bluuebunny/crossref_metadata_2025_split huggingface dataset:
Controllability of dynamical systems. A survey
Authors: Klamka J. 
Published: May 2018

Abstract
The main objective of this article is to review the major progress that has been made on controllability of dynamical systems over the past number of years. Controllability is one of the fundamental concepts in the mathematical control theory. This is a qualitative property of dynamical control systems and is of particular importance in control theory. A systematic study of controllability was started at the beginning of sixties in the last century, when the theory of controllability based on the description in the form of state space for both time-invariant and time-varying linear control systems was worked out.
Roughly speaking, controllability generally means, that it is possible to steer a dynamical control system from an arbitrary initial state to an arbitrary final state using the set of admissible controls. It should be mentioned, that in the literature there are many different definitions of controllability, which strongly depend on a class of dynamical control systems and on the other hand on the form of admissible controls.
Controllability problems for different types of dynamical systems require the application of numerous mathematical concepts and methods taken directly from differential geometry, functional analysis, topology, matrix analysis and theory of ordinary and partial differential equations and theory of difference equations. In the paper we use mainly state-space models of dynamical systems, which provide a robust and universal method for studying controllability of various classes of systems.
Controllability plays an essential role in the development of modern mathematical control theory. There are various important relationships between controllability, stability and stabilizability of linear both finite-dimensional and infinite-dimensional control systems. Controllability is also strongly related to the theory of realization and so called minimal realization and canonical forms for linear time-invariant control systems such as the Kalmam canonical form, the Jordan canonical form or the Luenberger canonical form. It should be mentioned, that for many dynamical systems there exists a formal duality between the concepts of controllability and observability. Moreover, controllability is strongly connected with the minimum energy control problem for many classes of linear finite dimensional, infinite dimensional dynamical systems, and delayed systems both deterministic and stochastic.
Finally, it is well known, that controllability concept has many important applications not only in control theory and systems theory, but also in such areas as industrial and chemical process control, reactor control, control of electric bulk power systems, aerospce engineering and recently in quantum systems theory.
Oilless and frictionless compressor with double-sided rotationally oscillating piston
Authors: Chomczyk W. , Ostapski W. , Piotrowski J. , Tataj T. 
Published: May 2018

Abstract
The contents are concerned with a concept of an oilless and frictionless compressor operating without dead movement and having functional parameters superior to compressors of renowned manufacturers. The concept is based on patents No. 68220, 83060, P377851 by W. Chomczyk and patents P394072, P385733 by W. Chomczyk, W. Ostapski and J. Piotrowski. The proposed design of an oilless compressor ensures volumetric efficiency higher than that encountered in conventional compressors. It also generates pure compressed medium without necessity of filtering from oil particles, which is especially desired in food, pharmaceutical, medical, fragrance, chemical and automation industry.
Comparison of experimental and modelling results of thermal properties in Cu-AlN composite materials
Authors: Chmielewski M. , Weglewski W. 
Published: May 2018

Abstract
Copper-based composites could be widely used in automotive, electronic or electrical industry due to their very promising thermal properties. In the present paper, Cu-AlN metal matrix composites with ceramic volume fractions between 0.1 and 0.4 were fabricated by hot pressing method in vacuum. Dependence of the coefficient of thermal expansion (CTE) and the thermal conductivity (TC) on the chemical composition of composites has been investigated. The measured values of the thermal expansion coefficient have been compared with the analytical models’ predictions. A numerical model based on FEAP 7.5 in 3D space has been used to evaluate the influence of the porosity on the thermal properties (thermal conductivity) of the composite. A fairly good correlation between the FEM results and the experimental measurements has been obtained.
Fatty Acid Profile of Milk - A Review
Authors: Markiewicz-Kęszycka Maria , Czyżak-Runowska Grażyna , Lipińska Paulina , Wójtowski Jacek 
Published: May 2018

Abstract
The article describes the recent data dealing with the fatty acid content in cow, goat, and sheep milk. A large body of evidence demonstrates that fatty acid profile in goat and sheep milk was similar to that of cow milk. Palmitic acid was the most abundant in milk. Goat milk had the highest C6:0, C8:0, and C10:0 content. Sheep milk was the richest source of conjugated linoleic acid and α-linolenic acid. Ewe’s milk had lower value of n-6/n-3 then goat and cow milk.
Effect of Storage and Preservation of Horse Faecal Samples on the Detectability and Viability of Strongylid Nematode Eggs and Larvae
Authors: Jagła Ewelina , Śpiewak Justyna , Zaleśny Grzegorz , Popiołek Marcin 
Published: May 2018

Abstract
The aim of the study was to assess selected methods of storage and preservation of horse faecal samples on the detectability of eggs and survival rate of larvae of strongylid nematodes. Physical and chemical factors were found to have a significant effect on the egg detectability and survival of the larvae. The comparison of control and variously preserved samples revealed that each storage method affected the reliability of the results to some extent. Short-lasting, three-day freezing resulted in a decrease of detectability from 100% to 94.1%, with an equally significant decrease in the mean number of eggs per one gram of faeces, from 1,238.97 to 983.82. Extending the freezing period from 3 to 14 d had a highly significant effect on the prevalence, which was then 85.3%, while the EPG (eggs per gram) value decreased more than twice, compared to control samples, and was 503.68. Thirty-day freezing had no further effect on the parasitological indices, which did not differ significantly from those obtained after a fortnight of freezing. Storing samples in 4% formalin and 40% ethanol had a significantly more negative effect on the detectability of strongylid eggs. The prevalence in alcohol-preserved samples was 91.2% and the EPG was 247.79; the values for formalin-preserved samples were 88.2% and 153.68. The way of preserving faecal samples was also found to affect the viability of strongylid larvae.
Typing of Listeria Monocytogenes Isolated from Slaughtered Cattle and Beef Meat
Authors: Dmowska Katarzyna , Wieczorek Kinga , Lynch Orla , Osek Jacek 
Published: May 2018

Abstract
A total of 135 L. monocytogenes strains isolated from slaughtered cattle and beef meat were tested by the pulsed field gel electrophoresis (PFGE). The AscI restriction analysis revealed a genetic heterogeneity among investigated isolates since 31, 9, and 35 profiles were distinguished among hide, carcass, and meat strains, respectively. The PFGE profiles of the isolates were also analysed in relation to serotypes, virulence genes, and antimicrobial resistance. It was shown that strains displaying the same PFGE type were of the same serotype while correlation between pulsotype and antimicrobial resistance was poor. The obtained results suggest that a cross-contamination between bovine hides and carcasses may occur during the slaughter process. Moreover, identification of identical PFGE types among L. monocytogenes found during a study period may suggest a common source of contamination or presence of persistent strains able to survive for a long time. These results emphasise the importance of molecular subtyping methods, including PFGE, in monitoring and tracking pathogen contamination along food chain.
Influence of Docosahexaenoic Acid Obtained from New Generation of Eggs on the Repolarisation of Ventricles in Pigs with Experimental Tachycardiomyopathy
Authors: Noszczyk-Nowak Agnieszka , Pasławska Urszula , Nicpoń Józef , Janiszewski Adrian , Skrzypczak Piotr , Popiel Jarosław , Bobak Łukasz , Trziszka Tadeusz 
Published: May 2018

Abstract
The influence of docosahexaenoic (DHA) acid obtained from a new generation of eggs on ventricular electrical function of 24 pigs with experimentally induced tachycardiomyopathy was described. Two groups were formed, 12 pigs had experimentally evoked tachycardiomyopathy and were getting standard feed (control group TIC). Twelve pigs with tachycardiomyopathy received feed with an addition of a dietary supplement containing phospholipids isolated from new generation of eggs at a dose of 1,000 mg of DHA/animal/24 h (experimental group TIC). Electrophysiological study was carried out from an external programmer immediately after implantation of the pacemaker. All the tests were carried out in general anaesthesia. After 8 weeks of fast ventricular pacing at 170 bpm in pigs receiving phospholipids obtained from eggs, a statistically significant shortening of ventricular refraction time was observed during sinus rhythm and also during the ventricular pacing of 130 bpm, and 150 bpm in the group of pigs fed standard feed. The ventricular refraction time in the sinus rhythm was significantly longer after 12 weeks of fast pacing and in the pacing at 130 bpm and 150 bpm it was significantly longer after 8 weeks of fast pacing. Phospholipids containing high percentage of n-3 polyunsaturated fatty acids (PUFA) obtained from new generation of eggs may contribute to the shortening ventricular refraction period after its oral administration. The n-3 PUFA obtained from a new generation of hen eggs may be an alternative to fish oil source of DHA and other polyunsaturated fatty acids.
An Efficient Algorithm for Steady State Analysis of Fibre Lasers Operating under Cascade Pumping Scheme
Authors: Sujecki Sławomir 
Published: May 2018

Abstract
We derive an efficient algorithm for the steady state analysis of fibre lasers operating under cascade pumping scheme by combining the shooting method with the Newton-Raphson method. We compare the proposed algorithm with the two standard algorithms that have been used so far in the available literature: the relaxation method and the coupled solution method. The results obtained show that the proposed shooting method based algorithm achieves much faster convergence rate at the expense of a moderate increase in the calculation time. It is found that a further improvement in the computational efficiency can be achieved by using few iterations of the relaxation method to calculate the initial guess for the proposed shooting method based algorithm
LCLS – Large Laser Infrastructure Development and Local Implications
Authors: Romaniuk Ryszard S. 
Published: May 2018

Abstract
The most powerful now in the world, American Xray laser LCLS (Linac Coherent Light Source), has been working as a research and user facility since 2009. It is further developed to LCLS II machine at the Stanford National Accelerator Laboratory SLAC in Menlo Park CA. In a certain sense, LCLS II is a response to the EXFEL machine and a logical extension of LCLS. All these machines are light sources of the fifth generation. EXFEL is expected to open user facility in 2016, at a cost of over 1 mld Euro. LCLS II, which design started in 2010, will be operational in 2017. The lasers LCLS, LCLS II and EXFEL use SASE and SEED methods to generate light and are powered by electron linacs, LCLS by a warm one, and EXFEL by a cold one. The linacs have energies approaching 20 GeV, and are around 2 - 3 km in length. EXFEL linac uses SRF TESLA microwave cavity technology at 1,3GHz. A prototype of EXFEL was FLASH laser. SLAC Laboratory uses effectively over 50 years experience in research, building and exploitation of linear electron accelerators. In 2009, a part of the largest 3 km SLAC linac was used to build the LCLS machine. For the LCLS II machine a new infrastructure is build for two new laser beams and a number of experimental stations. A number of experts and young researchers from Poland participate in the design, construction and research of the biggest world linear and elliptical accelerators and FEL lasers like LCLS (Stanford), EXFEL (DESY) and CEBAF (JLab), and a few more. The paper concentrates on the development state-of-the-art of large laser infrastructure and its global and local impact, in the competitive world of R&D. LCLS infrastructure implications in Poland are considered.
A –5 dBm 400MHz OOK Transmitter for Wireless Medical Application
Authors: Yousefi M. , Koozehkanani D. , Jangi H. , Nasirzadeh N. , Sobhi J. 
Published: May 2018

Abstract
A 400 MHz high efficiency transmitter for wireless medical application is presented in this paper. Transmitter architecture with high-energy efficiencies is proposed to achieve high data rate with low power consumption. In the on-off keying transmitters, the oscillator and power amplifier are turned off when the transmitter sends 0 data. The proposed class-e power amplifier has high efficiency for low level output power. The proposed on-off keying transmitter consumes 1.52 mw at -5 dBm output by 40 Mbps data rate and energy consumption 38 pJ/bit. The proposed transmitter has been designed in 0.18μm CMOS technology.
Predicting Dropout Student: An Application of Data Mining Methods in an Online Education Program
Authors: Yukselturk Erman , Ozekes Serhat , Türel Yalın Kılıç 
Published: May 2018

Abstract
This study examined the prediction of dropouts through data mining approaches in an online program. The subject of the study was selected from a total of 189 students who registered to the online Information Technologies Certificate Program in 2007-2009. The data was collected through online questionnaires (Demographic Survey, Online Technologies Self-Efficacy Scale, Readiness for Online Learning Questionnaire, Locus of Control Scale, and Prior Knowledge Questionnaire). The collected data included 10 variables, which were gender, age, educational level, previous online experience, occupation, self efficacy, readiness, prior knowledge, locus of control, and the dropout status as the class label (dropout/not). In order to classify dropout students, four data mining approaches were applied based on k-Nearest Neighbour (k-NN), Decision Tree (DT), Naive Bayes (NB) and Neural Network (NN). These methods were trained and tested using 10-fold cross validation. The detection sensitivities of 3-NN, DT, NN and NB classifiers were 87%, 79.7%, 76.8% and 73.9% respectively. Also, using Genetic Algorithm (GA) based feature selection method, online technologies self-efficacy, online learning readiness, and previous online experience were found as the most important factors in predicting the dropouts.
The Temporal Perspective in Higher Education Learners: Comparisons between Online and Onsite Learning
Authors: Romero Margarida , Usart Mireia 
Published: May 2018

Abstract
Higher Education increases flexibility with online learning solutions. Nevertheless, dropout rates in online university are large. Among the reasons, one aspect deserving further study is students’ Time Perspective (TP), which has been studied in onsite HE. It is necessary to know the TP profile of the growing population of online students, and consider its relation with students’ preference and convenience factors for choosing online or onsite contexts. In this study, learners’ TP in an online and an onsite Catalan HE institutions are compared. Results show that HE students present a high future orientation in general, while online students showed a higher orientation to past negativism. Basic guides are given to help institutions and students in the choice of the better suited learning context according to their TP.
Knowledge and Creativity in Digital Society
Authors: Fragnito Riccardo , Annarumma Maria 
Published: May 2018

Abstract
This work deals with the topic of creativity understood as a complex path carried out along all lifetime and that cannot be attributable to the mere accumulation of concepts. The changing social scenario promotes the dimension of the possible, the nonlinearity, the overcoming of preestablished trajectories of knowledge by triggering processes of meta-knowledge and metarepresentation, a dimension in which the creative mind finds a breeding ground.
The work explores the relationship between technology and creativity in consideration of the peculiar segment, the artistic one, where with greater evidence the work of the creative is unfolded.
A system-theory-based model for monthly river runoff forecasting: model calibration and optimization
Authors: Wu Jianhua , Qian Hui , Li Peiyue , Song Yanxun 
Published: May 2018

Abstract
River runoff is not only a crucial part of the global water cycle, but it is also an important source for hydropower and an essential element of water balance. This study presents a system-theory-based model for river runoff forecasting taking the Hailiutu River as a case study. The forecasting model, designed for the Hailiutu watershed, was calibrated and verified by long-term precipitation observation data and groundwater exploitation data from the study area. Additionally, frequency analysis, taken as an optimization technique, was applied to improve prediction accuracy. Following model optimization, the overall relative prediction errors are below 10%. The system-theory-based prediction model is applicable to river runoff forecasting, and following optimization by frequency analysis, the prediction error is acceptable.
The production of present and absent presences in education
Authors: Frelin Anneli , Grannäs Jan 
Published: May 2018

Abstract
Drawing on the distinction between absent and present presences, this article contributes to our understanding of how new managerial and performative discourses are played out in a secondary school context in Sweden. The consequences of numerous educational reforms during the last 20 years include a surge of new independent schools and increased segregation between students due to individual school choice. Following international trends, a yearly national municipal school ranking is published, drawing much attention both in the media and on the policy level, intensifying pressure for results at the municipal level. A case study was conducted in one bottom-ranked Swedish secondary school over the 2012-13 school year, focusing on how relationships between students and staff were negotiated in informal spaces and places. The results illustrate how absent presences and present presences are produced in the practice of schooling. The present presences were publication of results, raising merit scores and grading pressure, and the absent presences were the role of the media in the self-image of schools, increased workload for teachers, the misuse of statistical data and demoralization and determination. The results contribute to the understanding of a) the challenges that teachers and schools are faced with as a consequence of the new managerial and performative discourses in educational settings, and b) the means they draw on to face and resist them in their everyday practices.
Perspectives on English teacher development in rural primary schools in China
Authors: Ping Wang 
Published: May 2018

Abstract
Questionnaires are used to examine Chinese rural primary school English teachers’ needs and challenges and perceptions in the implementation of Standards for Teachers of English in Primary Schools as professional development in rural school contexts in China. A total of 300 teachers participated in the research. Their feedback illustrates that there are serious problems with the current training model and that teachers have a very high expectation of being involved in the Professional Graduate Certificate in Education.
Impact of Body Composition, Measured by Computed Tomography Scan, on Acute Pancreatitis Course
Authors: Ozola-Zālīte Imanta , Vīksna Anda , Ivanova Jeļena , Ūdre Agnese , Puķītis Aldis 
Published: May 2018

Abstract
Severe acute pancreatitis occurs in 15–25% of all patients with acute pancreatitis (AP), and has a dismal prognosis. Recognition of severe AP risk factors could provide identification and resuscitation of patients with impending severe course of disease. Our study aim was to analyse body composition, measured by computed tomography (CT) scans, in acute pancreatitis patients and its impact on disease severity. The study was a prospective cohort study carried out in the period from January 2015 – April 2016. In total 100 patients underwent CT imaging. Body constitution was analysed by CT examinations using the ImageJ v1.49q standard software. The third lumbar vertebra was selected as the landmark measurement. Muscular, visceral, subcutaneous, and intramuscular adipose tissue area were measured. Values were normalised for stature to obtain lumbar skeletal muscle and adipose tissue indexes (cm2/m2). Acute pancreatitis severity was determined by Atlanta revised criteria (2012). Among the included patients, moderately severe AP occurred in 83% (83 patients) cases, and severe AP in 17% (17 patients). 38% of the patients had normal weight according to BMI, 33% were overweight 33%, and 28% were obese. Sarcopenia was detected in 51%. Sarcopenia was found in six patients (35%) with severe AP and in 45 patients (54%) with moderately severe AP. General linear model analysis showed that obesity (p value = 0.026) and increased intramuscular fat area (p value = 0.029) had effect on severe AP. In conclusion, body composition analysis showed that adiposity is a risk factor for severe AP, and higher intramuscular fat area seemed to be another risk factor for severe AP.
Phenolics Content in Buckwheat Flour
Authors: Beitāne Ilze , Krūmiņa-Zemture Gita , Krūma Zanda , Cinkmanis Ingmārs 
Published: May 2018

Abstract
The objective of the current study was to analyse the total phenolic concentration (TPC), total flavonoid concentration (TFC), individual phenolic compound concentration and DPPH′ radical scavenging activity of four buckwheat (raw, roasted, white and dark) flour samples obtained from the Latvian market, in comparison to those of wheat flour, which is the most common ingredient in production of cereal products. TPC, TFC, and DPPH′ radical scavenging activity values were determined using spectrophotometric methods. Phenolic compounds were determined based on the high performance liquid chromatographic method (HPLC). All buckwheat flour samples had significantly higher TPC and TFC than wheat flour. The highest TPC (974.74 mg GAE·100 g−1 DW) and TFC (495.31 mg CE·100 g−1 DW) was found in raw buckwheat flour (p < 0.05). Buckwheat flour samples demonstrated similar DPPH′ radical scavenging activity, which ranged from 21.067 to 22.644 mM TE·100 g−1 dry matter, and was significantly higher (p < 0.05) than in wheat flour (0.731 mM TE·100 g−1 of dry matter). Dark buckwheat flour contained the highest level of rutin (4.613 mg·100 g−1), whereas raw buckwheat flour displayed the highest level of 3.5-dihydroxybenzoic acid (6.356 mg·100 g−1), sinapic acid (0.947 mg·100 g−1) and epicatechin (2.608 mg·100 g−1).