2,077 research outputs found
The Dewoitine D.332 commercial airplane (French) : a three-engine all-metal low-wing monoplane
Savoia Marchetti "S 64" Airplane
The S 64 is a large monoplane with an aspect ratio of 7. It has a cantilever wing made of a single piece, entirely of wood. The wing has three spars with a covering of plywood. The engine is mounted high over the wing's center. It was designed for long distance transatlantic flights
Influence of Staff Discipline and Attitude to Work On Job Satisfaction Lecturers in Tertiary Institutions in Cross River State
The paper examines the influence of staff discipline and attitude to work on job satisfaction of Lecturers in tertiary institution in Cross River State. A forty-item four point-liker survey questionnaire was used for data collection. A total of 400 lecturers (200 males and females) out of a population of over 2,000 were chosen. Four (4) hypotheses were formulated for the study. The data generated was analyzed using Person Product Moment Correlation Analysis and Analysis of Variance (ANOVA). The result of study revealed that lecturers who have high, moderate, or low perception of how a staff is disciplined do not differ in their level of job satisfaction. Also, lecturers’ attitude towards classroom teaching, lecturers’ attitude towards the tasks of disciplining students, lecturers’ attitudes towards supervision of instructions and lecturers’ attitude towards classroom management do not significantly relate to their job satisfaction. The result of the study showed a significant relationship between lectures recognition and their job satisfaction. Based on the findings, the following recommendations are made, inter-alia: to ensure appropriate staff discipline there is need for a enabling teaching environment to be created. Lecturers should be properly rewarded for their effort through improve conditions of serves. In-service training for all lecturers should be made compulsory to enhance their job satisfaction. Keywords: Discipline; job satisfaction, tertiary institutions; in-service training; attitude to work
Classical metric Diophantine approximation revisited
The idea of using measure theoretic concepts to investigate the size of
number theoretic sets, originating with E. Borel, has been used for nearly a
century. It has led to the development of the theory of metrical Diophantine
approximation, a branch of Number Theory which draws on a rich and broad
variety of mathematics. We discuss some recent progress and open problems
concerning this classical theory. In particular, generalisations of the
Duffin-Schaeffer and Catlin conjectures are formulated and explored.Comment: 31 pages, Dedicated to Klaus Roth on the occasion of his 80th
birthda
Semantic enrichment of GPS trajectories
Semantic annotation of GPS trajectories helps us to recognize the interests of the creator of the GPS trajectories. Automating this trajectory annotation circumvents the requirement of additional user input. To annotate the GPS traces automatically, two types of automated input are required: 1) a collection of possible annotations, and 2) a collection of GPS trajectories to annotate.\ud
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The first type of input can be a set of points of interest (POIs), activities, weather types, etc. This collection is to be provided by an application developer, and can originate from the web, an external knowledge base, or an existing database, for example.\ud
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The type of annotation that we are interested in, is annotation with visited locations, in order to create a user profile at a later stage. We have collected POIs by scraping the web, using a self-configuring data harvester. This harvester is based on workflows, enabling us to add or remove certain steps for different goals of harvesting.\ud
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The result of our harvesting approach consists of a set of 27,384 POIs, origining from the Dutch Yellow Pages \cite{goudengids2012, and contains an address and a geographical point representation for each POI. These point representations cannot be used to overlay the GPS trajectories directly, and therefore need to be converted into a polygon before providing useful input for the annotation process.\ud
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Several different approaches to this problem can be thought of, including Voronoi diagrams, nearest-neighbors, and geocoding the addresses of the assumed neighbors. For each of the POI footprint size estimation approaches, the output consists of two parts: 1) a polygon representing the estimated parcel, and 2) an uncertainty function based on the distance to the center of the polygon. These approaches are being validated with cadastral data for the region of Enschede, The Netherlands, and the result of the best approach is used as the input for the GPS trajectory enrichment.\ud
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The other type of input for the enrichment process is GPS trajectories. This data is generally not smooth, containing outliers, and interruptions of the data stream. Analyzing these imperfections however, may provide valuable information on users entering a rural area, or buildings, respectively.\ud
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Combining the results of the footprint size estimation with the analyzed GPS trajectory then provides us with uncertain annotated GPS traces
Automated semantic trajectory annotation with indoor point-of-interest visits in urban areas
User trajectories contain a wealth of implicit information. The places that people visit, provide us with information about their preferences and needs. Furthermore, it provides us with information about the popularity of places, for example at which time of the year or day these places are frequently visited. The potential for behavioral analysis of trajectories is widely discussed in literature, but all of these methods need a pre-processing step: the geometric trajectory data needs to be transformed into a semantic collection or sequence of visited points-of-interest that is more suitable for data mining. Especially indoor activities in urban areas are challenging to detect from raw trajectory data. In this paper, we propose a new algorithm for the automated detection of visited points-of-interest. This algorithm extracts the actual visited points-of-interest well, both in terms of precision and recall, even for the challenging urban indoor activity detection. We demonstrate the strength of the algorithm by comparing it to three existing and widely used algorithms, using annotated trajectory data, collected through an experiment with students in the city of Hengelo, The Netherlands. Our algorithm, which combines multiple trajectory pre-processing techniques from existing work with several novel ones, shows significant improvements
Spatiotemporal behavior profiling: a treasure hunt case study
Trajectories have been providing us with a wealth of derived information such as traffic conditions and road network updates. This work focuses on deriving user profiles through spatiotemporal analysis of trajectory data to provide insight into the quality of information provided by users. \ud
The presented behavior profiling method assesses user participation characteristics in a treasure-hunt type event. Consisting of an analysis and a profiling phase, analysis involves a timeline and a stay-point analysis, as well as a semantic trajectory inspection relating actual and expected paths. The analysis results are then grouped around profiles that can be used to estimate the user performance in the activity.\ud
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The proposed profiling method is evaluated by means of a student orientation treasure-hunt activity at the University of Twente, The Netherlands. The profiling method is used to predict the students' gaming behavior by means of a simple team type classification, and a feature-based answer type classification
Generic knowledge-based analysis of social media for recommendations
Recommender systems have been around for decades to help people find the best matching item in a pre-defined item set. Knowledge-based recommender systems are used to match users based on information that links the two, but they often focus on a single, specific application, such as movies to watch or music to listen to. In this presentation, we present our Interest-Based Recommender System (IBRS). This knowledge-based recommender system provides recommendations that are generic in three dimensions: IBRS is (1) domain-independent, (2) language-independent, and (3) independent of the used social medium. To match user interests with items, the first are derived from the user's social media profile, enriched with a deeper semantic embedding obtained from the generic knowledge base DBpedia. These interests are used to extract personalized recommendations from a tagged item set from any domain, in any language. We also present the results of a validation of IBRS by a test user group of 44 people using two item sets from separate domains: greeting cards and holiday homes
//Rondje Zilverling: COMMIT/TimeTrails
Het TimeTrails-project3 gaat over data mining in grote hoeveelheden gegevens over gebeurtenissen in ruimte en tijd, d.w.z. met coördinaten en time-stamps. Dergelijke gegevens worden doorgaans vergaard door mensen, sensoren en wetenschappelijke observaties. Gegevensanalyse richt zich vaak op de vier W’s: Wie, Wat, Waar en Wanneer. Een belangrijke kwestie is het kunnen behappen van de grote hoeveelheden gegevens, d.w.z. "big data". Vanuit de UT werken we, d.w.z. de groepen EWI/DB en ITC/GIP, aan twee applicaties:\ud
* Het in kaart brengen van de mening van het publiek bij grote infrastructuurproject zoals de aanleg van een nieuw stuk snelweg. Dit doen we met Twitter-analyse en data-visualisatie.\ud
• Het vinden van goede vakantiebestemmingen. Hierbij spelen Social media, web harvesting en analyse van GPS-traces een rol
The Effect of Ordered Water on a Short, Strong (Speakman-Hadži) Hydrogen Bond
We have determined the structures of the sodium, tetrabutylam- monium (TBA) and bis(triphenylphosphoranylidene)ammonium (PNP) salts of the bis(4-nitrophenoxide) anion by X-ray crystallography. The sodium salt is a dihydrate, with the water oxygens coordinated to the sodium cations, and one hydogen from each water hydrogen bonded to one of the bridging oxygens of the anion.
The TBA and PNP salts are anhydrous. Nevertheless the oxygen- oxygen distance is shortest in the sodium salt; 246.5 pm in the sodium salt, 247.5 pm in the TBA salt, and 249 pm in the PNP salt; suggesting that the hydrogen bond is not weakened by the water, and may be strongest in the hydrated salt. (All three compounds show Hadži type ii IR spectra, and are called Speakman-Hadži compounds in this paper.) The 2H chemical shifts of the bridging hydrogen in the three solids are 16.8 ppm for the sodium salt, 16.8 ppm for the TBA salt, and 16.5 ppm for the PNP salt. Again there is no evidence that the water weakens the hydrogen bond. These results can be understood by noting that the additional hydrogen bonds to the bridging oxygens decrease their proton affinity, but the mutual repulsion of the oxygens is also decreased
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