A Motion compensated filtering approach to remove sunlight flicker in shallow water images

A common problem in video surveys in very shallow waters is the presence of strong light fluctuations, due to sun light refraction. Refracted sunlight casts fast moving patterns, which can significantly degrade the quality of the acquired data. Motivated by the growing need to improve the quality of shallow water imagery, we propose a method to remove sunlight patterns in video sequences. The method exploits the fact that video sequences allow several observations of the same area of the sea floor, over time. It is based on computing the image difference between a given reference frame and the temporal median of a registered set of neighboring images. A key observation is that this difference will have two components with separable spectral content. One is related to the illumination field (lower spatial frequencies) and the other to the registration error (higher frequencies). The illumination field, recovered by lowpass filtering, is used to correct the reference image. In addition to removing the sunflickering patterns, an important advantage of the approach is the ability to preserve the sharpness in corrected image, even in the presence of registration inaccuracies. The effectiveness of the method is illustrated in image sets acquired under strong camera motion containing non-rigid benthic structures. The results testify the good performance and generality of the approach

Bifurcations and chaos in single-roll natural convection with low Prandtl number

Convective flows of a small Prandtl number fluid contained in a two-dimensional cavity subject to a lateral thermal gradient are numerically studied by using different techniques. The aspect ratio (length to height) is kept at around 2. This value is found optimal to make the flow most unstable while keeping the basic single-roll structure. Two cases of thermal boundary conditions on the horizontal plates are considered: perfectly conducting and adiabatic. For increasing Rayleigh numbers we find a transition from steady flow to periodic oscillations through a supercritical Hopf bifurcation that maintains the centrosymmetry of the basic circulation. For a Rayleigh number of about ten times that of the Hopf bifurcation the system initiates a complex scenario of bifurcations. In the conductive case these include a quasiperiodic route to chaos. In the adiabatic one the dynamics is dominated by the interaction of two Neimark-Sacker bifurcations of the basic periodic solutions, leading to the stable coexistence of three incommensurate frequencies, and finally to chaos. In all cases, the complex time-dependent behavior does not break the basic, single-roll structure.

Comparació de les propietats mecàniques entre dos lots de Pinus nigra entre fusta en roll i fusta en roll amb una cara feta

El present treball busca trobar si hi ha diferències significatives entre la fusta en roll i la fusta en roll amb una cara feta per a la fusta de Pinus nigra, en la resistència mecànica, concretament en la resistència a compressió paral lela a la fibra i la resistència a flexió. També s ha buscat si es pot relacionar aquestes resistències amb un mètode no destructiu com és la velocitat d ultrasons.

A survey of potential vectors of apricot chlorotic leaf roll

A comparative survey was done in leafhopper populations captured in apricot orchards in two areas of Valencia, one with considerable natural spread of apricot chlorotic leaf roll (ACLR), and the other where such natural spread is virtually nonexistent. An identification of the leafhopper species found in the first and in the second area suggest that Neoaliturus haematoceps and/or Neoaliturus fertestratus are the potential vectors of ACLR, at least under the conditions of Valencia province. Psammotettix striatus and Austroagallia sinuata are potential secondary vextors of ACLR.

Incidence, prevalence and clinical significance of abnormal hematological indices in compensated cirrhosis.

Background & Aims: Patients with cirrhosis develop abnormal hematologic indices (HI) from multiple factors, including hypersplenism. We aimed to analyze the sequence of events and determine whether abnormal HI has prog-nostic significance. Methods: We analyzed a database of 213 subjects with compensated cirrhosis without esopha-geal varices. Subjects were followed for approximately 9 years until the development of varices or variceal bleeding or completion of the study; 84 subjects developed varices. Abnormal HI was defined as anemia at baseline (hemoglo-bin,<13.5 g/dL for men and 11.5 g/dL for women), leuko-penia (white blood cell counts,<4000/mm 3 ), or thrombo-cytopenia (platelet counts, < 150,000/mm 3 ). The primary end points were death or transplant surgery. Results: Most subjects had thrombocytopenia at baseline. Kaplan-Meier analysis showed that leukopenia occurred by 30 months (95% confidence interval, 18.5-53.6), and anemia occurred by 39.6 months (95% confidence interval, 24.1-49.9). Baseline thrombocytopenia (P .0191) and leukope-nia (P.0383) were predictors of death or transplant, after adjusting for baseline hepatic venous pressure gradient (HVPG), and Child-Pugh scores. After a median of 5 years,a significant difference in death or transplant, mortality,and clinical decompensation was observed in patients who had leukopenia combined with thrombocytopenia at base- line compared with patients with normal HI (P < .0001). HVPG correlated with hemoglobin and white blood cell count (hemoglobin, r 0.35, P < .0001; white blood cell count, r 0.31, P < .0001). Conclusions: Thrombocy-topenia is the most common and first abnormal HI to occurin patients with cirrhosis, followed by leukopenia and anemia. A combination of leukopenia and thrombocytopenia at baselin predicted increased morbidity and mortality.

Comparative study of two needle models in terms of deflection during inferior alveolar nerve block

Objectives: The purpose of this study is to determine the possible differences in deflection between two needles of same length and external gauge but with different internal gauges during truncal block of the inferior alveolar nerve. The initial working hypothesis was that greater deflection may be expected with larger internal gauge needles. Study design: Four clinicians subjected 346 patients to inferior alveolar nerve block and infiltrating anesthesia of the buccal nerve trajectory for the surgical or conventional extraction of the lower third molar. A nonautoaspirating syringe system with 2 types of needle was used: a standard 27-gauge x 35-mm needle with an internal gauge of 0.215 mm or an XL Monoprotect® 27-gauge x 35-mm needle with an internal gauge of 0.265 mm. The following information was systematically recorded for each patient: needle type, gender, anesthetic technique (direct or indirect truncal block) and the number of bone contacts during the procedure, the patient-extraction side, the practitioner performing the technique, and blood aspiration (either positive or negative). Results: 346 needles were used in total. 190 were standard needles (27-gauge x 35-mm needle with an internal gauge of 0.215 mm) and 156 were XL Monoprotect®. Incidence of deflection was observed in 49.1% of cases (170 needles) where 94 were standard needles and 76 XL Monoprotect®. Needle torsion ranged from 0º and 6º. Conclusions: No significant differences were recorded in terms of deflection and internal gauge, operator, patient-extraction side, the anesthetic technique involved and the number of bone contacts during the procedure

A Model of ethnic conflict

We present a model of conflict, in which discriminatory government policy or social intolerance is responsive to various forms of ethnic activism, including violence. It is this perceived responsiveness -captured by the probability that the government gives in and accepts a proponed change in ethnic policy- that induces individuals to mobilize in support for their cause. Yet, mobilization is costly and demonstrators have to be compensated accordingly. Individuals have to weigh their ethnic radicalism with their material well-being to determine the size of their money contribution to the cause. Our main results are: (i) a one-sided increase in radicalism or in population size increases conflict; (ii) a one-sided increase in income has ambiguous effects depending on the elasticity of contributions to income; (iii) an increase in within-group inequality increases conflict; and (iv) an increase in the correlation between ethnic radicalism and inequality also increases conflict.

Testing low-altitude infrared digital photography from a mini-UAV to retrieve information for biological conservation

Satellite remote sensing imagery is used for forestry, conservation and environmental applications, but insufficient spatial resolution, and, in particular, unavailability of images at the precise timing required for a given application, often prevent achieving a fully operational stage. Airborne remote sensing has the advantage of custom-tuned sensors, resolution and timing, but its price prevents using it as a routine technique for the mentioned fields. Some Unmanned Aerial Vehicles might provide a “third way” solution as low-cost techniques for acquiring remotely sensed information, under close control of the end-user, albeit at the expense of lower quality instrumentation and instability. This report evaluates a light remote sensing system based on a remotely-controlled mini-UAV (ATMOS-3) equipped with a color infra-red camera (VEGCAM-1) designed and operated by CATUAV. We conducted a testing mission over a Mediterranean landscape dominated by an evergreen woodland of Aleppo pine (Pinus halepensis) and (Holm) oak (Quercus ilex) in the Montseny National Park (Catalonia, NE Spain). We took advantage of state-of-the-art ortho-rectified digital aerial imagery (acquired by the Institut Cartogràfic de Catalunya over the area during the previous year) and used it as quality reference. In particular, we paid attention to: 1) Operationality of flight and image acquisition according to a previously defined plan; 2) Radiometric and geometric quality of the images; and 3) Operational use of the images in the context of applications. We conclude that the system has achieved an operational stage regarding flight activities, although with meteorological limits set by wind speed and turbulence. Appropriate landing areas can be sometimes limiting also, but the system is able to land on small and relatively rough terrains such as patches of grassland or short matorral, and we have operated the UAV as far as 7 km from the control unit. Radiometric quality is sufficient for interactive analysis, but probably insufficient for automated processing. A forthcoming camera is supposed to greatly improve radiometric quality and consistency. Conventional GPS positioning through time synchronization provides coarse orientation of the images, with no roll information.

Longer-term impacts of mentoring, educational services, and incentives to learn: evidence from a randomized trial in the United States

This paper is the first to use a randomized trial in the US to analyze the short- and long-term educational and employment impacts of an afterschool program that offered disadvantaged high-school youth: mentoring, educational services, and financial rewards with the objective to improve high-school graduation and postsecondary schooling enrollment. The short-term hefty beneficial average impacts quickly faded away. Heterogeneity matters. While encouraging results are found for younger youth, and when the program is implemented in relatively small communities of 9th graders; detrimental longlived outcomes are found for males, and when case managers are partially compensated by incentive payments and students receive more regular reminders of incentives.

Regulación de la movilidad celular por Profilina 1

Mi proyecto de tesis se basaba en el estudio del papel de profilina 1 en la formación de lamelas, para ello generamos una proteína recombinante y transducible, con el objetivo de poder modificar los niveles endógenos de profilina. Objetivos: i-caracterización bioquímica los tres sitios de union conocidos de la proteína de transducción, el sitio de unión a fosfo-inocitoles (PIP), el de unión a actina (Ac) y el de unión a poli-prolinas (PLP). ii-estudio de la polimerización in-vitro de actina - PTD4-Profilina1 iii-estudio de las proteínas componentes de lamelas inducidas por PTD4-Profilina1. Plan de trabajo: i-Para comprobar la funcionalidad los 3 sitios de unión fueron necesarias las primeras 6 semanas, ya que en primer lugar había que expresar y purificar el peptido Srv2, necesario para el ensayo de PLP. En segundo lugar, se obtuvieron los datos de las concentraciones adecuadas de lípidos para el ensayo de fosfo-inocitoles y por ultimo, se purifico la actina necesaria para el ensayo de unión a actina. Una vez establecida la funcionalidad de la proteína, se procedió a: ii-el estudio de polimerización in-vitro, que llevo 2 semanas. Demostrando que in-vitro era capaz de inhibir la polimerización de una manera similar a la endógena. Una vez terminados estos ensayos, se procedio a: iii-la caracterización inmunohistoquímica de las proteínas componentes de la lamela que fue llevado a cabo en 4 semanas. Para ello se usaron anticuerpos contra: alfa-actinina, talina, vinculina, ENA/Vasp y paxillina. Conclusiones: i-las propiedades bioquímicas de la PTD4-Profilina1 son similares a las de la profilina endógena. ii-los estudios de polimerización indican que la polimerización se produce de manera similar a la endogena. iii-los ensayos de inmunohistoquímica sugieren que, talina esta ausente y que las demás están presentes aunque en menor concentración y con otra distribución comparadas con los controles.

Structural decomposition analysis and input-output subsystems: An application to Spanish CO2 emissions

Analysis of gas emissions by the input-output subsystem approach provides detailed insight into pollution generation in an economy. Structural decomposition analysis, on the other hand, identifies the factors behind the changes in key variables over time. Extending the input-output subsystem model to account for the changes in these variables reveals the channels by which environmental burdens are caused and transmitted throughout the production system. In this paper we propose a decomposition of the changes in the components of CO2 emissions captured by an input-output subsystems representation. The empirical application is for the Spanish service sector, and the economic and environmental data are for years 1990 and 2000. Our results show that services increased their CO2 emissions mainly because of a rise in emissions generated by non-services to cover the final demand for services. In all service activities, the decomposed effects show an increase in CO2 emissions due to a decrease in emission coefficients (i.e., emissions per unit of output) compensated by an increase in emissions caused both by the input-output coefficients and the rise in demand for services. Finally, large asymmetries exist not only in the quantitative changes in the CO2 emissions of the various services but also in the decomposed effects of these changes. Keywords: structural decomposition analysis, input-output subsystems, CO2 emissions, service sector.

Definició d'un procés de gestió de projectes que compleixi amb el model d'avaluació i millora de processos CMM a Nivell 3

Aquest TFC vol fer una presentació del model CMM, presentar un sistema de gestió que cobreixi els seus requeriments a nivell 3, fer una proposta de desplegament i avaluar els costos i els beneficis de l'adopció del nou sistema de gestió per a una empresa dedicada al desenvolupament i el manteniment de programari. El resultat del treball és la memòria en si i els seus annexos.

Correction of shading effects in vision-based UUV localization

This paper describes the improvements achieved in our mosaicking system to assist unmanned underwater vehicle navigation. A major advance has been attained in the processing of images of the ocean floor when light absorption effects are evident. Due to the absorption of natural light, underwater vehicles often require artificial light sources attached to them to provide the adequate illumination for processing underwater images. Unfortunately, these flashlights tend to illuminate the scene in a nonuniform fashion. In this paper a technique to correct non-uniform lighting is proposed. The acquired frames are compensated through a point-by-point division of the image by an estimation of the illumination field. Then, the gray-levels of the obtained image remapped to enhance image contrast. Experiments with real images are presented

(Endogenous) occupational choices and job satisfaction among recent PhD recipients: evidence from Catalonia

Drawing on data from two successive cohorts of PhD graduates, this paper analyses differences in overall job satisfaction and specific job domain satisfaction among PhDs employed in different sectors four years after completing their doctorate degrees. Covariate-adjusted job satisfaction differentials suggest that, compared to faculty members, PhD holders employed outside traditional academic and research jobs are more satisfied with the pecuniary facets of their work (principally, because of higher earnings), but significantly less satisfied with the content of their job and with how well the job matches their skills (and, in the case of public sector workers, with their prospects of promotion). The evidence regarding the overall job satisfaction of the PhD holders indicates that working in the public or private sectors is associated with less work well-being, which cannot be fully compensated by the better pecuniary facets of the job. It also appears that being employed in academia or in research centres provides almost the same perceived degree of satisfaction with the job and with its four specific domains. We also take into account the endogenous sorting of PhD holders into different occupations based on latent personal traits that might be related to job satisfaction. The selectivity-corrected job satisfaction differentials reveal the importance of self-selection based on unobservable traits, and confirm the existence of a certain penalisation for working in occupations other than academia or research, which is especially marked in the case of satisfaction with job content and job-skills match. The paper presents additional interesting evidence about the determinants of occupational choice among PhD holders, highlighting the relevance of certain academic attributes (especially PhD funding and pre-and-post-doc research mobility) in affecting the likelihood of being employed in academia, in a research centre or in other public or private sector job four years after completing their doctorate programme.

How competition controls team production: The case of fishing firms

Under team production, those who monitor individual productivity areusually the only ones compensated with a residual that varies withthe performance of the team. This pattern is efficient, as is shownby the prevalence of conventional firms, except for small teams andwhen specialized monitoring is ineffective. Profit sharing in repeatedteam production induces all team members to take disciplinary actionagainst underperformers through switching and separation decisions,however. Such action provides effective self-enforcemnt when themarkets for team members are competitive, even for large teams usingspecialized monitoring. The traditional share system of fishing firmsshows that for this competition to provide powerful enough incentivesthe costs of switching teams and measuring team productivity must bebellow. Risk allocation may constrain the organizational designdefined by the use of a share system. It does not account for itsexistence, however.