13474 research outputs found
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Deep Q-network for just-in-time software defect prediction / Ahmad Muhaimin Ismail
No full textMitigating software defects at code level at early stages allows for long-term maintenance of software quality. According to IBM's report, the cost of fixing an error rises exponentially as software moves forward in software development lifecycle. The cost to fix defects after software release is up to 15 times more than the fixing cost for defects uncovered during the initial software development phase. Quality assurance relies on code reviews to identify and fix software defects. Apart from code optimization and formal inspection, software defect prediction makes use of limited resources as part of the code review process to identify the most cost-effective way to discover defects. A software defect prediction approach is conducted at three levels of granularity: modules, files, and changes. Change level prediction, also referred to as Just-in-Time software defect prediction, assists in reducing the amount of code coverage without inspecting the entire file or package. Nevertheless, an inaccurate model of Just-in-Time software defect prediction impedes both prevention and recovery of defects. The accuracy of prediction is mainly adversely affected by imbalanced class distributions and rate of false results. Accordingly, the focus of this study is on the problems of ineffective oversampling in imbalanced class distributions and high false-positive rates in effort-aware software defect prediction. This study proposes a reliable framework for Just-in-Time software defect prediction to accurately predict software defects during the code change process using Deep Q-Network (DQN). The proposed framework consists of two modified parts: 1) rebalancing class distribution within training datasets by kernel-based cross oversampling, and 2) using DQN as a defect classifier for accurate prediction. The proposed framework is further validated by checking the constructed prediction model for efficiency in effort cost and prediction accuracy in open-source software projects. Validation of the prediction model is performed through within-project prediction, cross-project prediction, and timewise prediction to ensure model reliability. The quality assurance team can improve software defect localization by prioritizing testing based on Just-in-Time software defect prediction
A noise filtering framework in multi-channel speech enhancement system for environmental noises / Pavani Cherukuru
No full textThe speech enhancement system deals with noisy speech signals by reducing the background noises while preventing any alterations to the speech features. Speech enhancement algorithms are used in multiple channels applied in communication devices to enhance the quality of speech signals under noisy environments known as multi-channel speech enhancement system (MCSE). Micro Electro-Mechanical Systems (MEMS) microphones are used in MCSE systems in outdoor environments. There are many existing algorithms used to filter the noise in speech enhancement systems which are frequently used as a pre-processor to enhance speech quality. These algorithms were effective in the reduction of noisy signals and improved the quality of speech. However, they may have limited ability to perform well on low Signal-to-Noise Ratio (SNR) conditions. The existing MCSE systems can filter 0 to 60dB of SNR, which gives a 62.5% Word Recognition Rate (WRR) at 0dB (considered low SNR), and 83% WRR at 60dB (considered high SNR). However, it was tested only with white Gaussian noise but not with environmental noises, which is very crucial in speech communication devices. Thus, the existing MCSE did not consider all types of noises in a real-time environment. This research aims to propose a noise filtering framework using suitable algorithm(s) for multi-channel speech enhancement systems in handling various Signal-to-Noise ratio (SNR) of environmental noises. This research firstly analyzes the findings of the existing algorithms and components involved in the Speech Enhancement and MCSE systems in handling different types of noises. This is to identify suitable algorithms for proposing a noise filtering framework for environmental noises. Secondly, experiments were conducted on the existing MCSE as the benchmark systems to analyze the limitations of the existing algorithms in handling environmental noises. From the benchmark experiments, this research has identified that the MCSE’s recognition rate reported the highest WRR at 93.77% for high SNR (at 20dB) and 5.64% for low SNR (at -10dB) on an average of five types of different noises. This research has proposed a noise filtering framework that comprises the pre-processing and deep learning algorithms for MCSE in handling various SNRs of environmental noises. The performance of the developed noise filtering framework in handling various SNR of environmental noises shows a WRR of 70.55% at -10dB SNR and 75.44 % at 15dB SNR, while 5.82 % at -10dB and 88.8% at 15dB by the existing MCSE system. It has proven that the proposed pre-processing and deep learning algorithms performed well at low SNR’s for MCSE under noisy environments
Salvage value of green buildings in Malaysia / Fiona Loo
No full textAs the market increasingly recognize the benefits of green projects and show willingness to pay a premium for them, developers are proactively presenting green sustainable construction projects as a competitive edge in the industry and to enhance their profit margins. However, most of the studies have focused on the overall value of green buildings rather than the salvage value of the green components which is one of the important components of building’s life cycle cost. Therefore, this paper aim to develop a framework for salvage value of green components for the use by property and estate valuers and quantity surveyors. The objective of this study is to identify the green components ideal for Malaysia’s tropical environment. And also determining factors contribute to the condition of salvage value of the green components and then analyzing the salvage value of green components. The study involves a literature review of academic and draws on data relating to green components in green building, International green rating tools and salvage value. Using a quantitative methodology, this study sent 213 sets of questionnaire questionnaires to quantity surveyors, estate agents, and property valuers. But just 166 sets, or 77.9%, got a response. To ascertain the optimal green components for Malaysia's tropical climate, factors influencing the condition of green components, and the floating of salvage value of green components, mean analysis and Relative Important Index analysis were performed. In Malaysia's humid and hot atmosphere, the popularity of passive daylighting and natural ventilation techniques highlights their benefits. The length of time a green component is used and its proximity to disposal restrictions stand out as the most critical factors affecting green component's condition. In the result, the findings of this research paper could be beneficial to the construction industry by recognizing the hidden cost or value of assets after their useful life and taking building life cycle costing into account
Perception and production of L2 Mandarin stop consonants by Malaysian Malay speakers / Magdalene Vethanayagam James
No full textLimited studies have been done on second language acquisition in the Mandarin language by Malaysian Malay learners. Therefore, the current study addressed this literature gap by systematically describing Mandarin stop consonant acquisition among Malaysian Malay learners. To ascertain whether Malaysian Malay learners have difficulty perceiving and producing Mandarin voiceless unaspirated and aspirated stops, this study examined the perception and production of L2 Mandarin stop consonants as well as the L2 acquisition of Mandarin unaspirated and aspirated consonants. Ten Mandarin teachers whose first language is Malay participated in this research. The two main data sources of this research were a perception task and a production test. The purpose of the perception task was to test whether Malaysian Malay learners perceptually contrast Mandarin aspirated stops from unaspirated stops by making the participants listen to 24 words and write down pinyin. The results showed that out of 240 tokens (24 x 10), only four errors occurred. This indicates that Malaysian Malay speakers can accurately perceive voiceless aspirated and unaspirated stop consonants. On the other hand, the purpose of the production task was to enable Malaysian Malay learners to differentiate aspirated Mandarin stop consonants from their unaspirated counterparts during the production of Mandarin stop consonants in terms of voice onset time (VOT) values. For this task, the participants read 40 Mandarin words. Based on the analysis of VOT, the most difficult consonants for the participants to produce were /p/, while the easiest consonants for the participants to produce wer
Fish skin as an alternative biopolymer towards the development of ion conducting green solid electrolytes impregnated with ammonium nitrate / Norlin Nadzrin
No full textIn this study, new sequences of fish gelatin (FG) as polymer host for solid polymer
electrolytes (SPE) impregnated with ammonium nitrate (NH4NO3) are prepared via
solvent-casting method. Chitosan (CS) was blended with FG to provide extra pathways
for protonic migration to boost up the conductivity. From FESEM micrographs, the blend
of 60 wt. % FG and 40 wt. % CS, (CF4) are found to be miscible to one and another and
from XRD analysis it is confirmed that the ratio is the most amorphous with the lowest
degree of crystallinity ~ 15. 38 %. The most amorphous electrolyte in the salted single
polymer system is found to be FG25 and that of the salted blended system, is CFs40. The
interactions between the material have been determined from the band shifts and changes
of the peak’s wavenumber from FTIR spectroscopy analysis. The ionic conductivity of
pure FG film has been identified to be 1.17 × 10-10 S cm-1 and optimised at 1.52 × 10-5 S
cm-1 with the inclusion of 25 wt. % NH4NO3. The value has increased to 1.61 × 10-3 S
cm-1 with the addition of 40 wt. % NH4NO3 in FG-CS polymer electrolytes system. The
temperature dependence conductivity plot is Arrhenian. The variation in conductivity is
accompanied by the changed in surface morphology as can be observed from FESEM
analysis. Transport analysis showed that the trend in conductivity can be influenced by
the mobility (μ), the diffusion coefficient (D) and number density (n) of ions. TGA and
DSC are discussed to study the thermal properties of the electrolytes. The degradation
temperature and glass transition temperature decreased as salt is added into the system
due to the complexation of salt and the polymer. Tg decreased to 54.83 °C in FG25 and
to 83.33 °C in CFs40. From TNM analysis, ions were found to be the dominant charge.
tions values in the highest conducting electrolytes are 0.92 and 0.96 in FG25 and CFs40,
respectively. LSV result confirms the suitability for the highest conducting electrolyte
with ~2.6 V for both salted systems
Caries preventive effect and cost effectiveness of community water fluoridation in Malaysia / Susan Shalani Gnanapragasam
No full textBackground: Community water fluoridation (CWF) coverage in Malaysia has declined since 2014 due to its discontinuation in Pahang state over financial constraints, resulting in an increased caries prevalence among Pahang schoolchildren. Despite Malaysia's long history of the CWF programme, there is limited knowledge about the rate of caries progression among schoolchildren who received full or partial exposure to CWF (prior to its cessation) and the cost effectiveness of CWF. Aim: To evaluate the caries preventive effect in the permanent dentition of primary schoolchildren from 2015 to 2019 and cost-effectiveness of CWF in the prevention of caries in Malaysia from a healthcare provider perspective. Methods: This study was divided into two phases, with phase I employing a retrospective cohort study design using secondary data analysis involving school dental records of primary schoolchildren. These schoolchildren were followed up retrospectively from 2015 (8 years old) to 2019 (12 years old) in Pahang (partial exposure to CWF) and Perak (full exposure to CWF) states with caries experience recorded using the Decayed Missing Filled (DMF) index. Data were analysed using descriptive and inferential statistics with SPSS 21.0 software. Phase II involved an economic evaluation based on retrospective expenditure data of CWF programme in Perak over five years, along with caries-related treatment data from school dental records in both states. CWF effectiveness was based on the mean caries increment data obtained from Phase I in both states. Analysis was conducted from the healthcare provider perspective, with costs presented in 2015 Malaysian Ringgit (MYR). The incremental cost-effectiveness ratio (ICER) was estimated as cost per dental caries prevented. Data in phase II were analysed descriptively and inferentially using Microsoft Excel 2019 and SPSS 21.0. Results: The sample consisted of 462 school dental records in both states. The mean caries increment and cumulative caries incidence among primary schoolchildren in Pahang was significantly higher compared to Perak from 2015 to 2019. Over the five years, the mean caries increment and cumulative caries incidence in Pahang were 0.83 and 32.8%, respectively, compared to Perak, where the corresponding values were 0.18 and 11.5%. The associated risk factors for mean caries increment included type of CWF exposure, preventive dental treatment status, and baseline caries in 2015. For cumulative caries incidence, the associated risk factors were type of CWF exposure and preventive dental treatment status. The cost per capita for CWF among primary schoolchildren in Perak was estimated at MYR 6.30. Over five years, mean caries-related treatment costs were significantly higher in Pahang (MYR 79.71) compared to Perak (MYR 14.04) among the primary schoolchildren. The CWF programme had an ICER of MYR -91.35 per dental caries prevented. Conclusion: This study demonstrated significant caries increment and incidence in permanent dentition among primary schoolchildren in Pahang after CWF ceased. The findings also indicated that the continuation of the CWF programme in Perak’s public water supplies was cost effective for the schoolchildren. These results provide valuable insights for policymakers to support CWF continuation in Malaysia and emphasize the need for reimplementation in the affected state
Exploring molecular recognition between an anti-neoplastic drug, floxuridine, and human serum albumin through spectroscopic, computational and atomic force microscopic approaches / Fazal Rehman
No full textThe binding mode of antineoplastic antimetabolite, floxuridine (FUDR), with human serum albumin (HSA), the leading carrier in blood circulation, was ascertained using multi-spectroscopic, microscopic, and computational techniques. A static fluorescence quenching was established due to decreased Ksv values with rising temperatures, suggesting FUDR-HSA complexation. UV-vis absorption spectral results also supported this conclusion. The binding constant, Ka values, were found within 9.6−7.9 103 M−1 at 290, 300, and 310 K, demonstrating a moderate binding affinity for the FUDR-HSA system. Thermodynamic data (Sº = +46.35 J.mol−1.K−1 and, Hº = −8.77 kJ.mol−1) predicted the nature of stabilizing forces (hydrogen-bonds, hydrophobic, and van der Waals interactions) for the FUDR-HSA complex. Circular dichroism spectra displayed a minor disruption in the protein’s 2o and 3o structures. At the same time, atomic force microscopy images proved variations in the FUDR-HSA surface morphology, confirming its complex formation. The protein's microenvironment around Trp/Tyr residues was also modified, as judged by 3-D fluorescence spectra. FUDR-bound HSA showed better resistance against thermal stress. As disclosed from ligand displacement studies, the FUDR binding site was placed in subdomain IIA (Site I). Further, the molecular docking analysis corroborated the competing displacement studies. Molecular dynamics evaluations revealed that the complex achieved equilibrium during simulations, confirming the FUDR–HSA complex's stability
Relationship between air quality status and respiratory health among preschoolers AT Johan Setia and Kuala Selangor / Shamili Nair Ravindran Nair
No full textPoor air quality in Johan Setia can be unhealthy and negatively affect sensitive groups like children and elderly. Long-term and short-term exposure towards sensitive groups could decline lung function and steer to chronic lung diseases. The aim of this research is to address the baseline of respiratory health status of pre-schoolers in relationship to the exposure to relatively concentrated air pollutant within specified duration. The study location was carried out at Johan Setia, where it surrounded by large scale industrial sectors. Collected information were later compared to the data collected from the District of Kuala Selangor where it represents the control site. The objectives of the research are to determine the correlation between preschoolers’ respiratory health and changes in the core index value of PM10 and PM2.5 in the ambience. The duration of air quality data from the year 2018, 2019 and 2020 were collected from DOE AQ Monitoring Station
as the independent variable meanwhile the health status of preschoolers was used as dependent variable. Information was collected using survey instrument, with guided questionnaires. Beside health status, the survey also included parent’s knowledge, attitudes and practises (KAP) towards air quality. Data analysis for PM10 and PM2.5 in Johan Setia shown exceeding the standard annual range. While other pollutants such as ozone (O3), carbon monoxide (CO), sulphur dioxide (SO2), and nitrogen dioxide (NO2) remained within standard range. This study has revealed that there is relationship between children exposed to high PM reading with the occurrence of symptomatic respiratory health. Analysis of KAP is to be disclosed at the end of this study
Study of poly (acrylic acid) and lithium tetrafluoroborate/lithium perchlorate based polymer electrolytes / Ngai Koh Sing
No full textPolymer electrolytes are among the most potential materials used in electrical double layer capacitor and thus the characteristics of these electrolyte exert great impacts on the performance of the electrochemical devices. In this study, four types of poly(acrylic acid)-based electrolytes were synthesized via solvent casting, namely poly(acrylic acid)/lithium tetrafluoroborate, poly(acrylic acid)/lithium tetrafluoroborate/barium titanate, poly(acrylic acid)/lithium perchlorate, and poly(acrylic acid)/lithium perchlorate/barium titanate. The physicochemical properties such as ionic conductivity, structural and thermal stability were evaluated by electrochemical spectroscopy, themogravimetric analysis, X-ray diffraction and fourier transform infrared analysis.
Poly(acrylic acid) (PAA) managed to host up to 30 wt.% of LiBF4 and exhibit the highest conductivity of 6.61 × 10-4 S cm-1. The ionic conductivity of 8.95 ×10−4 S cm−1 is obtained after 10 wt.% of BaTiO3 was added in PAA/LiBF4. The incorporation of 10 wt.% LiClO4 in the PAA matrix demonstrated a highest ionic conductivity, which is 2.40 × 10−6 S cm−1. The ionic conductivity of 1.0 × 10−5 S cm-1 was obtained for PAA-LiClO4-BaTiO3 electrolyte. Arrhenius equation was employed to examine the effects of temperature on the ionic conductivity of the polymer electrolytes. The results shown that all the electrolyte systems obey Arrhenius theory where the ionic conductivity is corresponded to the elevation of temperature. The variation of dielectric constant values with frequency in PAA-based electrolyte systems confirm the presence of polarization process at electrode interface. The variation of dielectric constant with frequency is more prominent with the effect of conducting salt or dopant addition. In the addition of more conducting salt into PAA electrolyte matrix, the loss tangent peaks shift towards higher frequency suggesting the speed up of relaxation time.
Polymer electrolytes with wide electrochemical stability window (ESW) are potentially to be applied for electrochemical devices. PAA-LiBF4 and PAA-LiBF4-BaTiO3 electrolyte demonstrated ESW at 3.2 V and 4.0 V respectively. However, the electrolyte systems using LiClO4 as conducting salt portrays a wider ESW which are about 10.0 V and 11.5 V for PAA-LiClO4 and PAA-LiClO4-BaTiO3, respectively. The study confirmed that incorporation of conducting salt of LiBF4/LiClO4 and BaTiO3 improves the thermal stability of polymer electrolyte. The XRD study indicates that higher loading of LiBF4/LiClO4 and BaTiO3 indicates a higher degree in amorphous nature which improves the ionic conductivity in the PAA electrolytes. The FTIR study showed evident on the interaction between Li+ and PAA.
The characterization study indicates that all the polymer electrolyte prepared in my study can be used as promising electrolyte materials for EDLC application especially the PAA-LiClO4 based electrolytes with excellence electrochemical stability window
Dynamics of ecosystem carbon stock in different age stands of planted mangrove forests in Peninsular Malaysia / Tan Junheng
No full textMangrove forests are important carbon sink. They are popularly known today as coastal blue carbon ecosystem together with seagrass beds and salt marshes. The carbon stored in the forest help to mitigate climate change. The aim of the study is to assess the total ecosystem carbon stocks (TEC) in different aged (5, 9, 16, 21 and Intact) at planted mangrove forests. The study was conducted in Nibong Tebal and Juru, Penang as there are mangrove plantation projects which have recorded age. In order to determine whether that the age of the mangrove plantation have an influence on the ecosystem carbon stock, the vegetative biomass (aboveground biomass and belowground biomass), dead and down wood, litter and soil samples were examined for their biomass and carbon stocks. Diversity indices, CO2e and carbon market value were also assessed in this study. The 21-year-old plantation has the highest yield of TEC which is 786.49 Mg C ha-1. Results showed that the TEC of the mangrove forest increases with age (P<0.05). Species diversity for this experiment was also taken for this study. However due to lack of mangrove tree species in the sample areas, we have determined that species diversity does not affect the TEC rather the IVI influences the TEC(P<0.005). To highlight the importance of mangrove plantations, the estimated economic value of carbon stocks was applied for this study. This shows that the mangrove plantations are important for the carbon market as the forest ages which helps to store more carbon