110 research outputs found

    Impact of unbalanced harmonic loads towards winding temperature rise using FEM modeling

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    This paper investigates the hot spot temperature of transformer thermal model due to unbalanced harmonic loads from the network. The finite element method has been used to solve the coupling multiphysic for heat transfer in solid and fluid. All material properties in the model were been took into consideration such as copper as the coil material, iron as the core material and transformer oil as the coolant material for the transformer. The transient study on the model has been set for 1minutes using 30 degree celcius as the ambient temperature reference. The simulation hot spot temperature result has been compared for rated load (without harmonic) versus the unbalanced load (with harmonic) which shown in 2D regime. It can be clearly seen the significant increment of the hotspot temperature of the transformer from the rated load to the unbalanced harmonic load. The result has successfully shows the detection of the prospect failure of the transformer due to the harmonic current load in a form of winding loss that contributes to the hotspot temperature of the transformer

    Visual Thinking Process and Emotions Through Expressive Art

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    Background: Drawing has a therapeutic function in the lives of people with special needs.These people need additional support for communication and learning.Researchers believed that drawing is an effective way for these people to show their self-esteem, emotions, social competence, and other hidden personalities. Art therapy teaches knowledge of visual art (drawing and painting). It is also known as expressive art because it assists in dealing with some emotions that are difficult for verbal communication. Furthermore, art therapy is beneficial for fine motor skill development. The aim of this study was to explore the use of expressive art in a group of autistic people. Subjects and Method: This was a qualitative study. A series of art therapy workshop were conducted in University of Malaya in collaboration with Malaysian Rehabilitation Council, and Maybank Foundation. A number of 18 people aged 8-17 years old with autism from Malaysian Rehabilitation Council were invited to University of Malaya for the art therapy workshop. They consisted of Malays, Chinese, and Indians. These peoplehad some level of communication problems. Art therapy workshop was conducted twice a month for 6 month with each session lasted for 4 hours. Art template, art materials, and a list of activities were given to each participant. Before the session, the participants informed the researchers verbally the scope of art that they would be drawing. The researchers observed the thinking process and emotions of the participants through the art activities. Results: Some of the art work was not related to what they have mentioned earlier. We found that art demonstrated their thought process. Drawing was more accurate in visualizing their thinking process rather than verbal communication. Besides, we detected a range of emotions illustrated from their final art work. Some of the emotions were psychological distress, happiness, and sadness. Conclusion: Expressive artis useful for visualizing thinking process of autistic people. Keywords: art therapy, autistic, visual thinking, emotions, expressive ar

    Analysis of AC-DC Converter Circuit Performance With Difference Piezoelectric Transducer Array Connection

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    This research presents a simulation analysis for the AC-DC converter circuit with a different configurations of the array connection of the piezoelectric sensor. The selection of AC-DC converter circuits is full wave bridge rectifier (FWBR), parallel SSHI (P-SSHI) and parallel voltage multiplier (PVM) with array configuration variation in series (S), parallel (P), series-parallel (SP) and parallel-series (PS). The system optimizes with different load configurations ranging from 10 kΩ to 1 MΩ. The best configuration of AC-DC converter with an appropriate array piezoelectric connection producing the optimum output of harvested power is presented. According to the simulation results, the harvested power produced by using P-SSHI converter connected with 3 parallel piezoelectric transducer array was 85.9% higher than for PVM and 15.88% higher than FWBR

    ART THERAPY FOR PEOPLE WITH AUTISM

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    Background: Art therapy is a technique used in mental health profession in which patients with special needs use creative process facilitated by the art therapist to explore patients‘ interpersonal and art skills. Art therapy teaches knowledge of visual art (drawing and painting) and the creative process involved is not only beneficial for fine motor skills development but also assists in dealing with emotions. The objectives were to identify interpersonal skills, to develop art skills and to increase self-esteem through art therapy activities. Subjects and Method: This was a qualitative study. A series of art therapy workshop were conducted in University of Malaya in collaboration with Malaysian Rehabilitation Council, Maybank Foundation, and University of Malaya. A number of 38 participants from Malaysian Rehabilitation Council who were autistic were invited to University of Malaya for the art therapy workshop. Their age range was from 8 – 17 years old and consisted of Malays, Chinese and Indians. It was a participant observer study in which the researcher studied the life of a group by sharing in its activities. Art therapy workshop was conducted for 6 months duration twice a month and each session was for 4 hours. Art template, art materials and a list of activities were given to each participant. Throughout the sessions, the way participants communicate and interact with researcher were documented to identify interpersonal skills. The development of art skills was through the teaching of art using the different art template for each session. Results: From the outcome of the artwork, participants showed increased self-esteem as their art skills improved throughout the art sessions. Conclusion: Art therapy is able to develop interpersonal skills, art skills and increase self-esteem of people with autism. Keywords: Art therapy, autism, interpersonal skills, art skills, self-estee

    Analysis of Formant Frequencies of the Correct Pronunciation of Quranic Alphabets Between Kids and Adults

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    It is an obligation for a Muslim to become skilled and proficient in reciting Al-Quran considering that Al-Quran is the fundamental source of revelation from Allah SWT. In Al-Quran, there are 28 alphabets where each of them has their own unique sound. The Quranic alphabets produce sound that are characterized from their point of articulation (Makhraj) and their characteristics (Sifaat). Knowing the correct way of pronunciation through engineering perspective may help Muslim in learning Al-Quran, in the sense that the signal of the experts can be used in Quranic teaching and learning as a reference model. Since both adults and children possess different vocal tract, therefore there will be different outcomes of the pronunciation between both experts. The features identification of the pronunciation of both experts is needed to represent the actual and correct pronunciation that will be used as a reference for Quranic teaching and learning at later. In this paper, the focus was on the identification and analysis of the correct pronunciation of the Quranic alphabets on the data obtained from adults and children experts. The first and second formant frequencies (F1 and F2) were used as the features where they were used to represent the pronunciation of each alphabet for both adults and children category. The speech analysis software PRAAT was used to accomplish the pre-processing of the data using Spectral Subtraction technique and also used to measure the F1 and F2 values. Linear Discriminant Analysis (LDA) was used for classification of the signals and results shows that some of the alphabets can be identified uniquely using F1 and F2 features of the two categories

    Contribution of rice fields to bird diversity in Peninsular Malaysia

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    There is a lack of documentation on rice fields as an important habitat that harbour different bird diversity compared to natural habitats in Peninsular Malaysia. This study investigated the contribution of rice fields to bird diversity in Peninsular Malaysia. A total of 83 rice fields and 53 natural habitats throughout Peninsular Malaysia were included in this study. Birds were observed and counted using point-count and mist-netting methods. A total of 10,707 bird-sightings, with rice fields, recorded 129 species from 15 orders and 50 families from October 2013 to December 2014; whilst natural forests recorded a total of 438 species from 14 order and 59 families from February 1992 to January 2015. Diversity t-test showed a significant difference in the species richness between the two different habitats (t=11.009, p<0.05). The high values of Δ+and ʌ+ in many areas of rice fields were significantly influenced by the presence of waterbirds, albeit low species richness. This temporary wetland habitat harbours land birds and waterbirds in one place. The data presented here suggest that waterbirds and migratory birds in rice fields contribute significantly to the total bird species found in Peninsular Malaysia

    The effect of quick response manufacturing in supply chain activities: A case study of automotive company in Malaysia

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    The new era of industrial revolution 4.0, requires a lot of improvement especially in automotive assembly line. A poor flow on supply chain especially on logistic in the company affect the company performance. Insufficient planning may lead to less efficiency, quality and productivity loss. The objective of this study is to improve the critical supply chain in the automotive industry by studying the current data given by the company and used it to simulate on WITNESS. The output from the current simulation will determine on how to improve the supply chain by doing some changes in which lead to the optimized condition. After series of simulations, the output shows improvement especially on idle time and busy time. The idle time that possessed was under 20% while the busy time between 70% until 90% across the mechanical and trim sections

    Effectiveness of Antibiotic Prophylaxis for Leptospirosis among Adults: A Systematic Review

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    Leptospirosis is one of the most widespread re-emerging zoonoses in the world. Malaysia is known to be an endemic country for human leptospirosis, with a case fatality rate of 2.11%, and an average annual incidence rate of 7.80 cases per 100,000 individuals. This systematic review is conducted to determine the effectiveness of antibiotic prophylaxis for leptospirosis among the adult populations who are highly at risk of getting infected. A systematic search was performed for the relevant titles, abstracts and keywords on PubMed, Scopus, Cochrane and Google Scholar from inception to November 2017 based on the PICO strategy; which returned 126 studies. Screening of abstracts had shortlisted 19 studies and data extraction was conducted for 8 studies which had been accepted after review of the full text. For the evaluation of antibiotics prophylaxis effectiveness against leptospirosis, only trials and cohort studies with risk ratio (RR) were selected. The articles were analyzed from the viewpoint of the dosage, adverse effects, study settings and effectiveness of the antibiotic prophylaxis. Using fixed effects model, pooled RR showed protective association between antibiotic prophylaxis use against the incidence of leptospirosis (RR = 0.31; 95% CI: 0.20, 0.48). Antibiotic prophylaxis for leptospirosis had been shown to be effective in preventing the incidence of the disease among high-risk populations and carries minimal adverse effects. It is recommended that the practice of antibiotic prophylaxis for leptospirosis is included in the standard protocol for leptospirosis prevention among people at high-risk, including disaster response teams and patrons of eco-sports tourism activities; with the drug of choice being doxycycline, either as a single 200 mg dose or weekly dose of 200 mg for the duration of exposure, based on the setting, duration of event and resources available

    Current status of acute hepatopancreatic necrosis disease (AHPND) of farmed shrimp in Malaysia

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    A report about a disease problem in cultured whiteleg shrimp (Penaeus vannamei) was first received by the National Fish Health Research Center (NaFisH) in 2011 from Perak State showing signs of white feces and slow death leading to serious mortality rate. Later, in September of the same year, the Malaysian Shrimp Farmers Association (MSFA) reported to Department of Fisheries (DOF) severe mortalities in almost all of the whiteleg shrimp farms throughout Peninsular Malaysia. Sampling of shrimps for disease diagnosis was then conducted by NaFisH. The bacteriological and histopathological examinations revealed respectively the isolation of V. parahemolyticus and massive sloughing of hepatopancreatic epithelial cells. The disease was subsequently identified as acute hepatopancreatic necrosis disease (AHPND). From our 3-year study, the annual prevalence rates of AHPND were 50%, 26% and 73% in 2011, 2012 and 2013, respectively. At present, AHPND still persists in Malaysia but at a lower prevalence. The risk factors associated with the disease were studied, however, varied environmental and management data analyzed were inconclusive to relate any one parameter directly to the disease. To help ensure the early detection of AHPND, an experimental observation study on `gut scorecard was carried out and this was confirmed by PCR and histopathology. Validation of this technique has yet to be carried out to ensure its reliability. We also examined the potential use of some commercial products such as probiotics and disinfectants available in the market but unfortunately results showed that they were not effective in controlling AHPND. Control measures applied by the farmers such as the use of probiotics were also verified but data generated likewise appeared to be inconclusive. On the contrary, our preliminary study on the antibacterial property of the plant extracts, i.e. betel and lemongrass, incorporated in the feed showed some prophylactic and chemotherapeutic potential against AHPND. However, comprehensive in vitro and in vivo trials are still currently being undertaken to elucidate its efficacy and practical applications. To ensure the shrimp industry s sustainability in Malaysia, results of our ongoing and future studies aimed at preventing and controlling unwarranted outbreaks of AHPND and other emerging transboundary diseases of penaeid shrimps will be continually disseminated to shrimp farmers and pertinent stakeholders

    Passively Q-switched Erbium-doped fiber laser with brass-based saturable absorber

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    The operating wavelength in the 1.5 µm region is made accessible through an Erbium-doped fiber as a gain medium. The minimum optical loss of this region has proven beneficial in the application of pulsed fiber lasers. However, the ideal material to act as passive modulator for the system is yet to be found. Therefore, this research proposed the generation of pulsed fiber laser using metal based passive saturable absorber by utilizing brass-based 3D printer filament. A free-standing film was fabricated using chitin as host polymer for ease of integration in the laser ring cavity. The Erbium-doped fiber laser with brass-chitin based polymer composite film generated Q-switched pulses within the input pump power of 135.7 mW to 172.3 mW. The repetition rate was increased from 55.80 kHz to 68.03 kHz. Meanwhile the pulse width was reduced from 3.06 µs to 2.24 µs, with corresponding maximum instantaneous pulse energy and peak power of 2.10 nJ and 882.71 µW, respectively. The signal-to-noise ratio was measured at 67 dB, indicating a highly stable pulse generation
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