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Search Results: 1 - 10 of 148007 matches for " Marc K?rschen "
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Neue Techniken der qualitativen Gespr chsforschung: Computergestützte Transkription von Videokonferenzen New Techniques in Qualitative Conversation Analysis: Computer-based Transcription of Videoconferences Nuevas técnicas en análisis de conversación cualitativa: Transcripción de vídeo-conferencias a través de computadoras
Marc Krschen,Jessica Pohl,Walter Schmitz,Olaf A. Schulte
Forum : Qualitative Social Research , 2002,
Abstract: Jede qualitative Gespr chsforschung muss mit einer pr zisen Bestimmung der zu untersuchenden Ereignisse und Prozesse beginnen, und dieser sind dann die Verfahren der Beobachtung und Beschreibung, der Aufzeichnung und der Transkription anzupassen, und nicht umgekehrt. Für das DFG-Projekt "Audiovisuelle Fernkommunikation" an der Universit t Essen, das seit Februar 2000 die Nutzung von Videokonferenzen als eine Form technisch vermittelter Kommunikation untersucht, bedeutet dies, dass für das kommunikative Ereignis "Videokonferenz" unter Berücksichtigung seiner spezifischen Merkmale – insbesondere unterschiedliche Wahrnehmungsbedingungen aufgrund der r umlichen Trennung und technisch bedingte zeitliche Verz gerungen der Gespr chsbeitr ge zwischen den beiden Standorten – angemessene Mess- und Transkriptionsverfahren entwickelt werden müssen. Denn nur auf diese Weise und keineswegs schon durch die Mehrfachbetrachtung der Videoaufzeichnung wird die Kommunikation per Videokonferenz einer qualitativen Gespr chsforschung zug nglich gemacht. Vor dem Hintergrund bisher verwendeter Verfahren zur Transkription von Videokonferenzen erscheint dies um so dringlicher, als diese meist übernahmen oder Modifikationen konventioneller Vorgehensweisen darstellen, die ihrerseits den spezifischen Merkmalen der audiovisuellen Fernkommunikation nicht gerecht zu werden verm gen. Denn durch die technische Vermittlung entstehen z.B. zwei getrennte, aber letztlich doch zusammengeh rige Sequenzen kommunikativer Ereignisse. Um diesem Umstand im Transkript gerecht zu werden, bedarf es einer Synchronisation der Aufzeichnungen der an der Videokonferenz beteiligten Standorte in einem, den gesamten Kommunikationsprozess wiedergebenden Transkript; hierfür wiederum bedarf es einer Orientierung an einer objektiven Zeitleiste. Dabei erlaubt erst eine "Timeline" mit framegenauer Einteilung (1/25 Sekunden) eine detaillierte Analyse einzelner kommunikativer Besonderheiten, wie etwa der zeitlichen Verz gerung der Backchannel-Signale. Im Gegensatz dazu kann das Transkript verbaler u erungen weder das zeitliche Geschehen hinreichend abbilden noch als Zuordnungsleiste für die Transkription nonverbaler Elemente ausreichen. Als Vorschlag zur L sung der genannten Probleme wird eine modifizierte und derart erweiterte Version des multimedialen Transkriptionsverfahrens ComTrans vorgestellt, das die spezifischen Merkmale der Videokonferenzkommunikation erfasst und für qualitative Analysen hinreichend umfassend abgebildet werden k nnen. Dadurch entstehen neue M glichkeiten für die qualitative Sozialforschung,
Physics and Applications of Laser Diode Chaos
Marc Sciamanna,K. Alan Shore
Physics , 2015, DOI: 10.1038/nphoton.2014.326
Abstract: An overview of chaos in laser diodes is provided which surveys experimental achievements in the area and explains the theory behind the phenomenon. The fundamental physics underpinning this behaviour and also the opportunities for harnessing laser diode chaos for potential applications are discussed. The availability and ease of operation of laser diodes, in a wide range of configurations, make them a convenient test-bed for exploring basic aspects of nonlinear and chaotic dynamics. It also makes them attractive for practical tasks, such as chaos-based secure communications and random number generation. Avenues for future research and development of chaotic laser diodes are also identified.
Prevalence and Risk Factors of Gastrointestinal Parasitic Infections in Small Ruminants in the Greek Temperate Mediterranean Environment  [PDF]
Vaia Kantzoura, Marc K. Kouam, Helen Theodoropoulou, Haralambos Feidas, Georgios Theodoropoulos
Open Journal of Veterinary Medicine (OJVM) , 2012, DOI: 10.4236/ojvm.2012.21005
Abstract: Gastrointestinal (GI) parasitic infections of sheep and goats were investigated in 69 farms located in Thessaly region of Greece, characterized by temperate Mediterranean climate, during two consecutive seasons. A total of 557 fecal samples were collected. Helminth eggs were detected in 44 (7.9%) samples. Strongyle-type eggs were found in 19 (3.4%) samples, Nematodirus spp. eggs in 6 (1.1%) samples, Trichuris spp. eggs in 16 (2.9%) samples, Fasciola hepatica in 3 (0.5%) samples, and Dicrocoelium dendriticum in 1 (0.2%) sample. Coccidian oocysts were found in 36 (6.5%) samples. Risk factors related to animal and farmer status, farm and pasture management, and environmental factors derived by satellite data were examined for their association with the prevalence of helmith infections. A logistic regression model showed that the educational level of farmers and the elevation of farm location were associated with helminth infections
Benefits and Costs of Improved Cookstoves: Assessing the Implications of Variability in Health, Forest and Climate Impacts
Marc A. Jeuland, Subhrendu K. Pattanayak
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0030338
Abstract: Current attention to improved cook stoves (ICS) focuses on the “triple benefits” they provide, in improved health and time savings for households, in preservation of forests and associated ecosystem services, and in reducing emissions that contribute to global climate change. Despite the purported economic benefits of such technologies, however, progress in achieving large-scale adoption and use has been remarkably slow. This paper uses Monte Carlo simulation analysis to evaluate the claim that households will always reap positive and large benefits from the use of such technologies. Our analysis allows for better understanding of the variability in economic costs and benefits of ICS use in developing countries, which depend on unknown combinations of numerous uncertain parameters. The model results suggest that the private net benefits of ICS will sometimes be negative, and in many instances highly so. Moreover, carbon financing and social subsidies may help enhance incentives to adopt, but will not always be appropriate. The costs and benefits of these technologies are most affected by their relative fuel costs, time and fuel use efficiencies, the incidence and cost-of-illness of acute respiratory illness, and the cost of household cooking time. Combining these results with the fact that households often find these technologies to be inconvenient or culturally inappropriate leads us to understand why uptake has been disappointing. Given the current attention to the scale up of ICS, this analysis is timely and important for highlighting some of the challenges for global efforts to promote ICS.
Exploring spatial patterns and hotspots of diarrhea in Chiang Mai, Thailand
Nakarin Chaikaew, Nitin K Tripathi, Marc Souris
International Journal of Health Geographics , 2009, DOI: 10.1186/1476-072x-8-36
Abstract: The objective of this study was to analyse the epidemic outbreak patterns of diarrhea in Chiang Mai province, Northern Thailand, in terms of their geographical distributions and hotspot identification. The data of patients with diarrhea at village level and the 2001–2006 population censuses were collected to achieve the objective. Spatial analysis, using geographic information systems (GIS) and other methods, was used to uncover the hidden phenomena from the data. In the data analysis section, spatial statistics such as quadrant analysis (QA), nearest neighbour analysis (NNA), and spatial autocorrelation analysis (SAA), were used to identify the spatial patterns of diarrhea in Chiang Mai province. In addition, local indicators of spatial association (LISA) and kernel density (KD) estimation were used to detect diarrhea hotspots using data at village level.The hotspot maps produced by the LISA and KD techniques showed spatial trend patterns of diarrhea diffusion. Villages in the middle and northern regions revealed higher incidences. Also, the spatial patterns of diarrhea during the years 2001 and 2006 were found to represent spatially clustered patterns, both at global and local scales.Spatial analysis methods in GIS revealed the spatial patterns and hotspots of diarrhea in Chiang Mai province from the year 2001 to 2006. To implement specific and geographically appropriate public health risk-reduction programs, the use of such spatial analysis tools may become an integral component in the epidemiologic description, analysis, and risk assessment of diarrhea.Diarrhea is a major public health problem in Thailand. The Ministry of Public Health, Thailand, has been trying to monitor and control this disease for many years. The objective of this study was to analyse the epidemic outbreak patterns of diarrhea in Chiang Mai province, Northern Thailand, in terms of their geographical distributions and hotspot identification. The methodology and the results could be useful for
Determination of albuminuria in the urine of diabetics for prevention and control of diabetic nephropathy
Schroeder, Andreas,Heiderhoff, Marc,K?bberling, Johannes
GMS Health Technology Assessment , 2005,
Abstract: The issue: Diabetes has become the main cause of endstage renal disease. The costs for the treatment of diabetic patients with endstage renal disease have increased in the last years and have become a relevant economic topic of the health service. The first unspecific predictor of a diabetic nephropathy is an albuminuria. The screening for diabetic nephropathy uses microalbuminuria as a proof. Objectives: * What significance does the determination of albuminuria have on the precaution and course-control of the diabetic nephropathy? a) in type 1 diabetic patients, b) in type 2 diabetic patients * Which is an appropriate time to determine the albuminuria for the purpose of precaution and course-control of the diabetic nephropathy? a) in type 1 diabetic patients, b) in type 2 diabetic patients * Which method of testing is most effective concerning economic and medical aspects? Methods: Published literature from 1998 up to 2004 was identified by searching in the most important databases. Most of the guidelines were found by hand searching in the internet. Results: Of 2,792 citation titles and abstracts examined, 274 articles were retrieved for full-text review. Five metaanalyses and reviews, one review about clearing of guidelines (regarding 18 international guidelines) and four guidelines met the inclusion criteria for screening for microalbuminuria and type 1 diabetes. Seven metaanalyses, one HTA report, one review about clearing of guidelines (regarding 17 international guidelines), and seven guidelines met the inclusion criteria for screening for microalbuminuria and type 2 diabetes.At the moment, the determination of albuminuria still has a great significance because it is recommended in most published literature and guidelines. The time to determine the albuminuria depends on the age of the patients and their type of diabetes. Type 2 diabetic patients should start the determination when the diabetes is diagnosed whereas the determination is recommended five years later when type 1 diabetic patients are concerned. Most guidelines recommend a screening for microalbuminuria every year. Discussion and conclusion: All guidelines and most of the literature recommend this screening. However, these recommendations are only based on expert consensus. The specificity of this screening is rather low. False positive tests in type 2 diabetic patients will cause psychological problems. A positive test leads to the recommendation to achieve "normal blood pressure" and "normoglycaemia" - but this applies to each diabetic patient. Based on these facts, the screening f
Towards empowering learners in a democratic mathematics classroom: To what extent are teachers’ listening orientations conducive to and respectful of learners’ thinking?
Michael K. Mhlolo,Marc Sch?fer
Pythagoras , 2012,
Abstract: In an effort to make education accessible, to ‘heal the divisions of the past and establish a society based on democratic values’, the South African Department of Education claims that a series of mathematics reforms that has so far been introduced is underpinned by the principles of ‘social justice, fundamental human rights and inclusivity’. Critics however argue that the system has remained ‘undemocratic’ in that those groups of learners who were supposed to be ‘healed’ continue to underperform and hence be disempowered. In this study, we conceptualised a democratic and mathematically empowering classroom as one that is consistent with the principle of inclusivity and in which a hermeneutic listening orientation towards teaching promotes such a democratic and mathematically empowering learning environment. We then worked with three different orientations teachers might have towards listening in the mathematics classroom: evaluative, interpretive and hermeneutic. We then used these orientations to analyse 20 video-recorded lessons with a specific focus on learners’ unexpected contributions and how teachers listened and responded to such contributions. The results were consistent with the literature, which shows that teachers tend to dismiss learners’ ways of thinking by imposing their own formalised constructions.
Large scale bias and the inaccuracy of the peak-background split
Marc Manera,Ravi K Sheth,Roman Scoccimarro
Physics , 2009, DOI: 10.1111/j.1365-2966.2009.15921.x
Abstract: The peak-background split argument is commonly used to relate the abundance of dark matter halos to their spatial clustering. Testing this argument requires an accurate determination of the halo mass function. We present a Maximum Likelihood method for fitting parametric functional forms to halo abundances which differs from previous work because it does not require binned counts. Our conclusions do not depend on whether we use our method or more conventional ones. In addition, halo abundances depend on how halos are defined. Our conclusions do not depend on the choice of link length associated with the friends-of-friends halo-finder, nor do they change if we identify halos using a spherical overdensity algorithm instead. The large scale halo bias measured from the matter-halo cross spectrum b_x and the halo autocorrelation function b_xi (on scales k~0.03h/Mpc and r ~50 Mpc/h) can differ by as much as 5% for halos that are significantly more massive than the characteristic mass M*. At these large masses, the peak background split estimate of the linear bias factor b1 is 3-5% smaller than b_xi, which is 5% smaller than b_x. We discuss the origin of these discrepancies: deterministic nonlinear local bias, with parameters determined by the peak-background split argument, is unable to account for the discrepancies we see. A simple linear but nonlocal bias model, motivated by peaks theory, may also be difficult to reconcile with our measurements. More work on such nonlocal bias models may be needed to understand the nature of halo bias at this level of precision.
Electron properties of fluorinated single-layer graphene transistors
Freddie Withers,Marc Dubois,Alexander K. Savchenko
Physics , 2010, DOI: 10.1103/PhysRevB.82.073403
Abstract: We have fabricated transistor structures using fluorinated single-layer graphene flakes and studied their electronic properties at different temperatures. Compared with pristine graphene, fluorinated graphene has very large and strongly temperature dependent resistance in the electro-neutrality region. We show that fluorination creates a mobility gap in graphene's spectrum where electron transport takes place via localised electron states.
Experimental Study on Bouncing Barriers in Protoplanetary Disks
Thorben Kelling,Gerhard Wurm,Marc K?ster
Physics , 2014, DOI: 10.1088/0004-637X/783/2/111
Abstract: For dust aggregates in protoplanetary discs a transition between sticking and bouncing in individual collisions at mm to cm size has been observed in the past. This lead to the notion of a bouncing barrier for which growth gets stalled. Here, we present long term laboratory experiments on the outcome of repeated aggregate collisions at the bouncing barrier. About 100 SiO$_2$ dust aggregates of 1 mm in size were observed interacting with each other. Collisions occured within a velocity range from below mm/s up to cm/s. Aggregates continuously interacted with each other over a period of 900 s. During this time more than $10^5$ collisions occured. Nearly 2000 collisions were analyzed in detail. No temporal stable net growth of larger aggregates was observed even though sticking collision occur. Larger ensembles of aggregates sticking together are formed but were disassembled again during the further collisional evolution. The concept of a bouncing barrier supports the formation of planetesimals by seeded collisional growth as well as by gravitational instability favouring a significant total mass being limited to certain size ranges. Within our parameter set the experiments confirm that bouncing barriers are one possible and likely evolutionary limit of a self consistent particle growth.
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