Search Results (76)

Smart cities use advanced infrastructure and technology to improve the quality of life for their citizens. Collaborative services in smart cities are making the smart city ecosystem more reliable. These services are required to enhance the operation of interoperable systems, such as smart transportation services that share their data with smart safety services to execute emergency response, surveillance, and criminal prevention measures. However, an important issue in this ecosystem is data security, which involves the protection of sensitive data exchange during the interoperability of heterogeneous smart services. Researchers have addressed these issues through blockchain integration and the implementation of smart contracts, where collaborative applications can enhance both the efficiency and security of the smart city ecosystem. Despite these facts, complexity is an issue in smart contracts since complex coding associated with their deployment might influence the performance and scalability of collaborative applications in interconnected systems. These challenges underscore the need to optimize smart contract code to ensure efficient and scalable solutions in the smart city ecosystem. In this article, we propose a new framework that integrates generative AI with blockchain in order to eliminate the limitations of smart contracts. We make use of models such as GPT-2, GPT-3, and GPT4, which natively can write and optimize code in an efficient manner and support multiple programming languages, including Python 3.12.x and Solidity. To validate our proposed framework, we integrate these models with already existing frameworks for collaborative smart services to optimize smart contract code, reducing resource-intensive processes while maintaining security and efficiency. Our findings demonstrate that GPT-4-based optimized smart contracts outperform other optimized and non-optimized approaches. This integration reduces smart contract execution overhead, enhances security, and improves scalability, paving the way for a more robust and efficient smart contract ecosystem in smart city applications. Full article

As climate change concerns, urban congestion, and environmental degradation intensify, cities prioritise cycling as a sustainable transport option to reduce CO₂ emissions and improve quality of life. However, rampant bicycle theft and poor security infrastructure often deter daily commuters and tourists from cycling. This study explores how advanced security measures can bolster sustainable urban mobility and tourism by addressing these challenges. A mixed-methods approach is utilised, incorporating primary survey data from Slovenia and secondary data on bicycle sales, imports and thefts from 2015 to 2024. Findings indicate that access to secure parking substantially enhances users’ sense of safety when commuting by bike. Regression analysis shows that for every 1000 additional bicycles sold, approximately 280 more thefts occur—equivalent to a 0.28 rise in reported thefts—highlighting a systemic vulnerability associated with sustainability-oriented behaviour. To bridge this gap, the study advocates for an innovative security framework that combines blockchain technology and Non-Fungible Tokens (NFTs) with encrypted Quick Response (QR) codes. Each bicycle would receive a tamper-proof QR code connected to a blockchain-verified NFT documenting ownership and usage data. This system facilitates real-time authentication, enhances traceability, deters theft, and builds trust in cycling as a dependable transport alternative. The proposed solution merges sustainable transport, digital identity, and urban security, presenting a scalable model for individual users and shared mobility systems. Full article

Adobe churches are representative of Andean architectural heritage, yet their structural vulnerability to seismic events remains a significant concern. This study evaluates the seismic performance of the 17th-century Church of Santo Tomás de Aquino in Rondocan, Peru, an adobe building that underwent conservation work in the late 1990s. The assessment combines in situ inspections and experimental testing with advanced nonlinear numerical modeling. A finite-element macro-model was developed and calibrated using sonic and ambient vibration tests to replicate the observed structural behavior. Nonlinear static (pushover) analyses were performed in the four principal directions to identify failure mechanisms and to evaluate seismic capacity using the Peruvian seismic code. Kinematic limit analyses were conducted to assess out-of-plane mechanisms using force- and displacement-based criteria. The results revealed critical vulnerabilities in the rear façade and lateral walls, particularly in terms of out-of-plane collapse, while the main façade exhibited a higher capacity but a brittle failure mode. This study illustrates the value of advanced numerical simulations, calibrated with field data, as effective tools for assessing seismic vulnerability in historic adobe buildings. The outcomes highlight the necessity of strengthening measures to balance life safety requirements with preservation goals. Full article

Prefabricated unidirectional carbon fiber reinforced polymer (CFRP) composite strips are extensively used as a means of infrastructure rehabilitation through adhesive bonding to the external surface of structural concrete elements. Most data to date are from laboratory tests ranging from a few months to 1–2 years providing an insufficient dataset for prediction of long-term durability. This investigation focuses on the assessment of the response of three different prefabricated CFRP systems exposed to water, seawater, and alkaline solutions for 5 years of immersion in deionized water conducted at three temperatures of 23, 37.8 and 60 °C, all well below the glass transition temperature levels. Overall response is characterized through tensile and short beam shear (SBS) testing at periodic intervals. It is noted that while the three systems are similar, with the dominant mechanisms of deterioration being related to matrix plasticization followed by fiber–matrix debonding with levels of matrix and interface deterioration being accelerated at elevated temperatures, their baseline characteristics and distributions are different emphasizing the need for greater standardization. While tensile modulus does not degrade appreciably over the 5-year period of exposure with final levels of deterioration being between 7.3 and 11.9%, both tensile strength and SBS strength degrade substantially with increasing levels based on temperature and time of immersion. Levels of tensile strength retention can be as low as 61.8–66.6% when immersed in deionized water at 60 °C, those for SBS strength can be 38.4–48.7% at the same immersion condition for the three FRP systems. Differences due to solution type are wider in the short-term and start approaching asymptotic levels within FRP systems at longer periods of exposure. The very high levels of deterioration in SBS strength indicate the breakdown of the materials at the fiber–matrix bond and interfacial levels. It is shown that the level of deterioration exceeds that presumed through design thresholds set by specific codes/standards and that new safety factors are warranted in addition to expanding the set of characteristics studied to include SBS or similar interface-level tests. Alkali solutions are also shown to have the highest deteriorative effects with deionized water having the least. Simple equations are developed to enable extrapolation of test data to predict long term durability and to develop design thresholds based on expectations of service life with an environmental factor of between 0.56 and 0.69 for a 50-year expected service life. Full article

This systematic review explores how environmental sustainability is addressed in advanced structural systems that utilize innovative materials and technologies such as lightweight designs, adaptive mechanisms, and energy-efficient components. Despite their growing adoption, significant gaps persist across the design–construction–operation continuum, particularly concerning embodied carbon, energy efficiency, material performance, and long-term durability. A total of 61 peer-reviewed studies published between 2013 and 2025 were identified from Scopus and Google Scholar using the PRISMA methodology. The review employed a dual-method approach: a descriptive analysis to examine literature outlets, publication trends, and the frequency of advanced structural topics such as lightweight systems, long-span designs, form and aesthetics, and structural safety, and a thematic analysis using NVivo 14 software, which identified ten key environmental sustainability themes—carbon emissions, thermal performance, energy efficiency, construction waste, life cycle assessment, green certifications, material use, air quality, site and land use, and green environment. While research interest is expanding, limited studies offer comprehensive assessments of Tensile Membrane Structures (TMSs) or Long Span Structures (LSSs), with key challenges including inadequate material optimization and performance under extreme conditions. This review contributes a novel synthesis of existing knowledge by combining a PRISMA-guided selection, descriptive trend analysis, and thematic coding to identify critical gaps and emerging directions, offering a structured foundation for future research and practical strategies in designing environmentally sustainable advanced structures. Full article

Background: Irritable bowel syndrome (IBS) is a prevalent disorder of gut–brain interaction (DGBI) with a negative impact on quality of life and healthcare expenditure. This study aimed to investigate sex-based differences in a large cohort of IBS patients from a multiracial safety-net hospital. Methods: An electronic query was performed using the International Classification of Diseases, 9th Revision (ICD-9) coding to identify 740 outpatients with IBS between 1 January 2005 and 30 September 2007. Demographic data and ICD-9 coded comorbidities were extracted from electronic records. Data analysis used descriptive statistics and multiple logistic regression analyses. Results: Comorbid anxiety and depression were significantly more prevalent in female patients (A:24%, p = 0.03; D:29%, p = 0.008) compared with male patients. White female IBS patients had a higher risk for anxiety but not depression compared with non-White patients (p = 0.02). Female sex (p = 0.02), obesity (p = 0.007), and age above fifty (p = 0.02) but not race/ethnicity were significant risk factors for depression. IBS with constipation was more prevalent in female patients (p = 0.005) and in Hispanic compared with non-Hispanic patients (p = 0.03). Conclusions: Significant sex-based and racial/ethnic differences were identified related to body mass index (BMI), age, and IBS subtypes in this study. Comorbid mood disorders occurred significantly more frequently in female patients, and risk factors for comorbid depression included female sex, older age, and obesity but not race/ethnicity. Full article

Earthquakes, as a common natural disaster, frequently occur in close proximity to human activities. Researchers have developed a series of techniques to enhance the seismic performance of typical reinforced concrete frame structures, thereby improving these buildings’ ability to protect human life. How to retrofit and upgrade existing reinforced concrete frame structures with insufficient seismic performance in accordance with current codes and policy requirements, and how to appropriately incorporate new seismic isolation and energy dissipation technologies to enhance their seismic performance, are the focus of this study. This study adopts a data-driven approach that combines both quantitative and qualitative analyses. Relevant literature was collected from the Web of Science database using specific search criteria. This study visualizes both the historical and recent trends within the scientific field and analyzes keyword frequency to identify key areas for future research. Based on frame structures, the paper reviews novel seismic enhancement techniques for structural systems, including frame–shear wall systems, energy-dissipating buckling-restrained braces (BRBs), and seismic isolation bearings. By integrating traditional structural systems with new technologies, a novel structural system is established to ensure the safety of buildings in high-intensity seismic hazard zones. The results indicate that compared with traditional reinforced concrete frame structures, the new structural system increases energy dissipation by approximately 45% on average. Among these techniques, seismic isolation technology, although more costly, exhibits the best seismic performance and is suitable for new high-priority projects; BRB technology offers a balance between economy and effectiveness, making it the first choice for retrofitting existing buildings; and the frame–shear wall system requires an optimized layout to enhance its cost effectiveness. Full article

The purpose of this study is mainly to investigate, through fragility curves, the effect of soil–structure interaction (when it is neglected during design) on damage probability. It also examines how realistic it is to conduct a performance estimation with rapid assessment methods without considering soil–structure interaction. Three RC frame buildings, with varying numbers of stories, were designed according to the Turkish Seismic Design Code, 2007. Incremental dynamic analyses of the considered structures, both with and without soil–structure interaction (SSI), were performed using 21 ground motion records to determine the damage limits. The cone model with springs was used to take soil–structure interaction into account. The discrete damage probabilities of each considered performance level were calculated, using statistical methods, in terms of elastic spectral acceleration, and continuous fragility curves were obtained. The results show that the effect of SSI on fragility was remarkable and that damage probability generally increases when soil–structure interaction is taken into consideration. The effect of site class becomes significant for life safety and collapse prevention performance levels. The increase in the probability of exceeding the collapse prevention performance level can reach up to 72% due to the existence of SSI. Thus, the results of damage estimation made without considering SSI can sometimes be significantly misleading. Full article

Buildings designed in accordance with Earthquake Codes are expected to survive slight earthquakes without damage, moderate earthquakes with limited and repairable damage, and severe earthquakes without collapse and loss of life. These definitions can be considered as target performance levels; however, whether the performance targets have been achieved is not verified using an engineering parameter. It is assumed that a structure designed in accordance with the code regulations will meet the prescribed controlled damage behavior and that the risk to life safety is minimum. However, studies examining the accuracy of this assumption in terms of the probability of exceeding the targeted performance levels are not widely available in the literature. The purpose of this study is to investigate to what extent this assumption is realistic. The targeted and analytically determined performance of the examined post-tensioned reinforced concrete frame building was compared through the generated fragility curves. The results show that the analytical performance of the examined building does not completely comply with the targeted performance defined by the Turkish Seismic Design Code; therefore, the assumption that a structure designed in accordance with the code will exhibit the targeted performance is not always realistic for each type of building. Full article

Background: Cognitive deficits following ischemic stroke significantly impair quality of life, highlighting the need for effective interventions. This study evaluates the efficacy and safety of extended N-Pep-12 dietary supplementation in enhancing cognitive recovery post-stroke. Methods: In this randomized, open-label, controlled study, 106 patients with supratentorial ischemic stroke were enrolled to receive either 90mg N-Pep-12 or no supplementation daily for 360 days and were followed-up for 360 days. Cognitive function and emotional well-being were assessed using established neuropsychological scales at baseline, 90 days, and 360 days post-stroke. Safety was monitored through adverse events and mortality rates. Results: Significant improvements were observed in the N-Pep-12 group compared to controls, particularly in the Montreal Cognitive Assessment scores at both 90 and 360 days, and in the Digit Symbol Coding scores at 360 days, suggesting enhanced cognitive recovery with extended N-Pep-12 supplementation. A linear regression for a composite outcome analysis at day 360 further confirmed the efficacy of N-Pep-12 in contributing to cognitive improvement. Safety profiles were favorable, with no significant adverse effects attributed to N-Pep-12. Conclusions: Extended dietary supplementation with N-Pep-12 appears to offer a safe and effective approach to support cognitive recovery in ischemic stroke survivors. These findings underscore the potential of the supplement as an add-on intervention for managing post-stroke cognitive impairments. Full article

It is well understood that the dominant approach in the seismic design of structures is to reduce the initial cost while meeting the required safety level, as dictated by compliance codes. Nevertheless, this approach often overlooks the long-term costs that are incurred over the lifetime of the structures. A comprehensive approach is thus required for a design based on life cycle cost (LCC), where both initial and long-term costs are considered. While LCC-based design has been employed on regular structures, irregular structures have not received adequate attention. This research aims to highlight the impact of irregularity on the LCC optimization of tall structures. To do this, a bi-objective heuristic optimization framework is developed to balance the initial and long-term costs. The framework is used to analyze six steel regular and setback irregular structures with 7, 10, and 13 stories. The structures are all designed to meet the life safety performance level. The findings show that the irregular structures reveal a higher sensitivity to variations in initial costs compared to regular structures, which are mainly buildings above 13 stories. We also show that reducing the LCCs of irregular structures requires a higher increase in the initial cost compared to regular structures; for example, in the regular and irregular 13-story structures, a 17% increase in the initial cost resulted in approximately 48% and 40% reductions in the LCCs, respectively. Overall, our results confirm that the long-term costs of irregular structures are more than those of regular ones; this is an important finding that should be considered for the seismic design of tall irregular structures. Full article

For the sake of realizing the safety detection of natural gas and petroleum pipeline welds, this paper designs a ferromagnetic pipeline weld magnetic flux leakage detector based on the calculation of the magnetic circuit of the detection probe, with the magnetization direction perpendicular to the traveling direction. The traditional pipeline magnetic flux leakage detection device uses a detection system mode in which the magnetization direction is parallel to the direction of travel. However, due to the structural characteristics of the weld, the traditional detection system mode is not applicable. Since the weld magnetic flux leakage detector needs to travel along the direction of the weld, the detector designed in this paper rotates the magnetizer 90 degrees along the direction of the weld seam so that the magnetization direction is perpendicular to the direction of travel, breaking through the technical barrier that make traditional magnetic flux leakage detection devices unsuitable for weld detection. The detection device includes a magnetizing structure, a data sampling device, and a driving and traveling device. The magnetic flux leakage signal collected by the detector is converted into a digital image in the form of a grayscale matrix. Using mathematical morphology and chain code algorithms in image processing technology, a pipeline weld defect inversion software system is developed, and a preliminary quantitative analysis of pipeline weld defects is achieved. The application of this technology enables the inspection and protection of oil and gas pipeline welds throughout their life cycle, broadens the scope of existing inspection objects, and is of great safety significance for ensuring national public security. Full article

The majority of fatalities in building fires are attributed to asphyxiation caused by toxic gases. Hydrogen cyanide (HCN) is one of the toxic gases that can be released during a fire, posing a lethal risk to humans even at low concentrations. However, analysis of the risk posed by HCN in fire risk assessments using fire simulations is relatively rare. This study conducted fire simulations to examine the potential risks of HCN to occupants during a fire. The simulations considered various fire conditions in residential buildings by varying fuel types, fire growth rates, and HCN yields. The relative risk score (RRS) was derived based on the time to reach the threshold values of parameters considered critical for life safety. The results of the fire simulations indicated that the RRS for HCN was approximately 20–40 points higher than that of O₂, CO, and CO₂, reaching a maximum of 92 points. However, the risk posed by HCN was found to be limited in comparison to the risks associated with temperature and visibility. Nevertheless, considering that the primary cause of fatalities in fires is asphyxiation due to toxic gases, HCN must be regarded as a critical factor in fire risk assessments. Additionally, since HCN yield values can increase up to nine times depending on temperature and ventilation conditions, the risk posed by HCN could be significantly higher. Full article

In recent decades, the seismic performance of existing reinforced concrete (RC) buildings has played a key role. Nevertheless, the performance and reliability verification of important structural elements such as floors has often been neglected. Floors are primary structural elements that can affect the life cycle life of a building. However, the widespread lack of maintenance planning over time and the original construction practice (which was not always correct) are frequently the cause of unpredictable local or global collapse. In addition, although recent standards and codes recognize the importance of floors by prioritizing their verification with respect to gravitational load conditions, the verification of floor reliability with respect to the load combinations required by modern standards and codes is often not satisfied. Consequently, the intervention costs could be significantly affected by the floor conditions, and their overall amount might even discourage the implementation of interventions. The main purpose of this study is to evaluate the effects (in terms of sustainability) of interventions on residential RC buildings, considering the need to retrofit their existing floors. To this aim, the most vulnerable and potentially most degraded floor types are identified, and their capacity–demand relationships are evaluated. In the case of unverified floors, the main and most popular intervention methods are evaluated and related to the overall intervention costs, taking into account the main uncertainties in performance and cost predictions. The problems and critical issues of floors are key in determining the safety of the building and the cost-effectiveness (i.e., sustainability) of the retrofit intervention. Professionals and decision makers could benefit from the proposed study cost model to define intervention strategies on a regional or national scale. Full article

Surveys on the optimum seismic design of structures reveal that many investigations focus on minimizing initial costs while satisfying performance constraints. Although reducing initial costs while complying with earthquake design codes significantly ensures occupant safety, it may still cause considerable economic losses and fatalities. Therefore, calculating potential earthquake damages over the structure’s lifetime is essential from an optimal Life-Cycle Cost (LCC) design perspective. LCC analysis evaluates economic feasibility, including construction, operation, occupancy, maintenance, and end-of-life costs. The population-based, meta-heuristic Ideal Gas Molecular Movement (IGMM) algorithm has proven effective in solving highly nonlinear mono- and multi-objective engineering problems. This paper investigates the LCC-based mono- and multi-objective optimum design of a 3D four-story concrete building structure using the Endurance Time (ET) method, which is employed for its efficiency in estimating structural responses under varying seismic hazard levels. The novelty of this work lies in integrating the ET method with the IGMM algorithm to comprehensively address both economic and performance criteria in seismic design. The results indicate that the proposed technique significantly reduces minor injury costs, rental costs, and income costs by 22%, 16%, and 16%, respectively, achieving a total reduction of 10% in all structural Life-Cycle Costs, which is considered significant. Full article