Real-Time Dense Stereo Matching With ELAS on FPGA Accelerated Embedded Devices

For many applications in low-power real-time robotics, stereo cameras are the sensors of choice for depth perception as they are typically cheaper and more versatile than their active counterparts. Their biggest drawback, however, is that they do not directly sense depth maps; instead, these must be estimated through data-intensive processes. Therefore, appropriate algorithm selection plays an important role in achieving the desired performance characteristics. Motivated by applications in space and mobile robotics, we implement and evaluate a FPGA-accelerated adaptation of the ELAS algorithm. Despite offering one of the best trade-offs between efficiency and accuracy, ELAS has only been shown to run at 1.5-3 fps on a high-end CPU. Our system preserves all intriguing properties of the original algorithm, such as the slanted plane priors, but can achieve a frame rate of 47fps whilst consuming under 4W of power. Unlike previous FPGA based designs, we take advantage of both components on the CPU/FPGA System-on-Chip to showcase the strategy necessary to accelerate more complex and computationally diverse algorithms for such low power, real-time systems.Comment: 8 pages, 7 figures, 2 table

Misrepresentation, Manipulation, and Misunderstandings: The Early Jesuit Mission to China 1580-1610

The early Jesuit mission to China is widely acknowledged as a fusion of two fundamentally different cultures interacting on an equal basis and sharing knowledge about science, religion and the world. The historiography around the mission has already widely examined the misunderstandings that occurred between the cultures. However, a re-examination of the frequently applied label, a 'policy of accommodation', highlights other interpretations. By applying theories on early modern dissimulation, as well as close analysis of Matteo Ricci's The True Meaning of the Lord of Heaven and his map of the world, this dissertation concludes that the mission was founded on the rigid control of information and careful selection of which aspects of Western knowledge, geography and religion were to be presented. Evidence presented suggests that the Jesuits, using elements of the practice of dissimulation, concealed certain aspects of themselves and their true aims from the Chinese. Furthermore, they exploited material exchange to ingratiate themselves with the upper echelons of Chinese society. This dissertation argues that Matteo Ricci, whilst demonstrating European cartography and mathematics in his map, distorted certain areas of the map to increase the perceived distance between Europe and China, and also misrepresented the political reality of Europe. The Jesuits' teaching style and method of recruitment of converts was one of esoteric teachings. They withheld information about Christianity, which they knew would not be well received, and only passed knowledge of the mysteries of the Christian faith to those Chinese who had already converted. It can be concluded that the Jesuits operating in China were highly perceptive as to the image of Christianity and Europe they were presenting, and it was with propaganda and the control of information that they sought to cement their position in Chinese society

The History of Star Forming Galaxies and their Environment as seen by Spitzer: A Review

The advent of the Spitzer Space Telescope has revolutionized our understanding of the history of star formation and galaxy mass assembly in the Universe. The tremendous leap in sensitivity from previous mid-to-far IR missions has allowed Spitzer to perform deeper, and wider, surveys than previously possible at these wavelengths. In this brief review I highlight some of the key results to come out of these surveys, and the implications these have for current models of galaxy formation and evolution.Comment: 9 pages, 3 figures, invited review, to be published in the proceedings of the conference "AKARI, a light to illuminate the misty Universe", University of Tokyo, Japan, 16-19 February 200

Comparative study of selected indoor concentration from selective laser sintering process using virgin and recycled polyamide nylon (pa12)

Additive manufacturing (AM) stands out as one of the promising technologies that have huge potential towards manufacturing industry. The study on additive manufacturing impact on the environment and occupational exposure are attracting growing attention recently. However, most of the researcher focus on desktop and fused deposition modelling type and less attention given to the industrial type of AM. Usually, during the selective laser sintering process, recycle powder will be used again to reduce cost and waste. This article compares the PM 2.5, carbon dioxide (CO2) and total volatile organic compound (TVOC) concentration between virgin and recycles powder using polyamide-nylon (PA12) towards indoor concentration. Four phases of sampling involve during air sampling accordingly to the Industry Code of Practice on Indoor Air Quality 2010 by DOSH Malaysia. It was found that PM 2.5 and CO2 concentration are mainly generated during the pre-printing process. The recycle powder tended to appear higher compared to virgin powder in terms of PM 2.5, and CO2. The peak value of PM 2.5 is 1452 μg/m3 and CO2 is 1218 ppm are obtained during the pre-printing process during 8 hours of sampling. TVOC concentration from recycling powder is slightly higher during the post- printing phase where confirm the influence of the powder cake and PA12 temperature from the printing process. In summary, this work proves that elective laser sintering (SLS) machine operators are exposed to a significant amount of exposure during the SLS printing process. Mitigation strategies and personal protective equipment are suggested to reduce occupational exposure

Diametral compression test method to analyse relative surface stresses in thermally sprayed coated and uncoated circular disc specimens.

In firsts of its investigation, a diametral compression destructive testing method (also known as Brazilian test) was performed on thermally sprayed coated and uncoated circular disc specimens to compare relative surface stresses. The coating investigated had about 250 μm thickness deposited on 4.76 mm thick Hastelloy®X substrate discs of 20 mm diameter. In the instrumented experiment (diametral compression test) strain gauge rosettes were used to measure strains on two circular surfaces of disc specimen (coated and uncoated sides) and converted to stress values for analysis. Where comparisons were made, the experimental and finite element simulation results were in some agreement with overall understanding of the diametral compression testing behaviour. For coated specimen, test results convey that higher stresses exist within the uncoated side of the specimen rather than the coated side. Although the methods proposed would be deemed most comparable to real life scenarios (e.g. to quantify coating delamination strength and failure mechanics), this type of experimental investigation has certain advantages and limitations

Food chain inefficiency (FCI) : accounting conversion efficiencies across entire food supply chains to re-define food loss and waste

Achieving global food security requires a new approach that integrates not only all aspects of the growing, harvesting and processing of food (necessary to ensure sufficient affordable and sustainable production to alleviate hunger) but also the complexities associated with food consumption including deterring unhealthy overconsumption. Inefficiencies occur at various points along the agri-food supply chain but at present they are inadequately conceptualized via separate accounts of food loss, food waste, supply chain management, and public health. Here we re-define food loss and waste through the concept of conversion efficiency applied to the entire system, an approach up to now only applied to the primary processes of crop productivity. Nine conversion efficiencies are defined: sunlight capture efficiency; photosynthesis use efficiency; biomass allocation efficiency; harvesting efficiency; storage and distribution efficiency; processing efficiency; retailing efficiency; consumption efficiency; and dietary efficiency. Using the production and consumption of bread in the UK as an example, we demonstrate how efficiencies may be estimated and thus where the main inefficiencies lie, so indicating where the most significant improvements could be made. We suggest that our approach, which introduces the term Food Chain Inefficiency (FCI) to re-define food loss and waste, provides a rational and effective way to devise the practical interventions and policies needed to deliver a sustainable agri-food system

Technology-assisted stroke rehabilitation in Mexico: a pilot randomized trial comparing traditional therapy to circuit training in a Robot/technology-assisted therapy gym

Background Stroke rehabilitation in low- and middle-income countries, such as Mexico, is often hampered by lack of clinical resources and funding. To provide a cost-effective solution for comprehensive post-stroke rehabilitation that can alleviate the need for one-on-one physical or occupational therapy, in lower and upper extremities, we proposed and implemented a technology-assisted rehabilitation gymnasium in Chihuahua, Mexico. The Gymnasium for Robotic Rehabilitation (Robot Gym) consisted of low- and high-tech systems for upper and lower limb rehabilitation. Our hypothesis is that the Robot Gym can provide a cost- and labor-efficient alternative for post-stroke rehabilitation, while being more or as effective as traditional physical and occupational therapy approaches. Methods A typical group of stroke patients was randomly allocated to an intervention (n = 10) or a control group (n = 10). The intervention group received rehabilitation using the devices in the Robot Gym, whereas the control group (n = 10) received time-matched standard care. All of the study subjects were subjected to 24 two-hour therapy sessions over a period of 6 to 8 weeks. Several clinical assessments tests for upper and lower extremities were used to evaluate motor function pre- and post-intervention. A cost analysis was done to compare the cost effectiveness for both therapies. Results No significant differences were observed when comparing the results of the pre-intervention Mini-mental, Brunnstrom Test, and Geriatric Depression Scale Test, showing that both groups were functionally similar prior to the intervention. Although, both training groups were functionally equivalent, they had a significant age difference. The results of all of the upper extremity tests showed an improvement in function in both groups with no statistically significant differences between the groups. The Fugl-Meyer and the 10 Meters Walk lower extremity tests showed greater improvement in the intervention group compared to the control group. On the Time Up and Go Test, no statistically significant differences were observed pre- and post-intervention when comparing the control and the intervention groups. For the 6 Minute Walk Test, both groups presented a statistically significant difference pre- and post-intervention, showing progress in their performance. The robot gym therapy was more cost-effective than the traditional one-to-one therapy used during this study in that it enabled therapist to train up to 1.5 to 6 times more patients for the approximately same cost in the long term. Conclusions The results of this study showed that the patients that received therapy using the Robot Gym had enhanced functionality in the upper extremity tests similar to patients in the control group. In the lower extremity tests, the intervention patients showed more improvement than those subjected to traditional therapy. These results support that the Robot Gym can be as effective as traditional therapy for stroke patients, presenting a more cost- and labor-efficient option for countries with scarce clinical resources and funding. Trial registration ISRCTN98578807