Predicting running time of aerodynamic jobs in HPC system by combining supervised and unsupervised learning method

Improving resource utilization is an important goal of high-performance computing systems of supercomputing centers.To meet this goal,the job scheduler of high-performance computing systems often uses backfilling scheduling to fill short-time jobs into job gaps at the front of the queue.Backfilling scheduling needs to obtain the running time of the job.In the past,the job running time is usually given by users and often far exceeded the actual running time of the job,which leads to inaccurate backfilling and a waste of computing resources.In particular,when the predicted job running time is lower than the actual time,the damage caused to the utilization of the system’s computing resources becomes more serious.Therefore,the prediction accuracy of the job running time is crucial to the utilization of system resources.The use of machine learning methods can make more accurate predictions of the job running time.Aiming at the parallel application of aerodynamics,we propose a job running time prediction framework SU combining supervised and unsupervised learning and verify it on the real historical data of the high-performance computing systems of China Aerodynamics Research and Development Center(CARDC).The experimental results show that SU has a high prediction accuracy(80.46%)and a low underestimation rate(24.85%).

Time’s Running Out

OIL-RICH Libya faces an array of daunting challenges in dealing with the legacies of Muammar Gaddafl＇s 42 years in power, not least the dysfunctional labor sector he left behind. Add to this the damage done to the country＇s economic infrastructure during the revolution that ousted Gaddafi in 2011, and the impact of the civil war that has raged for nearly a year. and the prognosis looks very grim,

On the Convergence of the Dual-Pivot Quicksort Process

Sorting an array of objects such as integers, bytes, floats, etc is considered as one of the most important problems in Computer Science. Quicksort is an effective and wide studied sorting algorithm to sort an array of n distinct elements using a single pivot. Recently, a modified version of the classical Quicksort was chosen as standard sorting algorithm for Oracles Java 7 routine library due to Vladimir Yaroslavskiy. The purpose of this paper is to present the different behavior of the classical Quicksort and the Dual-pivot Quicksort in complexity. In Particular, we discuss the convergence of the Dual-pivot Quicksort process by using the contraction method. Moreover we show the distribution of the number of comparison done by the duality process converges to a unique fixed point.

The Elaboration of Flow Resistance Model for a Bag Filter Serving a 200 MW Power Plant

On the basis of a macro flow resistance method and the Darcy Theory,a mathematical model is elaborated to characterize the flow resistance of a bag filter serving a coal-fired power plant.The development of the theoretical model is supported through acquisition of relevant data obtained by scanning the micro structure of the bag filter by means of an electron microscope.The influence of the running time and boiler load on the flow resistance and the impact of the flow resistance on the efficiency of the induced draft fan are analyzed by comparing the results of on-site operation tests.We show that the initial operation time and the table operation time are linearly related to the flow resistance of the bag filter;with the increase of boiler load,the flow resistance of the bag filter rises approximately as a quadratic function;with the rise of resistance,the power consumption of the induced draft fan increases while the efficiency of the induced draft fan decreases.

The Underground Water Level Simulation in Imamzadeh Jafar Plateau by the Use of Mudflow Software

The most secure method in providing water in the dry and semi-dry regions is the use of underground water sources and due to over consumption of water aquifers capacities, most of fields and specially Imamzadeh Jafar are faced with negative performance and balance, which threatens the land subsiding. The plateau with the annual raining of 438 millimeters has 169 deep and semi-deep wells with annual 36.68 million consumption and this issue has increased the research signification, in order to protect and relive the required water aquifers, there is a need to predict the underground water level accurately in different condition. In this research, by the use of balance equation and modflow software in Imamzadeh Jafar, water aquifer was analyzed within seven scenario. The underground water level evaluation for the short run periods for 2 years and middle term of 4 years and 12 years of long term was performed;and the results showed that the performance and balance of the plateau was increased due to increase of water consumption compared to the water aquifer quantity in the region that was negative. To the point that the 1, 3, 4, 5, 7 scenarios (minimum 0.17 and maximum -11.34) and 2, 6 scenarios in different timely periods show that the underground water saving volume is positive (minimum 3.64 and maximum 19.83).

TIME RUNNING OUT FOR NATIONAL TREASURES

Along with UNESCO proclaimed intangible cultural heritage, China has a national list of intangible cultural heritage with 518 entries.These intangi- ble national treasures are facing their toughest challenge to date in the ongo- ing fight against the unrelenting drive of urbanization and globalization. Without urgent attention many of these aspects of China’s rich history could be lost forever.Here we bring you a brief introduction of six art forms that, among many others,need protection.

Time Running Out for Africa's Great Apes

享誉世界的非洲黑猩猩研究学者和保护者Jane Goodall最近重访四十年前的研究基地,东非的坦桑尼亚。她的所见所闻令她悲哀,同时,本文的第一、二段所形成的鲜明对比,也让读者悲从中来: 40年之前:she could climb to a hilltop and see nothing but rain forest andchimpanzee habitat stretching to the horizon. 40年之后:…only a tiny piece of its old size,about ten miles long andthree miles deep,surrounded by cleared land and eroding soil. 20世纪初,非洲黑猩猩的数量估计近二百万,而今只有二十万左右！ 下面这句道出了非洲黑猩猩数量锐减的根本原因: As loggong companies push into the rain forests,their roads give ruthlesshunters access to chimp populations,which they kill for the lucrative(有利的)trade in bush meat. 可悲的是,much of the meat ends up in upscale(高消费阶层的)restaurantsin African cities. 遗憾的是,the chimpanzee’s greatest liabilities(不利条件)was its inability(无能)to adapt to new habitats.

MODELING AND PREDICTION CONCERNING TIME SERIES OF FLOOD/DROUGHT RUNS USING THE SELF-EXCITING THRESHOLD AUTOREGRESSIVE MODEL

When linear regressive models such as AR or ARMA model are used for fitting and predicting climatic time series,results are often not sufficiently good because nonlinear variations in the time series.In this paper, a nonlinear self-exciting threshold autoregressive(SETAR)model is applied to modeling and predicting the time series of flood/drought runs in Beijing,which were derived from the graded historical flood/drought records in the last 511 years(1470—1980).The results show that the modeling and predicting with the SETAR model are much better than that of the AR model.The latter can predict the flood/drought runs with a length only less than two years,while the formal can predict more than three-year length runs.This may be due to the fact that the SETAR model can renew the model according to the run-turning points in the process of predic- tion,though the time series is nonstationary.

Fast algorithms of public key cryptosystem based on Chebyshev polynomials over finite field

The computation of Chebyshev polynomial over finite field is a dominating operation for a public key cryptosystem.Two generic algorithms with running time of have been presented for this computation：the matrix algorithm and the characteristic polynomial algorithm,which are feasible but not optimized.In this paper,these two algorithms are modified in procedure to get faster execution speed.The complexity of modified algorithms is still,but the number of required operations is reduced,so the execution speed is improved.Besides,a new algorithm relevant with eigenvalues of matrix in representation of Chebyshev polynomials is also presented,which can further reduce the running time of that computation if certain conditions are satisfied.Software implementations of these algorithms are realized,and the running time comparison is given.Finally an efficient scheme for the computation of Chebyshev polynomial over finite field is presented.