Sharif Digital Repository

Ontology matching is a process for selection of a good alignment across entities of two (or more) ontologies. This can be viewed as a two-phase process of (1) applying a similarity measure to find the correspondence of each pair of entities from two ontologies, and (2) extraction of an optimal or near optimal mapping. This paper is focused on the second phase and introduces our evolutionary approach for that. To be able to do so, we need a mechanism to score different possible mappings. Our solution is a weighting mechanism named coincidence-based weighting. A genetic algorithm is then introduced to create better mappings in successive iterations. We will explain how we code a mapping as... 

Various methods using different measures have been proposed for ontology alignment. Therefore, it is necessary to evaluate the effectiveness of such measures to select better ones for more quality alignment. Current approaches for comparing these measures, are highly dependent on alignment frameworks, which may cause unreal results. In this paper, we propose a framework independent evaluation method, and discuss results of applying it to famous existing string measures. © Springer-Verlag Berlin Heidelberg 2006  

Predicting latency between nodes on the internet can have a significant impact on the performance of many services that use latency distances among nodes as a decision making input. Coordinate-based approaches are among the family of latency prediction techniques where latency between each pair of nodes is modeled as the virtual distance among those nodes over a virtual system. This article proposes the Decentralized Coordinate System (DCS) as a fully distributed system that does not rely on any infrastructure support from the underlying network. DCS uses a two-phase algorithm: first, each host is assigned rough coordinates, then, the rough estimation is refined in a way that it gradually... 

The mechanism of gold nanowire (AuNW) and nanotube (AuNT) electrodeposition in a cyanide-free solution is investigated for the first time based on the analytical model of Szabo et al. (A. Szabo et al., J. Electroanal. Chem. 217 (1987) 417) for recessed cylindrical ultramicroelectrode (UME). Track-etched Polycarbonate Template (PCT) is served as cylindrical UME ensemble/arrays. Firstly, Au is nucleated through a charge transfer step and when the Nernst thickness exceeds the pore length, the radial diffusion is established around pore mouths. By overlapping of these domains, the planar diffusion toward the whole PCT surface is obtained. An analytic expression for global diffusion coefficient... 

Gold nanotubes/nanowires (GNT/NW) were synthesized by using the template-assisted electrodeposition technique and mixed with castor oil-polyethylene glycol based polyurethane (PU) to fabricate porous composite scaffolds for biomedical application. 100 and 50 ppm of GNT/NW were used to synthesize composites. The composite scaffolds were characterized by Fourier transform infrared spectroscopy, dynamic mechanical thermal analysis, differential scanning calorimetry, and scanning electron microscopy. Cell attachment on polyurethane-GNT/NW composites was investigated using fat-derived mesenchymal stem cells. Addition of 50 or 100 ppm GNT/NW had significant effects on thermal, mechanical, and cell... 

Several metrics have been proposed for recognition of relationships between elements of two Ontologies. Many of these methods select a number of such metrics and combine them to extract existing mappings. In this article, we present a method for selection of more effective metrics - based on data mining techniques. Furthermore, by having a set of metrics, we suggest a data-mining-like means for combining them into a better ontology alignment  

predicting the latency between hosts in the internet can play a significant rolein the improvement of the performance of many services that use latency distances among hosts as a decision making input. Although, the information regarding the point to point delay among internet peers is required in many applications, such information is not easily available to the peers. Latency data acquisition requires a considerableamount of measurements to be performed at each node in order for that node to keep a recordof its latency to all the other nodes. Moreover, the measurements need to be regularly repeated in order to be updatedagainst the network dynamics where the latency values are frequently... 

This study attempts to find an optimum combination of the welding tool rotation rate (ω) and traveling speed (υ), concerning the corrosion and mechanical properties of Friction Stir Welded (FSWed) AA5052 Aluminum alloy. The effect of the tool speeds on the FSWed AA5052 are investigated via potentiodynamic polarization, open circuit potential (OCP) monitoring, test of the susceptibility to intergranular corrosion, weight loss, tension and micro-hardness tests. Optical microscope and Scanning Electron Microscopy (SEM) were employed for studying the morphology and analyzing the probable intergranular attacks. It was found that by increasing υ up to 200. mm/min at ω=400 rpm, the microstructural... 

The rapid growth of the world-wide web poses unprecedented scaling challenges for general-purpose crawlers and search engines. A focused crawler aims at selectively seek out pages that are relevant to a pre-defined set of topics. Besides specifying topics by some keywords, it is customary also to use some exemplary documents to compute the similarity of a given web document to the topic. In this paper we Introduce a new hybride focused crawler, which uses link structure of documents as well as similarity of pages to the topic to crawl the web © 2006 HEE  

Ontology Alignment is a process for finding related entities of different ontologies. This paper discusses the results of our research in this area. One of them is a formulation for a new structural measure which extends famous related works. In this measure with a special attention to the transitive properties, it is tried to increase recall with less harm on precision. Second contribution is a new method for compound measure creation without any need to the mapping extraction phase. Effectiveness of these ideas is discussed and quantitative evaluations are explained in this paper. Copyright © 2006, Hassan Abolhassani, Babak Bagheri Hariri, & Seyed H. Haeri  

Epoxy resins have been used as structural materials since the late 1940s. Despite their desirable properties such as high strength, excellent creep resistance, and good adhesion, they suffer from low fracture energy. Rubber modification as a major toughening approach to overcome the inherent brittleness of epoxy polymers was introduced during the early 1970s. Since then, a large number of investigations have been conducted to elucidate different aspects of rubber-toughened epoxies. The present work is a critical review of the field focusing on the important parameters affecting rubber-toughening. The studies reviewed are classified in five categories including roles of matrix ductility,... 

Periodic metallic structures are known to support resonant extraordinary optical transmission (EOT). When covered with graphene, these structures can be employed to effectively manipulate the light. In this paper, we propose an analytical circuit model for graphene-covered 1-D metallic gratings. By using the circuit theory, we demonstrate that 1-D periodic array of cut-through slits, which are covered by a continuous graphene sheet, exhibits tunable EOT resonance for TM polarization whose amplitude, unlike its spectral position, can be dynamically tuned by varying the Fermi level of graphene. In this fashion, it is shown that placing a perfect reflector at the bottom of the graphene-covered... 

A novel active queue management (AQM) method is proposed. This method, named NN-RED, is based on the use of a neural network for early congestion prediction. By simulations, it is demonstrated that the performance of the proposed approach is better than the random early detection (RED) method that is currently known as one of the best AQM methods in solving congestion problems. © The Institution of Engineering and Technology 2007  

Baseboard heaters are a type of building heating systems that are placed along the base of the interior wall, instead of the traditional skirting. Baseboard heaters meet all the requirements of modern buildings such as thermal comfort, well-architected appearance, space-saving, efficient energy consumption, and fast thermal response. In the present study, we investigate the enhancement of the thermal output of hydronic baseboard heaters. For this purpose, several novel fin-tube arrays such as convector fins and fin-clips are proposed and the thermal performance of each array is evaluated experimentally. In addition, two different types of materials for the tubes, namely, copper and aluminum... 

We experimentally demonstrate a circularly polarized antenna that utilizes unidirectional surface waves that propagate on the boundary of a small ferrite disk. The ferrite disk is metalized on top and is mounted on a grounded dielectric substrate. The disk is normally biased by a magnetic field that is provided by two permanent magnets below and above the structure. A two-section feeding network is used to feed the antenna. The operation frequency of the antenna can be adjusted by changing the magnitude of the applied magnetic bias. The sense of polarization can be reversed by reversing the direction of the applied bias. © 2020 Elsevier B.V  

The effect of the nucleating agent masterbatch carrier resin on the nonisothermal crystallization of a pipe-grade polypropylene block copolymer was investigated at three different cooling rates using differential scanning calorimetry (DSC). Bis(3,4-dimethylibenzylidene) sorbitol (DMDBS), a well-known, third-generation sorbitol derivative, was used as a nucleating agent in this study. Crystallization kinetic parameters obtained from DSC cooling curves showed that incorporation of a nucleating agent by means of a masterbatch increased the crystallization rate by approximately two times compared to that of the sample with the same concentration of nucleating agent without the use of a... 

Organisational commitment is suggested as a remarkable variable in shaping employees’ attitudes toward knowledge management practices. Customer trust in services is established during a long-time relationship with a firm and improves the accuracy of information shared with employees. To put it in other words, customer trust is what a service company needs to maintain its competitive advantage. On the other hand, high employee turnover reflects a substantial loss of knowledge. In the present study, the impact of organisational commitment on employees’ retention, knowledge acquisition, and sharing was examined regarding the moderating roles of leader-member exchange and innovation climate. The... 

Dimethylbenzylidene sorbitol (DMDBS) is a common nucleating/clarifier agent used in polypropylene (PP). So many researchers have looked at different aspects of incorporating this additive on the crystallization behavior of PP. The current study is focused on a rather new topic and that is the role of the carrier resin of DMDBS masterbatch on the rheological behaviour of polypropylene. This objective has been achieved through studying the role of the carrier resin on the phase separation behavior of DMDBS upon cooling. It has been shown that a permanent bond is formed between the molecules of carrier resin and DMDBS in the masterbatch and this bond slows down the crystallization kinetics of...