Reform of Practical Teaching of “Linux Operating System Fundamentals” Under the Background of Emerging Engineering Education

With the advancement of the construction of emerging engineering education,the reform of practical teaching has become an important task of higher engineering education.This article takes the course“Linux Operating System Fundamentals”as an example to explore practical teaching reform in the context of emerging engineering education.By analyzing the current situation and problems in course practical teaching,we proposed practical teaching reforms such as online experiments,practical content updates,project-based engineering practices,and diversified evaluation models,and designed corresponding implementation plans.Practice has proved that this reform can improve students’learning interest and engineering practical skills,and cultivate outstanding engineers with innovative spirit and practical skills.

Exploration on the Practice System of Computer Software Course under the New Engineering

The rapid development of information technology and the new economy is a challenge to the training of computer technology and engineering professionals. The cultivation of engineering talents in Computer Engineering under the new engineering is an important part of the construction and exploration of new engineering in universities. According to the teaching reform of computer specialty in the new engineering construction, starting from the practice of curriculum system of software, mainly discusses the basic ideas of practice teaching reform of the course of computer software, software engineering practice curriculum system and practice curriculum system implementation method. The basic ideas of teaching reform practice in the course of the software include: expanding computer professional students' knowledge, strengthening students' computer science and software engineering knowledge and engineering practice ability, strengthening the frontiers of computer science and technology guide. Software practice course system is divided into three levels, including basic language course, engineering basic professional practice course and the professional practice course of engineering application direction. The implementation method of engineering application practice curriculum system is discussed in detail, such as strengthening university-enterprise cooperation, introducing teachers of social training institutions and guiding students to participate in subject competition and innovation projects.

LMI approach for absolute stability of general neutral type Lurie indirect control systems

This paper deals with the problem of the absolute stability for general neutral type Lurie indirect control systems by Lyapunov method and linear matrix inequality （LMI） technique. Delay-dependent sufficient conditions for the absolute stability are derived and expressed as the feasibility problem of LMI, which can be easily solved by Matlab Toolbox. Finally, some examples are provide to demonstrate the effectiveness of proposed method.

Dynamics of land use change in a mining area:a case study of Nadowli District,Ghana

In a developing country like Ghana, the study of land use and land cover change(LULCC) based on satellite imageries still remains a challenge due to cost, resolution and availability with less skilled man power. Existing researches are skewed towards the southerly part of Ghana thereby leaving the Northern sectors uncovered. The maximum likelihood classification(MLC) algorithm was employed for the LULCC between 2000 and 2014 in Nadowli: an area characterized by an upsurge in mining in the Northern belt of Ghana. A spatial-social approach was utilized combining both satellite imagery and socio economic data. Land use transition matrix, land use integrated index/degree indices was used to depict the characters of the change. A semi structured interview, pair wise ranking and key informant interviews were used to correlate the socio economic impact of the different LULC. Overall changes in the landscape showed an increase in bare ground by 19.22%, open savannah by 16.8% whereas closed savanna decreased by 50%. Land use change matrix showed increasing trends of bare ground at the expense of vegetation. The integrated land use index highlighted the bare ground and built up areas rising with a decreasing closed vegetation woodlot. Large farm size are shrinking whiles majority of the people view mining as the main socio economic activity affecting the environment and the reduction in vegetation. This study therefore provides a strategic guide and a baseline data for land use policy actors in the Northern belt of Ghana. This will aid in developing models for future land use change implications in surrounding areas where mining is on the rise.

Alternative Fuzzy Cluster Segmentation of Remote Sensing Images Based on Adaptive Genetic Algorithm

Remote sensing image segmentation is the basis of image understanding and analysis. However,the precision and the speed of segmentation can not meet the need of image analysis,due to strong uncertainty and rich texture details of remote sensing images. We proposed a new segmentation method based on Adaptive Genetic Algorithm(AGA) and Alternative Fuzzy C-Means(AFCM) . Segmentation thresholds were identified by AGA. Then the image was segmented by AFCM. The results indicate that the precision and the speed of segmentation have been greatly increased,and the accuracy of threshold selection is much higher compared with traditional Otsu and Fuzzy C-Means(FCM) segmentation methods. The segmentation results also show that multi-thresholds segmentation has been achieved by combining AGA with AFCM.

Life Prediction Model of Machine Tool based on Deep Learning

In view of the shortage of traditional life prediction methods for machine tools,such as low accuracy of life prediction and few samples basis attributes,a life prediction model of machine tools combined with machine tool attributes is proposed.The life prediction model of machine tool adopts KL dispersion distribution theory,uses modal superposition method to carry out machine tool life analysis,calculates the theoretical life of machine tool,and then carries on the simulation,obtains the machine tool life prediction value.Compared with the traditional method of machine tool life prediction,the model is based on the application life fatigue damage model,which superimposes the service times and maintenance cycle of the machine tool,derives the influence factor of machine tool life,and obtains the linear relationship between the influence factor of machine tool life and the life of machine tool.The influence factor of machine tool life is introduced as the life prediction parameter of machine tool.The data transformation relationship of HT300 parts is constructed.The original part data is enhanced.The effective training set is obtained.The life prediction model of machine tool based on deep learning is completed.The quantitative analysis of machine tool life is carried out.The experiment of machine tool life prediction using training data set proves the validity of the model.Regression test was carried out on the training data set to reflect the robustness of the model.The prediction accuracy of the model is further verified by Weibull test.

An Adaptive Approach of Satellite Baseline Estimation in InSAR

Baseline is an important parameter of radar interferometry. Generally, it can be estimated by satellite orbital data or ground control points. In this paper, an adaptive method is proposed to estimate it with combination satellite orbital data, and the accuracy of baseline estimated can be improved without ground control points;actual data of ERS and ENVISAT ASAR have been used in algorithm development and the final obtained elevation shows that the precise orbit data is more accurate than original orbit data in estimating baseline.

A New Approach to Dense Spectrum Analysis of Infrasonic Signals

Spectrum analysis is very important in geological hazards of infrasonic signal observation systems.The spectrum of infrasonic signal is a dense spectrum which can leads to potential erroneous spectrum analysis.Hereby we propose a dense spectrum analysis algorithm combining all phase Fast Fourier Transform(apFFT)and Chirp Z-transform(CZT)to analyse dense low frequency signal.This is called all phase Chirp Z transform(apCZT).The apFFT spectrum analysis can reduce spectrum leakage,but does not enhance resolution while the CZT vice versa.The novel algorithm apCZT can suppress spectral leakage and improve the resolution at the same time.Simulation results demonstrate that the apCZT algorithm can distinguish the frequencies whose intervals are less than the ordinary frequency resolving power of Discrete Fourier Transform(DFT)and apFFT.The apCZT it is not only suitable for infrasonic signals but also in other dense spectrum analysis applications,such as voice,vibration,noise,electrocardiography,radar signals,power system harmonics and other engineering practice.

Modification and validation of a new method to improve the accuracy of MODIS-derived dew point temperature over China's Mainland

MODIS atmospheric profile products(MOD07_L2 and MYD07_L2)have been widely used for near-surface dew point temperature(T_(d))estimation.However,their accuracy over large scale has seldom been evaluated.In this study,we validated these two products comprehensively against 2153 stations over China's Mainland.MOD07_L2 was suggested by our study because it achieved higher accuracy in either of two frequently-used methods.To be specific,the root-meansquare error(RMSE)achieved by MOD07_L2 and MYD07_L2 was 5.82 and 7.42℃,respectively.On this basis,a recent ground-based correction method was modified to further improve their accuracy.Our focus is to investigate whether this ground-based approach is applicable to large-scale remote sensing applications.The results show that this new method showed great potential for T_(d) estimation independently from ground observations.Through the introduction of MODIS land surface products,the RMSE it achieved for MOD07_L2 and MYD07_L2 was 5.23 and 5.59℃,respectively.Further analysis shows that it was particularly useful in capturing the annual average T_(d) patterns.The R2,RMSE,and bias of annual average daily mean T_(d) estimates were 0.95,1.84℃,and 0.53℃,and those achieved for annual average instantaneous T_(d) estimates were 0.94,2.09℃,and 0.75℃,respectively.

Wetting characteristics of the hydrophobic material surface through condensation

Composite insulators are generally considered to have excellent anti-pollution flashover performance,but recently there has been a flashover accident on the indoor clean insulator in China,which is suspected to be related to the wetting of insulators through condensation.Therefore,this paper studied the water condensation on hydrophobic surfaces.The changes in the mass,length,and proportion of the water droplets on the hydrophobic surface during the wetting process were measured,and the influence of wetting degree on the flashover characteristics was studied.It was found that the insulator surface temperature lower than the dew point is a prerequisite for the wetting of the clean hydrophobic surface,and the wetting velocity increases with the electric field.The results could provide some reference for understanding the insulator flashover accidents.

Automatic mapping of lunar landforms using DEM-derived geomorphometric parameters

Developing approaches to automate the analysis of the massive amounts of data sent back from the Moon will generate significant benefits for the field of lunar geomorphology. In this paper, we outline an automated method for mapping lunar landforms that is based on digital terrain analysis. An iterative self-organizing （ISO） cluster unsupervised classification enables the automatic mapping of landforms via a series of input raster bands that utilize six geomorphometric parameters. These parameters divide landforms into a number of spatially extended, topographically homogeneous segments that exhibit similar terrain attributes and neighborhood properties. To illustrate the applicability of our approach, we apply it to three representative test sites on the Moon, automatically presenting our results as a thematic landform map. We also quantitatively evaluated this approach using a series of confusion matrices, achieving overall accuracies as high as 83.34% and Kappa coefficients （K） as high as 0.77. An immediate version of our algorithm can also be applied for automatically mapping large-scale lunar landforms and for the quantitative comparison of lunar surface morphologies.

中国1960-2016年风能资源的时空分布特征

基于462个气象观测站1960–2016年共57年的近地面风速日资料,利用克里格空间内插,最小二乘法,相关系数检验和经验正交函数分解(EOF)等方法分析了年均和各个季节中国区域风速及有效风能密度的时空变化特征。研究结果表明:在中国北部和部分沿海地区年平均风速在3 m s-1以上,有效风能密度在75 W m-2以上,而在中国南部地区平均风速和有效风能密度均较小。近五十多年以来,中国区域年均和季节平均风速呈明显下降趋势,北部地区春季递减率最大,沿海地区冬季递减率最大。广东部分地区年平均风速有增大的趋势,西南,华南和华中西部地区年平均风速变化不大。平均风速大的区域,递减率也大。年平均风速和年有效风能密度的主要空间分布模态表现出高度的一致性,均呈现逐年减小趋势。中国风速及风能资源的减小趋势,主要与全球变暖及土地利用变化有关。

Pharmacodynamic study on insomnia-curing effects of Shuangxia Decoction in Drosophila melanogaster

The present study aimed to establish a pharmacodynamic method using the py Solo software to explore the influence of freeze-dried powders of Shuangxia Decoction(SXD) on the sleep of normal Drosophila melanogaster and the Drosophila melanogaster whose sleep was divested by light. The dose-effect and the time-effect relationships of SXD on sleep were examined. The effect-onset concentration of SXD was 0.25%, the plateau appeared at the concentration of 2.5% and the total sleep time showed a downtrend when the concentration was greater than 2.5%. The sleep time was the longest on the fourth day after SXD was given. The fruit fly sleep deprivation model was repeated by light stimulation at night. The middle dosage group(2.5%) had the best insomnia-curing effect. In conclusion, using the py Solo software, an approach for the pharmacodynamics study was established with Drosophila melanogaster as a model organism to determine the insomnia-curing effects of the traditional Chinese medicine(TCM). Our results demonstrated the reliability of this method. The freeze-dried powders of SXD could effectively improve the sleep quality of Drosophila melanogaster.

Stratigraphic Architecture and Computer Modelling of Carbonate Platform Margin,Late Ordovician Lianglitage Formation,Central Tarim Basin

According to the different geometries and reflected characteristics in the seismic sections, the carbonate platform margin of the northern slope can be summarized as three basic depositional architectures in the Late Ordovician Lianglitage （良里塔格） Formation of the Tazhong （塔中） uplift. The type one mainly located in the west of the carbonate platform margin, and it showed obvious imbricate progradation from the interior to the margin of the platform. The type two was in the middle of the carbonate platform margin, which showed retrogradational stacking pattern in the same transgres- sive systems tract period, and the slope strata of the platform margin showed progradational sequence in the highstand systems tract period. The type three located in the east of the carbonate platform margin, and it showed the parallel aggradational architecture. The crossing well section along the northern slope of the Tazhong carbonate platform showed that the depositional thickness became thinner from the east to the west. The thickest belt located in the east of the platform margin, and became thinner rapidly towards the basin and the platform interior. These indicated that the paleogeomorphology ofthe Tazhong uplift was probably high in the west and low in the east during the period of the Late Ordovician Lianglitage Formation. According to the interpretation of seismic profiles and the computer modelling result, the depositional architectures of sequence O31-2 showed aggradation, retrogradation and progradation from the east to the west of the carbonate platform margin during the transgression period. This meant that the accommodation became smaller gradually from the east to the west along the northern carbonate platform margin of the Tazhong uplift.The difference of the accommodation was probably caused by the difference of tectonic subsidence. Also, computer-aided modelling can be used to deeply understand the importance of various control parameters on the carbonate platform depositional architectures and processes.

ACCURACY ENHANCEMENT FOR THE SIGNORINI PROBLEM WITH FINITE ELEMENT METHOD

In this paper,we study the accuracy enhancement for the frictionless Signorini problem on a polygonal domain with linear finite elements.Numerical test is given to verify our result.

Typhoon storm surge ensemble forecast based on GPU technique

The accuracy of typhoon forecasts plays an important role in the prediction of storm surges.The uncertainty of a typhoon’s intensity and track means it is necessary to use an ensemble model to predict typhoon storm surges.A hydrodynamic model,which is operational at the National Marine Environmental Forecasting Center,is applied to conduct surge simulations for South China coastal areas using the best track data with parametric wind and pressure models.The results agree well with tidal gauge observations.To improve the calculation efficiency,the hydrodynamic model is modified using CUDA Fortran.The calculation results are almost the same as those from the original model,but the calculation time is reduced by more than 99%.A total of 150 typhoon cases are generated by combining 50 typhoon tracks from the European Centre for Medium-Range Weather Forecasts with three possible typhoon intensity forecasts.The surge ensembles are computed by the improved hydrodynamic model.Based on the simulated storm surges for the different typhoon cases,ensemble and probability forecast products can be provided.The mean ensemble results and probability forecast products are shown to agree well with the observed storm surge caused by Typhoon Mangkhut.The improved model is highly suitable for ensemble numerical forecasts,providing better forecast products for decision-making,and can be easily implemented to run on regular workstations.

Analyzing and De-Anonymizing Bitcoin Networks:An IP Matching Method with Clustering and Heuristics

The anonymity and de-anonymity of blockchain and Bitcoin have always been a hot topic in blockchain related research.Since Bitcoin was created by Nakamoto in 2009,it has,to some extent,deviated from its currency attribute as a trading medium but instead turned into an object for financial investment and operations.In this paper,the power-law distribution that the Bitcoin network obeys is given with mathematical proof,while traditional deanonymous methods such as clustering fail to satisfy it.Therefore,considering the profit-oriented characteristics of Bitcoin traders in such occasion,we put forward a de-anonymous heuristic approach that recognizes and analyzes the behavioral patterns of financial High-Frequency Transactions(HFT),with realtime exchange rate of Bitcoin involved.With heuristic approach used for de-anonymity,algorithm that deals with the adjacency matrix and transition probability matrix are also put forward,which then makes it possible to apply clustering to the IP matching method.Basing on the heuristic approach and additional algorithm for clustering,finally we established the de-anonymous method that matches the activity information of the IP with the transaction records in blockchain.Experiments on IP matching method are applied to the actual data.It turns out that similar behavioral pattern between IP and transaction records are shown,which indicates the superiority of IP matching method.

Recent Developments in Magnetron Sputtering

The principle of magnetron sputtering is introduced andthe balanced and unbalanced magnetrons are compared andthe necessity of unbalanced magnetrons is explained as well. Several recent developments in plasma magnetron sputtering, i.e., unbalanced magnetron sputtering, pulsed magnetron sputtering and ion assisted sputtering, are discussed. The recent developments of unbalanced magnetron systems and their incorporation with ion sources result in an understanding in growingimportance of the magnetron sputtering technology, which makes the technology an applicable deposition process for a variety of important films, such as wear-resistant films and decorative films.

Geospatial assessment of rooftop solar photovoltaic potential using multi-source remote sensing data

Rooftop solar photovoltaics (PV) play increasing role in the global sustainable energy transition. This raises the challenge of accurate and high-resolution geospatial assessment of PV technical potential in policymaking and power system planning. To address the challenge, we propose a general framework that combines multi-resource satellite images and deep learning models to provide estimates of rooftop PV power generation. We apply deep learning based inversion model to estimate hourly solar radiation based on geostationary satellite images, and automatic segmentation model to extract building footprint from high-resolution satellite images. The framework enables precise survey of available rooftop resources and detailed simulation of power generation on an hourly basis with a spatial resolution of 100 m. The case study in Jiangsu Province demonstrates that the framework is applicable for large areas and scalable between precise locations and arbitrary regions across multiple temporal scales. Our estimates show that rooftop resources across the province have a potential installed capacity of 245.17 GW, corresponding to an annual power generation of 290.66 TWh. This highlights the huge space for carbon emissions reduction through developing rooftop PVs.