Vertex-degree-based molecular structure descriptors of benzenoid systems and phenylenes

Several recently published papers report expressions for various vertex-degree-based molecular structure descriptors of benzenoid systems and phenylenes. We deduce here the general expression for these descriptors, and show that a simple and generally valid relation exists between such structure descriptors of phenylenes and their hexagonal squeezes

Monetary Integration in Europe in the Function of Fostering International Business

Through joining the European Economic and Monetary Union a heterogeneous influence of member states cannot be avoided but all countries follow the logic of the economic benefits of unification. Besides reducing transaction costs, greater transparency in prices and the elimination of the uncertainty of exchange rate fluctuations, there is a great impact of open borders on increasing trade between member states. Therefore in this article we will analyze the Andrew Rose effect which estimated that countries with same currency trade over three times as much with each other as countries with different currencies. Through objective and systematic analysis we well conclude that the positive effect of monetary integration on increasing of international trade should be carried out in absolute and relative terms. This work is licensed under a&nbsp;Creative Commons Attribution-NonCommercial 4.0 International License.</p

Monetary Integration in Europe in the Function of Fostering International Business

Through joining the European Economic and Monetary Union a heterogeneous influence of member states cannot be avoided but all countries follow the logic of the economic benefits of unification. Besides reducing transaction costs, greater transparency in prices and the elimination of the uncertainty of exchange rate fluctuations, there is a great impact of open borders on increasing trade between member states. Therefore in this article we will analyze the Andrew Rose effect which estimated that countries with same currency trade over three times as much with each other as countries with different currencies. Through objective and systematic analysis we well conclude that the positive effect of monetary integration on increasing of international trade should be carried out in absolute and relative terms. This work is licensed under a&nbsp;Creative Commons Attribution-NonCommercial 4.0 International License.</p

Waveguide Bandpass Filters for Millimeter-Wave Radiometers

A fundamental requirement for most mm-wave heterodyne receivers is the rejection of the input image signal which is located close to the local oscillator frequency. For this purpose we use a bandpass filter, which for heterodyne receivers is also called an image rejection filter. In this paper we present a systematic approach to the design of a waveguide bandpass filter with a passband from 100 to 110 GHz and upper rejection bandwidth in the range from 113 to 145 GHz. We consider two non-tunable filter configurations: the first one is relatively selective with 11 sections (poles) whereas the second one is simpler with 5 sections. We used established design equations to propose an initial guess for the geometries of the filters, optimized the geometries, constructed the filters using two different milling methods, measured their transmission and reflection characteristics, and compared the measurements with numerical simulations. Measurements of both filters agree well with simulations in frequency response and rejection bandwidth. The insertion loss of the 11-pole filter is better than 10 dB and that of the 5-pole filter is better than 5 dB. The 11-pole filter has a sharper attenuation roll-off compared with the 5-pole filter. The upper out-of-band rejection is better than 40 dB up to 145 GHz for the 11-pole filter and up to 155 GHz for the 5-pole filter

TESTING THE ATTITUDE TOWARD THE USE OF E-COMMERCE BASED ON THE CUSTOMER’S EDUCATIONAL LEVEL: THE CASE OF THE REPUBLIC OF SERBIA

The subject of this paper is to examine to what extent and in which way educational level influences the use of e-commerce in the Republic of Serbia, as well as, in part, to examine customer satisfaction with e-commerce. The main objective of this paper is to determine the level of customer use of e-commerce depending on their educational level, as well as to spot the areas which need to be improved in order to increase the degree of use of e-commerce in the Republic of Serbia. For the purposes of sorting and grouping the data in this study the statistical method has been used. All collected data were processed in the statistical software SPSS (descriptive and parametric analyses were used, as well as comparison of mean values, correlation and regression). Based on the results of the tests conducted it is to conclude that the respondents generally use e-commerce in Serbia on a small scale and that other technological advances are accepted to a greater extent than e-commerce. The respondents have very low confidence while using e-commerce. One of the reasons for such a situation is the fear of possible abuses or the fear that e-commerce is insecure. Therefore, in order to increase e-commerce in Serbia, one of the priorities should be work on increasing the security of participants in e-commerce to reduce the possible abuses. From the research a conclusion can be drawn that the level of education significantly affects the use of e-commerce in Serbia and that it should be constantly worked on raising the educational level of the citizens in order for them to be able to properly use the advantages that e-commerce offers

TESTING THE ATTITUDE TOWARD THE USE OF E-COMMERCE BASED ON THE CUSTOMER’S EDUCATIONAL LEVEL: THE CASE OF THE REPUBLIC OF SERBIA

The subject of this paper is to examine to what extent and in which way educational level influences the use of e-commerce in the Republic of Serbia, as well as, in part, to examine customer satisfaction with e-commerce. The main objective of this paper is to determine the level of customer use of e-commerce depending on their educational level, as well as to spot the areas which need to be improved in order to increase the degree of use of e-commerce in the Republic of Serbia. For the purposes of sorting and grouping the data in this study the statistical method has been used. All collected data were processed in the statistical software SPSS (descriptive and parametric analyses were used, as well as comparison of mean values, correlation and regression). Based on the results of the tests conducted it is to conclude that the respondents generally use e-commerce in Serbia on a small scale and that other technological advances are accepted to a greater extent than e-commerce. The respondents have very low confidence while using e-commerce. One of the reasons for such a situation is the fear of possible abuses or the fear that e-commerce is insecure. Therefore, in order to increase e-commerce in Serbia, one of the priorities should be work on increasing the security of participants in e-commerce to reduce the possible abuses. From the research a conclusion can be drawn that the level of education significantly affects the use of e-commerce in Serbia and that it should be constantly worked on raising the educational level of the citizens in order for them to be able to properly use the advantages that e-commerce offers

Prestige and national identity as predictors of food products purchase

In modern living conditions, consumers have access to a greater offer of food products than ever before. In addition to local food products, the growth of foreign food products is noticeable, which significantly intensifies competition in this sector. The paper analyzes whether and how national identity and prestige affect the assessment of local food products and whether this assessment affects readiness to buy them. The research objective is to show whether national identity influences the purchase of local food products among consumers in Serbia, and whether prestige is important for the purchase process, as is the case with other product categories. The main research results indicate that the prestige factor has an impact on the assessment of both local and foreign food products, while the national identity factor has an impact only on local food product assessment. Also, research results indicate that food product assessment has an impact on the purchase of both local and foreign food products

Two Stability Criteria for Benzenoid Hydrocarbons and Their Relation

A new, simple, relation is established between the total π-electron energy and the HOMO-LUMO gap, applicable to benzenoid hydrocarbons. This work is licensed under a Creative Commons Attribution 4.0 International License

Constructing NSSD molecular graphs

A graph is said to be non-singular if it has no eigenvalue equal to zero; otherwise it is singular. Molecular graphs that are non-singular and also have the property that all subgraphs of them obtained by deleting a single vertex are themselves singular, known as NSSD graphs, are of importance in the theory of molecular π-electron conductors; NSSD = non-singular graph with a singular deck. Whereas all non-singular bipartite graphs (therefore, the molecular graphs of all closed-shell alternant conjugated hydrocarbons) are NSSD, the non-bipartite case is much more complicated. Only a limited number of non-bipartite molecular graphs have the NSSD property. Several methods for constructing such molecular graphs are presented.peer-reviewe