Locally Optimum Detection of Weak Pulse Signals in Non-Gaussian Noise

In this paper, the problem of locally optimum detection of weak pulse signals in narrow-band non-Gaussian noise is discussed. A generalized model is proposed for locally optimum detectors (LOD) and the corresponding physical meaning is explained. On the basis of this generalized model, the LOD structures are derived for detecting both coherent- and incoherent-pulse signals in narrow-band non-Gaussian noise. The asymptotic relative efficiency (ARE) due to Pitman is used to evaluate the performance of these LODs. Finally, numerical calculations are carried out for the AREs of these LODs and some valuable results are obtained.

Brain networks modeling for studying the mechanism underlying the development of Alzheimer’s disease

Alzheimer’s disease is a primary age-related neurodegenerative disorder that can result in impaired cognitive and memory functions.Although connections between changes in brain networks of Alzheimer’s disease patients have been established,the mechanisms that drive these alterations remain incompletely understood.This study,which was conducted in 2018 at Northeastern University in China,included data from 97 participants of the Alzheimer’s Disease Neuroimaging Initiative(ADNI)dataset covering genetics,imaging,and clinical data.All participants were divided into two groups:normal control(n=52;20 males and 32 females;mean age 73.90±4.72 years)and Alzheimer’s disease(n=45,23 males and 22 females;mean age 74.85±5.66).To uncover the wiring mechanisms that shaped changes in the topology of human brain networks of Alzheimer’s disease patients,we proposed a local naive Bayes brain network model based on graph theory.Our results showed that the proposed model provided an excellent fit to observe networks in all properties examined,including clustering coefficient,modularity,characteristic path length,network efficiency,betweenness,and degree distribution compared with empirical methods.This proposed model simulated the wiring changes in human brain networks between controls and Alzheimer’s disease patients.Our results demonstrate its utility in understanding relationships between brain tissue structure and cognitive or behavioral functions.The ADNI was performed in accordance with the Good Clinical Practice guidelines,US 21 CFR Part 50-Protection of Human Subjects,and Part 56-Institutional Review Boards(IRBs)/Research Good Clinical Practice guidelines Institutional Review Boards(IRBs)/Research Ethics Boards(REBs).

Financial Development, Foreign Direct Investment, and the Efficiency of Capital Allocation in China

We study the roles of local financial development and foreign direct investment, and more importantly, their interaction with one another, in local capital allocation, based on Chinese industrial and regional data. Our main finding is that, although local financial development and FDI each individually tended to improve the efficiency of local capital allocation during the sample period, they tended to compete and crowd out each other＇s effect, so that one impaired the individual function of the other. In particular, there exists a threshold value for local financial development, above which an increase in FDI reduces the efficiency of local capital allocation, rather than improve it. On the other hand, there exists a threshold value for FDI, above which further development in the local financial system lowers the efficiency of local capital allocation, rather than increase it. Our estimations suggest that the levels of FDI and local financial development in some relatively more developed Chinese regions have already surpassed such threshold values. We provide some interpretations of our findings and we discuss potential policy implications.

Influence of Some Physical Parameters on the Separation Efficiency of a Gas Centrifuge

To increase the separation efficiency of a gas centrifuge is one of the key objectives for uranium isotope separation. It can provide great benefit with little effort. The separation efficiency is affected by many parameters.Some physical parameters, such as the pressure of UF, at the wall of the centrifuge cylinder. the position of the wastescoop. the tempwrature profile on the wall of the centrituge cylindwer. the direction of the feed into the gas centrifuge are chosen as variables to optimize the separation efficiency of a gas centrifuge. The optimization is based on analytical and experimental results. Local separation efficiency distribution is a good method to describe the separation phenomena in the gas centrifuge.

RB-SLAM:visual SLAM based on rotated BEBLID feature point description

The extraction and description of image features are very important for visual simultaneous localization and mapping(V-SLAM).A rotated boosted efficient binary local image descriptor(BEBLID)SLAM(RB-SLAM)algorithm based on improved oriented fast and rotated brief(ORB)feature description is proposed in this paper,which can solve the problems of low localization accuracy and time efficiency of the current ORB-SLAM3 algorithm.Firstly,it uses the BEBLID to replace the feature point description algorithm of the original ORB to enhance the expressiveness and description efficiency of the image.Secondly,it adds rotational invariance to the BEBLID using the orientation information of the feature points.It also selects the rotationally stable bits in the BEBLID to further enhance the rotational invariance of the BEBLID.Finally,it retrains the binary visual dictionary based on the BEBLID to reduce the cumulative error of V-SLAM and improve the loading speed of the visual dictionary.Experiments show that the dictionary loading efficiency is improved by more than 10 times.The RB-SLAM algorithm improves the trajectory accuracy by 24.75%on the TUM dataset and 26.25%on the EuRoC dataset compared to the ORB-SLAM3 algorithm.

Design of a sector bowtie nano-rectenna for optical power and infrared detection

We designed a sector bowtie nanoantenna integrated with a rectifier （Au-TiOx-Ti diode） for collect- ing infrared energy. The optical performance of the metallic bowtie nanoantenna was numerically investigated at infrared frequencies （5-30 μm） using three-dimensional frequency-domain electro- magnetic field calculation software based on the finite element method. The simulation results indi- cate that the resonance wavelength and local field enhancement are greatly affected by the shape and size of the bowtie nanoantenna, as well as the relative permittivity and conductivity of the dielectric layer. The output current of the rectified nano-rectenna is substantially at nanoampere magnitude with an electric field intensity of 1 V/m. Moreover, the power conversion efficiency for devices with three different substrates illustrates that a substrate with a larger refractive index yields a higher efficiency and longer infrared response wavelength. Consequently, the optimized structure can pro- vide theoretical support for the design of novel optical rectennas and fabrication of optoelectronic devices.