A true virtual window

Previous research from environmental psychology shows that human well-being suffers in windowless environments in many ways and a window view of nature is psychologically and physiologically beneficial to humans. Current window substitutes, still images and video, lack three dimensional properties necessary for a realistic viewing experience primarily motion parallax. We present a new system using a head-coupled display and image-based rendering to simulate a photorealistic artificial window view of nature with motion parallax. Evaluation data obtained from human subjects suggest that the system prototype is a better window substitute than a static image and has significantly more positive effects on observers moods. The test subjects judged the system prototype as a good simulation of, and acceptable replacement for, a real window, and accorded it much higher ratings for realism and preference than a static image

Physical performance and durability evaluation of rubberized concrete

The main objective of this research is to develop rubberized concrete with achievable structural strength using simple mix design. Simple mix design is a description by using the crumb rubber, used as in condition just received from the plant without any washing or pre-treating procedure. Then, three types of durability test were conducted namely, 1) Chloride ion diffusion test, 2) Abrasion wear resistance test, and 3) Freezing and thawing test. Up-to-date, many successful achievements were reported by researchers around the world. However, in Asian cases, very rare information on the use of wasted as a mixture component is gathered. By conducting this study, it could provide useful and valuable knowledge for construction technology especially for Asian industry. This dissertation consists mainly of the seven chapters. In Chapter 1, the background, problem statement, significance, research contribution and novelty of this study are listed out. In Chapter 2, research review on previous researchers work on the application of waste tire rubber in mortar/concrete and durability are described. Several important properties related to this study were viewed and discussed. High reduction in strength properties was observed by previous researchers and many suggestions were proposed either by washing the rubber or the use of suitable treatment on the rubber surface in order to enhance the bonding of the matrix. However, in my research, by using conventional mixing method, it was proposed that to use the rubber without any treatment (use directly as received) with maximum 20% sand replacement in volume is a method to use crumb rubber effectively. As a result, each rubberized mixture showed an acceptable structural strength value. In Chapter 3, three step-by-step stages of mix design were conducted and discussed. The first stage was the preliminary study to determine the suitable waste tire rubber size and percentage replacement that can be used in rubberized mortar. Three rubber size group were received from the industry plant which where combination of 1mm-3mm, combination of 0.71mm-1.7mm and 0.425mm. Size of 1mm – 3mm with 10% of sand replacement was chosen in terms of acceptable fresh and hardened mortar properties. In second stage, suitable water-to-cement ratio (w/c) and required additional binder was determined before proceeding to concrete mix. Results shows that w/c = 0.35 gave reliable mortar physical properties. Finally, rubberized concrete with w/c =0.35 was carried out and specimens were prepared for mechanical test and durability test. Along these three stages, air content was carefully studied and controlled. In Chapter 4, experimental work and discussion on chloride ion diffusion in rubberized concrete tested by migration test and by immersion in salt water was described. Effective diffusion coefficient, De test was conducted according to JSCE-G571-2003. Meanwhile, immersion test in salt water was conducted according to JSCE-G572-2003. Additional concrete specimen with w/c = 0.50 was prepared to study the effectiveness of CR in high w/c in comparison with w/c = 0.35. Results showed that chloride transport characteristics were improved by increasing the amount of CR due to the fact that CR has the ability to repel water. Meanwhile, rubberized concrete with w/c = 0.35 gave better resistance against chloride ion compared to w/c = 0.50. In Chapter 5, discussion on the effectiveness of crumb rubber to improve wear resistance tested by surface abrasion test was described. An experimental study on abrasion wear resistance was conducted on mortar (w/c = 0.35, 0.30 and 0.25) and concrete (w/c = 0.35) specimen containing CR with and without silica fume. From test results, it was clearly seen that 10% crumb rubber addition as sand replacement provide good resistance against abrasion. Meanwhile, compressive strength was the most important factor affecting the abrasion resistance, where abrasion resistance was increased with an increase in compressive strength. However, abrasion resistance was found to be slightly decreased when compressive strength exceeds 50N/mm2. In Chapter 6, the role of crumb rubber as air void under freezing and thawing was studied. Specimen was prepared in three groups; first group was the specimen without silica fume with air content ranging between 4% to 5%, second group was the specimen without silica fume with air content ranging between 0% to 1.5% and third group was the specimen with silica fume with air content ranging between 4% to 5%. These rubberized concrete were tested on freezing and thawing resistance to understand this behavior. The temperature for freezing and thawing was set to 15oC ±5oC for thawing temperature and -18oC ±5oC for freezing. This test was continued until 300 cycles according to ASTM C666. Results show that up to 300 freeze-thaw cycle, there was no minus effect observed for all specimen. In Chapter 7, conclusions are drawn based on Chapter 4 to Chapter 6 and recommendations for future works is presented

A methodology for the capture and analysis of hybrid data: a case study of program debugging

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The fast transient sky with Gaia

The ESA Gaia satellite scans the whole sky with a temporal sampling ranging from seconds and hours to months. Each time a source passes within the Gaia field of view, it moves over 10 CCDs in 45 s and a lightcurve with 4.5 s sampling (the crossing time per CCD) is registered. Given that the 4.5 s sampling represents a virtually unexplored parameter space in optical time domain astronomy, this data set potentially provides a unique opportunity to open up the fast transient sky. We present a method to start mining the wealth of information in the per CCD Gaia data. We perform extensive data filtering to eliminate known on-board and data processing artefacts, and present a statistical method to identify sources that show transient brightness variations on ~2 hours timescales. We illustrate that by using the Gaia photometric CCD measurements, we can detect transient brightness variations down to an amplitude of 0.3 mag on timescales ranging from 15 seconds to several hours. We search an area of ~23.5 square degrees on the sky, and find four strong candidate fast transients. Two candidates are tentatively classified as flares on M-dwarf stars, while one is probably a flare on a giant star and one potentially a flare on a solar type star. These classifications are based on archival data and the timescales involved. We argue that the method presented here can be added to the existing Gaia Science Alerts infrastructure for the near real-time public dissemination of fast transient events.Comment: 10 pages, 5 figures and 5 tables; MNRAS in pres

Searching for patterns in political event sequences: Experiments with the KEDs database

This paper presents an empirical study on the possibility of discovering interesting event sequences and sequential rules in a large database of international political events. A data mining algorithm first presented by Mannila and Toivonen (1996), has been implemented and extended, which is able to search for generalized episodes in such event databases. Experiments conducted with this algorithm on the Kansas Event Data System (KEDS) database, an event data set covering interactions between countries in the Persian Gulf region, are described. Some qualitative and quantitative results are reported, and experiences with strategies for reducing the problem complexity and focusing on the search on interesting subsets of events are described

Domestication, degeneration, and the establishment of the addo elephant national park in South Africa, 1910s-1930s

AbstractThis article examines conflict between farmers and elephants in the Addo region in 1910s–1930s South Africa to explore the porosity of the concepts ‘wild’, ‘tame’, and ‘domestic’, and their relationship to race, degeneration, nature conservation, and colonialism. In the 1910s, settler farmers indicted the ‘Addo Elephants’, as ‘vicious’ thieves who raided crops and ‘hunted’ farmers. This view conflicted with a widespread perception of elephants as docile, sagacious, and worthy of protection. Seeking to reconcile these views, bureaucrats were divided between exterminating the animals, creating a game reserve, and drawing upon the expertise of Indianmahoutsto domesticate them. Ultimately, all three options were attempted: the population was decimated by hunter Phillip Jacobus Pretorius, an elephant reserve was created, the animals were tamed to ‘lose their fear of man’ and fed oranges. Despite the presence of tame elephants and artificial feeding, the reserve was publicized as a natural habitat, and a window onto the prehistoric. This was not paradoxical but provokes a need to rethink the relationship between wildness, tameness, and domesticity. These concepts were not implicitly opposed but existed on a spectrum paralleling imperialist hierarchies of civilization, race, and evolution, upon which tame elephants could still be considered wild.</jats:p

Interactive data exploration with targeted projection pursuit

Data exploration is a vital, but little considered, part of the scientific process; but few visualisation tools can cope with truly complex data. Targeted Projection Pursuit (TPP) is an interactive data exploration technique that provides an intuitive and transparent interface for data exploration. A prototype has been evaluated quantitatively and found to outperform algorithmic techniques on standard visual analysis tasks

Asteroseismology of red giants: photometric observations of Arcturus by SMEI

We present new results on oscillations of the K1.5 III giant Arcturus (alpha Boo), from analysis of just over 2.5 yr of precise photometric observations made by the Solar Mass Ejection Imager (SMEI) on board the Coriolis satellite. A strong mode of oscillation is uncovered by the analysis, having frequency 3.51+/-0.03 micro-Hertz. By fitting its mode peak, we are able offer a highly constrained direct estimate of the damping time (tau = 24+/-1 days). The data also hint at the possible presence of several radial-mode overtones, and maybe some non-radial modes. We are also able to measure the properties of the granulation on the star, with the characteristic timescale for the granulation estimated to be 0.50+/-0.05 days.Comment: 6 pages, 5 figures; accepted for publication in MNRAS Letter