66 research outputs found

    A High permormance hardware architecture for an sad reuse based hierarchical motion estimation algorithm for H.264 video coding

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    In this paper, we present a high performance and low cost hardware architecture for real-time implementation of an SAD reuse based hierarchical motion estimation algorithm for H.264 / MPEG4 Part 10 video coding. This hardware is designed to be used as part of a complete H.264 video coding system for portable applications. The proposed architecture is implemented in Verilog HDL. The Verilog RTL code is verified to work at 68 MHz in a Xilinx Virtex II FPGA. The FPGA implementation can process 27 VGA frames (640x480) or 82 CIF frames (352x288) per second

    Structure and Giant Inverse Magnetocaloric Effect of Epitaxial Ni-Co-Mn-Al Films

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    The structural, magnetic, and magnetocaloric properties of epitaxial Ni-Co-Mn-Al thin films with different compositions have been studied. The films were deposited on MgO(001) substrates by co-sputtering on heated substrates. All films show a martensitic transformation, where the transformation temperatures are strongly dependent on the composition. The structure of the martensite phase is shown to be 14M. The metamagnetic martensitic transformation occurs from strongly ferromagnetic austenite to weakly magnetic martensite. The structural properties of the films were investigated by atomic force microscopy and temperature dependent X-ray diffraction. Magnetic and magnetocaloric properties were analyzed using temperature dependent and isothermal magnetization measurements. We find that Ni41_{41}Co10.4_{10.4}Mn34.8_{34.8}Al13.8_{13.8} films show giant inverse magnetocaloric effects with magnetic entropy change of 17.5\,J\,kg1^{-1}K1^{-1} for μ0ΔH=5T\mu_0 \Delta H=5\,\text{T}.Comment: 8 pages, 8 figure

    Wpływ testosteronowej terapii zastępczej na stężenia witaminy D i FGF-23 w hipogonadyzmie wrodzonym

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    Introduction: Patients with hypogonadism are at increased risk of cardiac and metabolic diseases and osteoporosis. Vitamin D and Fibroblast growth factor-23 (FGF-23) play role in the regulation of bone mineral metabolism and endothelial functions. Low vitamin D levels are reported in hypogonadism, while there is no data about the effect of testosterone replacement therapy (TRT). We investigated the effect of TRT on vitamin D and FGF-23 levels along with endothelial functions and insulin resistance in hypogonadal patients. Material and methods: Patients with congenital hypogonadotrophic hypogonadism (CHH) (n=32, age 20.6 ±1.58 years) were enrolled. TRT was implemented in transdermal form. The demographic parameters, FGF-23, 25(OH)D3, Asymmetric dimethylarginine (ADMA) and homeostatic model assessment of insulin resistance (HOMA-IR) levels were measured both before and after TRT. Results: After a follow-up period of 3.63±1.33 months, ADMA and FGF-23 levels were significantly increased (p=0.03 and p=0.005 respectively), while the 25(OH)D3 and HOMA-IR index were not significantly changed. The body mass index and waist circumference levels of the patients were also increased (p<0.001 and p=0.02) along with a significant decrease in the HDL cholesterol levels (p=0.006). Conclusions: The results show that a short term TRT increases plasma FGF-23 and ADMA levels, in young, treatment naive patients with CHH. Whether this is an early implication of TRT related adverse effects in this very young and treatment naïve population of CHH is not clear. Future prospective studies are required to find out the long-term effects of TRT on cardio-metabolic morbidity and mortality in this specific population.  Wstęp: U chorych z hipogonadyzmem występuje zwiększone ryzyko chorób sercowych I metabolicznych oraz osteoporozy. Witamina D i czynnik wzrostu fibroblastów-23 (FGF-23) uczestniczą w regulacji metabolizmu kostnego i czynności śródbłonka. Istnieją doniesienia na temat niskiego stężenia witaminy D w hipogonadyzmie, natomiast brakuje danych dotyczących wpływu testosteronowej terapii zastępczej (TRT) na to stężenie. Autorzy zbadali wpływ TRT na stężenia witaminy D i FGF-23 oraz na czynność śródbłonka i poziom insulinooporności u chorych z hipogonadyzmem. Materiał i metody: Do badania włączono chorych z wrodzonym hipogonadyzmem hipogonadotropowym (CHH) (n = 32, wiek 20,6 ± 1,58 roku). Chorzy otrzymywali TRT w postaci przezskórnej. Przez rozpoczęciem leczenia i po jego zakończeniu u chorych zebrano dane demograficzne, zmierzono stężenia FGF-23, 25(OH)D3 i asymetryczej dimetyloargininy (ADMA) oraz określono wskaźnik insulinooporności HOMA-IR. Wyniki: Po okresie obserwacji trwającym 3,63 ± 1,33 miesiąca stwierdzono istotne zwiększenie stężeń ADMA i FGF-23 (odpowiednio p = 0,03 i p = 0,005), natomiast stężenie 25(OH)D3 i wskaźnik HOMA-IR nie zmieniły się istotnie. Ponadto zaobserwowano u chorych zwiększenie wskaźnika masy ciała i obwodu pasa (p < 0,001 I p = 0,02) oraz istotne zmniejszenie stężenia cholesterol frakcji HDL (p = 0,006). Wnioski: Wyniki badania pokazują, że krótkotrwałe stosowanie TRT u młodych chorych z CHH, uprzednio nieleczonych, powoduje zwiększenie osoczowego stężenia FGF-23 i ADMA, lecz nie wpływa na stężenie witaminy D. Nie jest jasne, czy jest to wczesny efekt działań niepożądanych TRT w tej grupie bardzo młodych pacjentów z CHH. Konieczne są dalsze prospektywne badania w celu ustalenia długookresowego wpływu TRT na chorobowość i śmiertelność w związku z chorobami sercowymi i metabolicznymi w tej szczególnej populacji

    Evaluation of atrial electromechanical conduction delay in case of hemodynamically insignificant rheumatic heart disease: A tissue Doppler study

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    Background: Atrial electromechanical delay (AEMD) that reflects delayed conduction may show us the clinical reflection of pathological changes in the atria. The main objective of the present study is to investigate AEMD in patients who had previous rheumatic carditis but without hemodynamically significant valvular disease. Methods: A total of 40 patients, previously diagnosed as rheumatic carditis but without significant valvular stenosis/regurgitation and atrial enlargement; and 39 age- and-sex matched controls were enrolled for the present study. Parameters of AEMD (lateral mitral annulus electromechanical delay, septal mitral annulus electromechanical delay and lateral tricuspid annulus electromechanical delay) were measured with tissue Doppler echocardiography and left intra-atrial and inter-atrial conduction times were calculated accordingly. A 24h ambulatory Holter monitoring was used in both groups to detect atrial fibrillation episodes and quantify atrial extrasystoles. Results: Parameters of AEMD, including left intra-atrial and inter-atrial conduction times of subjects in the study group were longer compared to the control group (23.7 ± 7.0 vs. 18.3 ± 6.2). Conclusions: Increased AEMD is observed in patients with previous rheumatic carditis and no significant valvular stenosis/regurgitation and atrial enlargement, which may partly explain the increased incidence of atrial fibrillation observed in these patients

    Nonlinear factor analysis

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    Factor analysis and more general structural equation modeling have been popular statistical tools in social and behavioral sciences, and are useful statistical methods in a wide range of applications. Traditional models in these types of analyses are linear in underlying factors or latent variables. The linear model assumes that the observed variables are linear functions of the underlying factors or latent variables. This assumption may not be valid or realistic in many applications. In behavioral sciences, it is often the case that the linear model fits the data well but with a larger number of factors than expected. In such cases, the subject matter theory usually fails to explain the nature of the unexpected additional factors. Another problem pointed out in application is that the linear model with the maximum allowable number of factors sometimes fails to fit the data. These problems could be due to the existence of nonlinear relationships between observed variables and underlying factors. Models nonlinear in factors may fit the data well and may produce more interpretable results based on the subject matter theory. Nonlinear models can also provide a large class of useful exploratory data analysis tools;This dissertation consists of two papers. In the first paper, we discuss the additive nonlinear factor analysis model which is nonlinear in underlying factors but is linear in parameters. Based on a certain conditional distribution, an estimation procedure for model parameters and a test procedure for checking the model fit are introduced. Asymptotic properties of the estimator and the test procedure are derived using the small-[sigma] asymptotics. A simulation study is also presented. The second paper deals with the general nonlinear factor analysis model. The identification problem for such a model is discussed. Two model fitting procedures are introduced and described. The usefulness and comparison of the procedures are studied through a Monte Carlo experiment.</p

    CFD Analyses of a Notebook Computer Thermal Management System and a Proposed Passive Cooling Alternative

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    A notebook computer thermal management system is analyzed using a commercial computational fluid dynamics software package (ANSYS Fluent). The active and passive paths that are used for heat dissipation are examined for different steady state operating conditions. For each case, average and hot-spot temperatures of the components are compared with the maximum allowable operating temperatures. It is observed that when low heat dissipation components are put on the same passive path, the increased heat load of the path may cause unexpected hot spot temperatures. A hard disk drive is especially susceptible to overheating and the keyboard surface may reach ergonomically undesirable temperatures. Based on the analysis results and observations, a new component arrangement considering passive paths and using the back side of the liquid crystal display screen is proposed and a simple correlation based thermal analysis of the proposed system is presented. It is demonstrated for the considered 16.1 in notebook and for a standard A4 paper sized notebook that placing the computer processing unit, the motherboard, and the memory on the lid creates enough surface area for passive cooling

    CFD ANALYSIS OF A NOTEBOOK COMPUTER THERMAL MANAGEMENT SOLUTION

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    The thermal management system of a commercially available notebook computer is investigated by using a commercial finite volume Computational Fluid Dynamics (CFD) software. After taking the computer apart, all dimensions are measured and all major components are modeled as accurately as possible. Heat dissipation values and some characteristics of the components are obtained from the manufacturer's specifications. Different heat dissipation paths utilized in the design are investigated. Two active fans and aluminum heat dissipation plates as well as the heat pipe system are modeled according to their exact specifications. Under different operating powers, adequacy of the existing thermal management system is observed. Average temperatures of the sides of the casing, the keyboard and the internal components are reported in the form of tables. Thermal resistance networks for five different operating conditions are obtained from the analysis of the CFD simulation results
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