How smart is institutional trading?

Ministry of Education, Singapore under its Academic Research Funding Tier 1; Lee Kong Chian Fund for Excellenc

A Study on Robot and Drone Assisted Delivery Problems and Their Solutions

The surge in online retail, driven by population growth, technology, and the Covid-19 pandemic, emphasizes the need for efficient last-mile delivery. This thesis explores Robot and Drone-Assisted Delivery Problems, addressing the need for innovative solutions in the integration of trucks and delivery robots or drones. Recent technological advancements allow drones to be launched or collected from moving vehicles without human intervention, challenging the common notion of restricting these actions to when the truck is stationary. Chapter 3 of this thesis introduces the Covering Salesman Problem with Nodes and Segments Using Drones (CSPNS-D), a problem whose approach determines the maximum coverage area of nodes or links serviced by a drone as the truck traverses the corresponding node or link. Three Mixed Integer Linear Programming (MILP) models, representing various drone coverage areas, were proposed to minimize the truck's working span. Results demonstrate optimal solutions for up to 35 customers, with substantial savings compared to the Traveling Salesman Problem (TSP). Additionally, a computationally efficient link removal heuristic is presented for larger instances. Chapter 4 introduces the Robot-Assisted Delivery Problem (RADP), integrating trucks, robots, and local depots. Two consistent MILP models, RADP-1 and RADP-2, optimize delivery schedules, with RADP-1 proving more efficient due to a large number of feasible operations in RADP-2. RADP-1 considers each arc and node separately in the modelling process, whereas RADP-2 treats combinations of arcs and nodes as a single operation. Unlike the CSPNS-D models, RADP only allows launching and collection of robots when the truck is stationary. RADP models, like CSPNS-D, pose NP-hard challenges, necessitating heuristic approaches for larger problems. The proposed P-Heur and K-Heur heuristics prioritize operations based on the node-time ratio and employ a K-Means algorithm for cluster decomposition and MILP solution, respectively, effectively addressing larger-scale challenges

1st Place Solution to MultiEarth 2023 Challenge on Multimodal SAR-to-EO Image Translation

The Multimodal Learning for Earth and Environment Workshop (MultiEarth 2023) aims to harness the substantial amount of remote sensing data gathered over extensive periods for the monitoring and analysis of Earth's ecosystems'health. The subtask, Multimodal SAR-to-EO Image Translation, involves the use of robust SAR data, even under adverse weather and lighting conditions, transforming it into high-quality, clear, and visually appealing EO data. In the context of the SAR2EO task, the presence of clouds or obstructions in EO data can potentially pose a challenge. To address this issue, we propose the Clean Collector Algorithm (CCA), designed to take full advantage of this cloudless SAR data and eliminate factors that may hinder the data learning process. Subsequently, we applied pix2pixHD for the SAR-to-EO translation and Restormer for image enhancement. In the final evaluation, the team 'CDRL' achieved an MAE of 0.07313, securing the top rank on the leaderboard

Effect of Vitamin D supplementation in under-5 children with pneumonia: A randomized controlled trial

Objective: The objective of the study was to study whether Vitamin D supplementation in under-5 children presenting with pneumonia and severe pneumonia reduces its duration and recurrences. Study Design: This study was designed as a double-blind, randomized, placebo-controlled trial. Setting: Pediatric unit of a teaching institute. Methods: A total of 80 children aged between 2 months and 5 years with the diagnosis of pneumonia and severe pneumonia (as per the WHO definition) admitted over a period of 1 year were included in the study. Children with features of rickets, severe malnutrition, asthma, any underlying medical disorders, and if received Vitamin D supplementation over the past 12 months were excluded from the study. Children were randomized into two groups. Intervention group received 300,000 IU (international units) of Vitamin D (1 ml), and the control group received 1 ml of sterile water as a placebo along with antibiotics and supportive care. Children were monitored for the resolution of symptoms. The two groups were comparable for baseline demographic, socioeconomic, clinical, and laboratory parameters. All the children were followed up for 3 months after discharge for any repeat episodes of pneumonia. Results: Time to resolution of symptoms (fever, tachypnea, and chest retractions) was not significant (3.6

The Effect of Rainfall on Aggregate Stability and Splash Erosion on Some Agricultural Soils of Borno State, Nigeria

The amount of splash and aggregate stability of some agricultural soils were investigated with respect to rainfall duration. The soil samples were graded in aggregate sizes of 2.36, 3.35 and 6.70 mm, respectively. Energy in the form of water drops (3 mm diameter) falling from a height of 2.65 m was applied, using rainfall simulators with rainfall intensity of 228.6 m/hr at an interval of 5 min. The amount of splash was found to vary for clay soil from 3.06 to 4.46 g/cm (2.36 mm), 4.08 to 5.38 g/cm2 (3.35 mm), and 6.03 to 7.43 g/cm 2 (6.70 mm), while for sandy clay, it varies from 2.72 to 4.02 g/cm2 (2.36 mm), 3.09 to 4.48 g/cm 2 (3.35 mm) and 5.06 to 6.62 g/cm2 (6.70 mm), respectively. Aggregate stability was found to vary for clay at 11.02% moisture content from 4.44 to 3.04% (2.36 mm), 3.42 to 2.12%. (3.35 mm) and 1.47 to 0.07% (6.70 mm), while it varies for sandy clay at 10.68% moisture content from 4.78 to 3.48% (2.3 mm), 4.41 to 3.02% (3.35 mm) and 2.44 to 0.88% (6.70 mm), respectively

Mechanism of worsening diabetic retinopathy with rapid lowering of blood glucose: the synergistic hypothesis

Insulin treatment has been associated with a paradoxical worsening of diabetes retinopathy since many years in European cohorts. Recently, this issue has been stressed by some studies conducted in other parts of the world. However, the mechanism underlying such evolution is not well understood. An osmotic theory has been evocated but failed to explain the clinical features of the disease. Considering recent findings from basic and clinical research, we discuss the possibility of a synergistic hypothesis based on the simultaneous action of insulin and vascular endothelial growth factor on eye blood vessels. We postulate that exogenous insulin could act synergistically with the vascular endothelial growth factor expressed by ischemic retina so as to trigger vascular proliferation and the worsening of diabetes retinopathy

Prevalence, infectivity and correlates of hepatitis B virus infection among pregnant women in a rural district of the Far North Region of Cameroon

BACKGROUND:Epidemiological data on hepatitis B virus (HBV) infection among pregnant women in Cameroon are very scarce, especially in the rural milieu. The purpose of this study was to determine the prevalence and factors associated with HBV infection, and the infectivity of rural pregnant women in the Far North Region of Cameroon. METHODS: A cross-sectional study was conducted in three rural health facilities of the Guidiguis health district between December 2013 and March 2014. We consecutively recruited 325 pregnant women attending antenatal consultations. A pretested questionnaire was used to collect socio-demographic data and factors associated with HBV infection. The presence of hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg) and human immunodeficiency virus (HIV) were determined using commercial test strips. Regression analyses were used to assess correlates of HBV infection. RESULTS: The mean age was 24.4 (SD5.6) years. Most women were married (97.2%) and housewives (96.4%), with less than secondary education level (80%). Only 4 women (1.2%) had been vaccinated against HBV. Thirty-three women (10.2%) were HBsAg-positive, of whom 4 (12.1%) were positive to HBeAg. The prevalence of HIV infection was 2.5% (8/325). Overall, 5 (1.5%) women were co-infected with HIV and HBV. Independent correlates of HBV infection included history of blood transfusion (adjusted odd ratio 12.59, 95% CI 1.46-108.89; p=0.021) and concurrent infection by HIV (adjusted odd ratio 22.53, 95% CI 4.76-106.71; p<0.0001). CONCLUSION: The prevalence of HBV infection among pregnant women in this rural milieu is high. History of blood transfusion and HIV infection are highly associated with HBV infection. The relative low rate of women positive to both HBsAg and HBeAg suggests that perinatal transmission of HBV might not be the prevailing mode of HBV transmission in this area