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1.
Sensors (Basel) ; 21(6)2021 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-33808986

RESUMO

Numeral recognition is considered an essential preliminary step for optical character recognition, document understanding, and others. Although several handwritten numeral recognition algorithms have been proposed so far, achieving adequate recognition accuracy and execution time remain challenging to date. In particular, recognition accuracy depends on the features extraction mechanism. As such, a fast and robust numeral recognition method is essential, which meets the desired accuracy by extracting the features efficiently while maintaining fast implementation time. Furthermore, to date most of the existing studies are focused on evaluating their methods based on clean environments, thus limiting understanding of their potential application in more realistic noise environments. Therefore, finding a feasible and accurate handwritten numeral recognition method that is accurate in the more practical noisy environment is crucial. To this end, this paper proposes a new scheme for handwritten numeral recognition using Hybrid orthogonal polynomials. Gradient and smoothed features are extracted using the hybrid orthogonal polynomial. To reduce the complexity of feature extraction, the embedded image kernel technique has been adopted. In addition, support vector machine is used to classify the extracted features for the different numerals. The proposed scheme is evaluated under three different numeral recognition datasets: Roman, Arabic, and Devanagari. We compare the accuracy of the proposed numeral recognition method with the accuracy achieved by the state-of-the-art recognition methods. In addition, we compare the proposed method with the most updated method of a convolutional neural network. The results show that the proposed method achieves almost the highest recognition accuracy in comparison with the existing recognition methods in all the scenarios considered. Importantly, the results demonstrate that the proposed method is robust against the noise distortion and outperforms the convolutional neural network considerably, which signifies the feasibility and the effectiveness of the proposed approach in comparison to the state-of-the-art recognition methods under both clean noise and more realistic noise environments.

2.
Tissue Barriers ; 3(4): e1068908, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26716072

RESUMO

Epithelial sheets, a synapomorphy of all metazoans but porifers, are present as 2 layers in cnidarians, ectoderm and endoderm, joined at their basal side by an extra-cellular matrix named mesoglea. In the Hydra polyp, epithelial cells of the body column are unipotent stem cells that continuously self-renew and concomitantly express their epitheliomuscular features. These multifunctional contractile cells maintain homeostasis by providing a protective physical barrier, by digesting nutrients, by selecting a stable microbiota, and by rapidly closing wounds. In addition, epithelial cells are highly plastic, supporting the adaptation of Hydra to physiological and environmental changes, such as long starvation periods where survival relies on a highly dynamic autophagy flux. Epithelial cells also play key roles in developmental processes as evidenced by the organizer activity they develop to promote budding and regeneration. We propose here an integrative view of the homeostatic and developmental aspects of epithelial plasticity in Hydra.

3.
ScientificWorldJournal ; 2014: 672832, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25386613

RESUMO

Voting is an important operation in multichannel computation paradigm and realization of ultrareliable and real-time control systems that arbitrates among the results of N redundant variants. These systems include N-modular redundant (NMR) hardware systems and diversely designed software systems based on N-version programming (NVP). Depending on the characteristics of the application and the type of selected voter, the voting algorithms can be implemented for either hardware or software systems. In this paper, a novel voting algorithm is introduced for real-time fault-tolerant control systems, appropriate for applications in which N is large. Then, its behavior has been software implemented in different scenarios of error-injection on the system inputs. The results of analyzed evaluations through plots and statistical computations have demonstrated that this novel algorithm does not have the limitations of some popular voting algorithms such as median and weighted; moreover, it is able to significantly increase the reliability and availability of the system in the best case to 2489.7% and 626.74%, respectively, and in the worst case to 3.84% and 1.55%, respectively.


Assuntos
Algoritmos , Software , Computadores , Humanos , Design de Software
4.
ScientificWorldJournal ; 2014: 432952, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25114965

RESUMO

The stability of clusters is a serious issue in mobile ad hoc networks. Low stability of clusters may lead to rapid failure of clusters, high energy consumption for reclustering, and decrease in the overall network stability in mobile ad hoc network. In order to improve the stability of clusters, weight-based clustering algorithms are utilized. However, these algorithms only use limited features of the nodes. Thus, they decrease the weight accuracy in determining node's competency and lead to incorrect selection of cluster heads. A new weight-based algorithm presented in this paper not only determines node's weight using its own features, but also considers the direct effect of feature of adjacent nodes. It determines the weight of virtual links between nodes and the effect of the weights on determining node's final weight. By using this strategy, the highest weight is assigned to the best choices for being the cluster heads and the accuracy of nodes selection increases. The performance of new algorithm is analyzed by using computer simulation. The results show that produced clusters have longer lifetime and higher stability. Mathematical simulation shows that this algorithm has high availability in case of failure.


Assuntos
Algoritmos , Análise por Conglomerados , Redes Neurais de Computação , Modelos Teóricos
5.
Histopathology ; 48(4): 424-30, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16487364

RESUMO

AIMS: Granular cell tumours (GCTs) in the gastrointestinal (GI) tract are rare, with few series reported in the literature. Nestin is a recently identified intermediate filament protein that is expressed in neuroectodermal stem cells and skeletal muscle progenitor cells and has been shown to be expressed in gastrointestinal stromal tumours (GISTs) and GI schwannomas. Herein, we describe the clinicopathological and immunohistochemical features of 11 GI GCTs, introducing nestin as an additional marker that identifies these tumours. METHODS AND RESULTS: The archives of the departments of pathology at London Health Sciences Centre (London, Ontario) and St Michael's Hospital (Toronto, Ontario) were searched for GCTs occurring in the GI tract, yielding 11 cases. Histological features were assessed and immunohistochemistry was performed with S100 protein, nestin, glial fibrillary acidic protein (GFAP), CD34, desmin, CD117, and inhibin-alpha. Charts were reviewed for clinical information. Ages at diagnosis ranged from 31 to 73 years; there were six males and four females. All GCTs were solitary, six in the oesophagus, three in the caecum, one in the rectum and one perianal. Most lesions were discovered incidentally. The size of the GCTs ranged from 4 mm to 30 mm. All were submucosal, typically firm, with a white-yellow appearance. Histologically, the GCTs showed moderate cellularity, predominantly solid growth with areas of nesting. While lesional cells were mainly plump and polygonal, areas of spindling were present in several tumours, more frequently in the colorectum. Margins were circumscribed. Nuclei were round to oval, with even chromatin and small nucleoli. Mitoses were rare to absent and necrosis was absent in all cases. Staining with periodic acid-Schiff, with diastase predigestion, showed globular and diffuse positivity within the cytoplasm. Moderate to strong expression of S100 protein and nestin was observed in 11 of 11 and seven of seven tumours, respectively. GFAP, CD34, desmin, CD117 and inhibin-alpha were negative. While patients were variably managed with resection or observation, all remain clinically well, without disease progression. CONCLUSIONS: Although rare, GI GCTs have characteristic clinicopathological features. Nestin may be a useful immunohistochemical marker for identifying these tumours; the presence of this persistent stem cell cytoskeletal filament within GI GCTs suggests that these lesions may arise from a multipotential stem cell in the GI tract.


Assuntos
Neoplasias Gastrointestinais/patologia , Tumor de Células Granulares/patologia , Proteínas de Filamentos Intermediários/biossíntese , Proteínas do Tecido Nervoso/biossíntese , Adulto , Idoso , Feminino , Neoplasias Gastrointestinais/metabolismo , Tumor de Células Granulares/metabolismo , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Nestina , Proteínas S100/análise
7.
Am J Pathol ; 155(6): 2057-66, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10595935

RESUMO

Alteration of psoriasin (S100A7) expression has previously been identified in association with the transition from preinvasive to invasive breast cancer. In this study we have examined persistence of psoriasin mRNA and protein expression in relation to prognostic factors in a cohort of 57 invasive breast tumors, comprising 34 invasive ductal carcinomas and 23 other invasive tumor types (lobular, mucinous, medullary, tubular). We first developed an IgY polyclonal chicken antibody and confirmed specificity for psoriasin by Western blot in transfected cells and tumors. The protein was localized by immunohistochemistry predominantly to epithelial cells, with both nuclear and cytoplasmic staining, as well as occasional stromal cells in psoriatic skin and breast tumors; however, in situ hybridization showed that psoriasin mRNA expression was restricted to epithelial cells. In breast tumors, higher levels of psoriasin measured by reverse transcriptase-polymerase chain reaction and Western blot (93% concordance) were significantly associated with estrogen and progesterone receptor-negative status (P < 0.0001, P = 0.0003), and with nodal metastasis in invasive ductal tumors (P = 0. 035), but not with tumor type or grade. Psoriasin expression also correlated with inflammatory infiltrates (all tumors excluding medullary, P = 0.0022). These results suggest that psoriasin may be a marker of aggressive behavior in invasive tumors and are consistent with a function as a chemotactic factor.


Assuntos
Neoplasias da Mama/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Western Blotting , Neoplasias da Mama/patologia , Humanos , Imuno-Histoquímica , Hibridização In Situ , Invasividade Neoplásica , Metástase Neoplásica , Prognóstico , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteína A7 Ligante de Cálcio S100 , Proteínas S100 , Células Tumorais Cultivadas
8.
Ear Nose Throat J ; 70(8): 494-6, 1991 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1935713

RESUMO

Before the advent of safe and readily-available intubation anesthesia, most endoscopic procedures were carried out under topical or local anesthesia. Reawakening interest in cost effectiveness in medical practice and improved safety suggests that these techniques should be reexamined. The authors' experience in nearly 2,000 topical anesthetics for peroral endoscopy is reviewed. A preferred technique is presented which has proven effective and has resulted in an overall complication rate of less than 1%.


Assuntos
Anestesia Local/métodos , Anestésicos , Broncoscopia/métodos , Esofagoscopia/métodos , Laringoscopia/métodos , Tetracaína , Administração Tópica , Anestesia Local/economia , Anestesia Local/instrumentação , Broncoscópios , Análise Custo-Benefício , Esofagoscópios , Humanos , Laringoscópios
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