• Textile Coloration and Finishing
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• v.11 no.2
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• pp.64-74
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• 1999

The driving characteristics of the 1 tube 2 chamber bent silkworm type dyeing machine are reported. This dyeing machine is a newly developed energy saving machine. In this study, the driving characteristics of the 1 tube 2 chamber bent silkworm type dyeing machine are examined. Specially the relationship between main body pressure and the electric current of the blower motor, the relationship between main body pressure and the air pressure of the blower nozzle, the effect of the air pressure of the blower on the running speed of the fabric, and the effect of main body temperature were discussed experimentally. Through the experimental data, the following results were obtained. 1. Blower motor electric current and blower nozzle air pressure increased as main body pressure increased due to the temperature increase of the main body. 2. The running speed of the fabric increased as blower nozzle air pressure increased. The difference in running speed between winch reel driving and no winch reel driving at a blower frequency of 60Hz was higher than that of 70Hz. 3. The electric current of the blower rioter and blower nozzle air pressure increased rapidly at the initial state. As the experimental time passed, the main body pressure increased slowly. as the main body temperature increased.

• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.4
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• pp.867-875
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• 2014

Planing crafts were specifically designed to achieve relatively high speeds on the water. When a planing craft is running at high speed, dynamic pressure on the bottom makes the boat rise on the surface of the water. This reduces the area of the sinking surface of the boat to increase air resistance. Air resistance means the resistance that occurs when the hull and deck house over the surface of the water come in contact with the air current. In this paper, we carried out a CFD numerical analysis to find optimal deck houses that decreased air-resistance on the water when planing crafts are running at high speed. We finally developed the deck house shape of high-speed planing crafts that optimally decreased air resistance.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2002.11a
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• pp.97-102
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• 2002

Resident's agreeableness anger elevation request by improvement of life environment with economy development is increasing recently. However, research about air current estimation in dwelling environment that make use of air conditioner summer and cooling room is lacking going yet much. We are going to prefer most air current pattern(speed 3 steps of swing) that offer in PAC after figure processing because user's life hysteresis and present air current pattern that is supposed and offer more agreeable environment to room resident.

• Journal of Electrical Engineering and Technology
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• v.6 no.5
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• pp.640-646
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• 2011

The current study presents the design and performance of a novel 4/2 switched reluctance motor (SRM) for a high-speed air blower. With a comparative study of some rotor structures for a high-speed drive, a stepper-type rotor is optimized to produce a continuous torque and a low torque ripple. Rotor pole arc is modified to have a wide continuous output torque region, and air gap is determined to develop less torque ripple. The rotor radius is determined to reduce torque ripple with a reiterative FEM analysis. The designed rotor has three regions: short uniform, long uniform, and nonuniform air-gap region. The positive torque region is wider than a conventional 4/2 SRM without any torque dead zone. A prototype is tested and the efficiency is up to 72[%] at 30,000[rpm], 600[w] output.

• Advances in materials Research
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• v.13 no.1
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• pp.1-18
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• 2024

The present experimental investigation focuses on finding optimal parametric data-set of laser micro-drilling operation with minimum taper and Heat-affected zone during laser micro-drilling of Carbon Nanotube/Epoxy-based composite materials. Experiments have been conducted as per Box-Behnken design (BBD) techniques considering cutting speed, lamp current, pulse frequency and air pressure as input process parameters. Then, the relationship between control parameters and output responses is developed using second-order nonlinear regression models. The analysis of variance test has also been performed to check the adequacy of the developed mathematical model. Using the Response Surface Methodology (RSM) and an Accelerated particle swarm optimization (APSO) technique, optimum process parameters are evaluated and compared. Moreover, confirmation tests are conducted with the optimal parameter settings obtained from RSM and APSO and improvement in performance parameter is noticed in each case. The optimal process parameter setting obtained from predictive RSM based APSO techniques are speed=150 (m/s), current=22 (amp), pulse frequency (3 kHz), Air pressure (1 kg/cm²) for Taper and speed=150 (m/s), current=22 (amp), pulse frequency (3 kHz), air pressure (3 kg/cm²) for HAZ. From the confirmatory experimental result, it is observed that the APSO metaheuristic algorithm performs efficiently for optimizing the responses during laser micro-drilling process of nanocomposites both in individual and multi-objective optimization.

• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.309-314
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• 2003

High-efficiency turboblowers in the next generation have been successfully developed and commercialized first in the world, using the high-speed BLDC motors and the foil air bearings. About 20-35% savings in electricity consumption in the field are found in comparison with the conventional roots rotary blowers and the integral gear-driven turboblowers. Current TB75 and TB150 products are replacing the existing blowers in the worldwide market.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.51 no.4
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• pp.219-221
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• 2002

This paper presents an electric scooter development using blushless DC motor. In recent scooters was to develop for sport leisure and short transportation. Most of scooter are used petroleum gas. This gas scooter has disadvantage to pollute the air. Some of scooters have developed by DC motor which require a brush. However brushless motors have higher maximum speed and greater capacity, save maintenance labour and produce less noise. There is also greater freedom in planing the usage of brushless motors. In this paper we develop an electric scooter driving BLDC motor for design smart system and control speed of scooter with current reference signal to apply voltage to motor by means of three phase inverter. Using accelerator device we generate current reference to control speed and send the current to a MICOM by A/D converter. This MICOM produces the voltage signal and hall sensors signal and PWM controller drive three phase inverter to minimize error between the reference and an actual current.

• Journal of Power Electronics
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• v.11 no.4
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• pp.520-526
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• 2011

This paper presents a balanced soft-chopping circuit and a modified PI controller for a high speed 4/2 Switched Reluctance Motor (SRM) with a 16 pulse per revolution encoder. The proposed balanced soft-chopping circuit can supply double the switching frequency in the fixed switching frequency of power devices to reduce current ripple. The modified PI controller uses maximum voltage, back-emf voltage and PI control modes to overcome the over-shoot current due to the time delay effect of current sensing. The maximum voltage mode can supply a fast excitation current with consideration of the hardware time delay. Then the back-emf voltage mode can suppress the current over-shoot with consideration of the feedback signal delay. Finally, the PI control mode can adjust the phase current to a desired value with a fast switching frequency due to the proposed balanced soft-chopping technology.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.5
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• pp.690-697
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• 2012

Novel 8/10 bearingless switched reluctance motor, which can control rotor radial positions with magnetic force, is proposed. The motor has combined characteristics of switched reluctance motor and magnetic bearing. This paper proposes a air-gap control system method of suspending force control in a bearingless switched reluctance motor (BLSRM). The proposed radial force control scheme is independent to the torque winding current. A PI direct current control (DCC) controller and look-up table are used to maintain a constant rotor air-gap. From the analysis and the experimental results, it is shown that the proposed strategy is effective in realizing a naturally decoupled radial force control of BLSRM.

• Transactions of Materials Processing
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• v.24 no.1
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• pp.20-27
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• 2015

Hot tensile tests were conducted at different temperatures ranging from $20^{\circ}C$ to $550^{\circ}C$ to evaluate the mechanical properties of Al5052 seamless tubes. Such tubes can provide the technological foundation for complex forming using hot air bulging. Hot air bulging is one of the recently developed hydroforming techniques and it has some limitations in terms of cycle times. The benefits of hot air bulging are weight and cost savings through part consolidation and reduced post-forming processes such as welding and piercing. In order to extend the forming limits of Al lightweight material hot air bulging was investigated. A heated tube was placed in a heated die and sealed at the ends by sealing cylinders. The heated tube was subsequently expanded against the die cavity wall by internal pressure using air medium. The results of the current study show that axial feeding speed and air pressure have an effect on the formability of Al tubes during air bulging at elevated temperatures.