Loran-C performance assurance assessment program

The Federal Aviation Administration (FAA) has accepted the Loran-C navigation system as a supplemental navigation aid for enroute use. Extension of Loran-C utilization to instrument approaches requires establishment of a process by which the current level of performance of the system is always known by the pilot. This system 'integrity' translates into confidence that, if the system is made available to the pilot, the guidance will be correct. Early in the consideration of Loran-C for instrument approaches, the Loran-C Planning Work-Group (LPW) was formed with membership from the FAA, the US Coast Guard, various state governments, aviation users, equipment manufacturers and technical experts. The group was hosted and co-chaired by the National Association of State Aviation Officials (NASAO). This forum was ideal for identification of system integrity issues and for finding the correct process for their resolution. Additionally, the Wild Goose Association (WGA), which is the international Loran-C technical and user forum, regularly brings together members of the FAA, Coast Guard, and the scientific community. Papers and discussions from WGA meetings have been helpful. Given here is a collection of the issues in which Ohio University became involved. Issues definition and resolution are included along with the recommendations in those areas where resolution is not yet complete

Development, validation and reliability of a questionnaire to evaluate coaches' and players' perceptions, learning, and resources regarding the ruck in rugby union

Background: The absence of a valid and reliable research tool for evaluating the attitudes, behaviours, and learning resources of rugby coaches and players concerning the ruck event presents a critical gap in the current rugby research landscape. Objectives: The objective of this study was twofold: firstly, to adapt an existing questionnaire that focussed on the tackle event, and secondly, to validate and establish the reliability of the instrument. The questionnaire is designed to explore the attitudes, behaviours, and learning resources of rugby coaches and players, with a particular emphasis on the ruck event and its potential impact on the field of rugby coach development, coaching practices, and player development. Methods: To assess content, construct, clarity, and relevance validation, a seven-step design process was followed, resulting in a high-quality questionnaire evaluated by a panel of 12 experts. Subsequently, a test-retest procedure involving 15 coaches and 16 players highlights the effectiveness of this questionnaire, emphasising its potential to generate data that can impact the field of rugby coaching and player development. Results: The validity and reliability assessment revealed that the expert panel found the questionnaire to be appropriate, and clear, and the mean time for completion was approximately 22 minutes. The ICC Agreement scores of 0.71 for players and 0.88 for coaches indicate moderate and good agreement respectively, further corroborated by narrow 95% Confidence Intervals. ICC Consistency scores (0.71 for players and 0.87 for coaches) affirmed high response consistency. In Kendall’s W scores, players achieved 0.85, while coaches reached 0.93, with significant F-statistics (p < 0.01) supporting strong agreement. Conclusion: This study introduces a methodically developed questionnaire, recognised for its clarity, reliability, and consistency. It serves as a valuable resource for future research in rugby, possessing the potential to influence coach development, coaching practices, and player development. Therefore, it makes an important contribution to the field

Stock assessment of protogynous fish: evaluating measures of spawning biomass used to estimate biological reference points

In stock assessments, recruitment is typically modeled as a function of females only. For protogynous stocks, however, disproportionate fishing on males increases the possibility of reduced fertilization rates. To incorporate the importance of males in protogynous stocks, assessment models have been used to predict recruitment not just from female spawning biomass (Sf), but also from that of males (Sm) or both sexes (Sb). We conducted a simulation study to evaluate the ability of these three measures to estimate biological reference points used in fishery management. Of the three, Sf provides best estimates if the potential for decreased fertilization is weak, whereas Sm is best only if the potential is very strong. In general, Sb estimates the true reference points most closely, which indicates that if the potential for decreased fertilization is moderate or unknown, Sb should be used in assessments of protogynous stocks. Moreover, for a broad range of scenarios, relative errors from Sf and Sb occur in opposite directions, indicating that estimates from these measures could be used to bound uncertainty

How to Sew on the New Fabrics

Miracle fibers from the test tube- that\u27s what the ads say. And in lots of ways, the new fibers do perform miraculously. The names are familiar- nylon, Dacron, Orlon, Acrilan, Dynel, Arnel. Add to these the resin-treated cottons and rayon. For through this treatment, these old fibers have been given a new behavior pattern

An Optimal Linear Time Algorithm for Quasi-Monotonic Segmentation

Monotonicity is a simple yet significant qualitative characteristic. We consider the problem of segmenting a sequence in up to K segments. We want segments to be as monotonic as possible and to alternate signs. We propose a quality metric for this problem using the l_inf norm, and we present an optimal linear time algorithm based on novel formalism. Moreover, given a precomputation in time O(n log n) consisting of a labeling of all extrema, we compute any optimal segmentation in constant time. We compare experimentally its performance to two piecewise linear segmentation heuristics (top-down and bottom-up). We show that our algorithm is faster and more accurate. Applications include pattern recognition and qualitative modeling.Comment: This is the extended version of our ICDM'05 paper (arXiv:cs/0702142

Tunable Cavity Optomechanics with Ultracold Atoms

We present an atom-chip-based realization of quantum cavity optomechanics with cold atoms localized within a Fabry-Perot cavity. Effective sub-wavelength positioning of the atomic ensemble allows for tuning the linear and quadratic optomechanical coupling parameters, varying the sensitivity to the displacement and strain of a compressible gaseous cantilever. We observe effects of such tuning on cavity optical nonlinearity and optomechanical frequency shifts, providing their first characterization in the quadratic-coupling regime.Comment: 4 pages, 5 figure

An optical fiber hydrogen sensor using a palladium-coated ball lens

A self-referenced optical fiber refractometer using a ball lens as a sensor head has been developed and characterized. A 350-μm ball lens created at the tip of a single mode fiber has been coated with a 40-nm optically thin layer of palladium that reacts with hydrogen to form a hydride, which has a lower reflectivity than pure palladium. Optical reflectance measurements from the tip of the ball lens were performed to determine the hydrogen response. The change in reflectivity is proportional to the hydrogen concentration in the range 0% to 1% hydrogen in air with a detection limit down to 10 ppm (1σ) in air. This technique offers a simple sensor head arrangement, with a larger sampling area (~40 times) than a typical single-mode fiber core. A statistical image analysis of a palladium film, with cracks created by accelerated failure, confirms that the anticipated sensor area for a ball lens sensor head has a more predictable reflectivity than that of a bare fiber core

Outsiders: an exploratory history of IS in corporations

This paper is an exploratory study that provides a brief history of information systems (IS) in corporations that are not part of the Information Technology sector, such as retailers, banks, government agencies and so on. It looks at the development of the IS function and the changing roles of IS practitioners in such organisations over the past 60 years, and assesses how they perceived themselves and were perceived by their peers, by business colleagues and by others. It uses the testimony of successful IS practitioners to provide a grounded perspective on the history of the IS worker over this time. The research identifies a trajectory of a gradual diminishment in the role and status of the IS worker in the corporation over the lifetime of the discipline. It observes that the IS worker has experienced changed fortunes: from a position of influence at the outset, leading to a peak of status and reward in the years up to the millennium; and to the present day where the occupation has a much lower profile. It ascribes this to the increasing commoditisation of IS, manifested by phenomena such as end-user computing, outsourcing and cloud computing. The paper is of relevance to academics who are interested in IS in the corporate organisation; to business professionals, who are sometimes bewildered by their IS colleagues; and to those who work in IS. The research is presented as an interpretative study and is intended to help future researchers frame questions and design research projects. It also aims to inform and witness, and provide a perspective on a currently neglected part of the business world

Return to driving after traumatic brain injury : a British perspective

Primary Objective: to identify current legal situation, and professional practice in assisting persons with traumatic brain injury (TBI) to return to safe driving after injury. Methods and Procedures A brief review of relevant literature, a description of the current statutory and quasi-statutory authorities regulating return to driving after TBI in the UK, and a description of the nature and resolution of clinical and practical dilemmas facing professionals helping return to safe driving after TBI. Each of the 15 UK mobility centres was contacted and literature requested; in addition a representative of each centre responded to a structured telephone survey. Main Outcome and Results: The current situation in Great Britain is described, with a brief analysis of the strengths and weaknesses both of the current statutory situation, and also the practical situation (driving centres), with suggestions for improvements in practice. Conclusion Although brain injury may cause serious limitations in driving ability, previous drivers are not routinely assessed or advised regarding return to driving after TBI