8,534 research outputs found
R.J. Sommers
No full textThe single-spaced paragraph on the “About the Author” page of R.J. Sommers’ latest novel says she lives in a one-story house on the edge of a city. It says she is renowned for writing relatable characters and compelling relationships. It says nothing about her own friends.
Gazing from a photo at the top of the page, R.J. Sommers appears to point a camera toward her readers..
A Multi-Sensor Fusion System for a Laboratory Based Autonomous Vehicle
No full textMotivated by the desire to generate richer descriptions of world state from disparate information sources the research area of Multi Sensor Data Fusion (MSDF) based upon a distributed Kalman Filter is addressed in this paper. To demonstrate the approach the MSDF system is applied i) in simulation to a second order plant and ii) to a laboratory based robot. MSDF research has demonstrated greater accuracy of state estimation which leads to greater system robustness with respect to sensor failure/sensor error. In addition the application of MSDF to systems with zero mean noise processes generates a Kalman filtered state estimate that is less sensitive to poor choices of system and process noise models
Author Co-Citation Analysis (ACA): a powerful tool for representing implicit knowledge of scholar knowledge workers
No full textIn the last decade, knowledge has emerged as one of the most important and valuable organizational assets. Gradually this importance caused to emergence of new discipline entitled ―knowledge management‖. However one of the major challenges of knowledge management is conversion implicit or tacit knowledge to explicit knowledge. Thus Making knowledge visible so that it can be better accessed, discussed, valued or generally managed is a long-standing objective in knowledge management. Accordingly in this paper author co- citation analysis (ACA) will be proposed as an efficient technique of knowledge visualization in academia (Scholar knowledge workers)
Finite element computation of attenuation in Bar-silencers and comparison with measured data
No full textA finite element formulation for sound attenuation in “bar-silencers”, consisting of rectangular prisms of sound-absorbing material placed in a rectangular lattice arrangement within a rigid-walled duct, is described. The presence of a uniform mean gas flow in the “airway” of the silencer is taken into account, as is anisotropy of the absorbent. Comparisons are made between experimental insertion less data and numerical predictions, and generally reasonable agreement is noted. Comparison is also made between the acoustic performance of bar-silencers and the equivalent splitter silencers, and it is shown that bar-silencers tend to have superior attenuation characteristics at low frequencies. The present results are discussed in the context of previously published work on bar-silencers.<br/
The effects of flanking transmission on sound attenuation in lined ducts
No full textIt is well known that flanking sound transmission can affect the acoustic attenuation in ducts lined with dissipative material. The exact nature of the flanking paths, “air-borne” (sometimes termed “radiation by-pass”) through “breakout” and subsequent “breakin” of sound through the duct walls, or “structure-borne” through axial transmission of weakly coupled (and lightly attenuated) structural/acoustic waves, is less well known. In this paper, an approximate analysis is presented for the case of a lined sheet metal duct located in a reverberant sound field. A Rayleigh-Ritz procedure is used to model the structural/acoustic modes propagating in the duct. The principle of reciprocity is then used to model the effects of breakin from the reverberant enclosure. Theoretical predictions of sound pressure on the duct axis are compared to experimental data for a typical air-moving duct, and the relative importance of the two flanking mechanisms is made clear.<br/
Precession- and Obliquity-Induced Changes in Moisture Sources for Enhanced Precipitation Over the Mediterranean Sea
No full textEnhanced winter precipitation over the Mediterranean Sea at times of minimum precession and maximum obliquity, that is, times of enhanced insolation seasonality, could provide freshwater required to form orbitally paced sedimentary cycles across the Mediterranean, offering a possible alternative to monsoonal runoff. We investigate the sources of the enhanced winter precipitation, by applying a moisture tracking model on the results of idealized orbital extreme experiments with a state-of-the-art climate model. Precession and obliquity enhance precipitation in fall and winter. Our study shows that the source of enhanced precipitation over the Mediterranean Sea differs during the winter half-year. In fall, the majority of the precession-induced precipitation increase originates from the Mediterranean itself. However, in late winter, the increase can be attributed to enhanced moisture advection from the Atlantic. This agrees with changes in evaporation and air-sea temperature differences over the Mediterranean. The obliquity-induced precipitation increase shows much less differences, with an equal contribution of local and Atlantic sources. The mechanism behind the Atlantic source of moisture, particularly important in late winter for precession-induced precipitation changes, is related to a weakened Azores High and slightly higher surface pressure over North Africa. The resulting anomalous circulation patterns generate enhanced Atlantic moisture transport toward the Mediterranean. These mechanisms coincide with weaker storm track activity over the North Atlantic, opposite to previous studies that often attribute enhanced Mediterranean winter precipitation to a southward shift and intensification of the Atlantic storm track. We thus provide an alternative mechanism for Atlantic sources of orbitally paced Mediterranean precipitation changes.Water Resource
Report on industrial attachment with R.J. Crocker Consultants Pte Ltd
No full textThis report documents the undertaking of the author’s six months of industrial attachment. It was the industrial attachment that gave him the opportunity to discover the innovative skills and expertise from his fellow colleagues working the organization. Throughout the attachment, the author had learnt a great deal from various trained and experienced engineers. He had been exposed to a variety of training namely (1) reinforcement concrete design, (2) steel and connection design, (3) modelling structures for design and analysis using software, (4) visual inspections for buildings, (5) preparing tender documents, (6) drawing, presentation and attending and (7) handling online submissions for building inspections, structural plans, design calculations, etc. Furthermore, by attending project meetings, preparing materials for presentations, tendering documents and drawings to privatized companies and public sectors all bestowed the author a concrete understanding of the type and quality of work required of and produced by a qualified engineer. Without the industrial attachment, all these practical skills and knowledge might not have been attainable by learning in the university alone. It was overall a fruitful experience
Exposure and vulnerability to climate extremes: population and assets exposure to coastal flooding in Dar es Salaam, Tanzania
No full textThe paper provides a first quantitative estimate of the potential number of people and value of assets exposed to coastal flooding in Dar es Salaam, Tanzania. The study used an elevation-based geographic information system-analysis based on physical exposure and socio-economic vulnerability under a range of climate and socio-economic scenarios. It particularly considered a worst-case scenario assuming even if defences (natural and/or man-made) exist, they are subjected to failure under a 100-year flood event. About 8% of Dar es Salaam lies within the low-elevation coastal zone (below the 10 m contour lines). Over 210,000 people could be exposed to a 100-year coastal flood event by 2070, up from 30,000 people in 2005. The asset that could be damaged due to such event is also estimated to rise from US35 million (2005) to US35million(2005)toUS10 billion (2070). Results show that socio-economic changes in terms of rapid population growth, urbanisation, economic growth, and their spatial distribution play a significant role over climate change in the overall increase in exposure. However, the study illustrates that steering development away from low-lying areas that are not (or less) threatened by sea-level rise and extreme climates could be an effective strategic response to reduce the future growth in exposure. Enforcement of such policy where informal settlements dominate urbanisation (as in many developing countries) could undoubtedly be a major issue. It should be recognised that this analysis only provides indicative results. Lack of sufficient and good quality observational local climate data (e.g. long-term sea-level measurements), finer-resolution spatial population and asset distribution and local elevation data, and detailed information about existing coastal defences and current protection levels are identified as limitations of the study. As such, it should be seen as a first step towards analysing these issues and needs to be followed by more detailed, city-based analyse
Information Circular 12. Selected Bibliography of Cuyuna Range Geology, Mining and Metallurgy
No full textThis work is an extension of a bibliography prepared by the author as part of a final report submitted to the U.S. Bureau of Mines for grant # G026/t002 entitled "Manganese-bearing ores of the Cuyuna iron range, east-central Minnesota, Phase 1". This bibliography, though directed primarily towards the geologic and mining literature of the Cuyuna range, does include the major works on the metallurgical aspects of the Cuyuna ores. For historical interest the very earliest publications are included. This list of abbreviations given on pages 2-4 are consistent with those from the "Bibliography and Index of Geology".Beltrame, R.J.. (1977). Information Circular 12. Selected Bibliography of Cuyuna Range Geology, Mining and Metallurgy. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/59304
- …
