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Deep learning model for prediction of progressive mild cognitive impairment to Alzheimer's disease using structural MRI / Lim Bing Yan
No full textAlzheimer’s disease (AD), an irreversible neurodegenerative disorder that has caused the majority cases of dementia, wherein patients suffer progressive memory loss and cognitive function decline. Despite having no drugs for curing, early detection of AD allows the provision of preventive treatment to control the disease progression. The objective of this project is to develop a computer-aided system based on deep learning model to identify AD from cognitively normal and its early stage, mild cognitive impairment (MCI), using only structural MRI (sMRI). In this project, multiclass classification was applied. The dataset consisted of 3D T1-weighted brain sMRI images from the ADNI database containing 819 participants. A series of pre-processing methods were applied to the dataset; For example, skull stripping, bias field correction, pixel values normalisation, and data augmentation. HMRF tissue classifier was used to segment the brain MRI into 3 separate regions of grey matter, white matter, and cerebrospinal fluid. Axial brain images were extracted from the 3D MRI and being fed as input to the convolutional neural network (CNN) to perform multiclass classification of AD-CN-MCI. 3 different models were being experimented namely a CNN from scratch, VGG-16, and ResNet-50. The convolutional base of VGG-16 and ResNet-50 trained on ImageNet dataset were used as a feature extractor. Additionally, a new densely connected classifier was added on top of the convolutional base for performing classification. Using the 20% held out testing data, the performance of each model was reported and discussed. Among the 3 models, VGG-16 achieved the best testing performance with accuracy of 78.57%, precision of 73.94%, recall of 81.37%, and F1-score of 77.48%. Transfer learning technique allowed VGG-16 to achieve better performance despite a small number of data was being used. However, the best-performed VGG-16 has performed below average in comparison to previous works. Hence, limitations and possible solutions were outlined for future improvement
Mitigation of airborne contaminants in Malaysian offices / Jaspreet Kaur Malkeet Singh
Get PDFAirborne contamination has been in the talk throughout the years. Research studies have shown that due to airborne contaminations such as volatile organic compound, particulate matter, asbestos, radon, nitrogen oxides, viruses, and ozone in office there is possible effects of indoor air quality (IAQ) on the office building and its work performance. The COVID-19 pandemic has promoted a renewed interest in the assessment of decline IAQ condition in closed space office. According to World Health Organization (WHO), it has been proven that one of the transmission routes of COVID-19 is through aerosols which open a possibility that an airborne transmission can occur, thus, higher chance of spreading in an indoor space with high occupancy, such as office building.
Thus, the study aims to develop a comprehensive checklist and guideline that is used to mitigate and prevent airborne contamination in office. As a result, a survey was conducted to determine the source of contaminant in office and its health impact on office occupants. Questionnaire forms were distributed among the office occupants to get their feedback on their satisfaction towards their office IAQ. A total of 102 office occupants have participated in this survey. The data collected were analysed using SPSS statistical software and based on the data analysed, most of the respondent experience sick building syndrome (SBS) symptoms analysed through four factor which are source of contamination in office, offices surrounding environment, office equipment and activities and ventilation.
Hence, based on the results. a checklist and guideline were developed to prevent or minimize indoor air contamination in office. This checklist and guideline were as a safety measure for office users, owner, employer, and employee to evaluate and mitigate the source of airborne contamination in closed space office. The checklist aims to identify the factors influencing the complaints, thus giving a general overview of the suspected source of pollutants and the guideline aims to provide awareness and steps to be taken to mitigate and reduce the presence of source of contaminant in the office. A total of nineteen new parameter were added in the checklist which are ventilation system, type of material, cleaning material, food and drink management, smoking management, waste management, toilet management, furniture, electronic equipment, office stationaries, personal and hygiene product, surrounding activities, maintenance operation include pest control, refreshers, office design, storage management, natural occurrence, plant-based contamination, and air conditioning system
Design and simulation of wireless power transfer using capacitive technique / Nur Fatin Afiqah Ahmad
Get PDFThe development of wireless power transfer technology in various applications has getting widely nowadays. Wireless energy can be transferred by inductive power transfer (IPT) through electric field and capacitive power transfer (CPT) through magnetic field. Most of the applications has been utilized the technology of IPT for transfering power wirelessly, but in this project, a new method of CPT will be used for the purposed of biomedical implantable application which is implantable pulse generator (IPG). In terms of biomedical implantable application, CPT has some extra advantages compared to the traditional method of IPT such as the circuit structured will be more simple and convenient as the receiver circuit for this application will be implanted inside of the human body. Besides, the main reasons to use CPT technique are CPT has low electromagnetic interference (EMI), power losses is low and the ability of CPT to transfer power across metal barriers. In this project, the CPT technique has been applied through class E inverter circuit. A 12V DC source has been supplied to the inverter circuit that will operate at 1 MHz frequency to deliver 2 Watt of power to the load. The effects of higher load resistance values will be analyzed through the class E circuit system and the improvement of class E circuit by impedance matching will be applied. Overall, class E circuit is able to achieve ZVS waveform and efficiency of 95.38% by Matlab simulation for the resistance load value that have been designed theoretically. As the resistance value is set to some higher random values, class E circuit could only achieve ZVS and efficiency of more than 90% with the improvement by impedance matching circuit
Design and simulation of hybrid piezo-pyroelectric energy conversion device / Nurul Adina Azman
Get PDFSustainable energy had been eye as a huge opportunity to replace current fossil energy since it can be harvest in various forms. This study focusing on piezoelectric energy and pyroelectric energy which involves heating and vibration energy sources considering it is common phenomenon produce by numerous mechanical systems for example car engine and HVAC system. This study aims to design and simulate the performance of hybrid piezo-pyroelectric energy for low grade applications. The design of the hybrid piezo- pyroelectric conversion device is done by using SolidWorks. This study introduces performance of the device when different air heat temperature and force by air flow release from condenser is applied to the device. ANSYS is used for analytical calculation to compare the result with theoretical calculation. Both analytical and theoretical power output produce is compared. This study proved that force and heat temperature does affect the power output and voltage output of the device. From the results, it shows that analytical calculation value is higher than theoretical calculation for voltage output and total power output for both air heat temperature and force by air flows parameter. The result shows the tendency of air heat temperature produce higher voltage output and total power output than force by air flow release
Identification and analysis of human physical exercise postures using computer vision and deep learning / Sriram Krishnamoorthy
No full textThe ability of the human beings to perform physical exercise postures is identified by the unique ways and its important categories are gait analysis and muscle expansion of the human body as exercise performance. The postures performed by the human beings are estimated in a dynamic way. Most current systems which are employed for identifying human exercises propose complex systems. The advancement of the Artificial Intelligence broke the existing complexities, identifies, and analyze the human exercise without complex models. The effectiveness of the Computer Vision and Deep Learning are used to monitor the accurate exercise postures of every human gait to solve the trainer’s vacuum in the exercise environment. In this paper, it has evaluated and developed customized pose model to identify correct human physical postures, to analyze the correct form of physical exercise in a correct way in all type of exercise environments. For correct comparison, typical nodal points are identified (depends on exercise type) from the human body to calculate the estimations in a synchronous way. The estimations are nodal analysis which replicates the correct analyzation. The input frames of nodes are obtained by Webcam to a computer which makes the identification dynamic and naturalistic as Human-Computer interaction. We propose Deep pose estimation model to improve the analyzation of the physical exercises without complex systems. The results demonstrated the possibility of non-invasive identification which can be used for certain physical exercise postures using simple system with better accuracy
Correlating physiological responses of exergaming boxing in different body positions and disability / Nor Aina Mohd Jai
No full textPhysiological responses during exergaming may be affected by the position of gameplay and physical disability. This study aims to validate the correlations between heart rate and rating of perceived exertion coefficients when playing a moderate-vigorous intensity exergame among the able-bodied and wheelchair-user populations to formulate a possible regression model based on confounding factors, such as the position of gameplay, disability, age, or body mass index. To do this, the Sony PlayStation 3® consoles, along with its two Move motion controllers; Sony Eye Camera and Sports Champion 2® software, were selected as the modality of choice. A total of 45 participants were recruited and divided into able-bodied (mean age of 25.1 (2.95)) and wheelchair-user (mean age of 30.3 (10.3)). The able-bodied participants performed the Move Boxing in sitting position for 10 minutes and standing position for 10 minutes, with at least a day gap. Wheelchair-users performed the Move Boxing while seated in their wheelchairs for 10 minutes. HR measurements were obtained at rest and during gameplay. RPE was assessed using Borg’s modified (1−10) and original (6−20) scales. All data were expressed as mean (standard deviation) (SD). The significance level was set as a priority at P=0.05. SPSS (Version 25.0) was utilized to perform all statistical analyses. Normality tests and statistical tests were conducted, including paired-sample t-test, bivariate Pearson’s correlation, and Spearman’s rho correlation, to analyse the results. The mean HR was significantly higher when the able-bodied users performed exergaming in the standing position (130.79 (23.18) beats per minute (bpm)) compared to the sitting position (116.46 (19.08) bpm) (p ≤0.05), and more similar to those obtained by wheelchair-users while playing on their wheelchairs (130 (14) bpm). There was a significant correlation between HR and RPE values while playing boxing exergame
in the standing position. For wheelchair-users, HR elevation also correlated well with both Borg’s RPE original and modified scales during exergaming while being seated in their wheelchairs. A regression model that can be fitted into an equation to predict HR from reported RPE was derived from the significant values of Pearson’s correlation. The formula extracted from the linear regression models provided reliable predictions in estimating HR from reported RPE while boxing exergaming in a standing position and being seated in wheelchairs for future research works
Investigating the effect of khat (catha edulis) on selected obesity markers and pathways in C57BL/6J male mice / Mustafa Ahmed Al-Shagga
No full textIn East African and South Western Arabian populations, Catha edulis (khat) is
believed to suppress appetite and reduce body weight. First, this study conducted a
systematic review of the literature on the effects of khat and its active alkaloid cathinone
on body weight and appetite regulation. Second, this study investigated the effect of khat
and cathinone on selected metabolic and histopathologic parameters and their influence
on the expression of obesity-related genes in high-fat diet-induced obese mice. Forty-two
male C57BL/6J mice were divided into seven groups (n= 6); normal diet control treated
with vehicle (NDC), normal diet treated with 200 mg/kg khat extract (NDK200), high fat
diet control treated with vehicle (HFDC), high-fat diet treated with 200 mg/kg khat extract
(HFDK200), high-fat diet treated with 400 mg/kg khat extract (HFDK400), high-fat diet
treated with 3.2 mg/kg cathinone (HFDCAT) and high-fat diet treated with 15 mg/kg
orlistat (HFDO). The assigned diet was followed for 16 weeks, with treatment starting
from week 9 onwards. Treatments were carried out once daily by gastric gavage for 8
weeks.
The systematic review synthesised 15 studies and found that khat consumption is
associated with weight loss, appetite suppression, and relatively low triglyceride levels.
Nevertheless, studies on the effect of khat on leptin and insulin levels have yielded mixed
results, with no mechanistic studies available on the anti-obesity effect of this plant. In
our animal experiment. HFD groups gained significant body weight at week 8 than ND
groups (p<0.05). After 8 weeks of khat administration, the weight gains of HFDK400
(3.1 ± 0.6 g), HFDCAT (-0.4 ± 2.2 g), and HFDO (3.5 ± 3.8 g) groups gained less weight
than the HFDC (9.6 ± 4.3 g) group. The NDK200-treated mice ate less than the NDC
group, but the differences in weight gain were not statistically significant. HFDK200,
HFDK400, and HFDCAT had less fatty liver and lee fat body mass (p<0.05) and serum
triglycerides (p<0.05) than the HFDC group. A dose-dependent decrease in serum leptin
was observed in response to khat administration, and it was statistically significant in
HFDK400 treated mice (p<0.01), whereas the HFDCAT group was associated with low
insulin (p<0.01), low leptin (p<0.001) and low peptide YY (PYY) (p<0.05) levels than
the HFDC group. The adiponectin levels in HFDO (3.13 ± 0.3 ng/ml), HFDK200 (3.14 ±
0.6 ng/ml) and HFDK400 (3.16 ± 0.2 ng/ml) treated groups were significantly (p<0.05)
higher than the HFDC (1.20 ± 0.1 ng/ml) group. On the contrary, HFDCAT serum
iv
interleukin-6 (IL-6) (62.7 ± 10.1 pg/ml), was significantly (p<0.05) lower than HFDC
(110.1 ± 16.3 pg/ml), whereas serum resistin in HFDK200 (6.0 ±2.0 ng/ml), HFDK400
(3.8 ± 1.7 ng/ml) and HFDCAT (3.3 ± 1.5 ng/ml) groups showed significantly lower
levels (p<0.05) compared to HFDC (12.6 ± 1.4 ng/ml). Bone structural
histomorphometric parameters showed significantly higher bone volume density
(BV/TV) and less trabecular separation in HFDK200 and HFDCAT than the HFDC group
(p<0.05). However, HFDCAT had high osteoblast and osteoclast surfaces compared to
both khat extract treated groups.
The gene expression findings of adipose tissue showed upregulation of the lipolysis
pathway gene: adipose triglyceride lipase (PNPLA-2), which reported 3.3, 13.3, 19.3, and
17.7-fold changes for HFDO, HFDK200, HFDK400 (p<0.05), and HFDCAT,
respectively, compared to the HFDC vehicle-treated mice. Hormone-sensitive lipase
(LIPE) gene expression showed 4.4, 11.2, 19.9, and 11.1-fold changes upregulation for
HFDO, HFDK200, HFDK400 (p<0.05), and HFDCAT, respectively compared to the
HFDC group. HFDK400-treated mice were also associated with significant
overexpression of insulin receptor (INSR) (3.9-fold change), mechanistic target of
rapamycin (mTOR) (6.6-fold change), and Glut4 (3.9-fold change), whereas insulin
substrate-1 was upregulated in HFDCAT and HFDK200 (p<0.05) compared to the HFDC
group. Adiponectin (ADIPQ) showed 51- and 67-fold changes (p<0.05) for both
HFDK200 and HFDK400, respectively. Hypothalamic gene expressions revealed a
significant (p<0.05) upregulation of agouti-related peptide (AGRP) and cocaine�amphetamine regulated peptide (CARTP) genes in HFDK400 (2.5 and 1.9, respectively)
and HFDCAT group (4.5 and 4.3, respectively). HFDK200-treated mice showed a
significant (p<0.05) overexpression of hypothalamic IL-6 (3-fold change), while the
orlistat-treated group did not show any significant hypothalamic gene changes than the
HFDC group. In conclusion, the animal study demonstrated a significant effect of khat
400 mg/kg and cathinone on reducing body weight gain in diet-induced obese mice, and
this reduction is superior to orlistat. This study supports systematic review findings and
provides novel possible peripheral and central anti-obesity mechanisms of khat and
cathinone.
Keywords: Khat; Catha edulis; Cathinone; Obese mice; Mechanism of actio
Optimal placement of distributed generation in distribution networks for power loss minimization and voltage profile enhancement / Maszairisam bt Ameruddin
No full textDistributed generations (DGs) have emerged as an alternative to meet the growing demand of electrical energy and thus contribute to sustainable development of the nation. However, DG integration into the power system, particularly renewable energy resources such as Solar Photovoltaics (PV) and Wind Turbine (WT) introduce uncertainty in its operation due to the nature of the sources themselves. Therefore, proper planning and consideration have to be done prior to actual integration to ensure continuous supply and smooth operation of the system with minimal costs in-terms of power loss. In this regard, this research project proposes an approach for optimal placement of distributed generations in terms of renewable energy resources while satisfying the operation and technical constraints of the system such as power balance, voltage profile and lines thermal limits. The proposed approach is tested on a 33-bus radial distribution network employing the Forward and Backward Sweep Method (FBS) and Particle Swarm Optimization (PSO). Multiple scenarios are considered to show the impact of optimal location of PV and WT towards overall system performance. Finally, a complete model that integrates the performance and effectiveness of the proposed method in terms of power losses which is reduced from 10% to 40% from the base case (without DGs) and voltage profiles enhanced resulted from integration of PV and WT in the optimal locations have been demonstrated and presented
The relationship between musculoskeletal disorders and mental workload among female computer workers at services sector in Shah Alam / Muhammad Mohd Said
No full textThis study conducted to determine the relationship between musculoskeletal disorder and
mental workload among female computer workers. This study conducted on sixty (60) female
computer workers at services sector in Shah Alam. An assessment method to determine the
ergonomic risk level for the workstation is using the ROSA tool. The questionnaire
distributed is concerning the demographic data of respondents. The assessment of level
musculoskeletal disorders was assessed using the Cornell Musculoskeletal Discomfort
questionnaire. The mental workload level was evaluated using Carmen-Q and NASA-TLX.
The level of mental health is assessed using DASS-21. The data were analyzed using SPSS
version 20.0.
The level of ergonomic risk for workstation obtained is 5.54. 50% staff experience a severe
level of musculoskeletal disorders with majority of the workers experience discomfort at the
lower back (13.5%), neck (12.4%), and right shoulder (9.7%). For the hand region, the data
showed respondents are experienced discomfort at area A (11.96%), area B right (9.96%),
and at area E right (9.96%). NASA-TLX index showed that the subject assessed that Effort
Demand is the highest segment with 64.08%, Temporal Demand (63.67%). DASS-21
showed that most subjects have mental stress issues, with a percentage of 81.7%. For the
segment of DASS21 that symptomize, anxiety held at the highest rate followed by depression
in the 2nd place, with 15% of the respondents felt mild.
Pearson Correlation statistically showed a significant correlation between the total score of:
Weighted Workloads and total score for the MSDS body region, a few part of MSDS body
region with a few segment under mental workload score, total score of Weighted Workload
with MSDS right-hand, and MSDS hand left
Three-dimensional (3D) reconstruction of computer tomography cardiac images using visualization toolkit (VTK) / Mohammad Zahid Zamaludin
No full textCardiac study proves to be important to diagnose and treat cardiovascular disease that accounts for 20% of death in the world. Three-dimensional (3D) images of the heart are important to understand its real structure, functions and physical abnormalities occurring in the tissue. The objective of this paper is to reconstruct 3D images from 2D CT Scan slices of the cardiac region of interest using Visualisation Toolkit (VTK). The Visualization Toolkit (VTK) is non-propriety software with state-of-the-art tools for 3D rendering that is easily customizable programming. 3D images are reconstructed using surface rendering technique and volume rendering technique. Volume rendering shows best rendering quality compared to surface rendering when reconstructing cardiac 3D images. Artery structure are easily identifiable using volume rendering in VTK whereas surface rendering image yielded false positive or false negative images. VTK capabilities are also compared RadiAnt DICOM Viewer. The 3D image rendered match the quality of RadiAnt 3D image