bluuebunny/crossref_metadata_2025 huggingface dataset:
Development Of Portable Electronic Nose Device For Perfume Odour Classification
Authors: Che Harun Fauzan Khairi , Ibrahim Nur Atiqah , Mohd Basri Mohd Ariffanan
Published: January 2013

Artikel ini membentangkan pembangunan sebuah hidung elektronik (e–Hidung) mudah alih berdasarkan kad perolehan data National Instrument dan LabView. Kajian ini merangkumi rekabentuk litar e–Hidung yang terdiri daripada pelbagai jenis semikonduktor oksida logam daripada FIGARO sebagai sensor gas. Rintangan dari setiap sensor gas diukur melalui litar arus tetap yang dikawal melalui LabView. Sumber arus tetap digunakan sebagai antara muka elektronik bolehubah yang membolehkan pemetaan voltan keluaran sensor untuk profil rintangan sensor dilakukan secara tepat. Rintangan dari setiap sensor dikira secara tepat dan dipaparkan oleh LabView. Keputusan kajian menunjukkan bahawa e – Hidung yang dihasilkan boleh mengesan dan mengklasifikasikan antara dua jenama terkenal iaitu Body Shop dan Avon. Kaedah analisis komponen utama (PCA) yang digunakan menunjukkan diskriminasi besar iaitu 99.53% untuk bau tersebut. Ini menunjukkan bahawa sistem yang dihasilkan mampu membezakan baud an akan digunakan untuk tugas yang lebih kompleks pada masa akan datang.

Kata kunci: Hidung elektronik; semikonduktor oksida logam; sensor gas; pengecaman corak;

This paper presents the development of a portable electronic nose (e–Nose) based on a National Instrument data acquisition card and LabView. The study includes the design of e–Nose circuits that consist of different types of metal oxide semiconductor from FIGARO as gas sensors. The resistances of each gas sensor are measured through a constant current circuit controlled via LabView. The constant current source is used as an adaptive electronic interface that allows the accurate mapping of the sensor’s voltage output to sensor resistance profiles. The resistance of each sensor is accurately computed and displayed by LabView. The result of the study showed that the created e – Nose can detect and classify between two famous brands Body Shop and Avon. The applied principal component analysis (PCA) method shows great discrimination of 99.53% for the mentioned odour. This suggests that the system is able to discriminate between simple odours and will be use for a more complex task in the future.

Key words: Electronic Nose: metal oxide semiconductor; gas sensor; pattern recognition; PCA
Limit Of Phase Only Approach In Micro–Lens Design
Authors: Jebelli Ali , Abdul Rahim Ruzairi , H. Kazemi Seyed
Published: January 2013

Phase only approach (POA) is generally used to analyze diffractive optical elements (DOEs) such as micro–lenses. We used 3–D finite difference time domain (FDTD) method with perfect matched layer (PML) absorbing boundary conditions to test several micro–lenses that were designed based on phase only approach to evaluate the accuracy of this approach. It is shown that if the focal length is greater than 80λ and 25λ for 2π and 4π phase resets, respectively, the error in the main lobe diffraction efficiency will be less than 10%.

Key words: Phase only approach (POA); diffractive optical elements (DOEs); micro–lens
Controller Design For A Pilot–Scale Heating And Ventilation System Using Fuzzy Logic Approach
Authors: Mohd Subha Nurul Adilla , Rahmat Mohd Fua’Ad , M. Ishaq Kashif
Published: January 2013

Dalam kajian ini, pengawal masukan tunggal logik kabur (SIFLC) direka bentuk dan dilaksanakan ke atas sistem VVS–400 dari Instrutek, Larvik, Norway. VVS–400 ini dimodelkan menggunakan struktur model ARX dan model kotak hitam untuk menerbitkan anggaran model matematik bagi sistem tersebut. Reka bentuk SIFLC menawarkan pengurangan yang signifikan dalam peraturan yang digunakan serta memudahkan proses mengawal parameter kawalan. Untuk mengesahkan keberkesanannya, kaedah pendekatan ini disimulasikan dengan anggaran model matematik bagi sistem VVS–400. Anggaran model matematik ini boleh di terbitkan menggunakan perisian pengenalpastian sistem di dalam Matlab. SIFLC telah memberikan beberapa kebaikan dan pembaikan prestasi jika dibandingkan dengan pengawal logik kabur (CFLC) kerana memerlukan peraturan yang mudah serta usaha yang sangat minimum ketika mengawal parameter kawalan. Ini dapat memendekkan masa pengkomputeran untuk menyelesaikan algoritma pengawal. Dalam simulasi, persamaan SIFLC dan CFLC dapat di lihat pada keluaran sistem. Kedua–duanya menghasilkan keluaran yang hampir sama. Namun, kebaikan SIFLC jelas membuktikan keluaran yang sama dapat dihasilkan dengan sedikit pengubahsuaian dari CFLC.

Kata kunci: Pengawal logik kabur; VVS–400; kaedah jarak bertanda; pengawal masukan tunggal logik kabur; ARX

In this paper, a Single–input fuzzy logic controller (SIFLC) is designed and applied on a nonlinear heating and ventilation plant VVS-400 developed from Instrutek, Larvik, Norway. VVS–400 is modeled using Auto–regressive with exogenous input (ARX) model structure and linear black–box technique. The proposed SIFLC offers significant reduction in rule inferences and simplify the tuning of control parameters. To verify its effectiveness, this control method is simulated with an approximated VVS–400 model. An approximated VVS–400 model is obtained using System Identification toolbox in Matlab. The SIFLC provides several advantages over conventional fuzzy logic controller (CFLC) due to its simple inference rule mechanism, require very minimum tuning effort and minimizing the computational time to accomplish the controller algorithm. Simulations validate the equivalency of both controllers. Results reveal that SIFLC and CFLC have almost similar output performance. However SIFLC requires very minimum tuning effort and has less computational time.

Key words: Fuzzy logic controller; VVS–400; signed distance method; single–input fuzzy logic controller; ARX
Salat And Brainwave Signal Analysis
Authors: W.Mohd Ridzwan W.Mohd Fatihilkamal , Mahmood Nasrul Humaimi , Zakaria Nor Aini , Ali Elia Ameera
Published: January 2013

Solat adalah salah satu cara umat Islam untuk mengabdikan diri kepada Allah. Kajian ini bertujuan untuk mengkaji kesan selepas solat terhadap otak dengan menggunakan Electroencephalograph(EEG) dan kegiatan saraf autonomik. Sebanyak 20 sampel isyarat EEG daripada 5 responden (lelaki berumur di antara 22 hingga 23 tahun) dipilih, dan mereka bebas daripada masalah jantung, paru–paru, metabolik dan penyakit lain yang boleh menggangu kegiatan saraf autonomik. Analisa dilakukan dengan membuat perbandingan di antara sampel EEG bagi dua aktiviti berbeza iaitu aktiviti selepas solat dan aktiviti selepas mendengar muzik menggunakan kaedah analisa prinsip komponen (PCA) dan transformasi fourier (FFT). Hasil analisa ke atas isyarat mendapati amplitud tertinggi pada agihan spektrum kuasa adalah pada jalur gamma bagi EEG berbanding jalur–jalur lain (delta, theta, alpha dan beta) bagi kedua–dua aktiviti. Kajian juga menunjukkan kelima–lima subjek mempunyai jalur gamma yang tinggi selepas solat berbanding selepas mendengar muzik. Keputusan ini mencadangkan, apabila seseorang muslim melakukan solat, mereka akan melupakan seketika masalah mereka dan khusyuk mengadap Allah. Ini dapat membantu memulihkan tekanan yang dialami mereka untuk beberapa ketika, seterusnya lebih bersedia untuk menghadapi segala permasalahan dunia selepas solat.

Kata kunci: Solat; electroencephalograph (EEG); isyarat gelombang otak

Salat is one of the ways for the Muslims to worship ‘Allah’ (God). This study investigates the brainwave signal after salat using Electroencephalograph (EEG) signal analysis and autonomic nervous activity. Twenty samples of EEG signal from five respondents (males with age range from 22 to 23 years old) were selected, and they were all free from cardiac, pulmonary, metabolic and other disease that would cause autonomic nervous system dysfunction. The analysis of the acquired EEG signal is done by comparing the samples of EEG signal between the activities after salat and after listening to the music using Principal Component Analysis (PCA) and Fast Fourier Transform (FFT) method. The highest amplitude of the power spectrum distribution was observed in the gamma band on EEG compared to other bands (delta, theta, alpha and beta) for both activities. It shows that these five subjects have a high gamma band after salat compared to after listening to music. It is suggested that when Muslim perform salat, they tend to forget all the worldly matters and thinks they are standing in front of the ‘Allah’. This eventually help them to break their stress for a few times, hence reducing its intensity to facing the worlds’ matter after salat.

Key words: Solat; electroencephalograph (EEG); brainwave signal
Terrestrial Free Space Optic Propagation Analysis Considering Malaysia Weather Condition
Authors: Wan Ruslan Wan Rizal Hazman , Idrus Sevia Mahdaliza , Ramli Arnidza , Ramli Norhafizah , Mohd Supa’at Abu Sahmah , Mohd Nor Farizal
Published: January 2013

Pemantulan cahaya matahari oleh cermin atau dikenali sebagai heliograf adalah kaedah awal komunikasi optik wayarles (OWC). Sewajarnya, sistem komunikasi moden mendedahkan kadar data yang tinggi di samping kualiti perkhidmatan yang lebih baik berbanding kaedah terdahulu. Sistem komunikasi optic wayarles mempunyai banyak kebaikan dimana ia adalah penting untuk sistem daratan, sebagai contoh penggunaan Optik Ruang Bebas (FSO) di kawasan luar. Di dalam kertas kerja ini, gambaran dan pencirian prestasi sistem Optik Ruang Bebas seperti pelemahan, kadar bit kesalahan (BER), faktor Q dan jenis pengesan yang berguna untuk pengesanan dalam sistem FSO dibentangkan. Sistem telah direkabentuk dan disimulasi untuk perincian prestasi dengan mengambil kira kawasan Subang.

Kata kunci: Pelemahan; kadar bit kesalahan; pengesan foto; faktor Q; sistem daratan

The reflection of sunlight by mirrors or known as the heliograph is an early method of optical wireless communication (OWC). Naturally, modern communication system reveals much higher data rates with better quality of service (QoS) compared to those ancient methods. There are many advantages of OWC which are important for a terrestrial system for example the usage of an outdoor free space optics (FSO) system. In this paper, a description and system performance characterization of the FSO such as attenuation, bit error rate (BER), Q factor and the type of detectors that are highly useful for detection in FSO systems are presented. The system are designed and simulated for performance characterization considering Subang terrestrial.

Key words: bit error rate; photodetector; Q factor; terrestrial system
Ultrasonic Tomography System In Liquid – Gas Flow Monitoring
Authors: Pusppanathan Jaysuman , Abdul Rahim Ruzairi , Rahiman Mohd Hafiz Fazalul
Published: January 2013

Suatu kajian proses tomografi ultrasonik telah dijalankan untuk mengenal pasti dan mengukur pengaliran dua fasa iaitu campuran fasa cecair dan gas. Sistem ini telah dibina menggunakan lapan unit penderia ultrasonik mempunyai dua fungsi (pemancar atau penerima isyarat) pada suatu masa. Berbanding dengan penggunaan penderia ultrasonik yang lazim digunakan, penderia ultrasonik dwi – fungsi ini mampu menberi pengukuran dan imej tomogram yang sama kualitinya malah ia mempunyai lebih banyak kelebihan dan lebih tepat. Disebabkan beberapa kebatasan penggunaan penderia ultrasonik yang berfungsi secara individu, kajian ini dijalankan supaya tidak mengganggu proses pengaliran aliran dalaman paip dan sebagai satu pendekatan alternitif menggunakan penderia ultrasonik dwi – fungsi tersebut. Dengan lapan unit penderia ini, litar – litar pengukuran, sistem perolehan data dan algoritma pembentukan imej yang bersesuaian telah direalisasikan. Keputusan yang diperolehi hasil dari kajian ini menunjukkan tomografi ultrasonik menggunakan penderia dwi – fungsi berjaya memaparkan ciri – ciri dalamaan bagi pengaliran dua fasa ini iaitu cecair dan gas. Sistem sebegini sangat berguna dalam bidang campuran bahan cecair kimia atau penghantaran cecair di kawasan luar pantai.

Kata kunci: Ultrasonik; tomografi; sistem pengaliran; cecair dan gas; penderia ultrasonik

This research was carried out to measure two phase liquid – gas flow regime by using a dual functionality ultrasonic transducer. Comparing to the common separated transmitter – receiver ultrasonic pairs transducer, using dual functionality ultrasonic transceiver is capable to produce same measurement results hence further improvised and contributes to the hardware design improvement and system accuracy. Due to the disadvantages and the limitations of the separated ultrasonic transmitter – receiver pair, therefore this thesis presents a non–invasive of ultrasonic tomography system using ultrasonic transceiver as an alternative approach. By using 8 units of ultrasonic transceivers, the electronic measurement circuits, the data acquisition system and suitable image reconstruction algorithms, the measurement of a liquid/gas flow was realized. The system is capable of visualizing the internal characteristics of liquid and gas flow and provides the concentration profile for the corresponding liquid and gas flow. This system is useful in monitoring of liquid/gas flow in flow regime, chemical mixture transportation or fluid transportation at sub sea oil fields.

Key words: Ultrasonic; tomography; flow system; liquid gas; transceiver
Image Reconstruction Algorithms For Ultrasonic Tomography
Authors: Rahiman Mohd Hafiz Fazalul , Abdul Rahim Ruzairi , Abdul Rahim Herlina
Published: January 2013

Kertas ini membincangkan algoritma pembangunan imej bagi kegunaan dalam tomografi ultrasonik. Terdapat tiga jenis algoritma pembangunan iaitu Linear Back Projection, Hybrid Reconstruction dan Hybrid Binary Reconstruction. Algoritma tersebut telah diuji ke atas sistem tomografi ultrasonik berdasarkan kepada beberapa bayang yang telah dikenalpasti dan objek–objek sebenar. Prestasi algoritma tersebut telah di analisa dan bincangkan pada bahagian akhir kertas ini.

Kata kunci: Algoritma pembangunan; tomografi ultrasonic; pemprosesan image; mabuk

This paper presented image reconstruction algorithms for use in ultrasonic tomography. There are three types of reconstruction algorithms namely Linear Back Projection, Hybrid Reconstruction and Hybrid Binary Reconstruction. The algorithms have been evaluated on ultrasonic tomography system based on several known phantoms and real objects. The performance of the algorithms have been analysed and discussed at the end of the paper.

Key words: Reconstruction algorithm; ultrasonic tomography; image processing
Function Minimization In DNA Sequence Design Based On Binary Particle Swarm Optimization
Authors: Ibrahim Zuwairie , Khalid Noor Khafifah , Sheng Ismail , Buyamin Salinda , Md. Yusof Zulkifli , Muhammad Mohd Saufee
Published: January 2013

In DNA based computation and DNA nanotechnology, the design of good DNA sequences has turned out to be an elementary problem and one of the most practical and important research topics. Although the design of DNA sequences is dependent on the protocol of biological experiments, it is highly required to establish a method for the systematic design of DNA sequences, which could be applied to various design constraints. Basically, the fitness of DNA sequences can be evaluated using four objective functions, namely, similarity, Hmeasure, continuity and hairpin. In this paper, binary particle swarm optimization (BinPSO) is proposed to minimize those objective functions individually, subjected to two constraints: melting temperature and GCcontent. An implementation of the optimization process is presented using 20 particles and the results obtained shows the correctness of PSO computation, where the minimized values for each objective can be achieved.

Kata kunci: DNA sequence design; binary particle swarm optimization; objective function; constraints; fitness function

Dalam DNA berasaskan pengiraan dan nanoteknologi DNA, reka bentuk jujukan–jujukan DNA baik telah menjadi satu masalah asas dan salah satu topik–topik penyelidikan penting dan paling praktikal. Walaupun reka bentuk DNA berjujukan adalah bergantung kepada pada protokol eksperimen biologi, ia amat diperlukan bagi mewujudkan satu kaedah untuk reka bentuk bersistem DNA berjujukan, yang boleh digunakan untuk pelbagai reka bentuk kekangan. Pada asasnya, kecergasan DNA berjujukan boleh dinilaikan menggunakan empat fungsi–fungsi objektif, iaitu, similarity, Hmeasure, continuity dan hairpin. Dalam kertas kerja ini, pengoptimuman kerumunan zarah perduaan (BinPSO) dicadangkan untuk meminimumkan fungsi–fungsi objektif tersebut secara individu, tertakluk kepada dua kekangan: melting temperature dan GCcontent Satu perlaksanaan proses pengoptimuman dibentangkan menggunakan 20 zarah–zarah dan keputusan yang diperolehi menunjukkan kebenaran pengiraan PSO, di mana nilai–nilai yang minimum untuk setiap objektif dapat dicapai.

Key words: Reka bentuk jujukan DNA; pengoptimuman kerumunan zarah perduaan; fungsi objektif; kekangan; fungsi kecergasan
Improvement Of Load Frequency Control By Using Self–Tuning Controller
Authors: Sheikh M.R.I. , Anower M.S , Rabbani M. G.
Published: January 2013

Since a Superconducting Magnetic Energy Storage (SMES) unit with a self–commutated converter is capable of controlling both the active and reactive powers simultaneously and quickly, increasing attention has been focused recently on power system stabilization by SMES control. This paper presents a novel control method of SMES with a self-tuned Fuzzy Proportional Integral (FPI) controller associated with the Automatic Generation Control (AGC) for improving Load Frequency Control (LFC) in a single area power system. Boiler dynamics and nonlinearities such as governor dead band (DB) and generator rate constraints (GRC) are considered in the developed comprehensive mathematical model of a single area isolated power system. The effects of the self–tuning configuration of FPI controller in AGC on SMES control is compared with that of fixed gain PI controlled AGC. It is seen that with addition of FPI controller, SMES can perform a more effective primary frequency control for single area power system.

Key words: Load frequency control; single area power system; automatic generation control; superconducting magnetic energy storage unit; fuzzy proportional integral controller
Infrared Tomography Sensor Configuration Using 4 Parallel Beam Projections
Authors: Md.Yunos Yusri , Mansor Muhammad Saiful Badri , Nor Ayob Nor Muzakkir , Fea Pang Jon , Abdul Rahim Ruzairi , San Chan Kok
Published: January 2013

Penyelidikan ini menunjukkan konfigurasi sensor tomografi optik dengan penggunaan pemancar inframerah dan foto transistor. Geometri unjuran sensor adalah berdasarkan kombinasi dua unjuran oktagon dan dua unjuran garis lurus tatasusunan. Sebuah perlengkapan direka untuk memegang keseluruhan pasangan pemancar–penerima secara selari. Pemilihan foto transistor juga dijelaskan supaya pembangunan sensor tomografi adalah bebas dari bacaan yang tidak diingini daripada persekitaran sekeliling. Penulisan ini juga menerangkan perkara–perkara yang perlu dipertimbangkan untuk pembangunan sensor tomografi optikal.

Kata kunci: Inframerah; tomografi optikal

This paper represents the configuration of optical tomography sensor by using infrared emitter and phototransistor. The projection geometry of the sensor is based on the combination of two orthogonal and two rectilinear projections arrays. A fixture is designed for holding all emitter–receiver pairs in parallel. Selection of phototransistor is explained so that the tomography sensor developed is free of noise cause by surrounding environment. This paper describes all points to be considered when design an optical tomography sensor.

Key words: Infrared; optical tomography
Smart Electronic Chess Board Using Reed Switch
Authors: Mahmood Nasrul Humaimi , Che Ku Long Che Ku Mohd Salahuddin
Published: January 2013

This paper introduces the used of reed switch to detect the chess pieces that played on the electronic chessboard. During the tournament, audiences are not allowed to watch the game too close with all chess players to avoid the chess players lost their concentration. Hence, a system that can automatically project the chess players’ game is needed. This digital electronic chessboard can display the chess game on the computer screen with integration to other components such as microcontroller, chess clock and software application. The result showed that the reed switch could be one of the solutions to reduce the expensive sensor cost of existing digital electronic chess set.

Key words: Reed switch; digital electronic hessboard; electronic chess set; microcontroller
Comparative Study Of Offset Time Schemes Over Optical Burst Switching (OBS)
Authors: A. Yayah Abdul Salam , Ismail Abdul Samad , Al–Shargabi Mohammed. A. , Idrus Sevia M.
Published: January 2013

Penggunaan internet yang meluas dan berterusana menyebabkan kenaikan trafik dalam talian. Teknik Optical Burst Switching (OBS) boleh dikatakan sebagai penyelesaian kepada masalah trafik di dalam rangkaian internet. Namun demikian, terdapat beberapa isu dalam rangkaian OBS. Salah satu isunya adalah untuk meminimakan offset masa tunda dan untuk mengatasi masalah ini, terdapat banyak penyelidikan dilakukan menggunakan berbagai cara dan teknik. Laporan ini menyediakan penerangan mengenai skema yang telah digunakan disamping menghuraikan mengenai kelebihan dan kekurangan skema yang telah sedia ada.

Kata kunci: OBS; offset time

The dramatic and continuous use of the Internet has increased the network traffic that is needed to be transferred through the Internet network. Optical Burst Switching (OBS) has met the requirements of such demands and is considered as a solution of the issues present in Internet networks. However, there are still some issues in OBS network have not been solved. Minimizing offset time delay is one of these concerns and a lot of research has been introduced in order to solve this issue through using various ways or schemes. In this paper, a description of these schemes and their advantages and disadvantages is presented.

Key words: OBS; offset time
Determination Of Fwhm For Solition Trapping
Authors: Afroozeh A. , Amiri I. S. , Ali J. , Yupapin P. P.
Published: January 2013

In this study an interesting system in which a bright and dark soliton pulse can be stopped inside a nonlinear waveguide is presented. Here, we propose a system consisting of a series of ring resonators for optical trapping within a nonlinear waveguide. The bright and dark solitons can be controlled and slowed down within the waveguide. The FWHM for the output signals are calculated and used as an optical memory. Bright and dark soliton behaviors within a micro and nano ring resonator are also investigated and described. The required pulse is filtered and amplified, can be controlled and localized within the system. The localized bright and dark solitons are stopped by controlling the input power, which means that the photon stopping can be controlled by light in a ring resonator.

Key words: Dark soliton; bright soliton; nonlinear nano waveguide; stopped light
Review Of Semiconductor Optical Amplifier (SOA) Functionalities
Authors: Mahad Farah Diana , M. Supa’at Abu Sahmah , Idrus Sevia Mahdaliza , Forsyth David
Published: January 2013

Penguat optik separuh–pengalir (SOA) adalah sebuah peranti optik yang sentiasa meningkat penggunaannya di dalam rangkaian perhubungan optik. SOA yang berdasarkan subsistem telah terbukti kebolehannya dalam pelaksanaan SOA di dalam banyak penggunaan praktikal dan fungsi. Di dalam kertas kerja ini, kefungsian SOA yang berdasarkan sambutan lelurus dan ketidak–lelurusan telah dikaji. Penggunaan asas SOA di dalam sistem perhubungan optik telah dibincangkan: pascapenguat (atau penguat penggalak), penguat sebaris and prapenguat. Selain itu, pelbagai skim penukaran panjang gelombang telah ditinjau berdasarkan SOA ketidaklelurusan seperti pemodulatan gandaan–silang (XGM), pemodulatan fasa–silang (XPM) dan pencampuran empat–gelombang (FWM). Selain penukaran panjang gelombang dan penguatan, SOA juga boleh digunakan sebagai komponen di dalam pensuisan optik, penggetan dan sistem “hirisan–spektrumž. Oleh kerana itu, SOA telah menyediakan pelbagai penyelesaian yang cekap dan kos–berkesan bagi menjanakan kepentingan terkini dalam pelbagai penggunaan sistem perhubungan optik di masa depan.

Kata kunci: Penguat optik separa–pengalir; amplifications; wavelength conversion; switching; spectrum–sliced

The Semiconductor Optical Amplifier (SOA) is a photonic device which is increasingly being utilized in many modern state–of–the–art optical communication networks. The SOA provides numerous highly efficient and cost–effective solutions to many network problems, and therefore generates great new interest for a wide variety of applications in future all optical communication systems. SOA based subsystems have been proven to have the capability of implementing the SOA into many practical applications and functions. In this paper, the functionalities of the SOA, based on linear and non-linear responses, are reviewed. The basic applications of SOAs in optical communication systems are also discussed: as post–amplifier (or booster amplifier), in–line amplifier and as preamplifier. In addition, various wavelength conversion schemes based on the inherent nonlinearities of the SOA are reviewed: cross gain modulation (XGM), cross phase modulation (XPM) and four–wave mixing (FWM). Besides wavelength conversion and amplification, SOAs can also be used for future applications such as optical switching, gating and “spectrum–sliced” systems; and these are also reviewed.

Key words: Semiconductor optical amplifier; amplifications; wavelength conversion; switching; spectrum–sliced
Performance Analysis Of Hybrid Optical–Wireless Access Network Physical Layer
Authors: Shaddad Redhwan Q. , Mohammad Abu Bakar , Al–Hetar Abdul Aziz M. , M. Idrus Sevia
Published: January 2013

The hybrid optical–wireless access network (HOWAN) is a favorable architecture for next generation access network. It is an optimal combination of an optical backhaul and a wireless front–end for an efficient access network. In this paper, the new architecture of the HOWAN is proposed and designed based on both a wavelengths division multiplexing/time division multiplexing passive optical network (WDM/TDM PON) at the optical backhaul and a worldwide interoperability for microwave access (WiMAX) technology at the wireless front–end. It is demonstrated 2 Gb/s for downstream/upstream can be achieved at optical backhaul along 20 km of single mode fiber (SMF) for each wavelength channel with bit error rate (BER) of 10–9, at a data rate of 30 Mb/s per Base Station (BS) along a 5 km outdoor wireless link with BER of 10–5.

Key words: Hybrid optical–wireless access network (HOWAN); Passive optical network (PON); Wavelength division multiplexing (WDM); Wireless mesh network (WMN); Orthogonal frequency division multiplexing (OFDM)
Molecular Transporter System For Qubits Generation
Authors: Amiri I. S. , Afroozeh A. , Bahadoran M. , Ali J. , Yupapin P. P.
Published: January 2013

A molecular cryptography technique using optical tweezers, is proposed. The optical tweezer transports the molecules in the communication system. The optical tweezer generated by the dark soliton is in the form of a potential well. The dark soliton propagates inside nonlinear microring resonator (NMRR). Transportation of molecules is implemented when the dark soliton is used as input pulse. The input bright soliton control the output signal at the drop port of the system. Output optical tweezers can be connected to the quantum signal processing system consisting of transmitter and the receiver. The transmitter is used to generate the high capacity quantum codes within the series of MRR’s and an add/drop filter. The receiver will detect the encoded signals known as quantum bits. The transmitter will generate the entangled photon pair which propagates via an optical communication link. Here the smallest optical tweezer with respect to the full width at half maximum FWHM is 17.6 nm in the form of potential well is obtained and transmitted through quantum signal processor via an optical link.

Key words: Internet security; optical tweezers; quantum cryptography; quantum signal processing; entangled photon pair
Vibration-Based Damage Detection Using Modal Data: An Experimental Verification
Authors: Tong Khoon Hong , Bakhary Norhisham , Mutalib Azrul , Anang Rosli
Published: January 2013

Sifat dinamik adalah fungsi bagi ciri-ciri fizikal. Sejak 20 tahun yang lalu, banyak usaha telah dibuat dalam menyiasat hubungan antara kerosakan struktur dan parameter modal. Banyak kaedah telah diperkenalkan dari kaedah langsung hingga penggunaan algoritma optimuman. Kebanyakan penulis membuat kesimpulan bahawa sifat-sifat dinamik boleh digunakan sebagai penunjuk kerosakan. Walau bagaimanapun, kebanyakan kerja tersebut telah disahkan melalui model simulasi dan bukannya pengesahan uji kaji. Oleh itu, kajian ini bertujuan untuk menyiasat kecekapan kelengkungan mod dan frekuensi tabii dalam pengesanan kerosakan melalui contoh uji kaji rasuk keluli keratan segi empat berongga. Tujuh senario kerosakan disimulasikan pada spesimen dengan menggunakan potongan giling bagi lokasi kerosakan dan keterukan yang berbeza. Kajian kepekaan kepada indeks kerosakan kelengkungan modal dilakukan dan isu-isu yang berkaitan dengan penggunaan data modal dibincangkan. Keputusan menunjukkan bahawa frekuensi tabii adalah penunjuk kewujudan kerosakan yang sensitif. Sementara, kebolehpercayaan kelengkungan modal pula adalah agak terhad dan amat bergantung kepada ketepatan pengukuran.

Kata kunci: Pemantauan kesihatan struktur; ujian modal; data modal

Dynamic properties are the functions of physical properties. Over the past 20 years, considerable efforts have been made in investigating the relationship between structural damage and modal parameters. Many methods have been introduced ranging from direct methods to application of optimization algorithms. Most of the authors concluded that the dynamic properties are feasible as damage indicators. However, most of the works are validated through analytical models instead of experimental verification. Thus, this study aims to investigate the efficiency of modal curvature and natural frequencies in damage detection through an experimental example of a rectangular hollow section steel beam. Seven damage scenarios are simulated on the specimen using grinder cuts for different damage location and severity. Sensitivity study on the damage index of modal curvature is performed and issues related to the application using modal data are discussed. The results show that natural frequency is a sensitive damage existence indicator. While, the reliability of modal curvature is quite limited and very much depending on the accuracy and precision of measurements.

Key words: Structural health monitoring; modal testing; modal data
Mesh Simplification - A New Approach
Authors: Ali Siti Khadijah , O. K. Rahmat Rahmita Wirza , Khalid Fatimah , Ng Seng Beng
Published: January 2013

Pemudahan permukaan telah menjadi topik kajian yang menarik dalam beberapa dekad ini. Sesetengah penyelidik memperkenalkan kaedah yang baharu manakala penyelidik lain melakukan pengubahsuaian ataupun penambahbaikan terhadap kaedah yang sedia ada. Walau bagaimanapun, model yang telah dipermudahkan mempunyai kecenderungan untuk kehilangan sebahagian daripada bentuk asalnya. Dalam pada itu, untuk mengatasi segala masalah ini, satu algoritma baru diperkenalkan, di mana formula nisbah digunakan untuk mengenal pasti calon elemen yang layak untuk dibuang. Elemen yang digunakan dalam algoritma baru ini adalah segitiga. Keputusan kajian menunjukkan bahawa algoritma yang dicadangkan dapat mengekalkan bentuk permukaan model asal.

Kata kunci: Permudahan permukaan; persamaan rasional; berjenis; segitiga kontraksi; penipisan permukaan

Mesh simplification has become an interesting research area over the past few decades. Some researchers have introduced various new methods while others have made some modifications or improvements to the existing method. However, the modified model tended to lose some of its original shape. Hence, to solve these arising problems, a new decimation algorithm is introduced, in which rational equation is used to select elements as candidates to be removed. The proposed algorithm also uses triangular mesh as the element. The results show that our proposed algorithm can preserve the shape of the mesh.

Key words: Mesh simplification; rational equation; manifold; triangle contraction; mesh decimation
The Validity And Reliability Of Generic Skills Instrument For Lecturer Evaluation Of Pre-University Students Using The Measurement Model In Confirmatory Factor Analysis (CFA)
Authors: Ariffin Siti Rahayah , Najmudin Nur Ashiqin , Idris Rodiah , Najieb Badib Ayesha Abdullah , Rashid Nur Aidah
Published: January 2013

Tujuan kajian ini adalah untuk mengukur kesahan Instrumen Kemahiran Generik Penilaian Pensyarah (IKGPP). Instrumen ini mengandungi 77 item dan ditadbirkan oleh 2 orang pensyarah kepada 98 pelajar pra-universiti di salah sebuah kolej matrikulasi Kementerian Pelajaran Malaysia. Instrumen ini direka bentuk untuk mengukur 9 konstruk kemahiran iatu Komunikasi; Kepemimpenan; Kerja Berpasukan; Pembelajaran Sepanjang Hayat dan Pengurusan Maklumat; Pemikiran Kritis dan Penyelesaian Masalah; Etika dan Moral Profesionalisme; Keusahawanan; Pengurusan dan Tangungjawab Sosial. 16 item telah digugurkan dengan menggunakan Model Rasch dalam Perisian Winstep 3.64.2. Sejumlah 61 item yang dikekalkan dianalisis kesahannya dengan menggunakan model pengukuran dalam Confirmatory Factor Analysis (CFA) dengan perisian AMOS 5.0. Nilai indeks Comparative Fit Index (CFI >= 0.9), Tucker Lewis Index (TLI >= 0.9), dan RMSEA ( 0.9. Manakala nilai RMSEA berada pada julat < 0.08 yang merupakan indek yang boleh diterima. Kesemua 61 item dapat dikekalkan dengan membuat correlation di antara item-item di dalam konstruk-knostruk tersebut. Instrumen terkini IKGPP ini boleh digunakan untuk menilai pelajar pra-universiti di kolej matrikulasi.

Kata kunci: Kemahiran generic; model persamaan struktural (SEM); model pengukuran, confirmatory factor analysis (CFA); instrumen kemahiran generik penilaian pensyarah (IKGPP)

The purpose of this study is to measure the validity of the Generic Skills Instrument for Lecturer Assessment (IKGPP). The research instrument contains 77 items and was administered by two lecturers on 98 pre-university students at a Ministry of Education Matriculation College. The instrument was designed to measure nine skill constructs, i.e. Communication; Leadership; Teamwork; Lifelong Learning and Information Management; Critical Thinking and Problem Solving; Ethics and Moral Professionalism; Entrepreneurship; Management and Social Responsibility. Data analyses were done using the Rasch Model, of which Winstep 3.64.2 was used. 16 items were eliminated and the remaining 61 items were analyzed for validity using the measurement model in Confirmatory Factor Analysis (CFA) with the AMOS 5.0. The index values for Comparative Fit Index (CFI >= 0.9), Tucker Lewis Index (TLI >= 0.9), and RMSEA ( 0.9 range. The RMSEA value is in the acceptable range of < 0.08. All 61 items were retained by correlating the items in the constructs. The current IKGPP instrument could be used to assess the pre-university students in matriculation college.

Key words: Generic skills; structural equation model (SEM); measurement model; confirmatory factor analysis (CFA); generic skills instrument for lecturer assessment (GeSILA)
Photocatalytic Oxidation of Methyl Orange Dye over Titania Nanocatalyst
Authors: Ngadi Norzita , Nosri Aisyah
Published: January 2013

In this study, the ability of titania dioxide nanoparticles (TiO ) to remove methyl orange dye in aqueous solution was investigated. The effects of TiO dosage (i.e. 0.4, 0.8, 1.2, 1.6 and 2 g), pH (i.e. 4, 6, 7, 8, 10 and 12) temperature (30, 40 and 50°C) and light source (i.e. UV, sunlight and dark room) on the removal of methyl orange dye were studied. The experiments were conducted under the UV light irradiation with the presence of air bubbling. The samples were analyzed using UV-vis spectrophotometer at wavelength of 467 nm. From this study, it was found that the TiO dose, pH, temperature and the presence of light had a strong effect on the removal of dye. The removal of dye was optimum at TiO loading of 2.0 g, pH of 4, temperatureof 30°C and under UV light condition.

Dalam kajian ini, kebolehupayaan titanium dioksida (TiO ) untuk menyingkirkan pewarna metil oren daripada larutan telah dikaji. Kesan-kesan dos TiO (iaitu 0.4, 0.8, 1.2, 1.6 and 2 g ), pH (iaitu 4,6,8,10 dan 12) suhu (iaitu 30, 40 and 50°C) dan sumber cahaya (UV, cahaya matahari dan bilik yang gelap) terhadap penyingkiran pewarna metil oren telah dikaji. Eksperimen telah dijalankan di bawah radiasi UV dengan kehadiran oksigen terlarut. Sampel telah dianalisa menggunakan UV-vis spektrofotometer dengan panjang gelombang 467 nm. Daripada kajian ini, telah didapati bahawa dos TiO , pH, suhu dan kehadiran cahaya memberikan kesan yang ketara terhadap penyingkiran pewarna. Penyingkiran pewarna adalah paling optimum pada dos TiO, 2 g, pH, 4, suhu, 30°C dan dibawah cahaya UV.
Experimental Design and Performance Analysis in Plasma Arc Surface Hardening
Authors: Ismail Mohd Idris Shah , Taha Zahari , Abdul Shukor Mohd Hamdi
Published: January 2013

In this paper, the experimental design by using the Taguchi method was employed to optimize the processing parameters in the plasma arc surface hardening process. The evaluated processing parameters are arc current, scanning velocity and carbon content of steel. In addition, the significant effects of the relation between processing parameters were also investigated. An orthogonal array, signal-to-noise (S/N) ratio and analysis of variance (ANOVA) were employed to investigate the effects of these processing parameters. Through this study, not only the increasing in hardened depth and improvement in surface roughness, but the parameters that significantly affect on the hardening performance were also identified. Experimental results showed the effectiveness of this approach.

Dalam kertas kerja ini, reka bentuk ujikaji menggunakan kaedah Taguchi digunakan untuk mengoptimumkan parameter pemprosesan dalam proses arka plasma pengerasan permukaan. Parameter pemprosesan yang dinilai adalah arus arka, halaju imbasan dan kandungan karbon dalam keluli. Sebagai tambahan, kesan-kesan penting yang lain seperti hubungan di antara parameter pemprosesan juga diselidiki. Tatasusunan ortogon, nisbah signal to noise (S/N) dan analisis varians (ANOVA) digunakan untuk mengkaji kesan parameter pemprosesan ini. Melalui kajian ini, bukan sahaja kedalaman pengerasan bertambah dan kekasaran permukaan lebih baik, malah parameter pemprosesan yang nyata sekali menpengaruhi prestasi pengerasan dikenal pasti. Hasil percubaan mengesahkan keberkesanan pendekatan ini.
Reverse Micelle Liquid-Liquid Extraction of Bovine Serum Albumin and Lysozyme
Authors: Mohd Setapar Siti Hamidah , Mohamad Aziz Siti Norazimah , Joanne Constantine
Published: January 2013

Reverse micelle extraction by using Sodium bis (2-ethylhexyl) Suffoccinate (AOT) of protein bovine serum albumin (BSA) and lysozyme was investigated in this research. Study of factors affecting the surfactant concentration and pH of aqueous for both forward and backward extraction process was performed in the research. The BSA concentrations were characterized by using the UV- spectrophotometer at wavelength, λ = 280 nm. The result indicated that the extraction percentage of lysozyme was higher than BSA in forward transfer for both parameters; however BSA demonstrated a better extraction performance in backward extraction process. The maximum lysozyme extracted in the forward extraction process was at 60 mM of surfactant concentration while for BSA was 100 mM since BSA is a bulky molecule and the size is larger than of lysozyme.

Pengekstrakan misel terbalik dengan menggunakan Sodium bis (2-ethylhexyl) Suffoccinate (AOT) untuk protein bovine serum albumin (BSA) dan lysozyme disiasat dalam penyelidikan ini. Kajian tentang faktor-faktor yang mempengaruhi kepekatan surfaktan dan pH akueus untuk proses pengekstrakan hadapan dan ke belakang telah dijalankan. Kepekatan BSA telah dicirikan dengan menggunakan spektrofotometer UV pada panjang gelombang, λ = 280 nm. Hasil kajian telah menunjukkan bahawa peratusan pengekstrakan lysozyme adalah lebih tinggi daripada BSA bagi pemindahan ke hadapan untuk kedua-dua parameter, namun begitu BSA menunjukkan prestasi pengekstrakan yang lebih baik di dalam proses pengekstrakan kebelakang. Jumlah maksimum lysozyme yang diekstrak di dalam proses pengekstrakan ke hadapan adalah 60 mM kepekatan surfaktan manakala bagi BSA adalah 100 mM disebabkan BSA adalah molekul yang sangat besar dan ia mempunyai saiz yang lebih besar berbanding daripada lysozyme.
A mass conservation‐based optical flow method for cardiac motion correction in 3D‐PET
Authors: Dawood Mohammad , Gigengack Fabian , Jiang Xiaoyi , Schäfers Klaus P.
Published: January 2013

Purpose:

Cardiac positron emission tomography (PET) images usually show two kinds of artifacts: the limited resolution of PET leads to partial volume effects and the motion of the heart induces blurring. These phenomena degrade the PET images and induce errors in the quantification. One method of reducing this problem is to use gated PET data. However, the reduction of information per phase leads to an increase in noise on the reconstructed images. Alternatively, the PET data have to be corrected for motion and partial volume effects.

Methods:

Optical flow methods have been shown to accurately estimate the motion between PET image frames. These methods assume that the brightness of the objects remains constant between the frames. This condition is not fulfilled in cardiac PET data because the brightness of the cardiac muscle tissue (myocardium) is not accurately resolved due to the partial volume effect. Therefore, the use of a newly developed optical flow method based upon the conservation of mass condition is proposed to correct the cardiac PET data. Mass conservation is applicable to PET images as the total activity in the field of view may be assumed to remain almost constant, if the data are precorrected for radioactive decay. Two variants of the method using the quadratic and the nonquadratic penalization are presented. The methods were evaluated with respect to correlation coefficient, myocardial thickness and the blood pool activity in the left ventricle on phantom data and on 14 patient image volumes.

Results:

The proposed methods showed that the cardiac motion can be efficiently corrected despite partial volume effects. The correlation coefficient between the image volumes increased from 0.87 to 0.98 on average. The change in myocardial thickness was reduced from 28% to 3%. The variation in blood pool activity was reduced from 80% to 8%. The algorithm needed only about 4 s for execution.

Conclusions:

A mass preserving optical flow method of cardiac motion correction in 3D PET data has been presented and tested on phantom as well as patient data. The results show that the motion was corrected for all datasets effectively.
Calibrating page sized Gafchromic EBT3 films
Authors: Crijns W. , Maes F. , van der Heide U. A. , Van den Heuvel F.
Published: January 2013

Purpose:

The purpose is the development of a novel calibration method for dosimetry with Gafchromic EBT3 films. The method should be applicable for pretreatment verification of volumetric modulated arc, and intensity modulated radiotherapy. Because the exposed area on film can be large for such treatments, lateral scan errors must be taken into account. The correction for the lateral scan effect is obtained from the calibration data itself.

Methods:

In this work, the film measurements were modeled using their relative scan values (Transmittance,T). Inside the transmittance domain a linear combination and a parabolic lateral scan correction described the observed transmittance values. The linear combination model, combined a monomer transmittance state (T0) and a polymer transmittance state (T∞) of the film. The dose domain was associated with the observed effects in the transmittance domain through a rational calibration function. On the calibration film only simple static fields were applied and page sized films were used for calibration and measurements (treatment verification). Four different calibration setups were considered and compared with respect to dose estimation accuracy. The first (I) used a calibration table from 32 regions of interest (ROIs) spread on 4 calibration films, the second (II) used 16 ROIs spread on 2 calibration films, the third (III), and fourth (IV) used 8 ROIs spread on a single calibration film. The calibration tables of the setups I, II, and IV contained eight dose levels delivered to different positions on the films, while for setup III only four dose levels were applied. Validation was performed by irradiating film strips with known doses at two different time points over the course of a week. Accuracy of the dose response and the lateral effect correction was estimated using the dose difference and the root mean squared error (RMSE), respectively.

Results:

A calibration based on two films was the optimal balance between cost effectiveness and dosimetric accuracy. The validation resulted in dose errors of 1%–2% for the two different time points, with a maximal absolute dose error around 0.05 Gy. The lateral correction reduced the RMSE values on the sides of the film to the RMSE values at the center of the film.

Conclusions:

EBT3 Gafchromic films were calibrated for large field dosimetry with a limited number of page sized films and simple static calibration fields. The transmittance was modeled as a linear combination of two transmittance states, and associated with dose using a rational calibration function. Additionally, the lateral scan effect was resolved in the calibration function itself. This allows the use of page sized films. Only two calibration films were required to estimate both the dose and the lateral response. The calibration films were used over the course of a week, with residual dose errors ⩽2% or ⩽0.05 Gy.
Technical Note: Building a combined cyclotron and MRI facility: Implications for interference
Authors: Hofman Mark B. M. , Kuijer Joost P. A. , de Ridder Jan Willem , Perk Lars R. , Verdaasdonk Rudolf M.
Published: January 2013

Purpose:

With the introduction of hybrid PET/MRI systems, it has become more likely that the cyclotron and MRI systems will be located close to each other. This study considered the interference between a cyclotron and a superconducting MRI system.

Methods:

Interactions between cyclotrons and MRIs are theoretically considered. The main interference is expected to be the perturbation of the magnetic field in the MRI due to switching on or off the magnetic field of the cyclotron. MR imaging is distorted by a dynamic spatial gradient of an external inplane magnetic field larger than 0.5–0.04μT/m, depending on the specific MR application. From the design of a cyclotron, it is expected that the magnetic fringe field at large distances behaves as a magnetic dipolar field. This allows estimation of the full dipolar field and its spatial gradients from a single measurement. Around an 18 MeV cyclotron (Cyclone, IBA), magnetic field measurements were performed on 5 locations and compared with calculations based upon a dipolar field model.

Results:

At the measurement locations the estimated and measured values of the magnetic field component and its spatial gradients of the inplane component were compared, and found to agree within a factor 1.1 for the magnetic field and within a factor of 1.5 for the spatial gradients of the field. In the specific case of the 18 MeV cyclotron with a vertical magnetic field and a 3T superconducting whole body MR system, a minimum distance of 20 m has to be considered to prevent interference.

Conclusions:

This study showed that a dipole model is sufficiently accurate to predict the interference of a cyclotron on a MRI scanner, for site planning purposes. The cyclotron and a whole body MRI system considered in this study need to be placed more than 20 m apart, or magnetic shielding should be utilized.