An efficient and simple synthesis of some 2-amino-3-cyano-4H-pyran derivatives was developed by the one-pot and three-component reaction of aldehydes, ethyl acetoacetate, and malononitrile in the presence of ammonia as catalyst at room temperature. The reaction is rapid and clean, and gives the products in high yields.

The trend toward sustainable city development is associated with intelligent transportation systems (ITS). Automation, efficiency, safety, security, and cost-effectiveness are critical factors in establishing each aspect of a smart city. Real-time data obtained from ITS play an essential role in improving the level of service of road segments, enhancing road safety, and supporting road users with road circumstances information. Travel time information is applicable in travel time maps, decision makings for traffic congestion, dynamic pricing of the network, emergency relief services, traffic flow monitoring, traffic jams management, and air quality analysis. Travel time on a road segment highly depends on geometrical specifications, environmental and weather conditions, traffic flow, and driving behavior. Due to specific driving behavior and road conditions, the above parameters are not essentially applicable in another region. The present research uses the data collected from loop detectors and License Plate Recognition (LPR) systems to develop a Bureau of Public Roads (BPR) model for Iran’s freeway network (Tehran-Qom Freeway). Because of the large amount of data, the SQL server program was used for creating and organizing the database and the BPR model was calibrated using SPSS statistical software. The results of the BPR model were evaluated with an ANOVA test, indicating that the derived model can estimate the travel time at freeway sections with a %5.2 error for the volume-to-capacity ratio (V/C) of less than 0.8.

In this research, the influences of modal properties of a micro cubic satellite on equivalent static loads (due to combination of quasi-static and dynamic loads during launch time) have been studied. The study shows that the magnitude of equivalent static loads can be affected by satellite effective modes and effective mass distribution along natural frequencies. Besides, when to distinct launchers with different dynamic environments candidate for launch, analytical results illustrate that sometimes the equivalent static combined load value can be higher for the launcher with smaller quasi-static loads. This phenomenon is due to effective modal mass distribution of the satellite. Consequently, a higher combined load may be occurred during launch for smaller quasi-static conditions. Furthermore, in separation phase of satellite from the launcher, the satellite modal parameters influence the magnitude of applied shock load in both axial (launch) and lateral directions, importantly. Thus the present study yields reliable input values for separation shock test which considers dynamic properties of the satellite in comparison with some standards and launcher manuals, suggest a rough estimation of shock load, neglecting the satellite structure dynamic behavior.

In this article, an efficient, environmentally benign, solvent-free synthesis of diethyl-2,6-dimethyl-4-(1-phenyl-3-aryl-1H-pyrazol-4-yl)-1,4-dihydropyridine-3,5-dicarboxylates and their simple oxidative aromatization in presence of selected hypervalent iodine (III) reagents under solvent-free condition at room temperature is demonstrated. All reactions were carried out by grinding the reactant pyrazole substituted Hantzch-1,4-dihydropyridines and hypervalent iodine (III) reagent in a mortar with pestle. [Hydroxy(tosyloxy)iodo]benzene act as an more efficient oxidizing reagent in comparison to phenyliodine bistrifluoroacetate and iodobenzene diacetate in terms of reaction time and yields. The advantages of present protocol are the environment friendly, short reaction time, mild reaction conditions, and high yields of the products.

These days cyberattack is a serious criminal offense and it is a hotly debated issue moreover. A man-in-the-middle-attack is a kind of cyberattack where an unapproved outsider enters into an online correspondence between two users, remains escaped the two parties. The malware that is in the middle-attack often monitors and changes individual/classified information that was just real-ized by the two users. A man-in-the-middle-attack as a protocol is subjected to an outsider inside the system, which can access, read and change secret information without keeping any tress of manipulation. This issue is intense, and most of the cryptographic systems without having a decent authentication security are threatened to be hacked by the malware named ‘men-in-the-middle-attack’ (MITM/MIM). This paper essentially includes the view of understanding the term of ‘men-in-the-middle-attack’; the current work is mainly emphasized to accumulate related da-ta/information in a single article so that it can be a reference to conduct research further on this topic at college/undergraduate level. This paper likewise audits most cited research and survey articles on ‘man-in-the-middle-attack’ recorded on 'Google Scholar'. The motivation behind this paper is to help the readers for understanding and familiarizing the topic 'man-in-the-middle attack'.

Clustering is absolutely useful information to explore data structures and has been employed in many places. It organizes a set of objects into similar groups called clusters, and the objects within one cluster are both highly similar and dissimilar with the objects in other clusters. The K-mean, C-mean, Fuzzy C-mean and Kernel K-mean algorithms are the most popular clustering algorithms for their easy implementation and fast work, but in some cases we cannot use these algorithms. Regarding this, in this paper, a hybrid model for customer clustering is presented that is applicable in five banks of Fars Province, Shiraz, Iran. In this way, the fuzzy relation among customers is defined by using their features described in linguistic and quantitative variables. As follows, the customers of banks are grouped according to K-mean, C-mean, Fuzzy C-mean and Kernel K-mean algorithms and the proposed Fuzzy Relation Clustering (FRC) algorithm. The aim of this paper is to show how to choose the best clustering algorithms based on density-based clustering and present a new clustering algorithm for both crisp and fuzzy variables. Finally, we apply the proposed approach to five datasets of customer's segmentation in banks. The result of the FCR shows the accuracy and high performance of FRC compared other clustering methods.

The ready-to-wear sector is expanding quickly and already accounts for a significant contribution to Ethiopia's export revenue. Due to its lower labor and investment costs, availability of resources, government assistance, etc. than other sectors, this industry attracts young entrepreneurs from around the nation as investment destinations. However, while investing in the leather industry, there are frequently many more aspects to consider. Again, there are numerous leather investment opportunities in the leathers sector, including handbags, jackets, belts, shoes, gloves, etc. Different sorts of leather items necessitate various levels of capital investment, operator skill sets, and resource requirements, among many other things. Again, based on their capacity for managing businesses, available capital, business location, and other factors, not all investors are in the same position. To assist investors in making decisions on the opening of a new leather industry, this paper presents a FAHP methodology for choosing the best leather item among various possibilities in a fuzzy environment. The methods enable the decision-maker to incorporate language expressions of expert judgment into the evaluation process. Using the suggested process, the ideal leather item is chosen for the launching of a leather industry in Ethiopia under the current circumstances.

Parabolic leaf spring is one of the vital components in vehicle suspension system, and it is commonly used in heavy vehicles. It needs to have an excellent static load bearing capacity and fatigue life too. The purpose of this work is to make computer aided engineering (CAE) analysis of mono parabolic leaf spring and to see the effect of change of material in the optimized leaf. A mono steel leaf spring and a mono leaf spring made of composite material have been selected for this comparative analysis. The material of the mono steel leaf spring is EN45A and Glass Reinforced Plastic (GRP) as composite material which is having high strength to weight ratio. The mono leaf spring model is having one full length leave with eyes at both ends, two pins in each eye end and a rubber pad on the upper face of leave center. The CAD modelling of parabolic leaf spring has been done in CATIA and for analysis the model is imported in ANSYS workbench. It was shown that the use of composite material instead of steel resulted into large deflection, small variation in stresses and also a large amount of weight reduction.

The predominant tautomeric forms of N1–H, N2–H of 5-(2,6-dimethyl- and 5-(2,6-diisopropylphenoxy)-(1H)-tetrazoles were analyzed at B3LYP method using 6-311G(d,p) basis set in the gas phase. The N1–H form of tetrazoles was found to be more stable than N2–H form in both solid and gas phases. Crystal structures of both tetrazoles show an intermolecular H-bond between N1-H and N4 atom of other tetrazole space. The hydrogen bonds between each tautomer of tetrazoles were evaluated at B3LYP/6-311G(d,p) level. The geometrical parameters and spectral data of tetrazoles and their variation were studied in both solid and gas phases.

A search engine is an essential tool in our daily life. With the development of society and net-work technology, the users’ requirement of Internet information is increasing. For most search methods, keyword searching is in a crucial position. However, what about the quality of key-word search in different search engines? This paper evaluates the quality of keyword searching among different search engines project.