Estimating forest parameters using Landsat ETM+ spectral responses and monocultured plantation fieldwork measurements data

Forest parameters, such as mean diameter at breast height (DBH), mean stand height (H) or volume per hectare (V), are imperative for forest resources assessment. Traditional forest inventory that is usually based on fieldwork is often difficult, time-consuming, and expensive to conduct over large areas. Therefore, estimating forest parameters in large areas using a traditional inventory approach combined with satellite data analysis can improve the spatial estimates of forest inventory data, and hence be useful for sustainable forest management and natural resources assessment. However, extracting practical information from satellite imagery for such purpose is a challenging task mainly because of insufficient knowledge linking forest inventory data to satellite spectral response. Here, we present the use of a cost-free Landsat-7 Enhanced Thematic Mapper Plus (ETM+) in order to explore whether it is possible to combine all available optical bands from a specific sensor for improving forest parameter spatial estimates, based on fieldwork at Lahav and Kramim Forests, in the Israeli Northern Negev. A generic strategy, based on morphological structuring element, convex hall and spectral band linear combination algorithms, was developed in order to extract the mathematical dependencies between the forest inventory measurements and linear combination sets of Landsat-7 ETM+ spectral bands, which yields the highest possible correlation with the forest inventory measured data. Using the mathematical dependency functions, we then convert the entire Landsat-7 ETM+ scenes into forest inventory parameter values with sufficient accuracy and tolerance errors needed for sustainable forest management. The root mean square error obtained between the measured and the estimated values for Lahav Forest are 0.70 cm, 0.29 m, and 1.48 m³ ha^?1 for the mean DBH, H, and V, respectively, and for Kramim forest are 0.61 cm, 0.70 m, and 6.31 m³ ha^?1, respectively. Furthermore, the suggested strategy could also be applied with other satellites data sources.     

Practical Thermal Multi–Scale Analysis for Composite Materials–Mechanical-Orientated Approach

This paper describes a thermal multi-scale formulation for composite materials based on a mechanical homogenization approach. The presented formulation evaluates the effective macroscopic thermal conductivity of the composite materials and also the microscopic heat flux field by scaling down to the micro-scale level. The effective thermal conductivity of the composite materials was calculated by applying the homogenization theory over the unit cell. The uniqueness of the presented multi-scale analysis related to the elastic problems solved at the microscopic scale (unit cell). This method has the advantage of applying periodic boundary conditions and uniform macroscopic temperature gradient over the unit cell. The proposed thermal multi-scale analysis was verified and its efficiency was demonstrated on large scale problem.     

Drilling Fluid Considerations in Design of Engineered Horizontal Directional Drilling Installations

A literature review is presented that identifies a number of areas where procedures for the engineering design of bored installations in soil using horizontal directional drilling (HDD) can be improved through a more realistic consideration of drilling fluid drag effects and skin friction coefficients. The current HDD practice of calculating annular frictional pressure loss caused by drilling fluid drag based on the assumption of concentric annular flow of a Bingham plastic fluid is demonstrated to be overly conservative. Consequently, critical design parameters, such as depth of cover, which affects crossing length, and drilling equipment size, which is selected based on anticipated pulling load, cannot be optimized. This can result in overly conservative design and unnecessary construction costs. Parameter values currently employed in HDD pulling load prediction are challenged suggesting that the viscous shear of drilling fluid is significantly less than typically quoted and that the friction coefficients often employed are not representative of all skin friction effects in HDD. A new real-time monitoring cell for large-scale HDD is described that can be used to optimize installations and to assess and update current prediction models.     

Error exponents of modulo-additive noise channels with sideinformation at the transmitter

Consider the optimum strategy for using channel state (“side”) information in transmission over a modulo-additive noise channel, with state-dependent noise, where the receiver does not have access to the side information (SI). Previous work showed that capacity-wise, the optimum transmitter shifts each code letter by a “prediction” of the noise sample based on the SI. We show that this structure achieves also the random-coding error exponent, and, therefore, is optimum at some range of rates below capacity. Specifically, the optimum transmitter predictor minimizes the Renyi entropy of the prediction error; the Renyi order depends on the rate, and goes to one (corresponding to Shannon entropy) for rates close to capacity. In contrast, it is shown that this “prediction strategy” may not be optimal at low transmission rates     

Least squares solutions of the HJB equation with neural network value-function approximators.

In this paper, we present an empirical study of iterative least squares minimization of the Hamilton-Jacobi-Bellman (HJB) residual with a neural network (NN) approximation of the value function. Although the nonlinearities in the optimal control problem and NN approximator preclude theoretical guarantees and raise concerns of numerical instabilities, we present two simple methods for promoting convergence, the effectiveness of which is presented in a series of experiments. The first method involves the gradual increase of the horizon time scale, with a corresponding gradual increase in value function complexity. The second method involves the assumption of stochastic dynamics which introduces a regularizing second derivative term to the HJB equation. A gradual reduction of this term provides further stabilization of the convergence. We demonstrate the solution of several problems, including the 4-D inverted-pendulum system with bounded control. Our approach requires no initial stabilizing policy or any restrictive assumptions on the plant or cost function, only knowledge of the plant dynamics. In the Appendix, we provide the equations for first- and second-order differential backpropagation.     

Quantification of social costs associated with construction projects: state-of-the-art review

Communities that surround an operating construction site often find themselves subjected to negative impacts such as annoyances and economic losses. The latter often called “social costs”, refer to the monetary equivalent of consumed resources, loss of income and loss of enjoyment experienced by parties not engaged in the contractual agreement, solely due to a construction process. Social costs take many forms including loss of revenue, productivity and time, consumption of non-renewable resources and accelerated deterioration of secondary roads.Social costs, while widely acknowledged, are rarely considered in the design, planning or bid evaluation phases of construction projects in North America. This is attributed to the difficulty associated with quantifying social costs using standard estimating methods and the fact that these costs are borne by the community rather than the contractual parties. This paper outlines 22 sources of social costs associated with construction projects in urban environments. The concept of ‘social indicators' is introduced as a mean to link adverse impacts generated by construction activities and valuation methods. Thereafter, seven methodologies developed in the fields of economics and actuary are presented and their suitability for quantifying specific classes of social costs associated with construction projects are investigated. The capacity of current bid evaluation methods to account for social costs is also examined. It is concluded that a methodical approach for the incorporation of social costs in the bid evaluation process will be a key step towards a more sustainable-oriented construction industry. A generic framework for the development of such an approach is presented. Finally, the concept of developing a standard reference document to estimate social costs is examined and a sample format proposed.     

Genetically engineered pfabA pfabR bacteria: an electrochemical whole cell biosensor for detection of water toxicity

We describe here a bacterial sensor for electrochemical detection of toxic chemicals. The sensor constitutes recombinant bacteria harboring plasmids encoding the fabA and fabR genes and has high-resolution amperometric response to membrane-damaging chemicals. For example, it can detect phenol at concentrations ranging between 1.6 and 16 ppm within 20 min. The high sensitivity is achieved by using the fabA promoter fused to a reporter gene-encoded beta-galactosidase on a low copy number plasmid, under the control of the FabR repressor. The use of electrochemical whole cell sensors enables sensitive, fast, easy to operate, and cost-effective detection of water toxicity threats.     

Spin-dependent plasmonics based on interfering topological defects

Observation of spin-dependent plasmonics based on the interference of topological defects in the near-field is presented. We utilize the surface plasmons' scattering dynamics from localized vortex sources to create spinoptical devices as an ensemble of isolated nanoantennas to observe a "giant" spin-dependent plasmonic vortex and a spin-dependent plasmonic focusing lens. The spin-orbit point spread function, a spiral wavefront, is introduced, where the optical spin is a degree of freedom.     

A close-to-capacity dirty paper coding scheme

The "writing on dirty paper"-channel model offers an information-theoretic framework for precoding techniques for canceling arbitrary interference known at the transmitter. It indicates that lossless precoding is theoretically possible at any signal-to-noise ratio (SNR), and thus dirty-paper coding may serve as a basic building block in both single-user and multiuser communication systems. We design an end-to-end coding realization of a system materializing a significant portion of the promised gains. We employ multidimensional quantization based on trellis shaping at the transmitter. Coset decoding is implemented at the receiver using "virtual bits." Combined with iterative decoding of capacity-approaching codes we achieve an improvement of 2dB over the best scalar quantization scheme. Code design is done using the EXIT chart technique.