Houngkamhang, Nongluck

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Integrated Innovative Technology

nongluck.ho@kmitl.ac.th

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Multi-Entropy Feature Extraction With LSTM Networks for Acoustic Emission-Based Railway Crack Localization
(2026-01-01)
Laon, Popphon
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Pourbunthidkul, Supavee
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Rattan, Praphaporn
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Sahavisit, Tanawit
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Suwansin, Wara
Railway infrastructure security is contingent upon the prompt identification of structural anomalies within steel tracks. This research establishes a framework that merges acoustic emission (AE) sensing with advanced machine learning for prompt fracture identification and location. To improve the quality of Raw AE signals, they are first cleaned using Kalman filtering to tackle environmental disturbances and ambiguous readings. The characteristics that arise from entropy comprising approximate entropy, Shannon entropy, and dimensional entropy are derived to delineate the temporal patterns of fracture-induced emissions. Density-based spatial clustering of applications with noise (DBSCAN) is applied to remove outliers during preprocessing. Long short-term memory (LSTM) networks classify crack locations into three anatomical regions: rail head, web, and foot. Experimental validation with 3,000 labeled AE signals (1,000 per class) under laboratory conditions, the full pipeline that integrates Kalman filtering, entropy features, DBSCAN, and an LSTM classifier attains an accuracy of 98.83%. With an entropy-based variant, the accuracy drops to 96.67%, confirming the incremental value of temporal denoising and outlier rejection. While using mel-frequency cepstral coefficient (MFCC) baseline achieves 97.67% accuracy, a deep neural network (DNN) trained on Kalman-filtered, entropy-based, and DBSCAN-processed inputs reaches 96.33% accuracy, underscoring the advantages of temporal modeling for AE. A GRU using the same Kalman-filtered, entropy-based, and DBSCAN-processed inputs, achieves 97.67% accuracy, but trails the LSTM overall. When deployed on actual railway lines with a mobile inspection platform, the system maintained robust performance, correctly identifying 84.67% of cracks at 3 km/h and 80.67% at 5 km/h. The LSTM configuration consistently outperformed all alternative approaches, including the entropy-only variant, MFCC-based method, DNN classifier, and GRU model. This confirms the LSTM’s enhanced capability to capture the temporal dynamics of AE signals, establishing it as the most effective framework for AE-based crack localization in railway structural health monitoring.
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Development of a Serological Dilution Microfluidic Chip for Immunoassay Applications
(2022-07-01)
Thienthong, Therdthai
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Juntasaro, Ekachai
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Khemthongcharoen, Numfon
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Sripumkhai, Witsaroot
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Houngkamhang, Nongluck
This work aims to develop a multiple dilution microfluidic chip that is capable of diluting the human serum by means of two-fold dilution for seven levels from 1:2 to 1:128 with phosphate-buffered saline (PBS) buffer. The dilution in this work is processed in parallel in order to reduce the accumulated errors that the standard pipetting technique generates in the micro-well plate. The serum and PBS buffer are precisely delivered to the micromixers by controlling their flow rates. The dilution is achieved by the passive mixing process for which the serpentine geometry is designed in order to continually generate the Dean vortices along the serpentine microchannel to effectively mix serum and PBS buffer in the microfluidic chip. The prototype of this multiple dilution microfluidic chip is fabricated by using polydimethylsiloxane (PDMS). The dilution-in-parallel capability of this prototype is validated by using the UV-vis absorption method. The results reveal that the measured values of the seven dilution ratios obtained are in good agreement with the exact values. Finally, this prototype is evaluated for serological MOG-IgG detection in order to verify the reliable operation of this multiple dilution microfluidic chip. The prototype can successfully detect MOG-IgG at all volume concentration ratios.
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Conjugation of antibody on gold nanoparticles for biosensors application
(2020-01-01)
Ta-Aithuak, Sarocha
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Loedsapchinda, Naruenard
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Houngkamhang, Nongluck
Regarding to the unique optical property and biocompatible, gold nanoparticles have been widely used to functionalize with antibodies probe for testing specificity with their antigen targets. The antibody immobilized onto gold nanoparticles which synthesized by different methods were studied. Gold nanoparticles synthesized by citrate reduction method and by using poly(ethylene)glycol (PEG) coated gold nanoparticles were immobilized with IgM antibody by physical adsorption. Gold nanoparticles before and after functionalize with antibodies were characterized with fourier-transform infrared spectroscopy (FTIR) for functional group and UV-Vis spectroscopy for absorption wavelength. Finally, a specificity test was conducted using spot of anti-IgM antibody onto nitrocellulose membrane to confirm the bioactivity of antibodies attached to gold nanoparticles.
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Fabrication of Al/Au hybrid SERS substrate using laser engraving for rapid detection of melamine and its analogues by hand-held Raman spectrometer
(2024-05-01)
Wongwasuratthakul, Puwasit
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Aumpalop, Weerada
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Chakaja, Chaiwat
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Satapornchai, Pemika
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Eiamsamut, Ploypailin
Surface-enhanced Raman spectroscopy (SERS), combined with a handheld Raman spectrometer, was utilized for the rapid and highly sensitive detection of melamine and its analogues. The investigation focused on the hybrid micro-nano structures of SERS-active substrates, fabricated by laser engraving aluminum (Al) sheets and depositing gold (Au) nanoparticles using magnetron sputtering. The laser engraving frequency was varied to get optimum SERS substrate. The fabricated SERS substrates were tested with rhodamine 6G (R6G) to optimize the Raman signal and subsequently detect melamine and its analogues viz., cyanuric acid, ammeline, ammelide in milk samples. The results demonstrated that a laser frequency of 20 kHz was the optimal condition for fabricating a micro-nano Al template with a depth of 61.21 μm, providing the highest Raman signal for R6G. The limit of detection (LOD) for melamine in mild acid solution and milk samples were determined to be 1x10-5 M and 1x10-4 M, respectively. The laser-engraved Al sheet technique offers a cost-effective approach for SERS substrate fabrication. The integration of the Al/Au hybrid SERS substrate with a hand-held Raman spectrometer demonstrates significant potential for detecting melamine and its analogues in realistic environments.
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Feasibility of Prediction Model for Internal Tumor Target Volume from 4-D Computed Tomography of Lung cancer
(2021-01-01)
Puangragsa, Utumporn
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Lomvisai, Pitchayakorn
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Phasukkit, Pattarapong
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Puangragsa, Sarut
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Setakornnukul, Jiraporn
4-Dimensional computed tomography (4DCT) is the most common technique to determine organ movement due to breathing motion. However, the ability of 4DCT to acquire CT images as a function of the respiratory phase increases higher radiation dose. To reduce the patient's radiation dose, this study created lung motion prediction models used to estimate tumor target movement in ten respiratory phases by detecting only external organ movement during a complete respiration cycle without radiation with Kinect. The average overall amplitude difference between RPM and Kinect signals in the phantom experiment was 0.02 ± 0.1 mm. F1 score of 100% for all most all classifications except classification 2,3,6,7 and 8 of 85%,83%,90%, 84%,85% where irregular breathing pattern. Essentially, the proposed tumor movement scheme's total accuracy (average of F1 scores) is 92.7 %. Deep learning model can predict tumor motion range and classification zone by used detection of the external respiratory signal
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PMMA/High-k Self-assembled TiO2 /PMMA Multi-layer Gate Dielectric for P3HT Organic Field Effect Transistors
(2022-01-01)
Inpor, Kroekchai
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Houngkamhang, Nongluck
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Thanachayanont, Chanchana
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Prichanont, Seeroong
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Kayunkid, Navaphun
In this work, a multi-layer structure of poly (methyl methacrylate)/ titanium dioxide/poly (methyl methacrylate) (PMMA/TiO₂ /PMMA; PTP) was proposed as a top-gate insulator for P3HT-based organic field-effect transistors (OFETs). Adding a TiO₂ interlayer as a high dielectric constant (high-k) material into PMMA film enables the modification of the dielectric constant of the multi-layers PTP film. The content of TiO₂ in the PTP film, which can be varied by changing the number of soaking cycles in TiO₂ solution, plays a crucial rule in modifying the dielectric constant of the PTP film. The higher the TiO₂ content used in the PTP film, the higher the dielectric constant of PTP film can be obtained. However, using high TiO₂ content led to a reduction in the dielectric constant of the PTP film due to leakage current induced by the agglomeration of TiO₂. The utilization of the top-gate insulator containing TiO₂ significantly enhanced several P3HT-OFETs characteristics, e.g., an increase in the I<inf>on</inf>/I<inf>off</inf> ratio, and a decrease in the threshold voltage. However, the use of the PTP top-gate insulator with a high content of TiO₂ resulted in regressions in the OFETs characteristics, such as a decrease in carrier mobility and reduction in the I<inf>on</inf>/I<inf>off</inf> ratio. OFETs operating at the optimum conditions of the PTP gate-insulator, with PTP thickness of 225 nm and RMS roughness of 20.0 nm, provided a dielectric constant of 7.13, a threshold voltage of-8.49 V, a saturation mobility of 2.2× 10-4 cm²V-1s-1, I<inf>on</inf>/I<inf>off</inf> ratio of 37.9, and a subthreshold slope of 0.39 V/decade.
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A Contactless Edge-AI Prototype for Simulated Apnea-like Respiratory Suppression and Motion Artifact Detection Using 60 GHz FMCW Radar
(2026-07-01)
Pairoch, Sathit
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Phasukkit, Pattarapong
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Houngkamhang, Nongluck
Sleep-related respiratory disturbances are difficult to monitor continuously outside specialized laboratories because conventional polysomnography is resource-intensive and intrusive. This study presents a contactless edge-AI engineering prototype for detecting controlled voluntary respiratory-motion suppression and motion artifacts using a 60 GHz frequency-modulated continuous-wave radar. The system integrates a 60 GHz radar front end, lightweight local preprocessing, an INT8 one-dimensional convolutional neural network deployed on the Analog Devices MAX78000 CNN accelerator (Analog Devices Thailand, Chon Buri, Thailand), and an event-driven Raspberry Pi Zero 2W gateway for alert transmission. Evaluation was performed using a controlled healthy-volunteer dataset consisting of normal breathing, voluntary breath-holding-induced respiratory suppression, and deliberate motion artifact. The final valid test set contained 270 technically valid 30 s windows balanced across the three classes. The INT8 model achieved an overall accuracy of 92.6% (95% confidence interval: 88.8–95.2%), with a macro-averaged precision, recall, and F1-score of 92.6%, 92.6%, and 92.5%, respectively. Active CNN inference on the MAX78000 consumed 0.152 ± 0.011 mJ and was completed in 5.20 ± 0.11 ms, corresponding to approximately 280-fold lower active inference energy than Python 3.14.6/TensorFlow Lite 2.21.0-based execution on the Raspberry Pi Zero 2W. These results demonstrate the feasibility of privacy-aware, low-power respiratory-pattern classification at the edge. However, the study should be interpreted strictly as an engineering proof-of-concept based on controlled voluntary breathing and movement tasks in healthy volunteers. It is not a clinically validated apnea or obstructive sleep apnea detection system and did not include polysomnography, oxygen saturation measurement, airflow sensing, sleep staging, or diagnosed patient cohorts.
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Study on detection of carbaryl pesticides by using surface-enhance raman spectroscopy
(2020-01-01)
Chakaja, Chaiwat
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Limwichean, Saksorn
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Nuntawong, Noppadon
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Eiamchai, Pitak
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Kalasung, Sukon
In this research, the Ag nanorod structure was used as surface enhanced Raman scattering (SERS) chip which provides a sensitive detection signal for trace analysis of carbaryl pesticide. Carbaryl in solid form was measured by using the standard Raman spectroscopy to investigate the spectrum. Carbaryl at various concentrations was prepared in acetonitrile and dropped on the SERS chip for measuring Raman spectrum by a portable Raman spectrometer. The measurement condition including laser power and exposure time were studied to test the performance of SERS chip for carbaryl detection. From the results, the SERS chip useful for enhancing the Raman scattering signal which was increased depending on the laser power and exposure time. Carbaryl can be detected on SERS chip couple with the portable Raman spectrometer with the limit of detection of 10-5 M.
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Demonstration of light absorption and light scattering using smartphones
(2020-01-01)
Malisorn, Khemchira
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Wicharn, Surawut
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Plaipichit, Suwan
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Pipatpanukul, Chinnawut
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Houngkamhang, Nongluck
This paper demonstrates the use of smartphones in an experiment of light absorption and light scattering. The LED display and camera of the smartphone are used as the light source and as the detector, respectively. The color wheel is used to choose the color of the light source to be shone through the sample for analysis. The detector directly measures the intensity of the light that passes through the sample to study light absorption according to the Beer-Lambert law. On the other hand, to investigate the light scattering, the detector orthogonally measures the intensity of the scattered light from the sample. The results of the light absorption correspond to the Beer-Lambert law. The scattered light from the sample is be measured by a smartphone. The experiment is easy to set up, without the need for any further expensive apparatus. We expect that this experiment will be useful for physics teachers to demonstrate light absorption and light scattering in the classroom or in a physics laboratory.
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Mixing-performance evaluation of a multiple dilution microfluidic chip for a human serum dilution process
(2021-09-30)
Thienthong, Therdthai
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Juntasaro, Ekachai
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Sripumkhai, Witsaroot
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Houngkamhang, Nongluck
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Chanasakulniyom, Mayuree
This paper is aimed to propose a numerically designed multiple dilution microfluidic chip that can simultaneously deliver several serum dilutions in parallel. The passive mixing scheme is selected for dilution and achieved by the serpentine mixing channel in which Dean vortices are induced to increase the contact area and time for better diffusion. The mixing performance at the exit of this dilution chip is numerically evaluated using five commonly-used mixing indices with the goal that the homogeneity of the mixture over the exit cross-sectional area of the mixing channel must be greater than 93.319% to fulfill the six-sigma quality control.

Houngkamhang, Nongluck

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