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Performance analysis of swipt enabled non-orthogonal multiple access assisted multiple relay cooperative networks / Mahrukh Liaqat
No full textNon-orthogonal multiple access (NOMA) scheme is emerging as a favorable multiple access scheme for future 5G networks. Compared to orthogonal multiple access (OMA) techniques, NOMA provides spectral efficiency, user fairness, better connectivity, enhanced data rate and reduced latency. On the other hand, in wireless networks, cooperation is a well-recognized technique for performance enhancement. Cooperative networks offer multiple desirable advantages, including high performance, reliability and greater coverage area. NOMA has features that can provide opportunities of improved performance and better spectral utilization for downlink cooperative networks.
Modern communication systems operate under energy constraints. Simultaneous wireless information and power transmission (SWIPT) is a way of energy harvesting (EH), which allows to exploit the same RF signal for both EH and information processing. Integration of Cooperation, NOMA and SWIPT can provide energy efficient, reliable and spectral efficient networks. Therefore, this study aims to design energy harvesting enabled cooperative NOMA (C-NOMA) networks. In the first part, multiple relay downlink cooperative NOMA network with SWIPT is investigated where both useful signal and interfering signals are used to harvest energy. The closed form analytical expressions of outage probability are derived. Subsequently, impact of various parameter, including, number of available relay nodes, interfering signals, energy harvesting parameter, and energy conversion efficiency is shown on performance of proposed networks. The finding showed that system performance improves with the number of intermediate relaying nodes, transmit power, power of external interfering source and energy harvesting efficiency. It was identified that optimal location of relaying nodes is nearest to source.
For device to device communication, it is important to consider spatial distribution of dynamically distributed users. Second part of the research focused to investigate the SWIPT enabled C-NOMA networks in the presence of interference with cooperation among spatially distributed NOMA users. The mathematical model to evaluate the outage probability and system throughput are provided and analyzed. The results demonstrated the positive impact of transmit SNR, number of available cooperating device, interference power and conversion efficiency, while performance was deteriorated with increase in radius of cooperative area and higher data rates.
Due to energy harvesting, multiple channel gains get involved and best relay cannot be selected straightforwardly. In the third part of the work, a new relay selection scheme for C-NOMA networks with SWIPT is proposed. The selection scheme was designed by carefully considering all involved channels and circuit power consumption at relay node. Additionally, the selection scheme was extended of dynamic power allocation factors of NOMA users. For the proposed two-stage relay selection analytical expression of outage probability for delay-limited transmission are provided. A comparative analysis of partial relay selection and two-stage relay selection was conducted to find which schemes performs better under certain conditions. It was revealed that proposed scheme provides significant performance improvement, particularly at higher transmit SNR and number of relays. For all relay selection schemes, the optimal relay location was found closer to source node
The effects of fillers on the surface morphology, mechanical properties and protein content in natural rubber latices / Ruhida Ab Rahim
No full textThe purpose of adding fillers into rubber products is not only as a cheapening aid but also to improve the properties of the end products. In this study, the untreated and stearic acid (SA)-treated calcium carbonate (CaCO3) were used as a filler into the mixed clones natural rubber latex concentrate (MCLC). The MCLC was prepared by processing the monoclones field latex, namely RRIM2023, RRIM2024 and RRIM2025, at a similar weight ratio. The untreated filler loadings mixed into MCLC varied from 10 to 40 parts per hundred rubber (pphr). The CaCO3 treated with SA at various concentrations of 0.5%, 1.0%, 3.0%, 4.0%, 5.0% and 7.0% by % (w/v) in chloroform was mixed into MCLC at 30 pphr filler loading. The MCLC films at different untreated filler loadings were evaluated for their properties chemically and physically. Results obtained were evaluated and compared to observe the occurrence of chemical interferences, if any, on the determination of extractable proteins (EP) content. The addition of the SA-treated CaCO3 at various concentrations of SA was to improve the filler-rubber interaction and to reduce the amount of EP content extracted from the MCLC films. The SA-treated CaCO3 was characterised by using Fourier-Transform Infra-Red (FTIR) and Thermogravimetric analysis (TGA) to identify the presence of stearic acid on the surfaces of CaCO3 particles. The percentage of nitrogen (N) and EP contents were measured using the Automatic Analyser and UV Microplate Reader, respectively. The EP content of MCLC films was also measured before and after exposure to ozone at 10 parts per hundred million (pphm) concentration, and the surface morphology of MCLC films was monitored before and after exposure to ozone. Their tensile and tear strengths were determined as well as their total, combined and free sulphur contents. The results of latex properties such as dry rubber content (DRC), total solids content (TSC), alkalinity (NH3) and volatile fatty acid number (VFA No.) showed that the MCLC prepared from MCFL is clean, stable and free from foreign matters and non-polymer impurities. The cross-link concentration of samples was also being measured by the Flory-Rehner equation to identify that the presence of CaCO3 in samples has the ability to influence the cross-link concentration. It was found that the addition of the filler below 20 pphr affected the cross-link concentration. The percentage of combined sulphur of unaged samples decreased from 22% until 37% and aged samples from 24% until 43%. The tensile strength of the unaged sample decreased from 10% to 20% and aged samples from 10% to 29%. Therefore, decreasing the percentage of combined sulphur led to a reduction of the tensile strength of MCLC films. The total protein contents on the MCLC films at different filler loadings showed that the values were higher in the unaged samples as compared to aged samples (70 ºC for 7 days). From TGA analysis, the presence of stearic acid can only be detected at filler treated at 3.0% concentration of stearic acid. FTIR analysis showed that the absorption peak at 875 cm-1 indicated that the stearic acid might be attached to the CaCO3. The nitrogen (N) content of the unaged and aged samples at 3.0% stearic acid treated CaCO3 was similar. However, all corrected and non-corrected EP contents for unaged samples were lower compared to the Control sample (untreated CaCO3). The highest value of corrected EP content was 417.4 μg/g obtained from latex mixed with 3.0% treated filler. The results of the EP contents were reported as non-corrected and corrected values. In the corrected method, the copper reagent was replaced by water in an alkaline tartrate solution in the colour development stage during the protein assay. The results of corrected and non-corrected EP contents for the aged, treated samples were found to be inconsistent and was attributed to the heating and ageing processes. Contrary to expectation, the non-corrected EP content was lower compared to the corrected EP content. The tensile strength of unaged SA-treated CaCO3 results shows an increase from Control 1 to 0.5% SA-treated before being reduced from 1.0% to 7.0%. Nevertheless, the MCLC films with the SA-treated CaCO3 showed no significant difference in tensile strength after ageing but higher than the Control 1 (untreated CaCO3). The tear strength of unaged samples was higher as compared to aged samples
Genetic variation analysis of a primary immunodeficiency patient via whole-exome sequencing approach / Bader Abdul Kader El Farran
No full textPrimary Immunodeficiency (PID) refers to a collection of diseases whereby the production of antibodies is negatively affected, or the cellular defenses of the immune system do not operate appropriately. A Malaysian patient (P1) was initially suspected with a PID type known as Hyper IgM syndrome. However, the immunological workup was not compatible with Hyper IgM syndrome. Hence, a Whole-exome sequencing (WES) analysis was conducted to look for mutations in PID-related genes. P1’s raw data were mapped to four different versions of the human reference genome to compare the results and determine which one is the best for this analysis. Once the variants were called from P1’s data they were annotated to search for mutations. As a result, a novel mutation was detected in the Nuclear factor-kappa-B-inhibitor alpha (NFKBIA) gene, which is responsible for regulating the Nuclear factor-kappa-B (NFKB) gene. It is a single nucleotide polymorphism (SNP) (NFKBIA:NM_020529:exon1:c.A94T:p.S32C) at codon 94 (c.A94T) of P1’s NFKBIA gene which resulted in the mutation of the serine residue (Ser32) to a cysteine residue (Cys32). This SNP lies in the destruction motif of the NFKBIA protein, which may have led to the impairment of NFKB activation in P1, which could explain the symptoms of the patient. Since this is a novel mutation, it warrants future investigation to find out what such mutation exactly does to the NFKBIA protein structure and how it affects its interaction with NFKB
Pembangunan kerangka domain pengajaran bahasa Arab bagi pengajar di pusat tahfiz / Ali Trimahno Ahmad Turmudi
No full textKajian ini bertujuan untuk membangunkan kerangka Domain Pengajaran Bahasa Arab Bagi Pengajar di Pusat Tahfiz. Pembinaan kerangka ini adalah bertujuan untuk menjadi suatu garis panduan terhadap kompetensi dan domain pengajaran yang perlu dikuasai oleh para guru dan pengajar Bahasa Arab di Pusat Tahfiz. Kajian ini menggunakan pendekatan Kaedah Fuzzy Delphi (FDM) dalam membangunkan matriks domain pengajaran dan elemen yang terkandung di dalamnya dengan berdasarkan pandangan dan kesepakatan kumpulan panel pakar yang terdiri daripada 25 orang iaitu 20 orang dalam kalangan guru tahfiz itu sendiri dan 5 orang pakar adalah dalam kalangan guru Bahasa Arab. Kesemua pakar ini juga mestilah mempunyai pengalaman mengajar di Pusat Tahfiz sekurang-kurangnya lima tahun. Hal ini adalah berasaskan pandangan Berliney yang menghujahkan bahawa seorang guru dianggap pakar apabila mempunyai pengalaman mengajar lebih daripada lima tahun. Dapatan kajian memperlihatkan bahawa terdapat lima domain pengajaran yang perlu dikuasai oleh guru dan pengajar yang mengajar bahasa Arab di Pusat tahfiz iaitu 1) Persediaan Guru; 2) Pemahaman Konsep; 3) Penyediaan Tugasan & latihan; 4) Pengukuhan PdP dan; 5) Penilaian. Bagi domain Persediaan Guru, ia adalah meliputi elemen Guru tahfiz hendaklah menjalankan penyusunan awal proses PdP yang berasaskan penggunaan Bahasa Arab meliputi skema sedia ada kepada pelajar dan hendaklah menjalankan proses pengenalan menggunakan Bahasa Arab yang mampu menarik perhatian pelajar dalam proses menghafaz Al-Quran. Manakala domain Pemahaman Konsep adalah meliputi elemen Guru tahfiz hendaklah mampu memberikan contoh-contoh input yang berguna sebagai motivasi kepada pelajar dalam menjalankan proses hafazan dan hendaklah mampu mengemukakan maklumat yang berguna dalam Al-Quran sebagai asas kepada pemantapan hafazan pelajar dan hendaklah mampu melakukan pengembangan yang merangkumi penerangan jelas tentang maklumat yang baik dalam Al-Quran kepada pelajar. Domain Penyediaan Tugasan dan latihan pula adalah melibatkan elemen Guru tahfiz menerangkan proses inkuiri yang perlu diaplikasikan oleh pelajar dalam menyelesaikan masalah hafazan yang dihadapi dan hendaklah mampu menentukan dan mengemukakan masalah yang sering terjadi dalam proses menghafaz Al-Quran. Guru tahfiz hendaklah mampu menjalankan latihan terbimbing secara aktif bagi meningkatkan ingatan kepada pelajar. Bagi elemen Pengukuhan PdP adalah terdiri daripada elemen Guru tahfiz hendaklah berupaya membantu pelajar untuk menguji hipotesis yang dijalankan dalam proses menghafaz Al-Quran menggunakan Bahasa Arab dan berupaya membimbing pelajar dalam membuat hipotesis dengan mengumpulkan data permasalahan yang mereka hadapi dalam proses menghafaz Al-Quran menggunakan penggunaan Bahasa Arab. Domain terakhir iaitu penilaian adalah mengandungi elemen Guru tahfiz hendaklah berupaya merumuskan proses pengajaran hafazan yang diajar kepada para pelajar setelah selesai pengkuliahan dijalankan dan mampu menjalankan penilaian latihan kendiri dengan menggunakan bahasa arab yang bertujuan untuk membantu pelajar menentukan tahap penguasaan yang dicapai pelajar dan mampu melaksanakan ujian yang menggunakan bahasa arab untuk melihat pencapaian hafazan pelajar dan juga mahir dengan proses penilaian yang digunakan untuk mentaksir kemajuan pelajar sama ada secara formatif dan sumatif. Kesemua domain dan elemen ini dilihat mampu digunakan sebagai suatu panduan kepada para guru dan pengajar Bahasa Arab di Pusat Tahfiz
Explosion characteristics of aluminium and silver particles in various sizes and concentrations for a confined and vented system / Khairiah Mohd Mokhtar
No full textThe rising metals applications in electronics, aerospace, and solar cell industries could potentially lead to a destructive dust explosion. To assess the associated hazard and appropriate preventive and mitigation measures against the accidental metal dust explosion, it is crucial to identify the physicochemical properties particularly on kinetic reaction mechanism and explosion characteristics of metal powder. Thus, in this work, the explosion characteristics of two metals powder viz; aluminium (Al) and silver (Ag) were explored in a 0.0012 m3 cylindrical vessel, by varying the particle sizes and the powder concentrations. It was found that the Minimum Explosion Concentration (MEC) for both aluminium and silver was 300 g/m3. The experimental results showed that the maximum explosion pressure (Pmax) and maximum rate of pressure rise (dP/dtmax) increase with the increasing powder concentration from 300 g/m3 to 500 g/m3, however, the decreasing trend was observed when the concentration values exceeding ~ 700 g/m3. The shortened inter-particle distance and oxygen deficiency at higher powder concentrations give a significant reduction in the heat transfer rate, and hence, it lowers the explosion severity. Further, the decrease values of both Pmax and dP/dtmax were also shown when the agglomeration effect occurred at smaller particle size. The lower particle weight gaining of Al 40 nm in the thermogravimetric (TG) curve, than Al 70 nm, reflects on the slower oxidation reaction of the particles due to the agglomeration effect. In contrast to aluminium powder, sluggish oxidation was shown in the TG curve of silver powder corresponding to the smaller specific surface area of silver powder, and this condition justifies the lower explosion severity of silver powder than that of aluminium powder. Further experimental works were conducted on the aluminium and silver (Al-Ag) mixtures which can be encountered in the passivated emitter and rear contact (PERC) solar cell industry. The finding demonstrates that the explosion severity of Al-Ag mixtures is lower than the pure aluminium powder explosion, with the most significant effect was observed when the silver powder is in excess. The Pmax and dP/dtmax of 40:60 mixing weight ratio of Al-Ag mixtures is approximately one-fifth of the values obtained in the pure aluminium powder. It can be depicted that the silver powder disrupts the aluminium oxidation reaction, hindering the heat transfer among the metal particles which leads to the reduction of the mass burning rate, and hence, lowering the explosion severity of the aluminium. Based on the kinetic mechanisms, it can be suggested that the reduction of aluminium explosion severity in 50:50 and 40:60 mixing weight ratio of Al-Ag mixtures corresponds to the amount of unreacted aluminium. In addition to the role of silver powder, the magnitude of aluminium explosion severity was also decreased in the vented explosion. However, the venting effectiveness reduces as the static burst pressure (Pstat) of the venting membrane increases. The explosion pressure of Al 70 nm was reduced by about 60% when Pstat of 0.5 bar was applied, gave approximately 30% lower value than the pressure obtained at the 0.1 bar Pstat
Mediating effect of self-compassion on the relationship between academic procrastination & academic burnout among undergraduates in a Malaysian public university in Klang Valley / Lim Wee Lee
No full textThe direct relationship between self-handicapping behavior and negative mental health outcomes had been demonstrated in past study. Researchers had suggested a further investigation into the mechanism by which the direct effect is established. On the other hand, the role of self-compassion act as a protective factor (i.e. as a mediator) against negative mental health outcomes had also been demonstrated among tertiary students in other countries. However, it is not known whether these relationships hold true in the Malaysia educational context. The purpose of this quantitative study was to examine the relationship among academic procrastination (an example of self-handicapping behavior), academic burnout (a negative mental health outcome) and self-compassion. Also, to investigate the mediating role of self-compassion in the relationship between academic procrastination and academic burnout among undergraduates in a Malaysian public university, particularly in Klang Valley area. Hence, the study was driven using a cross-sectional research approach. The mediation analysis was made based on the total 400 students’ responses that revealed from the questionnaire instruments, which includes SCS, APS, and UBI. The data analysis performs using SPSS and AMOS program in examining the correlation and mediation effect of self-compassion on the variables. The findings revealed all variables are statistically significant correlated to each other, except there is no significant relationship between academic procrastination and positive component of self-compassion. Furthermore, the results showed that only negative component of self-compassion partially mediates in the relationship between academic procrastination and academic burnout. The implication and recommendation for future studies are discussed as well
Moderating role of gender diversity over The NEXUS between board characteristics and earnings management in Malaysia / Tonoy Roy
Get PDFIn a large number of studies, it has been found that accounting manipulation is more
prone to exist among the financially distressed companies. The manipulation moves were
taken by the top management to portray a rosy picture of the fir
Molecular dynamics simulations of DARPins as potential inhibitors against cancer associated protein kinases / Vertika Gautam
Get PDFOut of all post-translational modifications, Protein phosphorylation is the most common in signal transduction, that occurs through protein kinases. Extracellular Regulated Kinase 2 (ERK2) is a type of protein kinase that undergoes phosphorylation to control various pathological and physiological phenomena. The deregulation of ERK2 often implicated in several types of cancers, for example, pancreatic, lung and breast. The current therapeutic treatment for this type of cancers involves blocking cellular proliferation signals by targeting kinases. However, the drugs developed resistance after prolonged use. Thus, the discovery of alternative ERK2 inhibitors is in need. In the present work, the potential of a class of repeat proteins - Designed Ankyrin Repeat Proteins (DARPins) is studied as ERK2 inhibitors, using computational chemistry approaches. The structural basis of ERK2-DARPin interactions based on molecular dynamic (MD) simulations and role of water molecules in the binding region of the protein-protein complexes was characterized using 3D Reference Interaction Site Model (3D-RISM). The information was then used in designing more DARPin mutants using single point mutations which were subsequently subjected to MD simulations and binding free energy calculations. Two mutants; A443D and S380L, were predicted to perform better than the original sequence (wild-type DARPin) based on the associated energy, the dynamics of global motions, and key residues involved in protein-protein interaction. This study showcases the use of computational chemistry tools in understanding proteinprotein interactions and designing specific inhibitors against cancer-associated protein kinases
Molecular and structural monitoring of epithelial mesenchymal in breast tissue / Siti Norbaini Sabtu
No full textThe epithelial mesenchymal transition (EMT) is a crucial process in cancer progression and metastasis. Study of metabolic changes during the EMT process is important in seeking to understand the biochemical changes associated with cancer progression, not least in scoping for therapeutic strategies aimed at targeting EMT. Raman spectroscopy and synchrotron small angle x-ray scattering (SAXS) were used herein to study the metabolic changes associated with EMT in human breast cancer tissue. For Raman analysis, tissue from 23 patients were collected, comprising non-lesional, EMT and non-EMT breast cancer samples. Analysis was made in the fingerprint Raman spectra region (600 -1800 cm-1). Multivariate analysis involving Independent Component Analysis (ICA), Principal Component Analysis (PCA) and Non-Negative Least Square (NNLS) were used to analyse the Raman spectra data. The results show significant differences between EMT and non-EMT cancers in lipid, protein, and nucleic acids. Using SAXS techniques, structural components of the tissues were examined at momentum transfer values between q = 0.2 nm-1 and 1.5 nm-1. From the SAXS patterns, axial d-spacing and diffuse scattering intensity were observed to provide the greatest discrimination between the various tissue types. The overall intensity of scattering from cancerous regions is a degree of magnitude greater in cancer-invaded regions.Present results indicate that as aids in tissue diagnosis SAXS are capable of distinguishing areas of invasion by disease as well as delivering further information at the supramolecular level
Accreditation performance in area 2: Curriculum design and delivery among undergraduate medical education programmes in Malaysia / Ahmad Soufi Ahmad Fuad
No full textAccreditation exercise of undergraduate medical education in Malaysia involves
Malaysian Qualification Agency (MQA) and Malaysian Medical Council (MMC);
which was established with the aim of quality assurance. The exercise involves
evaluation of medical education programme on nine (9) areas. The present study
focuses on Area 2 - Standards of Undergraduate Medical Education, which is
curriculum design and delivery. There is paucity of research on conducting
accreditation exercise on medical undergraduate medical education in Malaysia. In the
present study, analysis was used to identify strengths and improvements of medical
curriculum as being reported in accreditation visit reports. Contents in forty-two (n=42)
accreditation visit reports of both public and private institutions were analyzed. Items
of strength and improvement are identified based on the Area 2 evaluation criteria,
which is (i) curriculum design and teaching learning methods, (ii) scientific method,
(iii) curriculum content, (iv) ethics and humanities, (v) management of programme, and
(vi) linkages with external stakeholders. The findings are then mapped to the six (6)
strategies of Harden’s “SPICES” model. It was found that the component of curriculum
evaluation in Malaysia is aligned with internationally recognized benchmark for
curriculum design and delivery, that is the “SPICES” model. A quantitative analysis
was conducted to determine the association between types of institution and
accreditation performance. From the analysis, twenty-five (25) programmes (59.5%)
received duration of accreditation status less than 5 years period and seventeen (17)
programmes (40.5%) received the maximum duration of accreditation status (5-years
period). Out of all programmes that received the maximum accreditation period, nine
(9) were public institutions (52.9%) and eight (8) are private institutions (47.1%). For
programmes that received duration of accreditation period less than 5 years, twenty-
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one (22) were private institutions (88.0%) and only three (3) were public institutions
(12.0%). The association was statistically significant where public institutions have a
longer duration of accreditation period (p<.01). In terms of Area 2 performance, all
twelve (12) public institutions (100%) received Area 2 average score of 76% or more.
On the other hand, only nineteen (19) private institutions (65.5%) received Area 2
average score equal or more than 76%. The remaining ten (10) private institutions
(34.5%) received Area 2 score less than 76%. There was also a significant association
between types of institution with performance in Area 2. Public institutions have higher
scores on Area 2 evaluation (p<.05). The present study initiated a pioneering attempt
in analyzing MQA/MMC accreditation data for the purpose of academic analysis.
Future studies could analyze other areas of evaluation and thus providing a robust
analysis.
Keywords: accreditation, curriculum evaluation, medical educatio