Search Results (6,287)

The accurate and timely acquisition of high-frequency three-dimensional (3D) displacement responses of large structures is crucial for evaluating their condition during seismic excitation on shaking tables. This paper presents a distributed high-speed videogrammetric method designed to rapidly measure the 3D displacement of large shaking table structures at high sampling frequencies. The method uses non-coded circular targets affixed to key points on the structure and an automatic correspondence approach to efficiently estimate the extrinsic parameters of multiple cameras with large fields of view. This process eliminates the need for large calibration boards or manual visual adjustments. A distributed computation and reconstruction strategy, employing the alternating direction method of multipliers, enables the global reconstruction of time-sequenced 3D coordinates for all points of interest across multiple devices simultaneously. The accuracy and efficiency of this method were validated through comparisons with total stations, contact sensors, and conventional approaches in shaking table tests involving large structures with RCBs. Additionally, the proposed method demonstrated a speed increase of at least six times compared to the advanced commercial photogrammetric software. It could acquire 3D displacement responses of large structures at high sampling frequencies in real time without requiring a high-performance computing cluster. Full article

As participatory mapping becomes more ingrained into participatory practices, it is vital to understand what makes a method effective. Through the employment of a participatory mapping experiment within an ongoing urban greening initiative, this research aims at validating two established aggregation methods of spatially explicit data points in participatory mapping. Utilizing a paper mapping activity with community residents, the collected spatial data points were analyzed using both democratic and weighted aggregation. Subsequently, a follow-up study was employed to validate the perceived feeling of ownership among both of the methods in terms of the stakeholders’ sense of community representation within the visual outputs. This research introduces a novel approach to the evaluation of participatory mapping practices. A key finding includes the development of a comprehensive methodological model that explores various aspects of a participatory process. Additionally, a new criterion was presented, stakeholder representation, in which to evaluate effectiveness. The difference between the methods was not found to be significant, as the mapping results revealed a consistent overlap in the areas of interest across the stakeholder groups, suggesting a general public consensus on the local development priorities. These insights hold considerable value for local decisions makers, as agreement areas provide a stable foundation for planning. Lastly, this research contributes to the ongoing efforts to evaluate and standardize participatory mapping methods, while also addressing the potential of varied aggregation methods to enhance effectiveness. Full article

Climate change threatens established agricultural systems and production, driving the need for adaptation and mitigation strategies. Vitiforestry, an alternative cultivation system combining trees and shrubs in the vineyard, promotes environmental sustainability and offers a possible adaptation strategy to climate change. This work scrutinizes the impact of shading on vineyards using an Integrated Model of Vineyard Shading and Climate Adaptation (IMVSCA), supported by a system dynamics approach. This model estimates solar radiation and computes daily and annual trends of insolation, air temperature, and relative humidity to shading and its influence on vineyard growth stages. It also assesses the effects of shading-related extreme weather events and the occurrence of grapevine disease development driven by daily weather conditions and zoning adaptations. The pilot results depict the effects of tree shading on vineyards, namely the impacts of solar radiation and air temperature on vine phenology, pollination, pollen germination, fungal diseases, and the complimentary indicators of grape production and quality. Our modeling framework and findings suggest that vitiforestry could be an interesting climate change adaptation technique, providing a starting point for further studies in this scope. Full article

A simple model to evaluate the effects of relative displacements between the ground anchors of a suspension bridge is proposed. An equation system is defined, which allows for the evaluation of the structural response under a general displacement set of the ground anchor points. Then, the most interesting and likely cases are analyzed in detail with reference to a suspension bridge having geometrical and mechanical characteristics typical of a long-span bridge. A simple procedure for the assessment of variation in cable stress is also given, which can be used to choose the optimum values for stress in cables under dead loads, as a percentage of their strength. The results obtained showed that expected movements do not significantly impact the structure in its lifetime and that the effects become negligible for very long-span bridges. Finally, the results obtained can be easily used for the condition monitoring of suspension bridges. Full article

Dental adhesives are essential in modern restorative dentistry and are constantly evolving. However, challenges like secondary caries from bacterial infiltration at the adhesive–tooth interface persist. While synthetic antibacterial agents in adhesives show promise, safety concerns have shifted interest toward natural options that are biocompatible, sustainable, and effective. Therefore, this study evaluated whether natural antibacterial compounds in dental adhesives can provide effective antimicrobial activity without compromising their integrity. This systematic review followed PRISMA 2020 statement guidelines. Four databases were screened, PubMed, Scopus, EMBASE, and Web of Science, without language or publication date restrictions until July 2024. The selection criteria were in vitro studies in which natural antimicrobial substances were incorporated into dental adhesives and the resulting composites were tested for their antibacterial and physicochemical properties. A quality assessment was conducted on the selected studies. Most of the studies reviewed reported significant antibacterial activity while retaining the adhesive’s integrity, generally achieved with lower concentrations of the natural agents. Higher concentrations increase the antimicrobial effectiveness but negatively impact the adhesive’s properties. This review highlights the promising role of natural antibacterial compounds in enhancing the functionality of dental adhesives while also pointing to the need for continued research to address current challenges. Full article

Accurate 3D object detection is essential for autonomous driving, yet traditional LiDAR models often struggle with sparse point clouds. We propose perspective-aware hierarchical vision transformer-based LiDAR-camera fusion (PLC-Fusion) for 3D object detection to address this. This efficient, multi-modal 3D object detection framework integrates LiDAR and camera data for improved performance. First, our method enhances LiDAR data by projecting them onto a 2D plane, enabling the extraction of object perspective features from a probability map via the Object Perspective Sampling (OPS) module. It incorporates a lightweight perspective detector, consisting of interconnected 2D and monocular 3D sub-networks, to extract image features and generate object perspective proposals by predicting and refining top-scored 3D candidates. Second, it leverages two independent transformers—CamViT for 2D image features and LidViT for 3D point cloud features. These ViT-based representations are fused via the Cross-Fusion module for hierarchical and deep representation learning, improving performance and computational efficiency. These mechanisms enhance the utilization of semantic features in a region of interest (ROI) to obtain more representative point features, leading to a more effective fusion of information from both LiDAR and camera sources. PLC-Fusion outperforms existing methods, achieving a mean average precision (mAP) of 83.52% and 90.37% for 3D and BEV detection, respectively. Moreover, PLC-Fusion maintains a competitive inference time of 0.18 s. Our model addresses computational bottlenecks by eliminating the need for dense BEV searches and global attention mechanisms while improving detection range and precision. Full article

Forests are complex ecosystems that require integrated management to balance economic, social, and environmental dimensions. Conflicting objectives among stakeholders make optimal decision-making particularly challenging. This study seeks to balance the economic gains of forest harvesting with the goals of environmental conservation, with a focus on the Shafarood forest in Northern Iran. We applied multi-objective optimization and game theory to maximize the net present value (NPV) of forest harvesting while enhancing carbon sequestration. The research utilized data on stumpage prices, harvesting costs, tree density, volume per ha, growth rates, interest rates, carbon sequestration, and labour costs. Applying the epsilon-constraint method, we derived Pareto optimal solutions for a bi-objective model, and game theory was applied to negotiate between economic and environmental stakeholders. In the fifth round of bargaining, a Nash equilibrium was achieved between the two players. At this equilibrium point, the economic player achieved NPV from forest harvesting of 9001.884 (IRR 10,000/ha) and amount of carbon sequestration of 159.9383 tons/ha. Meanwhile, the environmental player achieved NPV from forest harvesting of 7861.248 (IRR 10,000/ha), along with a carbon sequestration of 159.9731 tons/ha. Results indicate significant trade-offs but reveal potential gains for both economic and environmental goals. These findings provide a robust framework for sustainable forest management and offer practical tools to support informed decision-making for diverse stakeholders. Full article

Dual fuel combustion has gained attention as a cost-effective solution for reducing the pollutant emissions of internal combustion engines. The typical approach is combining a conventional high-reactivity fossil fuel (diesel fuel) with a sustainable low-reactivity fuel, such as bio-methane, ethanol, or green hydrogen. The last one is particularly interesting, as in theory it produces only water and NO_x when it burns. However, integrating hydrogen into stock diesel engines is far from trivial due to a number of theoretical and practical challenges, mainly related to the control of combustion at different loads and speeds. The use of 3D-CFD simulation, supported by experimental data, appears to be the most effective way to address these issues. This study investigates the hydrogen-diesel dual fuel concept implemented with minimum modifications in a light-duty diesel engine (2.8 L, 4-cylinder, direct injection with common rail), considering two operating points representing typical partial and full load conditions for a light commercial vehicle or an industrial engine. The numerical analysis explores the effects of progressively replacing diesel fuel with hydrogen, up to 80% of the total energy input. The goal is to assess how this substitution affects engine performance and combustion characteristics. The results show that a moderate hydrogen substitution improves brake thermal efficiency, while higher substitution rates present quite a severe challenge. To address these issues, the diesel fuel injection strategy is optimized under dual fuel operation. The research findings are promising, but they also indicate that further investigations are needed at high hydrogen substitution rates in order to exploit the potential of the concept. Full article

Pick-up points (PUPs) have become a very attractive alternative for conventional home deliveries due to the growth of e-commerce. This paper investigates the level of satisfaction of the students (Gen Z) as well as the research, teaching, and administrative staff of the Aristotle University of Thessaloniki (AUTH), Greece, and the University of Enna “Kore”, Italy, implemented in November 2023. Optimizing the PUP users’ satisfaction is contingent upon various aspects, including but not limited to location accessibility, expedient pick-up procedures, unambiguous communication, and ensured item availability. The research recorded information about the users’ knowledge about the specific service, their level of satisfaction, their preferences on when and how they use the service, and information about the types of goods they order using the PUPs as their point of collection. The analysis of the collected data revealed very interesting findings that could be useful to the providers of this service, especially when taking into consideration that the majority of the poll’s participants are familiar with the existence of the PUPs in the Municipality of Thessaloniki, that they use this service mainly occasionally, and that the majority are quite pleased with the level of the provided services (accessibility, availability, safety, and security). For the case of Enna in Sicily, similar trends are shown: a high percentage of respondents are familiar with PUPs, and they use pick-up points occasionally and are pleased with the provided level of service. The comparative statistical analysis makes it possible to compare two contexts located in areas of the Mediterranean, i.e., two urban areas with different population sizes but with similar habits on the part of the university student cluster. Full article

The effect of caffeine on the behavior and sleep patterns of zebrafish larvae, as well as its underlying mechanisms, has been a topic of great interest. This study aimed to investigate the impact of caffeine on zebrafish larval sleep/wake behavior and the expression of key regulatory genes such as cAMP-response element binding protein (CREB) and adenosine (ADA) in the sleep pathway. To begin, the study determined the optimal dose and duration of caffeine exposure, with the optimal doses found to be 31.25 μM, 62.5 μM, and 120 μM. Similarly, the optimal exposure time was established as no more than 120 h, ensuring a mortality rate of less than 10%. The confirmation of these conditions was achieved through the assessment of angiogenesis and the inflammatory reaction. As a result, the treatment time point of 24 h post-fertilization (hpf) was selected to examine the effects of caffeine on zebrafish larval sleep rhythm (48 h, with a light cycle of 14:10). Furthermore, the study analyzed the expression of clock genes (bmal1a, per1b, per2, per3, cry2), adenosine receptor genes (adora1a, adora1b, adora2aa, adora2ab, adora2b), and key regulatory factors (CREB and ADA). The research confirmed that caffeine could induce sleep pattern disorders, significantly upregulate adenosine receptor genes (adora1a, adora1b, adora2a, adora2ab, adora2b) (p < 0.05), and markedly decrease the total sleep time and sleep efficiency of the larvae. Additionally, the activity of ADA significantly increased during the exposure (p < 0.001), and the tissue-specific expression of CREB was also significantly increased, as assessed by immunofluorescence. Caffeine may regulate circadian clock genes through the ADA/ADORA/CREB pathway. These findings not only enhance our understanding of the effects of caffeine on zebrafish larvae but also provide valuable insights into the potential impact of caffeine on human behavior and sleep. Full article

The seeds of Theobroma cacao L. are rich in antioxidant flavonoids such as flavan-3-ols, which are valued for their health benefits. In this context, it is of interest to improve flavanol content in cocoa extracts. The present study aimed at improving the clarification process of an aqueous cocoa extract using protein precipitation and filtration. Five pH modifications and two bentonite amounts were tested for their effects on protein precipitation and flavanol content. Micro- and ultrafiltration as a subsequent step was done by testing three different ceramic membranes (30, 80, and 200 nm). Lower pH in pre-treatment reduced protein content and kept flavanols constant, while at higher pH, flavanols were reduced up to 40%. Larger membrane pores enhanced polyphenol permeation, while smaller pores limited protein permeation. Adjusting pH to the isoelectric point increased protein adsorption, improving filtration quality despite decreased permeate flux. However, membrane fouling results in higher permeate quality due to increased selectivity. Furthermore, the addition of bentonite during filtration reduced both protein and flavanol content in the permeate, similar to the effects seen in the pre-treatment of the supernatant. Optimizing pH and membrane pore size enhances the recovery and quality of polyphenols during filtration, balancing protein removal and flavanol retention. Full article

In this paper, we study the problem of the uniqueness of fixed points for operators defined on subspaces of the space of continuous functions $C[a,b]$ equipped with norms stronger than the supremum norm. We are particularly interested in Hölder spaces since they are natural ranges of integral operators of fractional order. Our goal is to preserve the expected regularity of the fixed points (solutions of the equations) when investigating their uniqueness, without assuming a contraction condition on the space under study. We claim some symmetry between the case of the obtained results and the case of the classical Banach fixed-point theorem in such spaces, even for operators which are not necessarily contractions in the sense of the norm of these subspaces. This result is of particular interest for the study of quadratic integral equations, and as an application example we prove the uniqueness theorem for such a kind equations with general fractional order integral operators, which are not necessarily contractions, in a suitably constructed generalized Hölder space. Full article

Next point-of-interest (POI) recommendation provides users with location suggestions that they may be interested in, allowing them to explore their surroundings. Existing sequence-based or graph-based POI recommendation methods have matured in capturing spatiotemporal information; however, POI recommendation methods based on large language models (LLMs) focus more on capturing sequential transition relationships. This raises an unexplored challenge: how to leverage LLMs to better capture geographic contextual information. To address this, we propose interpretable embeddings for next point-of-interest recommendation via large language model question–answering, named QA-POI, which transforms the POI recommendation task into obtaining interpretable embeddings via LLM prompts, followed by lightweight MLP fine-tuning. We introduce question–answer embeddings, which are generated by asking LLMs yes/no questions about the user’s trajectory sequence. By asking spatiotemporal questions about the trajectory sequence, we aim to extract as much spatiotemporal information from the LLM as possible. During training, QA-POI iteratively selects the most valuable subset of potential questions from a set of questions to prompt the LLM for the next POI recommendation. It is then fine-tuned for the next POI recommendation task using a lightweight Multi-Layer Perceptron (MLP). Extensive experiments on two datasets demonstrate the effectiveness of our approach. Full article

The global VTuber market is experiencing rapid growth, with VTubers extending beyond mere content creators to be utilized in various fields such as social interaction, public relations, and health. VTubers have the potential to expand the existing content market and contribute to increasing economic and public value. This study aims to investigate the perception of VTubers in South Korea and to provide insights that can contribute to the global activation of the VTuber entertainment industry. For this purpose, unstructured data on VTubers from the past three years, during which interest in VTubers has significantly grown in South Korea, was collected. A total of 57,891 samples were gathered from Naver, Daum, and Google, of which 50 highly relevant data points between VTubers and users were selected for analysis. First, key terms such as ‘Broadcast’, ‘YouTube’, ‘Live’, ‘Game’, ‘Youtuber’, ‘Japan’, ‘Character’, ‘Video’, ‘Sing’, ‘Virtual’, ‘Woowakgood’, ‘Fan’, ‘Idol’, ‘Korea’, ‘Twitch’, ‘IsegyeIdol’, ‘Communication’, ‘Worldview’, ‘VTuberIndustry’, ‘Contents’, ‘AfricaTV’, ‘Nijisanji’, and ‘Streamer’ were extracted. Second, CONCOR analysis revealed four clusters: ‘Famous VTubers’, ‘Features of VTubers’, ‘VTuber Industry’, and ‘VTuber Platforms’. Based on these findings, the study offers various academic and practical implications regarding VTubers in South Korea and explores the potential for global growth in the VTuber industry. Full article

Background/Objectives: Facial asymmetry is gaining an increasing diagnostic interest in many clinical contexts. Several three-dimensional surface-based methods have been proposed for its assessment; however, they might provide non-equivalent data. Since there is a lack of comparative studies in these terms, this study aims to compare three methods for assessing the asymmetry of the face and facial thirds, thus addressing whether the potential differences can be considered clinically acceptable or not. Methods: Two ‘maxillofacial’ methods based on the trigeminal nerve distribution and one ‘orthodontic’ method based on reference horizontal planes were used to identify the facial thirds on 3D facial models of 80 Italian healthy adults to calculate the asymmetry of the face, and the upper, middle, and lower thirds of the face differently selected by each method. As a measure of asymmetry, the Root Mean Square value was calculated through a mirroring surface-based registration. Intra- and inter-operator reliability was verified for each method. Differences and interchangeability between the methods were tested, respectively, by two-way repeated measures ANOVA (Analysis of Variance) and Bland–Altman and Similarity Percentage model analysis. Additionally, the time required to perform each method was assessed. Results: All methods demonstrated excellent intra- and inter-operator reliability. While the ANOVA analysis found significant differences (p < 0.001) for the majority of facial Regions of Interest between each method, the Bland–Altman analysis revealed that the differences were clinically acceptable (<0.50 mm) for all facial regions between the trigeminal methods, and for the face and the upper third of the face between the orthodontic method, which was revealed to be faster, and the trigeminal ones. The additional similarity percentage model provided visual support for the complete interchangeability of the two trigeminal methods, as evidenced by the lower Coefficient of Variation value. Conclusions: There is no best method for assessing facial asymmetry that applies to all types of clinical settings, as we have shown that different methods may not be completely interchangeable. However, we suggest that the methods based on the trigeminal subdivision can be used interchangeably in contexts where the morpho-functional analysis of maxillofacial regions with different embryological origins is considered. Thus, the clinical setting imposes the choice of one method over another and, as we have pointed out, the consequent comparison of data with those obtained with methods whose interchangeability has been demonstrated. Full article