Retno Wigajatri Purnamaningsih
University of Indonesia
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Featured researches published by Retno Wigajatri Purnamaningsih.
Applied Physics Letters | 2016
Tomy Abuzairi; Mitsuru Okada; Retno Wigajatri Purnamaningsih; Nji Raden Poespawati; Futoshi Iwata; Masaaki Nagatsu
Ultrafine plasma jet is a promising technology with great potential for nano- or micro-scale surface modification. In this letter, we demonstrated the use of ultrafine atmospheric pressure plasma jet (APPJ) for patterning bio-immobilization on vertically aligned carbon nanotube (CNT) microarray platform without a physical mask. The biotin-avidin system was utilized to demonstrate localized biomolecule patterning on the biosensor devices. Using ±7.5 kV square-wave pulses, the optimum condition of plasma jet with He/NH3 gas mixture and 2.5 s treatment period has been obtained to functionalize CNTs. The functionalized CNTs were covalently linked to biotin, bovine serum albumin (BSA), and avidin-(fluorescein isothiocyanate) FITC, sequentially. BSA was necessary as a blocking agent to protect the untreated CNTs from avidin adsorption. The localized patterning results have been evaluated from avidin-FITC fluorescence signals analyzed using a fluorescence microscope. The patterning of biomolecules on the CNT mic...
INTERNATIONAL SYMPOSIUM ON FRONTIER OF APPLIED PHYSICS (ISFAP) 2015 | 2016
Andi Setiono; Rini Khamimatul Ula; Dwi Hanto; Bambang Widiyatmoko; Retno Wigajatri Purnamaningsih
In general, Fiber Bragg Grating (FBG) sensor works based on observation of spectral response characteristic to detect the desired parameter. In this research, we studied intensity response characteristic of FBG to detect the dynamic strain. Experiment result show that the reflected intensity had linier relationships with dynamic strain. Based on these characteristics, we developed the FBG sensor to detect low frequency vibration. This sensor is designed by attaching the FBG on the bronze cantilever with dimensions of 85×3×0.5 mm. Measurement results showed that the sensor was able to detect vibrations in the frequency range of 7-10 Hz at temperature range of 25-45 ˚C. The measured frequency range is still within the frequency range of digging activity, therefore this vibration sensor can be applied for oil pipelines vandalisation detection system.
International Journal of Electrical and Computer Engineering | 2018
Retno Wigajatri Purnamaningsih
Zigbee technology has been developed for short range wireless sensor networks and it follows IEEE 802.15.4 standard. For such sensors, several considerations should be taken including; low data rate and less design complexity in order to achieve efficient performance considering to the transceiver systems. This research focuses on implementing a digital transceiver system for Zigbee sensor based on IEEE 802.15.4 . The system is implemented using offset quadrature phase shift keying (OQPSK) modulation technique with half sine pulse-shaping method. Direct conversion scheme has been used in the design of Zigbee receiver in order to fulfill the requirements mentioned above. System performance is analyzed considering to BER when it encountered adaptive white Gaussian noise (AWGN), besides showing the effect of using direct sequence spread spectrum (DSSS) technique.The inverted pendulum is an under-actuated and nonlinear system, which is also unstable. It is a single-input double-output system, where only one output is directly actuated. This paper investigates a single intelligent control system using an adaptive neuro-fuzzy inference system (ANFIS) to stabilize the inverted pendulum system while tracking the desired position. The non-linear inverted pendulum system was modelled and built using MATLAB Simulink. An adaptive neuro-fuzzy logic controller was implemented and its performance was compared with a Sugeno-fuzzy inference system in both simulation and real experiment. The ANFIS controller could reach its desired new destination in 1.5 s and could stabilize the entire system in 2.2 s in the simulation, while in the experiment it took 1.7 s to reach stability. Results from the simulation and experiment showed that ANFIS had better performance compared to the Sugeno-fuzzy controller as it provided faster and smoother response and much less steady-state error.Association Rule mining plays an important role in the discovery of knowledge and information. Association Rule mining discovers huge number of rules for any dataset for different support and confidence values, among this many of them are redundant, especially in the case of multi-level datasets. Mining non-redundant Association Rules in multi-level dataset is a big concern in field of Data mining. In this paper, we present a definition for redundancy and a concise representation called Reliable Exact basis for representing non-redundant Association Rules from multi-level datasets. The given non-redundant Association Rules are loss less representation for any datasets.This paper presents a novel technique for numeral reading in Indian language speech synthesis systems using the rule-based Concatenative speech synthesis technique. The model uses a set of rules to determine the context of the numeral pronunciation and is being integrated with the waveform concatenation technique to produce speech out of the input text in Indian languages. To analyze the performance of the proposed technique, a set of numerals are considered in different context and a comparison of the proposed technique with an existing numeral reading method is also presented to show the effectiveness of the proposed technique in producing intelligible speech out of the entered text.This paper presents a data processing system based on an architecture comprised of multiple stacked layers of computational processes that transforms Raw Binary Pollution Data com- ing directly from Two EUMETSAT Metop satellites to our servers, into ready to interpret and visualise continuous data stream in near real time using techniques varying from task automation, data preprocessing and data analysis to machine learning using feed forward ar- tificial neural networks. The proposed system handles the acquisition, cleaning, processing, normalizing, and predicting of Pollution Data in our area of interest of Morocco.Advanced Communication Systems are wideband systems to support multiple applications such as audio, video and data so and so forth. These systems require high spectral efficiency and data rates. In addition, they should provide multipath fading and inter-symbol interference (ISI) free transmission. Multiple input multiple output orthogonal frequency division multiplexing (MIMO OFDM) meets these requirements Hence, MIMO-OFDM is the most preferable technique for long term evaluation advanced (LTE-A). The primary objective of this paper is to control bit error rate (BER) by proper channel coding, pilot carriers, adaptive filter channel estimation schemes and space time coding (STC). A combination of any of these schemes results in better BER performance over individual schemes. System performance is analyzed for various digital modulation schemes. In this paper,adaptive filter channel estimated MIMO OFDM system is proposed by integrating channel coding, adaptivefilter channel estimation, digital modulation and space time coding. From the simulation results, channel estimated 2×2 MIMO OFDM system shows superior performance over individual schemes.Electricity markets are different from other markets as electricity generation cannot be easily stored in large amounts and in order to avoid blackouts, the generation of electricity must be balanced with customer demand for it on a second-by-second basis. Customers tend to rely on electricity for day-to-day living and cannot replace it easily so when electricity prices increase, customer demand generally does not reduce significantly in the short-term. As electricity generation and customer demand must be matched perfectly second-by-second, and because generation cannot be stored to a large extent, cost bids from generators must be balanced with demand estimates in advance of real-time. This paper outlines a a forecasting algorithm built on artificial neural networks in order to predict short-term (72 hours ahead) wholesale prices on the Irish Single Electricity Market so that market participants can make more informed trading decisions. Research studies have demonstrated that an adaptive or self-adaptive approach to forecasting would appear more suited to the task of predicting energy demands in territory such as Ireland. Implementing an in-house self-adaptive model should yield good results in the dynamic uncertain Irish energy market. We have identified the features that such a model demands and outline it here.Received May 2, 2018 Revised Jul 9, 2018 Accepted Aug 2, 2018 Zigbee technology has been developed for short range wireless sensor networks and it follows IEEE 802.15.4 standard. For such sensors, several considerations should be taken including; low data rate and less design complexity in order to achieve efficient performance considering to the transceiver systems. This research focuses on implementing a digital transceiver system for Zigbee sensor based on IEEE 802.15.4. The system is implemented using offset quadrature phase shift keying (OQPSK) modulation technique with half sine pulse-shaping method. Direct conversion scheme has been used in the design of Zigbee receiver in order to fulfill the requirements mentioned above. System performance is analyzed considering to BER when it encountered adaptive white Gaussian noise (AWGN), besides showing the effect of using direct sequence spread spectrum (DSSS) technique. Keyword:This paper presents the use of Simelectronics Program for modeling and control of a two degrees-of freedom coupled mass-spring-damper mechanical system.The aims of this paper are to establish a mathematical model that represents the dynamic behaviour of a coupled mass-spring damper system and effectively control the mass position using both Simulink and Simelectronics.The mathematical model is derived based on the augmented Lagrange equation and to simulate the dynamic accurately a PD controller is implemented to compensate for the oscillation sustained by the system as a result of the complex conjugate pair poles near to the imaginary axis.The input force has been subjected to an obstacle to mimic actual challenges and to validate the mathematical model a Simulink and Simelectronics models were developed, consequently, the results of the models were compared. According to the result analysis, the controller tracked the position errors and stabilized the positions to zero within a settling time of 6.5sec and significantly reduced the overshoot by 99.5% and 99. 7% in Simulink and Simelectronics respectively. Furthermore, it is found that Simelectronics model proved to be capable having advantages of simplicity, less time-intense and requires no mathematical model over the Simulink approach.
AIP Conference Proceedings | 2018
Retno Wigajatri Purnamaningsih; Astari Widyakinanti; Arika Dhia; Muhammad Raditya Gumelar; Arif Widianto; Muhammad Randy; Harry Soedibyo
We proposed a respiratory monitoring system for living activities in human body based on fiber optic macro-bending for laboratory scale. The respiration sensor consists of a single-mode optical fiber and operating on a wavelength at around 1550 nm. The fiber optic was integrated into an elastic fabric placed on the chest and stomach of the monitored human subject. Deformations of the flexible textile involving deformations of the fiber optic bending curvature, which was proportional to the chest and stomach expansion. The deformation of the fiber was detected using photodetector and processed using microcontroller PIC18F14K50. The results showed that this system able to display various respiration pattern and rate for sleeping, and after walking and running activities in real time.
AIP Conference Proceedings | 2018
Arika Dhia; Kresna Devara; Tomy Abuzairi; Nyi Raden Poespawati; Retno Wigajatri Purnamaningsih
This paper reports the design of respiratory sensor using fiber optic for newborn incubator application. The sensor works based on light intensity losses difference obtained due to thorax movement during respiration. The output of the sensor launched to support electronic circuits to be processed in Arduino Uno microcontroler such that the real-time respiratory rate (breath per minute) can be presented on LCD. Experiment results using thorax expansion of newborn simulator show that the system is able to measure respiratory rate from 10 up to 130 breaths per minute with 0.595% error and 0.2% hysteresis error.
AIP Conference Proceedings | 2018
Tomy Abuzairi; Savira Ramadhanty; Dini Fithriaty Puspohadiningrum; Anita Ratnasari; Nji Raden Poespawati; Retno Wigajatri Purnamaningsih
Plasma activated water (PAW) is a new approach to bacterial inactivation while ensuring safety and maintaining the properties of the material sterilized. Reported research imply that PAW has been effective for inactivation of bacteria. In this paper, plasma treatment using atmospheric pressure plasma was demonstrated. Physicochemical properties such as pH, temperature, ORP, and nitrite concentration were assessed. The results suggest that plasma treatment causes acidification on water and generate reactive species, creating an environment suitable for killing bacteria. Therefore, plasma activated water is an assuring method for medical devices sterilization.Plasma activated water (PAW) is a new approach to bacterial inactivation while ensuring safety and maintaining the properties of the material sterilized. Reported research imply that PAW has been effective for inactivation of bacteria. In this paper, plasma treatment using atmospheric pressure plasma was demonstrated. Physicochemical properties such as pH, temperature, ORP, and nitrite concentration were assessed. The results suggest that plasma treatment causes acidification on water and generate reactive species, creating an environment suitable for killing bacteria. Therefore, plasma activated water is an assuring method for medical devices sterilization.
AIP Conference Proceedings | 2018
Tomy Abuzairi; Josef Stevanus Matondang; Retno Wigajatri Purnamaningsih; Basari; Anita Ratnasari
Cardiovascular disease has been one of the leading causes of sudden cardiac deaths in many countries, covering Indonesia. Electrocardiogram (ECG) is a medical test to detect cardiac abnormalities by measuring the electrical activity generated by the heart, as the heart contracts. By using ECG, we can observe anomaly at the time of heart abnormalities. In this paper, design of portable ECG device is presented. The portable ECG device was designed to easily use in the village clinic or houses, due to the small size device and other benefits. The device was designed by using four units: (1) ECG electrode; (2) ECG analog front-end; (3) DSO138; and (4) battery. To create a simple electrode system in the portable ECG, 1-lead ECG with two electrodes were applied. The analog front-end circuitry consists of three integrated circuits, an instrumentation amplifier AD820AN, a low noise operational amplifier OPA134, and a low offset operational amplifier TL082. Digital ECG data were transformed to graphical data on DSO138. The results show that the portable ECG is successfully read the signal from 1-lead ECG system.
international conference telecommunications and communication engineering | 2017
Retno Wigajatri Purnamaningsih; Nyi Raden Poespawati; Elhadj Dogheche
This paper reports the design of a four-branch optical power splitter using MMI structure and taper output branches in III-nitride semiconductors. The numerical experimental is conducted using the 3D FD-BPM method. The results show that the optical power splitter has an excess loss of 0.27 dB and imbalance of 0.12 dB. It is also shown that the proposed design can be realized for C band range. This result opens the opportunity for the future device using this technology.
2017 15th International Conference on Quality in Research (QiR) : International Symposium on Electrical and Computer Engineering | 2017
Maratul Hamidah; Sasono Rahardjo; Retno Wigajatri Purnamaningsih; Nji Raden Poespawati; Purnomo Sidi Priambodo
Ring Resonator has become one of the most interesting research topics nowadays since this device has high finesse value at resonance frequency and high sensitivity as well. There have been many scientific publications in the devices characteristic dynamic conditions, structures (single, multi and combination), and their applications as well, such as sensors, filters and others. The performance characteristics of double coupler structured single ring resonator has been discussed so far but the effect of coupling coefficient variation has not been discussed yet. Meanwhile, in previous research we have investigated the effect of coupling coefficient variation on single coupler structured single ring resonator. Now, we explore further the effect of coupling coefficient variation on the power transfer function output of a double couplers structured single ring resonator. Besides, single beam and double beams inputs are utilized to get the transmission powers as the output characteristics from both of drop and through ports of the ring resonator. The simulation results show, for the drop port output, as the higher coupling coefficient is, the peak of the power transfer function output gets higher for both the drop port output of single beam input and double counter directional inputs, but the double counter directional inputs, shows the peak of the power transfer function output much higher compared to its of the single beam input. Meanwhile for through port output, the result with double parallel inputs configuration shows a bit different behavior with its of single beam configuration, where as the result of the double parallel input configuration exhibits peak of the power transfer output almost similar to the simulation result utilizing single ring resonator with single coupler configuration that has already published previously. This simulation works may be useful in the design of resonator performance when transmission power is one of the important parameters to be considered.
2017 15th International Conference on Quality in Research (QiR) : International Symposium on Electrical and Computer Engineering | 2017
Retno Wigajatri Purnamaningsih; Nyi Raden Poespawati; Tomy Abuzairi; Sasono Rahardjo; Maratul Hamidah; Elhadj Dogheche
GaN-based structures have attracted many researchers in developing photonic devices. These semiconductor structures can operate at high temperatures and high-power levels due to their mechanical hardness. So far, optical splitters design based on Y-junction splitters are widely used on the various material structure. The problem of these structures is radiation loss at the junction area. In this paper, we study the effect of various waveguide parameters on GaN-based S-bend Y-junction optical power divider. The design consists of three sections: linear rectangular rib waveguide, parabolic taper and two S-bend sine branches with the total length of 1000μm. We use optical beam propagation methods (BPM) to obtain the characteristic of the guided wave to calculate the field propagation through the structure as a function of waveguide parameters, such as branching angle and input wavelength. All simulations are carried out using the OptiBPM software. From the simulation results, it shows that to maintain 90% transmitted power, the branching angle for the design should be at the range of 0.5–1.5°. It is also demonstrated that the transmitted power almost stable through the wavelength range from 1.5 up to 1.6 μm with an average of power loss at about 0.35 dB. The simulation results presented can be applied for future GaN Y-junction based waveguide photonic devices design.