scholarly journals Recent Advancements and Perspectives in UAS-Based Image Velocimetry

Drones ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 81
Author(s):  
Silvano Fortunato Dal Dal Sasso ◽  
Alonso Pizarro ◽  
Salvatore Manfreda

Videos acquired from Unmanned Aerial Systems (UAS) allow for monitoring river systems at high spatial and temporal resolutions providing unprecedented datasets for hydrological and hydraulic applications. The cost-effectiveness of these measurement methods stimulated the diffusion of image-based frameworks and approaches at scientific and operational levels. Moreover, their application in different environmental contexts gives us the opportunity to explore their reliability, potentialities and limitations, and future perspectives and developments. This paper analyses the recent progress on this topic, with a special focus on the main challenges to foster future research studies.

2018 ◽  
Vol 7 (11) ◽  
pp. 445 ◽  
Author(s):  
Niti Mishra ◽  
Kumar Mainali ◽  
Bharat Shrestha ◽  
Jackson Radenz ◽  
Debendra Karki

Understanding ecological patterns and response to climate change requires unbiased data on species distribution. This can be challenging, especially in biodiverse but extreme environments like the Himalaya. This study presents the results of the first ever application of Unmanned Aerial Systems (UAS) imagery for species-level mapping of vegetation in the Himalaya following a hierarchical Geographic Object Based Image Analysis (GEOBIA) method. The first level of classification separated green vegetated objects from the rest with overall accuracy of 95%. At the second level, seven cover types were identified (including four woody vegetation species). For this, the suitability of various spectral, shape and textural features were tested for classifying them using an ensemble decision tree algorithm. Spectral features alone yielded ~70% accuracy (kappa 0.66) whereas adding textural and shape features marginally improved the accuracy (73%) but at the cost of a substantial increase in processing time. Contrast in plant morphological traits was the key to distinguishing nearby stands as different species. Hence, broad-leaved versus fine needle leaved vegetation were mapped more accurately than structurally similar classes such as Rhododendron anthopogon versus non-photosynthetic vegetation. Results highlight the potential and limitations of the suggested UAS-GEOBIA approach for detailed mapping of plant communities and suggests future research directions.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
K Mullavelil ◽  
V George ◽  
A Thannikkal ◽  
R Aravindakshan ◽  
D John ◽  
...  

Abstract Background Only little attention has been paid to treatment strategies of chronic disease conditions that require long term treatment and repeated hospitalizations Purpose Our aim was to review cost-effectiveness of guideline directed medical therapy of heart failure in India and identify drugs that can be made available free of cost or at subsidized rates to the patient population. Methods Data extracted from ten landmark trials in heart failure was used to compute Number Needed to Treat (NNT) and Cost Needed to Treat (CNT) of drugs used in heart failure, to prevent cardiovascular mortality and heart failure re-hospitalization using HDS Plotter- Incremental Cost Effectiveness Calculator. Since various brands (i.e. trade names) with wide cost range are available in Indian market, the average retail price in Indian Rupees for year 2019 was considered and converted to US dollars and used for the analysis.NNT and CNT of each drug was computed and the cost-effectiveness was analyzed. WHO recommendation of three times per capita GDP was used as the cost effectiveness threshold. Results Medications that were labeled as class I for the treatment of heart failure, were included in our analysis. Ivabradine, Valsartan and Angiotensin Receptor Neprilysin inhibitor (ARNi) did not meet the cost effectiveness criteria for preventing cardio-vascular mortality. For prevention of heart failure re-hospitalization, all drugs except ARNi, met the cost effectiveness threshold. Conclusion Any future research would need to consider compliance factor along with Willingness to Pay (WTP) to understand the real acceptance of these drugs on the ground in India. Log prices (in US$) of various HF drugs Funding Acknowledgement Type of funding source: None


Author(s):  
Richard R. Suminski ◽  
Gregory M. Dominick ◽  
Matthew Saponaro

Evidence suggests that video captured with a wearable video device (WVD) may augment or supplant traditional methods for assessing park use. Unmanned aerial systems (UASs) are used to assess human activity, but research employing them for park assessments is sparse. Therefore, this study compared park user counts between a WVD and UAS. A diverse set of 33 amenities (e.g., playground) in three parks were videoed simultaneously by one researcher wearing a WVD and another operating the UAS. Assessments were done at 12 p.m. and 7 p.m. on weekends, with one park evaluated on two occasions 7 days apart. Two investigators independently reviewed videos and reached consensus on the counts of individuals at each amenity. Intraclass correlation coefficients (ICCs) were used to determine intra- and interrater reliabilities. A total of 404 (M = 4.7; SD = 9.6) and 389 (M = 4.5; SD = 9.0) individuals were counted in the UAS and WVD videos, respectively. Absolute agreement was 86% (74/86) and 100% when no individuals were using the amenity. Whether using all 86 videos or only videos having people (48 videos), ICCs indicated excellent reliability (ICC = .99; p < .001). The totals seen for the repeated measures were UAS = 146 and WVD = 136 for Day 1 and UAS = 169 and WVD = 161 for Day 2. Intrarater reliability was excellent for the UAS (ICC = .92; p < .001) and good for the WVD (ICC = .89; p < .001). Disagreement was mainly due to obstructions—people behind or under structures. This study provides support for the use of UASs for counting park users and future research examining the potential benefits of video analysis for assessing park use.


Atmosphere ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 416 ◽  
Author(s):  
Astrid Lampert ◽  
Barbara Altstädter ◽  
Konrad Bärfuss ◽  
Lutz Bretschneider ◽  
Jesper Sandgaard ◽  
...  

Unmanned aerial systems (UAS) fill a gap in high-resolution observations of meteorological parameters on small scales in the atmospheric boundary layer (ABL). Especially in the remote polar areas, there is a strong need for such detailed observations with different research foci. In this study, three systems are presented which have been adapted to the particular needs for operating in harsh polar environments: The fixed-wing aircraft M 2 AV with a mass of 6 kg, the quadrocopter ALICE with a mass of 19 kg, and the fixed-wing aircraft ALADINA with a mass of almost 25 kg. For all three systems, their particular modifications for polar operations are documented, in particular the insulation and heating requirements for low temperatures. Each system has completed meteorological observations under challenging conditions, including take-off and landing on the ice surface, low temperatures (down to −28 ∘ C), icing, and, for the quadrocopter, under the impact of the rotor downwash. The influence on the measured parameters is addressed here in the form of numerical simulations and spectral data analysis. Furthermore, results from several case studies are discussed: With the M 2 AV, low-level flights above leads in Antarctic sea ice were performed to study the impact of areas of open water within ice surfaces on the ABL, and a comparison with simulations was performed. ALICE was used to study the small-scale structure and short-term variability of the ABL during a cruise of RV Polarstern to the 79 ∘ N glacier in Greenland. With ALADINA, aerosol measurements of different size classes were performed in Ny-Ålesund, Svalbard, in highly complex terrain. In particular, very small, freshly formed particles are difficult to monitor and require the active control of temperature inside the instruments. The main aim of the article is to demonstrate the potential of UAS for ABL studies in polar environments, and to provide practical advice for future research activities with similar systems.


Author(s):  
Jiajun Wei ◽  
Matthew L. Bolton ◽  
Laura Humphrey

Psychometrics are increasingly being used to evaluate trust in the automation of safety-critical systems. There is no consensus on what the highest level of measurement is for psychometric trust. This is important as the level of measurement determines what mathematics and statistics can be meaningfully applied to ratings. In this work, we introduce a new method for determining what the maximum level of measurement is for psychometric ratings. We use this to assess the level of measurement of trust in automation using human ratings about the behavior of unmanned aerial systems performing search tasks. Results show that trust is best represented at an ordinal level and that it can be treated as interval in most situations. It is unlikely that trust in automation ratings are ratio. We discuss these results, their implications, and future research.


1996 ◽  
Vol 13 (2) ◽  
pp. 124-135 ◽  
Author(s):  
Mervyn Jackson ◽  
Ray Wilks

There has been extensive debate over the last three decades about which professional groups should receive government-funded rebates in the mental health field. Cognitive-behaviour therapists appear to be in the best position to demonstrate clinical efficacy, but have failed to demonstrate cost-effectiveness of cognitive-behaviour therapy. There is a need to demonstrate the cost of behaviour therapy as the first step in determining the cost-effectiveness of behaviour therapy compared to the traditional (medical-based) interventions. Using archival data from a university-based psychology clinic specialising in cognitive-behavioural interventions with child and adolescent problems, the present research determined the cost of successful treatment programs with the clinic's major referral areas: nocturnal enuresis, behaviour management, and education-based problems. Analysing 77 cases, it was found that there were significant between group differences in the number and total duration of face-to-face interviews, in the number of other contacts between therapist and client, in total therapist time, and in the estimated average cost of cases. There emerged different treatment patterns for each clinical problem, and these were reflected in costing. A number of research and methodological issues are explored. Implications for future research on cost-effectiveness and the subsequent collection of comparative data across clinics and a variety of clinical problem areas are discussed.


2012 ◽  
Vol 28 (3) ◽  
pp. 241-248 ◽  
Author(s):  
Lanting Lu ◽  
Jaime Peters ◽  
Chris Roome ◽  
Ken Stein

Objectives:The aim of this study was to evaluate the cost-effectiveness of alemtuzumab (CAMPATH-1H) compared with conventional chemotherapy in people with T-cell prolymphocytic leukemia (T-PLL).Methods:We developed a decision-analytic model to assess the costs and benefits of alemtuzumab or conventional therapy based on their effects on quality of life of patients. The main outcome was the incremental cost-effectiveness ratio incorporating costs per additional quality-adjusted life-year (QALY) gained over lifetime. Due to the limited data available, a large number of assumptions had to be made to construct the cost-utility model. One-way, multi-way, and probabilistic sensitivity analyses (PSA) were conducted to explore the impact of these uncertainties. Expected values of perfect information were also calculated for four specific scenarios.Results:Depending on different key assumptions made, the PSA suggested distinct conclusions using a willingness-to-pay threshold of 30,000 GBP per QALY gained. Using this threshold, the probability that alemtuzumab would be cost-effective varies from 0 percent to 53 percent for the four modeled scenarios. Population expected value of perfect information analysis suggests that resolving the parameter uncertainty in the analysis for people with T-PLL in the United Kingdom would have considerable value—up to 5.3 million euro.Conclusions:Alemtuzumab appears more likely to be cost-effective if used earlier in the course of T-PLL and where it replaces the use of multiple alternative therapies. However, cost-effectiveness is highly uncertain and future research is clearly justified. Nevertheless, our analysis demonstrates the feasibility of considering the cost-effectiveness of an agent despite the presence of significant uncertainty to provide appropriate assessment information to policy makers.


Author(s):  
E. Salami ◽  
J. A. Soler ◽  
R. Cuadrado ◽  
C. Barrado ◽  
E. Pastor

Unmanned aerial systems (UAS, also known as UAV, RPAS or drones) have a great potential to support a wide variety of aerial remote sensing applications. Most UAS work by acquiring data using on-board sensors for later post-processing. Some require the data gathered to be downlinked to the ground in real-time. However, depending on the volume of data and the cost of the communications, this later option is not sustainable in the long term. This paper develops the concept of virtualizing super-computation on-board UAS, as a method to ease the operation by facilitating the downlink of high-level information products instead of raw data. Exploiting recent developments in miniaturized multi-core devices is the way to speed-up on-board computation. This hardware shall satisfy size, power and weight constraints. Several technologies are appearing with promising results for high performance computing on unmanned platforms, such as the 36 cores of the TILE-Gx36 by Tilera (now EZchip) or the 64 cores of the Epiphany-IV by Adapteva. The strategy for virtualizing super-computation on-board includes the benchmarking for hardware selection, the software architecture and the communications aware design. A parallelization strategy is given for the 36-core TILE-Gx36 for a UAS in a fire mission or in similar target-detection applications. The results are obtained for payload image processing algorithms and determine in real-time the data snapshot to gather and transfer to ground according to the needs of the mission, the processing time, and consumed watts.


2019 ◽  
Vol 15 (6) ◽  
pp. 155014771985071 ◽  
Author(s):  
Truong Duy Dinh ◽  
Rustam Pirmagomedov ◽  
Van Dai Pham ◽  
Aram A Ahmed ◽  
Ruslan Kirichek ◽  
...  

The success of the wilderness search and rescue missions is highly dependent on the time required to search for the lost person. The use of unmanned aerial systems may enhance search and rescue missions by supplying aerial support of the search process. There are unmanned aerial system–based solutions, which are capable of detecting the lost person using computer vision, infrared sensors, and detection of a mobile phone signal. The most pressing issue is reducing the cost of a search and rescue mission. Thus, to improve the efficiency of the resource utilization in wilderness search scenario, we consider the use of unmanned aerial system for both mobile phone detection and enabling Wi-Fi communication for the ground portion of the search and rescue team. Such an approach does not require specific additional tools (e.g. access point, specific user equipment) for communication, which reduces the cost and improves the scalability and coordination of the search and rescue mission. As a result, the article provides methods of searching the wilderness for a person using beacon signals from a mobile phone for two situations: when the distance to the source of emergency signals is unknown and when the distance is known. In addition, the voice transmission delay and the number of unmanned aircrafts are found to guaranty the quality of a call.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Stefania Manetti ◽  
Giuseppe Turchetti ◽  
Francesco Fusco

Abstract Background Falls may lead to hip fractures, which have a detrimental effect on the prognosis of patients as well as a considerable impact on healthcare expenditures. Since a secondary hip fracture (SHF) may lead to even higher costs than primary fractures, the development of innovative services is crucial to limit falls and curb costs in high-risk patients. An early economic evaluation assessed which patients with a second hip fracture could benefit most from an exoskeleton preventing falls and whether its development is feasible. Methods The life-course of hip fractured patients presenting with dementia or cardiovascular diseases was simulated using a Markov model relying on the United Kingdom administrative data and complemented by published literature. A group of experts provided the exoskeleton parameters. Secondary analyses included a threshold analysis to identify the exoskeleton requirements (e.g. minimum impact of the exoskeleton on patients’ quality of life) leading to a reimbursable incremental cost-effectiveness ratio. Similarly, the uncertainty around these requirements was modelled by varying their standard errors and represented alongside population Expected Value of Perfect Information (EVPI). Results Our base-case found the exoskeleton cost-effective when providing a statistically significant reduction in SHF risk. The secondary analyses identified 286 cost-effective combinations of the exoskeleton requirements. The uncertainty around these requirements was explored producing further 22,880 scenarios, which showed that this significant reduction in SHF risk was not necessary to support the exoskeleton adoption in clinical practice. Conversely, a significant improvement in women quality of life was crucial to obtain an acceptable population EVPI regardless of the cost of the exoskeleton. Conclusions Our study identified the exoskeleton requisites to be cost-effective and the value of future research. Decision-makers could use our analyses to assess not only whether the exoskeleton could be cost-effective but also how much further research and development of the exoskeleton is worth to be pursued.


Sign in / Sign up

Export Citation Format

Share Document