Parallel processing of graph reachability in databases

In this paper we consider parallel processing of a graph represented by a database relation, and we achieved two objectives. First, we propose a methodology for analyzing the speedup of a parallel processing strategy with the purpose of selecting at runtime one of several candidate strategies, depending on the hardware architecture and the input graph. Second, we study the single-source reachability problem, namely the problem of computing the set of nodes reachable from a given node in a directed graph. We propose several parallel strategies for solving this problem, and we analyze their performance using our new methodology. The analysis is confirmed experimentally in a UNIX-Ethernet environment. We also extend the results to the transitive closure problem.A preliminary shortened version of this paper has appeared inPDIS. See Ref. 1.This author's work was supported in part by NSF Grant 90-03341.This author's work was supported in part by the Natural Sciences and Engineering Research Council of Canada.This author's work was supported in part by NSF Grant 90-03341.     

Effect of Irradiation on Crystal Defects in Quartz

X-and ?-irradiation characteristics of optically non-clear natural quartz and electronic grade synthetic crystals have been investigated. In particular, it has been shown how, due to relatively large concentration of crystal imperfections in non-clear natural quartz, a positive frequency shift of crystal resonator on extended irradiation, increased smoky coloration, broad and sharp ESR signals observable at room temperature and increased intensity of thermoluminescence are produced compared to the corresponding characteristics of optically clear quartz crystals. It has been shown, how by increasing the imperfections in non-clear natural quartz still further by neutron irradiation, the frequency characteristics of natural quartz crystals would simulate those of the electronic grade synthetic crystals, and viceversa, by thermal annealing of the latter. Based on the appropriate thermal annealing of electronic grade synthetic crystals, the investigations yield a new way of achieving the much desired radiation hardening of quartz resonators used in satellite-borne frequency standards for space communication.     

Wettability of Al2O3, MgO,and TiB2 Inclusions with Liquid Silicon

Silicon - An experimental study was conducted to characterize the interaction between liquid silicon and refractory inclusions that are often present in silicon as solid inclusions. The...     

Effect of Aluminizing and Nitridation on the Oxidation Behavior of AISI 316LN SS

The application of stainless steel at temperatures above 973 K is rendered difficult by the chromium loss due to generation of volatile CrO₃ species and the consequent reduction in the capacity to maintain protective scale. We have attempted a method to circumvent this problem by modifying the surface. The surface was modified by three techniques each suiting a particular application. The first two methods involved aluminizing the surface by physical vapor deposition as the initial step. The pre-treatments were carried out in two ways viz. (i) high temperature diffusion-annealing and (ii) laser annealing of the surface. In the third method the specimen was modified by ion-nitriding. The oxidation behavior of these modified steels was compared with stainless steel in the as-received condition to exactly gauge the effect of surface modification. The oxidation experiment was carried out at 1123 K for 3.6 Ms. The oxidation was interrupted at specific time intervals to examine the mass change of the specimen and mass of the spalled oxide. The results indicated that aluminizing followed by heat-treatment and laser-treatment showed significant improvement in the adherence of the scale. On the other hand the bare and nitrided specimens showed similar behavior characterized by intermittent spallation and poor adherence. Nitriding resulted in the increase in the surface hardness. The post-oxidation examinations were carried out using SEM, EDAX and GIXRD. The uncoated specimen showed the presence of uniform oxide layer and contained oxides of iron and chromium. The aluminum-coated specimen showed the presence of adherent scale. The surface showed a nodular structure due to the formation of pits and zones of enhanced oxidation. The major part of the oxide was alumina with small fractions of chromium and iron oxides. The nodular region was enriched in the oxide of iron. The analysis of the surface by GIXRD revealed the nature of different phases formed on the surface. The oxide on the oxidized bare metal was Cr₂O₃, aluminized (non-oxidized) AlFe and Al₂Fe, aluminized and oxidized Al₂O₃ and FeCr₂O₄, aluminized and laser-treated Al₂O₃, FeCr₂O₄, Fe₂O₃ and Fe₃O₄, nitrided Fe₂O₃ and FeCr₂O₄. In the light of the above results the mechanism of scale failure has been proposed.     

Multiattribute decision making based on power operators for linguistic intuitionistic fuzzy set using set pair analysis

The aim of the presented paper is to give a multiattribute decision making (MADM) method under the linguistic intuitionistic fuzzy (LIF) environment using the set pair analysis (SPA) theory. LIF set can express the qualitative information in terms of linguistic variables, whereas the connection number (CN) based on the “identity,” “discrepancy,” and “contrary” degrees of the SPA theory handles the uncertainties and certainties systems. On the basis of these features, we develop some series of linguistic CN (LCN) power weighted and ordered weighted geometric aggregation operator to aggregate the different LCNs. Several properties of the operators are also studied. Afterward, we present a novel MADM method to solve decision‐making problems under LIF set environment and illustrate with several examples to validate it. A comparative analysis is also presented to show the results.     

Some results on information measures for complex intuitionistic fuzzy sets

Complex intuitionistic fuzzy sets (CIFSs), modeled by complex-valued membership and nonmembership functions with codomain the unit disc in a complex plane, handle two-dimensional information in a single set. Under this environment, the primary objective of the present study is to introduce some novel formulae of information measures (similarity measures, distance measures, entropies, and inclusion measures) and discuss the transformation relationships among them. To demonstrate the efficiency of the proposed similarity measures, we apply it to pattern recognition problem and a detailed comparative analysis is conducted with some of the existing measures. Further, algorithms based on proposed measures are developed for handing multicriteria decision-making problems and their working is illustrated with the help of an example. Besides this, the practicality of the proposed similarity measure is demonstrated by developing a clustering algorithm under CIFS environment.     

The case analysis on sentiment based ranking of nodes in social media space

Now-a-days, social network sites have become quite popular for communication in the society. People have entangled their day-to-day activities around social media platforms. Social Networks have allowed the users to share their opinions on different topics. In social media, sentiment analysis is an important character to determine opinions of users. Moreover, user’s can be ranked to determine their relative influence. This paper proposes a methodology to rank the users involving sentiment related parameters such as likes, comments and corresponding likescount. Analysis of users’ comments is carried-out. Weights are assigned to these parameters and scores are calculated for each user. Users are ranked on the basis of scores obtained and compared with existing technique. In order to verify the effectiveness of proposed methodology, data is extracted from a verified Facebook page ‘Panjab University, Chandigarh’. Mean, standard deviation and variance are computed to capture the usefulness of ranks obtained by the proposed method. Results depict that the proposed methodology is better than existing technique since it incorporates several features indicating positive and negative behavior of users. This technique can be used to determine the highly trusted and the most distrusted users in a social media user’s profile. Users with negative scores can be considered for outlier analysis. The proposed methodology can also be extended to work on other social media platforms.     

Some methods for strategic decision‐making problems with immediate probabilities in Pythagorean fuzzy environment

In this article, a new decision‐making model with probabilistic information and using the concept of immediate probabilities has been developed to aggregate the information under the Pythagorean fuzzy set environment. In it, the existing probabilities have been modified by introducing the attitudinal character of the decision maker by using an ordered weighted average operator. Based on it, we have developed some new probabilistic aggregation operator with Pythagorean fuzzy information, namely probabilistic Pythagorean fuzzy weighted average operator, immediate probability Pythagorean fuzzy ordered weighted average operator, probabilistic Pythagorean fuzzy ordered weighted average, probabilistic Pythagorean fuzzy weighted geometric operator, immediate probability Pythagorean fuzzy ordered weighted geometric operator, probabilistic Pythagorean fuzzy ordered weighted geometric, etc. Furthermore, we extended these operators by taking interval‐valued Pythagorean fuzzy information and developed their corresponding aggregation operators. Few properties of these operators have also been investigated. Finally, an illustrative example about the selection of the optimal production strategy has been given to show the utility of the developed method.     

A Novel Improved Accuracy Function for Interval Valued Pythagorean Fuzzy Sets and Its Applications in the Decision‐Making Process

The objective of this work is to present an improved accuracy function for the ranking order of interval‐valued Pythagorean fuzzy sets (IVPFSs). Shortcomings of the existing score and accuracy functions in interval‐valued Pythagorean environment have been overcome by the proposed accuracy function. In the proposed function, degree of hesitation between the element of IVPFS has been taken into account during the analysis. Based on it, multicriteria decision‐making method has been proposed for finding the desirable alternative(s). Finally, an illustrative example for solving the decision‐making problem has been presented to demonstrate application of the proposed approach.