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Partitioning Uncertainty from Climate Change Inputs on Streamflow Projections in the Bicol River Basin, Philippines

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SSRN 2025年

作者： Bañares, Ernie Nograles Mehboob, Muhammad Shafqat Panda, Manas Ranjan Engineering Graduate Program School of Engineering University of San Carlos Cebu City6000 Philippines College of Engineering and Architecture Sorsogon State University Sorsogon City4700 Philippines Department of Civil Engineering School of Engineering University of San Carlos Cebu City6000 Philippines Department of Civil & Environmental Engineering Yonsei University Seoul Korea Republic of

Increasing threats to global water resources from climate change emphasize the importance of comprehending its impacts on hydrology for effective water management. This article quantifies climate input uncertainty in streamflow projections for the Libmanan-Pulantuna Watershed (LPW) in the Bicol River Basin, Philippines. Using the Water Evaluation and Planning (WEAP) model, we simulated streamflow based on future climate projections (FCPs) from Intergovernmental Panel on Climate Change (IPCC) greenhouse-gas emission scenarios, utilizing Coupled Model Intercomparison Project phases 5 (CMIP5) and 6 (CMIP6) datasets. Four Global Circulation Models (GCMs) and three bias correction techniques (Linear Scaling, Quantile Mapping, and Detrended Quantile Mapping) were applied. Results showed significant differences between the CMIP datasets, with raw CMIP6 better capturing historical climate patterns. Bias correction methods reduced projection biases in precipitation and air temperatures. Projections revealed increasing low flows and decreasing high flows, especially under high-emission scenarios, worsening water shortages during critical periods. Analysis of Variance (ANOVA) showed that climate models were a major source of uncertainty in hydrological projections. Combined FCPs and GCMs contributed to 50%-75% of total uncertainty across flow percentiles and future periods (near-future, mid-future, far-future). These findings underscore the importance of careful model selection and effective bias correction for reliable hydrological projections, crucial for water management strategies in areas like the Bicol River Basin, where water resources are essential for communities and ecosystems. © 2025, The Authors. All rights reserved.

关键词： Rivers

Plugging Effect of Fine Pore Water in Opc and LC3 Paste During Accelerated Carbonation Monitored Via Single-Sided Nuclear Magnetic Resonance Spectroscopy

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SSRN 2024年

作者： Cheng, Luge Kurihara, Ryo Ohkubo, Takahiro Kitagaki, Ryoma Suda, Yuya Teramoto, Atsushi Maruyama, Ippei Department of Architecture Graduate School of Engineering The University of Tokyo Tokyo113-8656 Japan Department of Applied Chemistry and Biotechnology Graduate School of Engineering Chiba University Chiba263-8522 Japan Division of Human Environmental Systems Graduate School of Engineering Hokkaido University Sapporo060-8628 Japan Department of Architecture Graduate School of Advanced Science and Engineering Hiroshima University Hiroshima739-8527 Japan Civil Engineering Program Faculty of Engineering University of the Ryukyus Okinawa903-0213 Japan Nagoya University Japan

This study focuses on the investigation of the influence of CO2 concentration on the carbonation process in cementitious paste using ordinary Portlandite cement and limestone-calcined clay cement, specifically on the water content distribution. Employing single-sided nuclear magnetic resonance spectroscopy for water profiling, we revealed that the water content of fine pores (interlayer space and gel pores) was consistent at the carbonation front under accelerated carbonation processes with CO2 concentrations of 5% and 1%, demonstrating the plugging effect where fine pore water governs the carbonation progress. This effect was absent under natural carbonation conditions because of the carbonation process was slower than drying. It was confirmed that the rate-determining mechanisms of natural and accelerated carbonation with CO2 concentrations greater than 1% were different. © 2024, The Authors. All rights reserved.

关键词： Carbonation

GIS-Based Methodology for Crash Prediction on Single-Lane Rural Highways

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Journal of Geographic Information System 2021年第2期13卷 98-121页

作者： Márcia Macedo Emilia Kohlman Rabbani Maria Maia Marlos Macedo Bianca Ferreira Post-Graduate Program in Civil Engineering UPE Recife Brazil Post-Graduate Program in Systems Engineering UPE Recife Brazil Graduate Program in Architecture and Urban Planning UNICAP Recife Brazil

Due to the need to update the current guidelines for highway design to focus on safety, this study sought to build an accident prediction model using a Geographic Information System (GIS) for single-lane rural highways, with a minimum of statistically significant variables, adequate to the Brazilian reality, and improve accident prediction for places with similar characteristics. A database was created to associate the accident records with the geometric parameters of the highway and to fill in the gaps left by the absence of geometric highway plans through geometric reconstitution or semi-automatic extraction of highways using satellite images. The Generalized Estimating Equation (GEE) method was applied to estimate the coefficients of the model, assuming negative distribution of the binomial error for the count of observed accidents. The accident frequency and annual average daily traffic (AADT) were analyzed, along with the spatial and geometric characteristics of 215 km of federal single-lane rural highways between 2007 and 2016. The GEE procedure was applied to two models having three variations of distinct homogeneous segmentation, two based on segments and one based on the kernel density estimator. To assess the effect of constant traffic, two more variations of the models using AADT as an offset variable were considered. The predominant correlation structure in the models was the exchangeable. The principal contributing factors for the occurrence of collisions were the radius of the horizontal curve, the grade, segment length, and the AADT. The study produced clear indicators for the design parameters of roadways that influence the safety performance of rural highways.

关键词： Roads GEE Single-Lane Rural Highways GIS Crash Prediction

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

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Study of Machine Learning Techniques for Damage Identifica...

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

Laminated Solid Timber Slab with Transverse Prestressing Using the Strategy of Interleaved Vertical Displacement of Lamellae

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Journal of civil engineering and architecture 2024年第4期18卷 186-198页

作者： Bianca Bispo dos Reis Jorge Daniel de Melo Moura Marcos Vinício de Camargo Everaldo Pletz Graduate Program in Architecture and Urbanism Londrina State UniversityJardim Portal de Versalhes 1Londrina 86057-970PRBrazil Department of Civil Engineering Federal Technological University of Paraná(UTFPR)Apucarana 86812-460PRBrazil Retired professor Department of Structural Engineering Londrina State UniversityLondrina 86057-970PRBrazil

This article presents a study on the structural behavior of transversely prestressed laminated timber slabs,focusing on an innovative approach:vertically misaligned *** misalignment,achieved by sliding vertically the wooden lamellae rather than aligning them,enhances the slab’s cross-section moment of inertia,thereby improving load-bearing capacity and *** involved two groups of structural size specimens:one with vertically aligned lamellae(control group)and the other with misaligned lamellae(study group).Results showed the study group exhibited 42%superior stiffness and 10%less load capacity compared to the *** typically occurred individually in the lamellae,particularly in those with defects or lower modulus of elasticity,concentrated in the middle third of the slabs’free span where tensile stresses *** a higher number of failed lamellae,the study group demonstrated promising *** of prestressing bar indicated no damage at all in the thread,suggesting potential for reducing bar *** findings offer crucial insights into applying these slabs in timber construction as well as to any kind of construction.

关键词： Transversal prestressed slabs wooden construction plantation wood flexural testing design methodology

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

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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

Rheology and 3d Printing of Alginate Bio-Stabilized Earth Concrete

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SSRN 2023年

作者： Maierdan, Yierfan Armistead, Samuel J. Mikofsky, Rebecca A. Huang, Qiqi Ben-Alon, Lola Srubar, Wil V. Kawashima, Shiho Columbia University Department of Civil Engineering and Engineering Mechanics New YorkNY10027 United States Columbia University Graduate School of Architecture Planning and Preservation New YorkNY10027 United States University of Colorado Boulder Department of Civil Environmental and Architectural Engineering United States University of Colorado Boulder Materials Science and Engineering Program United States

Driven by the need for sustainable construction solutions, there is renewed interest in earth-based materials. Biopolymer stabilizers can enhance the rheological and structural properties of these materials to facilitate their use in 3D printing. This research examined the influence of sodium alginate on the stability, particle interaction, rheology, and 3D printability of kaolinite, a commonly found clay mineral in soils deemed suitable for construction. Findings revealed that sodium alginate could boost electrostatic interactions to enhance the stability of kaolinite suspensions. This rise in repulsive potential energy also reduced storage modulus and yield stress by orders of magnitude. However, as the alginate content increased beyond its cross-linking concentration (0.12% - 0.6%), a reverse trend was observed, which was attributed to the formation of a three-dimensional polymer network. Furthermore, alginate addition shifted the "printability window" of kaolinite suspensions to mixtures with higher solid contents, which has positive implications on strength and shrinkage. © 2023, The Authors. All rights reserved.

关键词： Biomolecules

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

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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)

Modelling the relationships between local landscape features and habitat suitability of Genji-firefly Luciola cruciata using Random Forests

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Modelling the relationships between local landscape features...

International Symposium on Soft Computing and Intelligent Systems (SCIS)

作者： Tomoya Ogami Shinji Fukuda Hirofumi Kakudo Graduate School of Agriculture Tokyo University of Agriculture and Technology Tokyo Japan Division of Environmental and Agricultural Engineering Tokyo University of Agriculture and Technology Tokyo Japan Program in Architecture Civil and Environmental Engineering Faculty of Engineering and Design Kagawa University Kagawa Japan

Genji-firefly has been one of the key symbols of rural environmental conservation. The species lives underwater as larvae, in the soil when they pupate, and emerges on the ground as adults. Because the habitat conditions of larvae and adults differ greatly, the habitat requirement of Genji-firefly must be clarified over a wide range from instream to the surrounding riparian environment. In this study, we developed a habitat suitability model for Genji-firefly by relating the number of individuals to local landscape features surveyed in a small river in an agricultural watershed. For habitat modelling, Random Forests, a well-known highly predictive machine learning method, was used to model species distributions and to extract quantitative information on their ecological characteristics. As a result, a good agreement was found between observed and modelled number of individuals, although some issues still remain for the test data. We were able to extract local landscape features that characterize the habitat suitability of adult firefly. In future, we plan to deepen our habitat suitability assessment by taking into account uncertainties such as noise originated from absent data.

关键词： Uncertainty Biological system modeling Computational modeling Vegetation Forestry Predictive models Feature extraction