Comfort Performance Research Articles

Energy retrofitting of hospital buildings considering climate change: An approach integrating automated machine learning with NSGA-III for multi-objective optimization

In the context of sustainable development, energy-saving renovation of existing buildings can not only effectively reduce energy consumption but also improvement the residential comfort and office environments. This study proposes an optimization method for building energy-saving renovation based on automated machine learning and the NSGA-III algorithm, aiming at efficiently and accurately identifying the best energy-saving renovation schemes. The results showed that automated machine learning could provide a predictive model for multi-objective optimization analysis in a relatively short training time, with an average prediction accuracy of over 95%. And the Stacked Ensemble algorithm and Gradient Boosting Machine algorithm perform the best among all the algorithms considered in this study. Additionally, climate change significantly affects the energy-saving benefits and thermal comfort performance of renovation measures, thereby altering the choice of optimal schemes. The final renovation schemes obtained through the NSGA-III and entropy weight TOPSIS method can achieve an energy saving rate of 22.06% to 26.48% under typical climate scenarios, while also improving thermal comfort time by 31.87% to 43.73%. In future climate scenarios, an energy saving rate of 32.73% to 33.02% and a thermal comfort time of 40.20% to 42.29% can be achieved. Combining these two technologies can quickly and effectively find the best balance among energy consumption, whole life cycle cost, and thermal comfort time. The method proposed in this paper offers new perspectives and tools for researchers in the field of building energy conservation, demonstrating the application potential of automated machine learning and the NSGA-III algorithm in the energy-saving renovation of hospital buildings.

Experimental implementation of skeleton tracking for collision avoidance in collaborative robotics

Collaborative robotic manipulators can stop in case of a collision, according to the ISO/TS 15066 and ISO 10218-1 standards. However, in a human-robot collaboration scenario where the robot and the human share the workspace, a better solution with concerns to production and operator safety would be to perceive in advance the presence of an obstacle and be able to avoid it, thereby completing the task without halting the robot. In this paper, an obstacle avoidance algorithm is tested using a sensor system for real-time human detection; the operator represents a potential dynamic obstacle that can interfere with the robot motion. The sensor system consists of three RGB-D cameras. A custom software framework has been developed in Python exploiting machine learning tools for human skeleton detection. The coordinates of the human body joints relative to the manipulator base are used as input to the obstacle avoidance algorithm. The use of multiple sensors makes it possible to limit the occlusion problem; in addition, the choice of non-wearable sensors goes in the direction of better operator comfort. A series of experimental tests were performed to verify the accuracy of skeleton detection and the ability of the system to avoid obstacles in real time. The human motion caption system, in particular, was validated through a comparison with a commercial system based on wearable IMU sensors widely used and validated in motion capture. There is an NRMSE of 3.23%\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$3.23\\%$$\\end{document} for the RGB-D camera-based skeleton detection system, against an NRMSE of 12.23%\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$12.23\\%$$\\end{document} for the IMU wearable sensor system. Test results confirm that the system is able to avoid collisions with the human body under various conditions, static or dynamic, ensuring a minimum safety distance to any part of the manipulator. In 44 tests in which the operator moves around the robot with possible collisions (at a speed typical of manufacturing operations), the minimum operator-robot distance averaged 208mm\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$208\\,\ extrm{mm}$$\\end{document}, being 200mm\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$200\\,\ extrm{mm}$$\\end{document} the limit safety distance set by algorithm.

Stress Evaluation Using Finite Elements in a Manual Agricultural Tool

This study addresses the imperative need for efficient hand-held agricultural tools, particularly in challenging contexts like hillside agriculture, by focusing on the redesign and evaluation of a manual tillage tool. The objective is to comprehensively assess the stress and fatigue life of a redesigned tool, considering different manufacturing materials such as steels (AISI/SAE 4140, 4130, 1060), A356 aluminum, and nodular cast irons. Employing finite element method simulations and the Von Mises equation, this research confirms an optimal performance within elastic limits for all materials, mitigating the risks of plastic deformation or breakage during normal operation, with Von Mises stresses ranging from 8.39 to 16.30 MPa. All the tools yielded optimal results, meeting the critical requirements for soil penetration resistance, reporting no fatigue failures, and exhibiting useful life values over 1.75 x 1013 years. In terms of ergonomics, A356 aluminum stands out, as it is less heavy and implies a lower effort by the operator, promoting efficient tillage without compromising comfort. This research provides nuanced insights for the design of agricultural tools, emphasizing the harmonious balance between efficiency, longevity, and operator comfort in sustainable practices.

Dynamic inspection data-based analysis of rail base metal irregularities for engineering failure prevention

With the continual increase in train speeds, the requirement for track smoothness has become increasingly critical. Within the railway system of China, the prevalence of short-wave defects, attributed to the rail base metal irregularity, adversely affects the stability of train movement and constitutes a considerable safety risk. However, research into the rail base metal irregularity remains markedly scant, with a conspicuous absence of effective evaluation and identification methodologies. This deficiency critically restricts the capability to mitigate short-wave disturbances arising from such irregularities, negatively impacting the safety and operational stability of railway systems. Therefore, this paper proposes a method for evaluating and identifying the rail base metal irregularity based on dynamic inspection data. Initially, this paper conducts a comprehensive assessment of rail base metal irregularities by analysing wavelength characteristics, frequency amplitude features, and dynamic responses of vehicles. Subsequently, this paper utilises the Synchrosqueezed Wavelet Transform (SWT) technique, which refines the frequency resolution by compressing frequency components within the frequency domain, eliminating cross-frequency interference, and minimising energy dispersion across scale domains, thus accurately delineating the time–frequency attributes of rail base metal irregularity. Building upon the foundation provided by SWT, this paper introduces an identification method employing the Summed Wavelet Power (SWP) across various frequency bands. This approach evaluates the energy variations of different wavelength components relative to changes in mileage, facilitating the identification of track sections with rail base metal irregularity. The efficacy of the proposed methodology is corroborated through the analysis of actual measurement data. The results show that the SWT and SWP techniques can effectively identify rail base metal irregularity, thereby offering substantial support for enhancing the safety and comfort of railway operations.

Model-predictive space heating control for energy flexibility – a case study using a long short-term memory neural network surrogate model and a genetic optimization algorithm

This paper presents a case study where a model predictive control (MPC) logic is developed for energy flexible operation of a space heating system in an educational building. A Long Short-Term Memory Neural Network (LSTM) surrogate model is trained on the output of an EnergyPlus building simulation model. This LSTM model is used within an MPC framework where a genetic algorithm is used to optimize setpoint sequences. The EnergyPlus model is used to validate the performance of the control logic. The MPC approach leads to a substantial reduction in energy consumption (7%) and energy costs (13%) with improved comfort performance. Additional energy costs savings are possible (7–16%) if a sacrifice in indoor thermal comfort is accepted. The presented method is useful for developing MPC systems in the design stages where measured data is typically not available. Additionally, this study illustrates that LSTM models are promising for MPC for buildings.

Finite element analysis study: Topology optimization for the front lower arm with innovative double and complex phase materials

Suspension systems used in vehicles are an important factor affecting comfort, safety, and vehicle performance. These systems are effective in the vehicle's total weight and fuel consumption. However, while lightening the weight, it should also be ensured that the strength is within safe limits. For this purpose, dual-phase (DP) and complex-phase (CP) steel materials were used. In the study, the topology optimization of the front lower suspension arm, designed for a light commercial vehicle, was carried out with the finite element method. As a result of the topology optimization, the weight was reduced by 7.5% compared to the current design, while maintaining the safe strength values. This result will significantly contribute to reducing material costs by using dual-phase (DP) and complex-phase (CP) steel materials, reducing exhaust emissions by lightening vehicle weight, and developing more sustainable designs.

Thermal comfort and mechanical analysis of vigorous diamond and diaper weaves; warp, weft and balanced float fabrics with equal thread densities

Diamond (pointed twill) and diaper (herringbone twill) woven assemblies are considered ideal for applications where thermal insulation, heat retention, wrinkle resistance, strength, softness, and breathability attributes are crucial. Limited research has been found on the optimization of thermal comfort and mechanical performance of warp face, weft face and balanced float diaper and diamond woven assemblies. In this work six different woven assemblies have been engineered using cotton (cellulosic yarn) on a dobby machine, having warp face (4/2) weft face (2/4) and balanced float (3/3) based diamond and diaper weave designs with equal number of thread densities. Thermal comfort (dry fluid transmission, thermal resistance, stiffness, and overall wet fluid management capability) and mechanical (tensile, puncture and tear strength) tests were performed for developed woven fabrics. The results of diamond warp face sample showed the highest dry fluid transmission and volume porosity. Diamond weft face specimens showed the highest thermal conductivity behavior and diaper weft face exhibited the highest overall wet fluid management capability behavior. Stiffness was the highest in diamond balanced float. Diamond warp faced fabric showed the highest tearing durability and diaper weft face showed the highest tensile resilience in mechanical performance attributes.

Comprehensive analysis on building performance enhancement based on selective split-band modulated adaptive thermochromic windows

Thermochromic technology has exciting potential for building applications as it passively modulates its solar transmittance. Existing smart window technologies lead to unnecessary increases in lighting energy consumption during spectral modulation and limited application scenarios. Therefore, spectrally selective modulation is a key direction to improve the performance of smart windows. In this paper, a three-story office building is established in EnergyPlus, and how the characteristic parameters and spectral modulation properties affect the effectiveness of thermochromic windows are thoroughly investigated through actual spectra and hypothetical split-band modulation spectra. A comprehensive human-centered evaluation system is proposed, multiple light zones are divided to investigate in detail the light and thermal environment and comfort performance of office spaces with different orientations of near-window areas and verify the energy-saving effect. The impact of thermochromic adaptive windows on building part loads and equipment efficiency is discussed and the matching of this passive technology with renewable photovoltaics is briefly mentioned. Based on the two-way synergistic perspective of materials and buildings, the results inform the application of smart windows in specific scenarios, throwing light on more cross-cutting research.

On-site evaluation of indoor thermal comfort and energy performance of a liquid-desiccant assisted air-conditioning system in a high-latent-load building

Indoor humidity control is increasingly important because indoor sensible heat ratio decreases to reduce building energy consumption. However, reference vapor compression cooling systems exhibit energy inefficiency and limitations in maintaining indoor thermal comfort. Therefore, this study proposes an alternative heat-pump-driven liquid-desiccant air-conditioning system, independently controlling air temperature and humidity. The reference and proposed systems are applied to a high-latent-load building to investigate their onsite indoor thermal comfort and energy performance empirically and simultaneously under various outdoor summer conditions. The reference system exhibits a thermal comfort satisfaction ratio of 97% only under limited hot and dry weather. Conversely, the thermal comfort satisfaction ratio sharply drops to 2% or less under humid weather. The proposed system consistently achieves a high thermal comfort satisfaction ratio exceeding 90% under various outdoor summer conditions. In empirical comparisons, the proposed system can maintain a thermally comfortable room for an hour while achieving energy savings exceeding 92.4% and 12.1% under warm and humid (rainy season) and hot and humid outdoor conditions, respectively. The proposed system is concluded to consistently maintain indoor thermal comfort while using energy efficiently, demonstrating its widespread applicability for general high-latent-load buildings characterized by low indoor sensible heat ratio values of 0.56 on average.

Comparison of the environmental, energy, and thermal comfort performance of air and radiant cooling systems in a zero-energy office building in Singapore

In an experimental study set in Singapore’s tropical climate, we evaluated the thermal environmental performance, energy consumption, and thermal comfort of air and radiant cooling systems, operating at an operative and air temperature of 26 °C. 78 participants across five groups answered thermal comfort surveys in a crossover study design. Environmental performance metrics indicated that both systems produced similar conditions, with a noticeable difference in air velocity. The mean radiant temperature to air temperature difference was less than 0.5 °C in both systems. The radiant system exhibited a 33 % higher heat flux extraction than the air system and required less electrical power for the transportation of the cooling medium and ventilation air. Overall, the radiant system used 4 % less energy than the air system when controlled at 26 °C and 34 % when operated at 23 °C. Results show that radiant and air systems provided equal thermal comfort in cooling, with over 60 % of participants expressing satisfaction and ∼ 20 % voted neutral thermal satisfaction. ∼ 40 % of participants preferred cooler conditions, and ∼ 30 % desired increased air movement.

Research on the Design of Telemedicine Interface for the Elderly based on the Double Diamond Model

It has become an inevitable trend for China to enter an aging society. The rapid growth of the elderly population has placed a huge burden on the existing medical system. Existing telemedicine APPs do not take into account the characteristics and preferences of the elderly. In order to help the elderly better accept and use the telemedicine system and improve user satisfaction. It is proposed to optimize the telemedicine interface design based on the double diamond model, and the design process around the four stages of exploration, definition, development and interaction is explained in detail. Through semi-structured interviews with the elderly and designers, the user needs of the elderly for telemedicine and the design elements, tools and methods of the telemedicine interface for the elderly were obtained. Draw a user experience journey map and conduct telemedicine interface design practice for the elderly. Improve the elderly’s experience of using telemedicine, improve the comfort performance of products, and promote the development of the elderly health industry.

Determinants of Perceived Comfort: Multi-Dimensional Thinking in Smart Bedding Design.

Sleep quality is an important issue of public concern. This study, combined with sensor application, aims to explore the determinants of perceived comfort when using smart bedding to provide empirical evidence for improving sleep quality. This study was conducted in a standard sleep laboratory in Quanzhou, China, from March to April of 2023. Perceived comfort was evaluated using the Subjective Lying Comfort Evaluation on a seven-point rating scale, and body pressure distribution was measured using a pressure sensor. Correlation analysis was employed to analyze the relationship between perceived comfort and body pressure, and multiple linear regression was used to identify the factors of perceived comfort. The results showed that body pressure was partially correlated with perceived comfort, and sleep posture significantly influenced perceived comfort. In addition, height, weight, and body mass index are common factors that influence comfort. The findings highlight the importance of optimizing the angular range of boards based on their comfort performance to adjust sleeping posture and equalize pressure distribution. Future research should consider aspects related to the special needs of different populations (such as height and weight), as well as whether users are elderly and whether they have particular diseases. The design optimization of the bed board division and mattress softness, based on traditional smart bedding, can improve comfort and its effectiveness in reducing health risks and enhancing health status.

Design and development of ultra-high molecular weight polyethylene seamless sportswear

This study analyses the protection and comfort needs of sportswear and, based on the protection and comfort needs, carries out functional and comfortable integral zoning of sportswear and its structure design. This study uses ultra-high molecular weight polyethylene as the main raw material, and combines the loops characteristics of each structural to design the structure of each part of the seamless sportswear, to realize the zoning design of the seamless sportswear. Through the testing and analysis of the seamless sportswear’s abrasion resistance, cut resistance, contact coolness performance, air permeability and liquid moisture management testing and analysis, it was found that the seamless sportswear developed in this study has excellent protection needs, with abrasion resistance far exceeding the standard of garment use, and can meet the needs of moderate cutting hazards; moreover, the comfort performance meets the physiological needs of the body, and has a better contact coolness performance, with a contact coolness coefficient of up to 0.34. Besides, the selection of the structure of each region of the sportswear meets the requirements of air permeability and moisture-conducting zoning. The research results can provide a basis for the pattern and structure design of UHMWPE seamless sportswear, and realize the rationality and efficiency of garment design.

Human Behavior Adaptability in Responsive Buildings: An Exploratory Study in Workplace Settings

The increased uptake of information and communication technologies (ICTs) is fostering the development of responsive buildings that are aware of and respond to human needs. Current approaches mainly focus on adapting building systems to enhance people’s comfort and energy performance. Little is known about how responsive buildings can inform human behavior adaptability to meet the diverse needs of individuals and organizations within built environments. This study recorded the outcomes of six multi-agent simulation projects exploring human behavior adaptability in different workplace settings. The results have been analyzed through the lenses of ‘place’ theory to extrapolate a framework for human behavior adaptability, jointly considering the characteristics of the spaces, the people that inhabit them, and their activities. This framework provides analytical insights on the design and development of adaptability strategies that consider non-linear interactions and dependencies between the characteristics of the built environment, the needs of the inhabitants, and the goals of organizations.

Portable Dental Chair Innovation in Improving Operator Comfort

Portable Dental Chair Innovation in Improving Operator Comfort

The influence of NaOH/urea treatment on the transfer law of water in cotton fabric

The moisture absorption and water conductivity of fabrics determine the thermal and moisture comfort of textiles and clothing. In this study, the water transfer law in cotton fabrics treated with a NaOH/urea system was investigated. The morphological changes and structural properties of the cotton fabrics before and after treatment were analyzed using scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. Additionally, the relationship between the gaseous and liquid water transfer performance and the fiber morphology and structure was studied. The results indicate that after the NaOH/urea treatment, the surface of the cotton fibers gradually became rougher, and the fibers swelled slightly along the cross-sectional direction. With an increase in treatment time, the axial twist of the fibers decreased, and a trend of dissolution was observed. However, after 5 min of treatment, the cotton fabric tended to adhere to the partially dissolved fibers at the junction of the warp and weft yarns. Although the chemical structure of the cotton fibers did not show significant changes after the treatment, their crystallinity gradually decreased. Following treatment, the air permeability and moisture permeability of the fabric increased, while the wicking height and water retention rate initially increased and then decreased, resulting in an interesting pattern of change. The NaOH/urea treatment also increased the dyeability of the cotton fabrics, and the fastness to rubbing and washing of the fabrics reached grades ≥ 3. Prolonged NaOH/urea treatment enhanced the breaking strength of the cotton fabrics. The establishment of the entropy weight-TOPSIS method to evaluate the moisture transfer performance of fabrics treated with the NaOH/urea system has theoretical significance for the comprehensive analysis of cotton fabrics treated with NaOH/urea and related product development. This study provides a new basis for the comprehensive analysis and evaluation of the water transfer and moisture comfort performance of the fabrics, further advancing the application of NaOH/urea treatment to cotton fabrics, which has promising prospects for the future.

Performance Evaluation of a Nylon-like Polyester Tire Cord Combining the Characteristics of Nylon and Polyester.

A nylon-like polyester tire cord, which combined the characteristics of nylon and polyester tire cords, was designed as the carcass reinforcement material used to meet the increasing demands of the tire industry for performance and impact on the environment. Tires' carcass construction plays a crucial role in affecting handling performance and ride comfort. Small changes in the carcass component can lead to significant improvements in the total tire/vehicle performance. This study evaluated the performance of nylon-like polyester and nylon 6 motorcycle tires. The results showed that the nylon-like polyester tire passed all indoor tests, and post-cure inflation (PCI) could be eliminated, resulting in energy and cost savings. The rolling resistance coefficient of the nylon-like polyester tire was reduced by 6.8% compared to that of the nylon 6 control tire, which could save fuel and have a positive impact on the environment. Nylon-like polyester tire cord extracted from the experimental tire possessed a higher modulus compared to that of nylon 6 tire cord, which could lead to better handling and ride comfort performance. Morphological pictures showed that both nylon-like polyester and nylon 6 cords extracted from tires had a good rubber coverage and comparable adhesion properties.

A Simulation-Based Study on the Impact of Parametric Design on Outdoor Thermal Comfort and Urban Overheating

Under the current energy crisis and climate change, sustainable urban planning and building design are a priority to achieve a net-zero future, as energy use in buildings for thermal comfort is one of the major carbon emission contributors. To adapt to a rapidly growing and stringent urban environment, where buildings are causing more emissions due to more frequent and severe extreme hot weather events, the parametric design approach has great potential and flexibility in providing a sustainable solution by simulating different design scenarios. This study aims to analyse urban geometry and identify the impact of various built environment scenarios on outdoor thermal comfort under certain climates. The Grasshopper program was used along with the Ladybugs plug-in to provide visualised outcomes of outdoor thermal comfort, with simulation models on Rhinoceros 3D Version 7 SR37 (7.37.24107.1500). Comparing the thermal comfort performance of different design scenarios, based on building height, orientation and urban geometry, helps to identify which factors are more impactful on building design. This study demonstrates the workflow of parametric design in analysing the microclimate pattern and outdoor thermal comfort performance of the existing built environment in Melbourne, Australia, to provide an insight for stakeholders and builders to inform better decision-making in urban planning and building design in order to achieve a zero-emission future.

Development of ergo-refined operator's workplace and biophysically actual cost-benefit analysis of riding type self-propelled machines with special reference for female operators.

Female agricultural workers contribute to 37% of the total agricultural workforce in India, however, most self-propelled machinery is designed for male agricultural workers. The primary objective was to determine the impact of the ergo-refined operator's workplace on various aspects of operator performance and comfort, including actuating force, posture, and physiological parameters. Experiments were carried out in real field conditions using a full factorial randomized design. Twelve female operators participated in the study, and measurements were taken for control lever actuating force, operator posture, heart rate, and other relevant parameters. The ergo-refined operator's workplace intervention resulted in significant reductions in actuating force for various control levers, angles of joints, working heart rate (WHR), oxygen consumption rate (OCR), muscle load, and whole-body vibration (WBV) acceleration. These reductions were observed under different operating conditions. The findings suggest that the ergo-refined operator's workplace is effective in enhancing operator comfort and reducing physical strain during the operation of riding type self-propelled machines. It contributes to improved safety, comfort, and operational efficiency for operators working in field conditions. ANOVA and MANOVA analyses confirmed the positive impact of operating conditions and engine speed on the measured parameters when using the ergo-refined operator's workplace.

Influence of air intake from existing shafts on the safety of operating trains

Given the influence of air intake from inclined shafts in existing tunnel ventilation systems on train comfort and aerodynamic safety, a numerical analysis method is used to study the comfort and aerodynamic safety of operating trains under three conditions—inclined shaft closed and inclined shaft open without and with air intake—and to explore the variation law of transient pressure and aerodynamic force (lift coefficient, transverse force coefficient, and overturning moment coefficient). Combined with practical engineering and requirements, the influence of inclined shaft air intake on train operation comfort and aerodynamic safety is analyzed. Through this research, the influence of using air intake from the inclined shaft of an existing tunnel, a ventilation scheme of the new Wushaoling Tunnel, on the comfort and aerodynamic force of trains is revealed, and the comfort and aerodynamic safety of trains in an actual project are evaluated, verifying the rationality of the ventilation scheme of the Wushaoling Tunnel.