检索结果-南通市图书馆

贵州航天 1994年第4期 18-27页

作者： jann,aa 董真

Comparison of adaptive structural damage identification techniques in nonlinear hysteretic vibration isolation systems

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2013年第4期12卷 659-667页

作者： Mu Tengfei Zhou Li jann N.Yang State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and Astronautics Department of Civil and Environmental Engineering University of California

Early structural damage identification to obtain an accurate condition assessment can assist in the reprioritization of structural retrofitting schedules in order to guarantee structural safety. Nowadays, seismic isolation technology has been applied in a wide variety of infrastructure, such as buildings, bridges, etc., and the health conditions of these nonlinear hysteretic vibration isolation systems have received considerable attention. To effectively detect structural damage in vibration isolation systems based on vibration data, three time-domain analysis techniques, referred to as the adaptive extended Kalman filter （AEKF）, adaptive sequential nonlinear least-square estimation （ASNLSE） and adaptive quadratic sum-sqnares error （AQSSE）, have been investigated. In this research, these analysis techniques are compared in terms of accuracy, convergence and efficiency, for structural damage detection using experimental data obtained through a series of laboratory tests based on a base-isolated structural model subjected to E1 Centro and Kobe earthquake excitations. The capability of the AEKF, ASNLSE and AQSSE approaches in tracking structural damage is demonstrated and compared.

关键词： structural health monitoring parameter identification damage tracking nonlinear hysteretic system experimental verification

Leveraging machine learning to generate a unified and complete building height dataset for Germany

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Energy and AI

Energy and AI 2024年第3期17卷 327-341页

作者： Kristina Dabrock Noah Pflugradt jann Michael Weinand Detlef Stolten Forschungszentrum Jülich GmbH Institute of Climate and Energy SystemsJülich Systems Analysis52425 JülichGermany RWTH aachen University Chair for Fuel CellsFaculty of Mechanical Engineering52062 AachenGermany

Building geometry data is crucial for detailed, spatially-explicit analyses of the building stock in energy systems analysis and beyond. Despite the existence of diverse datasets and methods, a standardized and validated approach for creating a nation-wide unified and complete dataset of German building heights is not yet available. This study develops and validates such a methodology, combining different data sources for building footprints and heights and filling gaps in height data using an XGBoost machine learning algorithm. The XGBoost model achieves a mean absolute error of 1.78 m at the national level and between 1.52 m and 3.47 m at the federal state level. The goal is proving the applicability of the methodology at a large scale and creating a useful dataset. The resulting dataset is thoroughly evaluated on a building-by-building level and spatially resolved statistics on the quality of the dataset are reported. This detailed validation found that the building number and footprint area of German building stock is 90.31 % and 94.84 % correct, respectively, and the building height accuracy is 0.59 m at the national level. However, errors are not homogeneous across Germany and further research is needed into the impact of including additional datasets, especially for regions and building types with lower accuracies. This study proves that the chosen methodology is useful for generating a building height dataset and the workflow, with some modifications for regional data availability, can be transferred to other countries. The generated building dataset for Germany constitutes a valuable data basis for the research community in fields such as energy research, urban planning and building decarbonization policy development.

关键词： Machine learning XGBoost Building height Building footprint 3-D building data Geodata Spatial analysis

Opportunities for large language models and discourse in engineering design

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy and AI

Energy and AI 2024年第3期17卷 136-142页

作者： Jan Göpfert jann M.Weinand Patrick Kuckertz Detlef Stolten Institute of Energy and Climate Research–Techno-economic Systems Analysis(IEK-3) Forschungszentrum Jülich GmbHJülich52425Germany Chair for Fuel Cells RWTH Aachen UniversityFaculty of Mechanical EngineeringAachen52062Germany

In recent years, large language models have achieved breakthroughs on a wide range of benchmarks in natural language processing and continue to increase in performance. Recently, the advances of large language models have raised interest outside the natural language processing community and could have a large impact on daily life. In this paper, we pose the question: How will large language models and other foundation models shape the future product development process? We provide the reader with an overview of the subject by summarizing both recent advances in natural language processing and the use of information technology in the engineering design process. We argue that discourse should be regarded as the core of engineering design processes, and therefore should be represented in a digital artifact. On this basis, we describe how foundation models such as large language models could contribute to the design discourse by automating parts thereof that involve creativity and reasoning, and were previously reserved for humans. We describe how simulations, experiments, topology optimizations, and other process steps can be integrated into a machine-actionable, discourse-centric design process. As an example, we present a design discourse on the optimization of wind turbine blades. Finally, we outline the future research that will be necessary for the implementation of the conceptualized framework.

关键词： Product development process Conceptual design Design methodology Design generation Natural language processing Foundation models Multi-modal models

A systematic review of spatial disaggregation methods for climate action planning

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy and AI

Energy and AI 2024年第3期17卷 458-469页

作者： Shruthi Patil Noah Pflugradt jann M.Weinand Detlef Stolten Jürgen Kropp Institute of Energy and Climate Research Techno-economic Systems Analysis(IEK-3)Forschungszentrum JülichWilhelm-Johnen-StraßeJülich52425NRWGermany University of Potsdam Institute for Environmental Science and GeographyKarl-Liebknecht-Str.24-25Potsdam-Golm14476BrandenburgGermany Chair for Fuel Cells RWTH Aachen Universityc/o IEK-3Forschungszentrum JülichJülich52425NRWGermany Potsdam Institute for Climate Impact Research(PIK) Member of the Leibniz AssociationP.O.Box 601203PotsdamD-14412BrandenburgGermany

National-level climate action plans are often formulated broadly. Spatially disaggregating these plans to individual municipalities can offer substantial benefits, such as enabling regional climate action strategies and for assessing the feasibility of national objectives. Numerous spatial disaggregation approaches can be found in the literature. This study reviews and categorizes these. The review is followed by a discussion of the relevant methods for the disaggregation of climate action plans. It is seen that methods employing proxy data, machine learning models, and geostatistical ones are the most relevant methods for the spatial disaggregation of national energy and climate plans. The analysis offers guidance for selecting appropriate methods based on factors such as data availability at the municipal level and the presence of spatial autocorrelation in the *** the urgency of addressing climate change escalates, understanding the spatial aspects of national energy and climate strategies becomes increasingly important. This review will serve as a valuable guide for researchers and practitioners applying spatial disaggregation in this crucial field.

关键词： Spatial downscaling Proxy data Mass-preserving Climate action plans Spatial autocorrelation Machine learning Geostatistical models

Two Processes Comparison by Using Capability Indices Cpm

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

厦门大学学报(自然科学版) 2002年第S1期 188-189页

作者： K S Chen,jann-Pygn Chen,T W Chen Department of Industrial Engineering & Management National Chin -Yi Institute of Technology Department of Industrial Engineering & Management National Chin -Yi Institute of Technology Department of Mechanical Engineering National Chin-Yi Institute of Technology Taiwan China

In recent years, there has been mounting interest i n measuring process performance in manufacturing industry. Based on analyzing the process capability indices, a production department can trace and improve a poor process to enhance quality levels and satisfy customers. The process capabilit y analysis can also serve as an important reference for making decisions for imp roving the global quality of all products. Since C p and C pk are failed to account for process centering, the index C pm is developed. The index C pm takes the process centering into consideration and is su itable for the processes with nominal-the-best type. There are other indices l ike C pu and C pl, and those indices are used for unilateral s pecification processes. Chou (1994) developed a procedure using estimators of C p, C pu and C pl for practitioners to determine whether two p rocesses are equal capability or not. For bilateral specifications processes, i ndex C p is failed to measure process yield and process centering. Thus, th e index C pm is used to develop a similar procedure for practitioners t o determine whether two processes are equal capability or not. The decisions mad e using the procedure to select the better supplier are, of course, more reliabl e.

关键词： process capability indices test statistic proce ss yield process centering

Two Processes Comparison by Using Capability Indices C_(pm)

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

厦门大学学报（自然科学版） 2002年第S1期41卷 188-189页

作者： K S Chen jann-Pygn Chen T W Chen Department of Industrial Engineering & Management National Chin -Yi Institute of TechnologyDepartment of Industrial Engineering & ManagementNational Chin -Yi Institute of TechnologyDepartment of Mechanical Engineering National Chin-Yi Institute of Technology Taiwan China

关键词： process capability indices test statistic proce ss yield process centering

Thermoelectric transport enhancement of Te-rich bismuth antimony telluride(Bi_(0.5)Sb_(1.5)Te_(3+x))through controlled porosity

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 Materiomics 2020年第3期6卷 532-544页

作者： Ian T.Witting jann A.Grovogui Vinayak P.Dravid G.Jeffrey Snyder Department of Materials Science and Engineering Northwestern University2220 Campus DriveCook Hall 2036EvanstonIL60208USA

Alloys of Bi_(2)Te_(3) and Sb_(2)Te_(3) are the best performing p-type thermoelectrics near room temperature and have been the subject of extensive engineering *** improvement is achieved by introducing defects that effectively scatter phonons and reduce thermal ***,outstanding results are often difficult to reproduce as the process variables involved are difficult to control or possibly ***,a reproducible and controllable method of fabricating porous Bi_(0.5)Sb_(1.5)Te_(3+x) is *** effective medium theory(EMT)predicts no benefit,improvements in the thermoelectric quality factor,B(which determines the maximum zT of a materials),were as high as 45% parallel to the pressing direction for a sample of roughly 20% *** study of microstructural evolution with increasing porosity is facilitated by a combination of Scanning/Transmission Electron Microscopy(S/TEM)and Electron Backscattered Diffraction(EBSD).This study reveals a statistically significant shift in the distribution of grain boundaries favoring lower energy twins,which coincides with an increase in the presence of stepped twin *** work demonstrates the potential benefits of careful grain boundary engineering and the need for further detailed studies of the dependence of thermal and electrical transport on grain boundary structure and orientation in these alloys.

关键词： Bismuth antimony telluride Thermoelectric Porosity Transport modeling Foaming

Pattern of intestinal helminth infections among school children in an urban community in Ibadan,Nigeria

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Medicine 2008年第3期1卷 42-47页

作者： Fatiregun aa Oluwatoba OA Department of Epidemiology Medical Statistics and Environmental HealthFaculty of Public HealthCollege of MedicineUniversity of IbadanIbadanNigeria

Despite a substantial reduction in the incidence and prevalence of parasitic diseases in the industrialized world, they continue to be an important public health problem in many developing African countries,including Nigeria. However,estimates of the prevalence of such infections among school age children,who bear the greatest health burden due to these diseases,are hard to come *** objective of this study was therefore to determine the prevalence and type of intestinal helminth infections among primary school *** study was cross-sectional in *** participants included 266 pupils recruited from three government primary schools in the Mokola area of Ibadan,*** pupils were interviewed and their stool samples examined for eggs of common *** mean age of the pupils was 9.8±2.6 years,and 128(48.1%) were *** pupils(7.1%) had intestinal helminth *** lumbricoides was found in 17 pupils(6. 4%) and was the most prevalent helminth among the children,while Trichuris trichiura was found in only two subjects(0.8%).Previous infestations and the use of public toilets were found to be significantly associated with current infections(P<0.05).This study demonstrated that the prevalence of intestinal infections was low among the pupils studied,and that Ascaris infection was the commonest infestation.

关键词： prevalence intestinal helminths school children

Crystallodiagnostics of some animals' helmintosis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Medicine 2010年第3期3卷 176-179页

作者： Andrew Martusevich Grishina aa Bochkareva AV Laboratory of Physical and Chemical Medicine Institute of Traumatology and Orthopedics

Objective:To investigate the teziocrystalloscopic features of urine which were collected from both healthy rodents and those with ***:Physical-chemical characteristics of urine samples that were collected from 15 mice and 20 rats were estimated by their ability to *** test results were interpreted with integrated identity table which includes 5 main classes of the crystalline and amorphous *** quantitative and semiquantitative evaluation indicators were also ***:Presence of Trichinella spiralis in animal organism transformed results of the biofluid free *** main components of rats’ urine facia were single-crystalline rectangles which were made of cholesterol and its *** biofluid microsamples of healthy rats and rats with echinococcosis had both common and ***:Urine teziocrystalloscopic analysis is an informative method for diagnosis of helminthiasis in animals.

关键词： Biocrystallomics Trichinosis Echinococcosis Crystallodiagnostics Urine