bluuebunny/crossref_metadata_2025_split huggingface dataset:
A novel hysteresis power point optimizer for distributed solar power generation
Authors: Veligorskyi Oleksandr , Husev Oleksandr , Shevchenko Viktor , Tytelmaier Kostiantyn , Yershov Roman , Kosenko Roman , Vinnikov Dmitri 
Published: August 2018

Abstract
This paper proposes a new photovoltaic panel maximum-power-point optimizer based on a buck converter. It can be connected to the DC-link distributed energy harvesting system that should perform the true maximum-power-point tracking algorithm based on maintaining a constant DC link voltage. The algorithm is based on the sensorless hysteresis control and ensures high efficiency. Three different realizations of proposed hysteresis optimizers have been analyzed in the paper, including operation principle and adjustment of hysteresis intervals. An experimental study has been performed for a portable low-power photovoltaic system in case of different loads and irradiance levels. The efficiency of maximum power point tracking has been calculated analytically for different hysteresis intervals and validated by experiment, which proved a 97-98 % efficiency of tracking for different PV panel temperatures. The proposed solution is recommended to be used in small- and medium-sized power systems where the price of the conventional maximum power point tracking converter is very high and is comparable to the cost of the individual panel
Considerations regarding the concept of cost-effective power-assist wheelchair subsystems
Authors: Galkin Ilya , Podgornovs Andrejs , Blinov Andrei , Vitols Kristaps , Vorobyov Maxim , Kosenko Roman 
Published: August 2018

Abstract
The present paper deals with the concept of a cost-effective power-assistant wheelchair. An analysis of the market situation and recent technical achievements is done at the beginning. On its basis, a set of solutions suitable for the development of such wheelchairs has been composed. It is shown that the key features of the considered concept are: segmented electrical motor and drive, sectioned battery pack, modular charger and an ANN matrix that provides easy and intuitive interfacing of sensor networks, pseudo-bionic feedbacks and the decision-making unit. Within the scope of the paper, a 3D model has been developed and 3D modelling has been conducted. As a result, certain drawbacks in the design and placement of elements have been found and a modification of the concept has been proposed
The Relationship Between Quality of Student Contribution in Learning Activities and their Overall Performances in an Online Course
Authors: Banoor Rajabalee Yousra , Rennie Frank , Santally Mohammad Issack 
Published: August 2018

Abstract
In this research we studied the correlation between the level of students’ online participation and their overall performances. We examined in this study, the participation level in different learning activities assigned to two large cohorts of learners, and compared them with their final grades at the end of the year. We defined the quality of their participation in the online course as being classified into the level of learning activities in which they participated. Learning activities were grouped into four levels which were identified namely at the knowledge, understanding, critical thinking skills and practical competencies. The findings revealed that participation in higher-order online learning activities, that is the higher ability to show critical skills and practical competencies, resulted in better grades of the learners in the module. However, the results also highlighted that overall students had a tendency to score more marks in the knowledge category as the activities required lower order cognitive skills. It was further observed that low performers demonstrated a tendency to obtain lower marks in all the four grouping levels and vice-versa for high performers. Two key elements can be concluded from the findings. The first aspect is about instructional design of such online courses where there is a need for the inclusion of learning activities targeted at the development of different types of skills, and second is the distribution and weighting given to these categories. The recommendation is that for first year students, a greater weighting of marks toward knowledge level activities will generally encourage good performances, and this could be gradually reviewed when they move on to level 2 onwards in their studies.
Kleene Algebra of Partial Predicates
Authors: Korniłowicz Artur , Ivanov Ievgen , Nikitchenko Mykola 
Published: August 2018

Summary
We show that the set of all partial predicates over a set D together with the disjunction, conjunction, and negation operations, defined in accordance with the truth tables of S.C. Kleene’s strong logic of indeterminacy [17], forms a Kleene algebra. A Kleene algebra is a De Morgan algebra [3] (also called quasi-Boolean algebra) which satisfies the condition x ∧¬:x ⩽ y ∨¬ :y (sometimes called the normality axiom). We use the formalization of De Morgan algebras from [8].
The term “Kleene algebra” was introduced by A. Monteiro and D. Brignole in [3]. A similar notion of a “normal i-lattice” had been previously studied by J.A. Kalman [16]. More details about the origin of this notion and its relation to other notions can be found in [24, 4, 1, 2]. It should be noted that there is a different widely known class of algebras, also called Kleene algebras [22, 6], which generalize the algebra of regular expressions, however, the term “Kleene algebra” used in this paper does not refer to them.
Algebras of partial predicates naturally arise in computability theory in the study on partial recursive predicates. They were studied in connection with non-classical logics [17, 5, 18, 32, 29, 30]. A partial predicate also corresponds to the notion of a partial set [26] on a given domain, which represents a (partial) property which for any given element of this domain may hold, not hold, or neither hold nor not hold. The field of all partial sets on a given domain is an algebra with generalized operations of union, intersection, complement, and three constants (0, 1, n which is the fixed point of complement) which can be generalized to an equational class of algebras called DMF-algebras (De Morgan algebras with a single fixed point of involution) [25]. In [27] partial sets and DMF-algebras were considered as a basis for unification of set-theoretic and linguistic approaches to probability.
Partial predicates over classes of mathematical models of data were used for formalizing semantics of computer programs in the composition-nominative approach to program formalization [31, 28, 33, 15], for formalizing extensions of the Floyd-Hoare logic [7, 9] which allow reasoning about properties of programs in the case of partial pre- and postconditions [23, 20, 19, 21], for formalizing dynamical models with partial behaviors in the context of the mathematical systems theory [11, 13, 14, 12, 10].
Survival and germinability of Rhynchosporium secalis conidia exposed to solar radiation
Authors: Al-Shehadah E. , Al-Daoude A. , Jawhar M. 
Published: August 2018

Abstract
Rhynchosporium secalis, the causal agent of barley scald disease, is a fungus commonly found in the environment. Disease spread within a field and between fields occurs through the aerial dispersal of the fungal spores. However, not much is known about the survival potential of fungal conidia exposed to solar radiation. In the present study, detached conidia of R. secalis were exposed simultaneously in the field to direct sunlight or placed in an adjacent ventilated enclosure in the dark for periods ranging from 0.5 to 8h. In addition, conidia were either exposed or not exposed to UV-C light (254 nm) for periods ranging between 0.5 and 60 min in the laboratory. After exposure, conidia were placed on water agar Petri dishes and allowed to germinate for 24h. Germinability of conidia was reduced by up to 94% after 8h of exposure to solar irradiance (670-860 Wm-2) in the field in comparison to the non-exposed control. Germinability of conidia in the laboratory was reduced up to ~100% by doses of UV-C light of 3.2±0.7 Wm-2. The results of this study will contribute to a better understanding of the relationship between climatic conditions and barley scald epidemics
Lethal and sublethal effects of ten insecticides, used in date palm production in Saudi Arabia, on the parasitoid Trichogramma cacoeciae
Authors: Hajjar M. Jamal , Al-Masoud M. 
Published: August 2018

Abstract
Lethal and sublethal effects of ten insecticides commonly used in date palm production in Saudi Arabia were assessed in the laboratory against adults of Trichogramma cacoeciae, an important egg parasitoid of the dried fruit moth Ephestia calidella. Bioassays were conducted according to the standard protocol of the International Organization for Biological Control IOBC/WPRS/Working Group ‘Pesticides and Beneficial Organisms’. Our results showed that cypermethrin, deltamethrin, malathion, phenthoate, methomyl, and carbosulfan were moderately harmful (IOBC Class 3) to the parasitoid. The botanical insecticides azadirachtin and matrine were moderately harmful (IOBC Class 3) and slightly harmful (IOBC Class 2), respectively. The insect growth regulator pyriproxyfen was slightly harmful, whereas bistrifluron was harmless (IOBC Class 1). Regarding sublethal effects, the parasitism ratios compared to control were reduced by pyriproxyfen and azadirachtin to 49.0% and 58.0%, respectively; hence they are classified as slightly harmful insecticides (IOBC Class 2). Bistrifluron and matrine were harmless (IOBC Class 1) as parasitism ratios were reduced by 9.2% and 27.6%, respectively. Longevity of adults exposed to bistrifluron and matrine (3.6 and 3.3 days, respectively) and to pyriproxyfen and azadirachtin (1.7 and 1.3 days, respectively) was significantly lower than that in control (4.67 days). In semi-field tests, residues of most insecticides on leaves of tomato, a common host plant of lepidopteran pests parasitized by T. cacoeciae, were considered moderately harmful to harmful based on parasitoid mortality at 24 h post-treatment whereas they were slightly harmful at 7 and 14 days post-treatment
Using Several Types of Virtual Characters in Sports - a Literature Survey
Authors: Petri K. , Bandow N , Witte K 
Published: August 2018

Abstract
This article discusses the development and application of virtual environments (VEs) in the domain of exercise as well as research in recreational and high-performance sports. A special focus is put on the use of virtual characters (VCs). For its elaboration, the following criteria parameters were chosen: scene content and the role of the VC, output device, kind of additional feedback, level of expertise of the tested participants, kind of user’s movement (reaction), kind of the visualization of the user’s body, kind of study and kind of evaluation. We explored the role of VCs embodying virtual opponents, teammates, or coaches in sports. We divided these VCs in passive and autonomous characters. Passive VCs are not affected by the user, whereas autonomous VCs adapt autonomously to the user’s movements and positions. We identified 44 sport related VEs, thereof 22 each in the domain of recreational sports and high-performance sports: of the identified 44 VEs, 19 VEs are without VC, 20 VEs with passive VCs, and 5 VEs with autonomous VCs. We categorized studies examining expert athletes in high-performance sports as well as studies analyzing novices, beginners or advanced athletes in recreational sports. Nevertheless, all identified systems are suitable for athletes of recreational and high-performance level
On run-length limited error control codes constructed from binary product codes
Authors: Farkaš Peter , Janvars Tomáš , Farkašová Katarína , Ružický Eugen 
Published: August 2018

Abstract
In this paper it is presented that run-length limited error control codes could be constructed from any two or more- dimensional binary product codes as long as at least one of the one-dimensional binary component codes is or can be converted to a run-length limited error control code. The advantages of this construction are as follows: It does not require any additional redundancy except that which is already contained in the original error control code and that the encoding and decoding procedure used for the underlying error control code do not to be changed
A note on ”a note on the magnetic vector potential”
Authors: Šumichrast L’ubomír , Dosoudil Rastislav 
Published: August 2018

Abstract
In the recently published short paper author deals with the derivation of the scalar potential pertaining to the point charge as well as of the vector potential pertaining to the point current. He shows his alternative approach and compares it to the ”traditional” methods commonly used in textbooks. Here we want to show that use of the generalised functions (symbolic functions, distributions) in the domain of electromagnetic field theory provides more straightforward and more rigorous approach to the problem.
The Troubled Pasts of Hungarian and German Minorities in Slovakia and Their Representation in Museums
Authors: Juhászová Tereza 
Published: August 2018

Abstract
In the 20th century, the two world wars reshaped the map of Central Europe as well as the status of Central Europe’s diverse societies. In my article, I focus on the Hungarian and German minorities in Slovakia and the representation of their problematic historical past in contemporary Slovak museums. More specifically, I zoom in on the exhibition Exchanged Homes displayed in Bratislava, which aims to commemorate the fate of Hungarians, Germans, and Slovaks, all of whom were affected by the population transfers after World War II. Based on the concept of memorial museums theorized by Paul Williams, I aim to show how the different exhibitions engage with the traumatic past of forceful resettlement. By offering multifaceted memories of a troubled past, these exhibitions avoid categorizing “victims” and “perpetrators” along national or ethnic lines. My paper thus analyzes the concepts and components of the exhibitions—the context of the postwar events, oral history interviews, and objects of everyday use that should bring the visitor closer to the experience of the people who were forced to leave. I argue that exhibitions of this sort have the ability to challenge the dominant historical narrative focusing on a national “Slovak” history and help the process of reconciliation between the Slovak majority society, and the Hungarian and German minorities.
US–Kenya Economic Relations under Obama and Their Image in the Kenyan News Discourse
Authors: Řehák Vilém 
Published: August 2018

Abstract
Economic cooperation between the US and Kenya has reflected the ups and downs in the relations between the two countries. Since independence, both countries have converged on security issues and diverged on questions of democracy and human rights. When Barack Obama was elected as the President of the US, Kenya expected to get an “Obama bonus” in the form of closer trade and investment cooperation. This article analyzes what is the image of US–Kenya economic relations in the news discourse. The analysis reveals that three different and competing narratives are present in the news discourse in Kenya. The US disseminates a narrative that economy, security, good governance and human resources are four interconnected and mutually reinforcing pillars of African development; Kenya must make progress in all these four pillars, and the US is ready to help Kenya. Kenyan leaders seem to internalize the economic part of the narrative and accept the nexus between economy and security, but they reject the nexus between economy and political issues. Finally, the Kenyan society internalizes both these narratives, albeit to a different degree, with the latter prevailing over the former. However, it also produces its own narrative, which presents current US–Kenya economic relations in a different perspective. The whole US engagement in Kenya hardly goes beyond the symbolical level. It is driven by US economic interests and competition with China, while there is no “Obama bonus” for Kenya.
Spatial perspectives on babies’ ways of belonging in infant early childhood education and care
Authors: Sumsion Jennifer , Harrison Linda J. , Stapleton Matthew 
Published: August 2018

Abstract
In this article, we endeavour to think spatially about the texture of infants’ everyday lives and their ways of ‘doing’ belonging in the babies’ room in an Australian early childhood education and care centre. Drawing on data from a large, multiple case-study project, and on theorisations of space that reject Euclidean notions of space as empty, transparent, relatively inert containers into which people, objects practices and artefacts are inserted, and instead emphasise space as complex, dynamic and relational, we map the navigating movements (Massumi, 2002) of baby Nadia. Through the telling of ‘stories-so-far’ (Massey, 2005), we convey how Nadia, as part of a constellation or assemblage of human and non-human beings, found ways to intensify space and to mobilise new vantage points, thus expanding the spatial possibilities of what we initially took to be a particularly confined and confining space.
Approaching the complex spatialities of early childhood education and care systems from the position of the child
Authors: Bollig Sabine 
Published: August 2018

Abstract
This paper proposes a way to understand what early care and education systems look like from the vantage point of the child. In other words, it aims to fuse a system perspective and a child perspective of early childhood education and care (ECEC) in a way that acknowledges children as active co-producers of ECEC landscapes. In developing this approach, I emphasize that children’s individual education and care arrangements which combine certain ECEC settings and the family are to be understood as networks of relations. As such, these child, family and ECEC relations create particular spatialities and temporalities which in turn position children very differently within the field of early education and care. To conceptualize how this takes place in children’s everyday activities, I refer to Schatzki’s and Massey’s relational thinking about practices, spaces, time and multiple identities with special emphasis on the spatial relations that are ‘beyond’ certain localities and (re)produced in the ‘events of place’. How this helps to understand the ways in which ECEC systems look from the position of the child will get exemplified in regard to Luxembourg’s complex ‘double split system’ of ECEC and its complex language terrain.
Shielding of metals from the corrosion induced by water and humidity by using scratch resistant and hydrophobic silica coatings
Authors: Shedam M. R. , Patil S. S. , Shedam Rakesh M. , Mathad Shridhar N. 
Published: August 2018

Abstract
The objective of the present paper is to demonstrate the effect of sol-gel derived scratch resistant coatings on different metal surfaces for anticorrosive applications. However, practical applications are limited by problems intrinsic to sol-gel processing or specific of coating/metal systems. Coatings aimed to improve oxidation and wet corrosion resistance have been studied the most. The results published in the literature show that sol-gel coatings may offer good protection against oxidation. More difficult is to achieve a protection against wet corrosion. An important aspect of the application of the sol-gel method for coating metallic objects is also the deposition technique.
The Еffect of Season and Parity on the Reproductive Performance of Sows
Authors: Dimitrov Stanimir , Karapetkovska-Hristova Vesna , Kochoski Ljupce , Trajkovska Biljana , Makarijoski Borche , Prodanovska-Poposka Vesna , Ntsomboh-Ntsefong Godswill 
Published: August 2018

Abstract
The aim of this study was to analyze the effect of season and number of parity on the reproductive performance of sows kept on a commercial farm. To achieve this objective, 800 nrs productive parent sows and a total of 958 parities were analyzed. The results show that sow’s breeding season had a significant effect on the weaning-to-oestrus interval, the farrowing rate, the litter size and weaning piglets with positive results during autumn, winter and spring seasons. The number of parity has a significant effect on the weaning-to-oestrus interval, litter size and weaning piglets with acceptable values in sows with more farrowing. The results of this study on a pig farm with analysis which highlights the risk factors associated with reproductive performance of sows, could be used to improve sow farm practices.
Non Wi-Fi Devices Interference Testing in a 2.4 GHz Wi-Fi Home
Authors: Sârbu Annamaria , Sârbu Marius , Șumălan Cosmin 
Published: August 2018

Abstract
Operating in probably the most crowded radio frequency bandwidth, the 2.4 GHz Wi-Fi is still common in the majority of living environments. Besides having to face problems regarding co-channel and adjacent channel influence, Wi-Fi often coexists with other radio technologies operating in this bandwidth which makes it ideal for interference testing.
In this article authors propose the use of freely available mobile applications to measure Wi-Fi signal spreading within a residential home as well as to quantify Wi-Fi performance in the presence of some commonly available interferers. A complete analysis of spectrum use is also provided by using a spectrum analyzer. We have found that Wi-Fi throughput degradation due to Bluetooth technology operated in the immediate vicinity of a mobile client is on average 26,5 % and decreases with distance from the Wi-Fi client. The presence of an active video baby monitor leads to a 7,5 % throughput degradation, but its functionality in heavy Wi-Fi traffic environment is however limited. The use of spectrograms in interference analysis is essential for a better understanding of the measured results.
Breast size impact on adjuvant radiotherapy adverse effects and dose parameters in treatment planning
Authors: Ratosa Ivica , Jenko Aljasa , Oblak Irena 
Published: August 2018

Abstract

Background
Breast radiotherapy is an established adjuvant treatment after breast conserving surgery. One of the important individual factors affecting the final cosmetic outcome after radiation is breast size. The purpose of this review is to summarise the clinical toxicity profile of adjuvant radiotherapy in women with breasts of various sizes, and to evaluate the treatment planning studies comparing target coverage and dose to thoracic organs at risk in relation to breast size.

Conclusions
Inhomogeneity and excessive radiation dose (hot spots) in the planning of target volume as well as large volume of the breast per se, all contribute to a higher rate of acute adverse events and suboptimal final cosmetic outcome in adjuvant breast cancer radiotherapy, regardless of the fractionation schedule. Improved homogeneity leads to a lower rate of ≥ grade 2 toxicity and can be achieved with three-dimensional conformal or modulated radiotherapy techniques. There may be an association between body habitus (higher body mass index, bigger breast size, pendulous breast, and large chest wall separation) and a higher mean dose to the ipsilateral lung and whole heart. A combination of the technical innovations (i.e. the breath-hold technique, prone position with or without holding breath, lateral decubitus position, and thermoplastic bra), dose prescription (i.e. moderate hypofractionation), and irradiated volume (i.e. partial breast irradiation) should be tailored to every single patient in clinical practice to mitigate the risk of radiation adverse effects.