检索结果-南通市图书馆

Mining Patterns from Change Logs to support Reuse-Driven Evolution of software Architectures

在线全文

学校读者我要写书评

暂无评论

Journal of Computer science & Technology 2018年第6期33卷 1278-1306页

作者： Aakash Ahlnad Claus Pahl Ahmed b. Altamimi Abdulrahman Alreshidi College of Computer science and Engineering University of Ha'il Ha'il 2440 Saudi Arabia Faculty of Computer science Free University of Bozen-Bolzano Bozen-Bolzano 39100 Italy

Modern software systems are subject to a continuous evolution under frequently varying requirements andchanges in systems＇ operational environments. Lehman＇s law of continuing change demands for long-living and continuouslyevolving software to prolong its productive life and economic value by accommodating changes in existing software. Reusableknowledge and practices have proven to be successful for continuous development and evolution of the software effectivelyand efficiently. However, challenges such as empirical acquisition and systematic application of the reusable knowledge andpractices must be addressed to enable or enhance software evolution. We investigate architecture change logs -- mininghistories of architecture-centric software evolution -- to discover change patterns that 1） support reusability of architecturalchanges and 2） enhance the efficiency of the architecture evolution process. We model architecture change logs as a graphand apply graph-based formalism （i.e., graph mining techniques） to discover software architecture change patterns. Wehave developed a prototype that enables tool-driven automation and user decision support during software evolution. Wehave used the IsO-IEC-9126 model to qualitatively evaluate the proposed solution. The evaluation results suggest that theproposed solution 1） enables the reusability of frequent architectural changes and 2） enhances the efficiency of architecture-centric software evolution process. The proposed solution promotes research efforts to exploit the history of architecturalchanges to empirically discover knowledge that can guide architecture-centric software evolution.

关键词： software architecture software maintenance and evolution evolution pattern repository mining

Effect of Groundnut shell Powder on the Mechanical Properties of Recycled Polyethylene and Its biodegradability

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Minerals and Materials Characterization and Engineering 2016年第3期4卷 228-240页

作者： Mohammed Awwalu Usman Ibrahim Momohjimoh Abdulahi s. b. Gimba Department of Chemical Engineering University of Lagos Lagos Nigeria Department of Metallurgical Engineering Yaba College of Technology Lagos Nigeria skilia Resources Ltd. Abuja Nigeria

Natural fiber reinforced composites have gained considerable attention particularly in the manufacturing industry owing to their light weight, corrosion resistance, abundance, and biodegradability. In this work, alkaline treated and untreated groundnut shell powder (GsP) was used to reinforce recycled polyethylene to produce GsP-recycled polyethylene composites with improved mechanical properties and biodegradability. GsP with particle sizes of 0 - 300 μm and 300 - 600 μm was used in different proportions: 5%, 10%, 15%, 20%, 25%, and 30% wt. The fiber was immersed for 5 hours in a 10 wt% NaOH solution. Tensile and hardness test data showed an improvement in mechanical properties of the treated fiber composites. Results of water absorption test also showed that treated GsP-recycled polyethylene composites had a lower rate of water absorption than the untreated GsP-recycled polyethylene composites. Through Fourier transform infrared spectroscopy, disappearance of characteristics peaks of hemicellulose and lignin was observed. Growth of fungi on the fiber-reinforced composites was observed, which was evidence that GsP-recycled polyethylene composite was biodegradable. Finally, sEM micrographs showed uniform distribution of treated fibers in the polymer matrix;this explained the observed improvement in the mechanical properties of treated GsP-recycled polyethylene composites.

关键词： Groundnut shell Powder Fibers Recycled Polyethylene Composites Mechanical Properties biodegradability

Deadwood affects the soil organic matter fractions and enzyme activity of soils in altitude gradient of temperate forests

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Forest Ecosystems 2023年第3期10卷 316-327页

作者： Ewa błońska Wojciech Prazuch Jarosław Lasota Department of Ecology and silviculture Faculty of ForestryUniversity of Agriculture in Krakow29 Listopada 46 Str.31-425KrakowPoland

The main objective of our study has been to determine the role of deadwood in the shaping of the amount of soil organic matter fractions in mountain forest *** this purpose,a climosequence approach comprising north(N)and south(s)exposure along the altitudinal gradient(600,800,1000 and 1200 m a.s.l.)was set *** comparing the properties of decomposing deadwood and those of the soils located directly beneath the decaying wood we drew conclusions about the role of deadwood in the shaping of soil organic matter fractions and soil carbon storage in different climate *** basic properties,enzymatic activity and fractions of soil organic matter(sOM)were determined in deadwood and affected directly by the components released from decaying *** decomposed deadwood impacts soil organic matter stabilization more strongly than the less decayed deadwood and the light fraction of sOM is more sensitive to deadwood effects than the heavy fraction regardless of the location in the altitude *** in sOM mineral-associated fraction C content is more pronounced in soils under the influence of deadwood located in lower locations of warmer *** released from decaying wood stimulate the enzymatic activity of soils that are within the range of deadwood influence.

关键词： Enzyme activity Forest soils Heavy fraction Light fraction soil organic matter

A Two-Temperature supernova Fallback Disk Model for Anomalous X-ray Pulsars

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Astronomy and Astrophysics 2002年第2期2卷 161-168页

作者： YeLu K.s.Cheng NationalAstronomicalObservatories ChineseAcademyofSciencesBeijing100012 DepartmentofPhysics UniversityofHongKongHongKongChina

We present a case study of the relevance of the radially pulsational instability of a two-temperature accretion disk around a neutron star to anomalous X-ray pulsars (AXPs). Our estimates are based on the approximation that such a neutron star disk with mass in the range of 10-6-10-5 M⊙ is formed by supernova fallback. We derive several peculiar properties of the accretion disk instability: a narrow interval of X-ray pulse periods; lower X-ray luminosities; a period derivative and an evolution time scale. All these results are in good agreement with the observations of the AXPs.

关键词： pulsars: general ─pulsars ─stars: neutron ─X-rays: stars─ accretion disk─instability

Parameter Tuned Machine Learning based Emotion Recognition on Arabic Twitter Data

在线全文

学校读者我要写书评

暂无评论

Computer systems science & Engineering 2023年第9期46卷 3423-3438页

作者： Ibrahim M.Alwayle badriyya b.Al-onazi Jaber s.Alzahrani Khaled M.Alalayah Khadija M.Alaidarous Ibrahim Abdulrab Ahmed Mahmoud Othman Abdelwahed Motwakel Department of Computer science College of Science and ArtsSharurahNajran UniversityNajran55461Saudi Arabia Department of Language Preparation Arabic Language Teaching InstitutePrincess Nourah bint Abdulrahman UniversityP.O.Box 84428Riyadh11671Saudi Arabia Department of Industrial Engineering College of Engineering at AlqunfudahUmm Al-Qura UniversityNajran24211Saudi Arabia Computer Department Applied CollegeNajran UniversityNajran66462Saudi Arabia Department of Computer science Faculty of Computers and Information TechnologyFuture University in EgyptNew Cairo11835Egypt Department of Computer and self Development Preparatory Year DeanshipPrince Sattam bin Abdulaziz UniversityAlKharjSaudi Arabia

Arabic is one of the most spoken languages across the ***,there are fewer studies concerning sentiment Analysis(sA)in *** recent years,the detected sentiments and emotions expressed in tweets have received significant *** substantial role played by the Arab region in international politics and the global economy has urged the need to examine the sentiments and emotions in the Arabic *** common models are available:Machine Learning and lexicon-based approaches to address emotion classification *** this motivation,the current research article develops a Teaching and Learning Optimization with Machine Learning based Emotion Recognition and Classification(TLbOML-ERC)model for sentiment Analysis on tweets made in the Arabic *** presented TLbOML-ERC model focuses on recognising emotions and sentiments expressed in Arabic *** attain this,the proposed TLbOMLERC model initially carries out data pre-processing and a Continuous bag Of Words(CbOW)-based word embedding *** addition,Denoising Autoencoder(DAE)model is also exploited to categorise different emotions expressed in Arabic *** improve the efficacy of the DAE model,the Teaching and Learning-based Optimization(TLbO)algorithm is utilized to optimize the *** proposed TLbOML-ERC method was experimentally validated with the help of an Arabic tweets *** obtained results show the promising performance of the proposed TLbOML-ERC model on Arabic emotion classification.

关键词： Arabic language Twitter data machine learning teaching and learning-based optimization sentiment analysis emotion classification

braneworld Inflation with Induced Gravity and Curvature Effect

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2011年第6期55卷 1132-1146页

作者： Kourosh Nozaril s. shafizadeh Department of Physics Science and Research BranchIslamic Azad UniversityMazandaranIran Department of Physics Faculty of Basic SciencesUniversity of MazandaranP.O.Box 47416-95447BabolsarIran

We construct a general braneworld inflation scenario where the inflaton field evolves on the DGP brahe and curvature effects are taken into account via incorporation of the Gauss-bonnet term in the bulk action. While induced gravity on the DGP brane modifies the IR limit of general relativity, the Gauss-bonnet term in the bulk action modifies the UV sector of the theory. In this setup, the dynamics of perturbations on the brane are studied with details and some confrontation with recent observations are discussed. While the Einstein-Gauss-bonnet inflation scenario favors only a red spectrum of the scalar perturbation, pure DGP and GbIG inflation models have the capacity to realize the blue spectrum too. In addition, the GbIG inflation scenario in the large field limit requires a smaller number of e-folds than other proposed scenarios in the same situation. For the tensor-to-scalar ratio, the GbIG inflation scenario g/yes a better fit with observationally supported value of R≈ 0.24.

关键词： inflation cosmological perturbations induced gravity Gauss-bonnet effect

Ensemble Classifier Technique to Predict Gestational Diabetes Mellitus (GDM)

在线全文

学校读者我要写书评

暂无评论

Computer systems science & Engineering 2022年第1期40卷 313-325页

作者： A.sumathi s.Meganathan sRC SASTRA Deemed to be UniversityKumbakonamTamil Nadu612001India

Gestational Diabetes Mellitus(GDM)is an illness that represents a certain degree of glucose intolerance with onset or first recognition during *** the past few decades,numerous investigations were conducted upon early identification of *** Learning(ML)methods are found to be efficient prediction techniques with significant advantage over statistical *** this view,the current research paper presents an ensemble of ML-based GDM prediction and classification *** presented model involves three steps such as preprocessing,classification,and ensemble voting *** first,the input medical data is preprocessed in four levels namely,format conversion,class labeling,replacement of missing values,and ***,four ML models such as Logistic Regression(LR),k-Nearest Neighbor(KNN),support Vector Machine(sVM),and Random Forest(RF)are used for *** addition to the above,RF,LR,KNN and sVM classifiers are integrated to perform the final classification in which a voting classifier is also *** order to investigate the proficiency of the proposed model,the authors conducted extensive set of simulations and the results were examined under distinct ***,the ensemble model has outperformed the classical ML models with a precision of 94%,recall of 94%,accuracy of 94.24%,and F-score of 94%.

关键词： GDM machine learning classification ensemble model

sTUDIEs ON CALCIUMsULPHOALUMINATE DICALCIUM sILICATE CLINKERs

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

STUDIES ON CALCIUMSULPHOALUMINATE DICALCIUM SILICATE CLINKER...

Integrated numerical model for vegetated surface and saturated subsurface flow interaction

第二届北京国际水泥及混凝土学术会议

作者： s. Krishnan R. K. Agarwal b.V.b. Pai P.s. Parameswaran A.K. Chatterjee The Associated Cement Cos. Ltd. Central Research StationThane (India)

REsUME Major phases in the CaO - A12O3, - siO2 - sO3 system, normally formed are C4 A3s. C12 A7, CA, C2s and Cs. Within this system to obtain C4 A3s as the major phase along with C2s, raw mixes were designed and sintered In the temperature range of 1250-1350℃. The clinkers obtained were studied by microscopic and X-Ray differaction techniques. both these studies confirmed the presence of C4 A3s as a major phase with dicalcium silicate (C2s). Properties of cement produced from these clinkers have been studied earlier. The present study involves the effect of uncombined lime in the clinkers at different levels and the influence of gypsum incorporated in the cement during cement grinding on hydraulic behaviour of the resultant cement. The properties of self levelling grouting composition made from such clinker is also reported.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2012年第7期33卷 881-898页

作者： K. s. ERDURAN Department of Civil Engineering Faculty of Engineering University of Nigde Department of Civil Engineering College of Engineering American University of Sharjah

The construction of an integrated numerical model is presented in this paper to deal with the interactions between vegetated surface and saturated subsurface flows. A numerical model is built by integrating the previously developed quasi-three-dimensional （Q3D） vegetated surface flow model with a two-dimensional （2D） saturated groundwater flow model. The vegetated surface flow model is constructed by coupling the explicit finite volume solution of 2D shallow water equations （sWEs） with the implicit finite difference solution of Navier-stokes equations （NsEs） for vertical velocity distribution. The subsurface model is based on the explicit finite volume solution of 2D saturated groundwater flow equations （sGFEs）. The ground and vegetated surface water interaction is achieved by introducing source-sink terms into the continuity equations. Two solutions are tightly coupled in a single code. The integrated model is applied to four test cases, and the results are satisfactory.

关键词： vegetated surface flow saturated groundwater flow flow interaction tightcoupling finite volume method finite difference method flow resistance