Assessment of Wet Season Precipitation in the Central United States by the Regional Climate Simulation of the WRFG Member in NARCCAP and Its Relationship with Large-Scale Circulation Biases

Assessment of past-climate simulations of regional climate models(RCMs)is important for understanding the reliability of RCMs when used to project future regional climate.Here,we assess the performance and discuss possible causes of biases in a WRF-based RCM with a grid spacing of 50 km,named WRFG,from the North American Regional Climate Change Assessment Program(NARCCAP)in simulating wet season precipitation over the Central United States for a period when observational data are available.The RCM reproduces key features of the precipitation distribution characteristics during late spring to early summer,although it tends to underestimate the magnitude of precipitation.This dry bias is partially due to the model’s lack of skill in simulating nocturnal precipitation related to the lack of eastward propagating convective systems in the simulation.Inaccuracy in reproducing large-scale circulation and environmental conditions is another contributing factor.The too weak simulated pressure gradient between the Rocky Mountains and the Gulf of Mexico results in weaker southerly winds in between,leading to a reduction of warm moist air transport from the Gulf to the Central Great Plains.The simulated low-level horizontal convergence fields are less favorable for upward motion than in the NARR and hence,for the development of moist convection as well.Therefore,a careful examination of an RCM’s deficiencies and the identification of the source of errors are important when using the RCM to project precipitation changes in future climate scenarios.

Designing a Protection Scheme in Micro-Grid Systems with DG Using Central Protection Unite and Multiple Setting Group Protection Relays

Distributed generators now is widely used in electrical power networks, in some cases it works seasonally, and some types works at special weather conditions like photo voltaic systems and wind energy, and due to this continuous changes in generation condition, the fault current level in network will be affected, this changes in fault current level will affect in the coordination between protection relays and to keep the coordination at right way, an adaptive protection system is required that can adaptive its setting according to generation changes, the fault current level in each case is evaluated using ETAP software, and the required relay setting in each case is also evaluated using Grey Wolf Optimizer (GWO) algorithm, and to select suitable setting which required in each condition, to select the active setting group of protection relay according to generation capacity, central protection unite can be used, and to improve protection stability and minimizing relays tripping time, a proposed method for selecting suitable backup relay is used, which leads to decrease relays tripping time and increase system stability, output settings for relays in all cases achieved our constrains.

A New Model for a New Central Purchasing Unit for Health Products to Support Reaching the Objectives of a Lasting Development and Facing Sanitary Crisis

Medicines are a global, strategic and diplomatic issue [1]. The UN General Secretary’s High Level Task Force [2] on Access to Medicines calls for a new approach to reduce the gap between medical innovations and access to medicines. Inequality in access to quality pharmaceutical products in a framework of global health democracy poses a threat to the ethical and equitable management of the provision of quality health care, particularly during global health crises. In French-speaking Africa, the lack of a unified production of pharmaceutical medicines forces wholesalers （public and private） to import almost all of their medicine demands resulting in a risk of dependence and major pharmaceutical quality defects. These central purchasing units are therefore often faced with the major challenge of guaranteeing the performance of their services and the security of their supplies. In order to achieve component 3 （“Access to Health”） of the SDOs （sustainable development goals）, in particular the access to affordable medicines, it is essential for a country to have a strategy of pharmaceutical independence [3] by anticipating the epidemiological transition and the management of health crises. This strategy of pharmaceutical independence is based in the short and medium term on the strengthening of central purchasing units and the establishment of a public-private partnership between central purchasing units and wholesalers, and in the long term on the establishment of competitive production units that comply with international standards. However, recent health crises have shown the fragility of public central purchasing units and make it difficult to anticipate health crises.

A new approach for real time object detection and tracking on high resolution and multi-camera surveillance videos using GPU

High resolution cameras and multi camera systems are being used in areas of video surveillance like security of public places, traffic monitoring, and military and satellite imaging. This leads to a demand for computational algorithms for real time processing of high resolution videos. Motion detection and background separation play a vital role in capturing the object of interest in surveillance videos, but as we move towards high resolution cameras, the time-complexity of the algorithm increases and thus fails to be a part of real time systems. Parallel architecture provides a surpass platform to work efficiently with complex algorithmic solutions. In this work, a method was proposed for identifying the moving objects perfectly in the videos using adaptive background making, motion detection and object estimation. The pre-processing part includes an adaptive block background making model and a dynamically adaptive thresholding technique to estimate the moving objects. The post processing includes a competent parallel connected component labelling algorithm to estimate perfectly the objects of interest. New parallel processing strategies are developed on each stage of the algorithm to reduce the time-complexity of the system. This algorithm has achieved a average speedup of 12.26 times for lower resolution video frames(320×240, 720×480, 1024×768) and 7.30 times for higher resolution video frames(1360×768, 1920×1080, 2560×1440) on GPU, which is superior to CPU processing. Also, this algorithm was tested by changing the number of threads in a thread block and the minimum execution time has been achieved for 16×16 thread block. And this algorithm was tested on a night sequence where the amount of light in the scene is very less and still the algorithm has given a significant speedup and accuracy in determining the object.

Implementing Delay Multiply and Sum Beamformer on a Hybrid CPU-GPU Platform for Medical Ultrasound Imaging Using Open MP and CUDA

Anovel beamforming algorithmnamed Delay Multiply and Sum(DMAS),which excels at enhancing the resolution and contrast of ultrasonic image,has recently been proposed.However,there are nested loops in this algorithm,so the calculation complexity is higher compared to the Delay and Sum(DAS)beamformer which is widely used in industry.Thus,we proposed a simple vector-based method to lower its complexity.The key point is to transform the nested loops into several vector operations,which can be efficiently implemented on many parallel platforms,such as Graphics Processing Units(GPUs),and multi-core Central Processing Units(CPUs).Consequently,we considered to implement this algorithm on such a platform.In order to maximize the use of computing power,we use the GPUs andmulti-core CPUs inmixture.The platform used in our test is a low cost Personal Computer(PC),where a GPU and a multi-core CPU are installed.The results show that the hybrid use of a CPU and a GPU can get a significant performance improvement in comparison with using a GPU or using amulti-core CPU alone.The performance of the hybrid system is increased by about 47%–63%compared to a single GPU.When 32 elements are used in receiving,the fame rate basically can reach 30 fps.In the best case,the frame rate can be increased to 40 fps.

Mechanism of Fast Data Retransmission in CU-DU Split Architecture of 5G NRG

The 5G radio access network （RAN） architectm＇e is supposed to be split into the central unit （CU） and the distributed unit （DU） in order to support more flexible transport networks and provide enhanced user experience. However, such functional split may also introduce some new technical issues. In this pa- per, we study the data fast retransmission issue introduced by this functional split in different scenarios and solutions are provided to handle this issue. With the fast data retransmis- sion mechanism proposed in this paper, the retransmitted da- ta packets could be identified and handled with high priority. In this way, the data delivery between the CU and DU in 5G RAN is assured.

基于负载均衡的CPU-GPU异构计算平台任务调度策略

针对中央处理单元-图形处理单元(central processing unit-graphics processing unit,CPU-GPU)异构计算系统中,CPU和GPU负载不均导致系统性能降低的问题,提出了一种基于队列的混合调度策略.该策略通过探测获得CPU和GPU处理指定任务的计算能力,将计算任务按照探测比例分配给CPU和GPU;将并行任务存入双向队列,以降低调度带来的额外开销.结果表明,使用该策略的基准测试程序系统性能平均提升了28.07%.总体而言,该调度策略能够缩短CPU与GPU完成各自计算任务后的等待时间,有效平衡系统CPU与GPU之间的负载,提升系统性能.

Delicate chemical structure regulation of nonfullerene acceptor for efficient and large thickness organic solar cells

Inspired by the success of CH-series acceptors, a small-molecular acceptor, CH-Tz was reported by adopting a new conjugationextended electron-deficient unit([1,2,5]thiadiazolo[3,4-b]pyrazine) on the central core. Owing to the enhanced inter-/intramolecular interactions, CH-Tz exhibited near-infrared absorption and an effective three-dimensional molecular packing network in its single crystal. When blended with polymer donor PM6, the binary device achieved a high power conversion efficiency(PCE) of 18.54%, with a notable short-circuit current density(J_(sc)) of 27.54 m A cm-2and an excellent fill factor(FF) over 80%,which can be partly ascribed to the balanced charge transport properties in the blend film. After employing D18-Cl as the third component, an enhanced PCE of 18.85% was achieved due to a more obvious fiber network. Impressively, the CH-Tz-based OSC devices show excellent thermal stability and thickness insensitivity. Record-breaking Jscof 28.92 m A cm-2was reached for PM6:D18-Cl:CH-Tz ternary device with a thickness of 560 nm. Besides, CH-Tz shows potential in fabricating multicomponent high-performance organic solar cells, where over 19% efficiency could be realized in the quaternary device. Our work advances the strong influence of electron-deficient central units on molecular photovoltaic properties and guides the design of acceptors for stable and large-thickness organic solar cells.

Lowing the energy loss of organic solar cells by molecular packing engineering via multiple molecular conjugation extension

The central unit(benzo[c][1,2,5]thiadiazole) in Y6 series of molecules plays a determining role in their unique intermolecular packing for a three-dimensionally(3D) network, largely endowing their organic solar cells(OSCs) with so far the best power conversion efficiencies(PCEs) and also largely suppressed energy losses(Eloss). Despite its vital role in molecular packing, very few explorations for central unit have been conducted due to possibly the constructing challenge of central heterocyclic units.Herein, a highly efficient acceptor-donor-acceptor(A-D-A) type electron acceptor, CH17, has been designed and constructed,featured with a prominent π extension in both directions of the central and end units with respect to Y6 series. Such a multiple and much enhanced conjugation extension in CH17 enables a much more effective and compact 3D molecular packing compared with that of Y6 supported by X-ray single crystal and other analysis, mainly caused by a newly observed distinctive dual “end unit to central unit” packing mode. This much favorable molecular packing, also kept in its blends with donor materials, leads a larger electron and hole transfer integrals and hence much improved charge transport, and reduced energetic disorders in CH17blends. More importantly, the observed upshifted charge transfer(CT) state of CH17 blends compared with that of Y6, due to its increased molecular conjugation extension in both directions, further enhances the hybridization between its CT and local exciton(LE) states, resulting in higher luminescence efficiency, much suppressed non-radiative recombination loss and smaller Elosswith respect to that of Y6. Consequently, an excellent PCE of 17.84% is achieved with PM6 as the donor in a binary device compared with a PCE of 16.27% for the controlled Y6 device. Furthermore, a further improved PCE of 18.13% is achieved by CH17-based ternary single-junction OSCs along with a markedly reduced Elossof 0.49 e V and larger open-circuit voltage(Voc) of0.89 V, compared with that(16.27% of PCE, 0.85 V of Voc, and 0.53 e V of Eloss) of the control device using Y6. This significantly improved photovoltaic performance caused by molecular multiple conjugation extension, especially through the largely unexplored central unit, indicates that there is still much room to further enhance OSC performance by addressing the most important issue for OSC, i.e, the smaller Voccaused by larger Eloss, through engineering molecular packing by designing/tuning molecule more dedicatedly.

High efficiency ternary organic solar cells enabled by compatible dual-donor strategy with planar conjugated structures

Ternary organic solar cells(OSCs) have received extensive attention for improving the power conversion efficiency(PCE) of organic photovoltaics(OPVs). In this work, a novel donor material(ECTBD) consisting of benzodithiophene(BDT) central electron donor unit was developed and synthesized. The small molecular donor has the same central unit as PM6. The addition of ECTBD into PM6:Y6 system could improve the morphology of active blend layer. In addition, ECTBD showed good morphologically compatibility when blending with PM6:Y6 host, resulting in the improvement of fill factor and current density. As a result, the ternary devices based on PM6:ECTBD:Y6 ternary system achieved a highest PCE of 16.51% with fill factor of 76.24%, which was much higher than that of the binary devices(15.7%). Overall, this work provided an effective strategy to fabricate highly efficient ternary organic solar cells through design of the novel small molecular donor as the third component.