University of Technology Malaysia
Universiti Teknologi Malaysia Institutional RepositoryNot a member yet
70456 research outputs found
Sort by
Register-transfer-level Hardware Trojan classification boosted with gate-level features
No full textHardware Trojan (HT) is an alarming hardware security threat which has gained increased awareness over the last decade. Due to the emerging threat of HT, ensuring trustworthiness in an integrated circuit (IC) has become an important aspect to be considered during manufacturing. Hence, the design process of ICs must be reviewed to avoid HT insertion by malicious third-party vendor. The purpose of this research is to develop a HT detection method in register-transfer-level (RTL) description with an improved HT coverage compared to the other previously proposed methods. The proposed method discovered HT branching statement in the RTL description by utilising a supervised machine learning classifier based on ten (10) proposed two-abstraction-level features. The proposed two-abstraction-level features relevant to HT characteristics included branching probability features extracted at RTL and net testability features extracted at gate-level (GL). The effectiveness of the proposed features in detecting HTs with 19 Trust-Hub benchmark circuits were demonstrated. The Minimum Redundancy Maximum Relevance (mRMR) feature selection algorithm was utilised to prove that the combination of the proposed features can achieve maximum accuracy (ACC) of 99.97% in detecting HTs during classifier training. To avoid overfitting issue, the trained classifiers were further evaluated with a classifier testing experiment on unseen circuit. The unseen circuit was completely independent of the training data, and it consisted of 24 HT circuits derived from a genuine Keccak encryption circuit. By using a set of proposed HT stealthiness assessment measures, the HT coverage of the classifiers was evaluated. The decision tree (DT) classifier with the two-abstraction-level features achieved the highest 87.5% HT coverage with 81.25% true positive rate (TPR), 88.44% true negative rate (TNR), and 88.24% ACC respectively. The results proved that the two-abstraction-level features outperformed single-abstraction-level features with higher HT detection coverage
Biotransformation of caffeine, gliclazide and prazosin in an up-flow anaerobic sludge blanket reactor
No full textUp-flow anaerobic sludge blanket (UASB) reactors are largely utilised as an anaerobic reactor configuration to efficiently treat various wastewater streams. However, previous UASB operations for the removal of pharmaceutical compounds at low hydraulic retention time (HRT) resulted in poor chemical oxygen demand (COD) and removal efficiencies for the investigated compounds. Anaerobic process performance has also been found to be vulnerable towards pharmaceutical compounds at high concentration levels but there is no evidence to indicate if the same effects will be induced when other compounds are present at trace concentration levels. This research aims to establish the relationship between pharmaceutical compound removal, influencing parameters, and anaerobic process performance. In this research, caffeine, gliclazide, and prazosin were selected based on their environmental occurrences, persistency, and toxicity. The compounds were investigated as a mixture to simulate their concurrent occurrences in the same actual wastewater stream. The first part of the research investigated the biodegradability of the three compounds in an anaerobic batch experiment. Synthetic wastewater and inoculum mixture were spiked with 1 mg/L of mixed pharmaceutical compounds and incubated at mesophilic condition (37°C) for 90 days. All compounds achieved removal through biotransformation between 44 - 99% by the end of the incubation period. The second part of the research was commenced by running five experimental phases in an acclimatised laboratory-scale UASB reactor. Phases I - V were carried out to assess the effect of pharmaceutical concentrations (0.1 – 1 mg/L), HRT (36 – 48 hours) and different reducing conditions (predominant methanogenic and simultaneously reducing conditions) to the removal of pharmaceutical compounds and UASB process performance. Overall, biotransformation remained the predominant removal pathway in the laboratory-scale experiments despite the changes in pharmaceutical concentrations and HRT. Only gliclazide recorded an improvement of biotransformation up to 99% under simultaneous reducing conditions compared to that in predominant methanogenic conditions. The UASB reactor was also operating in a stable condition (COD removal efficiency of 93 ± 2%) but fluctuations were recorded in the production of individual volatile fatty acids (VFAs) and biogas. Microbial assessment through 16s rRNA sequencing justified the changes in VFAs production based on the effect of the pharmaceutical compounds towards the growth of hydrolytic and fermentative bacteria. The compounds also shifted the composition of methanogenic archaea by favouring hydrogenotrophic methanogens (59 - 72%) over acetoclastic methanogens (15 - 31%) under predominant methanogenic conditions
Ternary magnetic biochar composite from Citrullus Lanatus rind for supercapacitor’s electrode
No full textMetal oxides and conducting polymers are renowned as some of the promising materials for electrochemical energy storage (EES) devices, which include batteries, supercapacitors, and hybrid EES devices. This is due to their unique redox properties, significant theoretical capacitance, and environmentally benign nature. However, unsupported metal oxides and conducting polymer nanostructures suffer from particle aggregation, which decreases their electrochemical surface area. In recent years, the preparation of EES from renewable biomass has been developed taking into consideration the economic and environmental feasibility. Biochar is one of the major products of the thermochemical conversion of biomass. Applications of biochar for agricultural and environmental areas have been studied and reviewed extensively but biochar for energy storage materials has not been widely explored and examined. Therefore, the aim of this study is to convert the watermelon rind (WR) into magnetic biochar through a single-route self-purging pyrolysis method. Binary metal oxides (BMOs), such as nickel ferrite (NiFe2O4) and cobalt ferrite (CoFe2O4), were impregnated in dried watermelon rind to incorporate metal ions into the magnetic biochar. Response surface methodology (RSM) was employed to determine the magnetic watermelon rind biochar (MWRB) synthesis conditions (pyrolysis temperature, pyrolysis time, and WR: BMO ratio). The optimised magnetic biochar was combined with polyaniline (PANI) to produce a ternary magnetic biochar composite with PANI (TC-MWRB/PANI) via in-situ polymerisation to further enhance its electrochemical performance. RSM was also implemented to determine the TC-MWRB/PANI synthesis conditions (PANI concentration, sonication time, and sonication amplitude). Characterisations were done through field emission scanning electron microscopy (FESEM), energy dispersive Xray spectroscopy (EDX), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Brunauer-Emmett-Teller (BET) surface area, and vibrating sample magnetometer (VSM). Electrochemical evaluations were performed through cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS). The XRD and FTIR results confirmed the successful formation of MWRB and TC-MWRB/PANI. The FESEM images revealed the porous structure of MWRB and fibrous-look PANI embedded on the surface of TC-MWRB/PANI, while the EDX results showed their associated elemental composition. The electrochemical investigations revealed excellent electrochemical performance of the MWRB and TC-MWRB/PANI for energy storage applications. Based on the electrode specific capacity, the regressed model and experimental results for the fabricated MWRBNiFe2O4 and MWRBCoFe2O4 were determined to be 191 C g-1 and 187 C g-1 and 200.05 C g-1 and 200.96 C g-1, at 5 mV s-1, respectively. In addition, the electrode specific capacity based on the regressed model and experimental results for the fabricated TC-MWRBCoFe2O4/PANI were determined to be 488.22 C g-1 and 491.29 C g-1. A two-electrode configuration with TC-MWRBCoFe2O4/PANI as a positrode and watermelon rind biochar (WRB) as a negatrode was fabricated to form a hybrid device (supercapattery) that operated in a stable potential window of 1.5 V. The energy density and power density of the device measured at a current density of 4 A g-1 were estimated to be 22.45 Wh kg-1 and 833.19 W kg-1, respectively. The fabricated supercapattery showed excellent cyclability with 97.46% specific capacity retention after 5,000 cycles
Preparation and characterization of inverse vulcanized copolymers using taramira oil
No full textInverse vulcanization reaction has been previously utilized in diverse range of studies however, those studies used petroleum derived, terpenes and edible vegetable oils as monomers for this reaction. The depleting abundance, high synthesis and purification cost and high food market demand make them less sustainable feedstocks. Herein, we reported the synthesis of the inverse vulcanized copolymers utilizing abundantly available non-edible oil as alternative monomer. The properties of the obtained copolymers were evaluated using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Powdered X-ray Diffractogram (p-XRD). Disappearance of the cis alkene characteristics (at 1660 and 3009 cm-1) peaks from spectra of all copolymers and appearance of new peak at 804 cm-1 confirms the formation of the copolymer and presence of some unreacted sulfur was revealed by p-XRD as some crystalline peaks appeared in the diffractogram. SEM images revealed the composite morphology of copolymers and confirmed the presence of unreacted sulfur particles. So, it can be concluded that taramira oil can be successfully used as an alternative monomer to edible oil with same results
The implementation of the MCMC official pool vehicle booking system (KERETA2U)
Get PDFThe current process of the MCMC Pool Vehicle Booking is still manual i.e. submission of application via hardcopy form, which led to time-consuming. Further, there is no notification system to the end-user on the status of pool vehicle application where typically the user has to follow up via phone call/WhatsApp to the administrator. From the administrator perspective, they have difficulty in terms of reporting and perform analysis to obtain valuable insights due to the manual process. The objectives of this research (for Action Research 1) is to understand the effectiveness of the current process of the Official MCMC Pool Vehicle Booking and to understand how the implementation of Kereta2U system can improve the current process as well as to identify Kereta2U’s user requirements. A mixed-method approach was used in this research, which included observation, interview and survey with a total of 36 respondents. Based on the data analysis and research findings, it was identified that the current process of MCMC official vehicle booking is not effective and improvement to the existing process has been introduced. The high level technical requirements have been presented based on the requirement from both user and process owner. Aside from that, the prototype of the Kereta2U system has been developed and impact assessment has been analysed in Action Research 2 (Cycle 2). Overall, the findings show that the implementation of Kereta2U will provide significant benefits to the end user, driver and administrator
Distance-aware bidirectional medium access control for mesh wireless network-on-chip architecture
No full textWireless Network-on-Chip (WiNoC) architectures have recently been proposed to address the scalability limitations of conventional multi-hop wired NoC architectures. The medium access control (MAC) protocol and routing strategy are critical in determining the performance and energy characteristics of a WiNoC. Most conventional WiNoC MAC use a daisy-chained ring topology, which limits the performance benefit of using a wireless channel since daisy-chaining results in a maximum waiting time when a radio hub misses the token before a packet arrives. Furthermore, even when radio hubs are connected to wired paths, all cores connected to the WiNoC radio hub prioritise transmission through the radio hub, resulting in an uncontrolled load on the wireless channel. Therefore, this thesis’s main objectives are as follows. The first objective is to propose a Bidirectional MAC (B!"#) strategy for WiNoC while the second objective is to propose a Distance-Aware (D") routing scheme in conjunction with B!"# (D"+B!"#) to control a single-hop wireless transmission exclusive to far away destination cores. The wired metal planar interconnect has a higher aggregate bandwidth and is dedicated to short-range communication, whereas single-hop wireless channels are dedicated to long-range transmission beyond a certain distance threshold. To determine the effectiveness of the proposed works, a comprehensive validation was performed using the cycle-accurate Noxim simulator. The proposed strategy was tested and validated in terms of latency, throughput, and energy consumption using synthetic traffic distributions (random, shuffle, transpose, and hotspot) and real-application PARSEC (Barnes) and SPLASH-2 (Fluidanimate) traces. Extensive simulation results show that B!"# can achieve up to 1.84 times faster throughput, while D"+B!"# can improve up to 11.49 times faster than the WiNoC baseline daisy-chained architecture. At the same time, the energy improvement over the baseline daisy-chained at the saturated packet injection load is up to 8% for B!"# and 15% for D"+B!"#. The proposed MAC and routing protocols increase wireless channel utilisation and balance wireless-wired load, resulting in significantly improved WiNoC performance over the baseline architecture
Least-squares finite element method for solving stokes equation with a point source magnetic field
No full textThe formulation and numerical computation of the two-dimensional Stokes flow under the effect of a point source magnetic field are presented in this study. Stokes flow is also known as low Reynolds number, creeping flow, or non-inertial. Leastsquares finite element method (LSFEM) is successfully employed for the discretization of the Stokes equation. LSFEM has several advantages in terms of theory and computing, and it can create a symmetric and positive-definite algebraic system of equations that can be solved quickly and robustly using iterative approaches. However, LSFEM is having an issue where the low order nodal expansions tend to lock. Thus, the present study proposed the discretization of the problem domain using higher-order elements. The source codes for the Stokes equation with and without the point source magnetic field effect have been developed and verified against the existing benchmark solutions. The verification achieved an excellent agreement. The solution of the Stokes flow in a lid-driven cavity and a straight rectangular channel subjected to the point source magnetic field are conducted. The results concerning velocity contour and streamlines pattern are analysed. Firstly, the streamlines pattern in the lid-driven cavity problem shows the development of a vortex at the bottom-left corner cavity. The new vortex appeared as the secondary flow in cavity. As the magnetic number grows, the primary flow separates from the secondary flow. Secondly, when the straight rectangular channel problem was solved, a single vortex which is close to the point of the magnetic source. As the magnetic number increased, a new vortex appeared at the channel's upper wall. This shows that the point source magnetic field has a substantial impact on Stokes flow, as shown by the numerical simulation findings. Based on the current results, it can be concluded that the LSFEM can be used to solve Stokes flow problems with the effect of the point source magnetic field
Effect of natural ferrite oxide nanoparticles on structural and magneto optic properties of erbium doped tellurite glass
Get PDFTwo series of erbium doped magnesium tellurite glasses embedded with Fe3O4 nanoparticles (NPs) with composition (89-x) TeO2 - 10MgO - 1Er2O3 - (x) Fe3O4, where (x = 0, 0.2, 0.4, 0.6 and 0.8 mol%) and (89.6-y) TeO2-10MgO-(y) Er2O3-0.4Fe3O4, where (y = 0.2, 0.4, 0.6, 0.8 and 1.0 mol%) were prepared using melt quenching technique. Thorough characterizations of these glasses were made using X-ray diffraction (XRD), differential thermal analyzer (DTA), ultraviolet-visible-near-infrared (UV-Vis-NIR), Fourier transform infrared (FTIR), Raman spectroscopy, photoluminescence (PL) spectroscopy, energy dispersive X-ray (EDX), high resolution transmission electron microscopy (HRTEM), vibrating sample magnetometer (VSM) and electron spin resonance (ESR) spectroscopy. The presence of a broad hump in the X-ray diffraction (XRD) pattern confirms the amorphous nature of glass. HRTEM images verified the existence of Fe NPs with average diameter of 4.8 nm (TMEF3 sample) and 4.5 nm (TMFE3 sample) corresponding to d311 spacing. The glass density and molar volume were found to be in the range of 4.03-5.27 gcm-3 and 37.20-28.54 cm3 mol-1, respectively. It was also found that as the amount of Fe3O4 NPs was increased, the glass stability increased. DTA analysis demonstrated an increase in the glass transition temperature from 321 oC to 363 oC with the increase of Fe3O4 NPs. The UV-Vis-NIR absorption spectra revealed seven absorption bands centered at 452 nm, 522 nm, 571 nm, 656 nm, 795 nm, 978 nm and 1528 nm which are assigned to the transition from ground state 4I15/2 to the various excited levels 4F7/2, 2H11/2, 4S3/2, 4F9/2, 4I9/2, 4I11/2, 4I13/2, respectively. Surface plasmon resonance (SPR) peaks of Fe3O4 NPs were observed at 408 nm. The FTIR and Raman spectra revealed modification in network structures which is evident from wavenumber of [TeO4] and [TeO3] structural units located around 600 cm-1 and 700 cm-1, respectively. The luminescence of Er3+ ion under 375 nm excitation revealed four peaks centered at 420 nm, 460 nm, 490 nm and 516 nm which correspond to light green (4F3/2 ? 4I15/2), light green (4F7/2 ? 4I15/2), green (2H11/2 ? 4I15/2) and red (4S3/2 ? 4I15/2) emissions, respectively. The Judd-Ofelt intensity parameter, spontaneous emission probabilities, radiative lifetime and branching ratios of all transitions were calculated based on Judd-Ofelt theory. The glass magnetization in magnetic field up to 10 kOe at room temperature was found to be in the range of 0.012 – 0.052 emu g-1. The g-factor values of 1.99 to 3.06 indicate that the glass samples are paramagnetic. The result of the present work revealed that the investigated glass can be a potential material for magneto-optic devices and solid-state lasers
Transforming and sustaining SMEs Amid MCO through social media marketing: a study on Farhan Bina Teguh Enterprise
Get PDFThe purpose of this study is to investigate how the Social Media Marketing Transforming and Sustaining Smes Amid MCO, in this world of digitalization, digital marketing is a worldwide trend that used in an organization or any institutions even in education. Digital marketing refers to digital ads, such as search engines, blogs, social media, email and smartphone applications, offered by digital platforms. Amid the MCO many businesses face caused massive dislocation among small businesses just several weeks after its onset. Many businesses had temporarily closed and only essentials business operate partially or not fully capacity. This study is focus on selected SMEs company in Food and Beverages (F&B) sector which is an essential business. Mix method are used in data collection and nonprobability sampling techniques was adopted in this study. The data analysis methods are descriptive analysis, Reliability test, Normality test, Multiple Regression test and T-test analysis adopted in this research. The questionnaires were distributed through media social. The aim of the study is to explore the marketing issues on Farhan Bina Teguh Enterprise related to awareness and preferences, to analyse the consumers’ awareness and preferences through digital marketing on social media amid MCO, and to identify the relationship of consumers’ awareness and preferences towards purchase intention. This paper allows SMEs to effectively incorporate and adopt digital marketing as a tool in its business plan and to understand the competitive market effectiveness of digital marketing
Epidermal and fibroblast growth factor incorporated polyvinyl alcohol electrospun nanofibers as burn wound dressing scaffold
Get PDFThe primary concern of wound burn is a failure in wound healing and the transition to a chronic wound. Specifically, in full-thickness burn wound, even though skin autograft is the treatment of choice, it has several drawbacks in the donor site, including repeated transplanting; therefore, a robust wound dressing is still needed. Polyvinyl alcohol (PVA) is a synthetic biodegradable polymer which has been widely employed as an artificial substitute for wound dressing. Epidermal growth factor (EGF) and fibroblast growth factor (FGF) are two prominent growth factors (GFs) that mainly assist wound healing. Therefore, in this study, the incorporation of biomolecules, such as GF, into PVA matrix is deemed necessary to enhance the biological properties of the polymer. Thus, PVA-GFs biologically active scaffold for burn tissue is developed and tested on in vitro human dermal fibroblast cells (HDFs) and in vivo burn models. The scaffold design was fabricated as single, mix and multiple layers of PVA loaded with EGF and FGF by electrospinning technique. The chemical composition, morphological, surface roughness, wettability and mechanical properties of the electrospun nanofibers were characterized. The biocompatibility of different nanofiber scaffolds was assessed through in vitro cell culture with HDFs. The cell viability and attachment were analyzed by MTT assay and FESEM. The fabricated GFs incorporated PVA nanofibers were also evaluated through in vivo studies on a burn wound rat model. Sixty-three male Sprague-Dawley rats were divided into seven groups, control, burn, PVA/EGF (single), PVA/FGF (single), PVA/EGF/FGF (mix), and PVA/EGF-FGF (layers) nanofibers groups which all nanofibers set the ratio at PVA:EGF:FGF, 9.5:0.5:0.5 v/v respectively. On days 7, 14, 21, the wound closure was measured, and tissue samples were obtained, then stained with hematoxylin and eosin (H&E) stain to study the process of burn wound healing histologically. The chemical functionalities of both PVA/EGF/FGF and PVA/EGF-FGF nanofiber membranes were mainly attributed to O–H and N–H bonds. In this study, the morphology of the scaffold showed long protrusion and smooth nanofibers without beads and spray with an average range of 198 - 286 nm fiber diameter. Both PVA/EGF/FGF and PVA/EGFFGF nanofibers manifested decrement in fiber diameter, improved wettability and surface roughness. The Young’s modulus of the electrospun PVA nanofibers incorporated GFs were also observed in between 18 and 20 MPa which were in the range of preferable properties of human skin. The in vitro studies showed no cytotoxic effect of all GFs incorporated PVA nanofibers against HDFs cells and showed the highest HDFs viability and adhesion compared to the PVA control sample. Results from the in vivo studies showed that on the 21st post-burn wound day, the closure rate of the PVA/EGF/FGF and PVA/EGF-FGF nanofibers groups were visualized at 88%- 89%, respectively. The neovascular structure, sebaceous gland, and hair follicles were observed in PVA/EGF/FGF and PVA/EGF-FGF nanofibers groups and appeared more healthy skin at day 21. In conclusion, the PVA/EGF/FGF and PVA/EGF-FGF nanofibers display convergently results with superior PVA/EGF/FGF, which could be projected as a suitable biological burn wound dressing scaffold