Classification of Malaysian vowels using formant based features

Automatic speech recognition (ASR) has made great strides with the development of digital signal processing hardware and software, especially using English as the language of choice. Despite of all these advances, machines cannot match the performance of their human counterparts in terms of accuracy and speed, especially in case of speaker independent speech recognition. In this paper, a new feature based on formant is presented and evaluated on Malaysian spoken vowels. These features were classified and used to identify vowels recorded from 80 Malaysian speakers. A back propagation neural network (BPNN) model was developed to classify the vowels. Six formant features were evaluated, which were the first three formant frequencies and the distances between each of them. Results, showed that overall vowel classification rate of these three formant combinations are comparatively the same but differs in terms of individual vowel classification

Evaluation of external radiological hazard in bottom and fly ash from coal fired pilot plant

Coal is the most important fossil fuel for non-nuclear power generation industries. The burning of coal generates ashes which contain natural radionuclides namely 238U and 232Th series including 40K that are released into the environment. This study presents an evaluation of the radioactivity content found in the feed coal and ashes sampled from typical coal fired power plants. The sample was measured for activity concentration of the radionuclides and the results were used to evaluate the radiological hazard index of the sample.The findings revealed that the values of the external radiological hazard obtained were acceptable and safe to be reutilized

Building and Managing Social Capital in Virtual Communities

We suggest that the development and sustainability of social capital is related to the social context in which individuals, groups or firms operate. Therefore, we argue that there is a direct relationship between how one party conceives to be benefited from being part of another group or network and its implication for the development of social capital. In this paper, we use a social exchange metaphor for understanding the challenges related to the management of social capital in a virtual community. First, we provide an overview of virtual community and discuss the application of Information and Communication Technology (ICT) for supporting this type of community. Second, we address the management challenges for the development process of social capital from a sociological standpoint. Lastly, we suggest the implications of study for the management of social capital in virtual community. The following research questions guide this study—What is/are the key strategic challenges for the management of social capital in virtual community? How do establish an effective knowledge sharing process for supporting the development of social capital in a virtual community? How can the social exchange metaphor help in managing the strategic challenges related to the formation of social capital in a virtual community

Detection Of Defects On Weld Bead Through The Wavelet Analysis Of The Acquired Arc Sound Signal

Recently, the development of online quality monitoring system based on the arc sound signal has become one of the main interests due its ability to provide the non-contact measurement. Notwithstanding, numerous unrelated-to-defect sources which influence the sound generation are one of the aspects that increase the difficulties of applying this method to detect the defect during welding process. This work aims to reveal the hidden information that associates with the existence of irregularities and porosity on the weld bead from the acquired arc sound by applying the discrete wavelet transform. To achieve the aim, the arc sound signal was captured during the metal inert gas (MIG) welding process of three API 5L X70 steel specimens. Prior to the signal acquisition process, the frequency range was set from 20 Hz to 10 000 Hz which is in audible range. In the next stage, a discrete wavelet transform was applied to the acquired sound in order to reveal the hidden information associated with the occurrence of discontinuity and porosity. According to the results, it was clear that the acquired arc sound was not giving an obvious indication of the presence of defect as well as its location due to the high noise level. More interesting findings have been obtained when the discrete wavelet transform (DWT) analysis was applied. The analysis results indicate that the level 8 of the approximate and detail wavelet coefficient have given a significant sign associated with the presence of irregularities and porosity respectively. Moreover, despite giving the information on the surfaces pores, the detail wavelet coefficient was found to give a clear indication of the sub-surface porosity formation during welding process. Hence, it could be concluded that the hidden information with respect to the occurrence of discontinuity and porosity on the weld bead could be obtained by applying the discrete wavelet transfor

Pembelajaran terarah kendiri melalui pendekatan pembelajaran berasaskan masalah: pola kajian berkenaan beberapa artikel terpilih

Pembelajaran terarah kendiri merupakan antara elemen penting dalam implementasi pendekatan pembelajaran berasaskan masalah. Sehubungan itu, sebanyak tujuh artikel dipilih berdasarkan beberapa kriteria tertentu melalui pengkalan data ISI Web Of Science. Artikel-artikel tersebut dianalisis dalam menjawab tiga persoalan kajian iaitu (i) Apakah pemilihan sampel bagi kesemua kajian? (ii) Apakah pemilihan reka bentuk kajian yang digunakan dalam kesemua kajian?(iii) Apakah persamaan dan perbezaan intipati dan dapatan bagi kesemua kajian?Melalui analisis yang dijalankan didapati sebahagian besar kajian menggunakan reka bentuk kajian kes dan reka bentuk kajian eksperimen. Selain itu, pemilihan sampel bagi kebanyakan kajian tertumpu kepada pelajar jurusan perubatan serta fokus atau isu yang diketengahkan adalah dalam melihat faktor dan kesan implementasi pendekatan pembelajaran berasaskan masalah terhadap pembelajaran terarah kendiri

Acoustic Analysis of Nigerian English Vowels Based on Accents

Accent has been widely acclaimed to be a major source of automatic speech recognition (ASR) performance degradation. Most ASR applications were developed with native English speaker speech samples not minding the fact that the majority of its potential users speaks English as a second language with a marked accent. Nigeria like most nations colonized by Britain, speaks English as official language despite being a multi-ethnic nation. This work explores the acoustic features of energy, fundamental frequency and the first three formats of the three major ethnic groups of Nigerian based on features extracted from five pure vowels of English obtained from subjects who are Nigerians. This research aimed at determining the differences or otherwise between the pronunciations of the three major ethnic nationalities in Nigeria to aid the development of ASR that is robust to NE accent. The results show that there exist significant differences between the mean values of the pure English vowels based on the pronunciation of the three major ethnics: Hausa, Ibo, and Yoruba. The differences can be explored to enhance the performance of ASR in recognition of NE

Blended problem based learning (BPBL): opportunities and challenges to be implemented in Malaysian context

One of the key objectives in the National Education Blueprint is to produce students with higher order thinking skills. The concern is raised based on the poor performances of Malaysian students in the international assessments of Trends in Mathematics and Science Study (TIMSS) and Programme for International Student Assessment (PISA). One of the factors that might contribute to the decline in achievement is the teaching approach applied in Malaysian schools. A revolution in current teaching approach is thus needed. Problem based learning (PBL) is one of the teaching approach being widely implemented and is proven to be beneficial in stimulating students? higher order thinking skills through solving real-world problems. Similarly, the integration of technology during teaching and learning process such as online learning has also been proven to improve students? higher order thinking skill. Based on these foundations, the blended problem based learning (BPBL) that integrates face-to-face PBL and online learning platforms, is believed seems to be an effective teaching approach that can improve PBL and thus enhancing students? higher order thinking skill. This is due to BPBL offers the benefit of both face-to-face PBL and online learning. However, the studies in this area are still insufficient particularly in Malaysian schools? context. Thus, this paper is aimed at discussing on the opportunities and challenges faced in the implementation of BPBL in Malaysian context

IMPORTANCE OF THE D2 RECEPTOR FOR ONE- AND MULTI-TRIAL PSYCHOSTIMULANT-INDUCED BEHAVIORAL SENSITIZATION IN PREWEANLING RATS

The neural mechanisms mediating one-trial and multi-trial behavioral sensitization during early ontogeny are poorly understood. The purpose of this thesis was to assess the importance of D2-like receptors for the induction of cocaine- and methamphetamine-induced one-trial and multi-trial behavioral sensitization during the middle and late preweanling period. In a series of four experiments, rats were injected with saline or the selective dopamine D2-like receptor antagonist raclopride 15 min prior to treatment with the indirect dopamine agonists cocaine or methamphetamine. Acute control groups received two injections of saline. The pretreatment regimens occurred on either PND 16 or PND 20 (one-trial behavioral sensitization) or PND 13-16 or PND 17-20 (multi-trial behavioral sensitization). On PND 17 or PND 21, rats were challenged with either cocaine or methamphetamine and sensitized responding was assessed. With only a single exception, both one -trial and multi-trial cocaine- and methamphetamine-induced sensitization was evident on PND 17 and PND 21. Importantly, the D2-like receptor antagonist raclopride did not prevent the induction of cocaine- or methamphetamine-induced one-trial behavioral sensitization. In regards to multi-trial behavioral sensitization, raclopride failed to inhibit cocaine -induced sensitized responding on PND 17 and PND 21. Interestingly, higher doses of raclopride (0.5 and 1 mg/kg) were able to prevent the induction of multi-trial methamphetamine-induced sensitization on PND 17. Therefore, D2-like receptor antagonism differentially affected methamphetamine -induced behavioral sensitization depending on whether a one-trial or multi-trial paradigm was employed. When considered together, these results suggest that the neural mechanisms underlying the methamphetamine -induced behavioral sensitization of preweanling rats differs depending on the type of experimental paradigm (one- vs multi-trial) being used. Other potential explanations (i.e., nonspecific antagonist effects, impact of contextual conditioning, etc.) for this interesting effect are presented in the Discussion

Chemical Components from the Light Petroleum Soluble Fraction of Uvaria cordata (Dunal) Alston

Chromatographic separation of the light petroleum extract from the stem bark of Uvaria cordata (Dunal) Alston led to the isolation of the triterpenoids glutinol and taraxerol in addition to the cyclohexene derivatives, pipoxide and its chlorohydrin. A small amount of benzyl benzoate was also isolated