University Of Siegen Research Articles

Wind Data Analysis, Annual Resource Estimation And Comparison With Measured Annual Energy Yield at the University Wind Turbine

Evaluation of the power potential of a particular type of wind turbine at a specific site is necessary for economic decisions. Therefore, the information of a wind turbine and that of a site have to be measured or predicted and then combined with the power curve of a wind turbine. The main objective of this research was to predict the power potential of the existing small wind turbine with a diameter of 3m and the wind turbine site at the University of Siegen and compare with the annual energy calculated from the measured one year of wind and turbine data. Techniques for prediction of the wind speed distribution of a site were determined and modeled. The power curve of the wind turbine was modeled from data recorded by applying a technique from the novel methods for modelling the power curve. In this research, artificial neural network, Weibull and Rayleigh are the techniques modeled to predict wind speed distribution at the wind turbine site. Rayleigh and Weibull were chosen since the two models depict a better wind speed distribution and require the mean and the standard deviation of the wind speed at the wind turbine site. A neural network trained with the backward propagation levernberg-Marquardt algorithm was applied to predict the wind speed and power potential of the wind turbine site. A comparison between Weibull, Rayleigh and the Levernberg-Marquardt trained neural network wind speed was made. The power curve of the wind turbine was successfully evaluated from wind data and wind turbine data recorded. The results indicate that the annual mean wind speed of the region is 2.54 (m/s) and about 20% of the wind availability was blowing from the west. The annual energy yield predicted from the trained neural network was 372 (kWh) closer to that determined from measured wind speed 360 (kWh) than that determined from Weibull and Rayleigh 337 and 233 (kWh) respectively. The three prediction models are applicable in any region to predict the annual energy of a particular wind turbine site with minimal data available.

Student Skills and Employability: A Study from Students’ Perspective

Student Skills and Employability: A Study from Students’ Perspective

European Solidarity at a Crossroads? Citizens’ Attitudes and Political Behaviors in Europe

Many observers have voiced their concerns that solidarity is at risk in Europe. Given this wider context, we are urgently in need of sound empirical analyses examining the various dimensions of solidarity in Europe. Public debates focus on solidarity in many respects but there is to date a lack of empirical evidence to draw upon to inform them. In this context, this special issue emerges from research conducted in the European Union–funded research project TransSOL devoted to the study of European solidarity (“European Paths to Transnational Solidarity in Times of Crisis”) running from 2015 to 2018. The project received funding under the Horizon 2020 program (Grant Agreement No. 649435). Christian Lahusen at the University of Siegen coordinated the overall project and Maria Grasso at the University of Sheffield coordinated the population survey for the project. The TransSOL survey includes approximately 2,000 respondents from each of the eight countries of the project (total N ~ 16,000): Denmark, France, Germany, Greece, Italy, Poland, Switzerland, and the United Kingdom. In the context of the project, the aim of the cross-national survey was to build a comparative dataset that would allow us to answer our theoretically relevant questions of interest on European solidarity such as those discussed in this introduction and in the other articles of this special issue. The articles in this special issue all analyze the data from this original survey dataset to shed systematic light into key theoretically-driven research questions on various aspects of European solidarity.

Canon Constitution and Canon Change in Children's Literature ed. by Bettina Kümmerling-Meibauer and Anja Müller

Reviewed by: Canon Constitution and Canon Change in Children's Literature ed. by Bettina Kümmerling-Meibauer and Anja Müller Deborah Stevenson (bio) Canon Constitution and Canon Change in Children's Literature, edited by Bettina Kümmerling-Meibauer and Anja Müller. Routledge 2017. Do you compulsively re-curate the Classics section in bookstores? Do you stay up late arguing with strangers on the Internet about the contemporary relevance of Gay-Neck, the Story of a Pigeon? Does the prospect of swapping out a title on your survey course syllabus leave you in a tizzy? Then you may be a canonist, and this book is for you. Edited by the estimable Bettina Kümmerling-Meibauer, professor of German at the University of Tübingen, and Anja Müller, professor of English literature and culture at the University of Siegen (both experienced critics on youth literature canons as well as aspects of the genre), this is a collection of essays stemming from a conference of the same title as the book, hosted by the editors, in Germany. The thirteen contributing scholars (plus Peter Hunt, who contributes a prelude) come from Israel, Denmark, Poland, Australia, Norway, the Netherlands, the UK, the US, and Germany; subject texts range from publication in the eighteenth century to publication in the twenty-first. Like all books in Routledge's Children's Literature and Culture series, it's smartly produced, with excellent front matter, essay notes and sourcing, and a capable index for you to use to remind yourself just which essay again was talking about The Bunyip of Berkeley's Creek. The result is a nonsystematic but broad look at canonicity that picks the issue up and looks at it from various angles, allowing illumination to shine through the topic. The assemblage fractures the monolithic notion of canons yet also reveals some commonalities in its creation (and in scholars' reactions to it). It's clear right from the introduction by Kümmerling-Meibauer and Müller, which capably covers the facets of discussion on canon, the tension between viewpoints, and the particular nature of its exploration in children's lit, that this is a knowledgeable but also gratifyingly opinionated exploration of the subject, and their acknowledgment that the included essays may sometimes contradict one another foregrounds the thoughtful and strongly argued individual points of view of the following chapters. The result is a collection engaging for those new to the topic, if not to critical analysis of children's literature in general, and also illuminating for veteran laborers in the canon mills. The recurrence of some themes and motifs is particularly revealing, given the diversity of topics and the diverse foundations on which [End Page 246] contributors stand. Many essays' introductions rehearse familiar notions/aspects/dimensions/facts about canonicity in a way that can be a little repetitive, but that also underscores the similarities of where we're starting in these conversations (and therefore proves particularly informative for readers new to this particular field of critical battle). The pragmatic lure of canons is clear throughout, especially in the section devoted to the canon and national identity, but also in several other places, such as Erica Hateley's essay about Australian book award committees and picture books. The tacit winner in the good old canon wars, referred to with understandable frequency within the volume, seems to be the notion of canon itself: there may be arguments about what goes in it, but if the subjects here are to serve as measure, belief in the utility and importance of the canon as tool is widespread and unflagging. (It slices! It dices! It signals your culture's values!) That exploration of national issues may be the book's dominant overall contribution. To this American reader working mostly in American canons, it's fascinating to see the work of countries consciously constructing national identity via youth literature canon. While US canons reveal many things about national identity and self-perception, nationalism is rarely an explicit criterion now that we're well past our Young Nation years; indeed, our canon creators are often willfully blind to how nation-specific the selections are and nation-specific the values they celebrate, even...

Os Estudos de etnometodologia de Garfinkel: uma investigação sobre os alicerces morais da vida pública moderna

Resumo A Editora Vozes publicou uma tradução em português da nova segunda edição de Estudos de etnometodologia. Para comemorar essa realização, falarei hoje a respeito da importância desse livro, da obra de Garfinkel em geral, em termos teóricos, metodológicos e políticos. Argumentarei que Garfinkel se dedicou ao projeto durkheimiano de fazer com que a sociologia se tornasse singularmente adequada para o estudo da modernidade, e que isso explica muitas das incompreensões sofridas por esta obra. Quero também anunciar as atividades do Arquivo Garfinkel (Garfinkel Archive), do qual sou hoje diretora e executora intelectual. Há materiais no arquivo que deverão se tornar o foco de importantes teses de pós-graduação e livros. O trabalho com esses arquivos vem sendo apoiado pelo governo alemão por meio de um centro na Universidade de Siegen, na Alemanha, denominado Mídia da Cooperação. O argumento de Garfinkel, assim como o de Durkheim, modifica o território epistemológico da ciência social e, com ele, o território teórico da argumentação social. Ele reorienta o domínio dos objetos, fazendo com que eles deixem de ser objetos naturais para se tornarem objetos sociais; vem como o domínio das práticas sociais relevantes, que deixam de ser normas, regras tradicionais e consensos, para se tornarem práticas constitutivas. Em razão da magnitude dessa reorientação, a etnometodologia só pode ser entendida por pessoas que já tenham uma compreensão teórica do que ela envolve. De outra forma, surgiriam contradições, o que de fato já aconteceu. A consequência do argumento de Garfinkel para entender a política democrática moderna é que quaisquer desigualdades ou exclusões que impeçam as pessoas de estar em condições de cumprir as condições de reciprocidade de uma interação (suas famosas “condições de confiabilidade”) são uma ameaça à coerência, ao significado e à identidade da vida pública democrática moderna.

Colossal triple-bladed claw latches swift louse flies to feathers

Why flap yourself when you can hitch a ride on your meal ticket? In fact, parasitic swift louse flies (Crataerina pallida) are so content to piggyback on the swifts upon which they dine that they have almost done away with their wings. Yet, should the louse flies lose their footing, all is lost. Dennis Petersen from Kiel University, Germany, says, ‘Swifts can fly really fast and the louse flies are incapable of flight, so detachment is normally a death sentence’. As most flies grip onto surfaces using a combination of a grappling hook and sticky attachment pads, Petersen and his colleagues Stanislav Gorb and Lars Heepe wondered how the blood-sucking swift parasites have adapted their feet to anchor themselves so firmly to their acrobatic hosts.The parasites reside as pupae in abandoned swift nests over winter, ready to emerge as adults when the swifts return to lay their eggs, so Arndt Wellbrock and Klaudia Witte from the University of Siegen, Germany, retrieved pupae from nests under a road bridge near Siegen before the adult flies emerged in spring. However, Petersen explains that it is impossible to rear the adult insects in the lab without a supply of fresh swift blood, ‘so we put them in a wine fridge at 10°C to cool them down and prolong their life’, he says. Nils Kreuter and Sebastian Büsse, also from Kiel University, then scrutinised the insect's feet using a scanning electron microscope and were impressed to see that the flies were equipped with a colossal claw, which is huge in comparison with the size of the insect and is split into three scythe-like blades. ‘The claw looks like a three-toothed comb’, says Petersen; however, a conventional comb would just slide through the barbs of a feather, so how were the insects locking on?Petersen allowed four louse flies to clamber onto swift feathers and fasten themselves on to reveal that the feather barbs become lodged in the tapering gaps between the claws’ curving blades, effectively clamping the parasite in place. In addition, Petersen and Büsse could see that the sticky foot pads – the pulvilli, which other flies use to attach themselves to smooth surfaces – were coated in minute double-headed petal-shaped hairs that also snag on the feather. Next, Petersen and Kreuter tugged on the feet of flies that were clamped onto feathers and they were amazed that each individual leg could grip on with a force of 200 mN – 1000 times the weight of the fly; with six legs, nothing could tear the parasite free.Having tested the louse flies’ ability to latch onto feathers, the team also investigated how well they attach to smoother surfaces, as the parasites often encounter egg shell, the skin of naked nestlings and plant fragments in the nest. Encouraging the flies to scamper over smooth glass, silicone and epoxy resin, in addition to ridged versions of the silicone and epoxy resin, Kreuter and Petersen found that the insects could grip onto the smooth epoxy resin and glass with forces (∼15 mN) that were 75 times greater than their weight, but only 25 times greater (∼4 mN) on smooth silicone. However, when the insects were provided with 1.6 mm ridges to grip onto, their grasp on the epoxy resin and silicone was even tighter (∼19.5 mN and ∼19.4 mN, respectively).‘We were really surprised about the high interlocking forces observed on feathers’, says Petersen, who admits that it was impossible to detach the louse flies without damage to them or the feathers and is eager to find out whether, and how, other parasites get their claws into their hosts.

THE CONVENTION ON THE RIGHTS OF PERSONS WITH DISABILITIES UN: ANALYSIS OF THE IMPLEMENTATION IN ANDALUCÍA (SPAIN) OF ARTICLE 33

The United Nations Convention on the Rights of Persons with Disabilities is a major human rights instrument of the United Nations with the goal of ensuring protection of rights of persons with disabilities. In Article 33, ‘National implementation and monitoring’ establishes, among other things, that States Parties shall implement the Convention and establish or designate a coordination mechanism at government level. This article aims to show the results of implementing Article 33 in Andalucía (Spain) in the context of the European project ‘Planning Inclusive Communities’ led by the University of Siegen (Germany). The methodology used in this study was based on a comparative analysis of data obtained through a series of surveys addressed to local governments in different European regions. This article shows the results obtained in Andalucía region where the Convention is disseminated in various formats, at local levels it shows a low presence, because rati cation have neither led to a legal obligation at lower state levels. Local managers showed disregard for the principles of the Convention and its practical application. This lack of information at local level in uences the methods that Spanish occupational therapists (OT) use with persons with disabilities in occupational centers (OC).

Development of the cycloidal propeller StECon as a new small hydropower plant for kinetic energy

The StECon (Stiller Energy Converter) is a promising new small hydropower plant for kinetic energy. It is an invention of Mr. Hans-Ludwig Stiller and has several advantages compared to the technologies for the use of hydropower known for millennia. It runs completely submerged forwards and backwards, with horizontal or vertical axis and has a compact design by using a single or a double-sided planetary gear with optimum alignment to the flow direction. The possible applications include mobile and stationary tide and current generators as well as hybrid solutions, either as a generator or as a propulsion system. The high expectations have to be confirmed in a research project StEwaKorad at the University of Siegen. Aim of this research project is to investigate the performance and characteristics of the StECon as an energy converter for producing renewable energy from hydropower with low fall heights including sea currents.

Dedication

Dedication

A facility for testing the aerodynamic and acoustic performance of bidirectional air turbines for ocean wave energy conversion

Bidirectional air turbines are used in oscillating water column (OWC) power plants for harnessing ocean wave energy. This paper describes the bidirectional aerodynamic and aero-acoustic facility at the University of Siegen for model air turbines performance testing. At least nine test facilities are known worldwide, but their layout, the performance testing procedure and the presentation of performance data are not standardized to this day. The layout of the facility at the University of Siegen follows ideas in ISO 5801 for fan performance testing. The pressurized air supply is bidirectional but steady-state. Achievable values of Reynolds and Mach number of the test turbines are 1,000,000 and 0.5, respectively. In addition, the facility is equipped with acoustic attenuators in the air supply for allowing synchronous determination of aerodynamic and acoustic characteristics of a turbine.A good practice guideline for turbine performance testing and presentation is proposed by showing full sets of non-dimensional aerodynamic and acoustic performance characteristics from two sample model turbines. Eventually, a comparison of in situ data from a full-scale turbine in transient operation with scaled up steady-state model performance measurements underlines the usefulness of steady-state model performance testing.

LAVES: An Extensible Visualization Tool to Facilitate the Process of Learning and Teaching Algorithms

The Logistics Algorithms Visualization and Education Software (LAVES) is an open source project at the University of Siegen, aiming at supporting business and business informatics students in understanding the basic concepts of algorithms that are applied to solve problems arising in operations research, especially in logistics, by means of visualization. It allows students to create problem instances click-by-click with direct graphical feedback, offers a set of algorithm-related controls, presents execution-table-views as used by the students when manually processing algorithms, depicts and highlights the related pseudocode (including [Formula: see text] formulas), and includes an exercise mode. LAVES is accompanied by a development kit (LAVESDK) that allows instructors (with Java knowledge) to implement course-specific algorithm visualizations (called plugins) to be used with LAVES. The development kit is generic and provides a broad range of tools. In this paper, we present the basic features of LAVES and LAVESDK and report on first classroom experiences and student feedback.

On the Value of Hydrological Models Developed in the Context of Undergraduate Education for Discharge Prediction and Reservoir Management

A conceptual hydrological catchment model called ‘student model’ is introduced which has been interactively developed within an undergraduate course on hydrological modelling at Siegen University (BSc Civil Engineering). After successful model calibration and model validation to a German mesoscale catchment, the ‘student’ model is applied to quantify the impact of regional climate change scenarios on the water budget of the Wiehl drinking water reservoir. The simulation results show that the conceptual ‘student model’ performs well for both calibration and validation periods. It well represents the variability in water flows at different timescales and therefore has the potential to be used for scenario analysis. The ‘student model’ shows a comparable reaction to climate change scenarios as sophisticated hydrological catchment models did which were applied to neighboured catchments in North Rhine-Westphalia based on the same underlying parent scenarios. The magnitude of the simulated climate impacts on seasonal water balances and extreme flows indicates that current reservoir management needs to be adjusted to the projected variability of inflows to the reservoir. Despite its simplicity, the ‘student model’ can have a high value for reservoir management. It well represents the inflow into the reservoir based on available data and provides a reliable estimate of climate change impacts, indicating the necessity of adjustment of the operation rules in the future. At the same time it remains transparent to the model users, offering a simple but realistic training tool for the generation of reservoir inflow time series. It therefore can contribute to the solution of recent hydrological and water management problems. Restrictions of such models are due to the lumped nature and the limited applicability for a priori predictions.

Structural Dynamical Monitoring and Fault Diagnosis

1College of Mechanical and Electrical Engineering, Wenzhou University, Wenzhou 325035, China 2School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049, China 3Department of Mechanical Engineering, Technology University of Darmstadt, 64289 Darmstadt, Germany 4Department of Structural Engineering, University of California, San Diego, CA 0085, USA 5Department of Civil Engineering, University of Siegen, 57076 Siegen, Germany

Speed Control of Unmanned Ground Vehicle for Non Autonomous Operation

This paper describes the development of speed control for non autonomous robotic vehicle for driving under a difficult conditions surveillance. The DORIS project developed at Siegen University's Institute for Real Time Learning Systems. The primary aim of the DORIS project is to develop novel mobile and unmanned ground Vehicle platforms that will extend the sphere of awareness and mobility of military units and working in difficult condition on the land and on the water. The research is focused to build the platform a, design and install the power train system, control systems, electronic systems that make the vehicle in future full automated. In this paper, the hardware system, control architecture, sensor suite, current capabilities, future research, and applications for the robotic ATV (DORIS) are described. 

Vom Tagging zur Domäne. Neue curriculare Wege zur Alphabetisierung und Grundbildung Jugendlicher

The article describes the results of a research project at Siegen University, which addressed the alphabetization and basic education of young adults. Following the social civil code, alphabetization is defined as the possibility of cultural participation. This understanding of alphabetization shapes the conceptual design of the research project: Neither could it only focus on answering the questions of functional alphabetization nor on the acquisition of single abilities, skills and knowledge by students. The project rather strived to develop curricular solutions that should enable teenagers to understand the meaning of the learning process itself and to comprehend the relevance of learning processes for their personal development. Therefore, we developed and tested specific contents for learning processes which take into account the interests, experiences and ideas of the young adults: Media projects, dance theaters, exhibitions or regional-specific projects in different domains.

Assessment method of sound radiated by cyclically operating Wells turbines

The oscillating water column (OWC) is a system for sea wave energy conversion. This paper deals with the axial Wells turbine. Main objectives of this study are the experimental determination of aerodynamic and aero-acoustic characteristics of a laboratory scale turbine and their subsequent usage for full scale turbine performance prediction.For that a model Wells turbine was built and tested on a laboratory test rig at the University of Siegen. Assuming that the steady-state characteristics hold in unsteady operation, mean quantities such as a mean efficiency and an equivalent sound power level are defined that allow the quantification of the overall performance during cyclic operation. The steady-state quantities are used to assess various control strategies and to predict the aero-acoustic performance of the full scale LIMPET turbine on Islay, Scotland.In general, scaled-up acoustic laboratory test rig data correlates well with measurements from the full scale LIMPET turbine. A theoretical assessment of different control strategies under regular wave conditions demonstrates the potential of a variable speed control for reduction of equivalent sound power. Turbine operation which admits stall yields a typical signature in the equivalent sound power spectrum: a stalled Wells turbine emits low frequency noise at a level far above all levels encountered in the unstalled flow regime and hence significantly contributes to the equivalent sound power.

Designing sustainable production systems with 'GraFem'

The at the University of Siegen developed production system modelling method ‘GraFem’ allows a function-orientated depiction of a manufacturing system with help of a predefined set of symbols and an underlying semantics. Through this, manufacturing systems can be regarded at any level of detail. The depiction of the manufacturing system can be added by additional ‘swimming lanes’ that contain differentiated information such as weak points and potentials or even sources of waste. At this, the possibility of multiple views constitutes one specific feature of ‘GraFem’. Thus, it is in particular possible to focus on the examination of sources of waste as for example the dissipation of energy. The paper presents this specific view of ‘GraFem’ that can help to endorse manufacturing in terms of sustainability.

Evaluation eines Lehrkonzepts in EbM für Lehramtsstudierende der Biologie – eine kontrollierte Phase-II-Studie (NCT01567267)

Consumers increasingly demand to take part in healthcare decisions as described by the concept of shared decision making. In order to ensure this happens the patient must be able to critically appraise the healthcare information provided, which is called critical health literacy. Critical health literacy can be taught to patients at the onset of their disease to enable them to obtain information about interventions and alternatives. For the primary prevention of common diseases like hypertension or diabetes mellitus, though, it is necessary to empower consumers to critically appraise medical information since this information is routinely presented in the mass media. This might be achieved through educational intervention programmes at school. The study was designed as a prospective controlled trial with students in training to become biology teachers at Siegen University (Germany). The intervention group received a short-term educational intervention (24 units) in human biology based on the principles of Evidence-based Medicine (EbM) and Good Scientific Practice (GSP) combined with elements of problem-based learning. The control group received a short-term intervention in human biology of equal duration, but without the elements of EbM and GSP. Knowledge and skills were evaluated by validated questionnaires and case studies in a pre-, interim, and post-interventional test in both groups. In addition, biology trainee teachers in the intervention group also planned and conducted a one-hour problem-based learning session with high school students, which was evaluated by video. The increase in knowledge (7.9±3.8 points vs. 2.7±2.5 points, p≤0.001) and appraisal skills (24.1±6.7 points vs. 14.6±6.3, p≤0.001) after the intervention was relevant and significant compared to baseline results and also compared to the control group that did not show any significant progress in knowledge (3.9±2.4 points vs. 2.7±1.7) and appraisal skills (16.2±5.9 points vs. 14.4±5.6). All the participants in the intervention group passed both the preparation and the conduction of their problem-based learning session with high school students with at least 50% of the maximum number of points. Satisfaction among students in training to become biology teachers (median grade of 2 [good] in the German grading system) and students (89% of students agreed this to be an interesting method) were high in the intervention group. This preliminary study showed a relevant increase in knowledge about EbM and skills in critically appraising interventional studies. Participating students were able to conduct problem-based learning sessions for high school students about the principles of EbM and GSP. The results justify a larger randomised controlled trial to evaluate both effects and applicability to different school settings.

Study Abroad and Language Learning

AbstractFolk LinguisticsThe AILA Research Network on Folk Linguistics, convened by Antje Wilton (University of Siegen, Germany) and Martin Stegu (Vienna University of Economics and Business), held a very successful thematic session at the Soliolinguistics Symposium 19 in Berlin. We were very pleased to have our session approved – especially as the Sociolinguistics Symposium has grown into a large and internationally renowned platform for sociolinguists around the world. The call for papers invited contributions on our session topic, Folk linguistics and society: People's ideas about language use and social identity, and was met with an overwhelming response of 35 submissions. Eventually, we managed to hear 19 of them in a tight schedule extending over three days of the entire conference. The papers presented research on non‐linguists' perceptions of language in the formation of social identity from various regions of the world and stressed the necessity of taking such views into account in any situation in which decisions about language are made, such as language teaching and language policy and planning. The session finished with a discussion on folk linguistic issues to which we were able to welcome Prof. Dennis Preston, one of the great figures in and founders of folk linguistics and valued member of our network. Both the paper presentations as well as the final discussion attracted a large and interested audience throughout the session. The session showed clearly that folk linguistic research, its interest and its methodologies have firmly established themselves among the approaches in sociolinguistics as well as applied linguistics. Furthermore, it testifies to the successful work of the Research Network over the last seven years.

Promoting the Positive Development of Foster Children: Establishing Research in Germany

Research into foster care is less developed in Germany than in the UK or US and there are few national practice standards. In 2006, a research centre was established at the University of Siegen to improve the situation. Klaus Wolf describes the work undertaken so far and discusses the aims and philosophy underpinning the programme. He explains how research relevant to practice is combined with studies that have theoretical value in their own right, and how a combination of these informs current debates about foster care in Germany and elsewhere.