检索结果-内蒙古大学图书馆

ISI BILIMI VE TEKNIGI DERGISI-JOURNAL OF THERMAL SCIENCE AND TECHNOLOGY 2017年第1期37卷 127-137页

作者： Aral, Mumin Celil Hosoz, Murat Subermanto, Mukhamad Kocaeli Univ Dept Automot Engn TR-41380 Izmit Kocaeli Turkey

A laboratory automotive air conditioning (AAC) system was set up and tested for the cases of employing refrigerants R134a and R1234yf. Two different empirical correlations were developed to predict the steady state performance parameters of the AAC system based on some experimental data. The air stream temperatures entering the evaporator and condenser and the relative humidity of the air stream at the evaporator inlet were selected as the input parameters of the proposed correlations, while the output parameters were the cooling capacity, power absorbed by the refrigerant in the compressor, condenser heat rejection rate, coefficient of performance, conditioned air temperature, compressor discharge temperature and the rate of total exergy destruction in the AAC system. Then, the predictions of these correlations were compared with the experimental results which were not used in developing the correlations. The findings suggest that both correlations can be used for accurately predicting the performance parameters of the AAC systems.

关键词： Automotive Air conditioning R1234yf R134a Performance empirical

来源：评论

学校读者我要写书评

暂无评论

empirical interatomic potentials optimized for phonon properties

引用

npj Computational Materials 2017年第1期3卷 227-233页

作者： Andrew Rohskopf Hamid R.Seyf Kiarash Gordiz Terumasa Tadano Asegun Henry George W.Woodruff School of Mechanical Engineering Georgia Institute of TechnologyAtlantaGA 30332USA Center for Materials Research by Information Integration National Institute for Materials ScienceTsukuba 305-0047Japan School of Materials Science and Engineering Georgia Institute of TechnologyAtlantaGA 30332USA Heat Lab Georgia Institute of TechnologyAtlantaGA 30332USA

Molecular dynamics simulations have been extensively used to study phonons and gain insight,but direct comparisons to experimental data are often difficult,due to a lack of accurate empirical interatomic potentials for different *** a result,this issue has become a major barrier to realizing the promise associated with advanced atomistic-level modeling ***,we present a general method for specifically optimizing empirical interatomic potentials from ab initio inputs for the study of phonon transport properties,thereby resulting in phonon optimized *** method uses a genetic algorithm to directly fit the empirical parameters of the potential to the key properties that determine whether or not the atomic level dynamics and most notably the phonon transport are described properly.

关键词： phonon empirical thereby

来源：评论

学校读者我要写书评

暂无评论

Frequent patterns in ETL workflows: An empirical approach

引用

DATA & KNOWLEDGE ENGINEERING 2017年 112卷 1-16页

作者： Theodorou, Vasileios Abello, Alberto Thiele, Maik Lehner, Wolfgang Univ Politecn Cataluna Barcelona Spain Tech Univ Dresden Dresden Germany

The complexity of Business Intelligence activities has driven the proposal of several approaches for the effective modeling of Extract-Transform-Load (ETL) processes, based on the conceptual abstraction of their operations. Apart from fostering automation and maintainability, such modeling also provides the building blocks to identify and represent frequently recurring patterns. Despite some existing work on classifying ETL components and functionality archetypes, the issue of systematically mining such patterns and their connection to quality attributes such as performance has not yet been addressed. In this work, we propose a methodology for the identification of ETL structural patterns. We logically model the ETL workflows using labeled graphs and employ graph algorithms to identify candidate patterns and to recognize them on different workflows. We showcase our approach through a use case that is applied on implemented ETL processes from the TPC-DI specification and we present mined ETL patterns. Decomposing ETL processes to identified patterns, our approach provides a stepping stone for the automatic translation of ETL logical models to their conceptual representation and to generate fine-grained cost models at the granularity level of patterns.

关键词： ETL Patterns empirical Graph matching

来源：评论

学校读者我要写书评

暂无评论

Exploring the feasibility of empirical, dynamical and combined probabilistic rainy season onset forecasts for Sao Paulo, Brazil

引用

INTERNATIONAL JOURNAL OF CLIMATOLOGY 2017年第Sup1期37卷 398-411页

作者： Coelho, Caio A. S. Firpo, Mari A. F. Maia, Aline H. N. MacLachlan, Craig Inst Nacl Pesquisas Espaciais Ctr Previsao Tempo & Estudos Climat Rodovia Presidente Dutra KM 40 BR-12630000 Cachoeira Paulista SP Brazil Empresa Brasileira Pesquisa Agr EMBRAPA Meio Ambi Lab Geotecnol & Metodos Quantitat Jaguariana SP Brazil Met Off Hadley Ctr Exeter Devon England

This study investigates the feasibility and presents an assessment of probabilistic rainy season onset forecasts for Sao Paulo, Brazil, located in a region with a well-defined wet season from mid-austral spring (October) to austral autumn (March/April). The probabilistic forecasts were produced with (1) a simple empirical Cox-regression model using July Nino-3 index as predictor, (2) the dynamical coupled atmosphere-land-surface-ocean-sea-ice model used in the UK Met Office Global Seasonal Forecast System (GloSea5) and (3) a procedure that combines the empirical and dynamical model onset probabilistic forecasts. The probabilistic forecast assessment was performed over the 1996-2009 retrospective forecast period for the event rainy season onset earlier (or later) than the historical (mean) onset date. The three investigated approaches resulted in similar discrimination ability of around 80%, which represents the probability of the probabilistic forecasts correctly distinguishing earlier from a later than mean onsets, suggesting good potential for rainy season onset forecasts for Sao Paulo. The robustness of this assessment for an extended period (longer than 1996-2009) and for a region (20 degrees S, 25 degrees S, 45 degrees W, 55 degrees W) that includes the city of Sao Paulo was checked, reinforcing the validity of the obtained results at both local and regional scales.

关键词： rainy season onset probabilistic forecasts empirical dynamical and combined forecasts

来源：评论

学校读者我要写书评

暂无评论

Design Index and empirical Analysis of the Evaluation Index System for the Transformation of Scientific and Technological Achievements of Universities in Beijing, Tianjin and Hebei

引用

Journal of Educational Theory and Management 2018年第3期2卷 70-75页

作者： Guoru Yang Yuenan Xu School of Public Administration Hebei University of Economics and Business Shijiazhuang Hebei 050061 China

Promoting the transformation of scientific and technological achievements of universities and colleges in Beijing, Tianjin, and Hebei is an important measure to enhance the level of scientific and technological development in universities, enhance the scientific and technological synergy of Beijing-Tianjiii-Hebei urban agglomeration, practice the coordinated development strategy of Beijing, Tianjin and Hebei, and promote the construction of Xiong'an New District. Based on the scientific and technological input of colleges and universities, the development of science and technology and the output of science and technology, this paper uses Delphi and AHP to construct a Beijing, Tianjin, Hebei University Science and Technology Achievement Transformation Performance Evaluation System from the perspectives of transformation potentials, scientific research activities and achievements transformation of university scientific and technological achievements. An empirical analysis was carried out to provide reference for the government's efficient decision-making and improvement of strategies for transforming scientific and technological achievements in universities.

关键词： collaborative development transformation of scientific and technological achievements in universities performance evaluation empirical analysis

来源：评论

学校读者我要写书评

暂无评论

Development of empirical Wind Vulnerability Curves of School Buildings Damaged by the 2016 Typhoon Nina

引用

Procedia Engineering 2018年 212卷 395-402页

作者： T.J.S. Acosta J.J. Galisim L.R. Tan J.Y. Hernandez Institute of Civil Engineering University of the Philippines Diliman Quezon City 0860 Philippines

Last 2016, Typhoon Nina with the international name NOCK-TEN made landfall over Lubang Island. Damage to both infrastructure and agriculture reached ₱6.2 billion as reported by the National Disaster Risk Reduction and Management Council (NDRRMC). Among the infrastructure, an estimated damage of ₱1.1 billion was attributed to the education sector. Damage to non-structural components such as furniture, learning materials, and computer units were estimated to reach at least ₱34.8 million. Aside from functioning as educational facilities, school buildings also serve as evacuation shelters for post disaster recovery operations. Hence strengthening of these structures are of high importance. The Department of Education Bicol Region reported that around 625 schools were totally damaged, 1,082 schools were partially damaged and needed major repairs, and 988 schools needed minor repairs. Most of the damage were observed at the roof coverings, roof frames, wall openings and the walls. Hence these comprise the building components where the damage will be quantified. Field surveys were conducted through region IV and V of the southern part of Luzon, Philippines. From the field survey, damage of every building component are quantified as the percentage of damaged elements to the total number of units of the corresponding building component comprising one building. Each percent damage to building component is converted to an equivalent ratio of the repair cost to the total building construction cost, defined as the damage ratio. Each damage ratio is plotted against the corresponding maximum local wind speed, forming the empirical vulnerability curves. The wind speed data was retrieved from an open source wind speed data map provided by Professor Mark Saunders from the University College of London. Vulnerability curves were curve-fitted using a cumulative lognormal distribution for wind speeds ranging from 96 – 242kph (26 – 68mps). Results can then be used by the local government

关键词： 2016 Typhoon Nina field survey building damage school buildings resilience empirical vulnerability curves wind

来源：评论

学校读者我要写书评

暂无评论

When do agents outperform centralized algorithms? A systematic empirical evaluation in logistics

引用

AUTONOMOUS AGENTS AND MULTI-AGENT SYSTEMS 2017年第6期31卷 1578-1609页

作者： van Lon, Rinde R. S. Holvoet, Tom Katholieke Univ Leuven Imec DistriNet B-3001 Leuven Belgium

Multi-agent systems (MAS) literature often assumes decentralized MAS to be especially suited for dynamic and large scale problems. In operational research, however, the prevailing paradigm is the use of centralized algorithms. Present paper empirically evaluates whether a multi-agent system can outperform a centralized algorithm in dynamic and large scale logistics problems. This evaluation is novel in three aspects: (1) to ensure fairness both implementations are subject to the same constraints with respect to hardware resources and software limitations, (2) the implementations are systematically evaluated with varying problem properties, and (3) all code is open source, facilitating reproduction and extension of the experiments. Existing work lacks a systematic evaluation of centralized versus decentralized paradigms due to the absence of a real-time logistics simulator with support for both paradigms and a dataset of problem instances with varying properties. We extended an existing logistics simulator to be able to perform real-time experiments and we use a recent dataset of dynamic pickup-and-delivery problem with time windows instances with varying levels of dynamism, urgency, and scale. The OptaPlanner constraint satisfaction solver is used in a centralized way to compute a global schedule and used as part of a decentralized MAS based on the dynamic contract-net protocol (DynCNET) algorithm. The experiments show that the DynCNET MAS finds solutions with a relatively lower operating cost when a problem has all following three properties: medium to high dynamism, high urgency, and medium to large scale. In these circumstances, the centralized algorithm finds solutions with an average cost of 112.3% of the solutions found by the MAS. However, averaged over all scenario types, the average cost of the centralized algorithm is 94.2%. The results indicate that the MAS performs best on very urgent problems that are medium to large scale.

关键词： Multi-agent systems Agents Centralized Decentralized empirical Evaluation Dynamism Urgency Scale Operational research Logistics

来源：评论

学校读者我要写书评

暂无评论

Assessment of Rock Mass Quality and Deformation Modulus by empirical Methods along Kandiah River, KPK, Pakistan

引用

Open Journal of Geology 2018年第10期8卷 947-964页

作者： Mian Sohail Akram Kamran Mirza Muhammad Zeeshan Muhammad Asad Jabbar Institute of Geology University of the Punjab Lahore Pakistan

The pivotal aim of this study is to evaluate the rock mass characterization and deformation modulus. It is vital for rock mass classification to investigate important parameters of discontinuities. Therefore, Rock Mass Rating (RMR) and Tunneling quality index (Q) classification systems are applied to analyze 22 segments along proposed tunnel routes for hydropower in Kandiah valley, Khyber Pakhtunkhwa, Pakistan. RMR revealed the range of fair to good quality rocks, whereas Q yielded poor to fair quality rocks for investigated segments of the rock mass. Besides, Em values were acquired by empirical equations and computer-aided program RocLab, and both methods presented almost similar variation trend of their results. Hence, the correlations of Em with Q and RMR were carried out with higher values of the regression coefficient. This study has scientific significance to initially understand the rock mass conditions of Kandiah valley.

关键词： Rock Mass Classification RMR and Q Deformation Modulus (Em) empirical Equations RocLab Tunnel

来源：评论

学校读者我要写书评

暂无评论

Practice Wisdom Knowledge Versus empirical Science Knowledge:Guiding Historical Social Work Direct Practice

引用

Sociology Study 2018年第7期8卷 305-312页

作者： Randall Basham University of Texas at Arlington USA

For social workers who are interested in research associated with validating methodology for the amelioration of human problems,or the mastery of intervention models,used in direct practice;definitive consensus,on guidelines,remains *** has been written in recent years about the necessity of the profession to be guided by either empirical research,which has validated specific interventions,or by the theory,heuristic rules,and the decision‐making schema of experienced *** debate is not simply limited to clinical practice issues,or factions defending or refuting,a particular theoretical *** one hand,social research has in recent years,invalidated some long held practice models,and has modified our understanding of core social ***,social research is an often difficult and arduous pursuit,which may require some time to make thorough evaluation,as compared to the immediacy of emerging social *** transmission of scholarly research findings takes time and considerable effort to disseminate and gain understanding and acceptance within the practice community even when well *** the other hand,practitioners serve as the wellspring of observations,which are often translated into models or theory,and frequently become the subject matter of empirical ***,few in the practice community are encouraged or committed,to systematically review research findings so as to modify practice approaches,which have not been well validated by recent research findings.

关键词： Social work practice wisdom empirical science evidence based practice

来源：评论

学校读者我要写书评

暂无评论

Maximum Entropy empirical Likelihood Methods Based on Bivariate Laplace Transforms and Moment Generating Functions

引用

Open Journal of Statistics 2018年第2期8卷 264-283页

作者： Andrew Luong école d’Actuariat Université Laval Québec Canada

Maximum Entropy empirical Likelihood (MEEL) methods are extended to bivariate distributions with closed form expressions for their bivariate Laplace transforms (BLT) or moment generating functions (BMGF) without closed form expressions for their bivariate density functions which make the implementation of the likelihood methods difficult. These distributions are often encountered in joint modeling in actuarial science and finance. Moment conditions to implement MEEL methods are given and a bivariate Laplace transform power mixture (BLTPM) is also introduced, the new operator generalizes the existing univariate one in the literature. Many new bivariate distributions including infinitely divisible(ID) distributions with closed form expressions for their BLT can be created using this operator and MEEL methods can also be applied to these bivariate distributions.

关键词： Bivariate Power Mixture Operator Laplace Transform Copulas Chi-Square Test Statistics Bivariate Normality Infinite Divisibility empirical Likelihood

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：