scholarly journals Investigation of distortions in the sonar display of elements of complex underwater terrain

Author(s):  
С.А. Лутков ◽  
А.В. Тезиков

Работа посвящена изучению влияния формы отражающей поверхности на результаты картографирования дна и съемки подводных объектов гидроакустическими средствами. Проведена сравнительная оценка качества картирования дна однолучевыми эхолотами и многолучевыми эхолотами. Опыт применения гидроакустических средств измерения глубины показывает, что в районах с выровненным рельефом глубины, измеряемые однолучевыми эхолотами, многолучевыми эхолотами, интерферометрическими эхолотами и механическими лотами, совпадают. В районах со сложным рельефом глубины, измеренные однолучевыми эхолотами, превышают глубины, измеренные многолучевыми эхолотами, и сильно варьируются. Разработана математическая модель для исследования искажений отображения гидролокатора донной поверхности в зависимости от кривизны отражающей поверхности. Получены аналитические зависимости, позволяющие восстановить форму отражающей поверхности по результатам гидроакустических измерений. The work is devoted to the study of the influence of the shape of the reflecting surface on the results of bottom mapping and underwater objects survey using hydro acoustic means. A comparative assessment of the quality of bottom mapping performed by single-beam echo sounders and multi-beam echo sounders was performed. The experience of using hydro acoustic depth measurement tools shows that in areas with leveled terrain, the depths measured by single-beam echo sounders, multi-beam echo sounders, interferometric echo sounders and mechanical lots coincide. In areas with complex terrain, the depths measured by single-beam echo sounders exceed the depths measured by multi-beam echo sounders, and vary greatly. A mathematical model is developed for studying the distortions of the bottom surface sonar display depending on the curvature of the reflecting surface. Analytical dependences are obtained that allow us to restore the shape of the reflecting surface based on the results of sonar measurements.

2020 ◽  
pp. 12-18
Author(s):  
F.A. Urazbahtin ◽  
A.YU. Urazbahtina

A multifactor mathematical model of the welding process of products from aluminum-magnesium alloys, consisting of 71 indicators that assess the quality of the weld, the welding process, costs, equipment operation and quality of the welded material. The model can be used to control and optimize the welding process of products from aluminum-magnesium alloys. Keywords welding, products, aluminum-magnesium alloy, indicators, process parameters, welding equipment, welding materials, electrode sharpening, lining [email protected]


2004 ◽  
Vol 4 (5-6) ◽  
pp. 383-388
Author(s):  
D.M. Rogers

Water is a fundamental necessity of life. Yet water supply and distribution networks the world over are old and lacking in adequate maintenance. Consequently they often leak as much water as they deliver and provide an unacceptable quality of service to the customer. In certain parts of the world, water is available only for a few hours of the day. The solution is to build a mathematical model to simulate the operation of the real network in all of its key elements and apply it to optimise its operation. To be of value, the results of the model must be compared with field data. This process is known as calibration and is an essential element in the construction of an accurate model. This paper outlines the optimum approach to building and calibrating a mathematical model and how it can be applied to automatic calibration systems.


2013 ◽  
Vol 652-654 ◽  
pp. 2450-2454
Author(s):  
Zhi Hong Zhang ◽  
Guo Guang Cheng

The paper describes multi-section round bloom casting using external MEMS, equipped with max section D600mm and min D280mm mold, the center line of D280mm mold not coincident with the axis of stirrer coils. it is exist eccentric electromagnetic stirring of mold which section less than max D600mm, a mathematical model of MEMS has been established, the index of central segregation of D280mm macrostructure had decreased less than 1.12 by optimized parameters of electromagnetic stirring and SEN immerse depth, in the end, the quality of round bloom had improved.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Domenico Cuda ◽  
Sara Ghiselli ◽  
Alessandra Murri

Abstract Background Prevalence of hearing loss increases with age. Its estimated prevalence is 40–50 % in people over 75 years of age. Recent studies agree that declinein hearing threshold contribute to deterioration in sociality, sensitivity, cognition, and quality of life for elderly subjects. The aim of the study presented in this paper is to verify whether or not rehabilitation using first time applied Hearing Aids (HA) in a cohort of old people with hearing impairment improves both speech perception in a noisy environment over time and the overall health-related quality of life. Methods The monocentric, prospective, repeated measurements, single-subject, clinical observational study is to recruit 100 older adults, first-time HA recipients (≥ 65 years).The evaluation protocol is designed to analyze changes in specific measurement tools a year after the first HA usage in comparison with the evaluation before HA fitting. Evaluations will consist of multiparametric details collected through self-report questionnaires completed by the recipients and a series of commonly used audiometric measures and geriatric assessment tools. The primary indicator of changes in speech perception in noise to be used is the Italian version of Oldenburg Satz (OLSA) test whereas the indicator of changes in overall quality of life will be the Assessment of Quality of Life (AQoL) and Hearing Handicap Inventory for the Elderly (HHIE) questionnaires. The Montreal Cognitive Assessment (MoCA) will help in screening the cognitive state of the subjects. Discussion The protocol is designed to make use of measurement tools that have already been applied to the hearing-impaired population in order to compare the effects of HA rehabilitation in the older adults immediately before first HA usage (Pre) and after 1 year of experience (Post). This broad approach will lead to a greater understanding of how useful hearing influences the quality of life in older individuals, and therefore improves potentials for healthy aging. The data is to be analyzed by using an intrasubject endpoint comparison. Outcomes will be described and analyzed in detail. Trial registration This research was retrospectively registered underno. NCT04333043at ClinicalTrials.gov (http://www.clinicaltrials.gov/) on the 26 March 2020. This research has been registered with the Ethics Committee of the Area Vasta Emilia Nord under number 104, date of approval 17/07/2017.


2021 ◽  
pp. 101878
Author(s):  
Md. Solaiman Hossain ◽  
Saad Al-din Sifat ◽  
M. Afzal Hossain ◽  
Sazlina Salleh ◽  
Mofazzal Hossain ◽  
...  

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ratnasari D. Cahyanti ◽  
Widyawati Widyawati ◽  
Mohammad Hakimi

Abstract Background Maternal Death Reviews (MDR) can assist in formulating prevention strategies to reduce maternal mortality. To support MDR, an adequate MDR instrument is required to accurately identify the underlying causes of maternal deaths. We conducted a systematic review and meta-analysis to determine the reliability of maternal death instruments for conducting the MDR process. Method Three databases: PubMed, ProQuest and EBSCO were systematically searched to identify related research articles published between January 2004 and July 2019. The review and meta-analysis involved identification of measurement tools to conduct MDR in all or part of maternal audit. Eligibiliy and quality of studies were evaluated using the Modified Quality Appraisal of Diagnostic Reliability (QAREL) Checklist: Reliability Studies. Results Overall, 242 articles were identified. Six articles examining the instrument used for MDR in 4 countries (4 articles on verbal autopsy (VA) and 2 articles on facility-based MDR) were included. None of studies identified reliability in evaluation instruments assessing maternal audit cycle as a comprehensive approach. The pooled kappa for the MDR instruments was 0.72 (95%CI:0.43–0.99; p < 0.001) with considerable heterogeneity (I2 = 96.19%; p < 0.001). Subgroup analysis of MDR instruments showed pooled kappa in VA of 0.89 (95%CI:0.52–1.25) and facility-based MDR of 0.48 (95%CI:0.15–0.82). Meta-regression analysis tended to show the high heterogeneity was likely associated with sample sizes, regions, and year of publications. Conclusions The MDR instruments appear feasible. Variation of the instruments suggest the need for judicious selection of MDR instruments by considering the study population and assessment during the target periods.


2003 ◽  
Vol 14 (04) ◽  
pp. 181-187 ◽  
Author(s):  
Christopher D. Bauch ◽  
Susan G. Lynn ◽  
Donald E. Williams ◽  
Michael W. Mellon ◽  
Amy L. Weaver

The impact of tinnitus and overall levels of distress were measured with three assessment tools for patients with tinnitus. The Tinnitus Handicap Inventory (THI), the Symptom Checklist-90-Revised (SCL-90-R) and an activities limitations questionnaire were administered to 53 audiology patients reporting tinnitus. Forty-three percent of these patients experienced either quality of life reductions associated with tinnitus, substantial perceived handicap, and/or a high level of distress. Results from the General Severity Index (GSI) of the SCL-90-R indicated that 25% of these patients displayed distress greater than that of the general medical population. The SCL-90-R can be a useful tool for audiologists working with tinnitus patients in assessing needs for referral for psychological or psychiatric counseling.


2019 ◽  
Vol 10 ◽  
Author(s):  
Rebecca L. Krain ◽  
Carolyn J. Kushner ◽  
Meera Tarazi ◽  
Rebecca G. Gaffney ◽  
Andrea C. Yeguez ◽  
...  

2020 ◽  
Vol 1 (4) ◽  
pp. 63-67
Author(s):  
N. N. Shumilina ◽  
◽  
E. E. Larina ◽  

The pride of Russia has always been sable. Sable is unique not only in the quality of its fur, but also in the fact that almost the entire range of its habitat is located on the territory of our country. It was in our country that this animal was first bred in captivity. In this regard, Russia has long had a monopoly on the production of sable skins. In 1969, the black sable breed was approved, and in 1998, the «Saltykov» type of sable was approved. JSC «Saltykovsky Breeding farm» has created a unique herd of dark Sables with evenly spaced gray hair, the skins of which are valued at auctions by 10–30% more expensive [2]. The article presents the results of a comparative assessment of the productive qualities of Sables without gray hair and with different degrees of gray created in JSC «Plemzverosovkhoz » Saltykovsky» livestock. As a result of the analysis, it was found that Sables with gray hair have higher bonitirovki scores (more than 50%). Analyzing the indicators of bonitirovki in males and females with different degrees of gray hair, it was found that the quality of pubescence and color of males with bright gray hair is significantly superior to individuals without gray hair, the same trend is observed in females. In addition, a positive correlation was found (0,79) between the weight of skins in grams, their length and area both in Sables without gray hair, and in individuals with different degrees of gray hair. The most common defect on skins without gray hair is soaking.


Author(s):  
N. I. Kulmakova ◽  
T. A. Magomadov ◽  
N. M. Kostomakhin ◽  
M. N. Dmitrieva ◽  
H. Saleh

The quality of raw materials and goods of animal origin depends first of all on the safety of feed, their balance in terms of the main nutrients and digestibility by the body. As a rule, the lower the quality and safety of feed, the lower the productivity of all types of animals and poultry. The quality of feed is influenced by all stages of their production: growing conditions, harvesting and storage, processing technologies, canning and preparation for feeding. Where high-quality feed is used in diets, maximum productivity and high realization of the genetic potential of animals are obtained. During the storage and processing of plant and animal raw materials its physic and mechanical, biochemical, sanitary and microbiological properties change. This can be avoided only by observing the sanitary and hygienic requirements for bagging, harvesting, and storing feed. The quality of feed is confirmed by its physical, chemical, organoleptic, microbiological and other indicators, which determines the variety of feed control methods at all stages of their turnover. In this connection, the development and strengthening of control over the quality and safety of feed and feed additives is one of the important tasks of modern animal feeding science. The purpose of the work was to carried out a comparative assessment of four samples of the starting compound feed SK-3 for piglets of different producers. The experimental part of the work has been carried out in the laboratory of veterinary expertise at the compound feed plant LLC “Athens-Volga”. For the study of compound feed an average sample was taken from each sample, separating from the combined sample using a hand scoop according to Federal standard 13496.0-2016. Methods of sampling. Quality and safety control was carried out according to organoleptic, physic and chemical, microbiological indicators and the content of mycotoxins in compound feed. Monitoring of compound feed of the compared samples of the starting compound feed for piglets SK-3 according to the studied indicators has shown that all samples meet the sanitary and hygienic requirements of Federal standard of our country.


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