Quantum speed-up capacity in different types of quantum channels for two-qubit open systems

A potential acceleration of a quantum open system is of fundamental interest in quantum computation, quantum communication, and quantum metrology. In this paper, we investigate the ＂quantum speed-up capacity＂ which reveals the potential ability of a quantum system to be accelerated. We explore the evolutions of the speed-up capacity in different quantum channels for two-qubit states. We find that although the dynamics of the capacity is varying in different kinds of channels, it is positive in most situations which are considered in the context except one case in the amplitude-damping channel. We give the reasons for the different features of the dynamics. Anyway, the speed-up capacity can be improved by the memory effect. We find two ways which may be used to control the capacity in an experiment： selecting an appropriate coefficient of an initial state or changing the memory degree of environments.

Transportation Infrastructure and Productivity Growth:Effects of Railway Speed-Up on Firm's TFP in China

Improvement of transportation infrastructure quality will lead to more sufficient market competition and promote the flow of resources with greater efficiency. This paper considers China's railway speed-up in 2007 as a quasi-natural experiment on China's transportation infrastructure quality improvement. With the initial operation of electric multiple units(EMUs) as the basis of grouping, this research examines the effect of railway speed-up on corporate total factor productivity(TFP) growth by the differencein-differences(DID) method. Overally, the results reveal positive effects both on firms' technological change and efficiency improvement, which lead to the increase of TFP. Based on subsamples divided by different regions and types of enterprises, further analysis indicates that the productivity of exporter, non-state and coastal firms has been mostly affected by the railway speed-up. These conclusions are verified by a placebo test. Besides, firms within "one-hour economic circle" have been shown more sensitive to the effect of railway speed increase.

Wheel Profile Optimization of Speed-up Freight Train Based on Multi-population Genetic Algorithm

The geometric shape of the wheel tread is mathematically expressed,and geometric parameters affecting the shape of the wheel were extracted as design variables.The vehicle dynamics simulation model was established based on the vehicle suspension parameters and track conditions of the actual operation,and the comprehensive dynamic parameters of the vehicle were taken as the design objectives.The matching performance of the wheel equivalent conicity with the vehicle and track parameters was discussed,and the best equivalent conicity was determined as the constraint condition of the optimization problem;a numerical calculation program is written to solve the optimization model based on a multi-population genetic algorithm.The results show that the algorithm has a fast calculation speed and good convergence.Compared with the LM profile,the two optimized profiles effectively reduce the wheelset acceleration and improve the lateral stability of the bogie and vehicle stability during straight running.Due to the optimized profile increases the equivalent conicity under larger lateral displacement of the wheelset,the lateral wheel-rail force,derailment coefficient,wheel load reduction rate,and wear index are reduced when the train passes through the curve line.This paper provides a feasible way to ensure the speed-up operation of a freight train.

Adobe Reader Speed-Up

软件点评：顾名思义，Adobe Reader Speed-up(www.tnk-bootblock couk)是一款用来加速Adobe Reader的工具，细心的用户肯定会注意到，如果启动电脑后首次运行Adobe Reader，它会加载一大堆插件（在Adobe Reader被称为增效工具），几乎要等上1分多钟才能真正看到你想看的PDF文档。

CCH-based geometric algorithms for SVM and applications

The support vector machine （SVM） is a novel machine learning tool in data mining. In this paper, the geometric approach based on the compressed convex hull （CCH） with a mathematical framework is introduced to solve SVM classification problems. Compared with the reduced convex hull （RCH）, CCH preserves the shape of geometric solids for data sets; meanwhile, it is easy to give the necessary and sufficient condition for determining its extreme points. As practical applications of CCH, spare and probabilistic speed-up geometric algorithms are developed. Results of numerical experiments show that the proposed algorithms can reduce kernel calculations and display nice performances.

Quantum Algorithm for Appointment Scheduling

Suppose a practical scene that when two or more parties want to schedule anappointment, they need to share their calendars with each other in order to make itpossible. According to the present result the whole communication cost to solve thisproblem should be their calendars’ length by using a classical algorithm. In this work, weinvestigate the appointment schedule issue made by N users and try to accomplish it inquantum information case. Our study shows that the total communication cost will bequadratic times smaller than the conventional case if we apply a quantum algorithm in theappointment-scheduling problem.

浅谈京广线郑州至武汉间提速消除限速区段的必要性

研究目的:京广线作为我国南北运输的主要通道,在客货运输中起着国民经济大动脉作用,而位于京广线中段的郑州至武汉间铁路在路网中的作用更是举足轻重。消除郑州至武汉间仅存的两个限速区段,提高郑武全段乃至京广全线的通过能力及客货列车运行速度,进一步适应客货运输的发展需求,提高铁路在运输市场的竞争力。研究方法:通过分析郑州至武汉间铁路历经6次大提速改造之后仍然存在的主要薄弱环节:运输能力紧张,运输数量不能适应发展需求及运行速度偏低,运输质量不能满足市场需求等,论证消除限速区段的必要性; 通过对两个限速区段改造方案的研究,论证消除限速区段的可行性。研究结果:消除郑州至武汉间孟庙——人和站南及长台关——陈家河间两个限速区段技术上是可行的,经济上是合理的。研究结论:消除孟庙——人和站南限速区段对长台关——陈家河段同时实施落坡及提速改线工程,既能满足郑州至武汉间全段客车提速的要求,也能适应既有线未来大量货物列车的运输需求,宜尽早实施。

A preliminary evaluation of high-performance advanced regional eta-coordinate model(H-AREM)

This paper preliminarily evaluates the speedup,scalability,and prediction skill of the highperformance advanced regional eta coordinate model（H-AREM）,which is based on several parallel processing methods and decomposition strategies.Results show that the parallel version of the model that is based on a modular parallel framework and a multidimensional domain decomposition strategy performs better overall,e.g.it is faster and more scalable than the version based on a message passing interface and a one-dimensional decomposition strategy.In particular,the scalability of the H-AREM with a resolution of 8 km approaches 8099 cores.Moreover,in the H-AREM,higher resolutions result in more realistic precipitation predictions without remarkable increases in simulation time.

GPU-accelerated phase field simulation of directional solidification

The phase field simulation has been actively studied as a powerful method to investigate the microstructural evolution during the solidification.However,it is a great challenge to perform the phase field simulation in large length and time scale.The developed graphics processing unit(GPU)calculation is used in the phase filed simulation,greatly accelerating the calculation efficiency.The results show that the computation with GPU is about 36 times faster than that with a single Central Processing Unit(CPU)core.It provides the feasibility of the GPU-accelerated phase field simulation on a desktop computer.The GPU-accelerated strategy will bring a new opportunity to the application of phase field simulation.

A Configurable Circuit for Cross-Correlation in Real-Time Image Matching

Cross-correlation （CC） is the most time-consuming in the implementation of image matching algorithms based on the correlation method. Therefore, how to calculate CC fast is crucial to real-time image matching. This work reveals that the single cascading multiply-accumulate （CAMAC） and concurrent multiply-accumulate （COMAC） architectures which have been widely used in the past, actually, do not necessarily bring about a satisfactory time performance for CC. To obtain better time performance and higher resource efficiency, this paper proposes a configurable circuit involving the advantages of CAMAC and COMAC for a large amount of multiply-accumulate （MAC） operations of CC in exhaustive search. The proposed circuit works in an array manner and can better adapt to changing size image matching in real-time processing. Experimental results demonstrate that this novel circuit which involves the two structures can complete vast MAC calculations at a very high speed. Compared with existing related work, it improves the computation density further and is more flexible to use.