基于特征图切分的轻量级卷积神经网络

卷积神经网络模型所需的存储容量和计算资源远超出移动和嵌入式设备的承载量,因此文中提出轻量级卷积神经网络架构(SFNet).SFNet架构引入切分模块的概念,通过将网络的输出特征图进行“切分”处理,每个特征图片段分别输送给不同大小的卷积核进行卷积运算,将运算得到的特征图拼接后由大小为1×1的卷积核进行通道融合.实验表明,相比目前通用的轻量级卷积神经网络,在卷积核数目及输入特征图通道数相同时,SFNet的参数和计算量更少,分类正确率更高.相比标准卷积,在网络复杂度大幅降低的情况下,切分模块的分类正确率持平甚至更高.     

Investigation of defect structure of neutron-irradiated crystalline silicon by low-temperature thermal conductivity

The thermal conductivity of initially n-type silicon irradiated at temperatures higher than room temperature with fast neutron doses between 2·10¹⁸ and 2·10¹⁹ n/cm² and following thermal annealing at 375 °C and 800 °C was measured at low temperatures (2–200 K). Additionally, the heat capacity was investigated in the temperature range from 2 K to 50 K. With the help of the analysis of (T) on the basis of the Callaway model, results on the nature of neutron-induced defects and their change by annealing were obtained. The neutron-induced damage can be described by point defects and by extended defects in the kind of dislocations or dislocation loops, respectively. The interaction of point defects with phonons appears as Rayleigh scattering and partially as resonance-like scattering. At the Si sample with highest neutron dose, an anomalous behavior (cooling effect) was observed after annealing at 375 °C. The state of structure is not stable by cooling between room temperature and 78 K and therefore a decrese of (T) with each cooling cycle is obtained. A significant change of specific heat was not observed by neutron irradiation.     

Diabetes mellitus in Egypt: glycaemic control and microvascular and neuropathic complications

We performed a cross-sectional, population-based survey of persons 20 years of age and older living in Cairo and surrounding rural villages. The purpose was to describe glycaemic control and the prevalence of microvascular and neuropathic complications among Egyptians with diagnosed diabetes, previously undiagnosed diabetes, impaired glucose tolerance, and normal glucose tolerance. A total of 6052 households were surveyed. The response rate was 76% for the household survey and 72% for the medical examination. Among people with previously diagnosed diabetes, mean haemoglobin A1c, was 9.0%. Forty-two per cent had retinopathy, 21% albuminuria, and 22% neuropathy. Legal blindness was prevalent (5%) but clinical nephropathy (7%) and foot ulcers (1%) were uncommon in persons with diagnosed diabetes. Among people with diagnosed diabetes, microvascular and neuropathic complications were associated with hyperglycaemia. Retinopathy was also associated with duration of diabetes; albuminuria with hypertension and hypercholesterolaemia; and neuropathy with age, female sex, and hypercholesterolaemia. Albuminuria was as common in people with previously undiagnosed diabetes (22%) as those with diagnosed disease (21%). Mean haemoglobin A1c was lower (7.8%) and retinopathy (16%) and neuropathy (14%) were less prevalent in people with previously undiagnosed disease. Ocular conditions, blindness, and neuropathy were prevalent in the non-diabetic population. The microvascular and neuropathic complications of diabetes are a major clinical and public health problem in Egypt.     

Amé lioration de 1' apport thematique d' une image SPOT XS par les processus spatiaux et une methode de segmentation: application a la ré gion de Lagdo (Nord-Cameroun)

The current orientation of remote sensing applied research favours the use of both multisource and multidate data which are not always available to developing countries. The exploitation of the data available must therefore be optimized. This paper shows that we can improve the thematical supply of a simple picture by using some methods that bring together PCA ( principal component analysis) image restoration and segmentation.     

Effect of Handling,Packing and Transportation on the Moisture of Timber Wood

In order to improve the efficiency of moisture meters calibrations, we studied the effect of ambient humidity, sample handling, packing and transportation on the timber wood (spruce) moisture determination. It was proved by experiments that dry timber samples (\(12 \times 12 \times 2.5\) cm) reach equilibrium within 30–40 days even when moisturizing them at a high relative air humidity (80 %). On the other hand, the major mass loss of moist samples placed at normal laboratory conditions was found to occur during the first few days while the first 5 days are critical. The effects of sample handling, packing and transportation were studied by means of interlaboratory comparison between CMI, CETIAT, INRIM, NIS and KRISS. The obtained results show that samples with moisture content less than 7 % tend to absorb small amount of water, whereas samples with moisture content larger than 15 % tend to desorb small amount of water during the handling and transporting even when using vacuum packing and short handling times.     

Methane conversion using a dielectric barrier discharge reactor at atmospheric pressure for hydrogen production

In the present paper,we carried out a theoretical study of dielectric barrier discharge (DBD) filled with pure methane gas.The homogeneous discharge model used in this work includes a plasma chemistry unit,an electrical circuit,and the Boltzmann equation.The model was applied to the case of a sinusoidal voltage at a period frequency of 50 kHz and under a gas pressure of 600 Torr.We investigated the temporal variation of electrical and kinetic discharge parameters such as plasma and dielectric voltages,the discharge current density,electric field,deposited power density,and the species concentration.We also checked the physical model validity by comparing its results with experimental work.According to the results discussed herein,the dielectric capacitance is the parameter that has the greatest effect on the methane conversion and H2/CH4 ratio.This work enriches the knowledge for the improvement of DBD for CH4 conversion and hydrogen production.