892 resultados para Shadow and Highlight Invariant Algorithm.


Relevância:

100.00% 100.00%

Publicador:

Resumo:

The objective of this thesis is to investigate, through an empirical study, the different functions of the highways maintenance departments and to suggest methods by means of which road maintenance work could be carried out in a more efficient way by utilising its resources of men, material and plant to the utmost advantage. This is particularly important under the present circumstances of national financial difficulties which have resulted in continuous cuts in public expenditure. In order to achieve this objective, the researcher carried out a survey among several Highways Authorities by means of questionnaire and interview. The information so collected was analysed in order to understand the actual, practical situation within highways manintenance departments, and highlight any existing problems, and try to answer the question of how they could become more efficient. According to the results obtained by the questionnaire and the interview, and the analysis of these results, the researcher concludes that it is the management system where least has been done, and where problems exist and are most complex. The management of highways maintenance departments argue that the reasons for their problems include both financial and organisational difficulties, apart from the political aspect and nature of the activities undertaken. The researcher believes that this ought to necessitate improving the management's analytical tools and techniques in order to achieve the most effective way of performing each activity. To this end the researcher recommends several related procedures to be adopted by the management of the highways maintenance departments. These recommendations, arising from the study, involve the technical, practical and human aspects. These are essential factors of which management should be aware - and certainly should not neglect - in order to achieve its objectives of improved productivity in the highways maintenance departments.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Intermittent photic stimulation (IPS) is a common procedure performed in the electroencephalography (EEG) laboratory in children and adults to detect abnormal epileptogenic sensitivity to flickering light (i.e., photosensitivity). In practice, substantial variability in outcome is anecdotally found due to the many different methods used per laboratory and country. We believe that standardization of procedure, based on scientific and clinical data, should permit reproducible identification and quantification of photosensitivity. We hope that the use of our new algorithm will help in standardizing the IPS procedure, which in turn may more clearly identify and assist monitoring of patients with epilepsy and photosensitivity. Our algorithm goes far beyond that published in 1999 (Epilepsia, 1999a, 40, 75; Neurophysiol Clin, 1999b, 29, 318): it has substantially increased content, detailing technical and logistical aspects of IPS testing and the rationale for many of the steps in the IPS procedure. Furthermore, our latest algorithm incorporates the consensus of repeated scientific meetings of European experts in this field over a period of 6 years with feedback from general neurologists and epileptologists to improve its validity and utility. Accordingly, our European group has provided herein updated algorithms for two different levels of methodology: (1) requirements for defining photosensitivity in patients and in family members of known photosensitive patients and (2) requirements for tailored studies in patients with a clear history of visually induced seizures or complaints, and in those already known to be photosensitive.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Sport and exercise psychologists provide some interventions for clients based on limited direct evidence and partial understanding of the mechanisms that underpin their efficacy. The authors review a recent technique, transcranial magnetic stimulation (TMS), which offers a tested procedure for investigating cortical activity during observation and imagery processes. They provide a detailed description of the TMS protocol and highlight some of the key studies that inform sport and exercise psychology research. Finally, the authors offer some thoughts on the direct application to practice.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We have developed a novel multilocus sequence typing (MLST) scheme and database (http://pubmlst.org/pacnes/) for Propionibacterium acnes based on the analysis of seven core housekeeping genes. The scheme, which was validated against previously described antibody, single locus and random amplification of polymorphic DNA typing methods, displayed excellent resolution and differentiated 123 isolates into 37 sequence types (STs). An overall clonal population structure was detected with six eBURST groups representing the major clades I, II and III, along with two singletons. Two highly successful and global clonal lineages, ST6 (type IA) and ST10 (type IB1), representing 64?% of this current MLST isolate collection were identified. The ST6 clone and closely related single locus variants, which comprise a large clonal complex CC6, dominated isolates from patients with acne, and were also significantly associated with ophthalmic infections. Our data therefore support an association between acne and P. acnes strains from the type IA cluster and highlight the role of a widely disseminated clonal genotype in this condition. Characterization of type I cell surface-associated antigens that are not detected in ST10 or strains of type II and III identified two dermatan-sulphate-binding proteins with putative phase/antigenic variation signatures. We propose that the expression of these proteins by type IA organisms contributes to their role in the pathophysiology of acne and helps explain the recurrent nature of the disease. The MLST scheme and database described in this study should provide a valuable platform for future epidemiological and evolutionary studies of P. acnes.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Special issue editorial: Purpose – The purpose of this paper is to outline the articles presented in the Special Issue on the topic of “Marketing and flexibility”, and to discuss key issues associated with major debates relating to flexibility in order to position the articles within a wider context and highlight some key issues for further research. Design/methodology/approach – Themes in prior research relating to “Marketing and flexibility” are documented and the growth of research interest into strategic flexibility is tabulated. The contributions of each article are briefly discussed. Findings – There has been a steady growth of research interest into flexibility. To provide an example of this growth, the increase in the number of articles published on the topic of strategic flexibility in scholarly journals is highlighted over a 20-year period. Key issues in prior research such as alternative definitions and the different postulated relationships between market orientation and strategic flexibility are revealed, as are issues for future research. Originality/value – Key issues relating to research into flexibility for marketing scholars are revealed.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In human (D. H. Baker, T. S. Meese, & R. J. Summers, 2007b) and in cat (B. Li, M. R. Peterson, J. K. Thompson, T. Duong, & R. D. Freeman, 2005; F. Sengpiel & V. Vorobyov, 2005) there are at least two routes to cross-orientation suppression (XOS): a broadband, non-adaptable, monocular (within-eye) pathway and a more narrowband, adaptable interocular (between the eyes) pathway. We further characterized these two routes psychophysically by measuring the weight of suppression across spatio-temporal frequency for cross-oriented pairs of superimposed flickering Gabor patches. Masking functions were normalized to unmasked detection thresholds and fitted by a two-stage model of contrast gain control (T. S. Meese, M. A. Georgeson, & D. H. Baker, 2006) that was developed to accommodate XOS. The weight of monocular suppression was a power function of the scalar quantity ‘speed’ (temporal-frequency/spatial-frequency). This weight can be expressed as the ratio of non-oriented magno- and parvo-like mechanisms, permitting a fast-acting, early locus, as befits the urgency for action associated with high retinal speeds. In contrast, dichoptic-masking functions superimposed. Overall, this (i) provides further evidence for dissociation between the two forms of XOS in humans, and (ii) indicates that the monocular and interocular varieties of XOS are space/time scale-dependent and scale-invariant, respectively. This suggests an image-processing role for interocular XOS that is tailored to natural image statistics—very different from that of the scale-dependent (speed-dependent) monocular variety.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Link adaptation (LA) plays an important role in adapting an IEEE 802.11 network to wireless link conditions and maximizing its capacity. However, there is a lack of theoretic analysis of IEEE 802.11 LA algorithms. In this article, we propose a Markov chain model for an 802.11 LA algorithm (ONOE algorithm), aiming to identify the problems and finding the space of improvement for LA algorithms. We systematically model the impacts of frame corruption and collision on IEEE 802.11 network performance. The proposed analytic model was verified by computer simulations. With the analytic model, it can be observed that ONOE algorithm performance is highly dependent on the initial bit rate and parameter configurations. The algorithm may perform badly even under light channel congestion, and thus, ONOE algorithm parameters should be configured carefully to ensure a satisfactory system performance. Copyright © 2011 John Wiley & Sons, Ltd.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The open content creation process has proven itself to be a powerful and influential way of developing text-based content, as demonstrated by the success of Wikipedia and related sites. Distributed individuals independently edit, revise, or refine content, thereby creating knowledge artifacts of considerable breadth and quality. Our study explores the mechanisms that control and guide the content creation process and develops an understanding of open content governance. The repertory grid method is employed to systematically capture the experiences of individuals involved in the open content creation process and to determine the relative importance of the diverse control and guiding mechanisms. Our findings illustrate the important control and guiding mechanisms and highlight the multifaceted nature of open content governance. A range of governance mechanisms is discussed with regard to the varied levels of formality, the different loci of authority, and the diverse interaction environments involved. Limitations and opportunities for future research are provided.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

For over 30. years information-processing approaches to leadership and more specifically Implicit Leadership Theories (ILTs) research has contributed a significant body of knowledge on leadership processes in applied settings. A new line of research on Implicit Followership Theories (IFTs) has re-ignited interest in information-processing and socio-cognitive approaches to leadership and followership. In this review, we focus on organizational research on ILTs and IFTs and highlight their practical utility for the exercise of leadership and followership in applied settings. We clarify common misperceptions regarding the implicit nature of ILTs and IFTs, review both direct and indirect measures, synthesize current and ongoing research on ILTs and IFTs in organizational settings, address issues related to different levels of analysis in the context of leadership and follower schemas and, finally, propose future avenues for organizational research. © 2013 Elsevier Inc.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This article draws upon the use of photography to research the lives of children living in Accra, Ghana. Its aim is to consider method in visual research, and to reflect upon those modes of explanation and understanding that any consideration of method must require. It suggests a role for photography as a 'vector', as something capable of connecting our knowledge and understanding of the everyday with the everyday experiences and reality of others. Drawing upon the photographs and spoken testimonies of children who live and work on the street, and of children who live in a large informal settlement, the article advances an intimate connection between photography and knowledge of the everyday reality of children's lives, most evident in the capacity of children's photographs to surprise and highlight the fallibility of our understandings. © 2010 International Visual Sociology Association.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We develop the institutional configuration perspective to understand which national contexts facilitate social entrepreneurship (SE). We confirm joint effects on SE of formal regulatory (government activism), informal cognitive (postmaterialist cultural values), and informal normative (socially supportive cultural norms, or weak-tie social capital) institutions in a multilevel study of 106,484 individuals in 26 nations. We test opposing propositions from the institutional void and institutional support perspectives. Our results underscore the importance of resource support from both formal and informal institutions, and highlight motivational supply side influences on SE. They advocate greater consideration of institutional configurations in institutional theory and comparative entrepreneurship research.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The glucagon-like peptide-1 receptor (GLP-1R) is a class B G protein-coupled receptor that has a critical role in the regulation of glucose homeostasis, principally through the regulation of insulin secretion. The receptor systemis highly complex, able to be activated by both endogenous [GLP-1(1-36)NH2, GLP-1(1-37), GLP-1(7-36)NH2, GLP-1(7-37), oxyntomodulin], and exogenous (exendin-4) peptides in addition to small-molecule allosteric agonists (compound 2 [6,7-dichloro-2-methylsulfonyl-3-tertbutylaminoquinoxaline], BETP [4-(3-benzyloxy)phenyl)-2-ethylsulfinyl-6-(trifluoromethyl)pyrimidine]). Furthermore, the GLP-1R is subject to single-nucleotide polymorphic variance, resulting in amino acid changes in the receptor protein. In this study, we investigated two polymorphic variants previously reported to impact peptidemediated receptor activity (M149) and small-molecule allostery (C333). These residues were mutated to a series of alternate amino acids, and their functionality was monitored across physiologically significant signaling pathways, including cAMP, extracellular signal-regulated kinase 1 and 2 phosphorylation, and intracellular Ca2+ mobilization, in addition to peptide binding and cell-surface expression. We observed that residue 149 is highly sensitive to mutation, with almost all peptide responses significantly attenuated at mutated receptors. However, most reductions in activity were able to be restored by the small-molecule allosteric agonist compound 2. Conversely, mutation of residue 333 had little impact on peptide-mediated receptor activation, but this activity could not be modulated by compound 2 to the same extent as that observed at the wild-type receptor. These results provide insight into the importance of residues 149 and 333 in peptide function and highlight the complexities of allosteric modulation within this receptor system.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The paper has been presented at the International Conference Pioneers of Bulgarian Mathematics, Dedicated to Nikola Obreshkoff and Lubomir Tschakalo ff , Sofia, July, 2006.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In this paper a novel method for an application of digital image processing, Edge Detection is developed. The contemporary Fuzzy logic, a key concept of artificial intelligence helps to implement the fuzzy relative pixel value algorithms and helps to find and highlight all the edges associated with an image by checking the relative pixel values and thus provides an algorithm to abridge the concepts of digital image processing and artificial intelligence. Exhaustive scanning of an image using the windowing technique takes place which is subjected to a set of fuzzy conditions for the comparison of pixel values with adjacent pixels to check the pixel magnitude gradient in the window. After the testing of fuzzy conditions the appropriate values are allocated to the pixels in the window under testing to provide an image highlighted with all the associated edges.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A novel approach of normal ECG recognition based on scale-space signal representation is proposed. The approach utilizes curvature scale-space signal representation used to match visual objects shapes previously and dynamic programming algorithm for matching CSS representations of ECG signals. Extraction and matching processes are fast and experimental results show that the approach is quite robust for preliminary normal ECG recognition.