928 resultados para Synchronization capability
Resumo:
Object selection refers to the mechanism of extracting objects of interest while ignoring other objects and background in a given visual scene. It is a fundamental issue for many computer vision and image analysis techniques and it is still a challenging task to artificial Visual systems. Chaotic phase synchronization takes place in cases involving almost identical dynamical systems and it means that the phase difference between the systems is kept bounded over the time, while their amplitudes remain chaotic and may be uncorrelated. Instead of complete synchronization, phase synchronization is believed to be a mechanism for neural integration in brain. In this paper, an object selection model is proposed. Oscillators in the network representing the salient object in a given scene are phase synchronized, while no phase synchronization occurs for background objects. In this way, the salient object can be extracted. In this model, a shift mechanism is also introduced to change attention from one object to another. Computer simulations show that the model produces some results similar to those observed in natural vision systems.
Resumo:
Chaotic synchronization has been discovered to be an important property of neural activities, which in turn has encouraged many researchers to develop chaotic neural networks for scene and data analysis. In this paper, we study the synchronization role of coupled chaotic oscillators in networks of general topology. Specifically, a rigorous proof is presented to show that a large number of oscillators with arbitrary geometrical connections can be synchronized by providing a sufficiently strong coupling strength. Moreover, the results presented in this paper not only are valid to a wide class of chaotic oscillators, but also cover the parameter mismatch case. Finally, we show how the obtained result can be applied to construct an oscillatory network for scene segmentation.
Resumo:
Synchronization and chaos play important roles in neural activities and have been applied in oscillatory correlation modeling for scene and data analysis. Although it is an extensively studied topic, there are still few results regarding synchrony in locally coupled systems. In this paper we give a rigorous proof to show that large numbers of coupled chaotic oscillators with parameter mismatch in a 2D lattice can be synchronized by providing a sufficiently large coupling strength. We demonstrate how the obtained result can be applied to construct an oscillatory network for scene segmentation. (C) 2007 Elsevier B.V. All rights reserved.
Resumo:
The overall aim of this thesis has been to investigate the meaning of the capability to move in order to identify and describe this capability from the perspective of the one who moves in relation to specific movements. It has been my ambition to develop ways to explicate, and thereby open up for discussion, what might form an educational goal in the context of movements and movement activities in the school subject of physical education and health (PEH). In this study I have used a practical epistemological perspective on capability to move, a perspective that challenges the traditional distinction between mental and physical skills as well as between theoretical and practical knowledge. Movement actions, or ways of moving, are seen as expressions of knowing. In order to explore an understanding of the knowing involved in specific ways of moving, observations of actors’ ways of moving and their own experiences of moving were brought together. Informants from three different arenas took part: from PEH in upper secondary school, from athletics and from free-skiing. The results of the analyses suggest it is possible to describe practitioners’ developed knowing as a number of specific ways of knowing that are in turn related to specific ways of moving. Examples of such specific ways of moving may be discerning and modifying one’s own rotational velocity and navigating one’s (bodily) awareness. Additionally, exploring learners’ pre-knowing of a movement ‘as something’ may be fruitful when planning the teaching and learning of capability to move. I have suggested that these specific ways of knowing might be regarded as educational goals in PEH. In conducting this study, I have also had the ambition to contribute to the ongoing discussion of what ‘ability’ in the PEH context might mean. In considering specific ways of knowing in moving, the implicit and taken-for-granted meaning of ‘standards of excellence’ and ‘sports ability’can be discussed, and challenged.
Resumo:
The core concepts of CA In the theoretical framework of CA, well-being is constituted by a person’s unique way of functioning and capabilities. This means that a person's well-being is personal and involves freedom of choice which in turn means they have a number of options. Although many people may have the same resources, it is of importance to study how these resources are converted into how they function. Thus, wellbeing is about the person's freedom to achieve in general and the capabilities to function in particular (Sen, 1995). Strength of the capability approach The capability approach is a useful tool for matching objective evaluations with subjective metrics. Furthermore, although one’s individual abilities are in focus, contextual factors, and subjective perceptions and experiences, are taken into consideration. Critiques against the CA The capability approach has been criticized for being too individual-centered and not taking sufficient account to social structures in society. It is difficult to know what a person would choose to do if other options were available. Therefore, to operationalize abilities involves uncertainties.
Resumo:
Introduction Performance in cross-country skiing is influenced by the skier’s ability to continuously produce propelling forces and force magnitude in relation to the net external forces. A surrogate indicator of the “power supply” in cross-country skiing would be a physiological variable that reflects an important performance-related capability, whereas the body mass itself is an indicator of the “power demand” experienced by the skier. To adequately evaluate an elite skier’s performance capability, it is essential to establish the optimal ratio between the physiological variable and body mass. The overall aim of this doctoral thesis was to investigate the importance of body-mass exponent optimization for the evaluation of performance capability in cross-country skiing. Methods In total, 83 elite cross-country skiers (56 men and 27 women) volunteered to participate in the four studies. The physiological variables of maximal oxygen uptake (V̇O2max) and oxygen uptake corresponding to a blood-lactate concentration of 4 mmol∙l-1 (V̇O2obla) were determined while treadmill roller skiing using the diagonal-stride technique; mean oxygen uptake (V̇O2dp) and upper-body power output (Ẇ) were determined during double-poling tests using a ski-ergometer. Competitive performance data for elite male skiers were collected from two 15-km classical-technique skiing competitions and a 1.25-km sprint prologue; additionally, a 2-km double-poling roller-skiing time trial using the double-poling technique was used as an indicator of upper-body performance capability among elite male and female junior skiers. Power-function modelling was used to explain the race and time-trial speeds based on the physiological variables and body mass. Results The optimal V̇O2max-to-mass ratios to explain 15-km race speed were V̇O2max divided by body mass raised to the 0.48 and 0.53 power, and these models explained 68% and 69% of the variance in mean skiing speed, respectively; moreover, the 95% confidence intervals (CI) for the body-mass exponents did not include either 0 or 1. For the modelling of race speed in the sprint prologue, body mass failed to contribute to the models based on V̇O2max, V̇O2obla, and V̇O2dp. The upper-body power output-to-body mass ratio that optimally explained time-trial speed was Ẇ ∙ m-0.57 and the model explained 63% of the variance in speed. Conclusions The results in this thesis suggest that V̇O2max divided by the square root of body mass should be used as an indicator of performance in 15-km classical-technique races among elite male skiers rather than the absolute or simple ratio-standard scaled expression. To optimally explain an elite male skier’s performance capability in sprint prologues, power-function models based on oxygen-uptake variables expressed absolutely are recommended. Moreover, to evaluate elite junior skiers’ performance capabilities in 2-km double-poling roller-skiing time trials, it is recommended that Ẇ divided by the square root of body mass should be used rather than absolute or simple ratio-standard scaled expression of power output.
Resumo:
In the field of Information and Communication Technologies for Development (ICT4D) ICT use in education is well studied. Education is often seen as a pre-requisite for development and ICTs are believed to aid in education, e.g. to make it more accessible and to increase its quality. In this paper we study the access and use of ICT in a study circle (SC) education program in the south coast of Kenya. The study is qualitative reporting results based on interviews and observations with SC participants, government officers and SC coordinators and teachers. The study builds on the capability approach perspective of development where individuals’ opportunities and ability to live a life that they value are focused. The aim of the study is to investigate the capability outcomes enabled through the capability inputs access and use of ICT in education as well as the factors that enabled and/or restricted the outcomes. Findings show that many opportunities have been enabled such as an increase in the ability to generate an income, learning benefits, community development and basic human development (e.g. literacy and self-confidence). However, conversion factors such as a poorly developed infrastructure and poor IT literacy prevent many of the individuals from taking full advantage of the ICT and the opportunities it enables.
Resumo:
Apesar de o CMMI (Capability Maturity Model Integration) prover uma cobertura mais detalhada do ciclo de vida dos produtos que o uso isolado de outros processos de melhoria, ainda assim não pode ser visto como uma metodologia pronta para ser utilizada pelas organizações. Cada organização deve mapear as áreas de processo do nível CMMI desejado (caso a opção seja a representação por estágios, como veremos adiante) à sua metodologia, aos seus métodos e técnicas de desenvolvimento de produtos e sistemas, levando também em consideração os objetivos de negócio da organização. Tanto o CMMI como as demais normas e modelos de qualidade, dizem “o que” e não “como” fazer. Determinar este “como” é um trabalho adicional bastante grande que as organizações devem realizar quando da adoção destas normas. Para isto, normalmente as organizações buscam no mercado empresas de consultoria que possuem experiência na área. Essas consultorias são bastante indicadas porque aumentam significativamente a qualidade e a velocidade dos resultados. Este trabalho pretende facilitar as organizações interessadas na implementação de um modelo de qualidade, fornecendo descrições sobre alguns dos modelos de qualidade mais utilizados atualmente, bem como modelos de processos, guias e formulários que podem ser utilizados diretamente ou como uma base para a implementação do modelo desejado. Embora se aplique à implementação de qualquer modelo de qualidade, mais especificamente, este trabalho destina-se a auxiliar organizações que visem implementar o modelo CMMI nível 2 (doravante usaremos também a abreviação CMMI-N2). Para tanto, descreve de forma mais detalhada este modelo e fornece um caminho para a implementação do mesmo, incluindo a descrição de um processo mínimo de desenvolvimento de software, com base no RUP (Rational Unified Process) e o uso de um modelo de ciclo de vida de melhoria de processos, o IDEAL. Neste trabalho, propõe-se que seja utilizado o modelo IDEAL para a implementação do modelo de qualidade devido ao fato de este modelo ter sido concebido originalmente como um modelo de ciclo de vida para melhoria de processos de software com base no SW-CMM (Capability Maturity Model for Software). Associado a esse modelo, é sugerido que se utilize algumas técnicas e processos de gerência de projetos para cada área de processo do CMMI-N2, visando implantar cada área de processo através de um projeto. Para a implementação são propostos guias, modelos (formulários) de implementação e uma tabela que mapeia todas as áreas de processo do CMMI-N2, seus objetivos, práticas, produtos de trabalho e as ferramentas associadas.
Resumo:
Apesar de diversos modelos assumirem que os preços não se ajustam sincronizadamente, tanto a evidência empírica quanto a teórica são ambíguas. Este trabalho tem por objetivo identificar o comportamento dos reajustes de preço, analisando uma extensa base de dados brasileira. Foi encontrada uma evidência de escalonamento, mas quanto mais agregado são os dados, mais perto da sincronização perfeita eles estão. A economia brasileira também mostrou um alto grau de heterogeneidade, tanto na frequência quanto na sincronização dos ajustes de preço entre os produtos, as quais ainda variam com a taxa de inflação.
Resumo:
This paper characterizes humic substances (HS) extracted from soil samples collected in the Rio Negro basin in the state of Amazonas, Brazil, particularly investigating their reduction capabilities towards Hg(II) in order to elucidate potential mercury cycling/volatilization in this environment. For this reason, a multimethod approach was used, consisting of both instrumental methods (elemental analysis, EPR, solid-state NMR, FIA combined with cold-vapor AAS of Hg(0)) and statistical methods such as principal component analysis (PCA) and a central composite factorial planning method. The HS under study were divided into groups, complexing and reducing ones, owing to different distribution of their functionalities. The main functionalities (cor)related with reduction of Hg(II) were phenolic, carboxylic and amide groups, while the groups related with complexation of Hg(II) were ethers, hydroxyls, aldehydes and ketones. The HS extracted from floodable regions of the Rio Negro basin presented a greater capacity to retain (to complex, to adsorb physically and/or chemically) Hg(II), while nonfloodable regions showed a greater capacity to reduce Hg(II), indicating that HS extracted from different types of regions contribute in different ways to the biogeochemical mercury cycle in the basin of the mid-Rio Negro, AM, Brazil. (c) 2007 Published by Elsevier B.V.
Resumo:
The present study investigated how the timing of the administration of estradiol benzoate (EB) impacted the synchronization of ovulation in fixed-time artificial insemination protocols of cattle. To accomplish this, two experiments were conducted, with EB injection occurring at different times: at withdrawal of the progesterone-releasing (N) intravaginal device or 24 h later. The effectiveness of these times was compared by examining ovarian follicular dynamics (Experiment 1, n = 30) and conception rates (Experiment 2, n = 504). In Experiment 1, follicular dynamics was performed in 30 Nelore cows (Bos indicus) allocated into two groups. on a random day of the estrous cycle (Day 0), both groups received 2 mg of EB i.m. and a P4-releasing intravaginal device, which was removed on Day 8, when 400 IU of eCG and 150 mu g of PGF were administered. The control group (G-EB9; n = 15) received 1 mg of EB on Day 9, while Group EB8 (G-EB8; n = 15) received the same dose a day earlier. Ovarian ultrasonographic evaluations were performed every 8 h after device removal until ovulation. The timing of EB administration (Day 8 compared with Day 9) did affect the interval between P4 device removal to ovulation (59.4 +/- 2.0 h compared with 69.3 +/- 1.7 h) and maximum diameter of dominant (1.54 +/- 0.06 a cm compared with 1.71 +/- 0.05 b cm, P = 0.03) and ovulatory (1.46 +/- 0.05 a cm compared with 1.58 +/- 0.04 b cm, P < 0.01) follicles. In Experiment 2,504 suckling cows received the same treatment described in Experiment 1, but insemination was performed as follows: Group EB8-AI48h (G-EB8-AI48h; n = 119) and Group EB8-AI54h (G-EB8-AI54h; n = 134) received 1 mg of EB on Day 8 and FrAI was performed, respectively, 48 or 54 h after P4 device removal. Group EB9-AI48h (G-EB9-AI48h; n = 126) and Group EB9-AI54h (G-EB9-AI54h n = 125) received the same treatments and underwent the same FTAI protocols as G-EB8-AI48h and G-EB8-AI54h, respectively; however, EB was administered on Day 9. Conception rates were greater (P < 0.05) in G-EB9-AI54h 163.2% (79/125) a], G-EB9-AI48h [58.7% (74/126) a] and G-EB8-AI48h [58.8% (70/119) a] than in G-EB8-AI54h [34.3% (46/134) b]. We concluded that when EB administration occurred at device withdrawal (D8), the interval to ovulation shortened and dominant and ovulatory follicle diameters decreased. Furthermore, when EB treatment was performed 24 h after device removal, FTAI conducted at either 48 or 54 h resulted in similar conception rates. However, EB treatment on the same day as device withdrawal resulted in a lesser conception rate when FTAI was conducted 54 h after device removal. (C) 2007 Elsevier B.V. All rights reserved.
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
In Experiment 1, effects of an intravaginal progesterone insert (CIDR) for synchronization of estrus in non-suckled cycling primiparous Bos indicus beef cows were evaluated. Cows received either no treatment (Control), prostaglandin F(2 alpha) (PGF), or CIDR (6 d)+prostaglandin F(2 alpha) (CIDR+PGF). There were greater (P<0.05) percentages of cows inseminated and pregnant in 4 d of breeding season in CIDR+PGF (81.6%; 48.7%) than in PGF (53.8%; 32.5%) and Control cows (14.6%; 8.5%). In Experiment 2, efficacy of a treatment with CIDR (6 d)+prostaglandin F(2 alpha)+48 h temporary weaning (CIDR+PGF+TW) associated or not with equine chorionic gonadotropin (eCG) for synchronization of estrus in suckled primiparous B. indicus beef cows was evaluated. Cows were assigned to receive either no treatment (Control), CIDR+PGF+TW, CIDR+PGF+TW+200 IU of eCG, or CIDR+PGF+IW+400 IU of eCG. There were greater (P<0.05) percentages of insemination and pregnancy in 4 d of breeding season in treatment groups (47.0%; 27.5%) than in Control cows(4.5%; 3.0%) and in cows treated with eCG (50.9%; 29.4%) than in cows treated only with CIDR+PGF+TW (39.4%: 23.7%). No effects of eCG dosage were detected. The percentage of cows inseminated and pregnant in a 30 d breeding season were greater (P<0.05) in cows assigned to synchronization treatments (53.3%; 37.2%) than in Control cows (35.3%; 21.4%). In the beginning of the BS, non-suckled primiparous cows treated with CIDR+PGF with estrous cycles having been initiated following calving had greater estrous detection and pregnancy rates than PGF and Control cows, and suckled primiparous cows had improved estrous detection and pregnancy rates when eCG was associated with CIDR+PGF+TW. (C) 2009 Elsevier B.V. All rights reserved.
Resumo:
Five experiments were conducted on commercial farms in Brazil designed to develop the basis for an estrus synchronization protocol using melengestrol acetate (MGA) in Bos indicus cattle. These studies resulted in the development of the following protocol: 0.5 mg.d(-1) of MGA between d -14 and -1; 2.0 mg i.m. injection of estradiol cypionate on d -9; 48 h temporary weaning between d 0 and 2; and natural service beginning on d 0. The basis of this protocol was to induce estrous cyclicity before postpartum loss of body condition, prevent premature luteolysis, eliminate the need for labor required to detect estrus, and consequently increase the likelihood of pregnancy early during the postpartum period. This treatment effectively induced estrous cyclicity among anestrous cows, synchronized estrus activity, and prevented premature luteolysis with no negative effect on pregnancy.