Investigation into Unmanned Aircraft System Incidents in the National Airspace System

With the promulgation of Federal Aviation Regulations for small unmanned aircraft systems, the volume of unmanned flight operations is expected to increase, which demands an analysis of potential hazards to the National Airspace System. Descriptive statistics were used to investigate reports archived in the Aviation Safety Information and Analysis and Sharing system involving unmanned aircraft systems, as well as the FAA UAS Sightings Reports database. The frequency of reports involving airspace violations, and Near Mid-air Collisions by unmanned aircraft systems as well as an analysis of the location, sponsor category, phase of flight, altitude, and airspace type in which the incident occurred were investigated. An upward trend was observed in the number of events with 2015 showing the highest frequency. Most events took place in California and New York and often transpired in Class B Airspaces. The cruise and approach to landing portions of the flight envelope account for the highest number of UAS-related events. A majority of reported events took place between 1000 feet and 2000 feet above the ground and were academic institution sponsored activity. Additionally, the majority of events involved conflicts with commercial manned aircraft transporting passengers

Improving Cloud Middlebox Infrastructure for Online Services

Middleboxes are an indispensable part of the datacenter networks that provide high availability, scalability and performance to the online services. Using load balancer as an example, this thesis shows that the prevalent scale-out middlebox designs using commodity servers are plagued with three fundamental problems: (1) The server-based layer-4 middleboxes are costly and inflate round-trip-time as much as 2x by processing the packets in software. (2) The middlebox instances cause traffic detouring en route from sources to destinations, which inflates network bandwidth usage by as much as 3.2x and can cause transient congestion. (3) Additionally, existing cloud providers do not support layer-7 middleboxes as a service, and third-party proxy-based layer-7 middlebox design exhibits poor availability as TCP state stored locally on middlebox instances are lost upon instance failure. This thesis examines the root causes of the above problems and proposes new cloud-scale middlebox design principles that systemically address all three problems. First, to address the performance problem, we make a key observation that existing commodity switches have resources available to implement key layer-4 middlebox functionalities such as load balancer, and by processing packets in hardware, switches offer low latency and high capacity benefits, at no additional cost as the switch resources are idle. Motivated by this observation, we propose the design principle of using idle switch resources to accelerate middlebox functionailites. To demonstrate the principle, we developed the complete L4 load balancer design that uses commodity switches for low cost and high performance, and carefully fuses a few software load balancer instances to provide for high availability. Second, to address the high network overhead problem from traffic detouring through middlebox instances, we propose to exploit the principles of locality and flexibility in placing the middlebox instances and servers to handle the traffic closer to the sources and reduce the overall traffic and link utilization in the network. Third, to provide high availability in a layer 7 middleboxes, we propose a novel middlebox design principle of decoupling the TCP state from middlebox instances and storing it in persistent key-value store so that any middlebox instance can seamlessly take over any TCP connection when middlebox instances fail. We demonstrate the effectiveness of the above cloud-scale middlebox design principles using load balancers as an example. Specifically, we have prototyped the three design principles in three cloud-scale load balancers: Duet, Rubik, and Yoda, respectively. Our evaluation using a datacenter testbed and large scale simulations show that Duet lowers the costs by 12x and latency overhead by 1000x, Rubik further lowers the datacenter network traffic overhead by 3x, and Yoda L7 Load balancer-as-a-service is practical; decoupling TCP state from load balancer instances has a negligible

Design Optimization of Single Overhead Crain Girder using Finite Element Analysis

This study aims to develop strategies in the field of structural optimization and implement these strategies into the design processes. The single-sided swing arm has been selected as the subject of this study. The primary objective of this project is to reduce the mass of an existing steel girder arm, a component of a 1-ton capacity overhead crane, through the application of topology optimization techniques. This weight reduction is essential to enhance cost-effectiveness and operational performance. To achieve this goal, the Finite Element software Ansys, equipped with multiple modules, has been utilized. Ansys is responsible for preparing the finite element model and conducting modal and static analyses. Topology optimization is performed using Inspire. Static analysis is carried out, considering the effective dynamic load on the crane girder in accordance with IS codes. The optimization method applied in this study has successfully resulted in an 18.97% reduction in the mass of the existing girder. &nbsp

A Clinical Profile of 50 cases of Hypoglycemia in a Tertiary Care Hospital

Hypoglycemia is defined as a blood glucose level/dl. It is usually seen in Diabetics due to an improper balance between blood glucose-lowering drugs and food. Patients can have various symptoms, ranging from headaches and palpitations to coma and death. Patients are typically treated with oral carbohydrates and IV carbohydrates/Glucagon if needed. It is essential to understand the presenting complaints of Hypoglycemia as it often complicates the management of Diabetic patients, and sometimes non-Diabetic patients. The symptoms may frequently be mild but can cause significant long-term complications. It is also essential to understand the cause of Hypoglycemia in order to prevent future episodes. In this case series, we describe 50 cases – their presenting complaints, Capillary Blood Glucose (CBG) values, and likely causes for the events. We also describe the management as done in our hospital

Different usage profiles for listeners of music delivered via interactive television, free-to-air radio, and personal music collections

This study examines the audience profile and usage patterns of interactive cable/satellite audio (ICSA) listeners and compares them with listeners of free-to-air radio (FTA) and personal music collections(PMC). A survey of ICSA users in Australia reveals that heavy users of ICSA are also likely to be heavy users of FTA and PMC. However, ICSA listeners are significantly older than FTA or PMC listeners and prefer music formats different to those reflected in radio audiences and CD sales

Hydrogels: Next Generation Atmospheric Water Harvesting Materials

Hydrogels could harvest atmospheric moisture to produce clean drinking water mitigating the global water scarcity woes in future

What’s in a name? : some reflections on naming and identity in prosopography

A prosopography will start from the identification of different individual persons among a mass of name records drawn from the primary sources. Individuals can be discerned even where all or part of the name is missing: for example, “the poor man”, is a person who has been distinguished from others by the description “poor”. But names are normally present in our records, because all human beings have them. They are easy to take for granted, and all too often they are taken for granted even by prosopographers. This paper reflects on the meaning and function of names, and explores their use as descriptions intended to designate and to categorize a single specific individual, even though there may be other persons with the same name. Name evidence is a peculiarly rich resource for the historian, but it cannot be used uncritically but has to be assessed in relation to who recorded the name as we have it – very rarely the name-bearer him/herself –, and how and why.Fundação para a Ciência e a Tecnologi

Australian cardiac rehabilitation exercise parameter characteristics and perceptions of high-intensity interval training: a cross-sectional survey

Purpose: This study explored current demographics, characteristics, costs, evaluation methods, and outcome measures used in Australian cardiac rehabilitation (CR) programs. It also determined the actual usage and perceptions of high-intensity interval training (HIIT). Methods: A cross-sectional observational web-based survey was distributed to 328 Australian CR programs nationally. Results: A total of 261 programs completed the survey (79.6% response rate). Most Australian CR programs were located in a hospital setting (76%), offered exercise sessions once a week (52%) for 6–8 weeks (49%) at moderate intensity (54%) for 46–60 min (62%), and serviced 101–500 clients per annum (38%). HIIT was reported in only 1% of programs, and 27% of respondents believed that it was safe while 42% of respondents were unsure. Lack of staff (25%), monitoring resources (20%), and staff knowledge (18%) were the most commonly reported barriers to the implementation of HIIT. Overall, Australian CR coordinators are unsure of the cost of exercise sessions. Conclusion: There is variability in CR delivery across Australia. Only half of programs reassess outcome measures postintervention, and cost of exercise sessions is unknown. Although HIIT is recommended in international CR guidelines, it is essentially not being used in Australia and clinicians are unsure as to the safety of HIIT. Lack of resources and staff knowledge were perceived as the biggest barriers to HIIT implementation, and there are inconsistent perceptions of prescreening and monitoring requirements. This study highlights the need to educate health professionals about the benefits and safety of HIIT to improve its usage and patient outcomes