• The Journal of Asian Finance, Economics and Business
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• v.8 no.7
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• pp.181-193
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• 2021

Thailand's tourism industry contributed to over three trillion baht in 2019. Tourist attractions across Thailand attract tourists around the world with their natural scenery, lifestyles, and cultures, especially in those called "second-tier cities". Community enterprises play a vital role to drive the tourism industry to local areas. However, most community enterprises lack professional accounting knowledge. This research aims to provide guidelines for ecotourism cost management of community enterprises in Thailand. Participatory Action Research (PAR) was employed to investigate the current circumstances of the Banlaem enterprise by using in-depth interviews to identify problems in cost management. Then, the focus and small group meetings were organized to monitor and evaluate solutions. The results reveal that the cost of VIP-Two Days trip was generating the highest net profit and margin, followed by VIP-One Day trip, but net losses were detected on the Students-One Day trip, even though income was greater than the variable costs, revenues didn't cover fixed costs. Thus, accounting knowledge could be a major concern of these enterprises. They should systematically record revenues and expenses, set appropriate labor costs, reduce production costs by using seasonal seafood and make use of vegetables in their gardens, and price products according to their production costs.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.9
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• pp.1300-1305
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• 2014

In this paper, we suggest an optimization method which can save about 5[%] of the cost though the optimizing of configuration and capacity for the facility. To achieve this goal, we compared the design data of the power, motor and drive system with the actual operation data of the plate mill plant in K-Steelworks. Therefore we measured the actual loading data by facilities considering the operating conditions of the plate mill plant in K-Steelworks, after that analyzed these data. In addition, we review the optimal capacity for transformer, switchgear and drive, and also reconfigured the electrical room and power single line diagram through the validation of motor data by equipment and the confirmation of process data considering the load characteristics. Consequently, the optimization method of capacity for the facilities shall have effectiveness in building new plate mill plant to further reduce costs at future.

• Journal of Drive and Control
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• v.9 no.4
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• pp.58-61
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• 2012

The customers who used the hydroulic system desire the product that has more detailed specification quickly during the industrial technology is developed. Every researcher try to reduce the developed period and to satisfy the customers' desire. Lot's of simulation software and hardware already was used to be satisfied those purpose. But these kind of equipment need a lot of cost to set up and technical knowledge to drive that system. This paper concerns about analog PID controller that can be assembled with a few resistor, condenser and optional amplifier and doesn't need technical knowledge to drive. At the first, the plant was modeled mathematically to design the analog PID controller's circuit. After that, PID controller's parameter was selected by customers' desire. Finally, the analog PID controller's circuit was assembled from the control law. The circuit's availability was confirmed by step response test in the controlled system.

• Journal of Electrical Engineering and Technology
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• v.11 no.3
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• pp.670-674
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• 2016

The control performance of hybrid PWM inverter using a phase current measurement is presented in this paper. The hybrid PWM technique consists of space vector pulse width modulation (SVPWM) and six-step voltage control operation. The SVPWM is performed to reduce the harmonic components in the low speed region, and the six-step modulation is applied to increase the maximum speed of the IPMSM in the high speed region. Therefore, it is possible to obtain a great performance in both the low speed range and high speed range. However, the six-step modulation cannot be completely implemented, since the inverter that includes the lag-shunt sensing method has an immeasurable current region. In this paper, a quasi-six-step modulation using a modified voltage vector is proposed. The validity and usefulness of the proposed PWM technique is verified by MATLAB/Simulink and experimental results.

• Journal of Power System Engineering
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• v.10 no.4
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• pp.181-186
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• 2006

In this paper, a noncontact type torque meter using silicone rubber to measure the exact torque value and reduce a vibration and a noise, was developed. When planetary gear speed reducer runs, torque, RPM etc.. of motor change according to load or speed change. So, it needs a device to detect load's change or to diagnose the state of thewhole drive department by monitoring these result values. The noncontact type torque meter using silicone rubber that we're trying to develop this time is low-cost and can measure RPM and torque value simply. Also, it caculate a power using this value and indicate them on screen.

• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.5
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• pp.391-398
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• 2014

This paper presents a resonant step-down DC/DC converter to reduce the voltage stresses of a 3-phase inverter module under the three-phase AC utility line condition. Under this condition, a conventional 3-phase inverter module suffers from high voltage stresses as a result of the high rectified DC link voltage; hence, a high-cost high-voltage-rating inverter module must be used. However, using the proposed converter, a low-cost low-voltage-rating inverter module may be adopted to drive the motor even under the 3-phase AC line condition. The proposed converter, which can be realized with small size inductor and low-voltage-rating semiconductor devices, operates at a high-efficiency mode because of the zero-current switching operations of all the semiconductor devices. The operational principles are explained and a design example is provided in the study. Experimental results demonstrate the validity of the proposed converter.

• The Journal of Korea Robotics Society
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• v.8 no.1
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• pp.43-50
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• 2013

$A^*$ algorithm is a global path generation algorithm, and typically create a path using only the distance information. Therefore along the path, a moving vehicle is usually not be considered by driving characteristics. Deceleration at the corner is one of the driving characteristics of the vehicle. In this paper, considering this characteristic, a new evaluation function based path algorithm is proposed to decrease the number of driving path corner, in order to reduce the driving cost, such as driving time, fuel consumption and so on. Also the potential field method is applied for driving of UGV, which is robust against static and dynamic obstacle environment during following the generated path of the mobile robot under. The driving time and path following test was occurred by experiments based on a pseudo UGV, mobile robot in downscaled UGV's maximum and driving speed in corner. The experiment results were confirmed that the driving time by the proposed algorithm was decreased comparing with the results from $A^*$ algorithm.

• The Transactions of the Korean Institute of Power Electronics
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• v.11 no.4
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• pp.328-339
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• 2006

In this paper the characteristic analysis of a single-phase switched reluctance motor (SRM) drive system with power factor correction (PFC) circuit is presented. The SRM is a low cost, simple and has a good high speed performance. The SRM drive with diode rectifier and filter capacitor has a low power factor because of short switch on time of capacitor. A novel switching topologic is presented to improve power factor and reduce torque ripple based on analysis of PFC circuit. Accordingly the SRM drive system with PFC circuit is also presented. Through the numerical analysis of the system, the toque ripple, power factor and efficiency with the change of rotary speed, load torque and capacity of the capacitor are achieved and compared with actual measured value.

• International Journal of Automotive Technology
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• v.8 no.6
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• pp.781-790
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• 2007

Hybrid electric vehicles(HEV) combined with more than one power sources have great potential to improve fuel economy and reduce pollutant emissions. The Integrated Starter Generator(ISG) HEV researched in this paper is a two energy sources vehicle, with a conventional internal combustion engine(ICE) and an energy storage system(batteries). In order to investigate the potential of diesel engine hybrid electric vehicles in fuel economy improvement and emissions reduction, a Dynamic Programming(DP) based supervisory controller is developed to allocate the power requirement between ICE and batteries with the objective of minimizing a weighted cost function over given drive cycles. A fuel-economy-only case and a fuel & emissions case can be achieved by changing specific weighting factors. The simulation results of the fuel-economy-only case show that there is a 45.1% fuel saving potential for this ISG HEV compared to a conventional transit bus. The test results present a 39.6% improvement in fuel economy which validates the simulation results. Compared to the fuel-economy-only case, the fuel & emissions case further reduces the pollutant emissions at a cost of 3.2% and 4.5% of fuel consumption with respect to the simulation and test result respectively.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.455-460
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• 2004

The Fuel cell Rubber tired Train (FRT), which is now getting the attention as the next generation vehicle with its environment-friendliness, is the transportation for smooth connections of city traffic. It is the revival of the surface-car system with its revaluation of the function and technological development. Accordingly, fixed time operation and high speed driving became possible. FRT is operated together with other vehicles on the regular drive way. While this vehicle can solve the problem of traffic congestion in the urban area, it also can be cost-effective when it is compared to the cost of subway construction. It is also designed to minimize the underground or elevated traffic lane, to introduce the new construction technology, to reduce a term of works, and to cut down the operation cost by unmanned automatic driving system. Furthermore, it is considered as the alternative measure of other transportation due to its potential for the ecological way of speed improvement and the accessability to the disabled, elderly and children by developing the vehicle with folding steps or by building the high boarding platforms. In this research, I concentrated on the user oriented interior design of the FRT to make it passenger-friendly and safe in order to maximize the utilization of the vehicle so that all users including wheelchaired, user with baby carriage, elderly and children can conveniently use this vehicle.