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Displaying publications 101 - 120 of 735 in total

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Solid waste bin detection and classification using Dynamic Time Warping and MLP classifier

Islam MS, Hannan MA, Basri H, Hussain A, Arebey M

Waste Manag, 2014 Feb;34(2):281-90.
PMID: 24238802 DOI: 10.1016/j.wasman.2013.10.030

The increasing requirement for Solid Waste Management (SWM) has become a significant challenge for municipal authorities. A number of integrated systems and methods have introduced to overcome this challenge. Many researchers have aimed to develop an ideal SWM system, including approaches involving software-based routing, Geographic Information Systems (GIS), Radio-frequency Identification (RFID), or sensor intelligent bins. Image processing solutions for the Solid Waste (SW) collection have also been developed; however, during capturing the bin image, it is challenging to position the camera for getting a bin area centralized image. As yet, there is no ideal system which can correctly estimate the amount of SW. This paper briefly discusses an efficient image processing solution to overcome these problems. Dynamic Time Warping (DTW) was used for detecting and cropping the bin area and Gabor wavelet (GW) was introduced for feature extraction of the waste bin image. Image features were used to train the classifier. A Multi-Layer Perceptron (MLP) classifier was used to classify the waste bin level and estimate the amount of waste inside the bin. The area under the Receiver Operating Characteristic (ROC) curves was used to statistically evaluate classifier performance. The results of this developed system are comparable to previous image processing based system. The system demonstration using DTW with GW for feature extraction and an MLP classifier led to promising results with respect to the accuracy of waste level estimation (98.50%). The application can be used to optimize the routing of waste collection based on the estimated bin level.

Matched MeSH terms: Models, Theoretical*
Socio-economic determinants of fertility in some countries of Asia

Pathak KB, Murty PK

Artha Vijnana, 1982 Jun;24(2):163-78.
PMID: 12339046
Matched MeSH terms: Models, Theoretical*
Fulltext Social embeddedness as a mechanism for linking social cohesion to well-being among older adults: moderating effect of gender

Momtaz YA, Haron SA, Ibrahim R, Hamid TA

Clin Interv Aging, 2014;9:863-70.
PMID: 24904206 DOI: 10.2147/CIA.S62205

BACKGROUND: The positive effect of social cohesion on well-being in older adults has been well documented. However, relatively few studies have attempted to understand the mechanisms by which social cohesion influences well-being. The main aim of the current study is to identify social pathways in which social cohesion may contribute to well-being.
METHODS: The data for this study (taken from 1,880 older adults, aged 60 years and older) were drawn from a national survey conducted during 2008-2009. The survey employed a two-stage stratified sampling process for data collection. Structural equation modeling was used to test mediating and moderating analyses.
RESULTS: The proposed model documented a good fit to the data (GFI =98; CFI =0.99; RMSEA =0.04). The findings from bootstrap analysis and the Sobel test revealed that the impact of social cohesion on well-being is significantly mediated by social embeddedness (Z=5.62; P<0.001). Finally, the results of a multigroup analysis test showed that social cohesion influences well-being through the social embeddedness mechanism somewhat differently for older men than women.
CONCLUSION: The findings of this study, in addition to supporting the importance of neighborhood social cohesion for the well-being of older adults, also provide evidence that the impact of social cohesion towards well-being is mediated through the mechanism of social embeddedness.

Matched MeSH terms: Models, Theoretical
Skin colour detection based on an adaptive multi thresholding technique

Ahmed M. Mbarib, Mohammad Hamiruce Marhaban, Abdul Rahman Ramli

Pertanika Journal of Science & Technology, 2007;15(2):103-111.
MyJurnal

Skin colour is an important visual cue for face detection, face recogmtlon, hand segmentation for gesture analysis and filtering of objectionable images. In this paper, the adaptive skin color detection model is proposed, based on two bivariate normal distribution models of the skin chromatic subspace, and on image segmentation using an automatic and adaptive multi-thresholding technique. Experimental results on images presenting a wide range of variations in lighting condition and background demonstrate the efficiency of the proposed skin-segmentation algorithm.

Matched MeSH terms: Models, Theoretical
Fulltext Single-event-upset sensitivity analysis on low-swing drivers

Mahyuddin NM, Russell G

ScientificWorldJournal, 2014;2014:876435.
PMID: 24782671 DOI: 10.1155/2014/876435

Technology scaling relies on reduced nodal capacitances and lower voltages in order to improve performance and power consumption, resulting in significant increase in layout density, thus making these submicron technologies more susceptible to soft errors. Previous analysis indicates a significant improvement in SEU tolerance of the driver when the bias current is injected into the circuit but results in increase of power dissipation. Subsequently, other alternatives are considered. The impact of transistor sizes and temperature on SEU tolerance is tested. Results indicate no significant changes in Q(crit) when the effective transistor length is increased by 10%, but there is an improvement when high temperature and high bias currents are applied. However, this is due to other process parameters that are temperature dependent, which contribute to the sharp increase in Q(crit). It is found that, with temperature, there is no clear factor that can justify the direct impact of temperature on the SEU tolerance. Thus, in order to improve the SEU tolerance, high bias currents are still considered to be the most effective method in improving the SEU sensitivity. However, good trade-off is required for the low-swing driver in order to meet the reliability target with minimal power overhead.

Matched MeSH terms: Models, Theoretical*
Fulltext Simultaneous time-temperature-thickness superposition theoretical and statistical modelling of convective drying of guava

Kek SP, Chin NL, Yusof YA

J Food Sci Technol, 2014 Dec;51(12):3609-22.
PMID: 25477628 DOI: 10.1007/s13197-013-0923-0

Modelling studies of guava drying and quality are presented using theoretical and statistical models by varying temperature from 55 to 75 °C and slice thickness from 3 to 9 mm. The quality of dried fruit was measured for its water activity, colour, vitamin C, and texture. The superposition technique with Midilli-Kucuk model showed efficiency in modelling the drying process with R (2) = 0.9991. The second-order polynomial equations adequately described the quality of dried guava with regression coefficient, R (2) > 0.7. Drying time was a good function of temperature and thickness (P

Matched MeSH terms: Models, Theoretical
Fulltext Simulation of spray drying on Piper betle Linn extracts using computational fluid dynamics

Cher Pin, S., Rashmi, W., Khalid, M., Chong, C.H., Woo, M.W., Tee, L.H.

International Food Research Journal, 2014;21(3):1089-1096.
MyJurnal

The drying of Piper betle Linn (betel) leaf extract using a lab scale spray dryer was simulated using Computational Fluid Dynamics (CFD). Three different turbulent models (standard k-ε, RNG k-ε and realizable k-ε) were used in the present study to determine the most suitable model for predicting the flow profile. Parametric studies were also conducted to evaluate the effect of process variables on the final moisture content. Four different initial droplet sizes (36, 79, 123 and 166 μm) were tested with four sets of combination of hot air temperature (140 and 160°C) and feed rate (4, 9.5 and 15 ml/min). It was found that standard k-ε is the most suitable turbulent model to predict the flow behaviour Moreover, the lowest final moisture content present in samples was obtained at 140°C and a feed rate of 15.0 ml/min.

Matched MeSH terms: Models, Theoretical
Simulation of left ventricle flow dynamics with dilated cardiomyopathy during the filling phase

Chan BT, Ong CW, Lim E, Abu Osman NA, Al Abed A, Lovell NH, et al.

Annu Int Conf IEEE Eng Med Biol Soc, 2012;2012:6289-92.
PMID: 23367367 DOI: 10.1109/EMBC.2012.6347432

Dilated cardiomyopathy (DCM) is a common cardiac disease which leads to the deterioration in cardiac performance. A computational fluid dynamics (CFD) approach can be used to enhance our understanding of the disease, by providing us with a detailed map of the intraventricular flow and pressure distributions. In the present work, effect of ventricular size on the intraventricular flow dynamics and intraventricular pressure gradients (IVPGs) was studied using two different implementation methods, i.e. the geometry-prescribed and the fluid structure interaction (FSI) methods. Results showed that vortex strength and IVPGs are significantly reduced in a dilated heart, leading to an increased risk of thrombus formation and impaired ventricular filling. We suggest FSI method as the ultimate method in studying ventricular dysfunction as it provides additional cardiac disease prognostic factors and more realistic model implementation.

Matched MeSH terms: Models, Theoretical
Simulation of Rainfall-Runoff Response in Ecological Swale with On-Line Subsurface Detention Using Infoworks SD

Ghadim HB, Hin LS

Water Environ Res, 2017 Sep 01;89(9):862-870.
PMID: 28855022 DOI: 10.2175/106143017X14902968254764

The Bio-Ecological Drainage System (BIOECODS) is a sustainable drainage (SUDS) to demonstrate the 'control at source' approaches for urban stormwater management in Malaysia. It is an environmentally friendly drainage system that was designed to increase infiltration, reduce peak flow at outlet, improve water quality, through different BMPs, such as grass swale, retention pond, etc. A special feature of BIOECODS is ecological swale with on-line subsurface detention. This study attempted to create a model of ecological swale with on-line subsurface conveyance system with InfoWorks SD. The new technique has been used Storm Water Management Model (SWMM) model to describe overland flow routing and Soil Conservation Service Method (SCS) used to model infiltration or subsurface flow. The modeling technique has been proven successful, as the predicted and observed closely match each other, with a mean error of 4.58 to 7.32%. The calibrated model then used to determine the ratio of the flow exchange between the surface and subsurface drainage system. Results from the model showed that the runoff ratio exchange between the surface and subsurface is 60 to 90%.

Matched MeSH terms: Models, Theoretical
Sickle-cell trait in human biological and cultural evolution. Development of agriculture causing increased malaria is bound to gene-pool changes causing malaria reduction

Wiesenfeld SL

Science, 1967 Sep 08;157(3793):1134-40.
PMID: 6038684

The particular agricultural adaptation we have been considering is the ultimate determinant of the presence of malaria parasites in the intracellular environment of the human red blood cell. This change in the cellular environment is deleterious for normal individuals, but individuals with the sickle-cell gene are capable of changing their red-cell environment so that intense parasitism never develops. Normal individuals suffer higher mortality rates and lower fertility rates in a malarious environment than individuals with the sickle-cell trait do, so the latter contribute proportionately more people to succeeding generations.

Matched MeSH terms: Models, Theoretical
Fulltext Shear Capacity of C-Shaped and L-Shaped Angle Shear Connectors

Tahmasbi F, Maleki S, Shariati M, Ramli Sulong NH, Tahir MM

PLoS One, 2016;11(8):e0156989.
PMID: 27478894 DOI: 10.1371/journal.pone.0156989

This paper investigates the behaviour of C-shaped and L-shaped angle shear connectors embedded in solid concrete slabs. An effective finite element model is proposed to simulate the push out tests of these shear connectors that encompass nonlinear material behaviour, large displacement and damage plasticity. The finite element models are validated against test results. Parametric studies using this nonlinear model are performed to investigate the variations in concrete strength and connector dimensions. The finite element analyses also confirm the test results that increasing the length of shear connector increases their shear strength proportionately. It is observed that the maximum stress in L-shaped angle connectors takes place in the weld attachment to the beam, whereas in the C-shaped angle connectors, it is in the attached leg. The location of maximum concrete compressive damage is rendered in each case. Finally, a new equation for prediction of the shear capacity of C-shaped angle connectors is proposed.

Matched MeSH terms: Models, Theoretical*
Sewage sludge composting simulation as carbon/nitrogen concentration change

Kabbashi N

J Environ Sci (China), 2011;23(11):1925-8.
PMID: 22432320

Available composting models do not describe accurately the dynamics of composting processes. Difficulty in modeling composting processes is attributed mainly to the unpredicted change in process rate caused by change in activation energy value (E). This article presented the results of an attempt made to utilize patterns of change in carbon, nitrogen and temperature profiles to model sewage sludge composting process as a multi-stage process. Results of controlled sewage sludge composting experiments were used in the study. All the experiments were carried out as batch experiments in a 300-liter Horizontal Drum Bioreactor (HDB). Analysis of the profiles of carbon, nitrogen and temperature has indicated that there were clear patterns that could be used to develop simple models of the process, the initial C/N ratio was between 7-8 and the final C/N ratio of the compost in most experiments were found to be around 15.0, indicating the compost was fully matured and could be used safely for agricultural purpose. Electrical conductivity of composting material decreased from 1.83 to 1.67 dS/m, after a period, it increased gradually from 2.01 to 2.23 dS/m and remained at around 2.33 dS/m till the end of composting. It is found that change in the concentration of total carbon can reasonably be described by three constant process rate coefficients (k1, k2, k3). It is found that the process starts with a certain process rate coefficient (k1) and continues until peak temperature is reached, then it reaches lower process (k2) in the declining phase of the thermophilic stage, and finally it proceeds with a faster process rate (k3) when maturation is reached. Change in the concentration of total nitrogen has shown to have the same patterns of change as carbon.

Matched MeSH terms: Models, Theoretical*
Service quality in health care setting

Rashid WE, Jusoff HK

Int J Health Care Qual Assur, 2009;22(5):471-82.
PMID: 19725368

This paper attempts to explore the concept of service quality in a health care setting.

Matched MeSH terms: Models, Theoretical
Fulltext Sequential Insertion Heuristic with Adaptive Bee Colony Optimisation Algorithm for Vehicle Routing Problem with Time Windows

Jawarneh S, Abdullah S

PLoS One, 2015;10(7):e0130224.
PMID: 26132158 DOI: 10.1371/journal.pone.0130224

This paper presents a bee colony optimisation (BCO) algorithm to tackle the vehicle routing problem with time window (VRPTW). The VRPTW involves recovering an ideal set of routes for a fleet of vehicles serving a defined number of customers. The BCO algorithm is a population-based algorithm that mimics the social communication patterns of honeybees in solving problems. The performance of the BCO algorithm is dependent on its parameters, so the online (self-adaptive) parameter tuning strategy is used to improve its effectiveness and robustness. Compared with the basic BCO, the adaptive BCO performs better. Diversification is crucial to the performance of the population-based algorithm, but the initial population in the BCO algorithm is generated using a greedy heuristic, which has insufficient diversification. Therefore the ways in which the sequential insertion heuristic (SIH) for the initial population drives the population toward improved solutions are examined. Experimental comparisons indicate that the proposed adaptive BCO-SIH algorithm works well across all instances and is able to obtain 11 best results in comparison with the best-known results in the literature when tested on Solomon's 56 VRPTW 100 customer instances. Also, a statistical test shows that there is a significant difference between the results.

Matched MeSH terms: Models, Theoretical*
Fulltext Sensing study of quinoxaline analogues with theoretical calculation, single-crystal X-ray structure and real application in commercial fruit juices

Chakraborty S, Goswami S, Quah CK, Pakhira B

R Soc Open Sci, 2018 Jun;5(6):180149.
PMID: 30110468 DOI: 10.1098/rsos.180149

Single-crystal X-ray structures of dimeric quinoxaline aldehyde (QA), quinoxaline dihydrazone (DHQ) and HQNM (Goswami S et al. 2013 Tetrahedron Lett.54, 5075-5077. (doi:10.1016/j.tetlet.2013.07.051); Goswami S et al. 2014 RSC Adv.4, 20 922-20 926. (doi:10.1039/C4RA00594E); Goswami S et al. 2014 New J. Chem.38, 6230-6235. (doi:10.1039/C4NJ01498G)) are reported along with the theoretical study. Among them, QA is not acting as an active probe, but DHQ and HQNM are serving as selective and sensitive probe for the Fe3+ cation and the Ni2+ cation, respectively. DHQ can also detect the Fe3+ in commercial fruit juices (grape and pomegranate).

Matched MeSH terms: Models, Theoretical
Fulltext Seluge++: a secure over-the-air programming scheme in wireless sensor networks

Doroodgar F, Abdur Razzaque M, Isnin IF

Sensors (Basel), 2014;14(3):5004-40.
PMID: 24618781 DOI: 10.3390/s140305004

Over-the-air dissemination of code updates in wireless sensor networks have been researchers' point of interest in the last few years, and, more importantly, security challenges toward the remote propagation of code updating have occupied the majority of efforts in this context. Many security models have been proposed to establish a balance between the energy consumption and security strength, having their concentration on the constrained nature of wireless sensor network (WSN) nodes. For authentication purposes, most of them have used a Merkle hash tree to avoid using multiple public cryptography operations. These models mostly have assumed an environment in which security has to be at a standard level. Therefore, they have not investigated the tree structure for mission-critical situations in which security has to be at the maximum possible level (e.g., military applications, healthcare). Considering this, we investigate existing security models used in over-the-air dissemination of code updates for possible vulnerabilities, and then, we provide a set of countermeasures, correspondingly named Security Model Requirements. Based on the investigation, we concentrate on Seluge, one of the existing over-the-air programming schemes, and we propose an improved version of it, named Seluge++, which complies with the Security Model Requirements and replaces the use of the inefficient Merkle tree with a novel method. Analytical and simulation results show the improvements in Seluge++ compared to Seluge.

Matched MeSH terms: Models, Theoretical
Fulltext Self care interventions to advance health and wellbeing: a conceptual framework to inform normative guidance

Narasimhan M, Allotey P, Hardon A

BMJ, 2019 Apr 01;365:l688.
PMID: 30936087 DOI: 10.1136/bmj.l688

Manjulaa Narasimhan and colleagues argue that there is a pressing need for a clearer conceptualisation of self care to support health policy

Matched MeSH terms: Models, Theoretical*
Fulltext Seismic response of a light rail transit station equipped with braced viscous damper

Fateh, A., Hejazi, F., Ramanathan, R.A., Jaffar, M.S.

Pertanika Journal of Science & Technology, 2016;24(2):273-283.
MyJurnal

The use of the Light Rail Transit (LRT) system is currently preferred because LRT is sustainable,
improves travel options and facilitates swift mobility in urban areas. Hence, the structural stability
and safety of this public transportation system against seismic occurrences are indispensable. Given
that these structures cannot be considered conventional frames because of their complex architectural
design, focussing meticulously on reliable seismic design codes and structural rehabilitation techniques
is vital for the design of the lateral resistance system. One Malaysian LRT station is considered in this
study, and the seismic response of this train station when equipped with supplementary viscous damper
devices is evaluated. Thus, the LRT station is modelled through finite element simulation. The methods
of seismic analysis are limited to linear seismic analyses, namely, response spectrum and time history
analyses. Results derived in this study show a significant improvement in structural response when the
station is fitted with dampers; approximately 40% reduction in displacement is observed at the top joint
of the roof. Furthermore, the lateral base shears decrease by approximately 70%.

Matched MeSH terms: Models, Theoretical
Security robot for the prevention of workplace violence using the Non-linear Adaptive Heuristic Mathematical Model

Tao H, Rahman MA, Al-Saffar A, Zhang R, Salih SQ, Zain JM, et al.

Work, 2021;68(3):853-861.
PMID: 33612528 DOI: 10.3233/WOR-203419

BACKGROUND: Nowadays, workplace violence is found to be a mental health hazard and considered a crucial topic. The collaboration between robots and humans is increasing with the growth of Industry 4.0. Therefore, the first problem that must be solved is human-machine security. Ensuring the safety of human beings is one of the main aspects of human-robotic interaction. This is not just about preventing collisions within a shared space among human beings and robots; it includes all possible means of harm for an individual, from physical contact to unpleasant or dangerous psychological effects.
OBJECTIVE: In this paper, Non-linear Adaptive Heuristic Mathematical Model (NAHMM) has been proposed for the prevention of workplace violence using security Human-Robot Collaboration (HRC). Human-Robot Collaboration (HRC) is an area of research with a wide range of up-demands, future scenarios, and potential economic influence. HRC is an interdisciplinary field of research that encompasses cognitive sciences, classical robotics, and psychology.
RESULTS: The robot can thus make the optimal decision between actions that expose its capabilities to the human being and take the best steps given the knowledge that is currently available to the human being. Further, the ideal policy can be measured carefully under certain observability assumptions.
CONCLUSION: The system is shown on a collaborative robot and is compared to a state of the art security system. The device is experimentally demonstrated. The new system is being evaluated qualitatively and quantitatively.

Matched MeSH terms: Models, Theoretical
Scopolamine, a Toxin-Induced Experimental Model, Used for Research in Alzheimer's Disease

Chen WN, Yeong KY

CNS Neurol Disord Drug Targets, 2020;19(2):85-93.
PMID: 32056532 DOI: 10.2174/1871527319666200214104331

Scopolamine as a drug is often used to treat motion sickness. Derivatives of scopolamine have also found applications as antispasmodic drugs among others. In neuroscience-related research, it is often used to induce cognitive disorders in experimental models as it readily permeates the bloodbrain barrier. In the context of Alzheimer's disease, its effects include causing cholinergic dysfunction and increasing amyloid-β deposition, both of which are hallmarks of the disease. Hence, the application of scopolamine in Alzheimer's disease research is proven pivotal but seldom discussed. In this review, the relationship between scopolamine and Alzheimer's disease will be delineated through an overall effect of scopolamine administration and its specific mechanisms of action, discussing mainly its influences on cholinergic function and amyloid cascade. The validity of scopolamine as a model of cognitive impairment or neurotoxin model will also be discussed in terms of advantages and limitations with future insights.

Matched MeSH terms: Models, Theoretical

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