IIUM Engineering Journal
Not a member yet
783 research outputs found
Sort by
ENHANCEMENT OF STABILITY ON AUTONOMOUS WAYPOINT MISSION OF QUADROTOR USING LQR INTEGRATOR CONTROL
Get PDFThe ability of the quadrotor in the waypoint trajectory tracking becomes an essential requirement in the completion of various missions nowadays. However, the magnitude of steady-state errors and multiple overshoots due to environmental disturbances leads to motion instability. These conditions make the quadrotor experience a shift and even change direction from the reference path. As a result, to minimize steady-state error and multiple overshoots, this study employs a Linear Quadratic Regulator control method with the addition of an Integrator. Comparisons between LQR without Integrator and LQR with Integrator were performed. They were implemented on a quadrotor controller to track square and zig-zag waypoint patterns. From experimental results, LQR without Integrator produce of 2 meters steady-state error and -1.04 meters undershoot average with an accuracy of 64.84 % for square pattern, along 3.19 meters steady-state error, and -1.12 meters undershoot average with an accuracy of 46.73 % for a zig-zag way. The LQR method with integrator produce of 1.06 meters steady-state error with accuracy 94.96 % without multiple-overshoot for square pattern, the 1.06 meters steady-state error, and -0.18 meters undershoot average with an accuracy of 86.49 % for the zig-zag way. The results show that the LQR control method with Integrator can minimize and improve steady-state error and multiple overshoots in quadrotor flight. The condition makes the quadrotor able to flying path waypoints with the correct system specification.
ABSTRAK: Kemampuan quadrotor dalam pengesanan lintasan waypoint menjadi syarat penting dalam menyelesaikan pelbagai misi pada masa kini. Walau bagaimanapun, besarnya ralat keadaan mantap dan banyak kelebihan kerana gangguan persekitaran menyebabkan ketidakstabilan pergerakan. Keadaan ini menjadikan quadrotor mengalami pergeseran dan bahkan mengubah arah dari jalur rujukan. Oleh itu, kajian ini menggunakan kaedah kawalan Linear Quadratic Regulator dengan penambahan integrator dalam meminimumkan ralat keadaan mantap dan banyak kelebihan. Perbandingan antara LQR tanpa Integrator dan LQR dengan Integrator dilakukan. Mereka dilaksanakan pada pengawal quadrotor untuk mengesan corak titik jalan persegi dan zig-zag. Dari hasil eksperimen, LQR tanpa Integrator menghasilkan ralat keadaan mantap 2 meter dan -1.04 meter rata-rata undur tembak dengan ketepatan 64.84% untuk corak persegi, sepanjang ralat keadaan tetap 3.19 meter, dan -1.12 meter rata-rata undur bawah dengan ketepatan 46.73 % untuk cara zig-zag. Kaedah LQR dengan integrator menghasilkan ralat keadaan mantap 1.06 meter dengan ketepatan 94.96% tanpa tembakan berlebihan untuk corak segi empat sama, ralat keadaan mantap 1.06 meter, dan rata-rata undur tembak -0.18 meter dengan ketepatan 86.49% untuk zig-zag cara. Hasilnya menunjukkan bahawa kaedah kawalan LQR dengan Integrator dapat meminimumkan dan memperbaiki ralat keadaan mantap dan banyak overhoot dalam penerbangan quadrotor. Keadaan tersebut menjadikan quadrotor dapat terbang ke titik jalan dengan spesifikasi sistem yang betul
Editorial
Get PDFCHIEF EDITOR
Ahmad Faris Ismail, IIUM, Malaysia
TECHNICAL EDITOR
Sany Izan Ihsan, IIUM, Malaysia
EXECUTIVE EDITOR
AHM Zahirul Alam, IIUM, Malaysia
ASSOCIATE EDITOR
Nor Farahidah Za’bah, IIUM, Malaysia
LANGUAGE EDITOR
Lynn Mason, Malaysia
COPY EDITOR
Hamzah Mohd. Salleh, IIUM, Malaysia
MALAY TRANSLATOR
Nurul Arfah Che Mustapha, IIUM, Malaysia
EDITORIAL BOARD MEMBERS
Abdullah Al-Mamun, IIUM, Malaysia
Abdumalik Rakhimov, IIUM, Malaysia
Ali Sophian, IIUM, Malaysia
Erwin Sulaeman, IIUM, Malaysia
Hanafy Omar, Saudi Arabia
Hazleen Anuar, IIUM, Malaysia
Konstantin Khanin, University of Toronto, Canada
Ma'an Al-Khatib, IIUM, Malaysia
Md Zahangir Alam, IIUM, Malaysia
Meftah Hrairi, IIUM, Malaysia
Mohamed B. Trabia, United States
Mohammad S. Alam, Texas A&M University-Kingsville, United States
Mustafizur Rahman, National University Singapore, Singapore
Ossama Abdulkhalik, Michigan Technological University, United States
Othman O Khalifa, IIUM, Malaysia
Razi Nalim, IUPUI, Indianapolis, Indiana, United States
Rosminazuin AB. Rahim, IIUM, Malaysia
Sharifah Imihezri Syed Shaharuddin, IIUM, Malaysia
Waqar Asrar, IIUM, Malaysia
INTERNATIONAL ADVISORY COMMITTEE
Anwar, United States
Abdul Latif Bin Ahmad, Malaysia
Farzad Ismail, USM, Pulau Pinang, Malaysia
Hanafy Omar, Saudi Arabia
Hany Ammar, United States
Idris Mohammed Bugaje, Nigeria
K.B. Ramachandran, India
Kunzu Abdella, Canada
Luis Le Moyne, ISAT, University of Burgundy, France
M Mujtaba, United Kingdom
Mohamed AI-Rubei, Ireland
Mohamed B Trabia, United States
Syed Kamrul Islam, United States
Tibor Czigany, Budapest University of Technology and Economics, Hungary
Yiu-Wing Mai, The University of Sydney, Australia.
AIMS & SCOPE OF IIUM ENGINEERING JOURNAL
The IIUM Engineering Journal, published biannually (January and July), is a carefully refereed international publication of International Islamic University Malaysia (IIUM). Contributions of high technical merit within the span of engineering disciplines; covering the main areas of engineering: Electrical and Computer Engineering; Mechanical and Manufacturing Engineering; Automation and Mechatronics Engineering; Material and Chemical Engineering; Environmental and Civil Engineering; Biotechnology and Bioengineering; Engineering Mathematics and Physics; and Computer Science and Information Technology are considered for publication in this journal. Contributions from other areas of Engineering and Applied Science are also welcomed. The IIUM Engineering Journal publishes contributions under Regular papers and Invited review papers. It also welcomes contributions that address solutions to the specific challenges of the developing world, and address science and technology issues from an Islamic and multidisciplinary perspective.
REFEREES’ NETWORK
All papers submitted to IIUM Engineering Journal will be subjected to a rigorous reviewing process through a worldwide network of specialized and competent referees. Each accepted paper should have at least two positive referees’ assessments.
SUBMISSION OF A MANUSCRIPT
A manuscript should be submitted online to the IIUM-Engineering Journal website at
http://journals.iium.edu.my/ejournal. Further correspondence on the status of the paper could be done through the journal website.
Whilst every effort is made by the publisher and editorial board to see that no inaccurate or misleading data, opinion or statement appears in this Journal, they wish to make it clear that the data and opinions appearing in the articles and advertisement herein are the responsibility of the contributor or advertiser concerned. Accordingly, the publisher and the editorial committee accept no liability whatsoever for the consequence of any such inaccurate or misleading data, opinion or statement.
IIUM Engineering Journal
ISSN: 1511-788X E-ISSN: 2289-7860
Published by: IIUM Press, International Islamic University Malaysia Jalan Gombak, 53100 Kuala Lumpur, Malaysia Phone (+603) 6421-5014, Fax: (+603) 6421-629
CYTOTOXICITY EFFECT OF IONIC LIQUID-GRAVIOLA FRUIT (ANNONA MURICATA) EXTRACT TO HUMAN COLON CANCER (HT29) CELL LINES
Get PDFThe present study aimed to investigate the anti-proliferative effect of the ionic liquid-Graviola fruit (IL-GFE) extract on colon adenocarcinoma (HT29) cell lines and their kinetics behaviour to assess the Graviola fruit potential as a therapeutic alternative in cancer treatment. The phytoconstituents content of IL-GFE was identified using GC-TOFMS apparatus and measured its cytotoxicity on HT29 by tetrazolium bromide. Then the cytokinetic behaviour of the treated HT29 cells with IL-GFE was illustrated using the cells' growth curve. Besides, the cell cycle phase perturbation for the treated HT29 was applied using a flow cytometry technique. Qualitative identification of phytoconstituents of IL-GFE showed that Graviola fruit contains acetogenins, alkaloids, flavonoids, tannins and saponins compounds. IL-GF extract displayed a cytotoxicity effect on HT29 cells with the IC50 value of 10.56 µg/mL, while Taxol showed an IC50 value of 1.22 µg/mL. IL-GFE also decreased the cell generation number from 3.93 to 2.96 generations compared to Taxol-treated cells 2.01 generations. The microscope observation of the HT29 cells treated with the crude IL-GFE displayed loss of density and cell detachment. The extract's growth inhibition was related to the cell cycle arrest at the G0/G1 phase. IL-GFE inhibited colon adenocarcinoma HT29 cells' proliferation and affected their kinetic behaviour by lowering cell viability, inducing apoptosis, and arresting the cell cycle at the G0/G1 phase.
ABSTRAK: Kajian ini bertujuan untuk mengkaji kesan anti-proliferatif ekstrak buah-ion Graviola (IL-GFE) pada garis sel adenokarsinoma kolon (HT29) dan tingkah laku kinetik mereka untuk menilai potensi buah Graviola sebagai alternatif terapi untuk barah rawatan. Kandungan fitokonstituen IL-GFE dikenal pasti menggunakan alat GC-TOFMS dan mengukur sitotoksisitasnya pada HT29 oleh tetrazolium bromida. Kemudian tingkah laku sitokinetik sel HT29 yang dirawat dengan IL-GFE digambarkan menggunakan keluk pertumbuhan sel. Selain itu, gangguan fasa kitaran sel untuk HT29 yang dirawat diaplikasikan menggunakan teknik sitometri aliran. Pengenalpastian kualitatif fitokonstituen IL-GFE menunjukkan bahawa buah Graviola mengandungi asetogenin, alkaloid, flavonoid, tanin dan sebatian saponin. Ekstrak IL-GF memperlihatkan kesan sitotoksisiti pada sel HT29 dengan nilai IC50 10.56 µg/mL, sementara Taxol menunjukkan nilai IC50 1.22 µg/mL. IL-GFE juga menurunkan jumlah penjanaan sel dari 3.93 hingga 2.96 generasi berbanding sel yang dirawat Taxol 2.01 generasi. Pemerhatian mikroskop sel HT29 yang dirawat dengan IL-GFE kasar menunjukkan kehilangan ketumpatan dan detasmen sel. Perencatan pertumbuhan ekstrak berkaitan dengan penangkapan kitaran sel pada fasa G0/G1. IL-GFE menghalang percambahan sel HT29 adenokarsinoma kolon dan mempengaruhi tingkah laku kinetik mereka dengan menurunkan daya maju sel, mendorong apoptosis, dan menghentikan kitaran sel pada fasa G0/G1
MULTI-OBJECTIVE OPTIMIZATION OF SNAKE ROBOT IN SERPENTINE LOCOMOTION
Get PDFThis paper presents multi-objective optimization for a snake robot with serpentine locomotion. Genetic algorithm (GA) is used to achieve two objectives: minimizing the total travelling time and minimizing the total energy consumption. The effect of initial values of winding angle and acceleration on energy consumption and average speed is depicted. The simulation results show a periodic pattern of the joint torques when the robot maintains a serpenoid curve during travel. Moreover, a Pareto-optimal front was generated for optimal solutions of both of the objectives, while the weighted sum method was used for selecting the best solution. Finally, the simulation results were verified experimentally on an eight-link snake robot considering the limitations of the servomotors used in the experiment. The experimental results with the winding angle of 30° was found as the optimum winding angle that can achieve both objectives of minimizing the energy consumption and the travelling time.
ABSTRAK: Kajian ini berkenaan pelbagai-objektif optimum bagi robot ular dengan gerakan serpentin. Algoritma genetik (GA) diguna bagi mencapai dua objektif ini iaitu mengurangkan jumlah masa gerakan dan guna tenaga. Gambaran kesan awal nilai sudut belitan dan pecutan pada guna tenaga dan purata kelajuan dihasilkan. Dapatan simulasi menunjukkan corak berkala tork sendi yang tetap terhasil semasa robot ini berkeadaan lengkung serpenoid ketika bergerak. Tambahan, Pareto-optimal berdepan terhasil bagi solusi optimum pada kedua-dua objektif, sementara kaedah berat campuran digunakan bagi menentukan solusi terbaik. Akhirnya, dapatan simulasi disahkan secara eksperimen pada robot ular lapan-bahagian dengan menimbangkan kekurangan servomotor yang digunakan dalam eksperimen. Dapatan eksperimen menunjukkan sudut belitan 30° adalah sudut belitan optimum bagi kedua-dua objektif iaitu mengurangkan tenaga dan masa gerakan
CLASSIFICATION OF CHEST RADIOGRAPHS USING NOVEL ANOMALOUS SALIENCY MAP AND DEEP CONVOLUTIONAL NEURAL NETWORK
Get PDFThe rapid advancement in pattern recognition via the deep learning method has made it possible to develop an autonomous medical image classification system. This system has proven robust and accurate in classifying most pathological features found in a medical image, such as airspace opacity, mass, and broken bone. Conventionally, this system takes routine medical images with minimum pre-processing as the model's input; in this research, we investigate if saliency maps can be an alternative model input. Recent research has shown that saliency maps' application increases deep learning model performance in image classification, object localization, and segmentation. However, conventional bottom-up saliency map algorithms regularly failed to localize salient or pathological anomalies in medical images. This failure is because most medical images are homogenous, lacking color, and contrast variant. Therefore, we also introduce the Xenafas algorithm in this paper. The algorithm creates a new kind of anomalous saliency map called the Intensity Probability Mapping and Weighted Intensity Probability Mapping. We tested the proposed saliency maps on five deep learning models based on common convolutional neural network architecture. The result of this experiment showed that using the proposed saliency map over regular radiograph chest images increases the sensitivity of most models in identifying images with air space opacities. Using the Grad-CAM algorithm, we showed how the proposed saliency map shifted the model attention to the relevant region in chest radiograph images. While in the qualitative study, it was found that the proposed saliency map regularly highlights anomalous features, including foreign objects and cardiomegaly. However, it is inconsistent in highlighting masses and nodules.
ABSTRAK: Perkembangan pesat sistem pengecaman corak menggunakan kaedah pembelajaran mendalam membolehkan penghasilan sistem klasifikasi gambar perubatan secara automatik. Sistem ini berupaya menilai secara tepat jika terdapat tanda-tanda patologi di dalam gambar perubatan seperti kelegapan ruang udara, jisim dan tulang patah. Kebiasaannya, sistem ini akan mengambil gambar perubatan dengan pra-pemprosesan minimum sebagai input. Kajian ini adalah tentang potensi peta salien dapat dijadikan sebagai model input alternatif. Ini kerana kajian terkini telah menunjukkan penggunaan peta salien dapat meningkatkan prestasi model pembelajaran mendalam dalam pengklasifikasian gambar, pengesanan objek, dan segmentasi gambar. Walau bagaimanapun, sistem konvensional algoritma peta salien jenis bawah-ke-atas kebiasaannya gagal mengesan salien atau anomali patologi dalam gambar-gambar perubatan. Kegagalan ini disebabkan oleh sifat gambar perubatan yang homogen, kurang variasi warna dan kontras. Oleh itu, kajian ini memperkenalkan algoritma Xenafas yang menghasilkan dua jenis pemetaan saliensi anomali iaitu Pemetaan Kebarangkalian Keamatan dan Pemetaan Kebarangkalian Keamatan Pemberat. Kajian dibuat pada peta salien yang dicadangkan iaitu pada lima model pembelajaran mendalam berdasarkan seni bina rangkaian neural konvolusi yang sama. Dapatan kajian menunjukkan dengan menggunakan peta salien atas gambar-gambar radiografi dada tetap membantu kesensitifan kebanyakan model dalam mengidentifikasi gambar-gambar dengan kelegapan ruang udara. Dengan menggunakan algoritma Grad-CAM, peta salien yang dicadangkan ini mampu mengalih fokus model kepada kawasan yang relevan kepada gambar radiografi dada. Sementara itu, kajian kualitatif ini juga menunjukkan algoritma yang dicadangkan mampu memberi ciri anomali, termasuk objek asing dan kardiomegali. Walau bagaimanapun, ianya tidak konsisten dalam menjelaskan berat dan nodul
WSN-BASED MONITORING SYSTEMS FOR THE SOLAR POWER STATIONS OF THE TELECOMMUNICATION DEVICES
Get PDFRenewable energy sources are an increasingly popular way to generate electrical energy for telecommunications systems. The use and effectiveness of remote monitoring systems in such systems has led to growing interests relatively to it. As with any new technological systems, new problems have arisen in the use of renewable energy sources in telecommunications systems and the use of IoT-based remote monitoring systems in them. In particular, one of these problems is the decentralization of remote monitoring systems for renewable power plants of telecommunication systems. The paper details the stages of development and modelling of open-source centralized monitoring systems for solar power station of telecommunication systems. In this paper, a real-time remote monitoring system of solar power sources was modelled and investigated by wireless sensor networks of telecommunications devices. Proteus software environment was obtained for modelling. Before modelling the system, a system structure and a block diagram were developed, each of the elements that are part of the system is described. Software for the system was created. The developed structure and software were tested by modelling. The results of the modelling were presented in a virtual terminal, an oscillography, and a local web browser.
ABSTRAK: Sumber tenaga boleh baharu semakin meningkat popular dalam menghasilkan tenaga elektrik bagi sistem telekomunikasi. Penggunaan dan keberkesanan sistem pemonitoran jarak jauh dalam jaringan ini telah membawa kepada peningkatan minat kepada tenaga boleh baharu. Walau bagaimanapun, melalui sistem teknologi baru ini, masalah baru timbul dalam penggunaan punca tenaga boleh baharu dalam sistem telekomunikasi dan penggunaan bersama sistem pemonitoran berdasarkan IoT. Khususnya dalam desentralisasi sistem pemonitoran jarak jauh bagi loji kuasa sistem telekomunikasi. Kajian ini merincikan peringkat pembinaan dan model sumber terbuka berpusat sistem pemonitoran bagi sistem janakuasa solar sistem telekomunikasi. Kajian ini turut memodelkan sistem pemonitoran jarak jauh secara langsung bagi sumber kuasa solar dan dikaji dengan rangkaian sensor tanpa jaringan bagi alatan telekomunikasi. Perisian Proteus telah dihasilkan bagi model ini. Sebelum model sistem dibina, struktur sistem dan gambar rajah blok dibina. Setiap unsur dalam sistem ini diperihalkan. Perisian bagi sistem ini turut dibina. Struktur yang dibina dan perisian ini diuji melalui model. Hasil dapatan model dibentangkan dalam pangkalan maya, oscilograf dan pelayar web tempatan
THE EFFECT OF LATERAL LIFTING TASKS ON HAND GRIP AND PINCH STRENGTH MEASUREMENTS
Get PDFIn lateral material handling tasks, which is very common in industries, warehouse systems, and other sectors, the workers can lead to work-related musculoskeletal disorders (WMSDs) because of the task and work designs, especially in upper extremities. WMSDs in hand, wrist, and fingers cause workers to have health problems, in pain and uncomfortable, hence decrease their working productivity and efficiency. The workstations distances are one of the factors that might affect workers when they perform manual material handling laterally, which can lead to WMSDs in hands. Hence, there is a need to study the relationship between transfer distances with the hand grip and pinch strengths. An experiment was carried out with 30 male participants to identify the relationship of lateral transfer distances with the hand grip and pinch strengths. The results obtained from the experiment were further investigated and analysed by using repeated measure one-way MANOVA and graphs. The results had proved that in the distances of 1.0 m, 1.25 m and 1.5 m did not affect one’s hand grip and pinch strengths. But, the postures and movements were varied based on distances.
ABSTRAK: Pengangkutan barang atau bahan secara lateral amat biasa dalam industri, gudang dan sektor-sektor lain, dan kerja ini akan menyebabkan pekerja menghadapi penyakit gangguan muskuloskeletal berkaitan kerja (WMSDs) terutamanya di bahagian tangan. WMSDs yang melibatkan tangan dan jari menyebabkan pekerja mempunyai masalah kesihatan secara kekal dan mengalami kesakitan serta tidak-keselesaan. Secara tidak langsung, masalah ini telah mengurangkan prestasi mereka ketika bekerja. Syarikat terpaksa memberi bayaran yang tinggi kepada pekerja untuk kos perubatan and mengalami kerugian besar kerana pekerja yang tidak datang bekerja disebabkan penyakit tersebut. Jarak antara dua stesen kerja adalah faktor yang menyebabkan penyakit ini dihadapi oleh pekerja. Oleh itu, kajian diperlukan untuk mengkaji hubungan antara jarak dan kekuatan genggaman tangan serta jari. Satu esperimen yang melibatkan 30 orang lelaki responden telah dijalankan untuk mengenal pasti hubungan antara jarak dan ganggaman tangan serta jari. Hasil daripada esperimen telah dikaji dan dianalisiskan dengan menggunakan MANOVA dan grafs. Hasil kajian telah membuktikan bahawa jarak dalam 1.0m, 1.25m dan 1.5m tidak membawa apa-apa kesan terhadap genggaman tangan dan jari. Cara dan pergerakan responden adalah berbeza dan disebabkan oleh jarak, walaubagaimanapun, cara dan pergerakan responden tidak membawa sebarang kesan terhadap kekuatan genggaman tangan dan jari mereka
AN AN INVESTIGATION OF THE SENSITIVITY OF POLYMER-COATED SURFACE ACOUSTIC WAVE-BASED GAS SENSORS IN THE DETECTION OF VOLATILE ORGANIC COMPOUNDS
No full textSurface acoustic wave sensors (SAWs) are excellent at detecting volatile organic compounds (VOCs) since a sensing layer can be created by spreading a thin film of material across the delay line. This critically enhances performance as it is sensitive to the physical phenomena of interest. This study aims to provide a thorough investigation of the sensitivity of polymer-coated SAW-based gas sensors to VOCs using simulations via the finite element method (FEM). As such, quartz was chosen as the piezoelectric substrate while polymeric materials were chosen as the sensing layers due to their high sensitivity, low energy consumption, short response time, performance at room temperature, and reversibility after exposure to an analyte. The polymeric materials chosen were: (1) polyisobutylene (PIB), (2) polydimethylsiloxane (PDMS), (3) polyisoprene (PIP), (4) polyimide (PI), and (5) phenylmethyldiphenylsilicone (OV25). The VOCs chosen for investigation were: (1) dichloromethane (DCM), (2) trichloroethylene (TCE), (3) 1,2-dichloroethylene (DCE), and (4) carbon tetrachloride (CCl4). The performance of each polymer-coated SAW sensor was evaluated in terms of frequency shift and sensitivity to each VOC in FEM simulations. Our study found that the PIB-coated sensor had the highest sensitivity (4.0571 kHz/ppm) to DCM vapor and good sensitivity (45.257 kHz/ppm) to TCE vapor. However, the performance of each polymer-coated sensor varied depending on the type of VOC being tested. As an example, while the OV25-coated sensor was more sensitive (52.57 kHz/ppm) than the PIB-coated sensor (53.54 kHz/ppm) to TCE vapor regardless of the concentration, the PIB-coated sensor was more sensitive to DCM vapor at both low (4.06 kHz/ppm) and high (3.54 kHz/ppm) concentrations than the OV25-coated sensor. Therefore, the results of our FEM simulations indicate that polymer-coated SAW-based gas sensors are highly capable of self-powered VOC detection.
ABSTRAK: Sensor gelombang akustik permukaan (SAW) adalah sangat baik dalam mengesan sebatian organik meruap yang tidak stabil (VOCs), kerana lapisan pengesan dapat dihasilkan dengan melapis nipis bahan pada lapisan garis tunda. Cara ini dapat menambah baik prestasi kerana ianya sensitif kepada fenomena fizikal yang dituju. Kajian ini bertujuan bagi menyediakan kajian menyeluruh terhadap kesensitifan sensor gas berasaskan SAW bersalut polimer pada VOC menggunakan simulasi melalui kaedah unsur terhingga (FEM). Oleh itu, kuarza dipilih sebagai substrat piezoelektrik manakala bahan polimer dipilih sebagai lapisan penginderaan berdasarkan kepekaan tinggi, penggunaan tenaga rendah, respon masa singkat, prestasi suhu bilik, dan faktor keboleh-balikan setelah terdedah kepada analit. Bahan polimer yang dipilih adalah: (1) polisobutilena (PIB), (2) polidimethilsiloxana (PDMS), (3) polisoprena (PIP), (4) polimida (PI), dan (5) phenilmethildiphenilsilikon (OV25). VOC terpilih bagi kajian adalah: (1) diklorometana (DCM), (2) trikloretilena (TCE), (3) 1,2-dikloroetilena (DCE), dan (4) karbon tetraklorida (CCl4). Prestasi setiap sensor SAW bersalut polimer dinilai berdasarkan peralihan frekuensi dan kesensitifan pada setiap VOC simulasi FEM. Dapatan kajian menunjukkan sensor bersalut-PIB mempunyai kesensitifan paling tinggi (4.0571 kHz/ppm) terhadap wap DCM dan kepekaan yang baik (45.257 kHz / ppm) terhadap wap TCE. Walau bagaimanapun, prestasi setiap sensor bersalut polimer adalah berbeza bergantung kepada jenis VOC yang sedang diuji. Sebagai contoh, sensor bersalut OV25 adalah lebih sensitif (52,57 kHz/ppm) daripada sensor bersalut PIB (53,54 kHz/ppm) pada wap TCE tanpa mengira kepekatan. Manakala sensor bersalut PIB lebih sensitif terhadap wap DCM pada kedua-dua kepekatan rendah (4.06 kHz/ppm) dan tinggi (3.54 kHz/ppm) daripada sensor bersalut-OV25. Oleh itu, hasil simulasi FEM menunjukkan bahawa sensor gas berasaskan SAW bersalut polimer adalah sangat berpotensi sebagai pengesan VOC berkuasa sendiri
ONLINE NEWS CLASSIFICATION USING MACHINE LEARNING TECHNIQUES
Get PDFA massive rise in web-based online content today pushes businesses to implement new approaches and resources that might support better navigation, processing, and handling of high-dimensional data. Over the Internet, 90% of the data is unstructured, and there are several approaches through which this data can translate into useful, structured data—classification is one such approach. Classification of knowledge into a good collection of groups is significant and necessary. As the number of machine-readable documents proliferates, automatic text classification is badly needed to classify these documents. Unlabeled documents are categorized into predefined classes of labeled documents using text labeling, a supervised learning technique. This paper reviewed some existing approaches for classifying online news articles and discusses a framework for the automatic classification of online news articles. For achieving high accuracy, different classifiers were tried. Our experimental method achieved 93% accuracy using a Bayesian classifier and present in terms of confusion metrics.
ABSTRAK: Peningkatan tinggi pada masa kini pada maklumat dalam talian berasaskan web menyebabkan kaedah baru dalam bisnes telah diguna pakai dan sumber sokongan seperti navigasi, proses, dan pengurusan data berdimensi-tinggi adalah perlu. 90% data di internet adalah data tidak berstruktur, dan terdapat pelbagai kaedah data ini dapat diterjemahkan kepada data berguna, lebih berstruktur — iaitu melalui kaedah klasifikasi. Klasifikasi ilmu kepada koleksi kumpulan baik adalah penting dan perlu. Seperti mana mesin-boleh baca dokumen berkembang pesat, teks klasifikasi automatik juga sangat diperlukan bagi mengklasifikasi dokumen-dokumen ini. Dokumen yang tidak dilabel dikategori sebagai pengelasan pratakrif dokumen berlabel melalui teks label, iaitu teknik pembelajaran berpenyelia. Kajian ini mengkaji semula pendekatan sedia ada bagi artikel berita dalam talian dan membincangkan rangka kerja bagi pengelasan automatik artikel berita dalam talian. Bagi menghasilkan ketepatan yang tinggi, kami menggunakan pelbagai alat klasifikasi. Kaedah eksperimen ini mempunyai ketepatan 93% menggunakan pengelas Bayesian dan data dibentangkan berdasarkan matriks kekeliruan
ACOUSTIC WAVE PROPAGATION IN HIGH SCALE IMPEDANCE MISMATCH MEDIUMS
Get PDFA finite element analysis of acoustic propagation in a multilayered medium is presented in this paper. A circular transmitter (diameter 14 mm, thickness 3 mm) and a rectangular receiver (20×10×0.5 mm3) are set to detect the variations in the propagation pattern. A complex medium (70×40×60 mm3) composed of skin, fat, muscle, bone and liquid is designed in a simulated environment. A scale of frequencies (10 kHz to 2 MHz) is applied to trace the impact on the propagation pattern as well. It is found from the analysis that fat and liquid layers affect the acoustic propagation the most (-69 dB), which results in a significant drop in the received sound pressure level at the receiving end. Again, other than skin and fat layers, low frequencies (less than 1 MHz) are more beneficial in terms of sound pressure level. However, higher frequencies contribute to lower displacements at the receiving end, which will cause less power potential as well.
ABSTRAK: Analisis elemen terhingga bagi penyebaran akustik dalam medium berlapis dibentangkan dalam kajian ini. Pemancar bulat (diameter 14 mm, ketebalan 3 mm) dan penerima segi empat tepat (20 × 10 × 0.5 mm3) diatur bagi mengesan perubahan pola penyebaran. Medium kompleks (70 × 40 × 60 mm3) yang terdiri daripada kulit, lemak, otot, tulang dan cecair direka dalam persekitaran simulasi. Skala frekuensi (10 kHz hingga 2 MHz) digunakan bagi mengesan corak penyebaran. Dapatan kajian menunjukkan bahawa lapisan lemak dan cecair mempengaruhi penyebaran akustik (-69 dB), yang mengakibatkan penurunan mendadak tahap penerimaan tekanan bunyi di hujung penerima. Selain lapisan kulit dan lemak, frekuensi rendah (kurang dari 1 MHz) adalah lebih berguna dari segi tahap tekanan suara. Walau bagaimanapun, frekuensi lebih tinggi menyebabkan kurang anjakan di hujung penerima, sekaligus mengurangkan potensi daya tenaga