检索结果-内蒙古大学图书馆

Optimization of Acoustic Porous Material Absorbers Modeled as Rigid Multiple Microducts Networks: Metamaterial Design Using Additive Manufacturing

SSRN

引用

SSRN 2024年

作者： Mareze, Paulo Henrique Silva, Olavo M. Fonseca, William D'Andrea Brandão, Eric Brandão Godinho, Luis Manuel Cortesão Acoustical Engineering Program Federal University of Santa Maria Roraima Av. 1000 Camobi RS Santa Maria Brazil Graduate Program in Mechanical Engineering Federal University of Santa Maria Roraima Av. 1000 Camobi RS Santa Maria Brazil Graduate Program in Architecture Urbanism and Landscaping Federal University of Santa Maria Roraima Av. 1000 Camobi RS Santa Maria Brazil Graduate Program in Civil Engineering Federal University of Santa Maria Roraima Av. 1000 Camobi RS Santa Maria Brazil Vibration and Acoustics Laboratory Federal University of Santa Catarina Campus Universitário Florianópolis SC Trindade Brazil ISISE Department of Civil Engineering University of Coimbra Coimbra Portugal

This research presents an advanced approach to enhancing sound absorption in porous acoustic metamaterials through the optimization of a micro-duct network. The study employs a combination of analytical and numerical methods, systematically adjusting micro-duct diameters within a 2D grid to optimize absorption coefficients at specific frequency bands. The Finite Element Transfer Method (FETM) is utilized for modeling, supported by a multi-objective function influenced by the surface impedance of the network. This approach ensures practical applicability and manufacturability of the designed metamaterial. A significant aspect of the study is the development of an analytical mobility matrix for each micro-duct, integrated through the Transfer Matrix Method with visco-thermal dissipation theory. This integration results in a physically coherent model. The optimization employs the Method of Moving Asymptotes (MMA), effectively managing the complexity associated with a large number of design variables. Subsequently, the optimized structure is adapted into a 3D grid, facilitating prototype creation using Additive Manufacturing Technology (AMT) with a specific polymer material. The research methodology is validated through four distinct test cases, each demonstrating the efficacy and adaptability of the optimization tools and techniques. Experimental validation, conducted using an impedance tube, indicates a significant shift in the first absorption maximum from 2500 Hz to 1000 Hz, achieved without altering the material thickness. Additional validation through 3D Finite Element Method (FEM) modeling, which includes viscothermal effects, further confirms the acoustic efficiency of the final designs. While the potential for achieving lower sub-wavelength conditions is recognized, the study opts for simpler structures, considering the current limitations of 3D printing technology. This study contributes to both theoretical understanding and practical application in acoustic m

关键词： Ducts

来源：评论

学校读者我要写书评

暂无评论

Design and development of a novel waste container from HDPE-layered bins

引用

Journal of King Saud University - Engineering Sciences 2020年第1期32卷 85-90页

作者： Burguillos, Juanito D. Caldona, Eugene B. Department of Mechanical Engineering School of Engineering and Architecture Saint Louis University Baguio City2600 Philippines Graduate Program School of Engineering and Architecture Saint Louis University Baguio City2600 Philippines Department of Chemical Engineering School of Engineering and Architecture Saint Louis University Baguio City2600 Philippines

It is known that there are many ways to manage food waste, however, no specific work has ever been reported on the easiness and economics of treatment mainly at the source. This study hopes to fulfill the gap by constructing a novel waste bin layered with plastic that can continuously accommodate and decompose food waste produced at the source. After several months of use, the bin has been found to be effective and no foul odor has been detected at least 1 ft away. In addition, produced leachate has been found to be nontoxic and can be used to water plants as evidenced by the pH measurements. Furthermore, introduction of additional features such as covering the bin with a painted cloth and putting a chimney on its top has been observed to enhance the performance. © 2018 The Authors

关键词： Waste treatment

来源：评论

学校读者我要写书评

暂无评论

Relentless Resilience

引用

Journal of Civil Engineering and architecture 2021年第1期15卷 47-56页

作者： Lineu Castello PROPAR/UFRGS Post Graduate Program in ArchitectureFederal University of Rio Grande do SulPorto Alegre90040-060Brazil

The paper observes that one of the most significant changes experienced by global cities in their growth is that(fortunately)they keep a Relentless Resilience of some of their urban *** are clearly perceived as configuring territorial fragmentations,either in extra-or intra-urban location,caused by the obsolescence of uses non-aligned to contemporary life;and territorial discontinuities interspersed along the *** is precisely in these fragments that good opportunities for the smart growth of a global city can be *** represent a trend towards a curtailment of the undesired sprawl and the creation of new places that will somehow act as“gluing”the ***,one of the most striking features of contemporary cities has been the strong tendency to value their old memories through redeveloping their heritage *** newest trend is to reuse them under the generical denomination of“Cultural and Creative Parks”,in line with the ideas of the“creative economy”and the revitalization of brownfields.

关键词： Contemporary cities places resilience creative parks anthropocene

来源：评论

学校读者我要写书评

暂无评论

Preservation of Nutmeg Tree (Myristica fragrans Houtt) used as Bogor's Local Culinary Ingredient for the Strengtheness of Urban Landscape Identity 6

Preservation of Nutmeg Tree (Myristica fragrans Houtt) used ...

引用

6th International Conference of Jabodetabek Study Forum 2018

作者： Samantha, Remiya Nurhayati Syartinilia Magister Program of Landscape Architecture Graduate School IPB University Bogor16680 Indonesia Department of Landscape Architecture Faculty of Agriculture Ipb University Bogor16680 Indonesia

Nutmeg tree (Myristica fragrans) is Indonesian native tree species originating from Maluku Island, especially Ambon and Banda. The spread of nutmeg in Bogor area can be traced back to the Dutch colonial period when different kinds of spices were traded across the Indonesian archipelago and beyond. Having this long history, nutmeg is now widely used in Bogor's culinary. At the national level, it has high economic value and become one of Indonesia's main export products. However, there is little research on nutmeg tree spatial distribution. The objectives of the study were : (1) identify the nutmeg trees spatial distribution in Bogor city (2) mapping the existence and identification of nutmeg trees conditions and growing environment. This research was conducted Bogor City from February - May 2018. The data was obtained through direct interview, study field, and study literature. Data collection is determined based on the distribution of nutmeg trees in Bogor City, and extinct status based on study literature. Furtehermore, the existence of nutmeg trees in Bogor collected used purposive and snowball technique. The results showed that a total of 108 nutmeg trees were found in all sub-districts of Bogor city. These trees grow in a variety of areas such as green corridor, public park, agriculture farm, riverbanks, yard, office park, and cemetery. The results of this study can be used as the basis for determining the preservation strategy and area for nutmeg conservation in Bogor city. © 2020 Published under licence by IOP Publishing Ltd.

关键词： Spatial distribution

来源：评论

学校读者我要写书评

暂无评论

Study on seismic response of large-span cantilevered roofs considering vibration characteristics of main structures

Journal of Structural and Construction Engineering

引用

Journal of Structural and Construction Engineering 2019年第762期84卷 1073-1080页

作者： Arai, Yudai Yamashita, Testuo Architects and Engineers Architecture Program in Graduate School Kogakuin University Japan School of Architecture Kogakuin University Japan

This study demonstrates a method for seismic response evaluation of large-span cantilevered roofs excited by horizontal seismic input. Firstly we identified the vibration characteristics of an actual cantilevered roof by performing microtremor measurement. By analyzing the data, we found that the cantilevered roof had two major vertical vibration modes, the vibration of cantilever itself and the vibration exited by the sway deformation of the main building. When the main structure and cantilevered roof resonate, the response of cantilever increases. In this paper, the method for specifying that response characteristics of cantilevered roofs is discussed. © 2019 Architectural Institute of Japan. All rights reserved.

关键词： Seismic response

来源：评论

学校读者我要写书评

暂无评论

Numerical analysis of the influence of the contact boundary condition and specimen geometry on concrete compressive strength

引用

Procedia Structural Integrity 2023年 47卷 261-267页

作者： Caroline Bremm Luísa Inda Leandro Ferreira Friedrich Sabrina Vantadori Ignacio Iturrioz Luis Kosteski Engineering Post Graduation Program Federal University of Pampa Av. Tiaraju 810 Alegrete 97546-550 Brazil Civil Engineering Graduate Program Federal University of Pampa Av. Tiaraju 810 Alegrete 97546-550 Brazil Program of Mechanical Pos-Graduation Federal University of Rio Grande do Sul Sarmento Leite 425 Porto Alegre 90040-060 Brazil Department of Engineering & Architecture University of Parma Parco Area delle Scienze 181/A 43124 Parma Italy

In the present paper, the influence of the contact boundary condition and specimen geometry on the concrete compressive strength is numerically investigated by using a version of the Lattice Discrete Element Method (LDEM), implemented on Abaqus/Explicit. More precisely, two types of contact boundary conditions are considered and, for each of them, three different slenderness levels (height/width ratio - h/b) are analyzed (that is, h/b = 0.5, 1.0, and 2.0) by considering a square cross-section. Moreover, for h/b = 2.0, a circular cross-section is also examined. Two models are developed: one by using the LDEM and the other by using a hybrid model, combining Finite Elements and LDEs. The results show that both the boundary conditions and the sample geometry influence the axial compressive strength.

关键词： Abaqus concrete compressive strength Lattice Discrete Element Method (LDEM)

来源：评论

学校读者我要写书评

暂无评论

Study of Machine Learning Techniques for Damage Identification in a Beam 10th

Study of Machine Learning Techniques for Damage Identifica...

引用

10th International Conference on Wave Mechanics and Vibrations, WMVC 2022

作者： da Silva Coelho, Jefferson de Sousa, Amanda Aryda Silva Rodrigues Machado, Marcela Rodrigues Dutkiewicz, Maciej Department of Mechanical Engineering University of Brasília Campus Universitário Darcy Ribeiro Faculdade de Tecnologia - Asa Norte DF Brasília Brazil Post-Graduate Program - Integrity of Engineering Materials University of Brasília Campus Universitário Darcy Ribeiro Faculdade de Tecnologia - Asa Norte DF Brasília70910-900 Brazil Faculty of Civil Environmental Engineering and Architecture University of Science and Technology Bydgoszcz85-796 Poland

ISBN: (纸本)9783031157578

Damage is defined as any change to the material, geometry or boundary condition that can modify the structure’s properties or response. In the past, damage identification was performed through periodical inspection, non-destructive testing/non-destructive evaluation, or visual observation. Structural health monitoring (SHM) has emerged to transition from offline damage identification to near real-time and online damage assessment. Hence, SHM is a damage detection strategy to monitor a structure for a period using a series of continuous measurement devices, which then collect the system’s characteristics and subsequently perform statistical analysis to assess the current circumstances and health of the structure. One of the first steps for the study of SHM is damage detection followed by monitoring. Machine Learning (ML) techniques can be used to develop viable algorithms to make potential predictions. ML algorithms are therefore providing the tools needed to enhance the capabilities of SHM systems and provide intelligent solutions to past challenges. Preliminary studies have reviewed that the extension of ML into SHM has dramatically increased the system’s capabilities, providing innovative solutions to different research challenges. This work conducts a study of the use of ML to identify damage in a beam and discuss the challenge of usage, performance and implementation of each technique. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： Decision trees

来源：评论

学校读者我要写书评

暂无评论

STUDY ON THE PROCESS OF INTRODUCING TOWN DEVELOPMENT LEARNING AND STUDENT'S LEARNING THROUGH ITS IMPLEMENTATION

引用

AIJ Journal of Technology and Design 2022年第70期28卷 1635-1640页

作者： Urai, Ryotaro Hashida, Ryohei Kikuchi, Shigetomo Dept. of Advanced Interdisciplinary Studies Graduate School of Engineering The Univ. of Tokyo Japan Program of Architecture Faculty of Engineering Niigata Univ. Japan Faculty of Human-Environment Studies Kyushu Univ. Japan

In this study, we identify the challenges in implementing town development learning using the case of hometown learning we practiced at Koyasan Junior High School. Koyasan is famous as a tourist destination with a World Heritage Site but has been experiencing a population decline in recent years. In collaboration with teachers, we planned a hometown study program targeting the historic city area, including the discovery of the town's charms and issues and proposals for the future, which we implemented through trial and error in actual classes. © 2022 Architectural Institute of Japan. All rights reserved.

关键词： Population statistics

来源：评论

学校读者我要写书评

暂无评论

Modeling supports the implementation of urban greening as a response to the challenges of sustainable spatial planning

引用

Journal of Environmental Management 2025年 386卷 125648页

作者： Kim, Eun Sub Hyun, Jung Hee Kim, Na Yeon Heo, Su Jeong Kim, Da Seul Lee, Dong Kun Low-Carbon and Climate Impact Research Centre School of Energy and Environment City University of Hong Kong Tat Chee Ave Hong Kong Kowloon Tong China Systemic Risk and Resilience Research Group Advancing Systems Analysis International Institute for Applied Systems Analysis Austria Department of Landscape Architecture and Rural System Engineering Seoul National University Seoul08826 Korea Republic of Integrated Major in Smart City Global Convergence Program Seoul National University Seoul08826 Korea Republic of Forest Disaster & Environment Department National Institute of Forest Science Seoul Korea Republic of Interdisciplinary Program in Landscape Architecture Seoul National University Seoul08826 Korea Republic of Specialized Graduate School of Intelligent Eco-Science 4 Dept. of Landscape Architecture Seoul National University Seoul08826 Korea Republic of

Urban greening is critical for sustainable urban development, climate change mitigation, and biodiversity conservation. However, the effectiveness of urban greening varies depending on the specific goals (e.g., enhancing biodiversity, reducing urban heat, or both) and their spatial implementation. To address the spatial variability in the effectiveness of greening, we propose a spatial decision support model based on the non-dominated sorting genetic algorithm-II (NSGA-II). This model aims to optimize urban greening locations to maximize biomass density, mitigate urban heat stress, and improve landscape connectivity. Applied to Suwon City, South Korea, the model's effectiveness was evaluated against a business-as-usual (BAU) scenario across four scenarios: connectivity-based, biomass density-based, heat stress-based, and an integrated-based scenario. The integrated approach, balancing trade-offs between ecological benefits and implementation costs, outperformed the BAU scenario by 8.84 %. Despite highlighting a weaker correlation with heat stress mitigation, this outcome indicates significant improvements in biomass density and landscape connectivity. Our findings underscore the necessity of an integrated planning approach to urban greening, as it can contribute toward attaining urban development goals. Additionally, by proposing an app-based model for policymakers, our outputs should enable the reconciliation of multiple environmental objectives in urban landscapes. © 2025 Elsevier Ltd

关键词： Biotic

来源：评论

学校读者我要写书评

暂无评论

Elastic buckling behavior of spherical triangular grid shells composed of H-shaped steel on rectangular plan

Journal of Structural and Construction Engineering

引用

Journal of Structural and Construction Engineering 2019年第759期84卷 659-667页

作者： Kageyama, Kai Yamashita, Tetsuo Kanebako Structural Eng Architecture Program in Graduate School Kogakuin University Japan School of Architecture Kogakuin University Japan

Latticed shells made of H-shaped steel have been constructed all over the world. This study investigates elastic buckling of spherical latticed shells made of H-shaped steel. Out-of-plane shell-like buckling and in-plane member buckling dominantly occur in the elastic buckling of rigidly jointed latticed shells. An H-shaped section has strong and weak axes. Since bending stiffness on the strong axis is several times of that on the weak axis, in-plane member buckling is more likely to occur than the buckling of the shells made of pipes. In the present study the latticed shells for study were on the square plan of 20m × 20m. The shells were relatively flat where the rise-span ratios of the two central arcs were between 0.075 and 0.125. In the linear-buckling (eigenvalue) analysis, in-plane member buckling appears in the 1st buckling mode in all the FE models. The depth, area and second moment of inertia on the strong axis were uniformly set to 20cm, 25cm2 and 2000cm4, respectively. On the other hand, the second moment of inertia on the weak axis was parametrically changed so that the higher order linear buckling load where shell-like buckling firstly appeared was 1.5, 2.0 and 2.5 times of the 1st linear member buckling load. In addition, two boundary conditions, pin and roller were assumed since roller is often used in actually constructed shells. The higher order linear buckling loads agreed well with the classical shell-like buckling loads calculated using the continuum analogy. To estimate member buckling load itself, the buckling length is required. The buckling length calculated using the linear buckling analysis, is 0.7 and 0.5 times of the member length for the roller and pin supported shells, respectively. In the pin-supported shells, uniform compression is realized but in the roller-supported shells, compression and tension mix especially on the peripheral where the member buckling occurs. The tensioned members connected to the compressed member interfere the

关键词： Buckling

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：