bluuebunny/crossref_metadata_2025_split huggingface dataset:
Finite-time integral sliding mode control for chaotic permanent magnet synchronous motor systems
Authors: Chibani Abdelilah , Daaou Bachir , Gouichiche Abdelmadjid , Safa Ahmed , Messlem Youcef 
Published: June 2017

AbstractIn this paper, an integral finite-time sliding mode control scheme is presented for controlling a chaotic permanent magnet synchronous motor (PMSM). The controller can stabilize the system output tracking error to zero in a finite time. Using Lyapunov’s stability theory, the stability of the proposed scheme is verified. Numerical simulation results are presented to present the effectiveness of the proposed approach.
Research on the influence of driving harmonic on electromagnetic field and temperature field of permanent magnet synchronous motor
Authors: Qiu Hongbo , Yu Wenfei , Li Yonghui , Yang Cunxiang 
Published: June 2017

AbstractAt present, the drivers with different control methods are used in most of permanent magnet synchronous motors (PMSM). A current outputted by a driver contains a large number of harmonics that will cause the PMSM torque ripple, winding heating and rotor temperature rise too large and so on. In this paper, in order to determine the influence of the current harmonics on the motor performance, different harmonic currents were injected into the motor armature. Firstly, in order to study the influence of the current harmonic on the motor magnetic field, a novel decoupling method of the motor magnetic field was proposed. On this basis, the difference of harmonic content in an air gap magnetic field was studied, and the influence of a harmonic current on the air gap flux density was obtained. Secondly, by comparing the fluctuation of the motor torque in the fundamental and different harmonic currents, the influence of harmonic on a motor torque ripple was determined. Then, the influence of different current harmonics on the eddy current loss of the motor was compared and analyzed, and the influence of the drive harmonic on the eddy current loss was obtained. Finally, by using a finite element method (FEM), the motor temperature distribution with different harmonics was obtained.
Impact of inductor current ringing in DCM on output voltage of DC-DC buck power converters
Authors: Walczak Marcin 
Published: June 2017

AbstractRinging of an inductor current occurs in a DC-DC BUCK converter working in DCM when current falls to zero. The oscillations are the source of interferences and can have a significant influence on output voltage. This paper discusses the influence of the inductor current ringing on output voltage. It is proved through examples that the oscillations can change actual value of duty a cycle in a way that makes the output voltage difficult to predict.
Improvement of the finite element method equations conditioning for the magnetic field-circuital problems
Authors: Gołębiowski Marek 
Published: June 2017

AbstractThe presented systems with magnetically coupled windings are solved with the finite element method. If the issue of voltage supply is analyzed, a system of linear equations with a partially skew-symmetric sparse matrix is obtained. Iterative methods used to solve a system of equations are particularly effective for symmetric matrices. Resultant equations can be reduced to this symmetrical form by using the method known from the literature [1]. The ratio of the maximum to the minimum eigenvalue of the main matrix of this circuit, which is the condition number, is however very high. This means that the problem is ill-conditioned and leads to a very long iterative solution process. The method presented in the article allows for a direct solution of a system of equations on its part, corresponding to high eigenvalues of the system matrix. The remaining part of the system of equations is solved by iterative methods. This part has much better condition number, and therefore the computational process is fast. The proposed iterative process depends on multiplication of a sparse matrix by vectors. It is not necessary (and possible) to store the entire matrix. This is especially important for larger sizes of a matrix.
Surface Impedance Boundary Conditions applied to solving nonlinear electrodynamic systems
Authors: Pawłowski Stanisław , Plewako Jolanta 
Published: June 2017

AbstractThe paper presents a method for solving electromagnetic field problems by applying impedance boundary conditions for systems including conducting bodies of nonlinear magnetic properties in an excited harmonic field. Three types of impedance boundary conditions were derived. A procedure for computing surface impedance based on the transfer matrix is proposed. This procedure has been tested by comparing computational results to calculations where time function distortions were considered, and to the experimental data.
Gender Differences and Consumer Behavior of Millennials
Authors: Kraljević Radojka , Filipović Zrinka 
Published: June 2017

AbstractMillennial generation is considered the largest and best educated and therefore presents challenges to marketers. This paper aims to examine the gender differences in consumer behaviour of students - generation y. The study identifies gender differences in purchase behaviour, loyalty, price sensitivity and shopping habits. The empirical analysis is based on data obtained from a student survey (N=118; M=40, 68%, F=59, 32%). The data were analysed using chi-square test. Our findings suggest that women are more sensitive to price than men. They also belong more to the loyalty programs and use more loyalty awards schemes. Although the millennial generation has the reputation for being digital our study shows that they actually like visiting the stores instead of shopping online although the statistically significant difference is not found.
Managing Macroeconomic Risks by Using Statistical Simulation
Authors: Merkaš Zvonko , Perkov Davor , Miličević Petra 
Published: June 2017

AbstractThe paper analyzes the possibilities of using statistical simulation in the macroeconomic risks measurement. At the level of the whole world, macroeconomic risks are, due to the excessive imbalance, significantly increased. Using analytical statistical methods and Monte Carlo simulation, the authors interpret the collected data sets, compare and analyze them in order to mitigate potential risks. The empirical part of the study is a qualitative case study that uses statistical methods and Monte Carlo simulation for managing macroeconomic risks, which is the central theme of this work. Application of statistical simulation is necessary because the system, for which it is necessary to specify the model, is too complex for an analytical approach. The objective of the paper is to point out the previous need for consideration of significant macroeconomic risks, particularly in terms of the number of the unemployed in the society, the movement of gross domestic product and the country’s credit rating, and the use of data previously processed by statistical methods, through statistical simulation, to analyze the existing model of managing the macroeconomic risks and suggest elements for a management model development that will allow, with the lowest possible probability and consequences, the emergence of the recent macroeconomic risks. The stochastic characteristics of the system, defined by random variables as input values defined by probability distributions, require the performance of a large number of iterations on which to record the output of the model and calculate the mathematical expectations. The paper expounds the basic procedures and techniques of discrete statistical simulation applied to systems that can be characterized by a number of events which represent a set of circumstances that have caused a change in the system’s state and the possibility of its application in the field of assessment of macroeconomic risks. The method has no limitations. It can be used to study very complex systems by using special computer programs. The method uses reasonable estimates for important economic inputs to determine a set of results, not only one outcome at one point in time, yet there is a multiple-possibilities estimation of a certain risk performance, regarding the range of economic variables used in the model. Attempt to influence and influence itself on certain macroeconomic risks, in today’s economy, occupies one of the primary imperatives of the world, therefore, this paper deals with the mutual correlation and application of statistical simulations in macroeconomic risks measurement in order to better prevention and remediation.
Assessment and Comparison of Tourism Vocabulary Skills in ESL Learners
Authors: Pokupec Martina , Njerš Diana , Benić Hilarija Lozančić 
Published: June 2017

AbstractTeaching and learning English for professional purposes largely involves the acquisition of specialised vocabulary, with teaching methodology focusing on the development of understanding and usage of specific vocabulary items. Within the wide variety of professional purposes the language is acquired for, teaching learners of tourism and hospitality also requires a focus on a range of specific language skills, mostly based on understanding of diverse types of discourse and strong communication skills in varied language situations and contexts. English for professional purposes thus becomes more specific - English for Tourism and Hospitality - signalling a slightly different approach to teaching and learning, i.e. not heavily based on acquiring vocabulary skills, but shifting focus on strong communication skills and enhancement of the four elementary language skills: reading, writing, listening and speaking.This paper focuses on assessing and comparing receptive and productive vocabulary skills of learners of English as a Second Language (ESL), with a general hypothesis that learners with greater general language competences do not exhibit major problems in inferencing the meaning of specialised urban tourism vocabulary items.For this purpose, we selected 10 vocabulary items in context sentences and conducted the Vocabulary Knowledge Scale (VKS) test developed by Wesche and Paribakht (1996) with 1styears students of Tourism and Hospitality and students of Business Economics of the Libertas International University. The results obtained by descriptive statistics, Mann-Whitney U test and Spearman’s rank correlation confirm our general hypothesis.
In Tourism Industry We Talk About Sustainable Development, But We Evaluate Profits and Growth
Authors: Sirk Tanja 
Published: June 2017

Abstract
Tourism is one of the biggest economic sectors, it has a significant impact on the environment. At the same time, the long-term development of tourism also greatly depends on the environment it affects. Experts are unanimous that it is necessary for the longterm existence and development of tourism that it becomes sustainable. Nevertheless, in tourism businesses, sustainable development strategies are not sufficiently present and put into practice. The author of the article presents the argument as a possible reason for this: the management of tourism enterprises as well as management of all the companies is focused on doing business successfully; and because the performance of management is assessed in terms of growth and security of its operations, and not in relation to the measures taken in the field of sustainable development, management gives priority to ensuring relatively short-term growth and security of operations.
Challenges and Aspects of Cyber Security of the Republic of Croatia
Authors: Protrka Nikola , Marić Kristijan , Plećaš Mihael 
Published: June 2017

Abstract
The development of the information and communication technology (ICT), regardless of its many advantages, unfortunately has its disadvantage - the abuse of the cyberworld. The global character of cyberspace is specific in terms of national legislation and its view of specificities. Some countries adopted the recommendation of the Convention on Cybercrime of the Council of Europe (Official Gazette NN-MU 9/02, 4/04) and amended their national legislation, whereas others kept implementing their criminal law solutions, which are outdated and cannot reach the level of this type of criminal offences. Consequently, governments are inclined to cooperate and exchange information about this type of crime due to the fact that the criminal offender may be anywhere, and the offence itself can take place at a great distance from the offender. In September 2015, the government of the Republic of Croatia adopted the National Cyber Security Strategy and the Action Plan for the Implementation of the National Cyber Security Strategy, the first allencompassing strategy of the Republic of Croatia on cyber security. The paper also focuses on the role of the Police College in the Action Plan for the Implementation of the National Cyber Security Strategy.
Thermodynamic study of phase equilibrium of superionic alloys of Ag3SBr1−xClx system in the concentration range 0.0–0.4 and temperature range 370–395 K
Authors: Moroz M.V. , Prokhorenko M.V. , Prokhorenko S.V. , Reshetnyak O.V. 
Published: June 2017

Abstract
Thermodynamic assessment of the phase stability of the solid solutions of superionic alloys of the Ag3SBr1−xClx (I) system in the concentration range 0 ≤ x ≤ 0.4 and temperature range 370-395 K was performed. Partial functions of silver in the alloys of solid solution were used as the thermodynamic parameters. The values of partial thermodynamic functions were obtained with the use of the electromotive force method. Potential-forming processes were performed in electrochemical cells. Linear dependence of the electromotive force of cells on temperature was used to calculate the partial thermodynamic functions of silver in the alloys. The serpentine-like shape of the thermodynamic functions in the concentration range 0-4 is an evidence of the metastable state of solid solution. The equilibrium phase state of the alloys is predicted to feature the formation of the intermediate phase Ag3SBr0.76Cl0.24, and the solubility gap of the solid solution ranges of Ag3SBr0.76Cl0.24 and Ag3SBr.
Thermodynamic analysis of a new dual evaporator CO2 transcritical refrigeration cycle
Authors: Abdellaoui Ezzaalouni Yathreb , Kairouani Lakdar Kairouani 
Published: June 2017

AbstractIn this work, a new dual-evaporator CO2transcritical refrigeration cycle with two ejectors is proposed. In this new system, we proposed to recover the lost energy of condensation coming off the gas cooler and operate the refrigeration cycle ejector free and enhance the system performance and obtain dual-temperature refrigeration simultaneously. The effects of some key parameters on the thermodynamic performance of the modified cycle are theoretically investigated based on energetic and exergetic analysis. The simulation results for the modified cycle indicate more effective system performance improvement than the single ejector in the CO2vapor compression cycle using ejector as an expander ranging up to 46%. The exergetic analysis for this system is made. The performance characteristics of the proposed cycle show its promise in dual-evaporator refrigeration system.
Determination of dryout localization using a five-equation model of annular flow for boiling in minichannels
Authors: Wajs Jan , Mikielewicz Dariusz 
Published: June 2017

AbstractDetailed studies have suggested that the critical heat flux in the form of dryout in minichannels occurs when the combined effects of entrainment, deposition, and evaporation of the film make the film flow rate go gradually and smoothly to zero. Most approaches so far used the mass balance equation for the liquid film with appropriate formulations for the rate of deposition and entrainment respectively. It must be acknowledged that any discrepancy in determination of deposition and entrainment rates, together with cross-correlations between them, leads to the loss of accuracy of model predictions. Conservation equations relating the primary parameters are established for the liquid film and vapor core. The model consists of three mass balance equations, for liquid in the film as well as two-phase core and the gas phase itself. These equations are supplemented by the corresponding momentum equations for liquid in the film and the two-phase core. Applicability of the model has been tested on some experimental data.
Pollutant bioaccumulation in anchovy (Engraulis encrasicolus) tissue, fish species of commercial interest at the Romanian Black Sea coast
Authors: Galaţchi Mădălina , Oros Andra , Coatu Valentina , Costache Mioara , Coprean Dragomir , Galaţchi Liviu-Daniel 
Published: June 2017

Abstract
The pollution of the marine ecosystem is a world-wide problem. Heavy metals and organochlorine compounds are among the most harmful elemental pollutants and are of particular concern because of their toxicity to humans. Anchovy (Engraulis encrasicolus, Linnaeus 1758), small pelagic fish with a key ecological role in the marine food web, is an important link connecting the lower and upper trophic levels, being also a valuable species for human consumption. Thus, anchovy samples were collected from different stations along the Romanian Black Sea coast and the analyzed contaminants were organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and heavy metals (Cd, Pb, Ni, Cu and Cr) in muscle tissue. Cd and Pb are the heavy metals that exceeded the allowed levels under the EU legislation (0.3 μg/g), Cd recorded values within the range 0.29-0.51 μg/g (average 0.36 ± 0.09 μg/g) and Pb recorded values within the interval 0.29-1.62 μg/g (average 0.75 ± 0.57 μg/g). Regarding organochlorine pesticides, the highest level was recorded by p,p′-DDE (6.76±1.21 ng/g/dry weight), followed by p,p′-DDD (3.88±0.97 ng/g/dry weight). Among PCB’s, the highest level was recorded by PCB 28 (5.19±1.29 ng/g/dry weight). The results of this study revealed that heavy metals, pesticides and polychlorinated biphenyls values identified in anchovy tissue, species of commercial interest from the Black Sea, are not threatening to human consumers.
Evaluation of anticancer properties of a new α-methylene-δ-lactone DL-249 on two cancer cell lines
Authors: Pomorska Dorota K. , Gach-Janczak Katarzyna , Jakubowski Rafał , Janecki Tomasz , Szymański Jacek , Janecka Anna 
Published: June 2017

AbstractBackgroundThe anticancer activity of a new synthetic α-methylene-δ-lactone DL-249 was reported in leukemia HL-60 and breast cancer MCF-7 cells and compared with the activity of a natural α-methylene-γ-lactone from Tanacetum parthenium, parthenolide.MethodologyThe chemical synthesis of DL-249 was performed using Horner-Wadsworth-Emmons methodology. The cytotoxic activity of the tested compounds was assessed by an MTT test. The ability to induce apoptosis was studied by flow cytometry. The expression levels of genes were determined by quantitative real-time PCR.Principal Findings/ResultsDL-249 and parthenolide inhibited the growth of HL-60 and MCF-7 cells with IC50 values below 10 μM. DL-249 was a stronger apoptosis inducer than parthenolide in both cell lines and both compounds produced a more pronounced effect on HL-60 than on MCF-7 cells. DL-249 and PTL significantly up-regulated expression of Bax, caspase-9, caspase-3 and p53 genes and decreased the level of Bcl-2 and Bcl-xl genes in both cancer cell lines. Additionally DL-249 caused cell cycle arrest in the subG0/G1phase.Conclusion/SignificanceA new synthetic α-methylene-δ-lactone, DL-249 showed the anticancer activity on two cancer cell lines and seemed to be a better apoptosis inducer than parthenolide which makes this compound an attractive lead for further studies.
Evaluation of Vitamin D, Vitamin D Binding Protein Gene Polymorphism with Oxidant – Antioxidant Profiles in Chronic Obstructive Pulmonary Disease
Authors: Al-Azzawi Mahmood A. , Ghoneim Adel H. , Elmadbouh Ibrahim 
Published: June 2017

SummaryBackground: The aim was to evaluate the association of plasma 25-hydroxyvitamin D (25-OHD) and vitamin D binding protein (VDBP or Gc-globin) gene polymorphism with oxidant-antioxidant profiles in patients with chronic obstructive pulmonary disease (COPD), and their role as biomarker risk factors in susceptibility and severity of COPD. Methods: Eighty patients diagnosed with COPD (mild, moderate and severe according to lung function tests; FEV 1%) and 80 healthy controls were included in the study. Serum nitric oxide (NO) and lipid peroxide (LP), plasma reduced glutathione (RGSH), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) activity, 25-OHD and VDBP polymorphism were analyzed in all subjects. Results: COPD patients had significantly decreased serum NO, plasma SOD, RGSH, GSH-Px, CAT and 25-OHD versus controls, but had significantly increased serum LP. In COPD patients, 25-OHD levels were significantly lower (41.49± 13.65 ng/mL) versus controls, but more lower in severe COPD patients (30.54±9.09 ng/mL; sensitivity 79.2%; spe - cificity 73.2%, p<0.001) versus mild and moderate COPD. VDBP genotypes frequencies were Gc1S-1S=23.8%, Gc1F-1S=28.8%, Gc1F-1F=15%, Gc1S-2=20%, Gc1F-2=11.3% and Gc2-2=1.3%. Also, VDBP variants frequencies were Gc1S=48.1%, Gc1F=35% and Gc2=16.6%. How ever, Gc1F-1S genotypes and Gc1F variants were significantly higher than in controls (10%, 12.5%; p=0.009, p=0.001, respectively). Moreover, in severe COPD patients, Gc1F-1S genotype was significantly higher than in mild COPD (41.7% vs 31.3%, p=0.04). Conclusion: COPD patients had significantly lower plasma 25-OHD and were associated with significantly higher VDBP Gc1F-1S genotypes and Gc1F variants frequencies than controls. Low vitamin D levels and VDBP polymorphism may be important as diagnostic risk factors in the susceptibility to and severity of COPD.
Laboratory Medicine Management: Leadership Skills for Effective Laboratory
Authors: Majkić-Singh Nada 
Published: June 2017

SummaryForum of the European Societies of Clinical Chemistry (FESCC) decided that the FESCC Symposium for Balkan Region would be held each year in Belgrade and organized by the Society of Medical Biochemists of Serbia and Montenegro (SMBSM). Professor Victor Blaton, at the time President of the FESCC, supported the organization of the Symposium. Purpose of these Symposia has been to educate clinical biochemists from Balkan region to improve management, leadership skills for effective laboratories. As a result of these decision twelve symposia have been organized thus far very successfully. Here the most important Symposium topics will be reviewed. Also, the 13thEFLM Symposium for Balkan Region under the title »Laboratory Medicine Management: Leadership Skills for Effective Laboratory«(Belgrade, September 2017) is organized by EFLM and SMBS under the Auspices of the International Federation of Clinical Chemistry (IFCC), Ministry of Education, Science and Technological Development of Serbia and Ministry of Health of Serbia with participation of the European and domestic specialists in field of Laboratory Medicine.
The temporalized Massey’s method
Authors: Franceschet Massimo , Bozzo Enrico , Vidoni Paolo 
Published: June 2017

AbstractWe propose and throughly investigate a temporalized version of the popular Massey’s technique for rating actors in sport competitions. The method can be described as a dynamic temporal process in which team ratings are updated at every match according to their performance during the match and the strength of the opponent team. Using the Italian soccer dataset, we empirically show that the method has a good foresight prediction accuracy.
Positive solutions for Hadamard differential systems with fractional integral conditions on an unbounded domain
Authors: Jessada Tariboon , Ntouyas Sotiris K. , Asawasamrit Suphawat , Promsakon Chanon 
Published: June 2017

AbstractIn this paper, we investigate the existence of positive solutions for Hadamard type fractional differential system with coupled nonlocal fractional integral boundary conditions on an infinite domain. Our analysis relies on Guo-Krasnoselskii’s and Leggett-Williams fixed point theorems. The obtained results are well illustrated with the aid of examples.