369 research outputs found

    Reconnaissance de feuilles d'arbres par fusion de décisions partielles

    Get PDF
    National audienceDans le cadre du développement d'une application Smartphone destinée à la reconnaissance des espèces d'arbres, une stratégie basée sur des sous-classifieurs a été mise en place pour reconnaître les feuilles à partir des caractéristiques liées à la base, au sommet et au contour. La théorie des fonctions de croyance est appliquée sur la sortie de chaque sous-classifieur afin de raffiner les résultats en diminuant l'effet de l'incertitude qui existe sur les caractéristiques des feuilles. La décision finale sur l'espèce de feuille est prise en transformant la croyance en probabilité pignistique et en accumulant les probabilités issues de chaque sous-classifieur pour chaque espèce. Les résultats démontrent que notre méthode de sous-classification et de décision obtient de bonnes performances

    Effect of temozolomide combined with radiotherapy on survival and MGMT protein expression in recurrent malignant glioma patients

    Get PDF
    Purpose: To investigate the effect of temozolomide (TMZ) combined with radiotherapy (RT) on O-6- methylguanine-DNA methyltransferase (MGMT) protein and survival of recurrent malignant glioma patients. Methods: Ninety-two patients with malignant glioma in our hospital from January 2014 to January 2015 were assigned to study and control groups using the random table method. Subjects in the control group received radiotherapy (total dose in the range of 60 – 75 Gy), while those in the study group were given TMZ orally (75 mg/m2) daily in addition to radiotherapy, as well as TMZ at 150 – 200 mg/m2. After treatment, clinical effectiveness was compared for the two groups. Changes in methylation of MGMT gene were determined in the two groups. The patients were followed up for 3 years, and the degrees of survival and recurrence were recorded. Results: Total effectiveness of clinical treatment was markedly higher in the study group (76.09 %) than in the control group (45.65 %; p < 0.05). One month after radiotherapy, significant decrease in MGMT gene methylation was seen in patients in the study group, relative to control patients (p < 0.05). Patients in the study group had lower median recurrence but higher degree of survival in the 2nd and 3rd years, relative to control patients (p < 0.05). Conclusion: The combination of temozolomide and radiotherapy is more effective than radiotherapy in the treatment of recurrent malignant glioma. The combined treatment significantly inhibits tumor recurrence in patients, and improves their prognosis and standard of life

    Implementation of a radial disk ionization profile in the relxill_nk model

    Get PDF
    Very steep reflection emissivity profiles in the inner part of accretion disks are commonly found in the analysis of X-ray observations of black hole binaries and AGN, but there is some debate about their exact origin. While steep reflection emissivity profiles can be naturally produced by compact coronae close to black holes, the measured radial emissivity parameter can be further increased by the radial disk ionization profile when the theoretical model assumes a disk with constant ionization. In this paper, we implement the possibility of a radial disk ionization profile in the reflection model RELXILL_NK, which is a package designed to calculate reflection spectra of "deformed" Kerr black holes. We analyze a NuSTAR observation of the black hole binary EXO 1846-031, which was previously found to have a very high inner emissivity index. We find that the model with a radial disk ionization profile improves the fit, but the impact on the estimate of the black hole spin parameter and on the constraint of the deformation parameter is modest. However, we show that the analysis of future observations of Athena and eXTP will necessarily require models with a radial disk ionization profile to have accurate constraints of the deformation parameters.Comment: 9 pages, 6 figures. v2: refereed versio

    Effects of process parameters on bondability in thermosonic copper ball bonding

    Get PDF
    Thermosonic copper ball bonding is an absorbing interconnection technology that serves as a viable and cost saving alternative to gold ball bonding. Its excellent mechanical and electrical characteristics make copper ball bonding attractive for high-speed, power devices and fine-pitch applications. However, copper is easily oxidized and harder than gold, which causes some critical process problems in connection with bondability. In this study, a 50 mum copper wire with purity of 99.99% was bonded on aluminum metallization with thickness 3 mum using an ASM angle 60 automatic thermosonic ball/wedge bonder. Experimental studies of copper free air balls (FABs) formation and bonding process were conducted to establish the bonding mechanism and to explain the effects of process parameters on bondability. A micro-slipping model was proposed to account for the effects of the ultrasonic power and bonding force on bondability. It was found that the bondability was determined by a slip area at the bonding interface. The occurrence of bonding only at the periphery of the contact area between FAB and aluminum metallization was attributed to partial slips at the bonding interface. Variation in the ultrasonic power and bonding force that lead to different stick-slip modes, can effect bondability in the ultrasonic bonding process. It is important to set a proper bonding time to achieve interatomic bonding without causing fatigue rupture of microjoints. It was also found that preheating of the chip to a certain temperature can improve bondability

    NEW METHODS TO DETERMINE 3-D ROTATIONAL INERTIA

    Get PDF
    Due to the different stature of the various nationalities and the limitation of the sample or the divergent research methods, the results on human-body inertia parameters of occidentals are not suitable to be applied to oriental adults. In this study, the 3-D principal inertia of each segment and of the entire body of Chinese adults was determined and the mathematical models for calculating their parameters were constructed. The results from this study can aid in the development of the prosthetic limbs for invalids, and analysis of the movements of astronauts, etc. In addition, the regression equations for calculating 3-D principal inertia of human standard postures and for each segment were derived. Their reliability are tested and verified by threestring pendulum method

    Measuring Black Hole Spins through X-ray Reflection Spectroscopy and the Relativistic Precession Model: the case of XTE J1859+226

    Full text link
    The development of techniques to measure accurately black hole spins is crucial to study the physics and astrophysics of these objects. X-ray reflection spectroscopy is currently the most popular method to estimate the spins of accreting black holes; so far it has provided a spin measurement of about 40 stellar-mass black holes in X-ray binaries and 40 supermassive black holes in active galactic nuclei. The relativistic precession model is another method to measure the spins of stellar-mass black holes: it requires the measurement of the frequencies of three simultaneous quasi-periodic oscillations and can potentially provide very precise estimates of the black hole mass and spin. However, the two methods do not seem to provide consistent results when applied to the same sources, which questions the actual reliability and accuracy of these measurements. Recently, the relativistic precession model has been applied to infer the spin of the black hole in XTE J1859+226 (Motta et al. 2022). The authors found a∗=0.149±0.005a_* = 0.149 \pm 0.005 (68% CL) and there are no other spin measurements of this source. We looked for archived RXTE observations of XTE J1859+226 with blurred reflection features and found 23 spectra suitable for measuring the black hole spin. We employed two different models with relxill and relxillD and obtained a higher spin value from all these fits. From the further simultaneous fitting performed on two different subsets of the total set of 23 spectra, we infer the black hole spin parameter a∗=0.986−0.004+0.001a_* = 0.986^{+0.001}_{-0.004} and a∗=0.987±0.003a_* =0.987 \pm 0.003 (90% CL, statistical) with relxill and relxillD for the first set and, a∗a_* = 0.981−0.007+0.0060.981_{-0.007}^{+0.006} and 0.982−0.007+0.0060.982_{-0.007}^{+0.006} (90% CL, statistical) for the second set, respectively. This clearly confirms the discrepancy between the black hole spin measurements inferred from the two techniques.Comment: 14 pages, 9 figure

    Changes in Adipokines following Laparoscopic Roux-en-Y Gastric Bypass Surgery in Chinese Individuals with Type 2 Diabetes Mellitus and BMI of 22–30 kg·m −2

    Get PDF
    Aims. Although altered endocrine changes following bariatric surgery in morbidly obese patients with diabetes have been demonstrated by previous studies, little is known about their effects on low BMI patients of T2DM. We investigated the changes in adipokines and sICAM-1 in Chinese subjects with low BMI and T2DM after LRYGB and explored their relationship with postsurgical insulin sensitivity. Methods. Plasma levels of adiponectin, sICAM-1, fasting glucose, glycated hemoglobin, and fasting insulin and serum levels of visfatin were measured before and at three months after LRYGB in 33 T2DM patients with BMI of 22–30 kg·m−2. Results. Significant reductions in anthropometric measurements and indicators of glucose and lipid metabolism and moderate reductions in insulin resistance and fasting insulin were observed at three months after LRYGB. Postoperative adiponectin level () was increased compared to the preoperative level, whereas visfatin () and sICAM-1 () were lower than that before surgery. Serum adiponectin negatively correlated with HOMA-IR and FIns both preoperatively and at three months after surgery, and visfatin positively correlated with HOMA-IR and FIns both preoperatively and postoperatively. Conclusion. Changes in adipokines were related to an improvement in postsurgical insulin sensitivity, which was predicted by weight loss after LRYGB even in low BMI patients with T2DM
    • …
    corecore