检索结果-内蒙古大学图书馆

Sound absorption estimation using the discrete complex image source method and array processing

MECHANICAL SYSTEMS AND SIGNAL PROCESSING 2025年 231卷

作者： Brandao, Eric Fonseca, William D'Andrea Mareze, Paulo Henrique Resende, Carlos Azzuz, Gabriel Pontalti, Joao Fernandez-Grande, Efren Fed Univ Santa Maria UFSM Acoust Engn Program BR-97105900 Santa Maria RS Brazil Fed Univ Santa Maria UFSM Grad Program Civil Engn BR-97105900 Santa Maria RS Brazil Fed Univ Santa Maria UFSM Grad Program Architecture Urbanism & Landscaping BR-97105900 Santa Maria RS Brazil Fed Univ Santa Maria UFSM Grad Program Mech Engn BR-97105900 Santa Maria RS Brazil Univ Politecn Madrid UPM Dept Ingn Audiovisual Madrid 28040 Spain

Estimating the sound absorption of a material under realistic sound-field incidence conditions relies on accurately describing the measured data. Evidence suggests that modeling the reflection of impinging spherical waves is important, especially for compact measurement systems. This article proposes a method for estimating the sound absorption coefficient of a material sample by mapping the sound pressure, measured by a microphone array, to a distribution of monopoles, including the sound source and a series of complex image-sources. The proposed method is compared to modeling the sound field as a superposition of two sources (a monopole and an image source). The sound absorption measurement is tested with simulations of the sound field above infinite and non-locally reacting porous absorbers. The inverse problem estimations are compared to the classical plane-wave absorption coefficient and the one obtained by measuring the surface impedance when a spherical wave impinges on the absorber. Experimental analysis of two porous samples and one resonant absorber is also carried out in a laboratory. Two microphone arrays were tested with different apertures and number of sensors, and it was demonstrated that measurements are feasible even with the more compact array and for frequencies above 250 [Hz]. The discretization of the integral equation led to a more accurate reconstruction of the sound pressure and particle velocity at the sample's surface. The resulting absorption coefficient agrees with the one obtained for spherical wave incidence, indicating that including the source and several complex image-sources is an essential feature of the sound field.

关键词： Discrete complex image sources Absorption coefficient Microphone array

来源：评论

学校读者我要写书评

暂无评论

Effects on Physicochemical and Microbiological Properties of Coconut Water Packaged in Silver-Based Materials

引用

PACKAGING TECHNOLOGY AND SCIENCE 2025年第5期38卷 393-406页

作者： Malafatti, Joao Otavio Donizette Brito, Sabrina da Costa Pereira, Vinicius Alex Cano Calisto, Italo Netto, Saad Barbar Formigoni, Carlos Eduardo Innocentini, Murilo Daniel de Mello Mitsuyuki, Milene Corso Sivieri, Katia Ferreira, Marcos David Embrapa Instrumentacao Sao Carlos SP Brazil Sao Paulo State Univ Julio Mesquita Filho Postgrad Program Food Sci & Engn Araraquara SP Brazil Univ Fed Sao Carlos Biotechnol Grad Program Sao Carlos SP Brazil Univ Sao Paulo Chem Grad Program Sao Carlos SP Brazil Univ Ribeirao Preto Postgrad Program Environm Technol Ribeirao Preto SP Brazil Univ Bath Ctr Regenerat Design & Engn Net Posit World RENEW Dept Architecture & Civil Engn Bath England

Coconut water is a fresh and popular drink that is attractive to consumers worldwide. Packaging development is essential to improve product quality, protect against microorganism contamination and preserve their physical-chemistry properties. Silver nanoparticles (AgNPs) are excellent actives applied in studies of food packaging, exhibiting great antimicrobial activity and reinforcement properties in polymeric matrices. The current work goals are to evaluate AgNPs supported on carriers, silica (SiO2) and hydroxyapatite (Hap) in the linear low-density polyethylene (LLDPE) polymer obtained nanocomposite materials (LLDPE/AgNPs) to coconut water packaging. Thus, the present assay ascertained if adding these active agents in a commercial material (LLDPE) may improve coconut water's physicochemical and microbiological characteristics. The processing obtained the packaging composites at two concentrations (0.4% and 0.6%) by extrusion methodology. The pasteurized coconut water was packaged and monitored during 35 days of storage at temperatures above the recommended (7 degrees C). The physicochemical analyses of coconut water verified the maintenance of pH, titratable acidity, soluble solids content, colour, turbidity, phenolic compounds, antioxidant activities, reducing and nonreducing sugars and minerals. Microbiological analyses were performed to detect the growth of psychrotrophic, moulds and yeasts, enterobacteria and Salmonella spp. The results showed that the AgNPs supported in both particles did not affect coconut water's physical and chemical characteristics compared to the LLDPE control. Concerning microbial growth, adding particles reduced the product's microbial load. Thus, the LLDPE/AgNPs packages obtained in this work demonstrated a potential application as commercial material to coconut water that can preserve the intrinsic physicochemical and improve the microbiological quality.

关键词： antimicrobial coconut water food packaging nanocomposite silver nanoparticles

来源：评论

学校读者我要写书评

暂无评论

Approaching accessibility: Four opportunities to address the needs of disabled people in transportation planning in the United States

引用

TRANSPORT POLICY 2023年 131卷 66-74页

作者： Levine, Kaylyn Karner, Alex Univ Texas Austin Sch Architecture Grad Program Community & Reg Planning 310 Inner Campus Dr B7500 Austin TX 78712 USA

In common transportation planning practice and research, disability is largely mistreated and oversimplified. This review essay identifies four shortcomings in U.S. transportation planning that perpetuate oversight, exclusion, and inadequate transportation systems for disabled people. Compliance-based agendas are used by public agencies to implement accessibility accommodations based on minimum requirements, failing to consider the everyday experiences of disabled people. Data gaps and access to opportunity assumptions reveal how transportation planning and analysis approaches are inadequate when considering the disability community. Lastly, the narrow focus on mobility disability in the transportation field ignores the diversity of human conditions. These existing challenges are defined in detail with examples of how disability justice ideas and inclusive public engagement practices can address each shortcoming. Meaningful public engagement with the disability community would improve how transportation planning, policy, and practice address the needs and lived experiences of this critical population group.

关键词： Disability Accessibility Public engagement

来源：评论

学校读者我要写书评

暂无评论

Use of bacterial binder in repair mortar for micro-crack remediation

引用

APPLIED MICROBIOLOGY AND BIOTECHNOLOGY 2023年第9期107卷 3113-3127页

作者： Ciplak, Elif Sirt Bilecen, Kivanc Akoglu, Kiraz Goze Guchan, Neriman Sahin METU Fac Architecture Grad Program Conservat Cultural Heritage TR-06800 Ankara Turkiye Konya Food & Agr Univ Dept Mol Biol & Genet TR-42080 Konya Turkiye

Micro-cracks are one of the types of stone deterioration which can propagate and lead to surface detachments and larger cracks in the long run. The present study developed a sustainable and environmentally friendly infill material-biological mortar (BM), as an alternative to conventional approaches. Using a biomineralization approach, this BM was explicitly designed for healing micro-cracks (less than 2 mm) in historic travertines. To this end, the mortar was prepared using a calcifying Bacillus sp. isolated from thermal spring water resources in Pamukkale Travertines (Denizli), stone powder gathered from travertine quarries in the vicinity, and a triggering solution specifically designed to set off calcium carbonate precipitation reaction. After setup, BM was applied to micro-cracks of artificially aged test stones for testing. Scanning electron microscopy revealed calcium carbonate-coated Bacillus sp. bodies in the BM matrix, optical microscopy showed secondary calcite minerals throughout the BM applied micro-cracks, and stereomicroscopy and nanoindentation analyses demonstrated bonding of BM with stone due to microbial calcification activities. Furthermore, BM and original material contact showed a continuous and coherent structure in all samples. Within this context, BM could be considered a promising and alternative approach for the remediation of micro-cracks of historic stones.

关键词： Calcite Bacteria Micro-crack Biological mortar Conservation Travertine

来源：评论

学校读者我要写书评

暂无评论

Comparing tree structures derived among airborne, terrestrial and mobile LiDAR systems in urban parks

引用

GISCIENCE & REMOTE SENSING 2022年第1期59卷 843-860页

作者： Choi, Heejoon Song, Youngkeun Seoul Natl Univ Interdisciplinary Program Landscape Architecture Seoul South Korea Seoul Natl Univ Grad Sch Environm Studies Dept Landscape Architecture Seoul South Korea

Measuring tree structure using three-dimensional (3D) mapping tools such as light detection and ranging (LiDAR) remote sensing is needed to provide well-managed and designed green spaces. The metrics used to estimate tree structure could be different depending on which LiDAR systems are used. This may lead to confusion and reduce confidence when evaluating tree structures and their derived products, such as plant area index (PAI). Therefore, studies that can determine similarities among measurements derived from different LiDAR systems are needed. In this study, structural canopy metrics in airborne laser scanning (ALS), terrestrial laser scanning (TLS), and mobile laser scanning (MLS) were compared to seek consistencies among the three LiDAR systems. The specific objectives were to test whether the estimates made by the metrics differed depending on single or clustered trees and to test whether LiDAR-derived errors in the metrics are related to tree structures. Tree point clouds were manually classified into single and clustered trees. Heights-related metrics, Rumple Index, area, and PAI were calculated for comparison analysis. Root-mean-square error (RMSE), bias, and Pearson's correlation coefficient (r) were calculated to evaluate the consistencies in each metric among the LiDAR systems. The results showed that the maximum height of the point clouds (ZMAX) and max and mean heights derived from the canopy height models (minCHM and maxCHM) demonstrated good consistency (RMSE% < 10%, Bias% < 10%, and r > 0.900). Moreover, the biases from the ZMAX- and CHM-derived metrics comparisons among the LiDAR systems did not show strong linear relationships with the tree heights and canopy complexities (i.e. Pearson's correlation coefficient r < |0.29|). On the contrary, the 95th percentile (Zq95) height and mean z height (ZMEAN) differed depending on the tree classes and showed significant linear relations with canopy heights and complexity. The configurations of LiDAR system

关键词： Airborne laser scanning terrestrial laser scanning mobile laser scanning canopy structure SLAM

来源：评论

学校读者我要写书评

暂无评论

Real-Time Face Mask Detection with Deep Learning for Pandemic Safety 17

Real-Time Face Mask Detection with Deep Learning for Pandemi...

引用

17th International Conference on Signal-Image Technology and Internet-Based Systems, SITIS 2023

作者： Sudthongkhong, Chudanat Intarapasan, Budsakayt Wongsheree, Thitima Thanasuan, Kejkaew Pattanapipat, Bennapa Suksai, Putawan School of Architecture and Design Department of Medical and Science Media Bangkok Thailand Interior Architecture Program School of Architecture and Design Bangkok Thailand Bangkok Thailand School of Architecture and Design Department of Media Technology Bangkok Thailand The Faculty of Mass Communication Technology Bangkok Thailand

ISBN: (纸本)9798350370911

Amid the COVID-19 pandemic, efficient screening of individuals has become imperative. Our project aims to develop an automated system that combines Computer Vision, Infrared Thermometer sensors, and Data Analytics to streamline This process while ensuring public safety. Our objectives encompass designing and implementing an automated screening system, improving data handling and storage, and rigorously testing system efficiency. This system surpasses traditional temperature gauges with a remarkable 93.67% accuracy and excels in detecting sanitary mask compliance with a rate of 96.78%. Additionally, it contributes to environmental sustainability by completely eliminating outdoor waste generation. The user-friendly interface and systematic data storage in a database enable retrospective analysis and efficient data management. Expert assessments and performance tests ensure the system's quality and practicality. In summary, our project introduces an automated system that enhances user screening during the COVID-19 outbreak, offering high accuracy, efficiency, and data management capabilities. This system plays a crucial role in safeguarding public health and community well-being. In the future research, the accuracy results comparison between this method and other methods will be report in the next conference. © 2023 IEEE.

关键词： COVID-19

来源：评论

学校读者我要写书评

暂无评论

Confirmatory Factor Analysis of Service Quality of Thai Small-Medium Enterprise Contractors in Construction Projects 7

Confirmatory Factor Analysis of Service Quality of Thai Smal...

引用

7th International Conference on E-Business and Internet, ICEBI 2023

作者： Ngowtanasuwan, Grit Construction Management Program Faculty of Architecture Urban Design and Creative Arts Mahasarakham University 44150 Thailand

ISBN: (纸本)9798400716508

The service quality of small and medium enterprise (SME) contractors in Thailand was assessed using confirming factor analysis (CFA) to study related factors and variables from the literature and expert opinions. The sample group consisted of 264 project owners in the northeastern region of Thailand comprising Roi Et, Khon Kaen, Maha Sarakham and Kalasin Provinces. Results determined three service quality factors of Thai SME contractors as (1) empathy, (2) responsive-ness, and (3) tangibles. The empathy factor of tidiness after work was the most important, followed by providing maintenance services for work completed. The responsiveness factor consisted of behaviors of the workers instill confidence in the project owner as the most important, followed by willingness to help the project owner include additional work. The tangibles factor included details of documents as the most important, followed by sufficient manpower to complete as-signed work and proper material storage and good housekeeping. Guidelines for strategies to improve the service quality of Thai SME contractors are presented in the conclusions of this research paper. © 2023 Copyright held by the owner/author(s).

关键词： Contractors

来源：评论

学校读者我要写书评

暂无评论

Sectoral priorities in the modernisation of engineering education in Brazil

引用

EUROPEAN JOURNAL OF ENGINEERING EDUCATION 2024年第6期49卷 1288-1309页

作者： Barcellos, Demian S. Abade, Victor A. B. Chrusciak, Camilla B. Machado, Juliana T. Dias, Izamara C. P. Mello, Graziella M. V. Luna Romero, Santiago F. Amos, Jennifer R. Diogo, Ricardo A. Pontificia Univ Catolica Parana Urban Management Grad Program Curitiba Brazil Pontificia Univ Catolica Parana Architecture & Urbanism Undergrad Program Curitiba Brazil Vrije Univ Brussel Fac Law & Criminol Dept Criminol Brussels Belgium Pontificia Univ Catolica Parana Ind & Syst Engn Grad Program Curitiba Brazil Pontificia Univ Catolica Parana Hlth Sci Grad Program Curitiba Brazil Pontificia Univ Catolica Parana Hlth Technol Grad Program Curitiba Brazil Univ Illinois Dept Bioengn Champaign IL USA Pontificia Univ Catolica Parana Mechatron Engn Undergrad Program Curitiba Brazil

Modernising engineering education demands integrating diverse perspectives through multidisciplinary, collaborative approaches. In developing countries, collaboration with stakeholders presents a significant challenge. This study aimed to develop a novel collective approach to establish priorities for modernising engineering education. A workshop was conducted by the Modernisation of Undergraduate Education program at the Pontifical Catholic University of Paran & aacute;in a Southern Brazilian metropolis, with 63 stakeholders from various sectors (education, experts, government, industry, and civil society organisations). The workshop consisted of three rounds discussions, including two rounds with stakeholders of the same sector and one round with stakeholders of different sectors mixed in discussion tables. Each table, comprising 3-7 participants, aimed to reach a consensus. Several topics were addressed in the discussions, including curricularization of extension, updating outdated curricular bases, and integrating soft skills and entrepreneurship into engineering programs. The resulting goals emphasised the integration of engineering education with society and industry. Participants agreed on short to medium-term deadlines for achieving these goals. This approach connected stakeholders, fostering an extensive collaborative, multisectoral network supporting engineering education modernisation.

关键词： Stakeholder engagement multidisciplinary prioritisation process industry engineering education

来源：评论

学校读者我要写书评

暂无评论

Integrity with Extraction Faults in LiDAR-Based Urban Navigation for Driverless Vehicles

Integrity with Extraction Faults in LiDAR-Based Urban Naviga...

引用

IEEE/ION Position, Location and Navigation Symposium (PLANS)

作者： Nagai, Kana Chen, Yihe Spenko, Matthew Henderson, Ron Pervan, Boris IIT Mech & Aerosp Engn Chicago IL 60616 USA IIT Landscape Architecture Urbanism Program Chicago IL USA

ISBN: (纸本)9781665417723

This paper examines the safety of LiDAR-based navigation for driverless vehicles and aims to reduce the risk of extracting information from undesired obstacles. We define the faults of a LiDAR navigation system, derive the integrity risk equation, and suggest landmark environments to reduce the risk of fault-free position error and data association faults. We also present a method to quantify feature extraction risk using reflective tape on desired landmarks to enhance the intensity of returned signals. The high-intensity returns are used in feature extraction decisions between obstacles and pre-defined landmarks using the Neyman-Pearson Lemma. Our experiments demonstrate that the probability of incorrect extraction is below 10(-14), and the method is sufficient to ensure safety.

关键词： integrity LiDAR urban navigation driverless vehicle

来源：评论

学校读者我要写书评

暂无评论

Reflections on Forty Years of Muqarnas: The Broadened Range of Publication Venues for Islamic Art and Architectural History

引用

MUQARNAS-AN ANNUAL ON THE VISUAL CULTURES OF THE ISLAMIC WORLD 2024年第1期40卷 1-11页

作者： Necipoglu, Gulru Harvard Univ Dept Hist Art & Architecture Aga Khan Program Islamic Architecture Cambridge MA 02138 USA

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：