Occupant Movement Research Articles

Indoor air quality in the university classroom: An experiment and simulation analysis in a tropical climate

Abstract A comfortable classroom environment depends heavily on indoor air quality to maximise productivity and performance. This statement refers to the preliminary survey indicating that most university students spend 90% of their time inside buildings. Each day, between three and six hours are spent in the classroom. However, most classrooms today are equipped with AC units, which restrict air exchange. A major reason is the high temperatures, especially in tropical climates. Overly high CO2 concentrations will have a negative effect on health. The purpose of this research is to identify the indoor air quality of Classroom A.202, Department of Architecture, Diponegoro University, focusing particularly on CO2 concentrations. A combination of experiments and simulations is used in the method. For 10 minutes, an Air Quality Monitor and CONTAM simulation software were used to measure and simulate window openings and occupant movements. The results show that CO2 concentration levels increase as occupants in a room increase and air circulation becomes obstructed. It was found that good air circulation can lower CO2 levels, resulting in an optimal learning environment.

Responses of Vehicular Occupants During Emergency Braking and Aggressive Lane-Change Maneuvers.

To validate active human body models for investigating occupant safety in autonomous cars, it is crucial to comprehend the responses of vehicle occupants during evasive maneuvers. This study sought to quantify the behavior of midsize male and small female passenger seat occupants in both upright and reclined postures during three types of vehicle maneuvers. Volunteer tests were conducted using a minivan, where vehicle kinematics were measured with a DGPS sensor and occupant kinematics were captured with a stereo-vision motion capture system. Seatbelt loads, belt pull-out, and footrest reaction forces were also documented. The interior of the vehicle was 3D-scanned for modeling purposes. Results indicated that seatback angles significantly affected occupant kinematics, with small female volunteers displaying reduced head and torso movements, except during emergency braking with a upright posture seatback. Lane-change maneuvers revealed that maximum lateral head excursions varied depending on the maneuver's direction. The study concluded that seatback angles were crucial in determining the extent of occupant movement, with notable variations in head and torso excursions observed. The collected data assist in understanding occupant behavior during evasive maneuvers and contribute to the validation of human body models, offering essential insights for enhancing safety systems in autonomous vehicles.

According to British Documents, the Economic-Financial Situation in Greece during the Turkish War of Independence and the Efforts of the Governments to Finance the War

Starting on 15 May 1919 with the Greek invasion of Smyrna, the occupation movement in Western Anatolia put the Greek finances in difficulty with an increasing sum from year to year. The Greek governments were able to finance the war with the financial aid provided by the Allies to Greece before the invasion. However, in November 1920, Venizelos lost the elections and resigned as prime minister, and in December of the same year, the exiled King Constantine, who had great problems with the Allies, was restored to the throne, which deeply affected the Allied relations with Greece. After this date, the country was unable to receive foreign aid, and in order to finance the war, it introduced many measures, especially tax rates, which were burdensome to the people. Naturally, this situation led to a weakening of the purchasing power of the people who were oppressed under inflationary policies. Despite the large deficit in the balance of income and expenditure during the war years, the country's international trade continued at an increasing rate, albeit with some troubled periods.

Monitoring the Influence of Hand, Foot, and Mouth Disease: New Guidelines on Patient Care during the 2011-2012 Multiwaves and Multivariant Outbreak in Hai Phong City, Vietnam.

From 2011 to 2012, Northern Vietnam suffered its first large-scale hand, foot, and mouth disease (HFMD) epidemic. Two sets of official guidelines were issued during the outbreak to handle the HFMD crisis. The city of Hai Phong was used as a model to analyze the impact of the released guidelines. A total of 9621 HFMD cases were reported in Hai Phong city from April 2011 to December 2012. Three distinct waves of HFMD occurred. Enterovirus A71 and Coxsackievirus A16 were successively associated with the epidemics. Two periods, before and after the guidelines' release, could be distinguished and characterized by different patient patterns. The time to admission and severity changed notably. Guideline publications help the health system refocus on the 0.5-3 years age group with the highest incidence of the disease. The three waves showed different special distribution, but the main routes of infection were rivers and local secondary roads, most likely through local trade and occupational movements of people.

Energy-efficient ventilation strategies at hospital front desks for minimizing infectious particle dispersion: Considering patient postures and airflow optimization

This research presents a novel examination of infectious particle dispersion at hospital front desks, analysing the impact of different patient postures on particle dynamics. It evaluates the efficacy of various ventilation strategies in mitigating particle spread within this high-risk area. Specifically, this study innovatively assesses particle dispersion associated with three common patient postures: upright standing, sitting in a wheelchair, and lying on a mobile bed. Results showed the baseline ventilation that considers the upright standing patient has the highest particles (34) adhered on the nurse. Particle adherence decreases with the sitting (29 particles) and lying postures (20 particles), underscoring the significant influence of human posture on particle distribution. The key contribution of this study is the identification of an optimized ventilation strategy which installs low-level wall-mounted air supply diffusers and ceiling-mounted exhaust grilles, as demonstrated in Case 3. This strategy effectively reduces particle deposition on the nurses and visitors by 52.9 % and 40 %, respectively. These findings advocate for practical infection control measures, like barriers between nurses and patients, to better protect healthcare workers. The study also suggests that future research should account for more crowded environments and occupant movement to better reflect real-world conditions at hospital front desks.

Dynamic coordinated air supply for moving individuals in industrial settings: Effectiveness evaluation and demonstration

Tracking occupant movement and reducing pollution exposure in industrial settings utilizing intelligent ventilation modes without human intervention is a challenge. This work proposes a dynamic coordinated air supply (DCAS) system incorporating static and dynamic ventilation modules, which is capable of switching air supply modes and adjusting air supply parameters in response to changing occupant positions with the assistance of computer vision technology and Internet of Things (IoT). Air movement and pollutant dispersion in an experimental chamber equipped with a DCAS system during occupant movement are analyzed through computational fluid dynamics with overset mesh method. The feasibility of the dynamic simulation method is verified by a walking experiment in the chamber. Three assessment indicators, namely, inhalation exposure, protection factor, and effective protective ratio, are identified to comprehensively evaluate the pollutant removal effectiveness of DCAS. Results show that the static ventilation module can remarkably reduce the occupant's exposure risk within its protective range. The proposed sliding and rotating modes for the dynamic ventilation module are effective in reducing occupant inhalation exposure during movement if the advance operation strategies are specified to eliminate the negative effects of protection lag. In addition, the feasibility of the IoT architecture-based DCAS system is demonstrated in a schematic laboratory. This work helps drive industrial ventilation development toward smart, healthy purposes.

Multifactor dynamic coupled model for building fire evacuation: Case study of the Karamay Friendship Palace fire

Occupant evacuation during a building fire is a complex system that includes several highly coupled subsystems, such as building characteristics, occupant characteristics, fire behavior, and evacuation behavior. To study the interaction mechanism between these subsystems to maximize occupant safety during fire evacuation in a building, a multifactor dynamic coupled model based on the Fire Dynamic Simulator and floor field cellular automata model for occupant evacuation in a fire was established. In the model, the dynamic impact of smoke diffusion on occupant movement direction and speed, decrease in occupant health points caused by smoke and trampling, and changes in occupant exit choices in the presence of closed exits were considered in detail. The catastrophic fire accident in the Friendship Palace of Karamay, Xinjiang, China, in 1994 was used as the analysis case, in which the spatial model of the Friendship Palace was reconstructed according to real data and architectural design methods. The safety exits open or closed, radius Rtra, possibility of information transmission Psuc, and wait time twait were discussed to study the influence of these parameters on the evacuation process and results. The study shows that the model could reproduce a fire accident well with Rtra = 4, Psuc = 0.5, and twait = 30. The closed exits increased evacuation time by over 120.3 % and resulted in 439 deaths. These conclusions are important for providing better estimates, guiding architectural designs, and enhancing building safety management.

An Improved Zonal Ventilation Control Method of Waiting Hall of High-Speed Railway Station Based on Real-Time Occupancy

The random movement of occupants in a high-speed railway station results in a more complex indoor environment. In this study, the indoor thermal environment and the thermal comfort in summer were investigated via field measurements and questionnaires in the waiting hall of a high-speed railway station. The results showed that there was an uneven horizontal temperature distribution in the area, and over 30% of the passengers were dissatisfied with the air conditioning system. In order to improve the control of the indoor temperature as well as reduce the energy consumption of the air conditioning system, an improved zonal control strategy and AMPC control optimization algorithm based on real-time people are proposed, and different control strategies are modeled and simulated using MATLAB/Simulink. It is concluded that the improved zonal control method proposed in this paper can save 28.04% of the fan energy consumption compared with the traditional control strategy.

The Birth of a New BIM Standard: From PED 2018 to 2023, New Parameters and Workflows "Going Live" for Everyone

Building Information Modelling (BIM) has become the de facto standard for the digital representation of buildings. However, from the pedestrian dynamics perspective, BIM Industry Foundation Classes (IFC) schema specification do not fully support data properties required for two-way data sharing with pedestrian modelling tools. An international team of academic and industry researchers, supported by buildingSMART International (bSI), is developing an Occupant Movement Analysis (OMA) standard. The project is focused on expanding the IFC schema specification to support workflows for pedestrian simulation tools and is close to completion. So far, multiple process maps and a list of data properties synchronised with several representative pedestrian modelling tools have been produced. This list of data properties was then converted into bSI's recommended flexible and machine interpretable Information Delivery Specification (IDS) format for specifying data exchange requirements and to add clarity. Currently, this is undergoing testing and review by the project team. Once completed, it will be submitted to bSI’s committees for review. Also, to support this work, a prototype open-source Add-in has been developed to demonstrate a two-way integrated data sharing between BIM authoring tools and pedestrian simulation tools. This standard will enhance data sharing between BIM authoring and pedestrian modelling tools by facilitating the capturing of the required data and addressing friction in multiple design iterations and reassessment.

Design of energy-absorbing bionic workstation table for trains and research on occupant collision injury

Secondary impact is a significant contributor to occupant injuries in train crashes. To mitigate collision injuries, a workbench with energy-absorbing properties was developed, drawing inspiration from leaf-vein and honeycomb structures. A local collision model of a dummy compartment was established to evaluate the impact of different sandwich thicknesses on occupant injuries. By optimizing the wall thickness of the energy-absorbing sandwich, the optimal gradient parameters were determined. The assessment of occupant collision injury from the workstation table with a graded wall thickness sandwich was conducted using the LSTC Hybrid III 50th seating dummy. The results demonstrate that the workstation table influences the occupant's movement posture during a collision, preventing head impact with the tabletop. Apart from slightly elevated leg injuries in the dummy, which remained within permissible values, the head, neck, and chest injuries were reduced by 98.45%, 48.17%, and 81.18%, respectively.

Impact of human walking on the pollutant removal effectiveness of direction air supply considering environmental disturbances: Dynamic simulation study

Direction air supply (DAS) is a computer vision-assisted ventilation mode designed to address the challenge of respiratory protection during human movement. The DAS parameter design is based on ideal, steady-state air distribution results, but it cannot reflect the dynamic protection performance. This work investigates the effect of human walking on the pollutant removal effectiveness of DAS through computational fluid dynamics simulation with the dynamic mesh method. This work formulates an occupant's movement pattern and implements walking and turning motions using the overset mesh method. To verify the feasibility of the dynamic simulation method, a walking experiment was conducted in an experimental chamber equipped with a DAS system. The evolution of concentration isosurfaces, as well as the concentration, velocity, and static pressure at breathing-zone height are revealed. The negative impacts of three common industrial environmental disturbances: localized high-temperature pollutants, ambient airflow, and distance between the DAS nozzle and the breathing zone, on the protective zone and the DAS barrier against pollutants are analyzed. To comprehensively evaluate the effectiveness of DAS, four assessment indexes are determined: inhalation exposure, protection factor, protective zone area, and effective protective ratio. The inconsistency between the protective zone area and the effective protective ratio needs to be noted. This work confirms the effectiveness of DAS within the protective zone and supports its further application in industrial settings.

Is infrastructure a critical aspect of self-organized entrepreneurial activity?

The limitation of capitalist principles and ethics has long been an issue for self-organized enterprises. Even though capitalist modes of labor organization, administration, and management are expelled from the workplace, issues of growth, investment, production, and circulation remain exposed to dominant forms of production. Nevertheless, communities of solidarity, along with spatial and techno-material settings, constitute the infrastructure of commoning practices in those endeavors. We compare the cases of the factory occupation movement in Argentina and the occupation of the Vio.Me. factory in Greece (2010), where a shift to self-organization emerged in the context of the Argentinian and Greek economic crises. We focus on struggles revolving around the use and ownership of spatial-material infrastructure and the production of use-values, highlighting the emancipatory potential of self-organization. Space and objects appear as a contested terrain, while at the same time, material settings are transformed, through the collectives’ participation in networks of distribution and solidarity.

Studying the impact of building morphology on occupants’ movement using a rule mining approach

In the context of mitigating viral transmission, particularly the case of COVID-19, engineering controls have proven to be highly effective. A critical facet of bolstering the efficacy of engineering controls lies in exploring the correlation between the movements of occupants and the building morphology. While extant investigations have predominantly centered on scenarios involving emergency evacuations or day-to-day wayfinding, a knowledge gap exists in our understanding of how occupants’ movements relate to building morphology.To bridge this gap and furnish a more robust foundation for engineering controls during pandemics, this paper introduces a data-driven methodology tailored to studying this relationship both pre-pandemic and during pandemics. The methodology hinges on two primary datasets: building features and the occupants' movements. Initially, building morphology is characterized by discerning pertinent architectural features distilled from prior research. The tracking of occupants’ movements is achieved through a thorough analysis of occupancy and trajectory data. Subsequently, Association Rule Mining (ARM) is used to investigate meaningful relationships. These generated association rules are subsequently elucidated using the proposed interpretation approach.The study's outcomes underscore the pivotal role played by certain building features, most notably floor size, floor level, and room functions, in shaping patterns of occupancy and transit. Moreover, a comparative analysis of occupants' movements before and during the COVID-19 pandemic demonstrates the tangible benefits of engineering control measures. The research contribution unveils the relationship between occupants and building morphology. It proposes a baseline for conducting investigations on relationships between buildings and occupants. Beyond pandemic preparedness, the implications of this research extend to building design, operation, and management.

Ventilation Performance of Air Duct in Double Loaded Corridor Building: A Case Study

Buildings with double-loaded corridor types are often found in Indonesia and generally function as offices or lecture rooms. This type of building is popular because of its efficient circulation path to accommodate the movement of occupants. However, a wall separating the room from the corridor makes it impossible to put windows to implement a cross-ventilation system due to acoustic problems. Hence, to achieve indoor thermal comfort, this type of building relies on using an air conditioning (AC) system. However, with the WHO's call to reduce the use of AC during the COVID-19 pandemic, it is necessary to evaluate cross-ventilation in double-loaded corridor buildings to meet comfort standards while still preventing acoustic problems due to noise from corridors and other spaces. The study proposes a new natural ventilation system using air ducts placed above the corridor ceiling to create cross-ventilation in lecture buildings. The E-ITERA building was chosen as a case study in this research. The building has a glass facade with several small windows that can be opened outside. The corridor of this building is designed with openings at both ends, allowing for direct connection to the outside air. The walls facing the passage have a single door and four small ventilations on the aisle's upper side. Simulations were carried out in two classrooms on the 3rd floor using CFD (Computational Fluid Dynamics) software. Experiments were carried out to change the size of the air duct and the size of the ventilation on the wall that leads to the corridor. The results showed that the air duct was able to create cross-ventilation. Ventilation performance is improved when the WWR air duct is the same as the WWR window. The highest air velocity in the centre of the room is 0.6 m/s. Doi: 10.28991/CEJ-2023-09-10-06 Full Text: PDF

A Multi-Sensor Fusion Approach Based on PIR and Ultrasonic Sensors Installed on a Robot to Localise People in Indoor Environments.

This work illustrates an innovative localisation sensor network that uses multiple PIR and ultrasonic sensors installed on a mobile social robot to localise occupants in indoor environments. The system presented aims to measure movement direction and distance to reconstruct the movement of a person in an indoor environment by using sensor activation strategies and data processing techniques. The data collected are then analysed using both a supervised (Decision Tree) and an unsupervised (K-Means) machine learning algorithm to extract the direction and distance of occupant movement from the measurement system, respectively. Tests in a controlled environment have been conducted to assess the accuracy of the methodology when multiple PIR and ultrasonic sensor systems are used. In addition, a qualitative evaluation of the system's ability to reconstruct the movement of the occupant has been performed. The system proposed can reconstruct the direction of an occupant with an accuracy of 70.7% and uncertainty in distance measurement of 6.7%.

Generative design for COVID-19 and future pathogens using stochastic multi-agent simulation

We propose a generative design workflow that integrates a stochastic multi-agent simulation with the intent of helping building designers reduce the risk posed by COVID-19 and future pathogens. Our custom simulation randomly generates activities and movements of individual occupants, tracking the amount of virus transmitted through air and surfaces from contagious to susceptible agents. The stochastic nature of the simulation requires that many repetitions be performed to achieve statistically reliable results. Accordingly, a series of initial experiments identified parameter values that balanced the trade-off between computational cost and accuracy. Applying generative design to a case study based on an existing office space reduced the predicted transmission by around 10% to 20% compared with a baseline set of layouts. Additionally, a qualitative examination of the generated layouts revealed design patterns that may reduce transmission. Stochastic multi-agent simulation is a computationally expensive yet plausible way to generate safer building designs.

Teorihistorisk skitsering af den nye protestcyklus

The article proposes a reading of the new cycle of protests that erupted in 2011 with the so-called Arab Spring and the square occupation movements in Souther Europe before moving on to the US with the Occupy movement. The years since 2011 have been marked by a significant rise in the numer of protests, riots and revolts across the world with the years 2011, 2014 and 2019 as preliminary high points. The pandemic and the repressive anti-rebellion measures put in place during the pandemic does not seem to have stopped protests from continuing to take place. The article challenges readings of the contemporary protests that fault them for being desperate, defensive and unpolitical proposing a reading using the notion of refusal put forth by Maurice Blanchot and Dionys Mascolo in 1958 as a prims for understanding the emergence of a new anti-political protest culture.

A mathematical model for assessing transient airborne infection risks in a multi-zone hospital ward

Quantification of the parameters influencing airborne infection risks associated with indoor activities in different settings can help in understanding outbreak dynamics and the effective implementation of mitigation strategies. This is particularly important in hospitals, where the consequence of infections amongst vulnerable individuals can be significant. Despite the transient occupancy and inter-connected nature of hospital wards, the majority of airborne risk models assume steady-state conditions and well-mixed air in a single zone. We propose a multi-zone model with both a fixed and time-varying infectious person. We use an adapted version of the Wells–Riley model to estimate transient airborne virus concentration, and account for time-varying behaviour in the indoor setting. Through a coupling with a CONTAM airflow network model, we incorporate the effects of ventilation patterns on inter-zonal flow rates to represent likely airflow in a realistic hospital ward. We use this approach to explore the difference in predictions from transient versus steady-state models across several scenarios. Results suggest that a steady-state approach could lead to an overestimation of infection risk or underestimation of quanta emission, especially when the infectious person is only present for a short period of time. The difference between models is most apparent in poorly ventilated spaces, illustrating how risks can build over time when infectious occupant movement is more frequent than the removal rate due to ventilation. The model highlights the importance of considering transient factors when assessing infection risks to ensure that the most effective mitigation strategies are implemented to address long and short timescale risks.

Cleanroom air quality: combined effects of ventilation rate and filtration schemes in a laboratory cleanroom

ABSTRACT Ventilation performance and air quality in cleanrooms are affected by several interconnected parameters, and a change in one component can impact the entire system. Furthermore, occupant interactions with the physical environment can influence particle dispersion, disrupt current airflow by introducing new wakes and ultimately decrease ventilation efficacy. As a result, we set up an experimental study to measure the effects of traffic, flowrate and filtration on ventilation performance while a source of contamination was inside the room. Experiments included three types of occupant movements (i.e., NM, WO, WT) and were performed under two different airflow conditions. Three different metrics, namely relative ventilation efficiency (), decay rate (R) and exposure (γ), were introduced to statistically compare changes in ventilation performance in response to different experimental setups. Decay rates obtained for 0.3-micron particles decreased by up to 50% in the presence of occupants. Lowering cleanroom flowrate due to additional filtering can reduced ventilation effectiveness by almost 50%. Care should be exercised when changing filter efficiency because it can reduce the rate of air supply. These findings are especially intriguing in the context of cleanroom retrofit, as reducing air exchange rates was an unintended consequence of improving filter efficiency.

A novel approach for occupants' horizontal and vertical movement modeling in non-residential buildings using Immersive Virtual Environment (IVE)

• Presented a general framework for the analysis of occupant behavior in IVEs • Established an IVE platform for occupant behavior observational experiments • Investigated occupant's horizontal and vertical movements in buildings respectively • Analyzed and extracted key features and typical patterns for occupant's movement • Built agent-based model to simulate stochastic occupant movement in buildings Occupant's movement in buildings is one of the most essential factors that influence building energy consumption. Understanding the movement of occupants in buildings is crucial for building design and operations. The advances in virtual reality (VR), especially immersive virtual environments (IVEs), offer new and cost-effective alternatives for occupant behavior studies in unbuilt buildings at design phase and establishing controlled experimental scenarios. This paper presents a general framework for the investigation, analysis, and modelling of the horizontal and vertical movements of occupants in buildings using IVE experimental platform. We first established an IVE experimental platform and conduct the experiment in IVE platform to observe occupant horizontal and vertical movement in buildings. The collected experimental data were then used to statistically analyze and extract key features of the occupant's vertical and horizontal movement patterns, based on which a set of agent-based models (ABMs) are built to simulate stochastic occupant's horizontal and vertical movement patterns in buildings. The proposed method can efficiently capture the occupants’ movement patterns, therefore creating more realistic ABMs for simulation. The proposed method provides an efficient approach to utilizing IVE technology for occupant movement pattern observations and modeling horizontal and vertical moving patterns for advanced building design and management.