A Parallelizable Acceleration Framework for Packing Linear Programs

This paper presents an acceleration framework for packing linear programming problems where the amount of data available is limited, i.e., where the number of constraints m is small compared to the variable dimension n. The framework can be used as a black box to speed up linear programming solvers dramatically, by two orders of magnitude in our experiments. We present worst-case guarantees on the quality of the solution and the speedup provided by the algorithm, showing that the framework provides an approximately optimal solution while running the original solver on a much smaller problem. The framework can be used to accelerate exact solvers, approximate solvers, and parallel/distributed solvers. Further, it can be used for both linear programs and integer linear programs

A Practical Illustration of Methods to Deal with Potential Outliers: A Multiverse Outlier Analysis of Study 3 from Brummelman, Thomaes, Orobio de Castro, Overbeek, and Bushman (2014)

Recently, Brummelman, Thomaes, Orobio de Castro, Overbeek, and Bushman (2014: Study 3) demonstrated that inflated praise benefits challenge seeking of children with high self-esteem, but harms challenge seeking of children with low self-esteem. In the present paper, we examined the original data set on model-fit and prediction outliers according to various reasonable criteria and norms. Subsequently, we carried out a multiverse outlier re-analysis on the data of Brummelman and colleagues’ Study 3, employing the same analytical approach as the original authors did but excluding outliers. Out of the twelve re-analyses in the multiverse, six demonstrated that removing only a small number of outliers rendered the originally reported crucial interaction effect between self-esteem and type of praise non-significant and produced a sizeable reduction of the effect size. The present paper illustrates the use of reporting outlier analyses, which lies in allowing a critical evaluation of the empirical evidence and offering a more complete picture that enhances future studies in the field

Average capacity analysis of FSO system with Airy beam as carrier over exponentiated Weibull channels

Based on scintillation index of Airy beam and exponentiated Weibull channel model, analytical expressions of average channel capacity for free-space optical (FSO) communication links with Airy beam as signal carrier under weak atmospheric turbulence and on-off keying modulation scheme are derived. The average capacity at various propagation distances, transverse scale factors and exponential decay factors has been evaluated. And we compared the average capacity of FSO links with Airy beam and Gaussian beam as signal carrier. The results show that the average capacity of FSO links with Airy beam as carrier increases with the increase of mean signal-to-noise ratio and decreases uniformly with the increase of propagation distance. When the transverse scale factor of Airy beam is about 2 cm, a higher average capacity can be obtained. And the smaller the exponential decay factor of Airy beam, the larger the average capacity. Under the same source power or source width, the average capacity of FSO links with Airy beam as carrier is significantly higher than that of FSO links with Gaussian beam as carrier. The results of this research have some reference significance for the application of Airy beam in FSO communication system

Experimental Study on Properties of Ultrasonic Coupling Agent with Graphene in NDT

An ultrasonic coupling agent, as an acoustic medium between the ultrasonic probe and the surface of the specimens, is indispensable in Nondestructive Testing (NDT). Whether it is liquid, air, or solid coupling agent, the problem of improving the efficiency of ultrasonic propagation in a coupling agent is one worth studying. Glycerol and hydrogels are two common liquid coupling agents in NDT. This study intended to investigate the effect of graphene addition on the performance of these coupling agents in NDT. Firstly, based on the theory of acoustic impedance matching, the authors established an index system to evaluate the performance of ultrasonic coupling agent by experiments. Secondly, hydrogel–graphene and glycerol–graphene composite coupling agents were prepared by adding three-dimensional graphene structure powders with mass fraction of 0.25%, 0.5%, 0.75%, and 1% to CG-98 hydrogel coupling agent and HG-99 glycerol coupling agent, respectively. Corresponding experiments were conducted on these composite coupling agents. Peak-to-peak value, attenuation coefficient, and energy value of first echo are calculated at different frequencies. The experimental results showed that graphene can significantly improve the ultrasonic propagation performance of hydrogel and glycerin coupling agents. In addition, when the mass fraction of graphene added was 0.75%, the coupling agent had the best performance. Finally, we measured the acoustic impedance values of the composite couplings with different graphene contents to demonstrate the reliability of the experimental results

Experimental Study on Properties of Ultrasonic Coupling Agent with Graphene in NDT

An ultrasonic coupling agent, as an acoustic medium between the ultrasonic probe and the surface of the specimens, is indispensable in Nondestructive Testing (NDT). Whether it is liquid, air, or solid coupling agent, the problem of improving the efficiency of ultrasonic propagation in a coupling agent is one worth studying. Glycerol and hydrogels are two common liquid coupling agents in NDT. This study intended to investigate the effect of graphene addition on the performance of these coupling agents in NDT. Firstly, based on the theory of acoustic impedance matching, the authors established an index system to evaluate the performance of ultrasonic coupling agent by experiments. Secondly, hydrogel–graphene and glycerol–graphene composite coupling agents were prepared by adding three-dimensional graphene structure powders with mass fraction of 0.25%, 0.5%, 0.75%, and 1% to CG-98 hydrogel coupling agent and HG-99 glycerol coupling agent, respectively. Corresponding experiments were conducted on these composite coupling agents. Peak-to-peak value, attenuation coefficient, and energy value of first echo are calculated at different frequencies. The experimental results showed that graphene can significantly improve the ultrasonic propagation performance of hydrogel and glycerin coupling agents. In addition, when the mass fraction of graphene added was 0.75%, the coupling agent had the best performance. Finally, we measured the acoustic impedance values of the composite couplings with different graphene contents to demonstrate the reliability of the experimental results

Study on the Sustainable Planning and High Efficiency Utilization of Rural Areas Based on Ecological-Production-Living Space – A Case Study of Shuihu Village, Hengdong County, China

Rural planning is an important part of territorial spatial planning. The study of rural “Ecological-production-living Space” is the key part in optimizing the land spatial development and improving the spatial planning system, which is significant for the sustainable planning and for high efficiency utilization of rural areas. In this study we take Shuihu village, Hengdong County, China, as a case study. (1) The paper applies the Analytic Hierarchy Process to construct a multi-factor evaluation system of villages “Ecological-production-living Space” for their development and construction, agricultural production conditions and ecological function suitability. Establishing the hierarchy model of rural “Ecological-production-living Space” and affecting weight values to each evaluation factor. (2) Using GIS multi-factor grid, we comprehensively evaluate the village space and identify as well as its dominant function. In the plan, the agricultural production as the leading function and as ecological and living space accounts for 36.25% of the area of the village field. The ecological production accounted for 51.71%, the development and construction accounts for 9.67%. (3) Apply rural complex concept to guide space usage separately from the production space (production and living space) , ecological space (ecological living and ecological production space), living space (living ecology and production space) ecological production and living space, to improve the ecological conservation and energy efficiency of agricultural production, to build ecological agriculture, modern agriculture and liveable idyllic community. Through these above parts, we hope to achieve the sustainable development model of rural area and high efficiency utilization of land resources

Deep UV Laser at 249 nm Based on GaN Quantum Wells

Deep UV Laser at 249 nm Based on GaN Quantum Well