PGSW-OS: a novel approach for resource management in a semantic web operating system based on a P2P grid architecture

A web operating system is an operating system that users can access from any hardware at any location. A peer-to-peer (P2P) grid uses P2P communication for resource management and communication between nodes in a grid and manages resources locally in each cluster, and this provides a proper architecture for a web operating system. Use of semantic technology in web operating systems is an emerging field that improves the management and discovery of resources and services. In this paper, we propose PGSW-OS (P2P grid semantic Web OS), a model based on a P2P grid architecture and semantic technology to improve resource management in a web operating system through resource discovery with the aid of semantic features. Our approach integrates distributed hash tables (DHTs) and semantic overlay networks to enable semantic-based resource management by advertising resources in the DHT based upon their annotations to enable semantic-based resource matchmaking. Our model includes ontologies and virtual organizations. Our technique decreases the computational complexity of searching in a web operating system environment. We perform a simulation study using the Gridsim simulator, and our experiments show that our model provides enhanced utilization of resources, better search expressiveness, scalability, and precision.     

Developments in denture teeth to prevent softening by food solvents

The effect of various food-simulating solvents on the hardness of denture teeth after varying storage times, using a Martens hardness test was determined. Martens hardness (HM) was assessed at baseline and during storage up to 1 month in distilled water (DW), peppermint oil (PO), heptane (HT) and 75% ethanol (ET) for four commercially-available denture teeth; Vivodent (VIV), Double-cross-linked Postaris (DCL), Orthosit (ORT), Candulor porcelain (POR) and two polymer based experimental denture teeth: Experimental 1 (EXP1); a hybrid nanocomposite with two different sized silanated filler particles and Experimental 2 (EXP2); containing an organic copolymer based upon urethanedimethacrylate and polymethyl methacrylate. Hardness [mean (sd)] at baseline was: VIV 142 (1), DCL 142 (1), ORT 209 (9), POR 2926 (101), EXP1 285 (11), and EXP2 146 (12). One-way ANOVA using Tukey’s test on polymer-based materials showed that the hardness values of ORT and EXP1 were significantly higher than those of VIV, DCL and EXP2 (P < 0.05). Moreover, EXP1 had a significantly higher hardness value than ORT (P < 0.05). Except for EXP1, all polymer based materials showed a significant drop in hardness after storage in ET (P < 0.05). Specimens stored in water, heptane and peppermint oil showed minor fluctuations in hardness, which were not statistically significant.     

Strength Properties of Hexametaphosphate Treated Soils

The present technical note focuses on the potential application of sodium hexametaphosphate (HMP) in geo-environmental engineering. HMP may have many applications in geotechnical and geo-environmental engineering such as: improvement and stabilization of tailing dams, rehabilitation of old landfills, construction of new clay liners, containment and permeable barriers, etc. In this technical note, it is observed that the strength of silty-clayey sand containing a high concentration of metals (like tailings) is increased by mixing of HMP. On the other hand the strength of the kaolinite clay that may be used during the construction of a liner has been reduced by mixing with HMP. In order to study the influence of HMP, soil mixtures with various amount of HMP are prepared to conduct unconfined compression tests. The strength of the HMP-treated kaolinite specimens is always less than the kaolinite specimens for four weeks. HMP has decreased the strength of silty sand during the first days. However, the cations in the soil (specially Ca and Fe) may lead to precipitation and sorption mechanism to govern and, therefore, the strength increases noticeably up to 740%.     

Fracture strength and toughness of some phenolic concretes

The strength and toughness of a range of phenolic resin based concretes have been evaluated as a function of matrix resin type, content and catalyst ratios. Two resin systems were examined using resin: filler ratios of 4:1, 5: 1, 6:1, 7: 1 and 8: 1 by weight. Catalyst ratios were varied between 4 and 10% by weight of total resin. Through grading mixes were designed using four single sized silica sands of nominal particle sizes 2.4 and 1.2 mm and also 600 and 300 m in combination with a microfiller with a maximum particle size of 150 m. Gap gradings were also produced using two of the sand components (1.2 mm and 300 m) and the microfiller. Microfillers employed included silica flour, china clay and spheriglass 5000. Strength ranged from 4.7 to 7.9 MPa measured in axial tension and 21.3 to 31.4 MPa measured in flexure using four point bending. Fracture toughness, evaluated as the critical strain energy release rate, G,,, was determined using precracked double torsion specimens. Typical values ranged from 0.13 to 0.22 kJ m^–2.[/p]     

Modification of rice hull and sawdust sorptive characteristics for remove heavy metals from synthetic solutions and wastewater

In this work two modified agricultural residues, rice hull and sawdust were examined as sorbents to remove heavy metals Pb(II), Cd(II), Zn(II), Cu(II) and Ni(II) from synthetic solutions or wastewater samples. To modify their sorptive characteristics, samples were treated with HCl, NaOH and heat. The sorption of the heavy metals from the synthetic solutions was increased with pH and initial concentration. In pH 5, Pb(II) and Cd(II) showed the highest sorption and Cu(II), Zn(II) and Ni(II) showed the following orders, respectively. Sorption capacity of rice hull was higher than sawdust. The modifications changed the sorption capacity of the natural sorbents in the following order base>heat>natural>acid. The sorption isotherms of sorbents were best described by the Freundlich and Langmuir models. The basic treated rice hull and sawdust followed by the heat treated rice hull sorbed the maximum of heavy metals from the industrial wastewater samples. In the column experiment, the synthetic solutions and the wastewater samples gave almost the same results as the suspensions. The recovery of the columns using water and HCl showed positive results. Commercial sorbents removed Pb(II), Zn(II) and Ni(II) a little more than rice hull.     

Patch-based offline signature verification using one-class hierarchical deep learning

International Journal on Document Analysis and Recognition (IJDAR) - Automatic processing of offline signature verification (in general) can be considered as a low-cost solution to problems in...     

Probabilistic slope stability analysis in Kahrizak landfill: effect of spatial variation of MSW’s geotechnical properties

Bulletin of Engineering Geology and the Environment - The geotechnical properties of municipal solid waste (MSW) in landfills vary considerably depending on the composition, time, and the rate of...     

Effect of zeolitic metal–organic framework on thermal,mechanical, and electrical properties of Ca/Zn-stabilized polyvinyl chloride

In order to enhance the heat stability of polyvinyl chloride (PVC), several heat stabilizing parameters such as metal content, antioxidant percentage, primary-to-secondary antioxidant ratios, stearic-to-acetylacetonate ratio, the amounts of pentaerythritol and β-diketone were studied using oven and Congo red tests. Results indicated that the percentage contribution of the calcium-to-zinc molar ratio in the static heat stability was 60.78%. Due to the synergistic effects of the calcium/zinc stabilizer and the zeolitic metal–organic framework (MOF) as an effective co-stabilizer, the heat stability was increased from 109 to 148 min. The EDX analysis was carried out to determine the mechanism of HCl gas absorption by the zeolitic imidazolate framework-8 (ZIF-8) existing in the PVC compound. Furthermore, the Ca/Zn thermal stabilizer showed poor electrical insulating properties, but the ZIF-8 improved electrical resistivity of the PVC compounds. Volume resistivity of ZIF-8 was significantly higher than that of the commonly used Ca/Zn stabilizers. Dynamic mechanical thermal analysis and tensile test of the PVC compound containing the ZIF-8 showed increased T_g and enhanced toughness.     

Resource Allocations for Ultra-Reliable Low-Latency Communications

Ultra-reliable low-latency communications (URLLC) is a new feature to be considered for the fifth generation (5G) cellular systems. This feature is essential for the support of envisioned mission-critical applications, particularly in the realm of machine-type communications. These applications require that the messages, which are generally short-length packets, to be exchanged between a source and a destination with the high level of reliability and within a short period of time. The characteristics of URLLC do not fit directly in the conventional communication models. For instance, most of the existing communication models are developed considering moderate levels of reliability, neglecting the small effects of the feedback errors. However, even such small errors cannot be ignored for URLLC. This paper proposes a communication model for URLLC considering the reliabilities of both data and control channels. Then, the optimal and sub-optimal resource allocations are derived. We show that the proposed sub-optimal resource allocations have lower computational complexities with a negligible performance degradations compared to that of the optimal solutions. The results reveal that the possibility of performing only one retransmission can significantly reduce the required radio resources needed for data delivery compared to the case of performing a single transmission round.