• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.7
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• pp.891-899
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• 1997

This paper presents the results of a detailed experimental examination of fully developed asymmetric flows between annular tubes with square-ribbed surface roughness. The main emphasis of the research has been on establishing the turbulence structure, particularly in the central region of the channel where the two dissimilar wall flows interact. Measurements have included profiles of time mean velocities, turbulence intensities, turbulent shear stresses, triple velocity correlations, skewness, and flatness. The region of greatest interaction is characterized by strong diffusional transport of turbulent shear stress and kinetic energy from rough toward the smooth wall region, giving rise to an appreciable separation between the planes of zero shear stresses depending on positions of roughness on the walls.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.3
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• pp.398-404
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• 2013

The simulation of the ballistic trajectory of penetrator into the spaced multi-layer RC targets is very important to predict the hitting condition in subsequent target. Because of perturbation by lateral load of penetrator caused by asymmetric hitting position between penetrator and steel bar reinforcement, penetrator rotates and deviates from the straight path. Therefore, penetration capability of penetrator is decreased in the subsequent targets. This paper presents the result of the penetration of steel-bar-reinforced concrete target by using the explicit finite element code LS-DYNA. A series of computations is performed and compared to experimental data and the computed results are in good agreement with the experimental results over a wide range of velocities. And then we conduct the simulation according to various RC target hitting condition and impact velocities.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.3
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• pp.404-412
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• 2008

As a suitable volute configuration in the range of low specific speed, circular casing is suggested in this study. The internal flows in a centrifugal pump with the circular and spiral casings are measured by PIV and analyzed by CFD. The results show that the head and efficiency of the pump by a circular casing of very small radius are almost same as those by the spiral casing. Even at the best efficiency point, the internal flow of the pump by circular casing is asymmetric, and vortex and strong secondary flow occurs in the impeller passage. The radial velocity becomes higher remarkably only near the region of the discharge throat. The flow in the impeller outlet is strongly controlled by the circular casing because the velocity distribution almost does not affected by the position of the impeller blades.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.8
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• pp.1519-1525
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• 2009

This paper presents a novel passive converter for single phase SRM. The proposed passive converter has additional passive power circuit which is consisted by three diodes and one capacitor in the front-end of conventional asymmetric converter to supply a high negative bias during demagnetization. The high negative bias can reduce the demagnetization time and negative torque from tail current in single phase SRM. So, It can extend positive torque region by the extended turn-off position. In this paper, the structure and operating modes of a novel passive converter are introduced with mathematical model. The proposed single phase SRM using passive converter is verified by the computer simulation and experimental results.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.922-925
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• 2004

The paper presents the component parts and their models of the Switched Reluctance motor drive system with the angle position-current chopping control and with the fixed angle pulse width modulation control. The calculation of the parameters and the simulated models based on the MATLAB SIMULINK software package are introduced by a four-phase 8/6 structure prototype with the four-phase asymmetric bridge power converter. The simulation of the prototype in the course of starting is made by the simulated models at the different control strategies and the different given rotor speed.

• Journal of International Academy of Physical Therapy Research
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• v.2 no.2
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• pp.294-300
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• 2011

The purpose of this study was to investigate the influence of the static pelvic inclination and declination in the static standing position on weight bearing rate and gait elements. Fourteen healthy adults in their twenties were participated. Two groups of healthy adults were allocated in this study: above and below the average of pelvic tilt. The correlation between the pelvic inclination, weight bearing rate and gait elements were measured. There was a statistical correlation between the pelvic tilt and step. Also, there was a statistical difference when we compared anterior declination with swing period and posterior declination with step. There was an asymmetric correlation between pelvic tilt and step. However, there was no statistical difference between the groups above and below the average of pelvic tilt. This result indicates that dipper pelvic inclination doesn't affect the asymmetry of step.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.1
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• pp.40-44
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• 2013

This paper presents a design and characteristics analysis of novel 2-phase 4/3 switched reluctance motor (SRM) with short flux path for an air-blower application. The desired air-blower is unidirectional application, and requires a wide positive torque region without torque dead-zone. In order to get a wide positive torque region without torque dead-zone during phase commutation, asymmetric inductance characteristic with non-uniform air-gap is considered. The proposed motor could be started at any rotor position with high efficiency drive. The proposed 2-phase 4/3 SRM is verified by finite element method analysis.

• Journal of the Korea Society of Computer and Information
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• v.23 no.3
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• pp.33-40
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• 2018

In this paper, we propose a method to effectively split the adjacent baggage that is moving on high speed conveyor of airport. The proposed method calculate the Angle Histogram(AH) that inspects background pixels within radius r based on the center point of the adjacent baggage. After that, the adjacent baggage is segmented by finding split angles at the AH. We also improved the split quality of adjoining baggage by repeatedly correcting the center point to correctly split adjacent baggage of asymmetric size. And the calculation time of AH is reduced about 1/3 by using the symmetry property of the circle. Experiments have shown that 93% of all adjacent baggage images are correctly segmented and the proposed method is effective.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.403-406
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• 2002

The paper presents the componet parts and their models for the switched reluctance motor drive system with the angle position-current chopping control and with the fixed angle pulse width modulation control. The calculation of the parameters and the simulated models based on the MATHLAB SIMULINK software package are introduced by a four-phase 8/6 structure prototype with the four-phase asymmetric bridge ower converter. The simulation of the prototype in the course of starting is made by the simulated models at the different control strategies and speeds.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.7
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• pp.40-50
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• 1996

An unified compliant control algorithm to regulate the force by dual arms is proposed, where tow arms are treated as one arm in a kinematic viewpoint. The force error calculated form the information of two force/torque sensors attached to the end of each arm is transferred to minimum actuator coordinates, and then is distributed to total system actuator coordinates. The position adjustment at the total actuator coordinates is computed based on the effective computed based on the effective compliance matrix with respect to total actuator coordinates, which is obtained by coordinate transformation between the task coordinates and the total actuator coordinates. An experiment is carried out for dual arms with asymmetric kinematic structure to control an interaction force between manipulators and the environment. The performances of the proposed control algorithm are experimentally compared to those of dual arms employing master/slave scheme. The proposed compliant control algorithm not only ouperforms other algorithms, but also can be treated as an unified approach n the sense that it can be applied to arbitrary dual arm systems with general kinematic structures.