IIUM Engineering Journal最新文献

{"title":"PLC-based PID controller for real-time pH neutralization process using Palm Oil Mill Effluent","authors":"Azavitra Zainal, Norhaliza Abdul Wahab, M. I. Yusof","doi":"10.31436/iiumej.v24i1.2366","DOIUrl":"https://doi.org/10.31436/iiumej.v24i1.2366","url":null,"abstract":"The pH neutralization process is a highly non-linear process and time delay system that is difficult to control and to accurately model mathematically. Therefore, the empirical method, which needs reliable experimental data to represent the process dynamics, is often used. In this paper, the performance of the PLC-based PID controller was studied using a different adjustment of the acid dosing pump stroke rate in the pH neutralization process. The pH neutralization process is a single-input, single-output system where the manipulated variable is the alkali dosing pump stroke rate, the controlled variable is pH, and the acid dosing pump stroke rate is set as a constant. The acid dosing pump stroke rate was adjusted to 10%, 15% and 25%. The results showed that the best performance of the PID controller was based on setpoint tracking when the setting of the acid dosing pump stroke rate was set at 10%, which could be used as experimental data in the empirical method. In addition, the real-time control system was integrated between PLC and MATLAB using National Instruments OPC server to access the experimental data in real-time, conduct simulation, and to develop the advanced control in the future.\u0000ABSTRAK: Peneutralan pH adalah proses tidak linear yang sukar dikawal dan sukar mendapat model matematik yang tepat. Oleh itu, kaedah empirikal memerlukan data eksperimen masa nyata bagi mewakili proses dinamik untuk mengatasi masalah ini. Kajian ini adalah berkaitan kajian prestasi pengawal PLC-berdasarkan PID menggunakan pelbagai perubahan kadar strok pam dos asid dalam proses peneutralan pH. Proses peneutralan pH ini adalah sistem satu input/output, di mana pemboleh ubah yang dimanipulasi adalah kadar peratusan strok pam dos alkali menggunakan pam peristaltik, pemboleh ubah kawalan ialah pH dan pemboleh ubah malar ialah peratusan dos asid.Kadar strok pam dos asid dilaraskan pada 10%, 15% dan 25%. Dapatan kajian menunjukkan prestasi terbaik kawalan PID adalah berdasarkan pengesan titik-set apabila kadar strok pam dos asid dilaraskan pada 10%, di mana ianya berkesan apabila digunakan sebagai data eksperimen dalam kaedah empirikal. Tambahan, kajian ini telah berjaya membentuk sistem kawalan masa nyata bagi proses penutralan pH menggunakan PLC dan MATLAB melalui pelayan National Instruments OPC bagi membolehkan pertukaran data eksperimen secara masa nyata yang cekap, menjalankan simulasi dan pembangunan kawalan termaju pada masa hadapan.","PeriodicalId":13439,"journal":{"name":"IIUM Engineering Journal","volume":"81 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84195219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ricochet of Spinning Spheres Off Water","authors":"R. Kiter, Mazin Y. Abbood, Omar Hassoon","doi":"10.31436/iiumej.v24i1.2448","DOIUrl":"https://doi.org/10.31436/iiumej.v24i1.2448","url":null,"abstract":"Liquid impact and ricochet is still attracting researchers interested in the field of hydrodynamics and naval engineering. The ricochet from a water surface experienced by spinning spheres was examined both analytically and numerically. A theoretical analysis was made to quantify the enhancement attained by imparting backspin to the sphere. Numerical simulation of the process was conducted by implementing ABAQUS software. The mathematical analysis and the simulation were built on the assumption that the effects of cavitation, splash, and two phase flow are negligible compared to hydro-dynamical forces of lift and drag. It was proven that both mathematical analysis and simulation were capable of predicting the trajectory of a spinning sphere during its course of entry into the water. Aspects like the critical angle of ricochet and the maximum depth of immersion were extracted from these trajectories and compared with available data. It was found that the analytical and numerical results were generally validated with respect to each other as well as to existing findings. Aluminum () spinning spheres, of radius 10 mm and speed of 10 m/sec, were examined. It was found that a 300 rad/sec backspin improves the critical angle of ricochet from 10.43 to 12.5 deg and increases the maximum depth of immersion from 1.52 to 1.83.  \"Magnus Effect\" usually acting on a fully immersed spinning sphere, was described and relations estimating the hydrodynamic forces were deduced. ABSTRAK: Keadaan pertumbuhan bakteria penghasil enzim protease aktif-sejuk terasing daripada sampel Antartika disaring menggunakan satu-faktor-satu-masa (OFAT). Kemudian, enzim protease ini diekstrak pada lewat fasa logaritma untuk ujian enzimatik. Strain yang menunjukkan aktiviti enzim tertinggi telah dipilih bagi tujuan pengoptimuman melalui Kaedah Permukaan Tindak Balas (RSM). Parameter yang dikaji adalah pada suhu pengeraman (4 - 36 °C), media pH (4 – 10) dan kepekatan NaCl (0 - 8 %). Berdasarkan dapatan OFAT, kesemua lapan bakteria menunjukkan kadar pertumbuhan tertinggi pada 20 °C, pH 7 dan 4% NaCl (w/v). Hasil ujian enzimatik menunjukkan enzim protease mentah yang diekstrak daripada SC8 menunjukkan aktiviti yang jauh lebih tinggi (0.20 U dan 0.37 U) daripada kawalan positif (0.11 U dan 0.31 U) pada -20 °C dan 20 °C. RSM ini menunjukkan kadar optimum bagi pertumbuhan SC8 adalah pada 20.5 °C, pH 6.83 dan 2.05% NaCl (w/v) dengan dapatan kadar pertumbuhan bakteria pada 3.70 ± 0.06 x 106 sel/jam. Keadaan pertumbuhan optimum SC8 melalui kajian ini bermanfaat bagi menghasilkan produk protease aktif-sejuk secara besar-besaran pada masa hadapan.","PeriodicalId":13439,"journal":{"name":"IIUM Engineering Journal","volume":"162 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73915711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of the lignocellulolytic substrates and fermentation process parameters on myco-coagulant production for water treatment","authors":"Maroua Fellah, M. Alam, A. Al-Mamun, Nasserldeen AHMED KHABBASHI, N. S. Engliman, Sonia HADJ ARAB","doi":"10.31436/iiumej.v24i1.2400","DOIUrl":"https://doi.org/10.31436/iiumej.v24i1.2400","url":null,"abstract":"In the present research, a fungal strain was used to produce a myco-coagulant via solid-state bioconversion to reduce water turbidity. The production of myco-coagulant was achieved using several low-cost lignocellulolytic substrates, namely coco peat, sawdust, palm kernel cake, and rice bran as sources of carbon and nitrogen. This research involves the study of both the effect of lignocellulolytic substrates and the parameters involved in the fermentation process for myco-coagulant production. Coco peat was chosen as a suitable lignocellulolytic substrate to serve as a carbon source for producing myco-coagulant, potentially reducing the turbidity by 84.6% from the kaolin suspension. Sawdust, palm kernel cake, and rice bran showed 33.06%, 30.18, and 21.18 %, respectively. Furthermore, a statistical approach to the Plackett-Burman design was conducted to evaluate the significant parameters that affect the production of myco-coagulant. Eleven fermentation process parameters were selected: concentration of coco peat (2- 4 %), incubation time (5-9 days), temperature (25-35 °C), pH (5-9), glucose (0-2 %), malt extract (1-2 %), yeast extract (0-2%), wheat flour (0-2 %), ammonium sulfate (0-1 %), inoculum size (1-3 %) and potassium dihydrogen phosphate (0-0.5 %). The selected variables were assessed through statistical analysis (main effects) based on their significance. Based on the main effect of each variable on flocculation activity, three variables, namely glucose, malt extract, and pH influenced high levels. On the other hand, the remaining eight variables did not significantly affect the production of myco-coagulant. Furthermore, a deeper study was conducted to further optimize the three effective variables involved in the fermentation process to evaluate these factors' influence on flocculation activity.\u0000ABSTRAK: Penyelidikan ini adalah berkenaan strain fungus yang digunakan bagi menghasilkan miko-koagulan melalui penukaran-bio berkeadaan pepejal bagi mengurangkan kekeruhan air. Miko-koagulan dihasilkan dengan menggunakan beberapa substrat lignoselulolitik berkos rendah, iaitu habuk kelapa, habuk papan, hampas kelapa sawit, dan dedak padi sebagai sumber karbon dan nitrogen. Penyelidikan ini mengkaji kesan substrat lignoselulolitik dan faktor-faktor yang terlibat dalam proses fermentasi bagi menghasilkan miko-koagulan. Habuk kelapa dipilih sebagai substrat lignoselulolitik yang sesuai berfungsi sebagai sumber karbon dalam menghasilkan miko-koagulan, berpotensi mengurangkan kekeruhan sebanyak 84.6% daripada ampaian kaolin. Sebaliknya, habuk papan, hampas kelapa sawit, dan dedak padi menunjukkan 33.06%, 30.18, dan 21.18 %, masing-masing. Tambahan pula, pendekatan statistik ke atas reka bentuk Plackett-Burman telah dijalankan bagi menilai parameter penting yang mempengaruhi penghasilan miko-koagulan. Sebelas parameter proses penapaian telah dipilih: kepekatan habuk kelapa (2- 4 %), masa pengeraman (5-9 hari), suhu (25-35 C), pH (5-9), glukosa (0-2 %)","PeriodicalId":13439,"journal":{"name":"IIUM Engineering Journal","volume":"163 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75985911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Higher Derivative Block Method with Generalised Steplength for Solving First-Order Fuzzy Initial Value Problems","authors":"Kashif Hussain, O. Adeyeye, N. Ahmad","doi":"10.31436/iiumej.v24i1.2380","DOIUrl":"https://doi.org/10.31436/iiumej.v24i1.2380","url":null,"abstract":"Block methods have been adopted in studies for solving first and higher order differential equations due to its impressive accuracy property. Taking a step further to improve this accuracy, researchers have considered the inclusion of higher-derivative terms in the block method, although this has been limited to the presence of one higher-derivative term in previous studies. Hence, this article aims at better accuracy by introducing two higher-derivative terms in the block method. In addition, this article presents a scheme with generalised step length such that there is flexibility on the choice of step length when developing the block method. The generalised step length scheme is adopted to develop a three-step block method for solving first-order fuzzy initial value problems. Its properties to ensure convergence and to show the region of absolute stability is investigated, and problems relating to charging and discharging of capacitor are considered. The absolute error shows the impressive accuracy of the three-step block method including obtaining the same values as the exact solution. Therefore, in addition to the new generalised algorithm presented in this article, a new three-step method for solving linear and nonlinear first order fuzzy initial value problems is presented.\u0000ABSTRAK: Kaedah blok digunakan dalam banyak kajian untuk menyelesaikan persamaan pembezaan peringkat pertama dan peringkat tinggi kerana sifat ketepatannya yang baik. Bagi meningkatkan ketepatan ini, penyelidik telah mengambil kira dengan memasukkan terbitan peringkat tinggi dalam kaedah blok, walaupun ini terhad pada satu sebutan terbitan peringkat tinggi dalam kajian sebelum. Oleh itu, kajian ini bertujuan bagi mendapatkan ketepatan yang lebih baik dengan memperkenalkan dua sebutan terbitan peringkat tinggi dalam kaedah blok. Tambahan, kajian ini memperkenalkan skema dengan panjang-langkah kaki biasa supaya terdapat kebolehlenturan pada pilihan langkah semasa membangunkan kaedah blok. Skema ini diadaptasi bagi membangunkan kaedah blok tiga-langkah bagi menyelesai masalah nilai awal peringkat pertama secara rawak. Ciri-ciri terperinci dikaji bagi memastikan penumpuan lingkungan kestabilan mutlak, dan masalah berkaitan pengecasan dan nyahcas kapasitor juga turut diambil kira. Ralat mutlak menunjukkan ketepatan yang mengkagumkan pada kaedah blok tiga-langkah termasuk mendapatkan nilai yang sama seperti penyelesaian. Oleh itu, tambahan pada algoritma ini, kaedah tiga-langkah bagi menyelesaikan linear dan tidak linear pada masalah nilai awal peringat pertama secara rawak diperkenalkan.","PeriodicalId":13439,"journal":{"name":"IIUM Engineering Journal","volume":"3 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79594606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Repurposing A Sampling-Based Planner for A Six-Degree-Of-Freedom Manipulator to Avoid Unpredictable Obstacles","authors":"Hafiz Iman, Md. Raisuddin Khan","doi":"10.31436/iiumej.v24i1.2642","DOIUrl":"https://doi.org/10.31436/iiumej.v24i1.2642","url":null,"abstract":"This paper presents the use of a sampling-based planner as a reactive planning scheme to avoid obstacles between a robotic arm and a moving obstacle. Based on a planner benchmark on an obstacle-ridden environment,  a rapidly-exploring random tree (RRT) planner has been used to populate the trajectories of the task space and map them into a configuration space using a Newton-Raphson-based inverse kinematic solver. Two robot poses are defined in a cycle of back-and-forth motion; the initial and the goal poses. The robot repeatedly moves from the starting pose to the end pose via the midpoint pose. Each set of trajectories is unique. We define this unique solution within the context of the configuration space as a cycle space. We impose a periodically occurring synthetic obstacle that moves in and out of the robot arm workspace defined in a simulated environment. Within the robot's workspace, the obstacle moves and cuts through the cycle space to emulate a dynamic environment. We also ran a benchmark on the available sampling planner in the OMPL library for static obstacle avoidance. Our benchmark shows that the RRT has the lowest time planning time at 0.031 s compared with other sampling-based planners available in the OMPL library, RRT implicitly avoids singularities within the cycle space, and reactively attempts to avoid synthetic moving objects near the robot hardware. This research intends to further investigate on the use of RGB-D sensor and LiDAR to track moving obstacles while abiding by the task space commands described by the initial and goal poses.\u0000ABSTRAK: Kertas kerja ini membentangkan penggunaan perancang berasaskan persampelan sebagai skim perancangan reaktif untuk mengelakkan halangan antara lengan robot dan halangan yang bergerak. Berdasarkan penanda aras perancang pada persekitaran yang dipenuhi halangan, perancang pokok rawak (RRT) penerokaan pantas telah digunakan untuk mengisi trajektori ruang tugas dan memetakannya ke dalam ruang konfigurasi menggunakan penyelesai kinematik songsang berasaskan Newton-Raphson. Dua pose robot ditakrifkan dalam kitaran gerakan bolak-balik; pose awal dan matlamat. Robot berulang kali bergerak dari pose permulaan ke pose akhir melalui pose titik tengah. Setiap set trajektori adalah unik. Kami mentakrifkan penyelesaian unik ini dalam konteks ruang konfigurasi sebagai ruang kitaran. Kami mengenakan halangan sintetik yang berlaku secara berkala yang bergerak masuk dan keluar dari ruang kerja lengan robot yang ditakrifkan dalam persekitaran simulasi. Dalam ruang kerja robot, halangan bergerak dan memotong ruang kitaran untuk meniru persekitaran yang dinamik. Kami juga menjalankan penanda aras pada perancang pensampelan yang tersedia dalam perpustakaan OMPL untuk mengelakkan halangan statik. Penanda aras kami menunjukkan bahawa RRT mempunyai masa perancangan masa terendah pada 0.031 s berbanding dengan perancang berasaskan pensampelan lain yang terdapat dalam perpustakaan OMPL, RRT secara tersirat menge","PeriodicalId":13439,"journal":{"name":"IIUM Engineering Journal","volume":"80 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88163642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design of Miniaturized Antenna for IoT Applications Using Metamaterial","authors":"A. Jusoh, Nur Fatihah Husain, N. A. Abdul Malek, F. N. Mohd Isa, S. Mohamad","doi":"10.31436/iiumej.v24i1.2505","DOIUrl":"https://doi.org/10.31436/iiumej.v24i1.2505","url":null,"abstract":"With the accelerated development of wireless technology, miniaturized antennae have become outstandingly favored due to the growing demand of Internet of Things (IoT) devices that are essential to accommodate low power, high data rates, and long-range communication. When an antenna operates at lower frequencies, the size of the antenna becomes bulky, which has raised an issue in the integration of the antennae within IoT devices due to their size constraints. Hence, in this paper, a miniaturized ring-monopole antenna incorporated with Rectangular Complementary Split Ring Resonator (RCSRR) and slotted ground plane, was designed at 2.4 GHz and 5.8 GHz frequency bands. The antenna was miniaturized by 46.8 % with overall size of 30 mm x 24.8 mm x 1.6 mm, and it was printed on FR-4 substrate with dielectric constant of 4.3. Design optimization was carried out by modifying the antenna structure, optimizing the dimensions, and using a low loss Rogers RT5880 substrate with a dielectric constant of 2.2, and thickness of 1.575 mm. The width of the antenna was also reduced to 20 mm which furthered the size reduction to 57.8 %. From the simulation results, the antenna was operated at 2.448 GHz, 2.864 GHz, and 5.8 GHz frequency bands with good return loss at -13.872 dB, -33.491 dB, and -19.3 dB respectively. The antenna fabrication and measurement were also implemented to the best simulated design using different substrates to validate its performance by comparing the simulated results with the measured results.\u0000ABSTRAK: Dengan perkembangan pesat teknologi tanpa wayar, antena miniatur telah menjadi sangat digemari kerana permintaan yang semakin meningkat bagi peranti Internet Benda (IoT), iaitu mempunyai kuasa rendah, kadar data yang tinggi dan berkomunikasi jarak jauh. Apabila antena beroperasi pada frekuensi rendah, saiz antena menjadi besar, ini menimbulkan isu kekangan saiz pada antena ketika berada dalam peranti IoT. Oleh itu, kajian ini adalah berkenaan antena ekakutub-gelang kecil yang digabungkan dengan Resonator Gelang Pemisah Pelengkap Segiempat Tepat (RCSRR) dan satah tanah berslot, telah direka bentuk pada jalur frekuensi 2.4 GHz dan 5.8 GHz. Antena telah dikecilkan sebanyak 46.8 % dengan saiz keseluruhan 30 mm x 24.8 mm x 1.6 mm, dan ia dicetak pada substrat FR-4 dengan pemalar dielektrik 4.3. Reka bentuk optimum telah dilakukan dengan mengubah suai struktur antena, berdimensi optimum, menggunakan substrat Rogers RT5880 rendah kuasa dengan pemalar dielektrik 2.2, dan berketebalan 1.575 mm. Lebar antena juga dikurangkan sebanyak 20 mm, ini bermakna  pengurangan saiz berjaya ditingkatkan kepada 57.8%. Dapatan simulasi menunjukkan antena telah beroperasi pada jalur frekuensi 2.448 GHz, 2.864 GHz dan 5.8 GHz dengan pengurangan kehilangan pulangan kuasa yang baik iaitu pada -13.872 dB, -33.491 dB dan -19.3 dB masing-masing. Fabrikasi dan pengukuran antena juga telah dilaksanakan pada reka bentuk simulasi terbaik menggunakan substrat yang berbeza bagi ","PeriodicalId":13439,"journal":{"name":"IIUM Engineering Journal","volume":"88 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75008627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Control Strategy for Power Assist Upper Limb Rehabilitation Robot with the Therapist’s Motion Intention Prediction","authors":"Zulikha Ayomikun Adeola-Bello, N. Azlan, Salmah Anim ABU HASSAN","doi":"10.31436/iiumej.v24i1.2604","DOIUrl":"https://doi.org/10.31436/iiumej.v24i1.2604","url":null,"abstract":"Currently, fully automated rehabilitation robots can assist therapists in providing rehabilitation therapy, hence the patients could get hurt. On the other hand, manual treatment may cause less patient injury but it is tiresome, and there are not enough therapists in most countries. Power assist rehabilitation robots can support the therapists in conducting the treatment and may help to alleviate this problem. The goal of this study is to develop a control strategy for the robot to assist the therapist’s movement in a power assist upper limb rehabilitation treatment. The system combines the advantages of robotic and manual rehabilitation therapy. Torque and position sensors fitted on the power assist upper limb rehabilitation robot arm are used for motion intention estimation. The amount of angular velocity necessary to be delivered to the feedback controller will be determined by predicting the therapist‘s motion intention using the impedance control method. The resulting velocity from the motion intention estimator is incorporated into the Sliding Mode Control - Function Approximation Technique (SMC-FAT) based adaptive controller. The SMC-FAT based adaptive controller in the feedback loop, overcomes the uncertain parameters in the combination of the robot and the human arm. The motion intention estimator forecasts the movement of therapists. The proposed controller is used to regulate elbow flexion and extension motion on a power assist upper limb rehabilitation robot with one degree of freedom (DOF). The proposed control system has been tested using MATLAB simulation and hardware experimental tests. The outcomes demonstrate the effectiveness of the proposed controller in directing the rehabilitation robot to follow the desired trajectory based on the therapist's motion intention, with maximum errors of 0.002rad/sec, 0.005rad/sec and 0.02rad/sec for sinusoidal, constant torque values, and hardware experiment respectively.\u0000ABSTRAK: Pada masa ini, robot rehabilitasi automatik sepenuhnya dapat membantu ahli terapi dalam menyediakan terapi pemulihan, tetapi pesakit berkemungkinan tercedera. Sebaliknya, rawatan manual berkemungkinan mengurangkan kecederaan pesakit tetapi ia memenatkan, dan terdapat kurang ahli terapi yang mencukupi di kebanyakan negara. Robot pembantu rehabilitasi dapat membantu ahli terapi dalam menjalankan pemulihan dan mengurangkan masalah ini. Sistem ini menggabungkan kelebihan terapi pemulihan robotik dan manual. Alat pengesan tork dan kedudukan diletakkan pada anggota atas lengan robot rahabilitasi yang digunakan bagi mengesan anggaran jarak pergerakan ahli terapi. Anggaran halaju sudut diperlukan bagi kawalan gerak balas dan dapat diketahui melalui anggaran niat gerakan ahli terapi menggunakan kaedah kawalan impedans. Halaju yang terhasil daripada anggaran niat gerakan diadaptasi ke dalam pengawal adaptif berasaskan Kawalan Mod Gelongsor - Teknik Anggaran Fungsi (SMC-FAT). Pengawal penyesuaian berasaskan SMC-FAT dalam gelung ","PeriodicalId":13439,"journal":{"name":"IIUM Engineering Journal","volume":"22 3 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80048861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Optimization of Growth Condition of the Bacteria Producing Cold-Active Proteolytic Enzyme from the Antarctic Region","authors":"Muhammad Asyraf Abd Latip, N. Nordin, S. Alias, J. Smykla, F. Yusof, M. Mohamad","doi":"10.31436/iiumej.v24i1.2447","DOIUrl":"https://doi.org/10.31436/iiumej.v24i1.2447","url":null,"abstract":"The growth conditions of bacteria producing cold-active protease isolated from an Antarctic sample were screened using one-factor-at-time (OFAT). Then, crude protease of the strain was extracted during the late logarithmic phase for enzymatic assay. A strain that showed the highest enzyme activity was selected for optimization via response surface method (RSM). The parameters studied were incubation temperature (4 – 36 °C), pH media (4 – 10) and NaCl concentration (0 – 8%). Based on the OFAT results, all eight strains showed the highest growth rate at 20 °C, pH 7 and 4% (w/v) NaCl. The assay showed that the crude enzyme extracted from strain SC8 exhibited significantly higher activity (0.20 U and 0.37 U) than the positive control (0.11 U and 0.31 U) at -20 °C and 20 °C. RSM suggested that the optimized setting for growth of SC8 were at 20.5 °C, pH 6.83 and 2.05% (w/v) of NaCl with the results of the bacterial growth rate value was 3.70 ± 0.06 x 106 cells/hr. Optimal growth conditions of SC8 from this study are useful for the large-scale production of cold-active protease in future.\u0000ABSTRAK: Keadaan pertumbuhan bakteria yang menghasilkan enzim protease aktif sejuk daripada sampel Antartika disaring menggunakan satu faktor pada masa (OFAT). Kemudian, enzim protease ini diekstrak pada lewat fasa logaritma untuk ujian enzimatik. Strain yang menunjukkan aktiviti enzim tertinggi telah dipilih untuk tujuan pengoptimuman melalui kaedah permukaan tindak balas (RSM). Parameter yang dikaji ialah suhu pengeraman (4 – 36 °C), pH media (4 – 10) dan kepekatan NaCl (0 – 8%). Berdasarkan OFAT, kesemua lapan bakteria menunjukkan kadar pertumbuhan tertinggi pada 20 °C, pH 7 dan 4% NaCl. Hasil ujian enzimatik menunjukkan bahawa enzim protease yang diekstrak daripada SC8 mempamerkan aktiviti yang jauh lebih tinggi (0.20 U dan 0.37 U) daripada kawalan positif (0.11 U dan 0.31 U) pada -20 °C dan 20 °C. RSM mencadangkan tetapan optimum untuk pertumbuhan SC8 adalah pada 20.5 °C, pH 6.83 dan 2.05% NaCl dengan keputusan kadar pertumbuhan bakteria ialah 3.70 ± 0.06 x 106 sel/jam. Keadaan pertumbuhan optimum SC8 daripada kajian ini bermanfaat untuk menghasilkan produk protease aktif sejuk secara besar-besaran pada masa hadapan.\u0000The growth conditions of bacteria producing cold-active protease isolated from an Antarctic sample were screened using one-factor-at-time (OFAT). Then, crude protease of the strain was extracted during the late logarithmic phase for enzymatic assay. A strain that showed the highest enzyme activity was selected for optimization via response surface method (RSM). The parameters studied were incubation temperature (4 – 36 °C), pH media (4 – 10) and NaCl concentration (0 – 8%). Based on the OFAT results, all eight strains showed the highest growth rate at 20 °C, pH 7 and 4% (w/v) NaCl. The assay showed that the crude enzyme extracted from strain SC8 exhibited significantly higher activity (0.20 U and 0.37 U) than the positive control (0.11 U and 0.31 U) a","PeriodicalId":13439,"journal":{"name":"IIUM Engineering Journal","volume":"14 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82366097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-Objective Mayfly Optimization in Phase Optimization of OFDM","authors":"Abdul Azeez, S. Tarannum","doi":"10.31436/iiumej.v24i1.2625","DOIUrl":"https://doi.org/10.31436/iiumej.v24i1.2625","url":null,"abstract":"Communication systems have been used tremendously in recent years which results in the need for high data transmission rates. Orthogonal Frequency Division Multiplexing (OFDM) provides robust performance in frequency selective fading due to high bandwidth efficiency and inter-symbol interference. Various optimization techniques were applied in existing research to increase the efficiency of OFDM in a communication system. The existing research has a limitation of considering a single objective to improve the efficiency of OFDM and also has a local optima trap. This research proposes a Multi-Objective Mayfly algorithm (MOMF) to consider multi-objective and provides a proper trade-off between exploration and exploitation. The Partial Transmit Sequence (PTS) is applied in the model to test the performance. The FFT sizes and modulation orders are varied to evaluate the performance of the MOMF technique in phase optimization. The MOMF technique effectively increases the performance of the model than other existing optimization techniques. The MOMF technique provides a non-dominated solution to escape from local optima trap. The MOMF model considers PAPR, BER, and SER in MIMO-OFDM system to increase the efficiency of the system. The exploration-exploitation trade-off helps to improve the convergence and overcome local optima trap. The MOMF in OFDM phase optimization was evaluated using BER, SER, and Peak-to-Average Power Ratio (PAPR) metrics. The MOMF method has PAPR of 3.95 dB and PSO-GWO method has 4.92 dB of PAPR.\u0000ABSTRAK: Sistem komunikasi telah digunakan secara meluas sejak beberapa tahun ini dan dapatan kajian menunjukkan keperluan pada kadar transmisi data yang tinggi. Pemultipleksan Bahagian Frekuensi Ortogon (OFDM) menyediakan prestasi berkesan dalam pemilihan pemudaran frekuensi berdasarkan keberkesanan lebar jalur tinggi dan gangguan antara-simbol. Pelbagai teknik optimum digunakan pada kajian sebelum ini bagi meningkatkan keberkesanan OFDM dalam sistem komunikasi. Kajian tersebut mempunyai kekurangan dalam memilih satu objektif bagi membaiki keberkesanan OFDM dan juga mempunyai perangkap optima setempat. Kajian ini mencadangkan algoritma Mayfly Objektif-Pelbagai (MOMF) bagi memilih objektif-pelbagai dan menyediakan keseimbangan yang wajar antara eksplorasi dan eksploitasi. Urutan Pancar Separa (PTS) telah digunakan dalam model ini bagi menguji prestasi. Saiz FFT dan turutan modulasi dipelbagaikan bagi menguji keberkesanan teknik MOMF pada fasa pengoptimuman. Teknik MOMF dengan berkesan menaikkan prestasi model ini berbanding teknik-teknik sedia ada yang lain. Teknik MOMF menyediakan solusi kepada teknik bukan-dominasi bagi mengelak perangkap optima setempat. Model MOMF ini mengambil kira PAPR, BER, dan SER dalam sistem MIMO-OFDM bagi meningkatkan kecekapan sistem. Keseimbangan yang wajar antara eksplorasi-eksploitasi membantu dalam membaiki penumpuan dan mengatasi perangkap optima setempat. MOMF dalam fasa optimanisasi OFDM telah dinilai me","PeriodicalId":13439,"journal":{"name":"IIUM Engineering Journal","volume":"96 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72816258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Terminal Control Area Complexity Measurement Using Simulation Model","authors":"Rully Medianto, Naflah Mutiara Adinda, Y. I. Jenie, H. M. Pasaribu, Hari Muhammad","doi":"10.31436/iiumej.v24i1.2223","DOIUrl":"https://doi.org/10.31436/iiumej.v24i1.2223","url":null,"abstract":"Traffic density in the terminal control area will increase flight safety risks. One effort to reduce the risk is to minimize the controller’s workload when affected by air traffic complexity. This research uses a simulation model to measure air traffic complexity in terminal control areas. The aircraft performance model has been constructed from ADS-B data and represents the aircraft movement in the terminal control area of Soekarno-Hatta International Airport. The simulation model can detect and resolve conflicts to keep separations between aircraft at a specified minimum separation limit. Air traffic complexity measurement uses several indicators, i.e., aircraft density, number of climbing and descending aircraft, aircraft type mixing, conflict control, aircraft speed difference, and controller communication. The weighting factor for each indicator has been obtained from Jakarta Air Traffic Service Center (JATSC) controller perception using an analytic hierarchy process. The simulation results show that the variation of resolution type affects the complexity level significantly. The results of this study can be used as consideration for improving air traffic control procedures and air space structures.\u0000ABSTRAK: Kepadatan trafik di kawasan terminal kawalan bakal menyebabkan peningkatan risiko keselamatan penerbangan. Salah satu cara bagi mengurangkan risiko adalah dengan meminimumkan beban kerja pengawal yang terlibat dengan kesesakan trafik udara. Kajian ini menggunakan model simulasi bagi mengukur kesesakan trafik udara di kawasan terminal kawalan. Model pretasi pesawat telah dibina menggunakan data ADS-B dan ini mewakili pergerakan pesawat di terminal kawalan lapangan terbang antarabangsa Soekarno-Hatta. Model simulasi ini dapat mengesan konflik dan membuat resolusi bagi mengekalkan penjarakan antara pesawat mengikut had penjarakan  minimum yang ditetapkan. Beberapa indikator telah digunakan bagi mengukur kerumitan trafik udara, iaitu: ketumpatan pesawat, bilangan pesawat mendaki dan menurun, jenis pesawat, kawalan konflik, perbezaan kelajuan pesawat dan pengawal komunikasi. Faktor pemberat bagi setiap indikator telah diperoleh daripada pengawal persepsi Pusat Servis Trafik Udara Jakarta (JATSC) menggunakan proses analisis hierarki. Keputusan simulasi menunjukkan pelbagai jenis resolusi mempengaruhi tahap kerumitan dengan ketara. Hasil kajian ini boleh digunakan bagi menambah baik prosedur kawalan trafik udara dan struktur ruang udara.","PeriodicalId":13439,"journal":{"name":"IIUM Engineering Journal","volume":"8 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79284242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}