cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Energy Levels in Transition Diets
Creators: name: Varga, Gabriella A.
Publisher: name: American Association of Bovine Practitioners  Proceedings of the Annual Conference
Year: 2002

description: Dry matter intake may decrease 10 to 30% during the period three weeks prior to calving. During the last 3 weeks prior to calving it is recommended that the energy density be in the range of 1.5 to 1.6 Meal NE/kg dry matter (DM), crude protein (CP) in the range of 13-14%, nonfiber carbohydrate between 33 and 38% and neutral detergent fiber (NDF) 32-50%. More information is needed regarding the metabolizable protein and energy needs of the fetus, placenta, fetal fluids, uterus and mammary gland during the dry period. Proper formulation of rations for protein, energy density, fiber and nonforage fiber carbohydrates will help to increase intake prior to calving. Management of body condition and cow comfort are also critical to assure an excellent transition program.
description: American Association of Bovine Practitioners Proceedings of the Annual Conference, 2002
title: 02_0782
Creators: name: Wesley Baldwin, John
name: Baldwin, John W.
Publisher: name: NAKALA - https://nakala.fr (Huma-Num - CNRS)
publisherIdentifier: https://ror.org/04ces3204
publisherIdentifierScheme: ROR
Year: 2018
Subjects: subject: LaMOP
subject: Laboratoire de Médiévistique Occidentale de Paris

description: L'ensemble de ces notes ont été crée par John Baldwin lors d'une de ses premières périodes de résidence à Paris. Ces documents comprennent tous les magistri qu’il avait pu rencontrer dans ses sources. Aux XIIème et XIIIème siècles, les universités n'existant pas encore, le titre de magister s'il évoque certainement une compétence n'est pas rattaché de façon systématique au passage par les écoles. De surcroît, les magistris sont le plus souvent désignés par leur seul prénom. La lecture de ces données est donc difficile et suppose un long travail pour tenter d'identifier un individu auquel on pourrait rattacher plusieurs mentions. John Baldwin avait donc renoncé à utiliser ces données pour donner un prolongement à sa magnifique étude sur les gradués d'université et leur emploi par les Capétiens et les Plantagenêts. Néanmoins, il a conservé ces données et elles sont potentiellement très utile dans le cadre de Studium, comme le sont toutes les mentions dans les volumes des Fasti Ecclesiae Gallicanae de chanoines portant ce titre de magister sans autres précisions. L'ampleur des dépouillements rend ces données très utiles et nous devons une grande reconnaissance à John Baldwin pour avoir pris la peine de faire photocopier ses fiches et de nous les avoir transmises amicalement.
Les données ainsi que les images des fiches sont accessibles sur le site Internet à l'adresse suivante : http://studium-baldwin.lamop.fr/.
Les transcriptions des fiches ont été effectuées par des étudiants de Paris 1 Panthéon - Sorbonne mais elles n'ont pas été corrigées par la suite.
description: Relation: https://lamop.hypotheses.org/
Thinking Outside the Box
Creators: name: Stevenson, Deborah
Publisher: name: American Association of Bovine Practitioners  Proceedings of the Annual Conference
Year: 2002

description: Do the veterinarians in your clinic work too many hours and still not have time to get everything accomplished? There are many traditional options to remedy this situation, such as working more hours or not taking any new clients. However, there is another option ... hiring a Registered (Certified) Veterinary Technician. You're probably asking yourself "How will this help me?" We will answer that question during this presentation and have you beginning to "think outside the box"! Each practice situation will bring unique opportunities based upon the type of practice and applicable laws for its location. These tasks, delegated by the veterinarian to the technician, may include both traditional "nursing" skills as well as tasks in your herd health programs. This team approach, though new in food animal practice, has been long used in the human nursing and dental professions. The bottom line is that utilizing technicians as part of the veterinary team will positively impact the clinic business ... the doctors are more efficient, the technicians are challenged to do what they are trained to do and the client gets outstanding service.
description: American Association of Bovine Practitioners Proceedings of the Annual Conference, 2002
Preface: Technical commission II
Creators: name: Yilmaz, Alper
name: Wegner, Jan Dirk
name: Qin, Rongjun
name: Remondino, Fabio
name: Fuse, Takashi
name: Toschi, Isabella
Publisher: name: ETH Zurich
Year: 2022

description: ISPRS Technical Commission II focuses on geometric, radiometric and multitemporal aspects of image- and range-based 3D surveying and modeling. Specifically, Commission II focuses on research and developments on image orientation, point cloud generation and processing, 3D feature extraction, dynamic and static scene analysis, sensor fusion, data integration, and machine learning for geospatial data analysis. TC II considers the applications of these focus areas in the fields of mapping, infrastructure monitoring, heritage studies, space exploration, underwater photogrammetry and environmental engineering.
description: International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, XLIII-B2-2022
description: ISSN:1682-1750
description: ISSN:2194-9034
description: ISSN:1682-1777
Fertility Factors
Creators: name: Senger, P. L.
Publisher: name: American Association of Bovine Practitioners  Proceedings of the Annual Conference
Year: 2002

description: The goal of every dairy management team should be to maximize the efficiency of high producing dairy cows so that profitability will increase. The standards which define a high producing dairy cow will move upward as long as genetic progress continues to be made, management priority is placed on cow comfort and improving milk yield, nutrition is improved and new technology is developed and implemented. The goal of this paper is to present a reasonable case that successful reproductive management in high producing cows can be realized best by focusing on the right factors; the ones that impact fertility the most. This paper will not provide specific programs or recommendations for improvements. These are available from numerous other sources and specific programs must be custom-designed for each herd.
description: American Association of Bovine Practitioners Proceedings of the Annual Conference, 2002
What Goes In Must Come Out
Creators: name: Satter, Larry
Publisher: name: American Association of Bovine Practitioners  Proceedings of the Annual Conference
Year: 2002

description: Phosphorus (P) stimulates growth of algae in freshwater lakes and streams. The loss of P to surface runoff from fields that contain excess P are typically greater than from fields managed to supply adequate but not excessive P for crop growth. As dairy operations have increased in size, manure application rates of P have often exceeded plant uptake of P, resulting in elevated soil test P. High levels of P in lactating cow diets exacerbates the problem, since P fed in excess of the cow's requirement is excreted in the feces in a largely soluble form. Removing excess P from dairy diets not only reduces P content of manure, but sharply reduces the amount of soluble P excreted, thus reducing risk of surface runoff. Most lactating dairy cow diets can have their P content reduced by 20%. This results in a 25-30% reduction in P content of manure, and a similar reduction in the amount of land required to accommodate the manure.
description: American Association of Bovine Practitioners Proceedings of the Annual Conference, 2002
Lighting the Way to Optimal Cow Performance
Creators: name: Dahl, Geoffrey E.
Publisher: name: American Association of Bovine Practitioners  Proceedings of the Annual Conference
Year: 2002

description: Management of lighting in dairy housing has recently received interest as a method to improve production. In addition, recent evidence suggests that photoperiod manipulation can be used to enhance disease resistance, especially during the dry period. As with any management approach, there are certain guidelines that require consideration for successful implementation. This review covers the biology of photoperiod responses in cattle, impacts on production and health, and suggestions for implementation.
description: American Association of Bovine Practitioners Proceedings of the Annual Conference, 2002
The Influence of Barn Design on Dairy Cow Hygiene, Lameness and Udder Health
Creators: name: Cook, Nigel B.
Publisher: name: American Association of Bovine Practitioners  Proceedings of the Annual Conference
Year: 2002

description: A system of hygiene scoring is described which charts the distribution of manure over three areas of the body; udder, lower legs, and upper leg and flank. The practical relevance of quantifying hygiene is described in relation to the prevalence of mastitis and lameness. Aspects of freestall and tiestall design which impact hygiene and lying times are reviewed and the link between cow comfort and lameness is explored.
description: American Association of Bovine Practitioners Proceedings of the Annual Conference, 2002
Bedding Management and Udder Health
Creators: name: Reneau, Jeffrey K.
name: Bey, Russell F.
name: Farnsworth, Ralph J.
Publisher: name: American Association of Bovine Practitioners  Proceedings of the Annual Conference
Year: 2002

description: The role of bedding management in controlling mastitis infection in lactating cows is often underestimated. Bedding management for heifers and dairy cattle that are in their dry period is frequently overlooked and often poorly managed. This is a costly mistake on many dairies.
description: American Association of Bovine Practitioners Proceedings of the Annual Conference, 2002
Feedlot Biosecurity-Security in the Real World
Creators: name: Griffin, Dee
Publisher: name: American Association of Bovine Practitioners  Proceedings of the Annual Conference
Year: 2002

description: Biosecurity and security are different production issues, but both are important and must be properly addressed to protect the health oflivestock in an operation. The introduction of disease causing organisms (pathogens) into a livestock operation can either be intentional, as would be the situation with bioterrorism, or unintentional, as is often the case with improper biosecurity application procedures. The biosecurity and security activities will have unique standard operating procedures (SOP) and good management practices (GMP). The security and biosecurity SOP and GMP standards can vary between operations depending on the type and class of cattle raised or produced by the operation, and the operation's biosecurity goals and objectives. The security and biosecurity SOP and GMP outlined in this paper are generic and may not match the needs of different cattle operations. It will be important to evaluate the specific biosecurity and security needs of each production location and make adjustments in the generic checklists included in this paper. The biosecurity and security needs of each production location should be reevaluated on a regularly scheduled basis.
description: American Association of Bovine Practitioners Proceedings of the Annual Conference, 2002
Microbiological Water Quality for Optimal Livestock Production and Health
Creators: name: LeJeune, Jeffrey
name: Gay, John M.
Publisher: name: American Association of Bovine Practitioners  Proceedings of the Annual Conference
Year: 2002

description: Relative to standards for humans, water in the cattle environment is often of poor or unknown microbiological quality, whether it is surface drinking water, recycled flush water, wash water, cooling water or drinking water in troughs. The microbial ecology is complex and not well understood. Microbial contamination originates from the environment, the feces of cattle or other animals, and, due to oral residues, even the normal act of drinking. In many circumstances, the quality is regarded as uncontrollable at best. Although pathogenic bacteria and zoonotic foodborne pathogens are found in cattle water with some frequency, the health, production and food safety risks associated with cattle drinking or contacting water contaminated with these microorganisms remains largely undefined. As production and health consequences from the presence of these agents are certainly biologically plausible and some evidence suggests that they do exist, additional research is needed to quantify these risks. If these risks prove to be unacceptable under current management conditions and consumer expectations, methods to ensure microbiologically cleaner water for livestock will need to be identified.
description: American Association of Bovine Practitioners Proceedings of the Annual Conference, 2002
Feedlot Diagnostics and Common Sense
Creators: name: Glock, Robert D.
Publisher: name: American Association of Bovine Practitioners  Proceedings of the Annual Conference
Year: 2002

description: Approaches to feedlot diagnostics continually change as new information becomes available to managers, veterinarians and diagnosticians. Record keeping has evolved to a point where considerable precise information regarding performance, demographics and health issues can be quickly generated. Diagnostic laboratories continue to develop more precise techniques for detecting pathogens, deficiencies and tissue damage. The role of the attending veterinarian becomes more challenging and demanding because production costs and performance issues dictate the need for better health performance. Only the on-site veterinarian can provide the skill needed to decide what information is needed and to assimilate that information into useful decision-making. Sensitive and specific diagnostic tests must be viewed with perspective to avoid being misled into over-interpreting diagnostic information.
description: American Association of Bovine Practitioners Proceedings of the Annual Conference, 2002
Factors Affecting Profitability of the Cow-Calf Enterprise
Creators: name: Dunn, Barry H.
Publisher: name: American Association of Bovine Practitioners  Proceedings of the Annual Conference
Year: 2002

description: One hundred and eighty five cow-calf enterprises were analyzed for production and financial performance measures that may affect profitability. Results of these analyses would indicate that for cow-calf enterprises in the Northern Great Plains, high levels of profit are a function of lower than average levels of investment, at least average levels of biological production (with particular attention paid to measures of weaning and pregnancy percentage), achieved with lower than average total expenses, and higher than average market values for calves produced. Neither high nor low levels of production, geographical region, size of operation, or year were factors that explained differences in profitability. The levels of profitability measured as return on assets (ROA) in the High Profit group are competitive with opportunities available in other sectors of the economy. The profit levels in the Medium and Low Profit groups are not competitive, and the long-term sustainability of the operations in these groups would be difficult without other sources of income and investment.
description: American Association of Bovine Practitioners Proceedings of the Annual Conference, 2002
Body Temperature in Feedlot Cattle
Creators: name: Madler, Terry L.
Publisher: name: American Association of Bovine Practitioners  Proceedings of the Annual Conference
Year: 2002

description: Body temperature is often used as an indicator of animal health status. In addition, body temperature can be used as a measure of heat stress, which occurs during the summer months and significantly impacts cattle performance and well-being. In a series of heat stress management and handling studies, tympanic temperatures (TT), an indicator of body temperature, were obtained in unrestrained feedlot cattle. In management studies, restricting feed intake to 85% of ad libitum lowered TT approximately 0.9 °F (0.5 °C), even after the period of feed restriction ended. Sprinkling feedlot surfaces was more effective in cooling cattle if sprinkling was done in the morning versus in the afternoon. Also, during hot days, TT of black-hided cattle can be over 0.9 °F (0.5 °C) greater than TT of white-hided cattle. In handling studies, moving cattle through working facilities requires an expenditure of energy causing an elevation of average body temperature between 0.5 and 1.4 °F (0.3 and 0.8 °C), depending on the ambient conditions. Effects of cattle movement and handling on body temperature needs to be taken into account when evaluating animal health studies. In addition, strategies designed to reduce the detrimental effects of heat stress while maintaining animal productivity need to be implemented. Furthermore, minimal handling of cattle during hot days is recommended for promoting animal well-being and comfort.
description: American Association of Bovine Practitioners Proceedings of the Annual Conference, 2002
Observations of Management Intensive Grazing and Forage Management
Creators: name: Lubben, Dave
Publisher: name: American Association of Bovine Practitioners  Proceedings of the Annual Conference
Year: 2002

description: Management Intensive Grazing is a tool we have developed over the years to harvest forages on our 1400-acre farming operation. Our family-owned corporation consists of my father and one employee, and includes 400 acres in corn, 400 acres in soybeans, 160 acres in hay and 500 acres in pasture. We have 220 beef cows and a 400-head finishing feedlot. Since adopting Management Intensive Grazing in 1989, it has evolved into an integral part of our operation. Today we have 12 major paddocks subdivided into 50 smaller paddocks, through which our 220 cows are rotated in four to five cycles.
description: American Association of Bovine Practitioners Proceedings of the Annual Conference, 2002
Relationship of Polyarthritis and Respiratory Disease in Cattle
Creators: name: Clark, Ted
Publisher: name: American Association of Bovine Practitioners  Proceedings of the Annual Conference
Year: 2002

description: Nearly 15 years' experience with a chronic pneumonia and polyarthritis syndrome (CPPS) in western Canadian feedlots is described. Emphasis in this presentation is on the postmortem and laboratory diagnosis of CPPS. Mycoplasma bovis is the most consistent etiologic agent isolated, but in the author's experience and opinion, chronic primary BVDV infection likely plays a significant role in predisposing to this antibiotic-unresponsive infectious disease problem. The syndrome appears to be a problem throughout North America and is an increasing problem in some dairy herds as well. The Haemophilus somnus disease complex (HSDC) is a less-common cause of concurrent respiratory and joint infections and is much simpler to diagnose.
description: American Association of Bovine Practitioners Proceedings of the Annual Conference, 2002
Carcass Disposal by Composting
Creators: name: Kube, John
Publisher: name: American Association of Bovine Practitioners  Proceedings of the Annual Conference
Year: 2002

description: Composting is an acceptable method of disposal of cattle carcasses. Composting requires appropriate carbon:nitrogen mix (-30:1), moisture (50-60%), porosity (35-45% open spaces), and temperature (130-150°F) to be successful. This paper describes a procedure used for approximately four years to successfully compost cattle. Adult (-1200 lb) intact cattle carcasses should be placed in a compost windrow for at least 60 days to assure adequate heat production and degradation of carcass before turning, mixing or grinding. Composted intact cattle can be ready for field application in approximately 12 months. Larger bones should be 'recycled' back into more compost for complete deterioration. Grinding of fresh carcasses or carcasses composted at least 60 days could reduce compost time to approximately 6 months and will eliminate major bone structure.
description: American Association of Bovine Practitioners Proceedings of the Annual Conference, 2002
Optimizing Reproductive Efficiency in the Beef Herd
Creators: name: Horstman, L. A.
Publisher: name: American Association of Bovine Practitioners  Proceedings of the Annual Conference
Year: 2002

description: It is generally accepted that improving the fertility of a beef herd has the greatest potential for increased profitability. Optimum is a term used to define the best or most favorable condition, degree or amount for a particular situation.18 Therefore, optimizing rather than maximizing reproductive efficiency offers the greatest potential for increased profitability in the beef herd. Maximizing reproductive efficiency and attaining a 100 percent conception rate on a yearly basis may be attainable, but the input costs necessary to attain this rate may not be justified from an economic standpoint. This paper is not meant to be an all-inclusive review of methods to improve reproductive efficiency; rather, methods to increase inherent fertility and environmental factors that play key roles in fertility will be discussed.
description: American Association of Bovine Practitioners Proceedings of the Annual Conference, 2002
Management Guidelines During Harvest and Storage of Silage
Creators: name: Kung, Limin
name: Neylon, Jeanne
Publisher: name: American Association of Bovine Practitioners  Proceedings of the Annual Conference
Year: 2002

description: Management techniques during harvest and storage can have marked effects on the quality of forages stored as silage. Wilting to correct moistures and chopping forages to recommended particle lengths will help during the silo packing process. High cutting of corn silage may be an option for some producers to consider in the future. However, no recommendations can be made until more research is completed. Mechanical processing of corn silage can help to improve its nutritive value by improving starch and fiber digestion. Rapid packing to recommended densities and excluding air from the forage mass stimulates a more optimal fermentation in the silo. To help with the ensiling process, microbial inoculation encourages a more efficient fermentation. When forages are drier than 40% DM, inoculants are more effective if applied in a liquid form. All silage additives should be added such that they are distributed evenly throughout the forage mass. Covering bunk and pile silos with plastic is a cost efficient mechanism to save nutrients during storage. Finally, good feedout and silo face management can also help to maintain silages with a high nutritive value.
description: American Association of Bovine Practitioners Proceedings of the Annual Conference, 2002
Protocol based on compressed sensing for high-speed authentication and cryptographic key distribution over a multiparty optical network
Creators: name: Yu, Wen-Kai
name: Li, Shen
name: Yao, Xu-Ri
name: Liu, Xue-Feng
name: Wu, Ling-An
name: Zhai, Guang-Jie
Publisher: name: arXiv
Year: 2013
Subjects: subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present a protocol for the amplification and distribution of a one-time-pad cryptographic key over a point-to-multipoint optical network based on computational ghost imaging (GI) and compressed sensing (CS). It is shown experimentally that CS imaging can perform faster authentication and increase the key generation rate by an order of magnitude compared with the scheme using computational GI alone. The protocol is applicable for any number of legitimate user, thus, the scheme could be used in real intercity networks where high speed and high security are crucial.
description: 15 pages, 5 figures. To appear in Applied Optics
Incorporating Consulting Into Veterinary Practice
Creators: name: Tyler, Donald H.
Publisher: name: American Association of Bovine Practitioners  Proceedings of the Annual Conference
Year: 2002

description: Our advice is important to every operation for which we provide consultation. Helping our clients make the right decision is not solely dependent on our ability to provide a logical analysis of all the factors that affect the current situation, but also on our ability to show the value, personal benefits and possible ramifications of utilizing the advice. The best advice possible has no value ifwe cannot help our clients understand it and make timely decisions concerning the welfare of their operation. In my work in advising clients in the area of personnel management, manager coaching and professional development, transfer of the business to the next generation, and achieving higher production goals, it has become extremely important for me to help owners and managers alike make tough decisions. Though they understand the logic involved in the decision, emotion sometimes clouds the process and evokes hesitation. Many times our clients know that they must make a change, but tradition, habit, fear of failure and a natural resistance to change get in the way. This hesitation is only exacerbated by the emotions of depression, confusion and grief from extended financial distress. An advisory methodology that incorporates an appreciation for these factors with an understanding of the emotional implications will provide greater success. Additionally, this appreciation will enhance a sense of camaraderie among all the decision-makers involved in the process.
description: American Association of Bovine Practitioners Proceedings of the Annual Conference, 2002
NYSCHAP
Creators: name: Ellis, Roger G.
Publisher: name: American Association of Bovine Practitioners  Proceedings of the Annual Conference
Year: 2002

description: The New York State Cattle Health Assurance Program (NYSCHAP) is a voluntary program of the Division of Animal Industry of the New York State Department of Agriculture and Markets that creates a team including the producer, herd veterinarian, government veterinarians, universities, extension and agricultural related businesses. The team gathers history, current facts, goals, and concerns as well as performs a risk assessment of the animal production unit. From this information a mutually discussed and agreed upon herd plan is developed incorporating "best management practices" to minimize risk, enhance production and performance as well as address environmental issues. The herd becomes a NYSCHAP Herd and the plan is reviewed regularly by the herd veterinarian and annually by the team.
description: American Association of Bovine Practitioners Proceedings of the Annual Conference, 2002
Cauchy problems for Lorentzian manifolds with special holonomy
Creators: name: Baum, Helga
name: Leistner, Thomas
name: Lischewski, Andree
Publisher: name: arXiv
Year: 2014
Subjects: subject: Differential Geometry (math.DG)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: Primary 53C50, 53C27, Secondary 53C44, 35A10, 83C05

description: On a Lorentzian manifold the existence of a parallel null vector field implies certain constraint conditions on the induced Riemannian geometry of a space-like hypersurface. We will derive these constraint conditions and, conversely, show that every real analytic Riemannian manifold satisfying the constraint conditions can be extended to a Lorentzian manifold with a parallel null vector field. Similarly, every parallel null spinor on a Lorentzian manifold induces an imaginary generalised Killing spinor on a space-like hypersurface. Then, based on the fact that a parallel spinor field induces a parallel vector field, we can apply the first result to prove: every real analytic Riemannian manifold carrying a real analytic, imaginary generalised Killing spinor can be extended to a Lorentzian manifold with a parallel null spinor. Finally, we give examples of geodesically complete Riemannian manifolds satisfying the constraint conditions.
description: 26 pages
Association of Prepartum Plasina Non-esterified Fatty Acid Concentration with Retained Placenta in Multiparous Holstein Cows
Creators: name: Conner, T.
name: Herdt, T. H.
name: Neuder, L.
Publisher: name: American Association of Bovine Practitioners  Proceedings of the Annual Conference
Year: 2001

description: Nutritional management of dairy cows during the dry period influences risk of peripartum disease. Means of rapidly monitoring nutritional status and the effectiveness of prepartum diets, prior to the development of disease, are needed by the dairy industry. Plasma nonesterified fatty acid (NEFA) concentration is a potential means of monitoring energy status in late gestation cows. High plasma NEFA concentration is associated positively with the incidence of peripartum disease dairy cows.1,3 The objective of this project was to determine, via multivariate analysis, the relationship between prepartum plasma NEFA concentration and risk of retained placenta (RP) in dairy cows.
description: American Association of Bovine Practitioners Proceedings of the Annual Conference, 2001
Rendering Farm Mortalities
Creators: name: Kirstein, Dave
Publisher: name: American Association of Bovine Practitioners  Proceedings of the Annual Conference
Year: 2002

description: Service charges for the collection and rendering of farm/feedlot cattle mortalities have become common practice and have increased most notably in the past three years. The loss of cattle by-product value is primarily responsible for this trend. Further loss of byproduct value is anticipated following the implementation of rules that are currently being proposed by the USDA to restrict additional cattle by-products from the food/feed chain. However, the collection and rendering of cattle mortalities will most likely remain the most appropriate environmental, biosecure and traceable means of disposal. Therefore, it is important to handle cattle mortalities in a manner that optimizes their remaining value. A number of practices that veterinarians and their clients perform can have a substantial impact upon the cattle by-product value. Cooperation with local renderers regarding these practices can help stabilize future disposal fees.
description: American Association of Bovine Practitioners Proceedings of the Annual Conference, 2002
Explicit ambient metrics and holonomy
Creators: name: Anderson, Ian M.
name: Leistner, Thomas
name: Nurowski, Pawel
Publisher: name: arXiv
Year: 2015
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: Primary: 53C29, 53A30, secondary: 53C50

description: We present three large classes of examples of conformal structures for which the equations for the Fefferman-Graham ambient metric to be Ricci-flat are linear PDEs, which we solve explicitly. These explicit solutions enable us to discuss the holonomy of the corresponding ambient metrics. Our examples include conformal pp-waves and, more importantly, conformal structures that are defined by generic rank 2 and 3 distributions in respective dimensions 5 and 6. The corresponding explicit Fefferman-Graham ambient metrics provide a large class of metrics with holonomy equal to the exceptional non-compact Lie group $\mathbf{G}_2$ as well as ambient metrics with holonomy contained in $\mathbf{Spin}(4,3)$.
description: 30 pages; in Section 4 of v2 the results about ambient metrics for Bryant's conformal structures are significantly generalized
ARNOLD HARTLEY GIBSON: Hydraulics professor and textbook author
Creators: name: Hager, Willi H.
Publisher: name: ETH Zurich
Year: 2022
Subjects: experimentation
history of hydraulics
hydraulic laboratory
Manchester University
textbook

description: The United Kingdom was the leading nation in the 19th century, then the British Empire. Despite this fact, hydraulic engineering was not a main concern. Scientists rather worked in maritime hydraulics and naval architecture. In all the above three topics, textbooks were not really available, because both engineers and scientists rather published their works in scientific journals. Gibson, an indirect successor of Osborne Reynolds at the University of Manchester, was the exception. His text ‘Hydraulics and its applications’ summarizes the widespread material both in hydraulic engineering and in hydraulic machinery. The purpose of this present work is to highlight both this textbook and his other writings, together with his biography, because he appears to have been largely forgotten today. Gibson was indeed an exceptional personality, who has had qualities not only in technical matters, but also in human relationships, particularly towards his students and collaborators. A British gentleman of the past century thus will be revitalized.
Single-pixel ghost microscopy based on compressed sensing and complementary modulation
Creators: name: Yu, Wen-Kai
name: Yao, Xu-Ri
name: Liu, Xue-Feng
name: Li, Long-Zhen
name: Wu, Ling-An
name: Zhai, Guang-Jie
Publisher: name: arXiv
Year: 2015
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: An experiment demonstrating single-pixel single-arm complementary compressive microscopic ghost imaging based on a digital micromirror device (DMD) has been performed. To solve the difficulty of projecting speckles or modulated light patterns onto tiny biological objects, we instead focus the microscopic image onto the DMD. With this system, we have successfully obtained a magnified image of micron-sized objects illuminated by the microscope's own incandescent lamp. The image quality of our scheme is more than an order of magnitude better than that obtained by conventional compressed sensing with the same total sampling rate, and moreover, the system is robust against intensity instabilities of the light source and may be used under very weak light conditions. Since only one reflection direction of the DMD is used, the other reflection arm is left open for future infrared light sampling. This represents a big step forward toward the practical application of compressive microscopic ghost imaging in the biological and material science fields.
description: 10 pages, 5 figures
New relations between $G_2$-geometries in dimensions 5 and 7
Creators: name: Leistner, Thomas
name: Nurowski, Pawel
name: Sagerschnig, Katja
Publisher: name: arXiv
Year: 2016
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics

description: There are two well-known parabolic split $G_2$-geometries in dimension five, $(2,3,5)$-distributions and $G_2$-contact structures. Here we link these two geometries with yet another $G_2$-related contact structure, which lives on a seven-manifold. We present a natural geometric construction of a Lie contact structure on a seven-dimensional bundle over a five-manifold endowed with a $(2,3,5)$-distribution. For a class of distributions the induced Lie contact structure is constructed explicitly and we determine its symmetries. We further study the relation between the canonical normal Cartan connections associated with the two structures. In particular, we show that the Cartan holonomy of the induced Lie contact structure reduces to $G_2$. Moreover, the curved orbit decomposition associated with a $\mathrm{G}_2$-reduced Lie contact structure on a seven-manifold is discussed. It is shown that in a neighbourhood of each point on the open curved orbit the structure descends to a $(2,3,5)$-distribution on a local leaf space, provided an additional curvature condition is satisfied. The closed orbit carries an induced $G_2$-contact structure.
description: We changed abstract a bit, and correctly defined the $G_2$ contact structure
Poster_5G International Standardisation efforts from EU experts: Insights from StandICT 2023 funded fellows
Creators: name: de Majo, Claudio
name: Giuffrida, Maria
Publisher: name: Zenodo
Year: 2024
Subjects: 5G
Standardisation

description: This poster presents results from the conference paper exploring the contributions to European and global 5G standardisation, drawing from the StandICT.eu 2023 project.
An Active Stabilizing Assistant System for a Bicycle: Modeling and Control Strategies
Creators: name: Chih-Keng Chen
Publisher: name: figshare
Year: 2016
Subjects: subject: Mechanical Engineering
subject: FOS: Mechanical engineering
subject: 90602 Control Systems, Robotics and Automation
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: In this study, a design of an active stabilizing assistant system (ASAS) is proposed. Based on this design, a nonlinear model of the assisted bicycle with a rider is developed. This nonlinear model consists of 14 degree of freedom with the wheels are assumed as thin disks. To control the system, two model predictive controllers (MPCs) have been developed. Where the first MPC is to simulate the rider’s behaviors and the second one is used to control the ASAS. In order to evaluate the performance of the ASAS, comparisons between the assisted bicycle and a normal bicycle are discussed in four cases of simulation. The results show that the ASAS can help riders to stabilize the bike with better performance
The weights of simple modules in Category $\mathscr{O}$ for Kac-Moody algebras
Creators: name: Dhillon, Gurbir
name: Khare, Apoorva
Publisher: name: arXiv
Year: 2016
Subjects: subject: Representation Theory (math.RT)
subject: Quantum Algebra (math.QA)
subject: FOS: Mathematics
subject: 17B10 (Primary), 17B67, 22E47, 17B37, 20G42 (Secondary)

description: We give the first positive formulas for the weights of every simple highest weight module $L(λ)$ over an arbitrary Kac-Moody algebra. Under a mild condition on the highest weight, we also express the weights of $L(λ)$ as an alternating sum similar to the Weyl-Kac character formula. To obtain these results, we show the following data attached to a highest weight module are equivalent: (i) its integrability, (ii) the convex hull of its weights, (iii) the Weyl group symmetry of its character, and (iv) when a localization theorem is available, its behavior on certain codimension one Schubert cells. We further determine precisely when the above datum determines the weights themselves. Moreover, we use condition (iv) to relate localizations of the convex hull of the weights with the introduction of poles of the corresponding $D$-module on certain divisors, which answers a question of Brion. Many of these results are new even in finite type. We prove similar assertions for highest weight modules over a symmetrizable quantum group.
description: 36 pages, no figures. Final form, to appear in Journal of Algebra
Asymptotic shape optimization for Riesz means of the Dirichlet Laplacian over convex domains
Creators: name: Larson, Simon
Publisher: name: arXiv
Year: 2016
Subjects: subject: Spectral Theory (math.SP)
subject: Analysis of PDEs (math.AP)
subject: Optimization and Control (math.OC)
subject: FOS: Mathematics
subject: 35P15, 47A75, 49Q10

description: For $Ω\subset \mathbb{R}^n$, a convex and bounded domain, we study the spectrum of $-Δ_Ω$ the Dirichlet Laplacian on $Ω$. For $Λ\geq0$ and $γ\geq 0$ let $Ω_{Λ, γ}(\mathcal{A})$ denote any extremal set of the shape optimization problem $$ \sup\{ \mathrm{Tr}(-Δ_Ω-Λ)_-^γ: Ω\in \mathcal{A}, |Ω|=1\}, $$ where $\mathcal{A}$ is an admissible family of convex domains in $\mathbb{R}^n$. If $γ\geq 1$ and $\{Λ_j\}_{j\geq1}$ is a positive sequence tending to infinity we prove that $\{Ω_{Λ_j, γ}(\mathcal{A})\}_{j\geq1}$ is a bounded sequence, and hence contains a convergent subsequence. Under an additional assumption on $\mathcal{A}$ we characterize the possible limits of such subsequences as minimizers of the perimeter among domains in $\mathcal{A}$ of unit measure. For instance if $\mathcal{A}$ is the set of all convex polygons with no more than $m$ faces, then $Ω_{Λ, γ}$ converges, up to rotation and translation, to the regular $m$-gon. This is a revised version of the paper published in the Journal of Spectral Theory (2019) which has been updated in accordance with an erratum published in 2021. The results of the paper remain unchanged, but the proofs of Theorem 2.4 and Corollary 5.3 have been amended.
description: This is a revised version of the paper published in J. Spectr. Theory (2019) which has been updated in accordance with an erratum published in 2021
Machine learning based multipath mitigation for high-precision GNSS data processing
Creators: name: Pan, Yuanxin
name: Möller, Gregor
name: Hohensinn, Roland
name: Soja, Benedikt
Publisher: name: ETH Zurich
Year: 2022

description: Multipath is the main unmodeled error source hindering high-precision GNSS (Global Navigation Satellite System) data processing. Classical multipath mitigation methods, such as sidereal filtering (SF) and multipath hemispherical map (MHM), have certain disadvantages: they are either too complicated for implementation or not effective enough for multipath mitigation. In this study, we demonstrate that machine learning (ML) based models, such as random forest, can overcome these drawbacks by spatial interpolation over sky map and thus mitigate multipath effectively. 30 days of 1 Hz geodetic grade GPS data as well as 6 days of low-cost data are used to train and test the ML models. Based on a series of test cases, the best number of days for model training and the validity period for the models are discussed in this contribution. For quantification, the multipath reduction rate and kinematic positioning precision are computed using different ML models and compared to those derived from SF and MHM. The statistical results show that the XGBoost ML model can achieve higher multipath reduction rates compared to SF and MHM, especially for pseudorange measurements, which is important for low-cost devices. It reduces the multipath by 48% and 55% for pseudorange and carrier phase measurements, respectively, and outperforms SF (40% and 52%) and MHM (37% and 49%). The positioning precision when using different multipath models is similar, with differences of less than 1 mm. We conclude that the ML based multipath mitigation method is effective and easy-to-use, which can be applied under real-time scenarios.
description: EGUsphere
One-dimensional self-assembly of perylene-diimide dyes by unidirectional transit of zeolite channel openings
Creators: name: Tabacchi, Gloria
name: Gion Calzaferri
name: Fois, Ettore
Publisher: name: figshare
Year: 2016
Subjects: subject: 30301 Chemical Characterisation of Materials
subject: FOS: Chemical sciences
subject: 39999 Chemical Sciences not elsewhere classified
subject: 30602 Chemical Thermodynamics and Energetics
subject: 30603 Colloid and Surface Chemistry
subject: Computational Chemistry
subject: Molecular Physics
subject: 30302 Nanochemistry and Supramolecular Chemistry
subject: 30699 Physical Chemistry not elsewhere classified
subject: 30304 Physical Chemistry of Materials
subject: 30505 Physical Organic Chemistry
subject: 30701 Quantum Chemistry
subject: Supramolecular Chemistry
subject: 30306 Synthesis of Materials
subject: 30799 Theoretical and Computational Chemistry not elsewhere classified
subject: 30307 Theory and Design of Materials
subject: 30607 Transport Properties and Non-equilibrium Processes
subject: 30206 Solid State Chemistry
subject: Computational Physics
subject: 29902 Complex Physical Systems
subject: FOS: Physical sciences
subject: Condensed Matter Physics
subject: 20499 Condensed Matter Physics not elsewhere classified
subject: 20403 Condensed Matter Modelling and Density Functional Theory
subject: 20504 Photonics, Optoelectronics and Optical Communications
subject: 29999 Physical Sciences not elsewhere classified
subject: 20406 Surfaces and Structural Properties of Condensed Matter
subject: Thermodynamics
subject: 100703 Nanobiotechnology
subject: FOS: Nanotechnology
subject: 100705 Nanoelectronics
subject: 100706 Nanofabrication, Growth and Self Assembly
subject: 100708 Nanomaterials
subject: 100709 Nanomedicine
subject: 100712 Nanoscale Characterisation
subject: 100799 Nanotechnology not elsewhere classified

description: Open access article, published in:Chem. Commun., 2016,52, 11195-11198DOI: 10.1039/C6CC05303C
Efficient phase retrieval based on dark fringe recognition with an ability of bypassing invalid fringes
Creators: name: Yu, Wen-Kai
name: Xiong, An-Dong
name: Yao, Xu-Ri
name: Zhai, Guang-Jie
name: Zhao, Qing
Publisher: name: arXiv
Year: 2016
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Optics (physics.optics)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: This paper discusses the noisy phase retrieval problem: recovering a complex image signal with independent noise from quadratic measurements. Inspired by the dark fringes shown in the measured images of the array detector, a novel phase retrieval approach is proposed and demonstrated both theoretically and experimentally to recognize the dark fringes and bypass the invalid fringes. A more accurate relative phase ratio between arbitrary two pixels is achieved by calculating the multiplicative ratios (or the sum of phase difference) on the path between them. Then the object phase image can be reconstructed precisely. Our approach is a good choice for retrieving high-quality phase images from noisy signals and has many potential applications in the fields such as X-ray crystallography, diffractive imaging, and so on.
description: 14 pages, 5 figures
Hyperbolic evolution equations, Lorentzian holonomy, and Riemannian generalised Killing spinors
Creators: name: Leistner, Thomas
name: Lischewski, Andree
Publisher: name: arXiv
Year: 2017
Subjects: subject: Differential Geometry (math.DG)
subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 53C50, 53C27, 53C29 (Primary), 53C26, 53C44, 35L02, 35L10, 83C05 (Secondary)

description: We prove that the Cauchy problem for parallel null vector fields on smooth Lorentzian manifolds is well posed. The proof is based on the derivation and analysis of suitable hyperbolic evolution equations given in terms of the Ricci tensor and other geometric objects. Moreover, we classify Riemannian manifolds satisfying the constraint conditions for this Cauchy problem. It is then possible to characterise certain holonomy reductions of globally hyperbolic manifolds with parallel null vector in terms of flow equations for Riemannian special holonomy metrics. For exceptional holonomy groups these flow equations have been investigated in the literature before in other contexts. As an application, the results provide a classification of Riemannian manifolds admitting imaginary generalised Killing spinors. We will also give new local normal forms for Lorentzian metrics with parallel null spinor in any dimension.
description: 39 pages, typos corrected and minor modifications in version 2