284 research outputs found

    Exclusive vector meson electroproduction @ CLAS

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    We present the results of exclusive electroproduction of vector mesons on the proton at CLAS. We discuss the interpretation of these cross sections in terms of t-channel Reggeon exchanges and in terms of Generalized Parton Distributions (GPDs) formalism.Comment: The 4th Workshop on Exclusive Reactions at High Momentum Transfe

    Understanding The Experiences Of A Group Of Yemeni Students In An Esl Science Class

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    American classrooms are experiencing an influx of diverse language speaking students while for science educators the study of EBL students’ learning in science classrooms is a relatively new field (Lee & Buxton, 2010). At the same time there is a growing emphasis on the importance of science practices (NGSS). This poses significant challenges for science educators who are enacting science curriculum that supports all students’ learning. Supporting EBL students’ academic achievement is significant because literacy is important for students’ access to economic and social benefits that come with science literacy (Atwater, 1996). The purpose of this study was to examine the socio-linguistic challenges that a specific group of EBL students (Yemeni) faced and the extent to which such challenges affected their academic performance in science. These challenges are related to linguistic and cultural interactions, which can lead to conflicts between student and school, thereby interfering with the effectiveness of their education. This study also examined these students’ and their science teacher’s perspectives on strategies that can be used to facilitate their language acquisition during science class and help them become active participants in the school and classroom communities. The study used a qualitative interpretive research methodology and involved four Arab-American EBL students (two males and two females) from Yemen, who had been in the US for different periods of time. The amount of time these students had been in the US was important to examine differences in their acculturation and challenges they faced. Similarly, the use of female and male student participants was important to understand the impact of gender in the lived experiences of these students. The results of the study indicated that all the participants struggled with linguistic, social, and cultural aspects of their life in an American high school. These in turn led to a sense of being different, which resulted in isolation from their non EBL peers. The female participants experienced additional struggles due to their unique dress code that set them apart from the other female students (including those from less strict Arabic cultures), and strict cultural and religious norms that forbade them from interacting with males or with females from cultures other than their own. All these issues influenced each other in different ways, resulting in limited opportunities to interact with others and develop language and cultural competency skills. The results also revealed that even though the school had a large percentage of EBL students from Middle Eastern countries, and the teacher was aware of his EBL students’ struggles and used effective science teaching methods, neither the school nor the teacher had put in place approaches that helped decrease cultural stereotypes among the various student groups and facilitate integration of their EBL students into the school community. As a result, it was difficult for the student participants to academically succeed when language and social and cultural barriers prevented them from feeling like they belonged. This lack of belonging caused the participants to develop a negative attitude towards the American culture, which helped shape their perception of their cultural identity as Arabs

    Exclusive electroproduction of the rho+ meson on the proton @ CLAS

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    We present preliminary results of the exclusive electroproduction of rho+ on the proton at CLAS. We discuss the interpretation of the cross sections in terms of t-channel Reggeon exchanges and in terms of Generalized Parton Distributions (GPDs) formalism.Comment: 12th International Conference on Meson-Nucleon Physics and the Structure of the Nucleon (MENU2010

    Matrix Jacobi Biorthogonal Polynomials via Riemann-Hilbert problem

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    We consider matrix orthogonal polynomials related to Jacobi type matrices of weights that can be defined in terms of a given matrix Pearson equation. Stating a Riemann-Hilbert problem we can derive first and second order differential relations that these matrix orthogonal polynomials and the second kind functions associated to them verify. For the corresponding matrix recurrence coefficients, non-Abelian extensions of a family of discrete Painlev\'e d-PIV equations are obtained for the three term recurrence relation coefficients

    ETNOMATEMATIKA DALAM TRANSAKSI JUAL BELI YANG DILAKUKAN PEDAGANG DI PASAR TRADISIONAL KABUPATEN KAIMANA

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    This study aims to describe ethnomatematics of buying and selling transactions conducted by traders in the traditional market of Kaimana district. It is descriptive researches method with a qualitative approach that emphasizes process analysis. The research subject was one person. The research instrument was in the form of guidelines for observation, interviews, and field notes, which were used to find out how the subjects performed mental calculations. The techniques of analysis data are data reduction, data presentation, and conclusion. Based on the results of the study, it can be concluded that there ethnomatematics activity are show by counting activities in buying and selling transactions. For example, calculate the amount of goods purchased by the buyer, determine the amount of change from the buyer, and calculate the profit of the selling price of each item purchase

    161: Factors predicting mitral restenosis after successful percutaneous mitral commissurotomy

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    IntroductionPercutaneous mitral commissurotomy (PMC) is the alternative treatment of choice for mitral stenosis (MS). Its immediate and medium term results are comparable to those of surgical commissurotomy, however in the long term there is a risk of restenosis. The purpose of this study is to determine the factors predicting restenosis after PMC.Methods322 patients (66% women), average age: 35 ±13 years (9-75 years) having a tight MS and treated by PMC with Inoué balloon. The anatomic aspect of the mitral apparatus before PMC has been studied according to the criteria of the Wilkins score with a concomitant study of the state of mitral commissures. The primary success of PMC is defined as follows: mitral area (MA) post-PMC >1,5cm2 and gain in MA >25% and mitral regurgitation (MR) ≤ grade 2. Mitral restenosis is defined as a MA <1,5cm2 and/or loss >50% of initial gain in MA.ResultsThe rate of primary success of PMC was 86% and mean MA post PMC was 1,82±0,33cm2 compared to MA pre-PMC of 1±0,18cm2 (p <0.0001). Opening of two commissures has been observed in 74% of patients. After an average period of 62±32 months, only 12% of patients had a dyspnea stage IIIIV of NYHA, MA was 1,64±0.3cm2 (p<0.001) and mitral restenosis happened in 47 patients (20%) after a period of 60,48±27 months (22–124 months). The independent predictors of mitral restenosis after a successful PMC were: previous surgical commisurotomy, Wilkins score >8, MA after PMC <1,8cm2 and absence of bicommissural opening post PMC.ConclusionA favorable anatomy of mitral apparatus and the optimisation of immediate result of PMC are the guaranty for the maintain of good result in the long term

    Automatic Noise Reduction in Ultrasonic Computed Tomography Image for Adult Bone Fracture Detection

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    Noise reduction in medical image analysis is still an interesting hot topic, especially in the field of ultrasonic images. Actually, a big concern has been given to automatically reducing noise in human-bone ultrasonic computed tomography (USCT) images. In this chapter, a new hardware prototype, called USCT, is used but images given by this device are noisy and difficult to interpret. Our approach aims to reinforce the peak signal-to-noise ratio (PSNR) in these images to perform an automatic segmentation for bone structures and pathology detection. First, we propose to improve USCT image quality by implementing the discrete wavelet transform algorithm. Second, we focus on a hybrid algorithm combining the k-means with the Otsu method, hence improving the PSNR. Our assessment of the performance shows that the algorithmic approach is comparable with recent methods. It outperforms most of them with its ability to enhance the PSNR to detect edges and pathologies in the USCT images. Our proposed algorithm can be generalized to any medical image to carry out automatic image diagnosis due to noise reduction, and then we have to overcome classical medical image analysis by achieving a short-time process

    Riemann-Hilbert problem for the matrix Laguerre biorthogonal polynomials: the matrix discrete Painleve IV

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    In this paper, the Riemann-Hilbert problem, with a jump supported on an appropriate curve on the complex plane with a finite endpoint at the origin, is used for the study of the corresponding matrix biorthogonal polynomials associated with Laguerre type matrices of weights-which are constructed in terms of a given matrix Pearson equation. First and second order differential systems for the fundamental matrix, solution of the mentioned Riemann-Hilbert problem, are derived. An explicit and general example is presented to illustrate the theoretical results of the work. The non-Abelian extensions of a family of discrete Painleve IV equations are discussed

    The impact of privacy protection filters on gender recognition

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    Deep learning-based algorithms have become increasingly efficient in recognition and detection tasks, especially when they are trained on large-scale datasets. Such recent success has led to a speculation that deep learning methods are comparable to or even outperform human visual system in its ability to detect and recognize objects and their features. In this paper, we focus on the specific task of gender recognition in images when they have been processed by privacy protection filters (e.g., blurring, masking, and pixelization) applied at different strengths. Assuming a privacy protection scenario, we compare the performance of state of the art deep learning algorithms with a subjective evaluation obtained via crowdsourcing to understand how privacy protection filters affect both machine and human vision

    Differential cross section and recoil polarization measurements for the gamma p to K+ Lambda reaction using CLAS at Jefferson Lab

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    We present measurements of the differential cross section and Lambda recoil polarization for the gamma p to K+ Lambda reaction made using the CLAS detector at Jefferson Lab. These measurements cover the center-of-mass energy range from 1.62 to 2.84 GeV and a wide range of center-of-mass K+ production angles. Independent analyses were performed using the K+ p pi- and K+ p (missing pi -) final-state topologies; results from these analyses were found to exhibit good agreement. These differential cross section measurements show excellent agreement with previous CLAS and LEPS results and offer increased precision and a 300 MeV increase in energy coverage. The recoil polarization data agree well with previous results and offer a large increase in precision and a 500 MeV extension in energy range. The increased center-of-mass energy range that these data represent will allow for independent study of non-resonant K+ Lambda photoproduction mechanisms at all production angles.Comment: 22 pages, 16 figure
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