Microwave remote sensing of physically buried objects in the Negev Desert: implications for environmental research

We report remote detections of physically buried specularly reflecting objects using microwave radar at two sites: Ashalim and Tseelim in the northern region of the Negev Desert, Israel. These detections provide confirmation that microwave subsurface remote sensing is a genuine phenomenon. At Ashalim, a scatterometer operating in the P-band (441 MHz, 68 cm) was mounted on a cherry picker truck at a height of 8 m and used to detect two triangular aluminum mesh reflectors (forming a 1-m square area reflector) buried down to a depth of 8 cm in dry sand. At Tseelim, the same scatterometer was mounted on an airplane flying at an altitude of 70 m and used to detect 1-m square aluminum reflectors (each one submerged at a different location along the airplane flight path) buried down to a depth of 20 cm. The experimental results compare favorably with a theoretical model that incorporates radar absorption effects arising in the sandy subsurface layer and radar interference effects arising from phase differences between reflections from the surface and buried reflector. The theoretical modeling also predicts the detection of a subsurface reflector down to a depth of about 4.4 m. This experiment and the associated modeling approach is the first of a series of planned experiments, which we outline for the detection and the theoretical evaluation of buried reflectors using remote microwave and VHF radar. We identify potential subject areas for environmental research.     

Applying Plan Recognition Algorithms To Program Understanding

Program understanding is often viewed as the task of extracting plans and design goals from program source. As such, it is natural to try to apply standard AI plan recognition techniques to the program understanding problem. Yet program understanding researchers have quietly, but consistently, avoided the use of these plan recognition algorithms. This paper shows that treating program understanding as plan recognition is too simplistic and that traditional AI search algorithms for plan recognition are not suitable, as is, for program understanding. In particular, we show (1) that the program understanding task differs significantly from the typical general plan recognition task along several key dimensions, (2) that the program understanding task has particular properties that make it particularly amenable to constraint satisfaction techniques, and (3) that augmenting AI plan recognition algorithms with these techniques can lead to effective solutions for the program understanding problem.     

Observer matrix gain optimization for stochastic continuous time nonlinear systems

It is shown that for a class of stationary stochastic nonlinear systems (satisfying a global Lipschitz condition) the high-gain observer with a constant gain matrix may guarantee an upper bound for the averaged quadratic error of state estimation. The nonlinearity is assumed to be a priory known. The main contribution of this paper consists in designing of a numerical procedure for the optimal gain matrix minimizing this upper bound. The convergence analysis of this procedure is presented as well as an example illustrating its finite steps workability: it is shown that within a neighborhood of the optimal matrix gain the others provide lower estimation performance.     

Quality Improvement of Granular Wastes-The Effective Way to Recycle Secondary Raw Building Materials

1　IntroductionTherearefourmaintypesofgranularwastematerialslistedinTable 1.Constructionanddemolitionwaste(CDW )arefromtheconstruction ,remodelling ,repairinganddemolishingofbuildingsandotherstructures .Ashesaretheresiduesfromburningofwood ,coal ,andother…     

Interactions of sperm perinuclear theca with the oocyte: implications for oocyte activation,anti-polyspermy defense,and assisted reproduction

Perinuclear theca (PT) is the cytoskeletal coat of mammalian sperm nucleus that is removed from the sperm head at fertilization. PT harbors the sperm borne, oocyte-activating factor (SOAF), a yet-to-be-characterized substance responsible for triggering the signaling cascade of oocyte activation, thought to be dependent on intra-oocyte calcium release. The present article reviews the current knowledge on the biogenesis and molecular composition of sperm PT. Possible functions of sperm PT during natural and assisted fertilization, and in the initiation of embryonic development are discussed. Furthermore, evidence is provided that SOAF is transferred from the sperm PT to oocyte cytoplasm through the internalization and rapid solubilization of the post-acrosomal PT. It is shown that during natural fertilization the sperm PT dissolves in the oocyte cytoplasm concomitantly with sperm nuclear decondensation and the initiation of pronuclear development. SOAF activity is preserved in the differentially extracted sperm heads only if the integrity of PT is maintained. After intracytoplasmic sperm injection (ICSI), activation occurs only in those oocytes in which the injected spermatozoon displays complete or partial dissolution of PT. In the latter case, the residual PT of the sub-acrosomal and/or post-acrosomal sperm region may persist on the apical surface of the sperm nucleus/male pronucleus and may cause a delay or arrest of zygotic development. We propose that the sperm PT harbors SOAF in the post-acrosomal sheath, as this is the first part of the sperm cytosol to enter the oocyte cytoplasm and its disassembly appears sufficient to initiate the early events of oocyte activation. Dissolution of the sub-acrosomal part of the PT, on the other hand, appears necessary to insure complete DNA decondensation in the internalized sperm nucleus and initiate DNA synthesis of both pronuclei. The release of the SOAF from the sperm head into oocyte cytoplasm at fertilization ultimately leads to the activation of oocyte mechanism including the completion of the meiotic cell cycle, pronuclear development and anti-polyspermy defense.     

A reduction approach to the two-campus transport problem

The two-campus transport problem (TCTP) is a dial-a-ride problem with only two destinations. The problem is motivated by a transport problem between two campuses of an academic college. The two campuses are located in two different cities. Lecturers living in one city are sometimes asked to teach at the other city’s campus. The problem is that of transporting the lecturers from one campus to the other, using a known set of vehicles, so as to minimize the time the lecturers wait for their transport. We mathematically model the general TCTP, and provide an algorithm that solves it, which is polynomial in the number of lecturers. The algorithm is based on a reduction to a shortest path problem.     

Factors facilitating or impeding older adults’ creative contributions in the collaborative design of a novel DTV-based application

This article describes some of the challenges of supporting older adults’ creative input to the design of an (as yet) undefined digital television application. Focusing on commonly used brainstorming and paper prototyping techniques, constructive insights are gathered from users with limited experience of interactive technology. Encouraging older participants to move beyond what they are familiar with, the research reports on how fragmented conceptual knowledge of familiar technologies can either facilitate or impede the creative development of new ideas. This includes bias or contradictory ideas that can emerge in the elicitation process. As reported, other factors, such as the self-perception of inadequate drawing skills, demonstrate further barriers for some older adults to articulate their visions and aspirations for suitably designed technology.     

Synthesis and characterization of high molecular weight polyaniline for organic electronic applications

High molecular weight polyaniline (PANI) was synthesized by a combined procedure incorporating various synthesis methods. Temperature and open circuit potential of the reaction mixture were collected to monitor the reaction progress. The polymer is characterized by various techniques including gel permeation chromatography, dynamic light scattering, infrared spectroscopy, solid‐state nuclear magnetic resonance, and differential scanning calorimetry for elucidating the molecular architecture obtained by this method. As‐synthesized PANI was found to possess high molecular weight, reduced branching, reduced cross‐linking, and to predominantly consist of linear polymer chains. This polymer was also found to be more stable in solution form. J–V characteristics of as‐synthesized PANI films indicate a high current density which is due to increased free pathways and less traps for the charge transport to occur in PANI films. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers     

From experimental data,the mechanics relationships describing the behaviour of four different low alloyed steel powders during uniaxial cold compaction

This work aims at determining the constitutive model of four commercial water atomised low alloyed steel powders during cold compaction. Single-action experiments were performed, obtaining cylindrical specimens with different H/D ratios. The distribution of axial and radial stresses was investigated, and the relationships describing both the radial stress transmission coefficient and the flow stress as functions of the relative density were determined. The radial stress transmission coefficient also confirmed the hypothesised value of Poisson’s coefficient. The friction coefficient between the powder column and the die wall was determined, also highlighting the influence of the H/D ratio. Measuring the axial and radial strains due to spring-back, the axial and radial elastic moduli were determined, as functions of the relative density. The results obtained for the four materials were compared, also highlighting both differences and similarities.