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Incorporating intelligence into exit choice model for typical evacuation

Mohammed Shuaib, Zarita Zainuddin

Sains Malaysiana, 2017;46:1997-2005.

Integrating an exit choice model into a microscopic crowd dynamics model is an essential approach for obtaining more
efficient evacuation model. We describe various aspects of decision-making capability of an existing rule-based exit
choice model for evacuation processes. In simulations, however, the simulated evacuees clogging at exits have behaved
non-intelligently, namely they do not give up their exits for better ones for safer egress. We refine the model to endow
the individuals with the ability to leave their exits due to dynamic changes by modifying the model of their excitement
resulted from the source of panic. This facilitates the approximately equal crowd size at exits for being until the end
of the evacuation process, and thereby the model accomplishes more optimal evacuation. For further intelligence, we
introduce the prediction factor that enables higher probability of equally distributing evacuees at exits. A simulation to
validate the contribution is performed, and the results are analyzed and compared with the original model.

Matched MeSH terms: Crowding
Fulltext Characteristics of psychiatric admissions and aspects of overcrowding at the general Hospital, Kuala Lumpur

Chin CN, Kadir AB, Jeyarajah S

Med J Malaysia, 1993 Jun;48(2):135-45.
PMID: 8350788

This study examined admissions, final diagnoses and mean duration of stay of patients in the Psychiatric Wards at the General Hospital, Kuala Lumpur. The male ward was severely overcrowded by 125% over the maximum bed capacity. The majority were psychotic, mainly schizophrenic. The female ward had 76% occupancy, also mainly psychotic. Neurotics, alcohol dependents and personality disorders formed less than 5% of the admissions. There was no difference in the mean duration of stay of patients of both UKM and GHKL Units stratified for diagnosis and disposal except for newly diagnosed schizophrenics. There is an urgent need for more male psychiatric beds/wards.

Matched MeSH terms: Crowding*
Fulltext A single mass gathering resulted in massive transmission of COVID-19 infections in Malaysia with further international spread

Che Mat NF, Edinur HA, Abdul Razab MKA, Safuan S

J Travel Med, 2020 05 18;27(3).
PMID: 32307549 DOI: 10.1093/jtm/taaa059
Matched MeSH terms: Crowding*
Fulltext Using simulation model as a tool for analyzing bus service reliability and implementing improvement strategies

Moosavi SMH, Ismail A, Yuen CW

PLoS One, 2020;15(5):e0232799.
PMID: 32379848 DOI: 10.1371/journal.pone.0232799

Bus services naturally tend to be unstable and are not always capable of adhering to schedules without control strategies. Therefore, bus users and bus service providers face travel time variation and irregularity. After a comprehensive review of the literature, a significant gap was recognized in the field of public transportation reliability. According to literature, there is no consistency in reliability definition and indicators. Companies have their own definition of bus service reliability, and they mostly neglect the passengers' perspective of reliability. Therefore, four reliability indicators were selected in this study to fill the gap in the literature and cover both passengers' and operators' perceptions of reliability: waiting time and on-board crowding level from passengers' perspective, and headway regularity index at stops (HRIS) and bus bunching/big gap percentage from operators' perspective. The primary objective of this research is to improve the reliability of high frequency of bus service and simulation tools currently being used by the public transportation companies. Therefore, a simulation model of bus service was developed to study the strategies to alleviate it. Four different types of strategies were selected and implemented according to Route U32 (Kuala Lumpur) specifications. Model out-put showed that control strategies such as headway-based dispatching could significantly improve headway regularity by almost 62% and the waiting time by 51% on average. Both holding strategies at key stops (previous and Prefol holding) have shown an almost similar impact on reliability indicators. Waiting time was reduced by 44% and 43% after the previous and Prefol Headway strategies were adopted, respectively. However, the implementation of the component of headway-based strategies at the terminal and key stops showed the best impact on reliability, in terms of passenger waiting time. Waiting time and excess waiting time were both significantly reduced by 52.86% and 81.44%, respectively. Nevertheless, the strategies did not show any significant positive effect on the level of crowding during morning peak hours.

Matched MeSH terms: Crowding
Fulltext Crowd density estimation using deep learning for Hajj pilgrimage video analytics

Bhuiyan MR, Abdullah DJ, Hashim DN, Farid FA, Uddin DJ, Abdullah N, et al.

F1000Res, 2021;10:1190.
PMID: 35136582 DOI: 10.12688/f1000research.73156.2

BACKGROUND: This paper focuses on advances in crowd control study with an emphasis on high-density crowds, particularly Hajj crowds. Video analysis and visual surveillance have been of increasing importance in order to enhance the safety and security of pilgrimages in Makkah, Saudi Arabia. Hajj is considered to be a particularly distinctive event, with hundreds of thousands of people gathering in a small space, which does not allow a precise analysis of video footage using advanced video and computer vision algorithms. This research proposes an algorithm based on a Convolutional Neural Networks model specifically for Hajj applications. Additionally, the work introduces a system for counting and then estimating the crowd density.
METHODS: The model adopts an architecture which detects each person in the crowd, spots head location with a bounding box and does the counting in our own novel dataset (HAJJ-Crowd).
RESULTS: Our algorithm outperforms the state-of-the-art method, and attains a remarkable Mean Absolute Error result of 200 (average of 82.0 improvement) and Mean Square Error of 240 (average of 135.54 improvement).
CONCLUSIONS: In our new HAJJ-Crowd dataset for evaluation and testing, we have a density map and prediction results of some standard methods.

Matched MeSH terms: Crowding
Fulltext An M/M/c/K State-Dependent Model for Pedestrian Flow Control and Design of Facilities

Rahman K, Abdul Ghani N, Kamil AA, Mustafa A, Chowdhury MA

PLoS One, 2015;10(7):e0133229.
PMID: 26196124 DOI: 10.1371/journal.pone.0133229

Pedestrian overflow causes queuing delay and in turn, is controlled by the capacity of a facility. Flow control or blocking control takes action to avoid queues from building up to extreme values. Thus, in this paper, the problem of pedestrian flow control in open outdoor walking facilities in equilibrium condition is investigated using M/M/c/K queuing models. State dependent service rate based on speed and density relationship is utilized. The effective rate of the Poisson arrival process to the facility is determined so as there is no overflow of pedestrians. In addition, the use of the state dependent queuing models to the design of the facilities and the effect of pedestrian personal capacity on the design and the traffic congestion are discussed. The study does not validate the sustainability of adaptation of Western design codes for the pedestrian facilities in the countries like Bangladesh.

Matched MeSH terms: Crowding
Fulltext Directionally-Enhanced Binary Multi-Objective Particle Swarm Optimisation for Load Balancing in Software Defined Networks

Albowarab MH, Zakaria NA, Zainal Abidin Z

Sensors (Basel), 2021 May 12;21(10).
PMID: 34065920 DOI: 10.3390/s21103356

Various aspects of task execution load balancing of Internet of Things (IoTs) networks can be optimised using intelligent algorithms provided by software-defined networking (SDN). These load balancing aspects include makespan, energy consumption, and execution cost. While past studies have evaluated load balancing from one or two aspects, none has explored the possibility of simultaneously optimising all aspects, namely, reliability, energy, cost, and execution time. For the purposes of load balancing, implementing multi-objective optimisation (MOO) based on meta-heuristic searching algorithms requires assurances that the solution space will be thoroughly explored. Optimising load balancing provides not only decision makers with optimised solutions but a rich set of candidate solutions to choose from. Therefore, the purposes of this study were (1) to propose a joint mathematical formulation to solve load balancing challenges in cloud computing and (2) to propose two multi-objective particle swarm optimisation (MP) models; distance angle multi-objective particle swarm optimization (DAMP) and angle multi-objective particle swarm optimization (AMP). Unlike existing models that only use crowding distance as a criterion for solution selection, our MP models probabilistically combine both crowding distance and crowding angle. More specifically, we only selected solutions that had more than a 0.5 probability of higher crowding distance and higher angular distribution. In addition, binary variants of the approaches were generated based on transfer function, and they were denoted by binary DAMP (BDAMP) and binary AMP (BAMP). After using MOO mathematical functions to compare our models, BDAMP and BAMP, with state of the standard models, BMP, BDMP and BPSO, they were tested using the proposed load balancing model. Both tests proved that our DAMP and AMP models were far superior to the state of the art standard models, MP, crowding distance multi-objective particle swarm optimisation (DMP), and PSO. Therefore, this study enables the incorporation of meta-heuristic in the management layer of cloud networks.

Matched MeSH terms: Crowding
Fulltext Estimating direct and spill-over impacts of political elections on COVID-19 transmission using synthetic control methods

Lim JT, Maung K, Tan ST, Ong SE, Lim JM, Koo JR, et al.

PLoS Comput Biol, 2021 May;17(5):e1008959.
PMID: 34043622 DOI: 10.1371/journal.pcbi.1008959

Mass gathering events have been identified as high-risk environments for community transmission of coronavirus disease 2019 (COVID-19). Empirical estimates of their direct and spill-over effects however remain challenging to identify. In this study, we propose the use of a novel synthetic control framework to obtain causal estimates for direct and spill-over impacts of these events. The Sabah state elections in Malaysia were used as an example for our proposed methodology and we investigate the event's spatial and temporal impacts on COVID-19 transmission. Results indicate an estimated (i) 70.0% of COVID-19 case counts within Sabah post-state election were attributable to the election's direct effect; (ii) 64.4% of COVID-19 cases in the rest of Malaysia post-state election were attributable to the election's spill-over effects. Sensitivity analysis was further conducted by examining epidemiological pre-trends, surveillance efforts, varying synthetic control matching characteristics and spill-over specifications. We demonstrate that our estimates are not due to pre-existing epidemiological trends, surveillance efforts, and/or preventive policies. These estimates highlight the potential of mass gatherings in one region to spill-over into an outbreak of national scale. Relaxations of mass gathering restrictions must therefore be carefully considered, even in the context of low community transmission and enforcement of safe distancing guidelines.

Matched MeSH terms: Crowding
Modelling the Impact of Different Tuberculosis Control Interventions on the Prevalence of Tuberculosis in an Overcrowded Prison

Naning H, Al-Darraji HAA, McDonald S, Ismail NA, Kamarulzaman A

Asia Pac J Public Health, 2018 04;30(3):235-243.
PMID: 29502429 DOI: 10.1177/1010539518757229

The aim of this study was to simulate the effects of tuberculosis (TB) treatment strategies interventions in an overcrowded and poorly ventilated prison with both high (5 months) and low (3 years) turnover of inmates against improved environmental conditions. We used a deterministic transmission model to simulate the effects of treatment of latent TB infection and active TB, or the combination of both treatment strategies. Without any intervention, the TB prevalence is estimated to increase to 8.8% for a prison with low turnover of inmates but modestly stabilize at 5.8% for high-turnover prisons in a 10-year period. Reducing overcrowding from 6 to 4 inmates per housing cell and increasing the ventilation rate from 2 to 12 air changes per hour combined with any treatment strategy would further reduce the TB prevalence to as low as 0.98% for a prison with low inmate turnover.

Matched MeSH terms: Crowding*
Fulltext Physical distancing and risk of COVID-19 in small-scale fisheries: a remote sensing assessment in coastal Ghana

Okyere I, Chuku EO, Ekumah B, Angnuureng DB, Boakye-Appiah JK, Mills DJ, et al.

Sci Rep, 2020 12 29;10(1):22407.
PMID: 33376254 DOI: 10.1038/s41598-020-79898-4

The novel coronavirus is predicted to have dire implications on global food systems including fisheries value chains due to restrictions imposed on human movements in many countries. In Ghana, food production, both agriculture and fisheries, is exempted from restrictions as an essential service. The enforcement of COVID-19 prevention protocols, particularly social distancing, has been widely reported in Ghana's agricultural markets whereas casual observations and media reports on fish landing sites suggest no such enforcements are in place. This study aimed to provide sound scientific evidence as a basis for informed policy direction and intervention for the artisanal fishing sector in these challenging times. We employed an unmanned aerial vehicle in assessing the risk of artisanal fishers to the pandemic using physical distancing as a proxy. From analysis of cumulative distribution function (G-function) of the nearest-neighbour distances, this study underscored crowding at all surveyed fish landing beaches, and identified potential "hotspots" for disease transmission. Aerial measurements taken at times of peak landing beach activity indicated that the highest proportion of people, representing 56%, 48%, 39% and 78% in Elmina, Winneba, Apam and Mumford respectively, were located at distances of less than one metre from their nearest neighbour. Risk of crowding was independent of the population at the landing beaches, suggesting that all categories of fish landing sites along the coast would require equal urgency and measured attention towards preventing and mitigating the spread of the disease.

Matched MeSH terms: Crowding
Can dental home visits really reduce caries incidence in pre-school children?

Baughan S, Rodd H

Evid Based Dent, 2022 06;23(2):64-65.
PMID: 35750730 DOI: 10.1038/s41432-022-0268-5

Design This was a non-blinded multiple-site randomised controlled clinical trial.Case selection Children, aged 5-6 years, were recruited from 11 government-funded kindergartens (pre-schools) in Selangor, Malaysia. The kindergartens were randomly allocated to either the Intervention Group (n = 185 children) or the Control Group (n = 142 children). A clinical examination was conducted to determine the participants' baseline caries experience. Over a 24-month period (commencing in 2015), the Intervention Group received six -monthly dental home visits (DHVs) to provide the families with oral hygiene and dietary instruction, along with educational leaflets. The Control Group received only the educational leaflets. Caries incidence was measured in terms of both the proportion of children who developed new carious lesions, and the number of primary molars in which new carious lesions were seen at 24 months.Data analysis A chi-squared test was used to compare baseline socioeconomic characteristics as well as the proportion of children in each arm who developed new carious lesions. A t-test was used to compare the mean number of primary molars that developed new caries in each group. In addition, the number needed to treat (NNT) was determined.Results There was a 70% (n = 132) and 71% (n = 100) completion rate for participants in the Intervention and Control Groups, respectively. At 24 months, the key finding was that significantly fewer children in the Intervention Group (14.4%; n = 19) had developed new caries lesions compared to the Control Group (60%; n = 60) (p = 0.001). The NNT was calculated as 2.2, to prevent new caries in one child. After controlling for parental education level and household crowding, children in the Control Group were 8.2 times more likely to develop caries in their primary molars than those in the Intervention Group.Conclusions The authors concluded that in a middle-income country such as Malaysia, six -monthly dental home visits are an effective caries prevention strategy for children aged 5-6 years old from low-income families.

Matched MeSH terms: Crowding
Social problems and health in urbanization

Talib R, Agus MR

Southeast Asian J. Trop. Med. Public Health, 1992;23 Suppl 3:84-93.
PMID: 1342763

One of the main characteristics of urbanization in Asia is the very rapid increase in population movement from rural to urban centers. This phenomenon has led to changing population structure, its composition and lifestyles in the cities and its fringes. As a consequent of population pressure on urban system and infrastructure, compounded by the nature of the composition of the in-migrant population, the urban concentrates are faced with several social and socio-economic problems. Although there has been a lot of interests among researchers to study the causes and effects or urbanization, there is a vacuum in the area of health implications. Planners and administrators usually give priority to the physical aspects of the urban and urbanities. Social problems and health implications thereof receives very little attention either at the level of administration or research. This paper therefore is a brave attempt to focus and draw some attention to this neglected area by looking at selected social problems and the health consequences.

Matched MeSH terms: Crowding
Fulltext High frequency of Haemophilus influenzae associated with respiratory tract infections among Malaysian Hajj pilgrims

Nik Zuraina NMN, Sarimah A, Suharni M, Hasan H, Suraiya S

J Infect Public Health, 2018 08 07;11(6):878-883.
PMID: 30097415 DOI: 10.1016/j.jiph.2018.07.010

BACKGROUND: Overcrowding during the annual Hajj pilgrimage has been known to increase the risk of infectious diseases transmission. Despite the high prevalence of respiratory illness among Malaysian Hajj pilgrims, knowledge about the etiologic pathogens is yet very limited. Thus, this study aimed to determine the spectrum of bacterial respiratory pathogens among the Hajj pilgrims returning to Malaysia in year 2016.
METHODS: Expectorated sputum specimens were collected from the Hajj pilgrims with symptomatic respiratory tract infections (RTIs). Subsequently, the bacterial pathogens were identified using the standard bacteriological culture method and Vitek II system.
RESULTS: This study indicated that 255 (87.33%) out of 292 cultured sputa were positive with at least one potential pathogenic bacteria. Out of 345 total bacterial isolates, 60% (n=207) were Haemophilus influenzae, which was associated with both single bacterium infection (132/173, 76.3%) and multiple bacterial infections (75/82, 91.5%). The other bacterial isolates included; Klebsiella pneumoniae (n=37, 10.7%), Moraxella catarrhalis (n=27, 7.8%), Haemophilus parainfluenzae (n=25, 7.2%), Streptococcus group G (n=18, 5.2%), Klebsiella spesies (n=16, 4.6%), Streptococcus pneumoniae (n=11, 3.2%) and few other organisms.
CONCLUSION: High frequency of H. influenzae was isolated from Malaysian Hajj pilgrims, especially those with respiratory symptoms. Further study should evaluate the actual pathogenicity of the organism and the interactions between the respiratory microbiota towards developing effective prevention strategies of RTIs among the local pilgrims.

Matched MeSH terms: Crowding
Tualang honey supplement improves memory performance and hippocampal morphology in stressed ovariectomized rats

Al-Rahbi B, Zakaria R, Othman Z, Hassan A, Mohd Ismail ZI, Muthuraju S

Acta Histochem, 2014 Jan;116(1):79-88.
PMID: 23810156 DOI: 10.1016/j.acthis.2013.05.004

Recently, our research team has reported that Tualang honey was able to improve immediate memory in postmenopausal women comparable with that of estrogen progestin therapy. Therefore the aim of the present study was to examine the effects of Tualang honey supplement on hippocampal morphology and memory performance in ovariectomized (OVX) rats exposed to social instability stress. Female Sprague-Dawley rats were divided into six groups: (i) sham-operated controls, (ii) stressed sham-operated controls, (iii) OVX rats, (iv) stressed OVX rats, (v) stressed OVX rats treated with 17β-estradiol (E2), and (vi) stressed OVX rats treated with Tualang honey. These rats were subjected to social instability stress procedure followed by novel object recognition (NOR) test. Right brain hemispheres were subjected to Nissl staining. The number and arrangement of pyramidal neurons in regions of CA1, CA2, CA3 and the dentate gyrus (DG) were recorded. Two-way ANOVA analyses showed significant interactions between stress and OVX in both STM and LTM test as well as number of Nissl-positive cells in all hippocampal regions. Both E2 and Tualang honey treatments improved both short-term and long-term memory and enhanced the neuronal proliferation of hippocampal CA2, CA3 and DG regions compared to that of untreated stressed OVX rats.

Matched MeSH terms: Crowding

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