bluuebunny/crossref_metadata_2025 huggingface dataset:
Metastatic uveal schwannoma of blue‐eyed dogs
Authors: Duke Felicia D. , Brudenall Denise K. , Scott Erin M. , Teixeira Leandro B. C. , Dubielzig Richard R.
Published: January 2013

A formalin‐fixed left, blue eye, from a 9‐year‐old, spayed female beagle dog was submitted to theComparativeOcularPathologyLaboratory ofWisconsin (COPLOW) for light microscopic evaluation. The history included glaucoma and an abnormal appearance for 6 months and then the development of a uveal mass. The histologic diagnosis was a spindle cell tumor of blue‐eyed dogs (SCTBED). InJune of 2012, the dog was euthanized due to ailing health, and there was radiographic andpostmortemexamination evidence of neoplastic metastasis. This is the first reported case of this primary ocular neoplasm metastasizing, and we propose to renameSCTBEDas a uveal schwannoma of blue‐eyed dogs.
Kajian Sifat Kehausan Dan Kekerasan Komposit Matriks Aluminium
Authors: Idris Jamaliah , Salim Farid , Suliman Zahrulail , Osman Edynoor
Published: January 2013

Dewasa ini, bahan komposit matriks logam digunakan dengan meluas di dalam sektor perindustrian terutamanya industri automotif dan pengangkutan udara. Kajian ini menekankan kepada penghasilan komposit aluminium yang ditetulangi dengan 20% dan 40% partikel SiC melalui kaedah penekanan sejuk proses metalurgi serbuk. Pensinteran pada suhu 450Â°C dan 550Â°C dilakukan bagi meningkatkan sifat-sifat mekanikal spesimen yang telah dihasilkan. Objektif kajian adalah merangkumi kepada pengujian ke atas sifat kekerasan dan sifat haus spesimen yang dihasilkan. Ujian kekerasan Vickers menunjukkan Al tulen/SiC/40p yang disinter pada suhu 550Â°C menunjukkan nilai kekerasan yang maksimum iaitu 90.3Hv. Sementara itu, ujian haus â€˜pinâ€“on discâ€™ juga menunjukkan bahawa Al tulen/SiC/40p memberikan sifat rintangan haus yang terbaik. Ini menunjukkan rintangan haus bertambah apabila nilai kekerasan semakin tinggi.

Kata kunci: Teknik metalurgi serbuk; pensinteran; komposit matriks aluminium; ujian kekerasan Vickers; ujian haus pin on disc

Nowadays, metal matrix composites have been widely used in the industrial sectors especially in the automotive and aerospace applications. The present work is focused on the production of Aluminium matrix composite reinforced with silicon carbide particles (SiCp) of varying weight fraction 20% and 40% using a cold compaction powder metallurgy. The sintering of the composites was carried out at 450Â°C and 550Â°C to increase the mechanical properties of the composites. The objective of this study is to investigate the relationship between hardness properties and wear properties of the specimens. A Vickers hardness test and a pin-on-disc wear test showed that the Al pure/SiC/40p composite treated at 550Â°C exhibited the maximum hardness value, value of 90.3 Hv and the most excellent wear resistance properties. This result showed that the wear resistance increased when the hardness value increased.

Key words: Powder metallurgy technique; sintering; Aluminium matrix composite; Vickers hardness; pin on disc wear test
Sebatian Metoksiaromatik Sebagai Substrat Pertumbuhan dan Pengaruh Enzim Demetilase dalam Acetobacterium Woodii DSM 1030
Authors: Hj. Kalil Mohd. Sahaid , Zaki Muhammad , Wan Yusoff Wan Mohtar , Mohd. Salleh Mohammad Ramlan
Published: January 2013

Penyelidikan ini bertujuan untuk menyaring substrat organik bagi untuk penghasilan sel–sel A. woodii teraruh demetilase. Pertumbuhan A. woodii dilakukan dalam medium “Balch” yang mengandungi sumber karbon berbeza dalam keadaan anaerobik. Sebanyak sebelas substrat telah diuji iaitu anisol, 2– dan 3–metoksifenol, asid vanilik, asid siringik, asid 2,3,4–, 2,4,5– dan 3,4,5–trimetoksi benzoik, 2,3,4–, 2,4,5– dan 3,4,5–trimetoksi benzil alkohol. 2–metoksifenol merupakan substrat terbaik untuk pertumbuhan A. woodii pada kadar pertumbuhan spesifik 0.14 j–1. Penghasilan sel–sel teraruh demetilase dilakukan dalam kultur kemostat pada kadar pencairan (D) 0.0j–1. Sel-sel pada keadaan mantap dituai dalam keadaan anaerobik dan dipekatkan sebelum digunakan. Pertumbuhan A. woodii didapati maksimum dengan menggunakan kepekatan 0.62 g/L 2–metoksifenol sebagai sumber karbon tunggal. Tindak balas penyahmetilan oleh sel–sel A. woodii meningkat sebanyak 78% apabila 2–metoksifenol sebanyak 0.31 g/L ditambah dalam medium yang mengandungi fruktosa (1% w/v) semasa kultur kemostat.

Kata kunci: tindak balas penyahmetilan; demetilase; sel-sel tertuai; metosiaromatik, Acetobacteriumwoodii

The objective of this project was to screen organic substrate suitable for the growth of A. woodii, and as for the production of demethylase. A. woodii was grown in “Balch” medium containing different carbon sources. Eleven substrates were tested including anisole, 2– and 3–methoxyphenol, vanilic acid, syringic acid, 2,3,4–, 2,4,5– and 3,4,5–trimethoxy benzoic acid and 2,3,4–, 2,4,5– and 3,4,5–trimethoxy benzyl alcohol. It was found that 2–methoxyphenol was the best substrate with a specific growth rate of 0.14 h–1. The production of demethylase induced cells was carried out in a chemostat culture at a dilution rate (D) of 0.08 h–1. Cells were harvested at steady state of growth and concentrated before use. Optimal concentration of 2–methoxvphenol as the sole carbon source was 0.62 g/L. Demethylation reaction of 0.31 g/L 2–methoxyphenol by induced culture increases 78% relative to the chemostat culture containing only fructose.

Key words: Demethylation reaction; demethylase; harvested cells; methoxyaromatic; Acetobacteriumwoodii
Computer–Based Monitoring System for Analysing Surface Leakage Current in an IEC 587 Test Set–Up
Authors: Md. Piah Md. Afendi , Darus Ahmad
Published: January 2013

Surface discharge is a common electrical discharge that normally occurs on outdoor insulators under wet and contaminated conditions. The dry–band discharge exists because of the leakage current that flows on the insulator surface. Measuring the surface leakage current can identify the performance of insulating materials as well as the characteristics of discharges. A computer–based on–line monitoring of surface leakage current is found to be more practical due to the long period of time taken in conducting the laboratory test. This paper describes the design and development of a leakage current monitoring system associated with surface tracking and erosion resistance test set–up of IEC 587. The LabVIEW software package is used to develop a measurement program for recording and analysing leakage current signals. Experimental works have shown the capability of the developed system in detecting the performance of insulating materials as well as identifying the characteristics of the surface discharges. Besides the on–line monitoring function, a data storage feature is also added to the system to allow for further analysis.

Key words: surface discharge; leakage current; signal analysis; virtual instrument program
An Authentication Method for Secure Internet Transaction Using Smart Card and Secure Coprocessor
Authors: A. Ayad Mustafa , Prakash V. , Noordin N. K. , Wan Adnan W. A.
Published: January 2013

Sekian lama pengguna telah meletakkan kepercayaan secara menyeluruh dalam menunjukkan pengenalan diri secara fizikal. Walau bagaimanapun, dengan terciptanya Kad Pintar, ia telah memberi sejenis kepercayaan yang sama di dalam dunia keselamatan. Kad Pintar mengandungi tandatangan digital, kekunci, lesen dan sijil–sijil persendirian, yang mana telah berjaya meningkatkan kepercayaan di kalangan pengguna dengan kesahihan maklumat serta ciri–ciri keselamatan yang tinggi. Selain itu, Kad Pintar menjadi lebih menarik dengan keupayaan untuk mewujudkan sistem komunikasi yang lebih selamat di dalam sistem komputer yang telah sedia ada. Dalam kertas kerja ini, kami memperkenalkan beberapa kaedah baru di dalam sistem yang menggunakan Kad Pintar dan pemproses–bersama untuk memastikan keselamatan di dalam transaksi internet serta menyediakan penyelesaian untuk menghalang kebarangkalian jika berlaku sebarang masalah di dalam sesebuah sistem.

Kata kunci: Kad pintar; pengesahan diri; keselamatan; imternet; pemproses bersama

Consumers for years have put their trust in physical means of proving personal identity. However, with the advent of Smart Cards, creating the same sense of trust in the security world is a challenge. Smart Cards, carrying digital signatures, private keys and certificates, offer an approach to trust in the security world that integrates the familiar card form with the capability to provide strong authentication. The same characteristics that make Smart Cards attractive change the threat environment to secure communications in traditional computer systems. In this paper, we propose new methods of authentication in systems that use Smart Cards and secure coprocessor to ensure secure Internet transactions and provide solutions on how to defend against some of the possible attacks.

Key words: Smart card; authentication; security; internet; coprocessor
Aplikasi Model Kolb Dalam Program Keusahawanan Remaja
Authors: Hj. Othman Norasmah , Lope Pihie Zaidatol Akmaliah , Nazri Mohd. Ibrahim , Ahmad Tarmizi Rohani
Published: January 2013

Pemilihan kaedah pengajaran yang bersesuaian penting kerana ia berupaya membantu meningkatkan tahap pemahaman pelajar terhadap sesuatu perkara. Sumber dan literatur berkaitan pengajaran menyokong penuh program keusahawanan di sekolah menggunakan kaedah pengajaran berpusatkan pelajar. Namun, bukti-bukti nyata untuk menyokong atau menyangkal kenyataan ini masih kurang. Kajian ini merupakan satu kajian tinjauan terhadap gaya pengajaran yang digunakan penceramah Program Keusahawanan Remaja dengan berasaskan kepada Model Kolb. Tujuan kajian ialah untuk meninjau sama ada terdapat atau tidak percanggahan antara kaedah pengajaran yang kerap digunakan dengan yang sesuai digunakan mengikut persepsi pelajar. Kajian ini melibatkan 425 pelajar program Keusahawanan Remaja. Soal selidik telah digunakan sebagai instrumen. Dapatan kajian menunjukkan terdapat percanggahan antara kekerapan penggunaan kaedah pengajaran oleh penceramah dengan kesesuaian kaedah pengajaran mengikut persepsi pelajar. Secara khususnya, kaedah pengajaran berpusatkan kepada guru di mana pelajar bertindak sebagai pemerhati masih banyak digunakan dalam proses pengajaran dan pembelajaran berbanding kaedah berpusatkan pelajar mengikut persepsi pelajar.

Kata kunci: kaedah pengajaran berpusatkan pelajar; program keusahawanan remaja; model Kolb

It is important to select appropriate teaching methods because it enhances students understanding of the subject. Teaching resources and related literature support the use of student–centered method in entrepreneurship programmes. Nevertheless, there is little evidence to support or refute this. This study of students´ perception indicated there were discrepancies between methods actually used and those perceived as suitable based on Kolb´s Model. This preliminary study involved 425 students from the Entrepreneurship Training Programme. The instrument employed was a set of questionnaires. Findings indicate that there was a slight discrepancy between the methods frequently used by the facilitators and the methods perceived as suitable for the students. More specifically, teacher–centered method is still widely used in entrepreneurship programmes compared to students–centered methods.

Key words: student centered teaching methods; enterpreneurship programmes; Kolb's model of teaching
Amalan Etika Profesion Perguruan Di Kalangan Guru–guru Sekolah Kebangsaan Kampung Melayu, Kulai, Johor. Satu Tinjauan
Authors: Buntat Yahya , Masrom Zainuddin
Published: January 2013

Kajian berbentuk tinjauan ini dilakukan untuk melihat amalan etika profesion perguruan di kalangan 48 orang responden guru–guru Sekolah Kebangsaan Kampung Melayu, Kulai, Johor. Aspek–aspek etika profesion perguruan yang dilihat dalam kajian ini adalah perkara–perkara yang berkaitan dengan tanggungjawab guru terhadap pelajar, tanggungjawab guru terhadap masyarakat dan negara, tanggungjawab guru terhadap rakan sejawat dan profesion dan tanggungjawab guru terhadap ibu bapa. Maklumat kajian diperolehi melalui soal selidik yang diedarkan kepada responden dan dianalisis dalam bentuk kekerapan dan peratusan. Hasil kajian mendapati guru–guru sekolah ini keseluruhannya telah mengamalkan etika profesion perguruan dalam aspek yang dikaji. Berdasarkan dapatan kajian ini beberapa cadangan dikemukakan untuk meningkatkan lagi tahap amalan etika profesion perguruan di kalangan guru–guru secara amnya.

Kata kunci: etika profesion perguruan; martabat profesion
Process Parameters Dependence Of Acrylonitrile Butadiene Styrene (ABS) Flow Patterns Inside A Capillary Rheometer Barrel
Authors: M. Ariff Zulkifli , A. Bakar Azhar , Z. Arif M. Nasir
Published: January 2013

Corak aliran leburan ABS di dalam barel rheometer kapilari tegasan-malar telah dikaji. Kesan perubahan parameter pemprosesan seperti suhu, tekanan dan sesaran penolak terhadap corak aliran diselidik. Suhu and sesaran penolak didapati mempunyai pengaruh yang ketara ke atas corak aliran. Ini diperhatikan melalui perubahan terhadap ketebalan lapisan berwarna dan kemunculan bentuk aliran yang kompleks. Tiada perubahan corak aliran yang besar dipamerkan apabila tekanan pengekstrudan ditingkatkan melebihi had tekanan bagi berlakunya rekahan leburan. Profil halaju diukur daripada corak aliran menggunakan penganalisis imej dan keputusan ujian menunjukkan bahawa terdapat sedikit penyimpangan antara profil halaju yang diukur melalui ujikaji dengan profil yang di perolehi secara pengiraan teori menggunakan persamaan aliran bendalir tak-Newtonan yang telah terbukti keberkesanan penggunaannya. Sisihan tersebut berkurangan sekiranya suhu pengekstrudan ditingkatkan namun menjadi agak rumit secara relatifnya apabila sesaran penolak yang lebih besar digunakan.

Flow patterns of ABS melt inside a constant-stress capillary rheometer barrel was investigated. The effects of variations in process parameters such as temperature, pressure and plunger displacement towards the flow patterns were studied. Temperature and plunger displacements were found to have prominent influences on the flow patterns where changes in pigmented layer thickness and complex flow were observed respectively. No significant effect was displayed on the flow patterns when extrusion pressure was increased exceeding pressure limit of melt fracture occurrence. Velocity profiles were measured from the flow patterns using an image analyser and it was discovered that some deviations existed between experimental measured velocity profiles and that of theoretically calculated valves using an established non-Newtonian fluid flow equation. These deviations reduced with extrusion temperature but become relatively complicated when large plunger displacement was applied.
Curing Characteristics of Unsaturated Polyester/aramid Reinforced Composite: Microwave vs. Thermal Energy
Authors: Rahmat A. R. , Day R. J.
Published: January 2013

Proses permatangan yang biasa digunakan untuk menghasilkan komposit termoset ialah dengan kaedah terma. Terdapat banyak kelemahan untuk kaedah ini, termasuklah kitaran masa permatangan yang panjang. Kertaskerja ini melaporkan alternatif lain bagi proses permatangan komposit poliester tak tepu/aramid iaitu dengan menggunakan tenaga gelombang mikro. Perbezaan ciri permatangan bagi komposit yang dihasilkan melalui kaedah oven gelombang mikro dan oven lazim telah dibandingkan. Analisis kalorimetri pengimbas pembezaan (DSC) menunjukkan bahwa permatangan komposit dengan kaedah gelombang mikro adalah lebih cepat berbanding dengan kaedah terma. Analisis Spektroskopi inframerah transformasi Fourier (FTIR) pula menunjukkan keberkesanan alat ini membandingkan pertukaran poliester C=C dan stirena C=C yang menjalani permatangan gelombang mikro dan terma.

Kata kunci: Permatangan gelombang mikro; komposit poliester tak tepu/aramid; Resin pengacuan pindah (RTM); Kalorimetri pengimbas pembezaan (DSC); Spektroskopi inframerah tranformasi Fourier (FTIR)

Conventional curing processes for producing thermoset composites use a thermal approach, which suffers from numerous disadvantages, including a long curing cycle time. This paper reports on an alternative curing process of an unsaturated polyester/aramid composite using microwave energy. The differences in curing characteristic of the composites fabricated between microwave and conventional ovens method were compared. Differential Scanning Calorimeter (DSC) analysis showed that microwave curing of composite was much faster than thermal curing while Fourier Transform Infrared Spectroscopy (FTIR) analysis was found to be very much significant in comparing the conversion of polyester C=C and styrene C=C undergoing microwave and thermal curing.

Key words: Microwave curing, unsaturated polyester/aramid composite; Resin Transfer Moulding (RTM); Differential scanning calorimetry (DSC); Fourier transform infrared spectroscopy (FTIR)
Hydrological Analysis of a Drained Peat Basin Using Time Series Correlation and Crossâ€“correlation Functions
Authors: Katimon Ayob , Abd. Wahab Ahmad Khairi
Published: January 2013

Satu pendekatan algebra mudah korelasi dan korelasi silang telah digunakan untuk mengkaji hidrograf aliran sungai di lembangan tanah gambut. Analisis melibatkan pemindahan pemboleh ubah input (hujan) and pemboleh ubah output (aliran sungai atau paras air tanah). Analogi kepada sistem signal input-output dalam bidang elektronik, akuifer tanah gambut dianggap sebagai suatu sistem penapis. Sistem penapis tersebut mampu untuk memindah, menahan atau menghapus pemboleh ubah input (signal input) sebelum pemboleh ubah output dihasilkan. Sifat aliran yang melalui sistem akuifer boleh diterjemahkan daripada darjah pindahan signal input. Beberapa parameter akuifer penting telah dikenal pasti, iaitu tempoh masa gerak balas, perbezaan antara jenis aliran (aliran cepat, sederhana atau aliran dasar) dan masa tunda. Kesemua parameter hidrologi tersebut diperlukan sebagai parameter reka bentuk bagi suatu projek sumber air dalam kawasan yang dilitupi oleh akuifer bertanah gambut.

Kata kunci: Hidrologi gambut; fungsi; korelasi silang; fungsi korelasi spektra; lembangan kompleks

A simple algebraic correlation and crossâ€“spectral approach was applied to study the stream flow hydrograph of peat basin. The analysis involved the transformations of input variables (rainfall) and output variables (stream flow and water table). Analogous to the inputâ€“output signal in electronics, the peat aquifer is considered as a filtering system. The filter is able to transform, retain or eliminate the input variables (input signal) before the output variables (output signal) are created. The behaviour of flow through basin aquifer system is deduced from the degree of the transformation of the input signal. Several important aquifer parameters were deduced from the transformation process. They are the response time, the distinction between flows (quickâ€“flows, intermediate flow or baseâ€“flow) and the delay. These hydrological parameters are required as design parameters for a water resource project within a basinâ€“underlain peat soil aquifer.

Key words: Peat hydrology; cross correlation function; spectral correlation function complex basin
Rangkaian Neural dalam Peramalan Harga Minyak Kelapa Sawit
Authors: Ismail Zuhaimy , Khamis Azme , Ali Rosmah
Published: January 2013

Kertas kerja ini membincangkan penggunaan rangkaian neural suap-kehadapan dengan satu aras tersembunyi digabungkan dengan algoritma rambatan balik dan didapati ia sesuai untuk memerihalkan data harga minyak sawit. Kajian awal yang telah dilakukan oleh Azme et al. mendapati analisis regresi berganda kurang sesuai digunakan kerana masalah multikolineariti dalam data kajian. Lima harga minyak sayuran dunia iaitu minyak sawit mentah, minyak isirong, minyak kacang soya, minyak kelapa dan minyak biji sawi telah dianalisis. Dua model telah dicadangkan iaitu, NN1 dan NN2. Hasil kajian mendapati bahawa kedua-dua model telah menunjukkan prestasi yang tinggi dengan mencatatkan nilai pekali penentuan, R2 yang tinggi iaitu 0.938 dan 0.940 masing-masing. Umumnya, rangkaian neural berupaya menjadi satu kaedah alternatif sekiranya masalah multikolineariti wujud terhadap data yang dikaji.

Kata kunci: Harga minyak sawit, multikolineariti, rangkaian neural suap-kehadapan, fungsi penggiat, algoritma rambatan balik

The application of feed forward neural network with one hidden layer, which is combined with back propagation algorithm, has been discussed in this paper. This study found that the combination of these two methods was reliable to explain the palm oil price data. A research was done earlier by Azme et al. and found that multicollinearity problem occurred in data analysis when multiple linear regression was applied. We considered five vegetable oil prices namely, crude palm oil, soybean oil, palm kernel oil, coconut oil and rapeseed oil in this study. Two models have been proposed, i.e. NN1 and NN2 and these models performed very well with the determination coefficient R2, were 0.938 and 0.940 respectively. Generally, neural network is able to be an alternative method if multicollinearity problem occurred in the surveyed data.

Key words: Palm oil juice, multicollinearity, feed forward neural network, activation function, back propagation algorithm
Integration of Projection Histograms and Linear Prediction for Object Tracking
Authors: Yeoh Phaik Yong , Abu Bakar Syed Abdul Rahman
Published: January 2013

Kertas kerja ini mengemukakan satu sistem visual untuk menjejak objek bergerak yang dapat beroperasi secara masa–nyata, efisien dan tahan lasak, dengan menggunakan turutan imej yang diperolehi daripada satu kamera statik. Algoritma menjejak yang dikemukakan menggabungkan teknik Unjuran Histogram dan kaedah Ramalan Linar untuk mencapai kelajuan menjejak yang lebih tinggi. Unjuran Histogram dilakukan untuk mendapatkan lokasi sebenar bagi objek yang dijejak, manakala kaedah Ramalan Linar disertakan dalam algoritma menjejak yang dikemukakan untuk meramal lokasi bagi objek bergerak dalam imej seterusnya, berdasarkan beberapa ukuran centroid sebelumnya. Hasil gabungan teknik Unjuran Histogram dan tertib kedua Ramalan Linar telah membolehkan algoritma yang dikemukakan untuk menjejak objek bergerak dengan tepat. Potensi and kecekapan bagi algoritma menjejak yang dikemukakan telah dibuktikan oleh keputusan menjejak yang baik pada beberapa turutan imej eksperimen.

Kata kunci: menjejak pergerakan, Unjuran Histogram, Ramalan Linar, perbezaan bingkai

In this paper, a real–time, efficient and robust visual tracking system for a single moving object using image sequences captured by a stationary camera is presented. The proposed tracking algorithm integrates the Projection Histograms technique with the Linear Prediction method in order to achieve a faster tracking speed. The Projection Histograms technique is applied to obtain the actual location of the tracked target, whereas the Linear Prediction method is incorporated in the proposed tracking algorithm to predict the location of the moving object in the next frame based on its several past centroid measurements. The Projection Histograms technique coupled with a second order Linear Prediction method has enabled the proposed algorithm to accurately track a single moving object. The potential applicability and efficiency of the proposed tracking algorithm has been validated by good tracking results on several experimental image sequences.

Key words: Motion tracking, projection histograms, linear prediction, frame differencing
Gain Enhancement in L–Band EDFA by Splitting EDF into Two Stages
Authors: Harun Sulaiman Wadi , Ahmad Harith
Published: January 2013

Sebuah esperimen bagi menambah daya pembesaran untuk jalur gelombang panjang (jalur–L) pembesar terdop erbium (PTE) telah didemonstrasi menggunakan reka bentuk yang berbadan dua. Jika dibandingkan dengan pembesar yang berbadan satu, pembesar ini dapat menambah pembesaran untuk isyarat 1580 nm sebanyak 5.5 dB dengan sedikit sahaja penambahan nilai bisingan. Nilai bisingan bertambah sebanyak 0.3 dB kerana kemasukan isolator dalam reka bentuk. Kadar kuasa pam pertama mestilah 33% daripada jumlah keseluruhan kuasa pam untuk nilai optima. Pembesaran maksimum sebanyak 8.3 dB telah diperolehi oleh isyarat 1568 nm semasa kuasa isyarat dan kuasa pam, masing–masing ditetapkan pada 30 dBm dan 92 mW. Keputusan esperimen menunjukkan penggunaan pembesar berbadan dua dapat menjimatkan kos kerana ia menggunakan kuasa pam yang lebih rendah.

Kata kunci: Gentian terdop erbium, pembesar optik, pembesar terdop erbium, jalus LPTE

An experiment on gain enhancement in the long–wavelength band erbium–doped fiber amplifier (L–band EDFA) is demonstrated using a dual stage configuration. Compared to a conventional single–stage amplifier, the small signal gain for a 1580 nm signal can be improved by 5.5 dB without paying much noise figure penalty. The corresponding noise figure penalty was 0.3 dB due to the insertion loss of the optical isolator. The optimum pump power ratio for the first pump was experimentally determined to be 33%. The maximum gain improvement of 8.3 dB was obtained at a signal wavelength of 1568 nm while signal and total pump powers were fixed at –30 dBm and 92 mW, respectively. These results show that the employment of the dual–stage amplifier system will play an important role in the development of a practical L–band EDFA from the perspective of economical usage of pump power.

Key words: Erbium doped fiber, optical amplifier, L-band EDFA, dual-stage EDFA, amlified spontaneous emission
Neural Network Paradigm for Classification of Defects on PCB
Authors: Heriansyah Rudi , Al-attas Syed Abdul Rahman , Ahmad Zabidi Muhammad Mun´im
Published: January 2013

Satu teknik baru dicadangkan untuk mengkelaskan kerosakan yang boleh terjadi pada PCB menggunakan paradigma rangkaian neural. Algoritma untuk membahagi–bahagikan imej menjadi corak primitif, melingkupi corak primitif berkenaan, penandaan corak, normalisasi corak, dan pengkelasan telah dibangunkan berdasarkan pemprosesan imej morfologi penduaan dan rangkaian neural Learning Vector Quantization (LVQ). Ribuan corak rosak telah digunakan untuk tujuan latihan, dan rangkaian neural diuji untuk menilai prestasinya. Satu imej PCB yang rosak digunakan untuk memastikan teknik yang dicadangkan berfungsi.

Kata kunci: PCB, pengkelasan kerosakan, pemprosesan imej morfologi, LVQ

A new technique is proposed to classify the defects that could occur on the PCB using neural network paradigm. The algorithms to segment the image into basic primitive patterns, enclosing the primitive patterns, patterns assignment, patterns normalization, and classification have been developed based on binary morphological image processing and Learning Vector Quantization (LVQ) neural network. Thousands of defective patterns have been used for training, and the neural network is tested for evaluating its performance. A defective PCB image is used to ensure the function of the proposed technique.

Key words: PCB, defects classification, morphological image processing, LVQ
Initial Result on Electrical Impedance Tomography
Authors: Abdul Rahim Ruzairi , Liew Yi Huei , Chan Kok San , Pang Jon Fea , Leong Chai Lean
Published: January 2013

Electrical Impedance Tomography (EIT) provides a low-cost measurement instrument for monitoring distributions of electrically conducting materials in pipelines and process vessels. This paper describes the development of an eight electrode EIT hardware system test on an 84mm diameter flow pipe. The measurement of two different water pipe conditions will be compared: water-filled only and water-filled with solid object are presented within the boundary of the measurement.
Tahap Kontaminasi Bioearosol: Satu Kajian Kes
Authors: Norafiqah J. , Ahmad M. , Firdausi R.
Published: January 2013

Satu kajian menilai tahap kepekatan bioaerosol di ruangan pejabat telah dijalankan dengan menggunakan teknik persampelan hentaman. Dua pemboleh ubah utama, iaitu kadar alir udara, dan masa persampelan yang optimum ditentukan terlebih dahulu. Kesesuaian pertumbuhan bioaerosol khususnya bakteria dan fungus, juga diuji dengan menggunakan empat jenis agar iaitu nutrient agar, tryptic soy agar, potato dextrose agar dan malt extract agar. Keputusan mendapati bahawa kadar alir persampelan 28 liter per minit bersama masa persampelan selama enam minit dan penggunaan medium tryptic soy agar memberikan keputusan yang terbaik. Hasil kajian menunjukkan korelasi yang amat baik di antara tahap kontaminasi bioaerosol dan bilangan manusia yang terdapat di ruangan pejabat, dengan pekali korelasinya yang amat bererti iaitu r2 = 0.99.

Kata kunci: Kualiti udara dalaman, pencemaran udara dalaman, bioaerosol

A study to evaluate the level of bioaerosol contamination in the office spaces was performed using the impaction sampling technique. Two main variables, i.e. sampling air flow rates and duration as well as the suitability of four agar media i.e. nutrient agar, tryptic soy agar, potato dextrose agar and malt extract agar were predetermined. The data showed that the sampling flow rate of 28 Lpm with a sampling duration of 6 minutes applied on tryptic soy agar presented the best results. The study also revealed that there was a strong correlation (i.e. r2 = 0.99) between bioaerosol contamination level and the number of person in the given sampling location.

Key words: Internal air quality, internal air pollution, bioaerosol
Experimenting a Computer-Based Essay Marking System at Universiti Kebangsaan Malaysia
Authors: Darus Saadiyah , Stapa Siti Hamim , Hussin Supyan
Published: January 2013

Di antara sistem pemarkahan esei berkomputer sedia ada adalah e–rater, Project Essay Grader, Intelligent Essay Assessor, Student Essay Viewer, Intelligent Essay Marking System, Marking dan Methodical Assessment of Reports by Computer. Sistem pemarkahan esei berkomputer adalah perisian yang dapat memberi maklum balas kepada penulis bagaimana untuk meningkatkan mutu penulisan. Kajian ini meneliti samada maklum balas yang diberikan oleh salah satu sistem pemarkahan esei ini berguna kepada 46 orang pelajar di Universiti Kebangsaan Malaysia. Esei pelajar–pelajar ini telah diberi markah di atas talian. Pelajar–pelajar ini dikehendaki untuk mengarang esei dalam Bahasa Inggeris berdasarkan satu topik yang telah diberikan. Selepas itu, mereka dikehendaki untuk memperbaiki esei mereka dengan mengambilkira maklum balas yang diberikan oleh sistem pemarkahan esei berkomputer tersebut dan juga menjawab soal–selidik. Hasil dapatan kajian menunjukkan bahawa walaupun pelajar–pelajar telah memperbaiki esei mereka dengan mengambilkira maklum balas yang telah diberikan, masih ada ruang untuk mereka memperbaiki esei mereka itu. Ini menunjukkan bahawa maklum balas yang diberikan tidak mencukupi untuk meningkatkan lagi mutu penulisan mereka. Hasil dapatan penyelidikan ini dapat diguna pakai dalam membangunkan satu kerangka sistem pemarkahan esei berkomputer untuk penulisan dalam Bahasa Inggeris sebagai bahasa kedua bagi pelajar–pelajar di institusi pengajian tinggi di Malaysia.

Kata kunci: Penilaian esei, bahasa Inggeris sebagai bahasa kedua, pembelajaran bahasa dibantu komputer

Some of the available Computer–Based Essay Marking (CBEM) systems are as follows: e–rater, Project Essay Grader, Intelligent Essay Assessor, Student Essay Viewer, Intelligent Essay Marking System, Marking and Methodical Assessment of Reports by Computer. These systems are computer programs that mark essays and can provide feedback to the writer explaining to a certain extent on how a text can be improved. This study investigates whether feedback given by one of these CBEM systems is useful to fourty–six Universiti Kebangsaan Malaysia students whose essays were assessed online. Students, in a writing course, were required to compose an essay on a specified topic in English. Then, they were required to revise their essays by taking into account feedback given by the CBEM system as well as filling out a questionnaire. The results of the study suggest that although students faithfully revise their essays by taking into consideration feedback given by the CBEM system, there is room for improvement indicating that feedback given by the CBEM system is not sufficient. The results of this particular study will contribute to efforts in developing a framework of a CBEM system for writing in English as a second language at tertiary level of education in Malaysia.

Key words: Writing assessment, english as a second language, computer assisted language learning
Kecerdasan Emosi dan Hubungannya dengan Nilai Kerja
Authors: Mohd. Ishak Noriah , Mustapha Ramlee , Ariffin Siti Rahayah , Syed Hassan Syed Najmuddin
Published: January 2013

Kajian ini bertujuan untuk mengkaji hubungan antara kecerdasan emosi dengan nilai kerja di kalangan guru–guru Maktab Rendah Sains MARA (MRSM). Kajian berbentuk korelasi ini melibatkan 91 orang guru–guru yang mengajar di negeri Melaka. Data telah dikumpulkan menggunakan dua jenis soal selidik iaitu: Soal selidik Emotional Quotient (EQ) dan Nilai Kerja. Data yang dikumpul telah dianalisis menggunakan Pearson Product Moment Correlation untuk melihat hubungan antara kedua–dua pemboleh ubah yang dikaji. Secara umumnya dapatan kajian menunjukkan terdapat hubungan yang signifikan antara kecerdasan emosi dan nilai kerja di kalangan responden. Hubungan yang signikan ini perlu diberi perhatian di dalam corak latihan para pendidik di Malaysia di masa–masa akan datang.
Prediction of Disc Brake Contact Pressure Distributions by Finite Element Analysis
Authors: Abu Bakar Abd.Rahim , Quyang Huajiang
Published: January 2013

Pada masa kini, penentuan taburan tekanan sentuhan dianggap penting dalam kajian terhadap hingar squeal bagi sistem brek cakera. Ini kerana analisis sentuhan merupakan sebahagian daripada prosedur dalam penggunaan kaedah nilaiâ€“eigen komplek. Kaedah ini memerlukan matrik kekakuan yang tidak simetri di mana ia diperolehi hasil daripada kekakuan sentuhan dan juga pekali geseran pada permukaan cakera dan pelapik brek. Kertas keria ini menganalisis taburan tekanan sentuhan pada permukaan brek cakera dan pelapik brek menggunakan model terperinci 3 dimensi yang dibina. Bagi tujuan tersebut, satu program komputer komersial digunakan secara meluas. Kajian ke atas tekanan sentuhan terhadap beberapa kategori model unsur terhingga dilakukan. Model yang memberi hasil keputusan yang praktikal akan dipilih untuk kajian seterusoya. Akhir sekali, beberapa model yang diubahsuai bentuk/struktur dan bahan disimulasikan bagi mendapatkan taburan tekanan sentuhan yang lebih sekata. Ini penting bagi sistem brek kerana taburan yang sekata boleh mengelakkan kehausan pada bahagian tertentu dan seterusnya memanjangkan jangka hayat pelapik brek.

Kata kunci: Kaedah unsur terhingga, brek cakera, kaedah nilai-eigen, taburan tekanan sentuhan, kehausan

In recent years, prediction of contact pressure distributions is regarded as an important step in studying disc brake squeal noise. Contact analysis forms part of the whole procedure in the complex eigenvalue method. The essence of such a method lies in the asymmetric stiffness matrix derived from the contact stiffness and the friction coefficient at the disc/pads interfaces. This paper presents the analysis of the contact pressure distributions at the disc/pad interfaces using a detailed 3â€“dimensional finite element model of a real car disc brake. A generalâ€“purpose commercial software package was utilised and assessed. The paper also investigates different levels in modeling a disc brake and simulating contact pressure distributions. Having obtained the suitable model, prediction of interface pressure distributions on an original disc brake was carried out. Finally, modifications on the geometry and/or materials of disc brake components were performed to search for a more uniform contact pressure distribution. It is believed that a uniform contact pressure distribution could prevent excessive tapered wear on the pads and subsequently could prolong the life of pads.

Key words: Finite element method, disc brake, eigenvalues method, contact pressure distribution, wear
Investigation into the Phase Change of Refrigerant in a Wireâ€“andâ€“Tube Consender of Refrigerator
Authors: Ameen A. , Mollik S. A. , Quadir G. A. , Seetharamu K. N.
Published: January 2013

During the passage of dhe refrigerant through the condenser of a refrigerator, it generally undergoes the processes of desuperheating, condensation and subâ€“cooling. One of dhe important criteria in condenser design is to locate the points where superheated refrigerant vapour changes to saturated vapour and subsequently from wet vapour to saturated liquid. The present paper discusses the analysis of wireâ€“andâ€“tube condenser under normal operating conditions of free convection using FEM where Galerkinâ€™s weighted residual method is used to minimise the errors. Refrigerant Râ€“134a is considered for the study and the condenser components are divided into several elements where the state of refrigerant is predicted. The effects of ambient temperature and mass flow rates of the refrigerant are also determined. This is used to find out the length of tube required for phase change for its initiation and completion. The methodology adopted is validated against dhe simulation data available in the literature for both sensible and latent heat transfer. The analysis also leads to the information about dhe adequacy of the number of tubes for complete condensation of the refrigerant vapour under given operating conditions. It is found that for a certain mass flow rate of refrigerant, subâ€“cooling does not occur at some higher ambient temperatures, thus showing the inefficiencies of the heat exchanger. The methodology can be used as a design tool for the design of wireâ€“andâ€“tube condenser of a small refrigerator. The derating of condenser under abnormal ambient conditions can also be predicted.

Keywords: Wire-and-tube condenser, refrigerator, free convection, finite element method, phase change
Guideline for Improving Capacity of a Job Shop Based on Selected Performance Measures
Authors: Khair Salehun Md. Amirul , Md. Tap Masine , Mohamed Shahroun Awaluddin
Published: January 2013

Syarikat pembuatan bukan sahaja perlu memenuhi keperluan pelanggan seperti penghantaran yang menepati masa tetapi juga perlu memenuhi keperluannya seperti penggunaan mesin yang tinggi dan tahap kerja separa siap yang minimum. Bagi mencapai matlamat ini, syarikat perlu menggunakan strategi yang sesuai. Penggunaan strategi yang sesuai dapat memperbaiki kemampuan syarikat pembuatan untuk memenuhi kehendak pelanggan dan juga kehendak syarikat pembuatan. Kajian ini mengenal pasti lima strategi yang membolehkan bengkel kerja menjadi fleksibel. Kelimaâ€“lima strategi ini merangkumi strategi asas yang melibatkan satu set lengkap mesinâ€“mesin satu operasi hingga ke mesinâ€“mesin berbilang operasi. Setiap strategi dinilai dan satu garis panduan dicadangkan. Hasil kajian menunjukkan bahawa strategi penduaan ialah yang terbaik jika kriteria prestasi yang dikehendaki ialah kelewatan dan kerja separa siap. Tetapi jika kriteria prestasi yang dikehendaki ialah tahap penggunaan mesin, maka strategi penggantian ialah yang terbaik.

Kata kunci: Ukuran prestasi, bengkel kerja, strategi pembuatan

Manufacturing companies are required to fulfill customerâ€™s driven imperatives such as on time delivery as well its own requirements such as high machine utilisation and low work in process. In order to achieve these, manufacturers need to adopt the right manufacturing strategy. Selecting the right manufacturing strategies will improve its capability to meet its customers demand as well as its ovvn limitations. This research identifies five strategies that a job shop may adopt to achieve flexibility in meeting demand. The five strategies ranges from the basic strategy of having a complete set of singleâ€“operation machines to flexible multiâ€“operation machines. Each strategy is evaluated and a set of guideline is proposed. The results show that when job tardiness and workâ€“inâ€“process is the performance criteria, the duplication strategy is the best. However, if the performance criteria is machine utilisation, then the best strategy is the replacement strategy.

Key words: Performance measures, job shop, manufacturing strategy
Building Cost Comparison Between Conventional And Formwork System
Authors: Haron Nuzul Azam , Hassim Salihuddin , Abd. Kadir Mohd. Razali , Jaafa Mohd Saleh
Published: January 2013

Industri binaan di Malaysia kini menyusur ke alam perubahan iaitu daripada industri yang menggunakan teknologi tradisional kepada yang lebih sistematik yang melibatkan jentera. Kaedah baru ini juga dikenali sebagai sistem pembinaan bangunan berindustri. Kaedah baru binaan bangunan ini dapat meningkatkan produktiviti dan kualiti kerja menerusi penggunaan mesin, peralatan yang lebih baik, bahan binaan dan juga diperingkat perancangan projek. Kajian ini amat berguna memandangkan masih belum ada sebarang organisasi yang dapat menyediakan maklumat keperluan seperti perbezaan kos bangunan di antara sistem tradisional dengan sistem bangunan berindustri di dalam industri binaan di Malaysia. Kajian ini menerangkan tentang perbezaan kos bangunan di antara sistem tradisional dengan sistem bangunan berindustri yang terpilih iaitu kaedah acuan. Ia menyediakan maklumat perbezaan kos secara terperinci dengan menunjukkan penjimatan kos di antara kaedah binaan tradisional dengan kaedah acuan. Data telah dikumpul melalui kajian soalâ€“selidik dan juga kajian kes bangunan institusi pengajian. Melalui kaedah ujian statistik â€˜tâ€“testâ€™, didapati terdapat perbezaan yang nyata dalam penjimatan kos antara kaedah binaan tradisional berbanding dengan kaedah acuan.

Kata kunci: Sistem pembinaan bangunan berindustri, kaedah acuan, perbandingan kos bangunan, ujian â€˜t-testâ€™

The Malaysian construction industry is undergoing a transitional change from an industry employing conventional technology to a more systematic and mechanised system. This new system is now known as the industrialised building system (IBS). This new method of construction can increase productivity and quality of work through the use of better construction machinery, equipment, materials, and extensive preâ€“project planning. This study is essential since there is no organised body, which can provide the necessary information on the building cost comparison between the conventional system and industrialised building system in Malaysiaâ€™s construction industry. The study also addresses the building cost comparison of the conventional system and selected formwork system in the industrialised building system. It details out the building cost comparison between the conventional system and the formwork system and indicates which of the two is cheaper. The data were collected through questionnaire survey and case study, which involved institutional buildings. Through the statistical test â€˜tâ€“testâ€™, it is shown that there is a significant difference in cost saving for the conventional system as compared to the formwork system.

Key words: Industrialised building system, formwork system, building cost comparison, â€˜t-testâ€™
Straight Line and Circular Arc Methods for Developing G1 and G2 Involute Curves
Authors: Gobithasan R. , Rofizah R. , Jamaludin M. A.
Published: January 2013

Lengkung polinomial berparameter seperti Bezier, Ball, splinâ€“B dan Splinâ€“B tak seragam digunakan dalam mereka bentuk lengkung bebas. Dalam kajian ini, kami telah mengkategori lengkung di atas sebagai lengkung konvensional. Fleksibiliti lengkungâ€“lengkung tersebut membolehkannya diguna dalam mereka bentuk lengkung secara interakhf. Namun demikian, lengkung konvensional ini tidak boleh diguna untuk mereka bentuk lebuh raya, landasan keretapi dan trajektori robot kerana kelengkungan bertanda bagi lengkungâ€“lengkung tersebut sukar dikawal. Oleh yang demikian, pereka bentuk harus menerapkan proses saksama yang memakan masa. Terdapat juga lengkung tak konvensional yang mudah dikawal dari segi kelengkungan, misalnya lingkaran Euler dan sama sudut equiangular. Walau bagaimanapun, mereka bentuk lengkung tak konvensional melibatkan kamiran Fresnal dan fungsi eksponen masingâ€“masingnya yang mengakibatkan overhed dan implementasi. Kajian ini memperkenalkan dua jenis lengkung yang dijana melalui proses evolutâ€“involut. Lengkung involut jenis pertama dijana menggunakan garis lurus selaku evolut dan dinamakan IFSL. Lengkung involut jenis kedua dijana berdasarkan segmen bulatan dan garis lurus, dan dinamakan IFCA.

Kata kunci: Reka Bentuk Geometri Dibantu Komputer (RGBK), lengkung involut, keselanjaran geometri berdarjah 1 (G1) dan 2 (G2), segmen bulatan, lingkaran

Parametric polynomial curves such as Bezier, Ball, Bâ€“splines, Nonâ€“uniform Bâ€“splines (NURBS) are used for free form curve design. In this paper, we classify these curves as conventional curves. The flexibility of these curves deems suitable for use in the interactive design of curves. On the contrary, these curves cannot be used for highways, railways and robot trajectory designs as the signed curvature of these curves are difficult to control. As a result, the designer has to integrate a time consuming fair process. There are unconventional curves with easy control of the curvature namely, Euler and equiangular spirals. Unfortunately, the formulation of these spirals involves Fresnal integral and exponential functions respectively, which results in extra overhead and implementation. This paper introduces two type of curves which are generated from an evoluteâ€“involute process. The first type of involute curve(s) is generated using straight line(s) as the evolute(s) and named IFSL. The second type of involute curve(s) is generated based on circular arc(s) and a straight line and named IFCA.

Key words: Computer Aided Geometric Design (CAGD), involute curves, geometric continuity of degree 1 (G1) and 2 (G2), circular arcs, spirals
Teaching C Programming with the Aid of an Interpreter â€“ Online Interpreter for Novice C Programmer
Authors: Sankupellay Mangalam , Subramaniam Preshshanan
Published: January 2013

Online Interpreter for Novice C Programmer (IfNCP) ialah pakej perisian pembelajaran bagi seseorang yang baru mula mempelajari bahasa pengaturcaraan C. IfNCP mengunakan antara muka grafik untuk mempertingkatkan pemahaman pengguna. Sistem ini menyediakan persekitaran pembelajaran yang interaktif dengan menggunakan multimedia dan grafik secara online.

Kata kunci: C Programming, interpreter, learning package

Online Interpreter for Novice C Programmer (IfNCP) is intended as an introductory learning package for the beginners of C programming language. IfNCP focuses on the graphical code interpretation to enhance user understanding. The system creates an onâ€“line interactive learning environment using multimedia tools and graphical simulations.

Key words: Bahasa pengaturcaraan C, Interpreter, pakej pembelajaran