Search Results (74)

This paper aims to evaluate the eco-profile of a building-integrated concentrating photovoltaic system (photovoltaic-cell electrical efficiency: 21.6%; geometrical concentration ratio: 12.5×), extending previous work on the design and energetic/optical performance of this system (University of Lleida, Spain). There is a lack of studies on the eco-profile of these technologies; for this reason, this study is based on environmental life cycle assessment (case study: a building in Barcelona; tools: SimaPro/ecoinvent, inventory-of-carbon-and-energy). Focusing on global warming potential and cumulative energy demand, the impacts range from 341 to 507 kg CO_2.eq/m² and from 5660 to 7505 MJ_prim/m². Energy and greenhouse-gas payback times vary between 2.5 and 6.7 years and are shorter than the useful life of this energy-generating element (pessimistic scenario: 15 years). Avoided-impact calculations have also been performed, verifying the benefits of this system during the use phase. Overall, the results are comparable to those of traditional photovoltaic systems. The additional advantage of the proposed modules is that they serve as an atrium and offer illumination, successfully combining the benefits of concentrating photovoltaics (high efficiency; reduction in the amount of solar-cell material required), two optical media (achromatic doublets), hexagonal solar concentrators (high packing efficiency) and micro-tracking (overcoming limitations of bulky external trackers). Full article

Daylighting in shopping-mall atriums affects both perceived visual quality and the availability of daylight for reducing electric-light use under daylight-responsive control. However, early-stage atrium design still lacks a reproducible workflow that connects field-based user-response evidence with parametric daylight simulation in retail settings. This study develops a weighted-sum design-search workflow for shopping-mall atrium morphology by combining a luminance-based visual satisfaction proxy with spatial daylight autonomy (sDA_300/50%) as an annual daylight-sufficiency indicator. Morphological parameter ranges were derived from a survey of 150 atriums in 26 shopping malls in China, and three prevalent atrium types were retained for simulation-based testing. ClimateStudio/Radiance simulations were used to calculate scene mean luminance and sDA_300/50%, and particle swarm optimization was used as a practical search algorithm under a fixed baseline weighting scenario. The reported high-scoring solutions reached sDA saturation, indicating that the final score differences were mainly governed by the luminance-based satisfaction term within the high-daylight-sufficiency region. This study contributes a retail-oriented, reproducible design-search workflow for early-stage atrium morphology decisions, while the results should be interpreted as scenario-based preferred solutions rather than statistically confirmed global optima or a complete visual-risk/energy-performance assessment. Full article

Indoor environments often contain numerous areas with sparse structural features, such as long corridors, large atriums, and glass curtain walls, and other scenarios. These conditions can lead to difficulties in loop closure detection and accumulated positioning errors, resulting in localization drift or even mapping failure during map construction. This paper proposes an indoor mapping algorithm called IS-LEGO-LOAM that integrates tightly coupled LiDAR-IMU fusion and Scan Context. A tightly coupled LiDAR-IMU odometry is constructed, and an adaptive covariance matrix is designed to solve the problems of abnormal LiDAR echoes and insufficient effective feature extraction caused by sparse indoor feature points. By introducing the Scan Context global descriptor and adopting the strategies of vector nearest neighbor search and similarity score matching, the drift problem in large-scale scenes is alleviated. Finally, validation is performed on the KITTI dataset and in real-world scenarios, respectively. Experiments show that the improved IS-LEGO-LOAM achieves superior mapping performance. Full article

Background: Three-dimensional (3D) mapping of the left atrium (LA) using multipolar high-density (HD) catheters plays a central role in contemporary LA ablation procedures, as accurate and efficient acquisition of anatomical and electrophysiological information is essential. This study benchmarks workflow efficiency during acquisition of a predefined complete HD LA map across four widely used multipolar HD catheter designs. The analysis focuses on efficiency metrics and does not aim to assess mapping quality, arrhythmia interpretation accuracy, or clinical outcomes. Methods: We analyzed 182 consecutive patients from an ongoing cohort undergoing LA procedures, including pulmonary vein isolation and complex LA ablations, using 3D mapping in accordance with current guideline recommendations. Four multipolar HD catheters were applied according to the respective 3D mapping systems: a basket catheter (Orion, Rhythmia), a grid catheter (HD Grid, EnSite X), a penta-spline catheter (PentaRay, Carto 3), and an octa-spline catheter (OctaRay, Carto 3). For each procedure, the time required for acquisition of a complete 3D LA map and the number of acquired points were systematically recorded. LA HD mapping speed was calculated by relating LA volume to the time required for complete map acquisition. Results: The study population had a mean age of 69 years, with a median CHA₂DS₂-VASc score of 3, indicating a cohort with a moderate thromboembolic risk profile. The median LA volume index (LAVI) was 34 mL/m². Patients were distributed across four HD catheter groups, comprising 44 patients in the basket group, 29 in the grid group, 23 in the penta-spline group, and 86 in the octa-spline group. LA mapping speed differed significantly among the groups, with values of 3 mL/min in the basket group, 2.5 mL/min in the grid group, 3.1 mL/min in the penta-spline group, and the highest mapping speed observed in the octa-spline group at 5.9 mL/min. Conclusions: The octa-spline catheter was associated with a significantly higher LA mapping speed compared with other widely used HD catheters. Full article

The Church of San Juan del Hospital in Valencia (Spain) is a Gothic church whose main architectural feature—the western façade—remained unresolved, posing structural and compositional challenges. The intervention addressed this issue while preserving the historical integrity of the building and its heritage context. A systematic methodology was applied, following principles of reversibility, sustainability, and compatibility with medieval ribbed-vault construction. The project resolved five key aspects: completion of the nave’s façade, coverage of the former atrium remains, access from the north courtyard, compositional coherence of the west courtyard front, and integration of the church and museum entrances. Contemporary materials and techniques, including aluminum, recycled wood, and handmade ceramic brick, were selected to harmonize with historic stonework, ensure durability, and minimize environmental impact. Design strategies guided visual perception, emphasizing the lower façade and resolving dispersive compositional elements, while creating functional spaces for ventilation, climate control, and circulation. This intervention demonstrates how a methodical, heritage-sensitive approach can solve complex architectural problems, combining innovation with historical authenticity, and enhancing both the functionality and aesthetic experience of the Church of San Juan del Hospital. Full article

Atrium spaces are widely applied in university buildings. However, achieving effective energy reduction while maintaining adequate daylighting and indoor comfort remains a major challenge at the early design stage. This study identifies key building form design variables significantly influencing atrium daylighting, energy use, and thermal comfort, including building orientation, atrium width-to-depth ratio, atrium aspect ratio, atrium bottom area ratio, and skylight–roof ratio. A multi-objective optimization (MOO) framework is proposed to balance daylight performance, energy consumption, and thermal comfort under fixed envelope parameters. Using typical single- and double-atrium teaching buildings in cold regions as case studies, this research adopts Useful Daylight Illuminance (UDI), Energy Use Intensity (EUI), and Discomfort Time Percentage (DTP) as key indicators to evaluate the interactions between design parameters and building performance. Based on the Pareto-optimal results for the studied prototypes, a south-by-west orientation, moderately slender atrium proportions, relatively compact atrium bottom areas, and medium skylight–roof ratios together yield a balanced performance. Compared with the reference to the initial solution, the optimized solutions reduce EUI by up to 5.66% while also improving UDI and DTP. These results are intended as quantitative references and optimization for early-stage geometric forms design of atrium teaching buildings in cold regions. Full article

The construction sector’s significant energy consumption poses a substantial challenge to achieving global “Carbon Peak and Carbon Neutrality” goals. This study addresses this challenge by proposing a sustainable design framework to optimize atrium spaces in commercial complexes within severe cold regions, where the conflict between high heating energy demands and the pursuit of high-quality spatial experiences is acute. Our climate-adaptive method integrates parametric modeling (Grasshopper) with building performance simulation (Ladybug Tools and Honeybee) to form a multi-objective optimization process using the NSGA-II algorithm. The goal is to simultaneously minimize operational energy (by reducing the seasonal solar heat gain difference, D-RAD) and enhance occupant well-being (by improving useful daylight illuminance, SUMUDI, and thermal discomfort, SUMPPD). Results demonstrate that our framework generated design solutions that significantly improve environmental performance compared to a baseline model: aggregate useful daylight illuminance (SUMUDI) increased by 90.2%, the solar heat gain difference (D-RAD) was reduced by 40.8%, and thermal discomfort (SUMPPD) decreased by 22.7%. This research provides a quantifiable and replicable methodology for sustainable architectural design, contributing directly to the measurement and monitoring of sustainability in the built environment by balancing energy conservation with human-centric design. Full article

Structural heart interventions require precise navigation through tortuous and dynamic cardiac anatomies. However, current guide sheaths often lack sufficient maneuverability for positioning additional catheters. To address these limitations, this paper presents the design and evaluation of a robotic guide sheath with a dual-bendable, compressible tip. The sheath is capable of navigating complex cardiac anatomies for multiple valve interventions. The system consists of a soft continuum sheath tip driven by tendons, a laser-cut compact motorized actuation bed, and a joystick-controlled tendon actuation mechanism. A constant-curvature kinematic model maps actuation inputs to tip bending in 3D, while a custom software interface enables real-time control. Mechanical evaluation (tension, maximum bending, and contraction tests) demonstrated low actuation tension requirements (0.78 N), a wide bending range (from 80° to 90°), and promising tip compressibility (average 5 mm). Trajectory-following tests showed good accuracy, with an average error of 3.34 mm. Catheter guidance trials further validated the sheath’s ability to navigate to the right atrium and guide additional catheters effectively. This work presents a proof-of-concept robotic guide sheath with enhanced maneuverability and adaptability, establishing a foundation for future integration of sensing, automation, and clinical applications. Full article

Background: Well-designed endurance training leads to improved cardiovascular fitness and sports performance in prolonged exercise tasks, with the adaptations depending on multiple factors, including the training modality and the population in question. It is still disputable how the type of training affects myocardial remodeling, and the information on myocardial remodeling by high-intensity interval training (HIIT) is particularly scarce. Methods: The current study investigated changes in cardiac structure after volume-progressive HIIT in running mode. As part of their conditioning program, amateur athletes (mean ± SD age of 18.2 ± 1.0 years) exclusively conducted HIIT in a volume-progressive fashion over 7 weeks (a total of 21 sessions). Peak oxygen uptake as well as 200 m and 2000 m running performance were measured, and transthoracic two-dimensional echocardiography was conducted before and after the intervention. Results: Training improved running performance, increased the peak oxygen uptake and left atrium diameter (from 32.0 ± 2.5 to 33.5 ± 2.3 mm; p = 0.01), and induced ~11% thickening of the left-ventricular posterior wall (7.5 ± 0.7 to 8.2 ± 0.4 mm; p = 0.01) and interventricular septum (7.6 ± 0.7 to 8.6 ± 0.9 mm; p = 0.02), but not the dilation of left-ventricular, right-ventricular, or right atrium chambers. Conclusions: HIIT of just 127 km of running per 8.5 h during 7 weeks was sufficient to improve aerobic capacity and running performance, and induce left-ventricular wall hypertrophy and left atrium dilation, in young healthy athletes. Full article

Underground spaces offer significant potential for sustainable urban development, particularly in cold climate regions where surface thermal fluctuations are extreme. However, optimizing the wind–heat environmental performance of such spaces remains insufficiently explored, especially in relation to spatial morphology. This study addresses this gap by investigating how underground spatial configurations influence thermal comfort and ventilation efficiency. Six representative spatial prototypes—fully enclosed, single-side open, double-side open, central atrium, wind tower, and earth kiln—were constructed based on common underground design typologies. Computational fluid dynamics (CFD) simulations were conducted to evaluate airflow patterns and thermal responses under winter and summer conditions, incorporating relevant geotechnical properties into the boundary setup. The results indicate that deeper burial depths enhance thermal stability, while central atrium and wind tower prototypes offer the most balanced performance in both ventilation and heat regulation. These findings provide valuable design guidance for climate-responsive underground developments and contribute to the interdisciplinary integration of building physics, spatial design, and geotechnical engineering. Full article

The rapid development of urban subway network is prompting higher requirements for daylighting in subway stations. The skylight daylighting space of shallow buried subway stations not only improves the quality of light environment but also brings challenges for the optimization of light and thermal performance, especially in areas with hot summers and cold winters. In this paper, key parameters such as illumination, air temperature, and the black sphere temperature of skylight and artificial lighting areas at stations A and B in Shanghai were tested with a field test system. The results show that the light environment in the skylight areas was significantly improved, but the need for regulation and control of the thermal environment increased. Combined with response surface analysis, 10 sample models for two types of daylighting space (partitioned and open atrium styles) were studied and constructed, including 254 simulated working conditions. The results reveal that design parameters such as the number, aspect ratio, depth of light openings, and skylight angle have significant effects on combined energy consumption. The decentralized double slope roof daylighting space has the best performance in partitioned and open atrium-style public areas, and combined energy consumption can be reduced to 385.14 kWh/m². The optimization strategies proposed in this study can provide a quantitative basis for the skylight design of shallow buried subway stations and an important reference for the design of low-carbon and energy-saving underground spaces. Full article

Underground pedestrian streets play a crucial role in urban spatial systems, yet the positioning of atrium spaces in existing underground walkways is often determined empirically without adequate consideration of spatial rationality in relation to public environmental behavior. Properly designed atrium spaces can significantly enhance spatial quality and pedestrian experience, effectively revitalizing underground environments. This research investigates the rationality of atrium spatial distribution in underground pedestrian streets, with particular emphasis on developing an evaluation framework for assessing atrium layout appropriateness, using pedestrian congregation patterns shaped by spatial network morphology as the primary evaluation criterion. Through comprehensive field observations and computational simulations, the study examines the interaction between existing underground street network configurations and pedestrian behavior, pioneering the application of spatial design network analysis (sDNA) technology to optimize atrium spatial positioning strategies, thereby establishing a more scientific methodology for atrium layout planning. The proposed approach was validated through a case study of Longhu Underground Pedestrian Street in Handan, ultimately providing a systematic method for verifying atrium distribution rationality. The research establishes an innovative framework that integrates computational analysis into underground spatial planning, incorporates pedestrian flow prediction into architectural design processes, and embeds performance-based evaluation into urban renewal initiatives. Findings demonstrate that sDNA technology can accurately predict pedestrian congregation patterns across various underground street configurations, providing a data-driven foundation for assessing atrium location rationality and supporting the optimization of existing underground spaces. These outcomes are expected to offer valuable scientific references for the design and improvement of atrium spatial distribution in future underground pedestrian systems. Full article

Open atrium spaces in university libraries have emerged as a prevalent architectural trend. While increasing daylighting through enlarged glazing areas enhances the indoor environment, it simultaneously introduces significant thermal challenges in cold regions where environmental comfort demands lead to higher energy loads. This study investigates the optimization of daylighting–thermal performance balance through a multi-objective parametric approach to address the inherent conflicts between environmental quality and energy efficiency in atrium design. In this paper, we take the library project in the cold region as a practical case, use the measured data to support the simulation experiment, combine the parametric platform and multi-objective coupling optimization algorithm to carry out digital modeling, and explore the dynamic relationship between the atrium light, heat environment, and the value of energy consumption under the influence of a variety of parameters. The experimental results show that the quality and energy efficiency of the atrium light environment are improved after parameter optimization. The energy consumption per unit area (EUI) is reduced by 84.84 kwh/m²–106.83 kwh/m² while the adequate natural illuminance (UDI) is increased by 5.06–27.64%, which confirms the feasibility of the research and development of the building light–heat coupling optimization technology route and program module. This paper aims to explore the quantitative law of design elements on light–heat balance at the early stage of architectural design and to provide a theoretical basis and reference blueprint for improving the comprehensive decision-making ability of architects in sustainable design and realizing integrated and efficient program decision-making. Full article

The rapid urbanization of developing cities has intensified the challenge of maintaining thermal comfort in buildings, particularly in hot–humid climates. This study investigates the impact of floor level on airflow patterns and indoor temperatures in multi-purpose mid-rise buildings in Onitsha, Nigeria, where increasing urban density and frequent power outages necessitate effective passive cooling strategies. Through a mixed-method approach combining empirical measurements, computational fluid dynamics (CFD) simulations, and thermal performance analysis, the research examined variations in ventilation rates and temperature distributions across different floor levels of a six-story educational building over an annual cycle, focusing on the hottest (27 February), coldest (28 December), most windy (3 April), and least windy (17 September) days. Results revealed distinct floor-level ventilation patterns: upper floors (fourth–fifth) achieved 39–40 air changes per hour (ACH) during hot periods while maintaining temperatures of 30–35 degrees Celsius (°C); middle floors (second–third) showed moderate ventilation (15–22 ACH) but experienced heat accumulation (35–42 °C); and lower floors reached 20 ACH during windy conditions. Temperature stratification varied from 15 °C between floors across the entire building during peak conditions to 7 °C during windy periods. Stack-driven ventilation in upper floors contributed to temperature reductions of up to 3 °C, while wind-driven ventilation promoted uniform temperature distribution across all levels. These findings informed floor-specific design recommendations: hybrid ventilation systems with automated controls, strategic architectural features including a minimum floor level area of 15% for the central atrium, and comprehensive monitoring systems with six temperature sensors per floor. This study provides evidence-based strategies for optimizing thermal comfort in tropical urban environments, particularly valuable for designing energy-efficient buildings in rapidly developing cities with hot-humid climates. Full article

In the context of intensive urban development strategies, the Transit-Oriented Development (TOD) model has emerged as a crucial strategy, requiring a high degree of integration of various functional spaces and traffic flows in transport stations. Complex spaces and traffic flows require an effective Guidance Signage System design to ensure efficient guidance and easy transfers. In order to choose the spatial location of the Guidance Signage System in the connecting space of TOD stations and to improve the efficiency of their guidance and visual saliency, three types of connecting space, namely, channel bifurcation nodes, atrium threshold zones, and sunken plaza interface areas were selected. In total, 18 signage system setup areas were derived from the overlapping visual domains of signage and human visual domains using the Depthmap10 and Massmotion11.5 software (six areas in each type of articulation space), which were then combined with eye-tracking technology to analyze the visual saliency of the signage system’s layout position on the passengers. The experiments show that the signage location affects passengers’ visual attention to a certain extent, and there are differences in the location of high display degrees in different connecting spaces, which require differentiated layouts. This paper summarizes the best spatial location design strategy for the Guidance Signage System according to different connecting spaces, providing more scientific guidance for the spatial location design of the Guidance Signage System for sites connecting spaces. This is essential for enhancing user navigation efficiency, minimizing confusion, and improving overall spatial usability in complex environments. Full article