763 research outputs found

    Playing Down to the Competition? Making Sense of a Golfer\u27s Frequently Used Excuse

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    Golf is a sport that continues to develop throughout the years. The development of the sport exceeds the fascinating technological advances of the clubs, balls and gadgets and has taken a new sector of people by storm. Every year golf seems to capture a new audience and more over a new generation of women have taken a liking to the sport. With all these great advances there still seems to be a question out there on why performance fluctuates so much? This fluctuation can be seen by the avid sports observer on any weekend of a PGA tour event, yearly seasons and monetary winnings lists where seldomly does a golfer rule the sport for a long time how it is often seen in other sports. Our research focuses on a mental phenomenon that causes weekend golfers some of the same stresses. Opposite of a professional golfer, weekend golfers do not know the root cause of their inconsistent play, some blame the weather, while others blame new equipment, or old equipment. With every excuse a golfer gives, one has stood out to us more than others as it takes the mental aspect of the sport to another level. “I played bad because the person I was playing against was so good, (or so bad), that it affected my play”. This excuse seems to have merit within the golfing community as the many golfers we have spoken to on this journey seem to agree with the statements. The theoretical framework this research will draw from is social learning theory and in particular the subfactor of self-efficacy, which is the degree of one’s feeling about one’s ability to accomplish his or her goals (Bandura, 1997). Does the self-efficacy of a golfer change because they are playing with a golfer of a substantial difference in skill level, and does this change cause a less than usual performance

    Polarization fluctuations in vertical cavity surface emitting lasers: a key to the mechanism behind polarization stability

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    We investigate the effects of the electron-hole spin dynamics on the polarization fluctuations in the light emitted from a vertical cavity surface emitting laser (VCSEL). The Langevin equations are derived based on a rate equation model including birefringence, dichroism, and two carrier density pools seperately coupled to right and left circular polarization. The results show that the carrier dynamics phase lock the polarization fluctuations to the laser mode. This is clearly seen in the difference between fluctuations in ellipticity and fluctuations in polarization direction. Seperate measurements of the polarization fluctuations in ellipticity and in polarization direction can therefore provide quantitative information on the non-linear contribution of the carrier dynamics to polarization stability in VCSELs.Comment: 6 pages RevTex and 3 figures, to be published in Quantum and Semiclassical Optics, minor changes to the discussion of timescale

    Pneumocephalus Following Unidentified Dural Puncture: A Case Report with an Unusual Neurological Presentation

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    Pneumocephalus is a rare consequence of epidural anesthesia, which may occur following inadvertent or unidentified dural puncture when the loss of resistance to air technique is applied to identify the epidural space. Headache is the most common symptom presented in this condition, usually with sudden onset. This case report describes an unusual presentation of diffuse pneumocephalus after an unidentified dural puncture. The patient (male, 67 years old) was submitted to epidural catheter placement for the treatment of acute exacerbation of ischemic chronic pain using loss of resistance to air technique. No cerebrospinal fluid or blood flashback was observed after needle withdrawal. Shortly after the intervention, the patient presented symptoms of lethargy, apathy, and hypophonia, which are not commonly associated with pneumocephalus. No motor or sensory deficits were detected. Cranial computed tomography showed air in the frontal horn of the left ventricle, subarachnoid space at interhemispheric fissure and basal cisterns, confirming the diagnosis of diffuse pneumocephalus. The patient remained under vigilance with oxygen therapy and the epidural catheter left in place. After 24 hours, cranial computed tomography showed air in the temporal and frontal horns of the left ventricle, with no air in the subarachnoid space. The patient presented no neurological signs or symptoms at this time. Although headache is the most common symptom presented in reported cases of pneumocephalus, this case shows the need for the clinician to be aware of other signs and symptoms that may be indicative of this condition, in order to properly diagnose and treat these patients.info:eu-repo/semantics/publishedVersio

    An approximation to technical efficiency in Spanish toll roads through a DEA approach

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    This research has an academic approach to know the relative efficiency of toll roads managed by the Administración General del Estado through a DEA approach. The global technical efficiency, local pure technical efficiency and scale efficiency were estimated. Thus, the possible reasons why there is inefficiency and as reverse it. The great majority of toll roads are not fully effective according to the DEA approach, showing a greater global efficiency, with an increase in their return to scale, with the possibility of improvements in their efficiency levels.Peer ReviewedPostprint (published version

    Polarization switching in vertical-cavity surface emitting lasers observed at constant active region temperature

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    Includes bibliographical references (page 3352).Polarization switching in gain-guided, vertical-cavity, surface-emitting lasers was studied as a function of the active region temperature. We show that polarization switching occurs even when the active region temperature is kept constant during fast pulse low duty cycle operation. This temperature independent polarization switching phenomenon is explained in terms of a recently developed model

    Control of Ground Movements for a Multi-Level-Anchored, Diaphragm Wall During Excavation

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    An excavation up to 23m deep for the Dana Farber research tower in the Longwood medical area of Boston, was supported by a permanent perimeter diaphragm wall extending into the underlying conglomerate and up to 6 levels of prestressed tiebacks anchored in the rock. The lateral earth support system was very successful in limiting wall deflections to less than ±15mm on each of the four sides of the excavation. However, ground surface settlements up to 65mm occurred on two sides and were attributed to ground losses that occurred when tiebacks were installed through overpressured sand layers at depths of 15-18m. Finite element simulations are able to describe consistently the effects of the different excavation and support sequences on each side of the project using backfigured soil properties, while surface settlements can be explained by including local ground losses within the analyses

    Transient response of vertical-cavity surface-emitting lasers of different active-region diameters

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    Includes bibliographical references (pages 614-615).The multimode dynamics of vertical-cavity surface-emitting lasers with different active-region diameters was measured under subnanosecond electrical excitation (800-ps pulse duration, 100-ps risetime). The dynamics is characterized by the delayed onset of higher order modes which have a turn-on delay that is dependent on the active-region diameter and the excitation parameters. A simple model that can be used to estimate this turn-on delay for large-area devices is presented. Polarization resolved measurements show that, under this fast excitation condition, both orthogonal polarization states are isomorphic. The influence of the observed dynamics on the relative intensity noise of these devices is also discussed

    Bases for the digital transformation of the productive sector: an exploratory study of key competencies in Peru

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    The main objective of this research is to determine the basis of the key competencies necessary to achieve the digital transformation of public and private organizations in Peru. With this objective in mind, the conceptual framework involves the definition of a digital transformation in organizations and their impact on those organizations. Secondly, the article presented the results of the exploratory fieldwork conducted through in-depth interviews with ten executives from different productive sectors and analyzed them through content analysis. From this exploratory study, it concludes that all the experts interviewed agree on: i) the urgency of initiating a digital transformation process in small, medium, and large companies; ii) the need for training in digital transformation for company employees in all functional lines, giving priority to the commercial area; and iii) investment in the implementation process starting with cybersecurity and big data due to the impact on the operational and commercial results of the companies.El objetivo principal de esta investigaci?n es determinar las bases de las competencias clave necesarias para lograr la transformaci?n digital de las organizaciones p?blicas y privadas en el Per?. Con este objetivo en mente, el marco conceptual implica la definici?n de la transformaci?n digital en las organizaciones y su impacto en las mismas. En segundo lugar, el art?culo presenta los resultados del trabajo de campo exploratorio realizado a trav?s de entrevistas en profundidad a diez ejecutivos de diferentes sectores productivos y los analiza a trav?s del an?lisis de contenido. De este estudio exploratorio se concluye que todos los expertos entrevistados coinciden en: i) la urgencia de iniciar un proceso de transformaci?n digital en las peque?as, medianas y grandes empresas; ii) la necesidad de formaci?n en transformaci?n digital para los empleados de las empresas en todas las l?neas funcionales, priorizando el ?rea comercial; y iii) la inversi?n en el proceso de implantaci?n a partir de la ciberseguridad y el big data por el impacto en los resultados operativos y comerciales de las empresas

    Virtualization of pliocene sites in the Huelva province: valuating the paleontological heritage in differentiate educative settings I

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    El patrimonio paleontológico del Plioceno de la provincia de Huelva es uno de los más importantes de España y referente europeo de moluscos de este período. Sin embargo, no existe un inventario de catalogación básica de los principales yacimientos ni de los principales grupos fósiles presentes, así como de su importancia como patrimonio natural. El presente trabajo pretende rellenar este notable vacío con una proyección tanto hacia materias preuniversitarias como universitarias, así como hacia posibles instituciones y corporaciones públicas susceptibles de utilizarlo en sus planes de ordenación. Por otro lado, se pretende que actúe como mecanismo de interconexión entre titulaciones con bajo número de alumnos de nuevo ingreso y los centros de Bachillerato, de forma que incentive una posible elección de estos Grados por los alumnos de las opciones científico-tecnológicas. También puede ser interesante para captar egresados hacia Másteres Oficiales en Patrimonio Histórico y Natural. En este sentido, se ha realizado un DVD documental sobre el patrimonio paleontológico del Plioceno de la provincia de Huelva, concretamente de las formaciones “Arenas de Huelva” y “Arenas de Bonares” desarrolladas en ambientes marinos someros y costeros durante la última etapa de evolución neógena de la cuenca. Este documental incluye una visión de conjunto de los principales yacimientos fósiles de esta edad, así como una explicación de la evolución paleogeográfica de nuestra provincia y los organismos que la han caracterizado en los últimos millones de años. Esta aportación es aplicable en el trabajo de campo de varios Grados y Posgrados universitarios y de fácil uso como material didáctico en diversas asignaturas de E.S.O. y Bachillerato. Este trabajo se ha realizado en el marco del proyecto de innovación docente (PID nº 10050) de la Universidad de Huelva.The paleontological heritage from the Neogene in the province of Huelva is one of the most important in Spain and it is considered a European reference site for the mollusk fossil record from this period. However, there are not basic inventories neither for the main sites nor the major fossil groups. Furthermore, no inventories exist about their natural heritage importance. This work aims to fill this significant gap for both pre-university and university levels, as well as to public institutions and corporations that may use it in their management plans. In addition, it is intended to act as an linking mechanism between university degrees with low number of first-year students and high school centres, in order to encourage a possible choice of these Bachelor’s degrees by scientific and technological students. It may also be interesting to catch the attention of graduates for Official Masters in Historical and Natural Heritage. In this sense, a DVD-documentary has been made about the paleontological heritage from the Pliocene in the province of Huelva, specifically from the “Arenas de Huelva” and “Arenas de Bonares” formations. These units were developed in shallow marine and coastal environments during the last stage of the Neogene evolution in the Guadalquivir Basin. This documental includes an overview of main marine fossil sites from this age and a brief explanation of the palaeogeographic evolution of the Huelva province during the last million of years. This contribution is useful for the fieldwork at Bachelor and Master Degree level and it is easy to use as teaching materials in different ESO (Obligatory Secondary Teaching) and High School subjects. This work has been support for an Innovation in Teaching Project (PID No. 10050) of the Huelva University
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