Constructing Multilevel Metadata Networks for Sharing Dispersed and Transient Information in a Mobile Environment

An intelligent multi-user mechanism has been prototyped at the Information System Collaboratory of the Pennsylvania State University, which is capable of resolving global queries with differing and overlapping information needs, spatial scalability and temporal assumptions. The sources of information for this prototype are mechanical damage monitoring sensors embedded in equipment at plant sites, on-board ships or aircrafts, archived historical and diagnostic databases like those available through NALCOMIS (NAVMASSO document J-004 EM-001C, 1995) logistics and maintenance databases at depots, interactive electronic technical manuals stored in databases, dynamic models of damage, and models of operational performance. The concept-of-operation includes mobile access to this information by equipment maintainers on-board ships, aircrafts and other mobile platforms. Real-time interoperation of these system components and databases, under dynamic equipment operating conditions of thermo-mechanical and environmental stress, requires complex interactions of internal representations of sensor data, performance requirements, resources and equipment models, with rich semantics. To support such interactions, following the work of Bright, Hurson and Pakzad (Bright, Hurson, and Pakzad, Transactions on Database Systems, Vol. 19, No. 2, pp. 212–253, 1994) local schema terms of available data sources are organized as the leaf nodes in a semantic network of metadata. The physical nodes of the network are partitioned into a top-down multi-level search control structure of increasing precision and decreasing semantic aggregation. Each physical node supports search through all lower layers of metadata in connected tree configurations. The resulting multilayered semantic network is modeled as a Thesaurus of terms T and relationships R. A relationship in R may be crisp or fuzzy. The DTIC (Defense Technical Information Center) thesaurus for equipment maintenance was used as a starting point in this work. It was further enhanced by application specific terms and endowed with a distance function. This distance function is used to formulate user adaptable Graphic User Interfaces (GUI) for making quality of service tradeoffs in the resolution of global queries.Step-by-step construction of the thesaurus as a multilevel metadata network, its scalability, dynamic adaptation through usage, and tolerance of semantic imprecision in query resolution are discussed in this paper. Furthermore, performance metrology for evaluating quality of service in global query resolution is also developed (Phoha, in Proceedings of the NIST Workshop on Advancing Measurements and Testing for Information Technology, Gaithersburg, MD, Oct. 1998).This work was funded by DARPA for the past four years under grant DE-FC36-94G010064, for establishing a National Information Infrastructure Testbed for Electronic Commerce in equipment health monitoring, failure diagnosis and prognosis services.     

Iron(III)-mediated ATRP systems of n-docosyl acrylate with AIBN and BPO

Well-defined poly(n-docosyl acrylate) (PDA) with narrow molecular weight distribution has been synthesized by atom transfer radical polymerization (ATRP) and reverse ATRP of n-docosyl acrylate (DA) at 80 °C in N,N-dimethylformamide using the carbon tetrabromide/FeCl₃/2,2′-bipyridine (bpy) initiation system in the presence of 2,2′-azobisisobutyronitrile (AIBN) and benzoyl peroxide (BPO) as the source of reducing agent. The rates of polymerization for both the systems exhibit first-order kinetics with respect to the monomer, however, peroxide-initiated system shows slow rate of polymerization as compared to the azo-system. The effect of various reaction parameters on number average molecular weight (M _n ) and molecular weight distribution (M _w/M _n ) have been investigated. The resulting PDA that obtained in presence of AIBN and BPO systems has been compared for both the conventional and reverse ATRP. The reverse ATRP initiated by peroxides behaves differently than that of the azo initiators. In reverse ATRP with BPO, the rate of polymerization (R _p) has been significantly increased with the increase of BPO resulting higher M _n and broader M _w/M _n . The reverse ATRP of DA did not exhibit living characteristics with BPO system. PDA has been characterized by GPC, FTIR, and NMR spectroscopy.     

Tactile Sensing—From Humans to Humanoids

Starting from human “sense of touch,” this paper reviews the state of tactile sensing in robotics. The physiology, coding, and transferring tactile data and perceptual importance of the “sense of touch” in humans are discussed. Following this, a number of design hints derived for robotic tactile sensing are presented. Various technologies and transduction methods used to improve the touch sense capability of robots are presented. Tactile sensing, focused to fingertips and hands until past decade or so, has now been extended to whole body, even though many issues remain open. Trend and methods to develop tactile sensing arrays for various body sites are presented. Finally, various system issues that keep tactile sensing away from widespread utility are discussed.      

Groundwater Flow and Contaminant Transport Simulation with Imprecise Parameters

A methodology has been developed in this study wherein a genetic algorithm (GA) is used to find a global optimal solution to a groundwater flow and contaminant problem by incorporating an artificial neural network (ANN) to evaluate the objective function within the genetic algorithm. The study shows that an ANN-GA technique can be used to find the uncertainties in output parameters due to imprecision in input parameters. The ANN-GA methodology is applied to five case studies involving radial flow in a well, one-dimensional solute transport in steady uniform flow, a two-dimensional heterogeneous steady flow, a two-dimensional solute transport, and a two-dimensional unsteady groundwater flow to demonstrate the efficiency and effectiveness of the developed algorithm. The results show that, with this approach, one can successfully measure the uncertainty in groundwater flow and contaminant transport simulations and achieve a considerable reduction in computational effort when compared to the vertex method that has been widely used in the past.     

Proteomics analysis of carbon-starved Mycobacterium smegmatis: induction of Dps-like protein

Mycobacterium tuberculosis is a globally successful pathogen,infecting more than one third of total world's population. Thesebacteria have the remarkable ability to persist in the hostfor long periods of time unrecognized by the immune system andthen to re-emerge later in life causing the disease. The physiologyof such persistent or dormant bacilli is not very well characterized.Some evidence suggests that the dormant bacilli survive in anutrient-deprived state that is similar to the stationary phaseof the bacteria with respect to gene expression and physiology.Under this assumption we have studied the survival of Mycobacteriumsmegmatis in carbon starvation conditions as a model for mycobacterialpersistence. M.smegmatis, being a fast-growing strain, servesas a good model to study starvation responses. Using the two-dimensionalelectrophoresis-based proteomics approach, we identified a proteinwhich was found to be expressed preferentially under starvationconditions. This protein is homologous to a family of proteinscalled Dps (DNA binding Protein from Starved cells) that areknown to protect DNA under various kinds of environmental stressesand its existence has, so far, not been reported in mycobacteria.Upon expression and purification of this protein, we observedthat it has non-specific DNA-binding ability. Formation of acage-like dodecamer structure is a characteristic feature ofDps. Using comparative modelling we were able to show that Dpsfrom M.smegmatis could form a dodecamer structure similar tothe crystal structure of Dps from Escherichia coli.     

Implementing a Manufacturing Information System

The adoption of a computer-driven technology should lead to cost reduction, improved control, and increased profitability. However, it should not be adopted just because it has worked well in other organizations. The corporate staff groups, in their zeal to please management, often lose objectivity and plunge into the new system adoption process to the detriment of the organizational welt-being. This article discusses the advantages of implementing a manufacturing information system to help MIS managers coordinate a strategy for CIM - computer-integrated manufacturing.     

An animal model of Peyronie's-like condition associated with an increase of transforming growth factor beta mRNA and protein expression

PURPOSE: Transforming growth factor beta (TGF-beta) is involved in numerous vital processes including tissue fibrosis. Our objective was to study the role of TGF-beta in the induction of a Peyronie's-like condition and to produce an animal model for the further study of Peyronie's disease. MATERIALS AND METHODS: Twenty-four adult male Sprague-Dawley rats were divided into two groups. Different concentrations of cytomodulin, a synthetic heptopeptide with TGF-beta-like activity, were injected into the tunica of each rat from the first group (n = 18). Rats in the second group (n = 6) received saline injections as a control. The tunical tissues were taken after 3 days, 2 weeks, and 6 weeks and were examined using Hart and Trichrome stains. In the same tissue samples, TGF-beta mRNA and protein expression were studied. RESULTS: Histological alterations were observed in 15 out of 18 cytomodulin-injected rats, especially in tissue examined after 6 weeks. The most prominent changes were chronic cellular infiltration, focal and diffuse elastosis, thickening, disorganization and clumping of the collagen bundles. Results from immunoblot revealed remarkable TGF-beta1 protein expression in all the cytomodulin-injected rats only after 2 and 6 weeks. No remarkable TGF-beta2 or TGF-beta3 protein expression was observed. TGF-beta1 mRNA expression in the cytomodulin-injected rats was noticed in rats injected with higher concentrations after 3 days, while it was expressed in all rats after 2 weeks. There was no expression in the control group after either 3 days or 2 weeks. CONCLUSIONS: Cytomodulin can induce Peyronie's-like condition in the rat penis, which may explain the role of TGF-beta in the pathogenesis of Peyronie's disease.     

Ultrasonic study of silver nanoparticles for various applications

ABSTRACT

Acoustic properties of aqueous solution of AgNO₃ at various concentrations, in presence of Tannic Acid at a fixed concentration (1 × 10^?4 M/L) are studied by ultrasonic method. Tannic acid, a compound derived from plant extracts, is used as the reducing and stabilizing agent to synthesize Ag-NPs and also enables variation of the mean size of Ag-NPs by taking a suitable concentration ratio of AgNO₃ and Tannic acid in distilled water. Ag-NPs are synthesized at room temperature and further stabilized with the aid of sonication. The temperature dependence of acoustic properties is studied and discussed in this paper. Acoustic properties were measured using multi-frequency nano fluid interferometer. It is found that there is a systematic increase in ultrasonic velocity upto 60 ^oC for almost all the concentrations studied and thereafter its value decreases, while this velocity decreases with increasing concentration of AgNO₃ in solution at higher concentrations only. This study is important to find optimum concentration required for a particular application. The present result will be useful as data for various applications.     

Compressive deformation behavior of Al 2024 alloy using 2D and 4D processing maps

The hot deformation behavior of Al 2024 was studied by isothermal hot compression tests in the temperature range of 250–500 °C and strain rate range of 10⁻³ to 10² s⁻¹ in a computer-controlled 50 kN servo-hydraulic universal testing machine (UTM). The results show that the flow stress of Al 2024 alloy increases with strain rate and decreases after a peak value, indicating dynamic recovery and recrystallization. The processing map exhibits two domains of optimum efficiency for hot deformation at different strains, including the low strain rate domain at 500 °C and between 10⁻² and 10⁻¹ s⁻¹ and the high strain rate domain in 250 and 300 °C in the strain rate range of 10¹ to 10² s⁻¹. An attempt has been made in this article to generate a new hybrid 4D process map which illustrates contours of power dissipation and instability in the 3D space of strain rate, temperature, and strain.