27 research outputs found
Instance Segmentation and 3D Multi-Object Tracking for Autonomous Driving
Autonomous driving promises to change the way we live. It could save lives, provide mobility, reduce wasted time driving, and enable new ways to design our cities. One crucial component in an autonomous driving system is perception, understanding the environment around the car to take proper driving commands. This dissertation focuses on two perception tasks: instance segmentation and 3D multi-object tracking (MOT).
In instance segmentation, we discuss different mask representations and propose representing the mask’s boundary as Fourier series. We show that this implicit representation is compact and fast and gives the highest mAP for a small number of parameters on the dataset MS COCO. Furthermore, during our work on instance segmentation, we found that the Fourier series is linked with the emerging field of implicit neural representations (INR). We show that the general form of the Fourier series is a Fourier-mapped perceptron with integer frequencies. As a result, we know that one perceptron is enough to represent any signal if the Fourier mapping matrix has enough frequencies. Furthermore, we used INR to represent masks in instance segmentation and got results better than the dominant grid mask representation.
In 3D MOT, we focus on tracklet management systems, classifying them into count-based and confidence-based systems. We found that the score update functions used previously for confidence-based systems are not optimal. Therefore, we propose better score update functions that give better score estimates. In addition, we used the same technique for the late fusion of object detectors. Finally, we tested our algorithm on the NuScenes and Waymo datasets, giving a consistent AMOTA boost
Practical Management of Diabetes during Ramadan Fast
Fasting in Ramadan is obligatory for all healthy Muslim adults. No food or drink may be consumed between dawn and sunset [1]. Strictly speaking, the fast of Ramadan is a period of “intermittent fasting” or daily cycles of “alternating” fasting and feeding periods. The periods of the fasting and feeding vary by the geographical locations and by time of the year. During the month of Ramadan, there are two main meals in most Moslem communities. These are commonly referred to by their Arabic origin, namely the “Iftar” (i.e. break of fast immediately after sunset) and “Sohur or Suhoor” (i.e. pre-dawn meal). As the Islamic calendar year is lunar, Ramadan (the ninth month) therefore starts approximately 10 days earlier each year on the Gregorian calendar. This year, 2007, Ramadan is likely to start between 12th and 14th September
The utility of chest ultrasound-guided fine-needle biopsy in the diagnosis of plasmacytoma
Background. Plasmacytoma is a plasma cell dyscrasia originating from a single clone of plasma cells of B-lymphocyte lineage and produces a monoclonal immunoglobulin. Transthoracic fine-needle aspiration (TTNA) under ultrasound (US) guidance is a well-validated technique for the diagnosis of many neoplasms and has been shown to be safe and cost effective, with diagnostic yields comparable to more invasive techniques. However, the role of TTNA in the diagnosis of thoracic plasmacytoma is not well established.
Objective. The aim of this study was to assess the utility of TTNA and cytology in confirming a diagnosis of plasmacytoma.
Methods. All cases of plasmacytoma diagnosed from January 2006 to December 2017 by the Division of Pulmonology, Tygerberg Hospital, were retrospectively identified. All patients who underwent an US-guided TTNA and of whose clinical records could be retrieved were included in this cohort. The International Myeloma Working Group’s definition of a plasmacytoma was used as the gold standard. Results. A total of 12 cases of plasmacytoma were identified and 11 patients included (one patient was excluded owing to missing medical records). Six of the 11 patients (mean age 59.5 ± 8.5 years) were male. Radiologically, most had multiple lesions (n=7), most commonly bony (n=6) with vertebral body involvement (n=5) and pleural-based lesions (n=2). Rapid onsite evaluation (ROSE) was performed and documented in 6 of the 11 cases, and a provisional diagnosis of plasmacytoma was suggested in 5 of the 6 patients (83.3%). The final laboratory cytological diagnoses of all 11 cases were compatible with plasmacytoma which was further confirmed via a bone marrow biopsy (n=4) and by serum electrophoresis (n=7).
Conclusion. US-guided fine-needle aspiration is feasible and is useful to confirm a diagnosis of plasmacytoma. Its minimally invasive nature may be the ideal investigation of choice in suspected cases
Diabesity in the Arabian Gulf: Challenges and Opportunities
Diabesity (diabetes associated with obesity) is a major global and local public health concern, which has almost reached an epidemic order of magnitude in the countries of the Arabian Gulf and worldwide. We sought to review the lifestyle trends in this region and to highlight the challenges and opportunities that health care professionals face and attempt to address and correct them. In this regard, we aimed to review the regional data and widely held expert opinions in the Arabian Gulf and provide a thematic review of the size of the problem of diabesity and its risk factors, challenges, and opportunities. We also wished to delineate the barriers to health promotion, disease prevention, and identify social customs contributing to these challenges. Lastly, we wished to address specific problems with particular relevance to the region such as minimal exercise and unhealthy nutrition, concerns during pregnancy, the subject of childhood obesity, the impact of Ramadan fasting, and the expanding role of bariatric surgery. Finally, general recommendations for prevention, evidence-based, and culturally competent management strategies are presented to be considered at the levels of the individual, community, and policymakers
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Aspects of aquifer test error analysis
In aquifer test analysis the basic sources of errors are in measurement, wrong models, and in the estimation methods. Each is characterized and analyzed statistically. The estimation error was determined for graphical fitting by a panel of hydrologists. For automatic fitting the estimation error was obtained by use of nonlinear regression theory. First order analysis is employed to determine the effect of these errors on predictions utilizing the estimated parameters. Regression theory is further utilized to predetermine the efficiency of an aquifer test design (the variability of the resulting estimates) from the C matrix. There is sufficient similarity between graphical and automatic fitting to believe that the conclusions determined for automatic fitting will qualitatively hold when the fitting method is graphical.hydrology collectio
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Aspects of Aquifer Test Error Analysis
From the Proceedings of the 1981 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona - Nevada Academy of Science - May 1-2, 1981, Tucson, ArizonaErrors in the estimation of the aquifer parameters T and S derived from aquifer test data are examined as to their cause and effects. The analysis is based on the Theis equation. The basic causes of error are in the measurements of drawdown and pumping rate, in fitting the model to the data and in violations of model assumptions. Measurement errors were studied experimentally. Curve fittings by hydrologists were compared to "automatic" curve fittings obtained by nonlinear regression. The covariance matrix of T and S obtained in this manner was used, in conjunction with sensitivity analysis, to estimate the error in prediction of future drawdown. While automatic fitting is not a perfect substitute for graphical fitting, there is a definite relation between the two methods which allows the use of the statistics developed by nonlinear regression theory to be used to study the cause, effects and risks inherent in aquifer analysis.This article is part of the Hydrology and Water Resources in Arizona and the Southwest collections. Digital access to this material is made possible by the Arizona-Nevada Academy of Science and the University of Arizona Libraries. For more information about items in this collection, contact [email protected]