Pinsopon, Unnat
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Item type:Publication, Experimental study on sound characteristics of Ja-Khay strings(2019-07-01); ; This research explored sound characteristics of eight different strings on Ja-Khay, a Thai classical floor zither. The strings were investigated the suitability of being the first brightest string. Physical properties of each string such as linear density, elastic modulus and tension required to make a 262 Hz C<inf>4</inf>-note sound were tested and measured. The sound produced by each string was recorded in the recording studio of Music Engineering and Multimedia Department, King Mongkut's Institute of Technology Ladkrabang. Temporal and spectral responses of the sound produced by eight test strings were analyzed. The relationship between physical properties and sound characteristics such as maximum loudness, sustain, richness and brightness of the sound was investigated. The good sound characteristics of three most well-liked strings according to the survey: Construction string number 120, tennis string and Saw-U silk string, were confirmed by the analytical data. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Active Vibration Absorber with Curved Beam Design(2023-01-01); The project aims to design and create an active vibration absorber with a curved beam to reduce vibration. The selected frequency of the vibration generator for this research was limited to 10 to 30 revolutions per minute and is forced to move in one dimension. The vibration generator was controlled by variable resistance with an unbalanced mass that produces centrifugal forces between 14.799 and 133.189 newtons at frequencies of 10 and 30 revolutions per minute, respectively. To control the natural frequency of the active vibration absorber, the microcontroller STM32F103C8T6-Black Pill and absorption frequency was used with a set of controlling criteria that help to adjust a spring's stiffness. The spring was designed as a curve beam so that the absorber would be small and easy to use while having a wider working range and reacting quicker to a change in load. To reduce system vibration, the spring stiffness was properly adjusted by changing the curve beam's length by changing the locker arm's position using a rotating motor. The feedback control system, meanwhile, was used to adjust the motor's position through variable resistance and then calculate a feedback error to the corrected position, resulting in a natural frequency of the absorber that was similar to the system's vibration frequency. Moreover, the relationship between spring stiffness and curve beam length was also investigated to obtain the function of locker arm position and specify the angle of the motor's shaft. Experiments to test the correctness of theory and method were also conducted. Prior to the experiment, the vibration absorber's efficiency was assessed using ADAMS motion simulation software. The efficiency as a percentage drop in the main system vibration amplitude was calculated while the vibration absorber was mounted. At an operating frequency of 15 Hz, which is close to the natural frequency of the main system, the test results show that the vibration can be reduced by up to 65.49 percent. However, based on the experiment's results, the efficiency was defined as a percentage of a reduction in vibration amplitude in the primary system, both with and without an active absorber. The most efficiency as a percentage drop in the main system vibration amplitude was 34.917%, while the least efficient was 7.711%. It was concluded that the active vibration absorber design with the curved beam can reduce vibration, and while the results were not the best, they were enough to warrant the commencement of future studies. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A Study on Biogas Production Potential in Thailand 2019(2021-04-01) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Friction Compensated Fuzzy Force Tracking Control of Electro-Hydraulic System(2020-04-01) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Modeling of a SEPIC converter operating in continuous conduction mode(2009-10-22); A SEPIC (Single-Ended Primary Inductor Converter) DC-DC converter is capable of operating in either step-up or step-down mode and widely used in battery-operated equipment. There are two possible modes of operation in the SEPIC converter: Continuous Conduction Mode (CCM) and Discontinuous Conduction Mode (DCM). This paper presents modeling of a SEPIC converter operating in CCM using the State-Space Averaging (SSA) technique. The modeling leads to a small-signal linear model of the converter, from which the transfer functions used for feedback control design can be determined. Results are presented to verify the accuracy of the obtained model. ©2009 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A model-reference sliding mode for dual-stage actuator servo control in HDD(2014-01-01); Chatlatanagulchai, WithitThis paper presents a method of sliding mode control (SMC) designing and developing for the servo system in a dual-stage actuator (DSA) hard disk drive. Mathematical model of hard disk drive actuators is obtained, extracted from measuring frequency response of the voice-coil motor (VCM) and micro-actuator separately. The Matlab software tools are used for mathematical model estimation and also for controller design and simulation. A model-reference approach for tracking requirement is selected as a proposed technique. The simulation results show that performance of the model-reference SMC controller in DSA servo control can be satisfied in the tracking error, as well as keeping the positioning of the head within the boundary of +/-5% of track width under the presence of disturbance. The overall results of model-reference SMC design in DSA are met per requirement specifications and significant reduction in %off track is found when compared to the singlestate actuator (SSA). © 2014 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Fin Coil Dent Detection Using Deep Learning(2025-01-01); This work introduced the object detection using deep learning in order to detect and locate dents on fin coils. It was aimed at using the AI as a tool to detect fin coil dents and restore them in the fin coil manufacturing and assembly processes. Not only were the images of dents used to train object detection models, two different types of distinctive marks were added for the purpose of positioning calibration in the system. Three scalable models of the state-of-art EfficientDat D0, D1 and D2 were used and compared for their accuracies and performances. All models were trained successfully with the custom dataset. It took only 30 epochs to achieve a functionable performance. The dent detection accuracies which were considered from the True Positive, obtained from the D0, D1, and D2 models were 55%, 66% and 75 % respectively. The three models can identify additional marks with 100% accuracy. In all models, there was no False Negative detection in all object classes showing good potential of using the models in the real applications. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, PID electro-hydraulic cylinder force tracking system with friction compensation(2018-08-14) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Production Potential Assessment of Biogas from Napier Grass Using Geographic Information(2022-01-01) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Influence of RBD palm olein on hydraulic pump performance(2014-01-01)