Benchmarking Image Processing Algorithms for Unmanned Aerial System-Assisted Crack Detection in Concrete Structures

This paper summarizes the results of traditional image processing algorithms for detection of defects in concrete using images taken by Unmanned Aerial Systems (UASs). Such algorithms are useful for improving the accuracy of crack detection during autonomous inspection of bridges and other structures, and they have yet to be compared and evaluated on a dataset of concrete images taken by UAS. The authors created a generic image processing algorithm for crack detection, which included the major steps of filter design, edge detection, image enhancement, and segmentation, designed to uniformly compare dierent edge detectors. Edge detection was carried out by six filters in the spatial (Roberts, Prewitt, Sobel, and Laplacian of Gaussian) and frequency (Butterworth and Gaussian) domains. These algorithms were applied to fifty images each of defected and sound concrete. Performances of the six filters were compared in terms of accuracy, precision, minimum detectable crack width, computational time, and noise-to-signal ratio. In general, frequency domain techniques were slower than spatial domain methods because of the computational intensity of the Fourier and inverse Fourier transformations used to move between spatial and frequency domains. Frequency domain methods also produced noisier images than spatial domain methods. Crack detection in the spatial domain using the Laplacian of Gaussian filter proved to be the fastest, most accurate, and most precise method, and it resulted in the finest detectable crack width. The Laplacian of Gaussian filter in spatial domain is recommended for future applications of real-time crack detection using UAS

'I just want a job' : what do we really know about young people in jobs without training?

Over recent years, a central concern of policy has been to drive up post-16 participation rates in full-time education and address the needs of young people not in education, employment or training (NEET). As a result, young people who enter work which is classified as 'without training' at 16/17 have largely been ignored. However, the decision to Raise the Participation Age (RPA) for continuing in learning for all 17-year olds from 2013 and for all 18-year olds from 2015 in England, together with a growing unease about the impact of the current recession on youth unemployment rates, have revived interest in the 'jobs without training' (JWT) group. This paper draws on the findings from two studies: first, a qualitative study in two contrasting local labour markets, of young people in JWT, together with their employers and parents; and second, an evaluation of the Learning Agreement Pilots (LAP), which was the first policy initiative in England targeted at the JWT group. Both studies reveal a dearth of understanding about early labour market entrants and a lack of policy intervention and infrastructure to support the needs of the JWT group throughout the UK. From this, it is concluded that questionable assumptions have been made about the composition and the aspirations of young people in JWT, and their employers, on the basis of little or no evidence. As a consequence, a policy 'quick fix' to satisfy the RPA agenda will not easily be achieved. If the decision to raise the participation age is adopted also by the Welsh and Scottish parliaments, similar challenges may have to be faced

The question of ‘alternatives’ within food and drink markets and marketing: introduction to the special issue

The question of 'alternatives' within food and drink markets and marketing: introduction to the special issu

Evidence for biased agonists and antagonists at the endothelin receptors.

Biased ligands represent a new strategy for the development of more effective and better tolerated drugs. To date there has been a paucity of research exploring the potential of ligands that exhibit either G protein or β-arrestin pathway selectivity at the endothelin receptors. Re-analysis of data may allow researchers to determine whether there is existing evidence that the endogenous ET peptides or currently available agonists and antagonists exhibit pathway bias in a particular physiological or disease setting and this is explored in the review. An alternative to molecules that bind at the orthosteric site of the ET receptors are cell penetrating peptides that interact with a segment of an intracellular loop of the receptor to modify signalling behaviour. One such peptide IC2B has been shown to have efficacy in a model of pulmonary arterial hypertension. Finally, understanding the molecular pathways that contribute to disease is critical to determining whether biased ligands will provide clinical benefit. The role of ETA signalling in ovarian cancer has been delineated in some detail and this has led to the suggestion that the development of ETA G protein biased agonists or β-arrestin biased antagonists should be explored.This study was supported by the Wellcome Trust (grant number WT107715). We thank Papworth Hospital NHS Trust Tissue Bank for assistance.This is the final version of the article. It first appeared from Elsevier via https://doi.org/10.1016/j.lfs.2016.02.06

Generation of wavelength tunable optical pulses with SMSR exceeding 50 dB by self-seeding a gain-switched source containing two FP lasers

In this letter, we show the generation of shorter pulses (∼20 ps) that exhibit side mode suppression ratios (SMSR's) greater than 50 dB and wider tuning range (48.91 nm). Our technique is based on the self-seeding of a gain-switched source containing two FP lasers

Optical pulse generation and signal processing for the development of high-speed OTDM networks

Due to the continued growth of the Internet and the introduction of new broadband services, it is anticipated that individual channel data rates may exceed lOOGbit/s in the next 5-10 years. In order to operate at such high line rates new techniques for optical pulse generation and optical signal processing will have to be developed. As the overall data rate of an OTDM network is essentially determined by the temporal separation between data channels, an optical pulse source that is capable of producing ultra-short optical pulses at a high repetition rate and with wavelength tunability will be important, not only for OTDM, but for vanous applications in WDM and hybrid WDM/OTDM networks. This work demonstrates that by using the gain-switching technique, commercially available laser diodes can be used in the development of nearly transform-limited optical pulses that are wavelength tunable over nearly 65nm with durations ranging from 12-30ps and a Side-Mode Suppression Ratio (SMSR) exceeding 60dB. New optical signal processing techniques will also have to be developed in order to operate at individual data rates in excess of lOOGbit/s. Only nonlinear optical effects, present in fibres, semiconductors and optical crystals, can be employed as these occur on time scales in the order of a few-femtoseconds (10“15 5), with an example being Two-Photon Absorption (TPA) in semiconductors. This thesis describes a specially designed microcavity that can enhance the Two-Photon Absorption (TPA) response by over three orders of magnitude at specific wavelengths. A theoretical model demonstrating error-free demultiplexing of a 250Gbit/s OTDM signal via a TPA microcavity has been developed. Experimental work is also presented demonstrating the use of a TPA microcavity for optical sampling of 100GHz signals with a temporal resolution of 1 ps9 and system sensitivity of 0 009 (mW)2 This value for the sensitivity is the lowest ever reported for a TPA-based sampling system

Value Assessment and Implementation Tradeoffs for Production-Heavy Truck Active Noise Control

Despite a long history, the implementation tradeoffs and value assessment criteria of active noise control (ANC) are not well established. With commercial heavy truck adaptive ANC controllers now available, there is a need for an understanding of the unique performance-to-cost ratio characteristics of these systems. Also, due to the specific spectral region that these systems are applicable to, studies of the physiological effects of broadband noise poorly represent the positive impact of ANC. This paper presents a collection of implementation tradeoff metrics unique to active noise control systems. In addition, evaluation issues and research are identified that will help to validate ANC benefits that are accepted, but insufficiently supported

Road Map to Becoming a Physician Assistant

The field of medicine is under constant change and reconstruction, especially when it comes to healthcare practitioners. When a demand is placed on the system, healthcare providers must figure out how they can satisfy the medical needs of the population. Within the past few decades there has been a shortage of people who are capable of fulfilling these needs. For this reason a new profession has been developed; it is called a Physician Assistant (PA). Professionals with this title have been through a rigorous training modeled after what a medical student goes through, but it is condensed into a much shorter program. Once completed, a PA must pass a national board exam, and then they can work in practically any healthcare setting to diagnose and treat patients, including writing prescriptions, ordering tests, and interpreting labs results. The one limitation is the PA must work under the supervision of a doctor (MD or DO). However, supervision varies and can simply mean that the doctor needs to be available by phone. Undergraduate students at theUniversityofRhode Islandwho are planning on going into healthcare may consider becoming a Physician Assistant. The problem with that is since the programs are newer than other healthcare options; there are currently a very limited amount of resources available to students exploring this opportunity. The requirements are different than those of medical schools, and can vary from PA school to PA school. The field also demands the student to experience a substantial amount of direct patient care to even be considered a good candidate. If an applicant is unaware of these requirements, he or she may need to take a few years off after graduating before being a strong enough applicant to be accepted into a program to become a PA. As a senior, I have already been through this application process. It is highly competitive because there is less schooling and less expense (than medical school) and the profession itself is ultimately appealing. I found that the students at URI could benefit from a resource that guides them through the steps of becoming a successful applicant. Therefore I have compiled a web-based resource that can be used as an advising tool in the future. I researched background information on the profession, which includes comparing it to other similar professions and job satisfaction. I also looked into specific resources that theUniversityofRhode Islandhas to offer students who are headed down the path to becoming a Physician Assistant. This includes recommended courses, campus involvement, and ways to get hands-on patient care. Finally, I take the students through the application process. Graduate programs require personal statements, letters of reference and if you seem promising, an interview. I believe that many URI students seeking to become a Physician Assistant will benefit from my research in the future