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

A knowledge-based system is described for boundary detection from magnetic resonance image sequences of a beating heart. It is shown that the Dempster/Shafer theory and fuzzy set theory can be used for control of the system as well as for labeling objects in the images. The quality of the images is measured for ordering the images in boundary detection. The performance of the various knowledge sources is evaluated for learning from experience. These approaches provide the system with top-down feedback functions that can be utilized for more efficient use of limited computational resources. The basic structure of the system and the function of each component is described. The performance of the components is presented with some examples. >

A system for knowledge-based boundary detection of cardiac magnetic resonance image sequences

We present a new oblivious digital watermarking method for copyright protection of still images The technique is based on decorrelating the image samples then embedding the watermark by taking block DCT of the decorrelated image Watermark insertion is obtained by amplitude modulating the DC component of the DCT blocks with the watermarking bits The technique shows satisfactory robustness to Stirmark benchmark test and other class of geometric deformations Image decorelation is achieved using a key to increase the security of the watermarking system The watermark is a readable sequence of binary digits channel encoded to increase its robustness against various types of attacks

Secure, blind image watermarking technique for copyright protection

This paper introduces a new algorithm for the restoration of black and white photographic images that have been distorted by linear blurs and additive noise. The algorithm is iterative and particularly efficient for one-dimensional causal distortions, such as motion blur, and one- and two-dimensional symmetric distortions, such as out-of-focus blurs. It involves solving sets of Toeplitz or block Toeplitz linear equations. The algorithm is illustrated using an example involving motion blur.

Efficient Algorithms for Least-Squares Restoration

A hierarchical coder (HC) is constructed from a number of simple coders for image blocks arranged in order of increasing bit rate and reproduction quality. This paper discusses several aspects of hierarchical coders, including: a general description of the structure of a HC, its advantages and important design considerations, a discussion of how threshold selection can affect the performance of the coder through a simple example, and an introduction of a simple procedure for selecting optimal (in the rate distortion sense) decision thresholds which control the levels of the hierarchy. >

Optimal threshold selection in hierarchical coders for images and video

A new computational approach is presented for the estimation of displacement fields along contours of moving regions in image sequences. The proposed scheme uses frame differences to determine moving edges, which are then expressed as straight line tokens. Finally, an edge propagation algorithm is used to determine the distance between these moving edge tokens and the frame difference region boundaries to approximate the displacement fields. The performance of the system is evaluated with a real video image sequence. >

Russell M. Mersereau

Papers

A system for knowledge-based boundary detection of cardiac magnetic resonance image sequences

Secure, blind image watermarking technique for copyright protection

Efficient Algorithms for Least-Squares Restoration

Optimal threshold selection in hierarchical coders for images and video

Displacement estimation along contours in image sequence analysis