An improved cuckoo search optimization algorithm with genetic algorithm for community detection in complex networks

This paper improved Cuckoo Search Optimization (CSO) algorithm with a Genetic Algorithm (GA) for community detection in complex networks. CSO algorithm has problems such as premature convergence, delayed convergence, and getting trapped in the local trap. GA has been quite successful in terms of community detection in complex networks to increase exploration and exploitation. GA operators have been used dynamically in order to increase the speed and accuracy of the CSO. The number of populations is dynamically adjusted based on the amount of exploration and exploitation. Modularity objective function (Q) and Normalized Mutual Information (NMI) is used as an optimization function. It was carried out on six types of real complex networks. The proposed algorithm was tested with GA, Artificial Bee Colony (ABC), Grey Wolf Optimizer (GWO), and CSO, with different iterations in modularity and NMI criteria. The results show that in most comparisons, the proposed algorithm has been more successful than the basic comparative algorithms, and it has proven its superiority in terms of modularity and NMI. The proposed algorithm performed an average of 54% better in modularity and 88% in NMI than other algorithms. It performed on average in modularity criteria 84.3%, 58.8%, 33.7% and 38.8%, respectively, compared to CSO, ABS, GWO and GA algorithms, and in terms of NMI index, 188.7%, 39.1%, 52.3% and 73.8%, respectively in CSO, ABS, GWO and GA algorithms performed better.

     

Investigation of kinetics and cracked oil structural changes in thermal cracking of Iranian vacuum residues

Two vacuum residues obtained from Iranian Tehran and Bandar Abbas refineries (T-VR and B-VR) were thermally cracked under various operating conditions (soak time and temperature). The yield distribution of the products and the alteration of the physical properties of the liquid products were evaluated in terms of a change in the operating conditions or the feedstock. It was found that, especially, at higher severities, T-VR tends to give higher yields of liquid product and a lower yield of residual product in comparison with B-VR. The average viscosity, density, refractive index, and molecular weight increased and the H/C ratio decreased upon raising temperature for the cracked oils obtained from both of the feedstocks. The integrals derived in quantitative NMR experiments are suggested to be used as a basis for calculation of paraffinic, olefinic, naphthenic, and aromatic portions of a hydrocarbon sample. The effects of temperature, residence time, and feed type on the composition of the cracked oils are thoroughly investigated on the basis of detailed carbon and proton spectra. A three-lump kinetic model is presented to determine the yields of gas, liquid, and (semi)solid in the upgrading process at hand. The unconvertible portion of the solid is proposed to represent coke or fouling tendency for the residue feedstocks.     

Customer oriented enterprise IT architecture framework

Due to the rapid expansion and complexity of mechanisms, technologies, systems, processes and communications in organizations, governance and management has become something beyond the control of hardware and software systems and include integration and convergence of all components of an organization. Enterprise architecture (EA) by breaking down the organization’s systems to its components and determining the relationship between them in different layers offers an appropriate solution for understanding and investigating relationships and processes of organizations which develop strategies and information technology plans. This paper proposes a conceptual model for enterprise IT architecture. For this purpose, conceptual and reference models of enterprise architecture are investigated and key concepts of them are described. By identifying dimensions of reviewed models, key dimensions of the proposed model are extracted and by using Shannon’s entropy, weight and priority of each dimension is determined. In order to determine building blocks of each dimension, a mapping has been established between customer and functional requirements by using axiomatic method and relations between customer and functional requirements has been validated by experts’ opinions using Quality Function Development (QFD) method. Proposed model has been described by determining goals, components and relations. Then the model is validated by surveying experts. Finally an Iranian telecommunication enterprise is selected for a case study and the model is tested there and promoting solutions are proposed to improve the status of the organization for implementing the model.     

Information Technology Knowledge Sharing Using Case-Based Reasoning

In the relatively short time since the first case-based reasoning systems were implemented, there have been numerous academic CBR demonstrators. CBR systems have been used in diagnosis of diseases, planning, legal reasoning, software design, arbitration, weather forecasting, tutoring, and help desk operations, to name a few.