordination to enable scalability and robustness for dynamic networks, and incorporates data fusion into the routing protocol to reduce the amount of information that must be transmitted to the base station. Simulations show that LEACH can achieve as much as a factor of 8 reduction in energy dissipation compared with conventional routing protocols. In addition, LEACH is able to distribute energy dissipation evenly throughout the sensors, doubling the useful system lifetime for the networks we simulated.

Energy-efficient communication protocols for wireless microsensor networks

Determining optical flow

Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

An automated method for segmenting magnetic resonance head images into brain and non-brain has been developed. It is very robust and accurate and has been tested on thousands of data sets from a wide variety of scanners and taken with a wide variety of MR sequences. The method, Brain Extraction Tool (BET), uses a deformable model that evolves to fit the brain's surface by the application of a set of locally adaptive model forces. The method is very fast and requires no preregistration or other pre-processing before being applied. We describe the new method and give examples of results and the results of extensive quantitative testing against "gold-standard" hand segmentations, and two other popular automated methods.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/hbm.10062

Fast robust automated brain extraction

This work presents a joint source and channel coding method for transmission of progressively compressed three-dimensional (3-D) models where the bit budget is allocated optimally. The proposed system uses the Compressed Progressive Mesh (CPM) algorithm to produce a hierarchical bitstream representing different levels of detail (LODs). In addition to optimizing the transmitted bitstream with respect to the channel characteristics, we also choose the optimum combination of quantization and tessellation to maximize the expected decoded model quality. That is, given a 3-D mesh, a total bit budget (B) and a channel packet-loss rate (P/sub LR/), we determine the optimum combination of: 1) the geometry coordinates quantizer step size (l-bit); 2) the number of transmitted batches (L); 3) the total number of channel coding bits (C); and 4) the distribution of these channel coding bits among the transmitted levels (C/sub L/). Experimental results show that, with our unequal error protection approach that uses the proposed bit-allocation algorithm, the decoded model quality degrades more gracefully (compared to either no error protection or equal error protection methods) as the packet-loss rate increases.

Bit allocation for joint source and channel coding of progressively compressed 3-D models

Compressed video sequences are very sensitive to channel disturbances when they are transmitted through an unreliable environment such as a wireless channel. The transmission errors not only corrupt the current decoded frame, but also propagate to the succeeding frames. Many error concealment methods have been proposed to recover the errors by exploiting temporal and spatial correlation. In this paper, we develop a multi-frame boundary matching algorithm (MF-BMA), which utilizes the boundary smoothness property not only in the decoded frame but also in the succeeding frames. The experimental results demonstrate that the proposed algorithm can provide better performance, especially when horizontal edges exist across the lost macroblocks.

A temporal error concealment method for MPEG coded video using a multi-frame boundary matching algorithm

Ieee acoustics, speech, and signal processing society

The presence of optical turbulence in video acquired by cameras viewing scenes at long distances can contribute significantly to degradation. This problem arises routinely, for example, in astronomy where objects of interest reside beyond the earth's atmosphere. Optical turbulence introduces time-varying perturbations in the images as well as blurring. In this paper, we introduce a method for suppressing the effects of this turbulence to enhance the quality of the observed objects and scenes. The proposed method is based on a new form of adaptive control grid interpolation in which computed motion vectors are used as the basis for turbulence estimation and suppression. In particular, the quasi-periodicities of the turbulent motion are exploited in the algorithm, which allow them to be suppressed while true motion (such as panning and zooming) is preserved.

/pdf/a-new-method-for-suppressing-optical-turbulence-in-video-4g1zsrzbxv.pdf

A new method for suppressing optical turbulence in video

From the Publisher:
Utilizing classroom tested projects and exercises, this supplemental text and disk exposes advanced undergraduate and graduate students to digital signal processing (DSP) in a computer environment. These exercises and projects offer practical applications to real-world problems with easy modification to provide students with variety and fresh testing from year to year. The software is easy to use with an on-line help function which explains the usage of all DSP functions.

Russell M. Mersereau

Papers

Bit allocation for joint source and channel coding of progressively compressed 3-D models

A temporal error concealment method for MPEG coded video using a multi-frame boundary matching algorithm

Ieee acoustics, speech, and signal processing society

A new method for suppressing optical turbulence in video

Introduction to Digital Signal Processing: A Computer Laboratory Textbook