• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1313-1317
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• 2005

This paper presents the overall design, manufacture, and test result of the high capacity (more than 150 Am^2) magnetic torquer for the use of satellite control. To provide an electrical current to the magnetic torquer, the driving electronics is also constructed. The integration and test of the magnetic torquer and its driving electronics are performed via the magnetic field measurement according to the distance and the magnetic torque measurement with torque-meter. To compare the performance obtained from the test results we also perform computer simulation with three-dimensional model.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.431-432
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• 2006

In this study, the effect of the temperature of magnesium slurry was investigated by mechanical stirring method. The evaluations of rheological behavior of AM50A magnesium alloy were measuring of viscosity and microstructures in the semisolid state. The apparent viscosity was investigated at continuous cooling rate using a concentric cylinder viscometer. Measurement of viscosity measures torque that act to stirrer rotating in slurry doing continuous cooling using torque-meter and expressed by POWER-LAW. Microstructures were observed after mechanical stirring that enforce time at steady state temperature of solid fraction.

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.108-110
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• 1999

In this paper, approximate means of estimating the flux and torque levels in an induction motor is discussed. There exists several method that is used directly by flux meter and flux sensing coils in the airgap. Most of these methods are sensitive to motor parameter value changes. Also, the harmonics in the motor voltage and current due to the nonsinusodial inverter waveform cause errors in the estimated torque. Finally, this result is applicated in arch type linear induction motor for study of noise and vibration.

• Journal of the Korean Society for Railway
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• v.2 no.1
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• pp.56-66
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• 1999

This purpose of this paper is to perform the readhesion control algorithm of the urban railway traction. A study on readhesion control algorithm is done for the adhesion system. This system has all characteristics of the voltage source converter by a process ability to regenerate power. The traction motor is controlled by IGBT inverter. The test equipment composes traction motor, torque-meter, clutch, and a tubular type of interia mass.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.891-893
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• 2003

This paper Presents the optimum design of Brushless DC Motor using multi-objective function Neural Network to maximize efficiency and Ratio of Torque Per unit weight.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.4
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• pp.437-442
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• 2015

The swirl ratio in a SI engine is investigated in a steady flow bench according to the measurement methods: an impulse swirl meter and particle image velocimetry (PIV). When measuring the swirl ratio using the PIV, the torque is evaluated based on the cylinder center and swirl center, respectively. The position of the measurement plane is considered. As a result, in the upstream, the swirl ratio measured by the impulse swirl meter is estimated to be larger than that from the PIV measurements due to the unstable vortex motions. Regarding the PIV measurements, the swirl ratio based on the cylinder center has been found to be lower than that based on the swirl center. On the other hand, the difference in swirl ratio has decreased smaller as the measurement plane moved downstream due to the stabilization of the vortex motion.

• Journal of Korean Neurosurgical Society
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• v.53 no.5
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• pp.288-292
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• 2013

Objective : Vertebral distraction is routinely performed during anterior cervical discectomy and fusion (ACDF). Overdistraction can injure the facet joints and may cause postoperative neck pain consequently. The purpose of this study was to investigate the clinical relevance of distraction force during ACDF. Methods : This study included 24 consecutive patients with single level cervical disc disease undergoing single level ACDF. We measure the maximum torque just before the the arm of the Caspar retractor was suspended by the rachet mechanism by turning the lever on the movable arm using a torque meter. In order to turn the lever using the torque driver, we made a linear groove on the top of the lever. We compared the neck disability index (NDI) and visual analogue scale (VAS) scores between the high torque group (distraction force>6 $kgf{\cdot}cm$) and the low torque group (distraction force${\leq}6kgf{\cdot}cm$) at routine postoperative intervals of 1, 3, 5 days and 1, 3, 6 months. Results : The VAS scores for posterior neck pain had a linear correlation with torque at postoperative 1st and 3rd days ($y=0.99{\times}-1.1$, $r^2=0.82$; $y=0.77{\times}-0.63$, $r^2=0.73$, respectively). VAS scores for posterior neck pain were lower in the low torque group than in the high torque group on both 1 and 3 days postoperatively ($3.1{\pm}1.3$, $2.6{\pm}1.0$ compared with $6.0{\pm}0.6$, $4.9{\pm}0.8$, p<0.01). However, the difference in NDI scores was not statistically significant in all postoperative periods. Conclusion : Vertebral distraction may cause posterior neck pain in the immediate postoperative days. We recommend not to distract the intervertebral disc space excessively with a force of more than 6.0 $kgf{\cdot}cm$.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.899-905
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• 2000

The characteristics of air flow and engine performance with swirl ratio variance of intake port In a turbocharged DI diesel engine was studied in this paper. The intake port flow is important factor which have influence on the engine performance and exhaust emission because the properties in the injected fuel depend on the combustion characteristics. The swirl ratio for ports was modified by hand-working and measured by impulse swirl meter. For the effects on performance and emission, the brake torque and brake specific fuel consumption were measured by engine dynamometer and NOx, smoke were measured by gas analyzer and smoke meter. As a result of steady flow test, when the valve eccentricity ratio are closed to cylinder wall, the flow coefficient and swirl intensity are increased. And as the swirl ratio is increased, the mean flow coefficient is decreasing, whereas the gulf factor is increasing. Also, through engine test its can be expected to meet performance and emission by optimizing the main parameters; the swirl ratio of intake port, injection timing and compression ratio.

• The KSFM Journal of Fluid Machinery
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• v.20 no.2
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• pp.47-52
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• 2017

In general industry, TFM(turbine flow meters) as measuring instruments having high reliability are widely used in the trade of petroleum and in the measurement of tap water and hot water. The TFM is performed calibration for using in the field and is mainly calibrated at room temperature. Since accuracy of TFM depends on Reynolds number of fluid, TFM is calibrated at same Reynolds number by changing flow rate. Furthermore, the TFM using a fluid of high temperature should have considered for other factors such as the thermal expansion of the parts and characteristics change is unknown changes in the turbine flow meter accordingly. In this paper, two turbine flowmeter are experimentally studied about characteristics change using the facilities which can change fluid temperature from 6 degree celsius to 90 degree celsius. As a result, the turbine flow meter can be calibrated to minimize the error characteristic at a similar temperature and the actual temperature.

• Journal of Power System Engineering
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• v.12 no.3
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• pp.38-43
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• 2008

The usage of electric forklift truck is gradually increasing due to the convenience at conveying and arranging the materials in the industrial field. In this study, the author designed and suggested the optimum driving system and load tester which both of them are the most important part of the forklift truck. The planetary gear is chose to driving system because it makes big power even though the motor size is small. The gear teeth of planetary gear were designed and the designed planetary gear was tested considering the yield strength and the abrasion of gear teeth. The B-Type electric brake which consists of multiple plates and operates with non-magnetic type was connected with a single shaft in the driving system. So, it can be applied at the sudden braking situation which has the torque increment. And it has the compact size and excellent durability Load tester can give the various levels of load to the planetary gear of driving system in the electric forklift truck and it can also measure the levels of the load which were applied. Therefore, we can measure the noise, torque and perform the durability, vibration tests using load tester. It will be economical because many kinds of test can be performed using reasonable priced load tester The driving system of electric forklift truck which has sufficient competitive can be manufactured using our designed planetary gear reducer with reasonable price. The designed load tester can use for checking the performance of other reducers, as well.