321 research outputs found
Immigration social challenges in public spaces in Jeddah, Saudi Arabia
After the economic rise in Saudi Arabia in 1938, workers migrated from across Saudi Arabia seeking better work opportunities. Statistics from the General Census of Population and Housing in 2010 reveal that the total number of international immigrants increased from 0.7 to 1.73 million between 2002 and 2010 (from 29.4% to 50% of the Population), coming from different countries, cultural, social and religious backgrounds.
Over recent years, a perception has developed by some citizens that there are too many Immigrants, which has exposed increased feelings of insecurity. Anti-immigrant attitudes and social exclusion have become more prominent, Saudi nationals have become concerned about diminishing national identity, in addition to believe that expatriates take available work and economic opportunities away from nationals, main cause of crime, and moral corruption.
Immigrants have brought with them new ideas, skills and practices from their home cultures, which add to the new urban cultures in Jeddah. This has helped to create a culturally vibrant urban environment.
The study will discuss the challenges faced by immigrants in Jeddah, in terms of interaction and social harmony with Saudi citizens in public spaces, and the underlying causes of those challenges. Qualitative method is used in this study, through discuss and analyse general literature review about the objective of the research (Public space and Immigration social challenges in Jeddah), then propose general recommendations that contribute to the improvement of the immigrants social life in the public space
Synthetic aperture guided wave imaging using a mobile sensor platform
This oral session at conference looks at synthetic aperture guided wave imaging using a mobile sensor platfor
Novel algorithms for 3D surface point cloud boundary detection and edge reconstruction
Tessellated surfaces generated from point clouds typically show inaccurate and jagged boundaries. This can lead to tolerance errors and problems such as machine judder if the model is used for ongoing manufacturing applications. This paper introduces a novel boundary point detection algorithm and spatial FFT-based filtering approach, which together allow for direct generation of low noise tessellated surfaces from point cloud data, which are not based on pre-defined threshold values. Existing detection techniques are optimized to detect points belonging to sharp edges and creases. The new algorithm is targeted at the detection of boundary points and it is able to do this better than the existing methods. The FFT-based edge reconstruction eliminates the problem of defining a specific polynomial function order for optimum polynomial curve fitting. The algorithms were tested to analyse the results and measure the execution time for point clouds generated from laser scanned measurements on a turbofan engine turbine blade with varying numbers of member points. The reconstructed edges fit the boundary points with an improvement factor of 4.7 over a standard polynomial fitting approach. Furthermore, through adding artificial noise it has been demonstrated that the detection algorithm is very robust for out-of-plane noise lower than 25% of the cloud resolution and it can produce satisfactory results when the noise is lower than 75%
A noncontact ultrasonic platform for structural inspection
Miniature robotic vehicles are receiving increasing attention for use in nondestructive testing (NDE) due to their attractiveness in terms of cost, safety, and their accessibility to areas where manual inspection is not practical. Conventional ultrasonic inspection requires the provision of a suitable coupling liquid between the probe and the structure under test. This necessitates either an on board reservoir or umbilical providing a constant flow of coupling fluid, neither of which are practical for a fleet of miniature robotic inspection vehicles. Air-coupled ultrasound offers the possibility of couplant-free ultrasonic inspection. This paper describes the sensing methodology, hardware platform and algorithms used to integrate an air-coupled ultrasonic inspection payload into a miniature robotic vehicle platform. The work takes account of the robot's inherent positional uncertainty when constructing an image of the test specimen from aggregated sensor measurements. This paper concludes with the results of an automatic inspection of a aluminium sample
Should we be worried about the increasing foreign ownership of UK industries?
Should we be more concerned about the foreign ownership of UK Brands? Is Britain making the
most of its industrial brands? Much has been made of these questions and the recent contracting
out of nuclear energy to China. This is only one of several examples of recent contracting out of activity.
Indeed most rail franchises are now foreign owned and most electricity providers are also
from mainland Europe. The process of selling off much industry has been taking place in the UK
for many years and it has now gone much further than merely selling off the family silver. Recently
in the House of Commons mention was made of the time that has now arrived to sell the fixtures
and fittings. This paper sets out to explain the reasons why the UK has been willing to sell off many
historic firms and assesses the consequences of this for future generations. The paper draws on
theories of international marketing, corporate strategy and production to help explain the relevant
thinking behind current policies. It also draws on case examples, relevant theory and data, in
order to provide further evidence for future policy making, arguing that it still vitally important
for the UK to undertake the strategic stewardship of its remaining brands
Practical constraints on real time Bayesian filtering for NDE applications
An experimental evaluation of Bayesian positional filtering algorithms applied to mobile robots for Non-Destructive Evaluation is presented using multiple positional sensing data – a real time, on-robot implementation of an Extended Kalman and Particle filter was used to control a robot performing representative raster scanning of a sample. Both absolute and relative positioning were employed – the absolute being an indoor acoustic GPS system that required careful calibration. The performance of the tracking algorithms are compared in terms of computational cost and the accuracy of trajectory estimates. It is demonstrated that for real time NDE scanning, the Extended Kalman Filter is a more sensible choice given the high computational overhead for the Particle filter
Index based triangulation method for efficient generation of large three-dimensional ultrasonic C-scans
The demand for high speed ultrasonic scanning of large and complex components is driven by a desire to reduce production bottlenecks during the non-destructive evaluation of critical parts. Emerging systems (including robotic inspection) allow the collection of large data volumes in short time spans, compared to existing inspection systems. To maximize throughput, it is crucial that the reconstructed inspection data sets are generated and evaluated rapidly without a loss of detail. This requires new data visualization and analysis tools capable of mapping complex geometries whilst guaranteeing full part coverage. This paper presents an entirely new approach for the visualization of three-dimensional ultrasonic C-scans, suitable for application to high data throughput ultrasonic phased array inspection of large and complex parts. Existing reconstruction approaches are discussed and compared with the new Index Based Triangulation (IBT) method presented. The IBT method produces 3D C-scan representation, presented as coloured tessellated surfaces, and the approach is shown to work efficiently even on challenging geometry. An additional differentiating characteristic of the IBT method is that it allows easy detection of lack of coverage (an essential feature to ensure that inspection coverage can be guaranteed on critical components). Results demonstrate that the IBT C-scan generation approach runs over 60 times faster than a C-scan display based on Delaunay triangulation and over 500 times faster than surface reconstruction C-scans. In summary the main benefits of the new IBT technique are: • High speed generation of C-scans on large ultrasonic data sets (orders of magnitude improvement over surface reconstruction C-Scans) • Ability to operate efficiently on 3D mapped data sets (allowing 3D interpretation of C scans on complex geometry components) • Intrinsic indication of lack of inspection coverag
Development of a novel probe for remote visual inspection of pipework
The interior visual inspection of pipework is a critical inspection activity required to ensure the continued safe, reliable operation of plant and thus avoid costly outages. Typically, the video output from a manually deployed probe is viewed by an operator with the task of identifying and estimating the location of surface defects such as cracks, corrosion and pitting. However, it is very difficult to estimate the nature and spatial extent of defects from the often disorientating small field of view video of a relatively large structure. This paper describes the development of a new visual inspection system designed for inspecting 3 - 6 inch diameter pipes. The system uses a high resolution camera and structure from motion (SFM) algorithm to compute the trajectory of the probe through the pipe. In addition a laser profiler is used to measure the inner surface of the pipe and generate a meshed point cloud. The camera images are projected onto the mesh and the final output of the system is a photorealistic 3-D model of the internal surface of the pipework
The influence of the spatial distribution of 2D features on pose estimation for a visual pipe mapping sensor
This paper considers factors which influence the visual motion estimation of a sensor system designed for visually mapping the internal surface of pipework using omnidirectional lenses. In particular, a systematic investigation of the error caused by a non-uniform 2D spatial distribution of features on the resultant estimate of camera pose is presented. The effect of non-uniformity is known to cause issue and is commonly mitigated using techniques such as bucketing, however, a rigorous analysis of this problem has not been carried out in the literature. The pipe’s inner surface tend to be uniform and texture poor driving the need to understand and quantify the feature matching process. A simulation environment is described in which the investigation was conducted in a controlled manner. Pose error and uncertainty is considered as a function of the number of correspondences and feature coverage pattern in the form of contiguous and equiangular coverage around a circular image acquired by a fisheye lens. It is established that beyond 16 feature matches between the images, that coverage is the most influential variable, with the equiangular coverage pattern leading to a greater rate of reduction in pose error with increasing coverage. The application of the results of the simulation to a real world dataset are also provided
Machining-based coverage path planning for automated structural inspection
The automation of robotically delivered nondestructive evaluation inspection shares many aims with traditional manufacture machining. This paper presents a new hardware and software system for automated thickness mapping of large-scale areas, with multiple obstacles, by employing computer-aided drawing (CAD)/computer-aided manufacturing (CAM)-inspired path planning to implement control of a novel mobile robotic thickness mapping inspection vehicle. A custom postprocessor provides the necessary translation from CAM numeric code through robotic kinematic control to combine and automate the overall process. The generalized steps to implement this approach for any mobile robotic platform are presented herein and applied, in this instance, to a novel thickness mapping crawler. The inspection capabilities of the system were evaluated on an indoor mock-inspection scenario, within a motion tracking cell, to provide quantitative performance figures for positional accuracy. Multiple thickness defects simulating corrosion features on a steel sample plate were combined with obstacles to be avoided during the inspection. A minimum thickness mapping error of 0.21 mm and a mean path error of 4.41 mm were observed for a 2 m² carbon steel sample of 10-mm nominal thickness. The potential of this automated approach has benefits in terms of repeatability of area coverage, obstacle avoidance, and reduced path overlap, all of which directly lead to increased task efficiency and reduced inspection time of large structural assets
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