19672 research outputs found
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High sensitive temperature sensor silicon-based microring resonator using the broadband input spectrum
No full textA sensitivity enhanced optical temperature sensor has been investigated and developed based on a silicon oxynitride (SiON) waveguide microring resonator (MRR). The broadband supercontinuum (SC) output from a fiber laser cavity is injected into the input port of the MRR, where the output was detected at the drop port of MRR. The results can be useful for the sensor-based waveguide devices, where the applications such as the temperature sensors can be realized. The temperature sensor has been fabricated in an MRR-silicon base structure. Experimental characterization of inserting the SC as input source into the MRR as the temperature sensors were carried out. The advantage of using the SC as input source is that the sensor covers a wide range of wavelengths, thus sensing the temperature changes in the wide wavelength ranges which can extend the sensing device applications. This study opens a way to apply optical sensors by using broadband SC as a source for manufacturing temperature environments sensors within the MRR waveguide structures. This will enhance the ability of the current temperature sensors to function at different and long wavelength band
A widely tunable dual-wavelength based on a microring resonator filter device
No full textWe demonstrate a stable, tunable dual-wavelength (DW) generated by launching an in-house built supercontinuum (SC) into an add-drop microring resonator (MRR). The MRR is fabricated from a silicon-nitrogen-oxygen substrate. The frequency comb of the filtered SC is obtained with an experimental free spectral range (FSR) from 0.39 to 0.46 nm corresponding to 48.7-57 GHz within the wavelength range 1520-1660 nm. The stability of a generated DW within the ranges 1561.16 and 1561.57 nm over 120 min is examined, where high, stable DW with a very low power fluctuation is achieved. This work has demonstrated the use of waveguide based MRR in the fiber laser system, and a remarkable flat and low power fluctuations frequency comb is achieved using the in-house built SC source and MRR
Computation of ion exchange buried microring resonator waveguide for THz communication applications
No full textThe ion exchange creates the optical buried waveguides, whereas it is the method that the glass doping occurs with the condition of existence of the mobile metal ions. The most common ion used is silver (Ag+) due to its broad variation in the refractive index. The proposed application presented in this work is to use the microring resonator (MRR) system based on the buried waveguides simulated by the ion exchange method. The passive MRRs are realized as the multi-wavelength transceiver, applicable in optical technologies such as the optical sensing, Terahertz (THz) communication and optical switching. The cross-sectional view of the simulated buried optical waveguide for the Ag+ concentrations of 0.8 mol/m3 is presented. The fundamental mode propagation is simulated using the time-domain traveling wave method, where the simulation of the optical power flow density and the electric field distributions of the buried waveguides were performed. The two coupled MRRs are used to generate tunable dual-wavelength with spacing in the range of Terahertz (THz). As results, the dual wavelengths in the range between 0.25 and 0.96 THz were generated at the throughput and drop port of the MRRs system
Dual wavelength optical duobinary modulation using GaAs–AlGaAs microring resonator
No full textIn this article, optical duobinary modulation technique has been used for modulating the dual-wavelength optical signal generated by the microring resonator system. The optical signals are de-multiplexed to two different optical signals with center wavelength of 1540 and 1545 nm afterward, these are modulated and transmitted over an optical fiber communication system, where the high performance of the transmitted signals is obtained. The NRZ binary signals are used to modulate the optical signals. The high-quality factor and performance of the system has been investigated by applying an optimization through the system parameters, where significant improvement could be obtained and highest quality factor of 32.871 shows the successful transmission. The second wavelength of the dual-wavelength has undergone the same modulation technique and has experienced the optical transmission after the system optimization has been performed, where the quality factor for the received optical signal at 1545 nm center wavelength is 39.282. These results show the introduced modulation technique is suitable to apply for the optical signals generated by the microring resonators
Efficacy of Mosquito Coils: Cross-resistance to Pyrethroids in Aedes aegypti (Diptera: Culicidae) From Indonesia
No full textAedes aegypti (L.) (Diptera: Culicidae) is the primary vector of several arthropod-borne viral infectious diseases globally. Relentless vector control efforts are performed to curtail disease transmissions, insecticides remain as the first line of defense in Indonesia. With a dearth of publication on the efficacy of mosquito coil in Indonesia, this is the first report related to mosquito coil despite its common use in households. Ae. aegypti mosquitoes were sampled from nine regencies in Indonesia and tested using the glass-chamber method against three commercially available local pyrethroid-based mosquito coils containing d-allethrin, transfluthrin, and metofluthrin. The 50% knockdown time of female Ae. aegypti tested with d-allethrin, transfluthrin, and metofluthrin containing coils ranged from 0.65 to 14.32; 0.8 to 16.4; and 0.78 to 20.57 min, respectively. Mortality rates in accordance with WHO resistance indicators showed that strains from Denpasar, Mataram, Kuningan, Padang, Samarinda, and Sumba Timur were resistant (98% mortality rate) to the active ingredients assayed. Moreover, the knockdown rates between d-allethrin and transfluthrin, d-allethrin and metofluthrin, as well as transfluthrin and metofluthrin displayed significant associations, portraying the presence of cross-resistance within pyrethroid insecticides. The minimal insecticidal effect of mosquito coils against some Indonesian Ae. aegypti also pointed out the development of pyrethroid resistance, prompting a revamping of the vector control system
A New Local Fractional Entropy-Based Model for Kidney MRI Image Enhancement
No full textKidney image enhancement is challenging due to the unpredictable quality of MRI images, as well as the nature of kidney diseases. The focus of this work is on kidney images enhancement by proposing a new Local Fractional Entropy (LFE)-based model. The proposed model estimates the probability of pixels that represent edges based on the entropy of the neighboring pixels, which results in local fractional entropy. When there is a small change in the intensity values (indicating the presence of edge in the image), the local fractional entropy gives fine image details. Similarly, when no change in intensity values is present (indicating smooth texture), the LFE does not provide fine details, based on the fact that there is no edge information. Tests were conducted on a large dataset of different, poor-quality kidney images to show that the proposed model is useful and effective. A comparative study with the classical methods, coupled with the latest enhancement methods, shows that the proposed model outperforms the existing methods
Reservoir inflow forecasting with a modified coactive neuro-fuzzy inference system: a case study for a semi-arid region
No full textExisting forecast models applied for reservoir inflow forecasting encounter several drawbacks, due to the difficulty of the underlying mathematical procedures being to cope with and to mimic the naturalization and stochasticity of the inflow data patterns. In this study, appropriate adjustments to the conventional coactive neuro-fuzzy inference system (CANFIS) method are proposed to improve the mathematical procedure, thus enabling a better detection of the high nonlinearity patterns found in the reservoir inflow training data. This modification includes the updating of the back propagation algorithm, leading to a consequent update of the membership rules and the induction of the centre-weighted set rather than the global weighted set used in feature extraction. The modification also aids in constructing an integrated model that is able to not only detect the nonlinearity in the training data but also the wide range of features within the training data records used to simulate the forecasting model. To demonstrate the model’s efficacy, the proposed CANFIS method has been applied to forecast monthly inflow data at Aswan High Dam (AHD), located in southern Egypt. Comparative analyses of the forecasting skill of the modified CANFIS and the conventional ANFIS model are carried out with statistical score indicators to assess the reliability of the developed method. The statistical metrics support the better performance of the developed CANFIS model, which significantly outperforms the ANFIS model to attain a low relative error value (23%), mean absolute error (1.4 BCM month−1), root mean square error (1.14 BCM month−1), and a relative large coefficient of determination (0.94). The present study ascertains the better utility of the modified CANFIS model in respect to the traditional ANFIS model applied in reservoir inflow forecasting for a semi-arid region
High impedance fault detection and identification based on pattern recognition of phase displacement computation
No full textThis paper proposes a new algorithm for high-impedance-fault (HIF) detection based on phase displacement computation (PDC). The PDC is calculated between the measured and reference three-phase voltage signals. There are two stages in this algorithm. In the first stage, the pattern of the PDC is analyzed to detect the occurrence of an event. In the second stage, the peak of the PDC is used as a feature to distinguish between HIF and non-HIF events. Subsequently, an automatic HIF classification algorithm based on predefined indices is proposed to perform event identification and HIF detection. Different types of HIF events and non-HIF events, such as load switching, motor starting, and capacitor switching, have been simulated in PSCAD/EMTDC. The proposed algorithm is able to classify the events accurately for both single and multiple events occurrence
Effect of stirring time on the structural parameters of nanophotonic LiNbO 3 deposited by spin-coating technique
No full textLithium niobate (LiNbO3) photonic crystals are deposited on quartz substrate by using spin coating technique. The mixture is prepared with different stirring time (8 h, 24 h, 48 h). The LiNbO3 nanostructures are analyzed by X-ray diffraction. The results show that as mixing time increases, the XRD starts to become structurallymore regular and high crystallization, therefroe it is found that the best mixing time was 48 h related to ideal syntheiss. The effect of different annealing temperatures (400, 500, and 600 °C) on the structural properties is elaborated studied towards finding ideal conditions for the preparation of optical waveguides
Batik Artisans’ judgment of batik wax quality and its criteria: An application of the Many-facet Rasch Model
Get PDFBatik is a traditional dyeing technique that uses hot melted wax on natural fabric. The wax is applied to the fabric, left to dry, then the fabric is dyed using cold water dyes. Wax quality is central to the batik process and, in the Indonesia region, there are ten standard criteria used to measure the batik wax quality. This study used five batik wax samples tested by twenty batik artisans according to those standard evaluation criteria, and the ensuing data were analyzed using the many-facets Rasch Model. The study found that one criterion, the cost of wax making is regarded as the most difficult item for the batik artisans to endorse. Two criteria for judging batik wax quality, namely ‘easy to set’ and ‘not sticky’ are two items that elicited unexpected responses from raters