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    Analysis of effective numerical aperture in 2-D photonic crystal waveguide
    (2014-01-01)
    Chantakit, T.
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    Yupapin, P. P.
    The effective numerical aperture calculation in two-dimensional Photonic crystal waveguide has been proposed. In this paper we present the analysis of ray optics refracted inside nano rods and at the boundaries between rods, which separates rod gap is much smaller than the incident wavelength assumed to reflect on the region. In operation, the resolving numerical aperture was compared with the finite difference time domain method via OptiFDTD software. Although numerical aperture mentioned above was found to be extremely close to fiber optics, a transmission passes though compartments of the rods are observed due to significant estimation of transmission and reflection of electric field. The compared simulation results will be discussed. By the aforementioned is that in the near future we will modify wave equation in periodic media of waveguide structures reached to the transverse electric equation of beam propagation in the two-dimensional Photonic crystal waveguide analysed. © (2014) Trans Tech Publications, Switzerland.
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    Growth stage detection for food consumption management in smart cricket farming using a deep learning technique
    This research proposed a novel method for tracking and predicting the growth stages of two-spotted crickets, reared in a temperature-controlled box at different growth stages using the YOLOv5s model. The images of crickets feeding inside the rearing box were taken with an infrared camera above the feeding point every hour. Images of the cricket were used to train a YOLOv5s model to detect crickets for each growth stage in the rearing box. The experimental results showed that the trained deep learning had an average accuracy of 95.7%. The relationship between the ratio of crickets at each growth stage throughout the 45-day rearing period was plotted and discussed. The results also showed a clear relationship between the amount of food consumed by crickets per day and their growth stage, which could be useful for appropriately managing food consumption according to the growth stage of crickets.
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    A nano-scale transducer using a PANDA type ring resonator for gas sensor applications
    (2012-03-01) ; ;
    Tipaphong, Weraphan
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    Yupapin, Preecha P.
    We present a new system of nano-scale gas sensor using PANDA type ring resonator, whereas the sensing unit is a splitting ring resonator with two and four gaps. The method of finite difference time domain (FDTD) via the computer programming called Opti-wave was used to analyze and simulated all the parameters. The two systems were compared and the simulation result shown that the system of four splitting gaps is better resolution and more linear relationship than two splitting gaps unit. Finally, we found that this system can be used to be a high-precision self-calibration nano-scale gas sensor with in the of resolution of 1 nm. © 2011 Elsevier GmbH. All rights reserved.
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    Accurate RMS calculations for periodic signals by Trapezoidal rule with the least data amount
    The purpose of this research is to present a simple method using the least data amount to calculate root mean square (RMS) values of periodic signals (constructed from Fourier series) which the highest harmonic order is known or able to be estimated. In the research, trapezoidal rule with the least data amount was proved and tried to calculate definite integral values of sinusoidal signals from a lot of trial runs until a significant property was found. Then the property would be deployed to calculate RMS values. Results of the research can provide not only more convenient processes of simple trapezoidal rule but also more accurate results than the patented Simpson's rule in the same least data amount. © 2013 Sompop Poomjan et al.
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    Design and simulation of asymmetric Y-junction beam splitter with controllable splitting based on adjusted air-hole defect
    We report a construction of a new asymmetric Y-junction beam splitter with a controllable splitting ratio and simulate this splitter. The splitter is based on InP, has the area 65.0 µm<sup>2</sup> and operates at the light wavelengths 1.48 and 1.55 µm. Under condition of no air-hole defect, the splitting ratio for the output ports 1 and 2 is equal to 92/8 at the both wavelengths. To control the splitting ratio, air-hole defects with different (diamond, square and cylinder) shapes are introduced at the junction between the two output ports. Our simulations confirm that the splitting ratio of the beam splitter can be efficiently controlled by changing the size and the shape of the air-hole defect. The maximal splitting ratios at our operating wavelengths are equal to 10/90 and 14/86 and the appropriate average insertion losses amount to 0.36 and 0.31 dB for all of defect shapes.
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    Multi-range Ammonia Gas Sensor Control and Monitor via IoT System
    (2022-01-01)
    Kruakuanphet, Aphichaya
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    Phongwisit, Phachara
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    In this paper, we present a multi-range of ammonia gas concentration control and monitoring via IoT system. We can select the ammonia gas concentration measurement range by adjusting load resistance within the voltage divider circuit. The appropriate measurement range, which corresponds to the concentration of ammonia gas produced by agricultural and industrial activities, can control and monitor via Blynk application. The MQ-137 gas sensor is selected as the main sensor, and each load resistance condition within the voltage divider circuit is calibrated with known ammonia gas concentration inside a calibration box. The calibration data is input into computer programming and processed by ESP8266 microprocessor. After calibration, we obtained a multi-range ammonia gas sensor suitable for measuring the ammonia gas concentration for each concentration range. The experiment showed that load resistance affects the measurement accuracy of ammonia gas concentration. We can select the load resistance suitable for the ammonia gas concentration and display on a smartphone via IoT system.
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    Proof of using fourier coefficients for root mean square calculations on periodic signals
    The purpose of this work is to academically prove using Fourier coefficients of periodic signals for root mean square (RMS) calculations. In the detail, properties of Fourier series are brought to calculate RMS values of periodic signals obviously. Results from this work can confirm that this method is more convenient, efficient and simple for RMS calculations than Calculus integration technique (if Fourier coefficients are given) and can be cited for further researches. © 2014 Sompop Poomjan et al.
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    A self-calibration nano-scale sensing transducer using PANDA ring resonator
    (2010-12-01) ;
    Tipaphong, W.
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    Yupapin, P. P.
    We propose a new system of self-calibration measurement using a nano-scale sensing transducer, which is known as a PANDA ring resonator type, whereas the sensing unit is combined into the system by mean of one ring, and the other ring is set as a reference signal. We use the method of finite difference time domain (FDTD) via the computer programming called Opti-wave to analyze and simulate. The simulation result has shown that we can use this system for high-precision and self-calibration measurement using a nano-scale sensing transducer, whereas the measurement resolution of 1 nm can be obtained. The recovery and the reciprocal signals can also be formed, which can be used to approach to many advantages of measurements, including the possibility of standardizing measurement accuracy. ©2010 IEEE.
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    Electronic nose ammonia gas monitoring via IoT system for Chlorella sp. cultivation
    (2023-01-01) ;
    Kruakuanphet, Aphichaya
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    Phongwisit, Phachara
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    In this paper, we present an electronic nose ammonia gas monitoring via IoT system for Chlorella sp. cultivation. The MQ–137 gas sensor module is selected as the primary sensor for measuring ammonia gas concentration. The pH sensor module is the sensor for measuring the pH levels in Chlorella sp. ponds. The MQ–137 gas sensors are calibrated with a known concentration of ammonia gas in the calibration box. Calibration conditions are set corresponding to low concentration of ammonia gas produced by Chlorella sp. cultivation. The pH sensor module is calibrated against a standard pH buffer. The calibration data obtained from the calibration method is input into computer programming and processed by the ESP8266 microprocessor. After calibration, the MQ–137 gas sensor and pH sensor modules are used to measure the ammonia gas concentration and pH levels in the Chlorella sp. ponds. Chlorella sp. is cultivated under three conditions of light intensity, natural light with an average light intensity of 1521 Lux, and artificial light with a light intensity of 1000 Lux and 2000 Lux, respectively. The ammonia gas concentration and pH levels of Chlorella sp. cultivation are transferred to the cloud system and displayed via the IoT system. And the system can also send a notification to a smartphone when ammonia gas concentration and the pH levels reach the specified value.
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    360 degree white light holography display on surface of transparency conical cup
    (2021-01-01) ;
    This paper presents the method and experimental results of the construction and reconstruction of three dimensions conical holography. He-Ne laser is used as the construction light source. Then the construction light is shone on top of a transparency conical cup, where a plain holographic film is wrapped around and attached to its surface. The object is located at the bottom of the cup. In this manner, the cup acts as a captured screen. After exposure, the film is developed and fixed by a chemical solution. The three-dimensional holography is recorded in the film. For reconstruction, we used red LED and flashlight as a reconstruction light source. The film is wrapped around and attached to the surface of the cup again. When the reconstruction light shines on the cup, the three-dimensional holography appears in the center of the cup. The cup is rotated in step, each step is 45 degrees, and the image is recorded by the digital camera. Experimental results show that the 360 degrees three-dimensional holographic image is successfully reconstructed. In conclusion, we could apply the method to create a three-dimensional holographic for displaying in all directions.