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Effect of Wet−dry Cycles and Water-to-cement Ratios on Cement Paste Carbonation

Journal of Advanced Concrete Technology 2025年第4期23卷 205-222页

作者： Zhao, Zhiwei Oh, Dayoung Kitagaki, Ryoma Zheng, Tianlong Maruyama, Ippei Division of Human Environmental Systems Graduate School of Engineering Hokkaido University Hokkaido Sapporo060-8628 Japan Department of Architecture Graduate School of Engineering The University of Tokyo 113-8685 Japan Department of Environmental Engineering and Architecture Graduate School of Environmental Studies Nagoya University Nagoya464-8603 Japan

Cement production is associated with significant energy consumption and CO2 emissions, whereas concrete waste from demolition and renovation has the potential for CO2 absorption. This study investigated the effects of relative humidity and water-to-cement (w/c) ratio on the carbonation of hardened cement pastes with w/c ratios of 0.4, 0.5, and 0.6. Thermogravimetric analysis, X-ray diffraction, and Fourier transform infrared spectroscopy were used to analyze the carbonated samples, which were exposed to five different constant humidity conditions and underwent five types of wet–dry cycles. The results indicated that higher w/c ratios increased the hydration degree and pore formation, facilitating CO2 diffusion and promoting carbonation. Wet–dry cycles enhanced pore generation and calcium silicate hydrates (C-S-H) decomposition through shrinkage and deformation during the drying process. In addition, the minimum and maximum humidity of the wet–dry cycles influenced the formation of vaterite and amount of vaterite converted to calcite. The highest CO2 uptake after 14 days for WC06-40100 with a w/c ratio of 0.6 exhibited twice that of RH40 and 22% higher than that of RH80 on day 14. Moreover, the amount of CO2 uptake under RH40-100 for 28 days was approximately 17% of the annual CO2 emissions from cement production. © 2025 Japan Concrete Institute. All rights reserved.

关键词： Fourier transform infrared spectroscopy

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Estimate for PCB Pattern Fusing Characteristic Due to Abnormal Current and Safety Design

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Journal of Japan Institute of Electronics Packaging 2025年第3期28卷 242-252页

作者： Horikawa, Tai Marumoto, Yoshinobu Inagawa, Shingo Yamauchi, Tsuneaki Sagara, Takashi Electronics Reliability Engineering Group System Integration and EE Architecture Engineering Department EE and Systems Engineering Division Nissan Motor Co.Ltd 560-2 Okatsukoku Kanagawa Atsugi243-0192 Japan Circuit Board Field Engineering Department Manufacturing and Quality Innovation Center Electronic Materials Business Division Panasonic Industry Co. Ltd. 111 Aza-Ishizuka Fukushima Koriyama963-8556 Japan

If a current overloads a PCB pattern capability, the PCB pattern is heated by the current. The method of stopping abnormal current is pattern fusing. It is important to clarify the pattern fusing characteristics because pattern fusing carries the risk of insulation deterioration due to long-term heating. The risk of a fire hazard can be reduced by taking advantage of the fusing characteristics of PCB patterns. A simple method is proposed based on static approximation without iterative calculations. Model parameters are determined experimentally and can then be used to design safe equipment. © 2025 Japan Institute of Electronics Packaging. All rights reserved.

关键词： Fire hazards

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Multiphysics modeling of surface diffusion coupled with large deformation in 3D solids

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European Journal of Mechanics, A/Solids 2025年 113卷

作者： Boo, Seung-Hwan Kim, Jaemin Division of Naval Architecture and Ocean Systems Engineering Korea Maritime and Ocean University Busan49112 Korea Republic of Department of Mechanical Engineering Changwon National University Changwon51140 Korea Republic of

This study presents a comprehensive theoretical and computational model that explores the behavior of a thin hydrated film bonded to a non-hydrated/impermeable soft substrate in the context of surface and bulk elasticity coupled with surface diffusion kinetics. This type of coupling manifests as an integral aspect in diverse engineering processes encountered in optical interference coatings, tissue engineering, soft electronics, and can prove important in the design process for the next generation of sensors and actuators, especially as the focus is shifted to systems in smaller length scales. The intricate interplay between solvent diffusion and deformation of the film is governed by surface poroelasticity, and the viscoelastic deformation of the substrate. While existing methodologies offer tools for studying coupled poroelasticity involving solvent diffusion and network deformation, there exists a gap in understanding how coupled poroelastic processes occurring in a film attached to the boundary of a highly deformable solid can influence its response. In this study, we introduce a non-equilibrium thermodynamics formulation encompassing the multiphysical processes of surface poroelasticity and bulk viscoelasticity, complemented by a corresponding finite element implementation. This study makes significant contributions to solid mechanics and computational modeling by (i) modeling surface diffusion coupled with a viscoelastic substrate, enabling the study of time-dependent responses critical for practical applications, (ii) providing a robust theoretical framework for coupling two materials (film and substrate) with distinct reference (stress-free) states, including a detailed analytical derivation of the initial state, and (iii) efficiently modeling the thin film using a 2D mesh to avoid the need for a fine 3D solid mesh, thus reducing computational costs while maintaining accuracy. This work contributes valuable insights, particularly in scenarios where the coupl

关键词： Thin films

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Sensing-Assisted Channel Estimation in ISAC systems 14th

Sensing-Assisted Channel Estimation in ISAC Systems

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14th EAI International Conference on Wireless and Satellite systems, WiSATS 2024

作者： Yin, Rui Shi, Yexin Qi, Wei Chen, Xianfu Wu, Celimuge Ji, Yusheng School of Information and Electrical Engineering Hangzhou City University Hangzhou310018 China College of Information Science and Electronic Engineering Zhejiang University Hangzhou310027 China Shenzhen CyberAray Network Technology Company Ltd Shenzhen China Graduate School of Informatics and Engineering The University of Electro-Communications Tokyo182-8585 Japan Information Systems Architecture Research Division National Institute of Informatics Tokyo101-8430 Japan

ISBN: (纸本)9783031862021

In future Sixth-Generation (6G) mobile communication, satellite communication is a crucial means of extending mobile networks worldwide. However, in satellite communication systems, the transmission capacity between ground stations and users has become a bottleneck for satellite communication systems. For this issue, Integrated Sensing and Communication (ISAC) technology and Artificial Intelligence (AI), which has been widely studied, has the potential to offer excellent solutions. This paper explores a Uformer-based sensing-assisted communication system that enhances channel estimation accuracy through the design of a Uformer-based channel estimation enhancement algorithm. By formulating a global optimization problem, we seek to improve resource efficiency through finding the optimal resource allocation schemes. Initially, the system utilizes radar data to obtain reconstructed channels and employs communication data for channel estimation. The proposed neural network model then fuses these data into a new and more accurate channel state information. Finally, we present a resource allocation algorithm and validate the performance of all proposed algorithms through simulations. © ICST Institute for Computer Sciences, Social Informatics and Telecommunications engineering 2025.

关键词： Resource allocation

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Detecting Model Poisoning Attacks Via Dummy Symbol Insertion for Secure Over-the-Air Federated Learning 22

Detecting Model Poisoning Attacks Via Dummy Symbol Insertion...

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22nd IEEE Consumer Communications and Networking Conference, CCNC 2025

作者： Zhou, Hang Chiang, Yi-Han Chen, Caijuan Wang, Xiaoyan Ji, Yusheng National Institute of Informatics Information Systems Architecture Science Research Division Tokyo Japan Osaka Metropolitan University Department of Electrical and Electronic Systems Engineering Osaka Japan Graduate School of Science and Engineering Ibaraki University Hitachi Japan

ISBN: (纸本)9798331508050

With the rapid advancement of intelligent IoT services, the need for high-quality and efficient wireless communication has become increasingly critical for information exchanges and collaborations among intelligent edge devices such as autonomous mobile robots (AMRs), robots in smart factories, and surveillance cameras, etc., Federated Learning (FL) is a promising distributed learning framework by exploring the computation capability on edge devices while protecting data privacy of users. On the other hand, Over-the-Air (OTA) computation techniques is a new paradigm of integrated computation and communication. OTA based FL (OTA-FL) can enhance spectrum efficiency by leveraging the superposition properties of wireless channels for model aggregations. The implementation of OTA-FL on edge devices can further protect user data privacy for clients, improve the throughput of inter-device communications, and enhance the distributed learning performance. However, despite these advantages, the convergence of OTA-FL systems remain vulnerable to model poisoning attacks, presenting significant challenges. In this study, we address these vulnerabilities by proposing a two-phase detection mechanism that secures OTA-FL system while preserving high spectral efficiency. Our simulation results demonstrate that under varying conditions, our approach can make distributed learning more secure and communication-efficient. © 2025 IEEE.

关键词： federated learning model poisoning attack Over-the-air computation secure communication

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Detecting Model Poisoning Attacks Via Dummy Symbol Insertion for Secure Over-the-Air Federated Learning

Detecting Model Poisoning Attacks Via Dummy Symbol Insertion...

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Consumer Communications and Networking Conference, CCNC IEEE

作者： Hang Zhou Yi-Han Chiang Caijuan Chen Xiaoyan Wang Yusheng Ji Information Systems Architecture Science Research Division National Institute of Informatics Tokyo Japan Department of Electrical and Electronic Systems Engineering Osaka Metropolitan University Osaka Japan Graduate School of Science and Engineering Ibaraki University Hitachi Japan

ISBN: (数字)9798331508050

ISBN: (纸本)9798331508067

关键词： Computer aided instruction Data privacy Federated learning Distance learning Wireless networks Computational modeling Surveillance Symbols Throughput Convergence

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Mechanisms of change in accelerated carbonation progress in cement paste under different relative humidity conditions

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Cement and Concrete Research 2025年 195卷

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

This study investigated the evolution of water content and carbonation in OPC cement paste under low, intermediate, and high relative humidity (RH) conditions, emphasizing the role of water in accelerated carbonation and microstructural modifications. Under high RH, the carbonation suppressed after 28 days owing to calcium ion accumulation at the surface, precipitating as calcite. This calcite formation leads to a dense calcium carbonate layer, reducing the gas–liquid interfacial area for CO₂ dissolution and blocking further water evaporation and carbonation process. Low RH conditions cause the agglomeration of calcium silicate aluminate hydrate (C–(A)–S–H), increasing empty space in the microstructure. This facilitates CO₂ penetration but limits CH carbonation due to insufficient water availability. These findings highlight the significance of water distribution and microstructural evolution in CO₂ sequestration, revealing that RH critically influences the progress of carbonation by altering the pore structure and subsequent water availability in cementitious materials. © 2025 The Authors

关键词： Carbonation

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An Efficient Collaborative Task Offloading Approach Based on Multi-Objective Algorithm in MEC-Assisted Vehicular Networks

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IEEE Transactions on Vehicular Technology 2025年

作者： Chen, Shuaijie Li, Wenfeng Sun, Jingtao Pace, Pasquale He, Lijun Fortino, Giancarlo Wuhan University of Technology State Key Laboratory of Maritime Technology and Safety School of Transportation and Logistics Engineering Hubei Wuhan430063 China National Institute of Informatics Information Systems Architecture Research Division Tokyo Japan University of Calabria Department of Informatics Modeling Electronics and Systems Rende87036 Italy

Mobile edge computing assisting vehicular networks to achieve collaborative computing is a significant research area, as it can effectively expand the on-board computational resources, thereby improving the responsiveness of vehicular applications and reducing energy consumption. However, the existing task offloading schemes still have various gaps and face challenges that should be addressed because task offloading problems are usually multi-objective optimization problems (MOOP) and NP-hard problems. In this respect, we formulate a new multi-objective model for vehicle-centered task offloading tacking into account the queuing and computing processes of tasks. The minimization of the average delay time, average energy consumption, and average payment cost for each vehicle is defined as a MOOP. We propose an efficient collaborative offloading approach based on task triage strategy and multi-objective optimization to address the model. Specifically, this approach can be decomposed into two stages. First, a task triage strategy is developed based on a comprehensive analysis of task urgency and task criticality to make offloading decisions for triaged tasks with extreme characteristics. Then, we propose a novel multi-objective optimization framework for the MOOP. Finally, we develop a multi-objective hybrid genetic algorithm that integrates the associative learning immediate memory strategy and genetic operations to solve the MOOP. Extensive experiments and performance evaluations based on real-world traces of taxis demonstrate the effectiveness of the proposed approach. The results indicate that the approach outperforms six other well-known multi-objective algorithms in solving the MOOP. © 1967-2012 IEEE.

关键词： Mobile edge computing

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Self-Adjusting Network Slicing for Dynamic Heterogeneous Task Offloading in UAV-Enabled Mobile Edge Computing

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IEEE Transactions on Cognitive Communications and Networking 2025年

作者： Li, Xulong Mao, Wencan Xu, Xinyi Liu, Yaxi Zhang, Huifeng Huangfu, Wei Long, Keping University of Science and Technology Beijing School of Computer and Communication Engineering Beijing100083 China National Institute of Informatics Information Systems Architecture Science Research Division Tokyo101-8430 Japan Zhejiang Lab Hangzhou311500 China

Unmanned aerial vehicle (UAV)-enabled mobile edge computing (MEC) has received wide attention for its ability to significantly reduce latency with flexible mobile aerial nodes. However, the existing works merely consider a fixed periodic network slicing and usually neglect the characterization of computing tasks in practical applications. Motivated by this, we envision a novel scenario where the dynamics and heterogeneity of users and tasks are considered in UAV-enabled MEC networks. We propose a novel self-adjusting two-timescale network slicing scheme based on the internal mechanism in deep reinforcement learning (DRL) to automatically determine whether and when network slicing needs to be reconstructed. Such a novel scheme balances reconstruction cost and system performance compared with traditional fixed schemes. We build an optimization to minimize total system cost for joint UAV trajectory planning and resource allocation at both network and user slice levels. To tackle this problem, we design a novel self-adjusting two-timescale proximal policy optimization (PPO) algorithm that utilizes the property of the critic network, referred to as SaTPPO. Experiment results manifest the effectiveness of the proposed SaTPPO, and it has a lower system cost than the traditional fixed schemes. Moreover, the proposed SaTPPO outperforms the state-of-the-art baselines concerning effectiveness and efficiency. © 2015 IEEE.

关键词： Micro air vehicle (MAV)

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Residential tree canopy configuration and mortality in 6 million Swiss adults: a longitudinal study

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The Lancet Planetary Health 2025年第3期9卷 e186-e195页

作者： Chi, Dengkai Manoli, Gabriele Lin, Brenda Aerts, Raf Yang, Jun Hahs, Amy Richards, Daniel Meili, Naika Zhu, Yue Qiu, Yeshan Wang, Jing Burlando, Paolo Fatichi, Simone Tan, Puay Yok Singapore–ETH Centre Future Cities Laboratory Global Singapore Laboratory of Urban and Environmental Systems École Polytechnique Fédérale de Lausanne Lausanne Switzerland CSIRO Environment Brisbane QLD Australia Division of Ecology Evolution and Biodiversity Conservation University of Leuven Leuven Belgium Risk and Health Impact Assessment Sciensano Brussels Belgium Department of Earth System Science Institute for Global Change Studies Ministry of Education Ecological Field Station for East Asian Migratory Birds Tsinghua University Beijing China School of Agriculture Food and Ecosystem Sciences Burnley Campus The University of Melbourne Richmond Melbourne VIC Australia Manaaki Whenua – Landcare Research Lincoln New Zealand Institute of Environmental Engineering ETH Zurich Zurich Switzerland Department of Architecture College of Design and Engineering National University of Singapore Singapore Department of Civil and Environmental Engineering College of Design and Engineering National University of Singapore Singapore

Background: Residential exposure to trees has been associated with reduced mortality risks. We hypothesise that in addition to tree canopy cover, tree canopy configuration also plays a role in exposure–mortality relationships. As there is limited evidence on this hypothesis, especially longitudinal evidence, we performed a nationwide study to investigate the residential tree canopy configuration–mortality associations in the Swiss population. Methods: In this longitudinal study, the tree canopy cover and configuration metrics within 500 m of individuals’ residences were quantified using high-resolution tree canopy data (1 × 1 m) from 2010 to 2019. We developed single-exposure and multi-exposure time-varying Cox regression models to estimate the associations between the different exposure metrics and natural-cause and cause-specific mortality in Swiss adults (aged from 20 years to 90 years). Mortality and census data were taken from the Swiss National Cohort (SNC). We estimated the hazard ratios (HRs) and corresponding 95% CIs per IQR increase in the metrics adjusting for personal sociodemographic and contextual covariates. We also explored the effect modification by tree canopy cover, PM₁₀, air temperature, urbanisation level, age, sex, and area-based local socioeconomic position. Findings: Our analyses included 6 215 073 individuals from the SNC between 2010 and 2019. In the fully adjusted single-exposure models, we observed protective associations between natural-cause mortality risk and tree canopy cover (IQR 12·4%, HR 0·979 [95% CI 0·975–0·983]) and configuration metrics describing the aggregation (6·3%, 0·831 [0·823–0·840]), and connectedness (2·9%, 0·946 [0·938–0·953]);and detrimental associations with two metrics describing the fragmentation (211 patches per 100 ha, 1·073 [1·066–1·080]) and shape complexity (1·9, 1·094 [1·089–1·100]) of patches. The associations were generally preserved with other common causes of death. According to the multi-expo

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