DET: Data Enhancement Technique for Aerial Images

Deep learning and computer vision are two thriving research areas within machine learning. In recent years, as the available computing power has grown, it has led to the possibility of combining the approaches, achieving state-of-the-art results. An area of research that has greatly benefited from this development is building detection. Although the algorithms produce satisfactory results, there are still many limitations. One significant problem is the quality and edge sharpness of the segmentation masks, which are not up to the standard required by the mapping industry. The predicted mask boundaries need to be sharper and more precise to have practical use in map production. This thesis introduces a novel Data Enhancement Technique (DET) to improve the boundary quality of segmentation masks. DET has two approaches, Seg-DET, which uses a segmentation network, and Edge-DET, which uses an edge-detection network. Both techniques highlight buildings, creating a better input foundation for a secondary segmentation model. Additionally, we introduce ABL(RMI), a new compounding loss consisting of Region Mutual Information Loss (RMI), Lovasz-Softmax Loss (Lovasz), and Active Boundary Loss (ABL). The combination of loss functions in ABL(RMI) is optimized to enhance and improve mask boundaries. This thesis empirically shows that DET can successfully improve segmentation boundaries, but the practical results suggest that further refinement is needed. Additionally, the results show improvements when using the new compounding loss ABL(RMI) compared to its predecessor, ABL(CE) which substitutes RMI with Cross-Entropy loss(CE)

Vertical small scale variations of sorption and mineralization of three herbicides in subsurface limestone and sandy aquifer

International audienceVertical variation in sorption and mineralization potential of mecoprop (MCPP), isoproturon and acetochlor were investigated at low concentrations (μg-range) at the cm-scale in unsaturated sub-surface limestone samples and saturated sandy aquifer samples from an agricultural catchment in Brévilles, France. From two intact core drills, four heterogenic limestone sections were collected from 4.50 to 26.40 m below surface (mbs) and divided into 12 sub-samples of 8-25 cm length, and one sandy aquifer section from 19.20 to 19.53 m depth divided into 7 sub-samples of 4-5 cm length. In the sandy aquifer section acetochlor and isoproturon sorption increased substantially with depth; in average 78% (acetochlor) and 61% (isoproturon) per 5 cm. Also the number of acetochlor and isoproturon degraders (most-probable-number) was higher in the bottom half of the aquifer section (93-> 16 000/g) than in the upper half (4-71/g). One 50 cm long limestone section with a distinct shift in color showed a clear shift in mineralization, number of degraders and sorption: In the two brown, uppermost samples, up to 31% mecoprop and up to 9% isoproturon was mineralized during 231 days, the numbers of mecoprop and isoproturon degraders were 1300 to > 16 000/g, and the sorption of both isoproturon and acetochlor was more than three times higher, compared to the two deeper, grayish samples just below where mineralization (≤ 4%) and numbers of degraders (1-520/g) were low for all three herbicides. In both unsaturated limestone and sandy aquifer, variations and even distinct shifts in both mineralization, number of specific degraders and sorption were seen within just 4-15 cm of vertical distance. A simple conceptual model of herbicides leaching to groundwater through a 10 m unsaturated limestone was established, and calculations showed that a 30 cm active layer with the measured sorption and mineralization values hardly impacted the fate of the investigated herbicides, whereas a total thickness of layers of 1 m would substantially increase natural attenuation

The effect of preoperative methylprednisolone on pulmonary function and pain after lung operations

AbstractThirty-six patients undergoing elective thoracotomy with pulmonary resection with the use of combined epidural and general anesthesia were randomized into a double-blind study to receive a single intravenous preoperative dose of methylprednisolone 25 mg/kg body weight or a placebo (saline solution). Postoperative pain relief consisted of epidural morphine 4 mg and paracetamol 1 gm three times a day for 4 days. Postoperative pulmonary function (peak expiratory flow rate, forced expiratory volume in first second, forced vital capacity) was evaluated on days 1, 2, 3, 4, and 7 and after 1 month. The value obtained after 1 month served as the control value. Pain score at rest and during cough was evaluated after 4 and 8 hours and on days 1, 2, 3, and 4. Pulmonary function was reduced after operation to the same degree in the steroid and placebo group: 42% versus 41% for forced expiratory volume in first second and 38% versus 39% for forced vital capacity, compared with control values after 1 month. Pain score was reduced in the steroid group after 4 hours and on day 1 during rest and after 4 and 8 hours and on day 2 during cough, compared with results in the placebo group ( p < 0.05). In the steroid group three patients underwent reoperation because of leakage through the chest wall incision. In conclusion, administration of a single preoperative dose of methylprednisolone did not affect the postoperative reduction in pulmonary function after thoracotomy despite attenuated pain response, and the results do not warrant steroid administration before lung operation. (J Thorac Cardiovasc Surg 1996;112:142-5

Tumor volume and cancer stem cell expression as prognostic markers for high-dose loco-regional failure in head and neck squamous cell carcinoma - A DAHANCA 19 study

BACKGROUND AND PURPOSE: Reliable and accessible biomarkers for patients with Head and Neck Squamous Cell Carcinoma (HNSCC) are warranted for biologically driven radiotherapy (RT). This study aimed to investigate the prognostic value of putative cancer stem cell (CSC) markers, hypoxia, and tumor volume using loco-regional high-dose failure (HDF) as endpoint.MATERIALS AND METHODS: Tumor tissue was retrieved from patients treated with primary chemo-(C-)RT and nimorazole for HNSCC in the Danish Head and Neck Cancer Study Group (DAHANCA) 19 study. Tumor volume, hypoxic classification, and expression of CSC markers CD44, SLC3A2, and MET were analyzed. For patients with eligible data on all parameters (n = 340), the risk of HDF following primary chemo-(C-)RT were analyzed by these biomarkers as a whole and stratified for p16-positive oropharynx (p16 + OPSCC) vs p16-negative (p16-) tumors (oral cavity, p16- oropharynx, hypopharynx and larynx).RESULTS: Higher risk of HDF was seen for patients with larger primary and nodal volume (&gt;25 cm3, Hazard Ratio (HR): 3.00 [95 % CI: 1.73-5.18]), high SLC3A2 (HR: 2.99 [1.28-6.99]), CD44 (&gt;30 % positive, HR: 2.29 [1.05-5.00]), and p16- tumors (HR: 2.53 [1.05-6.11]). p16- tumors had a higher CSC marker expression than p16 + OPSCC. The factors associated with the highest risk of HDF were larger volume (HR: 3.29 [1.79-6.04]) for p16- tumors (n = 178) and high SLC3A2 (HR: 6.19 [1.58-24.23]) for p16 + OPSCC (n = 162).CONCLUSION: Tumor volume, p16, and CSC markers are potential biomarkers for HDF for patients with HNSCC treated with (C-)RT. Lower expression of CSC in p16 + OPSCC may contribute to better tumor control.</p

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements