956 research outputs found
Enhancement of Image Segmentation osing Automatic Histogram Thresholding
This study is focused on histogram thresholding methods automatically. In computer vision, Image segmentation is an initial and vital step in a series of processes aimed at overall image understanding. In other words Segmentation refers to the process of partitioning a digital image into the multiple segments (set of pixels as known as super pixels). Two very simple image segmentation techniques that are based on the gray level histogram of an image are Thresholding and Clustering. Thresholding method is widely used for image segmentation approach. It is useful in discriminating foreground from the background. By selecting an adequate threshold value T, or automatically computing threshold value T, the gray level image can be converted in to binary image. Several methods are there to find the threshold automatically for image segmentation. Some of the methods like Otsu, Kapur, Triangle, Iterative and also manually threshold is calculated for different type of images like X-ray computed tomography (CT-Scan), magnetic resonance imaging (MRI), synthetic aperture radar (SAR), Ultrasound image were explained and the results are presented to show the validity of the methods.
DOI: 10.17762/ijritcc2321-8169.16042
A Study on Image Enhancement Techniques using YCbCr Color Space Methods
We propose an image enhancement scheme by using YCBCR color space method. It shows the better feature of the processed input image. The acquired images are classified into three types, word document image, MRI image and scenery image. At first, the acquired inputs are converted to the gray scale to plot with the normalized histogram. Then, using the color space methods, the images are converted into YCBCR characteristics and there components are separated into individual modules(Y, CB, CR components). The processed image separates its in-features of luminance and chrominance components such as Y component, CB component and CR component. In Gray scale image, the Y is said to be the luminance feature also known as single component. In Color image, CB and CR is said to be the chromaticity of blue and red components. Further we find Hue, Saturation and Intensity components are classified from the same samples. Then the proposed technique shows its better performance than the other methods in the enhancement of images corrupted by Gaussian noise. The Experimental result shows that the proposed methods makes good enhancement in visual quality
PISA and high-performing education systems: explaining Singapore's education success
Singapore’s remarkable performance in Programme for International Student Assessment (PISA) has placed it among the world’s high-performing education systems (HPES). In the literature on HPES, its ‘secret formula’ for education success is explained in terms of teacher quality, school leadership, system characteristics and educational reform. This article offers an alternative explanation for the education success of Singapore and, in so doing, questions the basic assertions of the HPES literature and, in particularly, the use of PISA results as the prime indicator of the educational performance of a school system. The explanation is informed by a historical perspective on the development of the Singapore education system and based upon a body of empirical findings on the nature of pedagogical practice in classrooms, both of which are vital for understanding the educational performance of Singapore’s education system. The article concludes by addressing the implications of this analysis for educational policy borrowing
Fostering school-based curriculum development in the context of new educational initiatives in Singapore
Brain Tumour Biomarkers by Deep Learning Architectures
Brain tumour may be detected by the use of different medical imaging modalities such as Computed Tomography (CT) and Magnetic Resonance Imaging (MRI). MRI has been shown to be effective in screening brain tumour than CT. Deep features have been proposed for brain image classification on the basis of two different architectures; Visual Geometric Group (VGG) and Inception Architectures (IA). The need to characterize the brain images as normal or abnormal leads to different deep learning algorithms for the extraction of deep features. The MRI brain image dataset REpository of Molecular BRAin Neoplasia DaTa (REMBRANDT) is studied in this work for the classification. It contains 200 brain images with 100 related to normal and 100 to abnormal. For the analysis, same set of training and testing samples obtained via random split of 50:50 are used by the VGG-16, VGG-19, IA-V1 (GoogleNet) and IA-V3.The classification performance in percentage accuracy, sensitivity and specificity with the above architectures are recorded. Results show that IA-V3 provides best average performance of 95.1% accuracy.  
DNA polymerase α -primase complex from the silk glands of the non-mulberry silkworm Philosamia ricini
The DNA content in the silk glands of the non-mulberry silkworm Philosamia ricini increases continuously during the fourth and fifth instars of larval development indicating high levels of DNA replication in this terminally differentiated tissue. Concomitantly, the DNA polymerase alpha activity also increases in the middle and the posterior silk glands during development, reaching maximal levels in the middle of the fifth larval instar. A comparable level of DNA polymerase delta/epsilon was also observed in this highly replicative tissue. The DNA polymerase alpha-primase complex from the silk glands of P. ricini has been purified to homogeneity by conventional column chromatography as well as by immunoaffinity techniques. The molecular mass of the native enzyme is 560 kDa and the enzyme comprises six non-identical subunits. The identity of the enzyme as DNA polymerase alpha has been established by its sensitivity to inhibitors such as aphidicolin, N-ethylmaleimide, butylphenyl-dGTP, butylanilino-dATP and antibodies to polymerase alpha. The enzyme possesses primase activity capable of initiating DNA synthesis on single-stranded DNA templates. The tight association of polymerase and primase activities at a constant ratio of 6:1 is observed through all the purification steps. The 180 kDa subunit harbours the polymerase activity, while the primase activity is associated with the 45 kDa subunit
Isolation and characterization of DNA polymerase ε from the silk glands of Bombyx mori
The silk gland of Bombyx mori, an endomitotically replicative tissue shows high levels of DNA polymerases alpha, delta, and epsilon activities. The ratio of polymerase alpha to that of delta plus epsilon is maintained at 1.1 to 1.3 in both the posterior and middle silk glands for the entire duration of late larval development. The three activities copurify in the initial stages of fractionation through phosphocellulose and DE52 but polymerase alpha gets resolved from the others on hydroxylapatite column. Separation between polymerase delta and epsilon is achieved by chromatography on QAE-Sephadex. DNA polymerase epsilon is a heterodimer comprising of 215- and 42-kDa subunits. The activity is maximum at pH 6.5 and the Km values for dNTPs vary between 3-9 microM. The enzyme possesses an intrinsically associated exonuclease activity which functions in the mismatch repair during DNA synthesis. Both polymerase and 3'→5' exonuclease activities are associated with the 215-kDa subunit. By itself, DNA polymerase epsilon is processive and the catalytic activity is not enhanced by externally added bPCNA (Bombyx-proliferating cell nuclear antigen, an auxiliary protein for DNA polymerase delta). The enzyme resembles polymerase delta in having the exonuclease activity and in its response to aphidicolin or substrate analogs, but could be distinguished from the latter by its lack of response to the bPCNA and sensitivity to dimethyl sulfoxide. The two enzymes show partial immunological cross-reactivity with each other but no immunological relatedness to polymerase alpha. The absence of the repair enzyme DNA polymerase beta and the presence of substantial levels of polymerase epsilon in the silk glands suggest a possible role for the latter in DNA repair in that tissue
A Critique of Knowledge-Based Economies: A Case Study of Singapore Education Stakeholders
This article critically examines the sense-making processes of key stakeholders of Singapore's education: a historically dominant city-state, highly-qualified teachers, and high-performing students. The article interrogates the Teaching Schools Learning Nation policy initiative deployed toward achieving a knowledge-based economy. The article uses micropolitics in exploring issues that stakeholders face in the midst of globalization. Findings from research at the Centre for Research in Pedagogy and Practice at the National Institute of Education support key arguments. In exploring sense-making processes, the article uncovers paradoxical interpretational responses of stakeholders implementing the Teaching Schools Learning Nation policy, providing a critique of the city-state's knowledge-based economy ambitions
DNA polymerase-delta from the silk glands of Bombyx mori
The silk gland of Bombyx mori is a terminally differentiated tissue in which DNA replication continues without cell or nuclear division during larval development. DNA polymerase-delta activity increases in the posterior and middle silk glands during the development period, reaching maximal levels in the middle of the fifth instar larvae. The enzyme has been purified to homogeneity by a series of column chromatographic and affinity purification steps. It is a multimer comprising of three heterogeneous subunits, M(r) 170,000, 70,000, and 42,000. An auxiliary protein from B. mori silk glands, analogous to the proliferating cell nuclear antigen, enhances the processivity of the enzyme and stimulates catalytic activity by 3-fold. This auxiliary protein has also been purified to homogeneity. It is a dimer comprised of a single type M(r) 40,000 subunit. Polymerase-delta possesses an intrinsic 3'----5' exonuclease activity which participates in proofreading by mismatch repair during DNA synthesis and is devoid of any primase activity. DNA polymerase-delta activity could be further distinguished from polymerase-alpha from the same tissue based on its sensitivity to various inhibitors and polyclonal antibodies to the individual enzymes. Like DNA polymerase-alpha, polymerase-delta is also tightly associated with the nuclear matrix. The polymerase alpha-primase complex could be readily separated from polymerase-delta (exonuclease) in the purification protocol adopted. DNA polymerase-delta from B. mori silk glands resembles the mammalian delta-polymerases. Considering that both DNA polymerase-delta and -alpha are present in nearly equal amounts in this highly replicative tissue and their close association with the nuclear matrix, the involvement of both the enzymes in the chromosomal endoreplication process in B. mori is strongly implicated
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