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All Journal International Journal of Electrical and Computer Engineering Jurnal Teknologi Journal of the Indonesian Mathematical Society Journal of Engineering and Technological Sciences Journal of ICT Research and Applications Communication in Biomathematical Sciences TEKTRIKA - Jurnal Penelitian dan Pengembangan Telekomunikasi, Kendali, Komputer, Elektrik, dan Elektronika Indonesian Journal of Electrical Engineering and Computer Science
Roberd Saragih
Industrial And Financial Mathematics Research Group, Faculty Of Mathematics & Natural Sciences, Institut Teknologi Bandung
Computer Science & IT Electrical & Electronics Engineering Engineering Industrial & Manufacturing Engineering Mathematics Mechanical Engineering Social Sciences

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 1 
Controller Reduction of Parameter Dependent Systems Widowati Widowati; Bambang Riyanto; Roberd Saragih
Journal of Engineering and Technological Sciences Vol. 36 No. 1 (2004)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.eng.sci.2004.36.1.3

Abstract

This paper proposes a controller reduction of linear parameter dependent systems. A measure of the degradation is derived for the parameter dependent closed-loop performance caused by applying the reduced-order parameter dependent controller. This measure can be obtained by extending the degradation of the closed-loop performance of the balanced truncation of the corresponding time invariant systems. To verify the performance of the reduced-order controller, an application of the proposed controller reduction method to vertical acceleration of a missile is presented.
VIBRATION REDUCTION ON SINGLE-LINK FLEXIBLE MANIPULATOR USING H∞ CONTROL Roberd Saragih; Dede Tarwidi
Journal of the Indonesian Mathematical Society Volume 14 Number 2 (October 2008)
Publisher : IndoMS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22342/jims.14.2.52.73-82

Abstract

This paper is concerned with the vibration and position control of a single link flexible manipulator. Robot link manipulators are widely used in various industrial applications. It is desirable to build light weight flexible manipulators. Light flexible manipulators have a variety of applications, most significantly in space exploration,manufacturing automation, construction, mining, and hazardous operation. Timoshenko beam theory is used to derive mathematical model of a flexible manipulator. The dynamic equations of motion are obtained using the Lagrange's formulation of dynamics.The H∞ controller is designed for vibration and position control of the system. Simulations are presented and show that vibration and position control of a single flexible link can be controlled with the designed H∞ controller.DOI : http://dx.doi.org/10.22342/jims.14.2.52.73-82
FTR: Performance-Aware and Energy-Efficient Communication Protocol for Integrating Sensor Networks into the Internet Sinung Suakanto; Suhono H. Supangkat; S. Suhardi; Roberd Saragih
Journal of ICT Research and Applications Vol. 7 No. 1 (2013)
Publisher : LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.ict.res.appl.2013.7.1.5

Abstract

Integrating sensor networks into the Internet brings many advantages. For example, users can monitor or control the state of the sensors remotely without visiting the field. Some researchers have proposed methods using a REST-based web service or HTTP to establish communication between sensors and server via the Internet. Unfortunately, as we know, HTTP is a best-effort service. In some cases this means that if the number of sensors increases the end-to-end Quality of Service will decrease. The end-to-end network delay increases, as well as the failure rate of data sending caused by HTTP timeouts. In this paper, we propose Finite Time Response (FTR) HTTP as a communication protocol suitable for integrating sensor networks into the Internet. We have defined a cross-layer approach that coordinates between the application layer and the physical layer to control not only performance but also energy efficiency. The HTTP request-response delay measured at the application layer is used as the decision factor at the physical layer to control the active and sleep periods. We also propose a forced-sleep period as a control mechanism to guarantee average performance for all nodes. The experimental results have shown that FTR has the ability to maintain better performance, indicated by a lower average response time and a lower average timeout experience. Optimization is still needed to gain better performance and better energy efficiency while also considering the average value of the update time.
SISTEM KONTROL UMPAN BALIK UNTUK ALIRAN TCP PADA ROUTER SUATU JARINGAN KOMPUTER Adiwijaya Adiwijaya; Roberd Saragih; Bambang Riyanto T.
TEKTRIKA Vol 8 No 2 (2003)
Publisher : Telkom University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25124/tektrika.v8i2.226

Abstract

Perkembangan jaringan komputer yang pesat saat ini disertai pula dengan berbagai permasalahannya. Salah satunya adalah masalah kongesti. TCP (Transmission Control Protocol) merupakan protokol yang dapat mendeteksi kehilangan paket dan menginterpretasikan kehilangan tersebut sebagai indikasi telah terjadi kongesti pada jaringan. Makalah ini membahas tentang penghindaran kongesti dengan menggunakan mekanisme Active Queue Management (AQM). Langkah pertama yang dilakukan adalah membangun model matematika perilaku aliran TCP. Selanjutnya, menganalisis model tersebut sehingga masalah AQM dapat dipandang sebagai masalah kontrol umpan balik. Akhirnya, dengan menggunakan aproksimasi Padé untuk masalah delay, kontrol umpan balik disimulasikan dengan menggunakan pengontrol proporsional–integral–turunan (PID) sebagai pengontrol AQM.Kata Kunci : kontrol umpan balik, AQM, kontrol kongesti end-to-end, aproksimasi Padé, pengontrol PID
Stabilisasi Sistem Kontrol Bilinier Dengan Gangguan Menggunakan Linierisasi Eksak Dan Backstepping Khozin Mu’tamar; Janson Naiborhu; Roberd Saragih
Jurnal Teknologi Vol 14 No 1 (2021): Jurnal Teknologi
Publisher : Jurnal Teknologi, Fakultas Teknologi Industri, Institut Sains & Teknologi AKPRIND Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.34151/jurtek.v14i1.3549

Abstract

Sistem kontrol bilinear banyak digunakan dalam teknik dan kimia untuk memodelkan dinamika karena memiliki pendekatan dan kinerja yang lebih baik daripada sistem kontrol linier. Namun asumsi dan keterbatasan dalam pemodelan akan menghasilkan faktor ketidakpastian, yaitu berupa parameter taktentu dan fungsi gangguan. Pada artikel ini dibahas tentang desain kontrol pada sistem kontrol bilinier berorde dua dengan adanya fungsi gangguan. Diasumsikan sistem memiliki derajat relatif dua dan fungsi gangguan hanya berpengaruh pada dinamik variabel keadaan yang dikontrol. Sistem kontrol bilinier diasumsikan memiliki derajat relatif dua sehingga dapat ditransformasi secara eksak menjadi bentuk normal menggunakan transformasi umpan balik. Desain kontrol dilakukan berdasarkan sistem linier menggunakan metode backstepping. Hasil simulasi menunjukkan bahwa fungsi kontrol yang diperoleh dapat membawa luaran sistem dari titik awal menuju titik asal dalam waktu yang relatif singkat.
Tracking control for planar nonminimum-phase bilinear control system with disturbance using backstepping Khozin Mu`tamar; Janson Naiborhu; Roberd Saragih; Dewi Handayani
Indonesian Journal of Electrical Engineering and Computer Science Vol 26, No 3: June 2022
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v26.i3.pp1315-1327

Abstract

This article presents the design control of a tracking problem for a non-minimum phase bilinear control system containing disturbance. The bilinear control system is assumed to have a relative degree one and non-minimum phase, which means it has unstable internal dynamics. The disturbance exists only in state variables corresponding to the control function in external dynamics. The control design was carried out using the backstepping method, which was applied to the normal form of the bilinear control system. Internal dynamics will be stabilised using virtual control to overcome unstable internal dynamics. The last step will stabilise the external dynamics and disturbance using the original control function. The simulation results show that the proposed control method can rapidly drive the output to the given trajectory. Control performance varies depending on the control parameter setting. The higher the control parameter, the better the control performance, evaluated using integral absolute error.
Control Design for Dengue Fever Model with Disturbance Hanna Hilyati Aulia; Roberd Saragih; Dewi Handayani
Communication in Biomathematical Sciences Vol. 5 No. 2 (2022)
Publisher : Indonesian Bio-Mathematical Society

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/cbms.2022.5.2.3

Abstract

A mathematical model has become a useful tool to predict and control dengue fever dynamics. In reality, the dynamic of dengue fever transmission can be disturbed by uncertainty measurements, so it is needed to consider the disturbance in the model. Then, dengue fever model with disturbance is constructed by using a gain matrix consisting a covariance matrix and random vector. As dengue vaccine has been challenging to reduce the pandemic, a dengue model with vaccination as control is constructed. The aim is to propose a feedback controller that can reduces the infected human (H2 control problem) and the uncertainty measurements (H∞ control problem). The control u denotes the proportion of susceptible humans that one decides to vaccinate at time t. A random mass vaccination with wanning immunity is chosen because vaccine still on development process. A Design of mixed H2 - H∞ control with State-dependent Riccati Equation (SDRE) approach is applied. The SDRE has been an effective method to solve for synthesizing nonlinear feedback controller by transforming the system to an State-dependent coefficient (SDC) form. By comparing the mixed scheme with basic H∞, numerical simulation shows that the control application effectively decreases the number of infected humans and reduces the disturbance.
Genetic algorithm to optimization mobility-based dengue mathematical model Tegar Arifin Prasetyo; Roberd Saragih; Dewi Handayani
International Journal of Electrical and Computer Engineering (IJECE) Vol 13, No 4: August 2023
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijece.v13i4.pp4535-4546

Abstract

Implementation of vaccines, mosquito repellents and several Wolbachia schemes have been proposed recently as strategies against dengue. Research showed that the use of vaccine and repellent is highly effective when implemented to individuals who are in area with high transmission rates, while the use of Wolbachia bacteria is strongly effective when implemented in area with low transmission rates. This research is to show a three-strategy combination to cope with the dengue using mathematical model. In dengue mathematical model construction, several parameters are not yet known, therefore a genetic algorithm method was used to estimate dengue model parameters. Numerical simulation results showed that the combination of three strategies were able to reduce the number of infected humans. The dynamic of the human population with the combination of three strategies on average was able to reduce the infected human population by 45.2% in immobility aspect. Furthermore, the mobility aspect in dengue model was presented by reviewing two areas; Yogyakarta and Semarang in Indonesia. The numerical solutions showed that the trend graph was almost similar between the two areas. With the maximum effort given, the combination control values decreased slowly until the 100th day.
Evaluating the efficacy of univariate LSTM approach for COVID-19 data prediction in Indonesia Tegar Arifin Prasetyo; Joshua Pratama Silitonga; Matthew Alfredo; Risky Saputra Siahaan; Roberd Saragih; Dewi Handayani; Rudy Chandra
Indonesian Journal of Electrical Engineering and Computer Science Vol 34, No 2: May 2024
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v34.i2.pp1353-1366

Abstract

The coronavirus disease 2019 (COVID-19) pandemic, originating in 2020, has emerged as a critical global issue due to its rapid and widespread transmission. Indonesia, among the affected nations, has taken measures to address the situation, including the development of a deep learning model for predicting future COVID-19 infection and spread. This predictive tool serves as a valuable reference for the government and stakeholders, aiding them in making informed decisions and implementing appropriate measures to contain the virus. The deep learning model employs the long short-term memory (LSTM) algorithm, chosen for its ability to recognize temporal patterns in the country’s COVID-19 data. The model creation process involves data collection, preprocessing, model architecture planning, modeling, training, and evaluation. Two LSTM models were developed: a univariate and a multivariate model. Following thorough training and evaluation, the univariate model emerged as the superior choice, boasting evaluation metrics of 16.72 for mean absolute percentage error (MAPE) and 66.36 for root mean squared error (RMSE). This model was then deployed on a publicly accessible website, presenting visualizations of past COVID-19 data and predictions of future cases through line graphs. This user-friendly platform enables the public to access and analyze the data easily.
Co-Authors Adiwijaya Bambang Riyanto Bambang Riyanto T. Dede Tarwidi Dewi Handayani Dewi Handayani Hanna Hilyati Aulia Janson Naiborhu Janson Naiborhu Joshua Pratama Silitonga Khozin Mu'tamar Matthew Alfredo Prasetyo, Tegar Risky Saputra Siahaan Rudy Chandra S. Suhardi Sinung Suakanto Suhono H. Supangkat Widowati Widowati