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An efficient DDoS attack detection framework for vehicular communication / Raenu Kolandaisamy
No full textVehicular Ad Hoc Networks (VANETs) are rapidly gaining attention due to the diversity of
services that they can potentially offer. VANET is a wireless network that allows vehicles to
interconnect and communicate with other nearby vehicles and Road Side Units (RSUs). In
VANET, each vehicle is considered as a node which is equipped with an On-Board Unit
(OBU) and an Application Unit (AU). The nodes may connect and communicate with each
other directly (i.e., Vehicle to Vehicle (V2V)) or through RSUs (i.e., Vehicle to Infrastructure
(V2I)). This is primarily for alleviating an Intelligent Transport System (ITS) that aims to
provide a wide range of applications and services including safety, non-safety, and
infotainment. The aim of this research is to enhance the detection of DDoS attacks on
vehicular communication in VANET environments. This enhanced detection of DDoS attack
will provide secure and safe vehicular environment for the drivers and passengers to access
the VANET applications and services without having to face disturbance or unavailability of
services. However, VANET communication is vulnerable to numerous security threats such
as Distributed Denial of Service (DDoS) attacks. Dealing with these attacks in VANET is a
challenging problem. Most of the existing DDoS detection techniques suffer from higher
detection time. To overcome these problems, we present an efficient DDoS attack detection
framework which consists of important techniques, i.e. MVSA and SPPA. During V2V
communication, DDoS attacks may occur without the users/drivers realizing or being fully
aware about it. In the MVSA model we consider small scale vehicular environments. The MVSA model maintains the multiple stages for the detection of DDoS attacks in vehicular
networks. The model observes the traffic in different situations and time frames and
maintains different rules for various traffic classes in various time windows. In the SPPA
model, a cluster-based attack detection in data collection was considered, where the leaf
nodes pass the sensitive information to the cluster head. The existence of malicious nodes
threatens decision making by sending malicious information and sometimes sending many
packets to the vehicle node. To overcome this issue, a Stream Position Performance Analysis
(SPPA) model has been proposed. This model is used for big scale vehicle environments.
This approach monitors the position of any field station in sending the information to perform
a Distributed Denial of Service (DDoS) attack. The performance of the MVSA and SPPA
methods is evaluated using a Ns2 simulator. Simulation results demonstrate the effectiveness
and efficiency of the MVSA and SPPA regarding attack detection time and reducing the
impact on vehicular communication on VANET
An intra-severity classification and adaptation technique to improve dysarthric speech recognition accuracy / Bassam Ali Qasem Al-Qatab
No full textDysarthria is a motor speech impairment at the neurological and/or muscular levels that caused difficulty in pronouncing words clearly. Automatic speech recognition (ASR) system is increasingly applied as assistive technology to aid an individual with physical disability particularly the speech impaired community such as dysarthria speakers. However, the development of an effective ASR system is hindered by the data sparsity, either in the coverage of the language or the size of the existing speech databases. The speaker adaptation (SA) technique is one of the solutions to overcome the data sparsity issue of ASR for dysarthric speakers. Our proposed method introduces the intra-severity classification and adaptation techniques which are applied sequentially in two stages of system development. Firstly, intra-severity classification intended to identify the level of severity of the dysarthric speakers. Secondly, the identified severity level of a particular dysarthric speaker in the first stage is applied to the corresponding intra-severity adaptation of dysarthric speech. For the classification part, there are six algorithms used to classify the intra-severity of dysarthric speakers. The algorithms include Linear Discriminant Analysis (LDA), Artificial Neural Network (ANN), Support Vector Machine (SVM), Naive Bayes (NB), Classification And Regression Tree (CART), Random Forest (RF). The Random Forest (RF) algorithm was proposed as a classifier for the intra-severity classification of the dysarthric speaker which has the lowest average ranking score as compared to other benchmark classifiers. The intra-severity adaptation of the ASR system was developed using two well-known adaptation techniques which are the Maximum Likelihood Linear Regression (MLLR) and Maximum A Posterior (MAP) as well as a combination of them. The results showed that the combination of MLLR+MAP adaptation outperforms all adaptation techniques with total improvement in Word Error Rate (WER) from 39.84% to 18.48% with 53.61% improvement from the baseline WER in the overall performance of the system. The total improvement of the WER based on severity level were 66.32%, 52.35%, and 45.20% for mild, moderate, and severe severity level respectively for the hybrid MLLR+MAP adaptation technique. The combination of the adaptation techniques in sequential order helps to take advantage of each adaptation technique and avoid the flaws of each technique in relation to adaptation data size
Pembangunan modul pedagogi komunikasi nonverbal al-Quran dalam pengajaran bahasa Arab / Mohd Ala-Uddin Othman
No full textKajian ini bertujuan membangunkan Modul Pedagogi Komunikasi Nonverbal al-Quran
(MPKNVQ) berasaskan model ADDIE yang telah diubahsuai. Objektif kajian ialah untuk (i)
mengenal pasti komunikasi non-verbal al-Quran untuk pengajaran dan pembelajaran Bahasa
Arab, (ii) Mengenal pasti reka bentuk MPKNVQ yang dibangunkan untuk pengajaran BA,
(iii) membangunkan MPKNVQ (iv) menilai keberkesanan MPKNVQ dari aspek sikap,
motivasi dan pencapaian pelajar terhadap pengajaran dan pembelajaran BA. Kajian ini adalah
kajian rekebentuk dan pembangunan yang melibatkan 3 fasa utama iaitu (a) fasa analisis
keperluan berdasarkan kajian literatur dan analisis dokumen. Ayat-ayat Quran telah dianalisis
dan disaring berdasarkan 10 saluran nonverbal untuk pengajaran yang dinyatakan oleh
Richmond dan McCroskey (2000) (b) fasa kedua melibatkan proses mereka bentuk dan
membangunkan MPKNVQ menggunakan teknik Delphi ubahsuaian dua pusingan. 17 orang
pakar terlibat untuk menentukan saluran KNV yang sesuai dalam pengajaran BA. Ujian
Wilcoxon (Wilcoxon Signed-rank Test) telah digunakan untuk melihat aras konsistensi antara
persetujuan pakar dalam pusingan pertama dan kedua, dan (c) fasa ketiga adalah fasa
pelaksanaan dan penilaian keberkesanan dengan menggunakan kaedah soal selidik dan ujian
pencapaian bagi mengetahui tahap sikap, motivasi dan pencapaian. Kaedah kuasi eksperimen
yang melibatkan 2 kumpulan iaitu kumpulan rawatan seramai 22 orang dan kumpulan kawalan
seramai 28 orang telah dijalankan selama 12 minggu. Ujian-t telah dijalankan bagi menguji
tahap sikap, motivasi dan pencapaian untuk melihat perbezaan antara kumpulan rawatan dan
kumpulan kawalan. Dapatan fasa pertama menunjukkan di dalam al-Quran terdapat 8 sub
saluran penampilan fizikal, 19 sub isyarat gerakan anggota badan, 13 sub saluran ekspresi
wajah, 12 sub saluran okulesik, 15 sub saluran vokalik, 13 sub saluran proksemik, 6 sub
saluran haptik, 9 sub saluran persekitaran, 4 sub saluran olfaktik dan 7 sub saluran kronemik.
Dapatan fasa kedua menunjukkan tiada perbezaan signifikan bagi jawapan panel pakar dan
membuktikan konsistensi jawapan panel pakar bagi kedua-dua pusingan. Dapatan fasa ketiga menunjukkan Modul Pedagogi Komunikasi Nonverbal Al-Quran (MPKNVQ) dapat
meningkatkan tahap sikap, motivasi dan pencapaian. Kajian ini telah berjaya membangunkan
sebuah modul MPKNVQ yang mampu meningkatkan tahap sikap, motivasi dan pencapaian
pelajar dalam pengajaran dan pembelajaran Bahasa Arab
The effects of task complexity and task condition on L2 individual writing and peer interaction / Soh Siak Bie
No full textThis study adopts the Cognition Hypothesis to examine the effects of task complexity, (+/- causal reasoning demand) and task condition (individual, dyadic and triadic groupings) on the L2 individual writing and peer interaction. A 2 (Task Complexity) x 3 (Task Condition) repeated-measures ANOVA (RM-ANOVA) research design, was employed on 36 Malaysian university students. Six argumentative topic-based written texts were produced by each participant in each of the three sessions. In each of the sessions, i.e. individual, dyadic and triadic, participants experienced two argumentative tasks: one simple and another complex based on the principle of natural complexity progression. The individual session was set as baseline data to compare results of the Second Language (L2) individual writing and peer interaction in dyadic and triadic conditions. For the dyadic and triadic sessions, participants first discussed each of the simple and complex topics given and then proceeded to write on each topic individually. In total, 216 written texts were analysed for lexical and syntactic Complexities, morphosyntactic Accuracy and Fluency (CAF) while transcripts of interaction totalling 15 hours were analysed in terms of Negotiation of Meaning (NoM), Language-Related Episodes (LREs) and uptakes of recast. Results of CAF on the L2 individual written production revealed that task complexity is statistically significantly different for certain dimensions of lexical and syntactic complexities, accuracy, text length but not for fluency. Task condition on the other hand, is statistically significantly different for the measures of lexical and syntactic complexities except for certain dimensions of complexities, like coordinate clause per T-unit, and accuracy, error-free clauses (EFC). For L2 individual writing, tasks that are more complex produced lengthier texts with higher accuracy, EFC and greater syntactic complexity, for mean length of clause (MLC), but not for dependent clause per clause (DCC). As for task condition, triadic grouping produced lengthier texts with higher lexical complexity, for mean segmental type/ token ratio-50 (MSTTR-50) and greater syntactic complexity, for MLC. As for the measure of DCC, dyadic grouping produced dependent clauses that are more varied in the simple task. The baseline data of the individual session produced more fluent L2 individual writing, as compared to dyads followed by triads. Results of the measures of NoM, LREs and Uptakes on the peer interaction revealed that L2 learners in triadic grouping produced higher comprehension checks when negotiating meaning with peers. It also showed that dyadic grouping produced higher partially or incorrectly resolved LREs and unmodified uptakes of recast. In conclusion, the findings lent partial support to Robinson’s Cognition Hypothesis that cognitively more complex tasks increased the L2 production of certain dimensions of lexical and syntactic complexities, like MSTTR-50, MLC and accuracy, EFC. As for the finding of the dimension of syntactic complexity, DCC, it seemed to have a trade-off effect as proposed by Skehan’s Trade-off Hypothesis. Task condition with more number of participants assigned for peer interaction prior to L2 learners’ individual writing seemed to contribute to higher MSTTR-50, MLC and EFC
Kesan kemahiran pemprosesan fonologi terhadap pembacaan awal kanak-kanak tri bahasa / Loo Fung Lan
No full textKemahiran pemprosesan fonologi merupakan kemahiran yang diperlukan dalam pemprosesan bahasa lisan dan bertulis dengan menggunakan maklumat fonologi. Kepentingan kemahiran pemprosesan fonologi dalam pembacaan awal bukan terhad kepada bahasa berabjad seperti Bahasa Inggeris, tetapi juga menyumbang kepada bahasa bukan berabjad seperti Bahasa Cina. Kajian ini bertujuan mengkaji tentang kesan kemahiran pemprosesan terhadap pembacaan awal kanak-kanak dalam tiga bahasa iaitu Bahasa Cina (L1), Bahasa Inggeris (L2) dan Bahasa Melayu (L3). Kajian ini melibatkan seramai 150 orang kanak-kanak Cina berumur enam hingga tujuh tahun dari enam buah Sekolah Rendah Jenis Kebangsaan Cina di Selangor, Malaysia. Sampel diuji dengan set ujian yang menilai keupayaan kemahiran pemprosesan fonologi dan prestasi pembacaan awal kanak-kanak dalam Bahasa Cina, Bahasa Inggeris dan Bahasa Melayu. Tiga kemahiran pemprosesan fonologi diukur, iaitu kesedaran fonologi (PA), ingatan fonologi (PM) dan penamaan automatik pesat (RAN). Data dianalisis dengan menggunakan analisis model persamaan struktur (SEM) dengan pendekatan PLS (Partial Least Square). Dapatan kajian menunjukkan PA merupakan peramal yang paling kuat untuk meramalkan prestasi pembacaan awal Bahasa Inggeris (β = .535, p < .001) dan Bahasa Melayu (β = .844, p < .001), manakala RAN peramal yang paling kuat untuk meramalkan prestasi pembacaan awal Bahasa Cina (β = .334, p < .001). PA Bahasa Melayu memberi kesan positif dan signifikan terhadap pembacaan awal Bahasa Melayu (β = .853, p < .001), Bahasa Cina (β = .779, p < .001) dan Bahasa Inggeris (β = .688, p < .001). Ini menunjukkan pemindahan kemahiran terbalik berlaku (L3 L1 dan L3 L2). Di samping itu, PM dan RAN Bahasa Inggeris memberi kesan positif dan signifikan terhadap pembacaan awal Bahasa Cina (β = .373, p < .05; β = .538, p < .001) dan Bahasa Melayu (β = .374, p< .05; β = .401, p < .001) menunjukkan pemindahan kemahiran antara bahasa berlaku (L2 L1 dan L2 L3). Selain itu, analisis perantara (mediation analysis) menunjukkan bahawa Bahasa Inggeris memberi kesan perantara penuh terhadap hubungan antara Bahasa Cina dan Bahasa Melayu. Bahasa Inggeris adalah agen yang memudahkan pemerolehan pembacaan awal Bahasa Melayu bagi kanak-kanak berbahasa Cina. Model struktural kajian dibina untuk memaparkan pengaruh kesan keseluruhan pembacaan awal kanak-kanak antara tiga bahasa. Akhir sekali, analisis IPMA (Importnace-performance matrix analysis) menonjolkan keperluan untuk meningkatkan kesedaran fonologi kanak-kanak dalam Bahasa Inggeris. Kajian ini telah menampilkan kepentingan pemprosesan fonologi terhadap kejayaan pembacaan awal kanak-kanak dalam tiga bahasa
Student interaction, attitudes and perceptions in online collaborative writing / Husna Fatimah Mohd Ghazali
No full textStudents’ perceptions towards online learning are significant as today’s students have high expectations in their learning environment, which initially brings forth their willingness to cooperate during the engagement process. The study focuses mainly on students’ attitude and perceptions towards online collaborative writing tasks, which indicate their preference in learning. Students’ online interactions play an important role to determine if online community is able to achieve its goal. The objectives of this study are to determine students’ attitudes towards online collaborative writing, analyse students’ attitudes while interacting in online collaborative writing, and identify students’ perceptions towards online collaborative writing. The findings from the questionnaire show positive results were meeting the individual needs of each student are crucial for them to become active, independent, alert and able to be effective learners. Positive students interactions will go beyond the classroom, good communication skills that the students learn from interactions will benefit them to develop learning and students’ perception of online collaborative writing proves to be positive and encouraging. In this study, social online interactions may have affected the students’ attitude and perceptions of their collaborations. The qualitative findings on four elements; exchanging ideas, clarifications, question, and compromising during online interaction showed a positive outcome. This study suggests for future research to explore more on the qualitative outlook of group interactions for peer feedback and the students’ attitudes towards online collaboration authority in the product. It is in the hope of improving perceptions and satisfaction a much better learning environment can be developed
Conceptions and practices of divergent thinking among form two science teachers / Lakshmi Nair Krishnan Kutty
No full textThe purpose of this study was to investigate the conceptions and practices of Divergent Thinking among Form Two Science Teachers. Divergent thinking is integral to creativity which comprises four components, namely Fluency, Flexibility, Originality and Elaboration. Divergent thinking is important because it is the thought process that allows students to think outside the norm and to create many, original solutions for new problems. In our education system, it is the teachers’ responsibility to foster divergent thinking in classroom as teachers are the main mediators between the curriculum and classroom practices. If the teachers lack conceptions on divergent thinking, they might unknowingly foster or suppress divergent thinking among students. The study was carried out based on three objectives, (i) to investigate selected Form Two science teachers’ conception about divergent thinking; (ii) to investigate Form Two science teachers’ practices of divergent thinking in science classroom; and (iii) to describe what are the gaps (if any) between Form Two science teachers’ conceptions and practices of divergent thinking in science classroom. Three Form Two science teachers were selected based on convenience from three different secondary schools in Kuala Lumpur to participate in this study. The study utilized an exploratory qualitative research design. Data collection method involved interview sessions with teachers and classroom observations. An observation guide comprising of ten items based on four elements: Fluency, Flexibility, Originality and Elaboration was prepared. It was used as a framework to analyze classroom observation, discourse and conceptions by using Constant Comparative Method (CCM). Through the process of coding segments of interview texts and items from observation guide, ten categories were elicited. The trustworthiness of this study were ensured by Expert verification, Member Checking, and peer review. Findings of this study revealed that teachers do have some common conceptions pertaining divergent thinking; which were (i) many ideas, (ii) thinking out of the box, and (iii) producing uncommon or extraordinary outcomes. However, with only three teachers, their practices seem to lie along a continuum. Analysis of gaps showed that one of the teachers showed almost no gap as her conceptions and practices of divergent thinking were mostly parallel. On the other hand, the other two teachers have wider gaps, such as having the conception but unable to practice it, or vice-verse. According to the Theories-of-Action, when conceptions are not parallel as practices, problem would arise. Therefore, educational policies and teacher education programs should take steps to bridge the gaps if teachers are to successfully implement divergent thinking in the science classrooms
Kemahiran membaca teks bahasa Tamil dengan penggunaan Comic Strips dalam kalangan murid tahun empat / Shanthini Sree Mathialathan
No full textPenggunaan Comic Strip sebagai bahan bacaan teks bahasa Tamil mampu mewujudkan suasana pembelajaran yang menyeronokkan. Comic strip berperanan sebagai alat yang berfungsi untuk menyampaikan isi pembelajaran yang mana ia mewujudkan satu proses komunikasi antara murid dengan bahan pembelajaran. Kajian ini merupakan sebuah kajian tindakan yang melibatkan murid tahun empat dalam membaca teks bahasa Tamil dengan menggunakan comic strip.Reka bentuk kajian ini adalah bentuk kualitatif yang menggunakan kaedah pemerhatian, temu bual dan analisis dokumen yang mana kaedah pemerhatian digunakan sebagai instrumen utama dan kaedah temu bual dan analisis dokumen sebagai instrumen kedua dalam pengumpulan data. Dalam kajian ini, kemahiran membaca teks bahasa Tamil murid tahun empat akan dinilai melalui Comic Strips dengan penggunaan aplikasi storyboard that. Semasa kajian ini dijalankan, kaedah pemerhatian akan digunakan terhadap sampel yang terlibat. Sampel yang terlibat adalah empat orang murid tahun empat. Pada masa yang sama penyelidik juga akan menemu bual dua orang guru untuk mengukuhkan lagi data yang bakal diperolehi. Kajian ini dijalankan di sebuah sekolah yang terletak di negeri Selangor. Kajian ini merangkumi beberapa cadangan untuk berkhidmat sebagai panduan untuk kajian masa depan. Semoga menerusi kajian ini diharap kualiti pembelajaran Bahasa Tamil dapat ditingkatkan
Polymicrobial interactions between selected microbes of oral biofilm and differential expression of ALS genes and their related proteins / Ayesha Fahim
Get PDFMore than 700 different types of microorganisms dwell in human oral mucosal
surfaces. The interactions between these microorganisms contribute to formation of
polymicrobial communities on hard and soft tissues as well as on dentures and implants.
Candida albicans, a pleomorphic fungus inhabiting oral and gastrointestinal (GIT)
mucosa becomes pathogenic in favourable conditions causing local or systemic disease.
Since streptococci are early colonisers, the ability of Candida albicans to adhere to
streptococci paves the way for an additional surface for candidal colonization and
propagation. This study was aimed to investigate polymicrobial interactions between C.
albicans, S. sanguinis and S. mitis on in-vitro oral biofilms and to identify differential
expression of agglutinin-like sequence ALS1, ALS2, ALS3 genes and associated proteins.
Single, dual and mixed species oral biofilms were formed in-vitro in static and dynamic
flow conditions for 24 h. Biomass of each biofilm was determined using crystal violet
(CV) stain and the cellular metabolic activity within these biofilms was assessed using
tetrazolium XTT assay. Microbial growth of biofilms was calculated by counting colony
forming units (CFU) on continuous flow model. The morphology of organisms in these
biofilms was viewed under scanning electron microscope (SEM) and analysed using
morphology index (Mi). The antimicrobial effect of amphotericin B, nystatin and
chlorhexidine on each biofilm was seen by determining minimum inhibitory
concentration (MIC). The expression of target genes in C. albicans was analysed by
quantitative real-time PCR (qPCR) while their respective proteins by Western blot
technique. CV and XTT analysis of static biofilms showed a significant increase in
biomass and cellular metabolic activity of two dual species and mixed species in
comparison to single species biofilm. The results were validated by CFU count of
microorganisms on biofilms formed under continuous nutrient flow. SEM analysis
revealed candida hyphae formed under the influence of streptococci in dual and mixed
iv
species biofilm, whereas, only blastoconidia were visible in single species. The MIC
values of amphotericin B (AmB), nystatin (Nt) and chlorhexidine (CHX) was 4µg/mL
against single species whereas the values were higher against dual and mixed species (64
and 125µg/mL respectively for AmB) (32 and 125µg/mL for Nt) (4 and 32µg/mL for
CHX). The genomic expression revealed that ALS1 and ALS3 were significantly over
expressed in mixed species biofilm, in comparison to dual species and single species
biofilm. However, ALS2 was not significantly expressed in dual or mixed species.
Western blot of single species showed clear bands of als1, als2 and als3p whereas, in dual
and mixed species clear bands of only als1 and als3p were visible. In conclusion, C.
albicans demonstrated enhanced biofilm characteristics when grown with S. mitis and S.
sanguinis in both static and dynamic flow conditions. The role of ALS1 and ALS3 genes
is enhanced in dual and mixed species. This study proposes substantial contribution of
bacteria in propagation of C. albicans biofilm. Hence, in oral fungal infestations,
promotion of the infection may be contingent upon the bacterial constituent, a prospect
which is frequently neglected and requires more research
Evaluation and inter-comparison of satellite precipitation estimations for extreme flood events in Peninsular Malaysia / Eugene Soo Zhen Xiang
Get PDFSatellite precipitation products (SPP) have been useful in any hydrological applications as their extensive spatial coverage and finer space and time resolutions. However, these satellite estimations exhibit large systematic and random errors which may cause large uncertainties in any hydrological applications. In this study, three advanced satellite precipitation products, i.e. CMORPH, TRMM 3B42V7, and PERSIANN are utilized in conjunction with the ground observation to investigate their performance in detecting rain, capturing storms and rainfall pattern during extreme flood events. This study evaluates and compares the capability of the SPP by focusing on the 2014-2015 northeast monsoon extreme flood events. Three affected river basins, i.e. Kelantan (13,100 km2), Johor (1,652 km2) and Langat river basin (2,350 km2) are chosen as study areas. Firstly, to compare with the grid-based satellite estimations, a validation between five spatial interpolation methods (Arithmetic Mean (AM), Thiessen Polygon (TP), Inverse Distance Weighting (IDW), Ordinary Kriging (OK), and Spline (SP)) with ground observations is done whereby the result shows that none of the spatial interpolation methods is superior to the others. Furthermore, the result shows that all three SPP have performed reasonably well for the Kelantan river basin whereas for the other two river basins, only TRMM and CMORPH perform better. As these SPP exhibit biases, the three widely used approaches of bias correction, namely Linear Scaling (LS), Local Intensity Scaling (LOCI) and Power Transformation (PT) are applied on the daily SPP to improve the estimations. Bias correction analysis is performed using the aforementioned methods to the Langat river basin only. Findings indicate that the LS scheme is able to match the mean precipitation of every SPP but does not correct the standard deviation (SD) and coefficient of variation (CV) of the estimations regardless of extreme floods selected. For the LOCI scheme, TRMM and CMORPH estimations in certain floods show a significant improvement in the result but not for PERSIANN. PT scheme is found to be the best method as it improves most of the statistical performances as well as the rainfall distribution of the floods. In addition, this study also evaluates the sensitivity of the parameters used in the BC process where the result indicates that the PT scheme is found to be the least sensitive in correcting the daily SPP compared to the other two schemes. Finally, this study performs rainfallrunoff simulation by employing the Hydrological Modelling System (HEC-HMS) to validate the performance of the raw and bias-adjusted SPP for the 2014-2015 flood events in the Langat river basin. Generally, corrected precipitations exhibit a significant improvement during the high rainfall event especially LOCI-adjusted TRMM and CMORPH. For PERSIANN-simulated flow, the BC schemes are able to improve the discharge simulation. However, further calibration is suggested in order to enhance its accuracy