• Journal of the Korean Society of Visualization
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• v.9 no.2
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• pp.40-47
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• 2011

Tilt-rotor aircraft can be used in various fields because they have the capabilities of the vertical take-off and landing and the high-speed cruise flight. In the present study, the flow analysis of a tilt-rotor aircraft is conducted at various tilt angles. The lift and drag forces of the tilt-rotor aircraft are obtained and the wakes by the rotor-blade are visualized. The result shows that the rotor-blade affects the lift force in a hovering mode and the main wing has an influence on the lift force in a cruise mode. Additional thrust is required at the tilt angle of around 40 degree due to the least lift force. The drag force is dependent on the rotor-blade at overall tilt angles. The minus drag force appears between the tilt angles of 90 degree and 55 degree. Also, the drag force is dramatically increased at the other tilt angles. The wake by rotor-blade affects the flow around the fuselage of the tilt-rotor aircraft at the tilt angles of 75 degree and 60 degree.

• Journal of Korean Physical Therapy Science
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• v.18 no.4
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• pp.73-79
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• 2011

Purpose : This study is to know how position change in high-heels affects sacral tilt angle. 15 healthy women aged 21.87(standard deviation=3.54) were tested. Method : Lumbar and sacral tilt angle was measured by radiography barefooted, and after 15 mins of application time, they were measured in the same way in high-heels. Result : There was not notable difference in lumbar lordosis, lumbosacral angle, and sacral tilt angle. However, there was differences in change degree, which was measured by estimation data of [post-pre)/pre]${\times}$100. Conclusion : There was no notable difference in lumbar lordosis, lumbosacral angle, and sacral tilt angle, but as there were differences in change degree, research about how women's lumbar change when heel height increases is needed.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.2
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• pp.192-198
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• 2013

This paper presents the stabilization and design of a pan-tilt control part for the directional pan-tilt system for shipboard directional equipment. In order to control each control axis with compensation for ship motion, the 2 degree of freedom(2DOF) PID controller is designed and its parameters are tuned using a real-coded genetic algorithm(RCGA). Simulation demonstrates the effectiveness of the 2 DOF PID controller tuning.

• Transactions on Electrical and Electronic Materials
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• v.9 no.3
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• pp.120-122
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• 2008

We have studied the tilt angle generation on the homeotropic polyimide (PI) surface using a low intensity ion beam source as a function of incident angle. An excellent LC alignment of nematic liquid crystal (NLC) on the PI surface with ion beam exposure for all incident angles was observed. The tilt angle of NLC on the homeotropic PI surface for all incident angles was from 90 to 88 degree was observed. Also the tilt angle of NLC on the homeotropic PI surface with ion beam exposure of 400 eV had a tendency to increase as ion beam energy incident angle become more instance from 45 degree. Finally, a good LC alignment thermal stability on the homeotropic PI surface with ion beam exposure can be achieved.

• Journal of the Korean Solar Energy Society
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• v.31 no.5
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• pp.27-32
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• 2011

Most of domestic building generally don't have fixed shading devices considering of appearance and aesthetic issues. In this study is suggested that tilt window simultaneously has a role of shading and blocking solar radiation. The tilt window thermal performance is investigated by relation ship between inclination and heating cooling road. As comparing vertical window with $5^{\circ}$ and $7^{\circ}$ of tilt window respectively, the heating load is increased by 3.6% and cooling load is reduced by 8.1% on $5^{\circ}$ tilt window and the heating load is increased by 5.3% and cooling load is reduced by 11.5% on $5^{\circ}$ tilt window. Especially, the total load of alternative tilt window is showed the reduction rate 2.6% and3.6% compared of vertical window. Therefore, the tilt window is possible to role of shading of solar radiation and reduction of heating and cooling load.

• Solar Energy
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• v.19 no.3
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• pp.85-91
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• 1999

This study represented experimental research on the flat-plate solar collector. The heat performances were measured the tube array surface temperature by thermal-couple. The solar collector($W{\times}H$) of $580{\times}1100$, various tilt angles of 30, 45, 60 degree and the internal tube number of 4, 6, 8, 10(ea) were utilized in the present investigation. It is found that the thermal concentration is higher as the tilt angle become larger and the solar tubes are more and more. In this stuby obtained results of following: The array of tubes in collector has the best nice in that the number of tube is eight and the tilt angle is 60 degree. The collect energy by each tube array shown high value by increase the number of tubes and tilt angles. In addition to, the collect energy depends on by the tilt angle than the number of tube.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.2
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• pp.107-117
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• 1998

As the traffic congestion and parking problems in urban areas are increased the tall and narrow commuter vehicles have interested as a means to increase the utilization of existing freewa- ys and parking facilities. However, in hard cornering those vehicles could reduce stability against overturning compared to conventional vehicles. This tendency can be mitigated by tilting the body toward the inside of the turn. In this paper those tilting vehicles are considered in which at speed at least, the tilt angle is controlled by steering the front wheels. In other word, if the driver turns the steering wheel the tilt controller automatically steers the road wheel to tilt the body inside of the turn. Also, the dynamic tilting vehicle model with tire slip angles is constructed by adding the roll degree of freedom. Finally, through computer simulation the behaviors of the tilting vehicles are investigated.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.568-570
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• 2004

This paper presents a study of a position finding system using PSD Sensor and Pan/Tilt. The position of PSD(Position Sensitive Detector) sensor is calculated by the degree of pan-tilt and the difference in height between pan-tilt and PSD. For that, the DSP which control pan-tilt is used for precise operation. The PIC microcontroller process PSD sensor data that indicate light incident position. A user using computer can acquire the conditions of pan-tilt and PSD and issue an order.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.368-372
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• 2002

Since rolling (Radial AC Tilt) motion in Optical Pickup Actuator causes RF signal degradation, many researches have been done to find out how to reduce rolling degree. This paper aims to introduce two methods of reducing rolling degree with their theoretical concepts and experimental results. First method rearranges magnetic circuit and the other one adjusts the proportion of the distances among mass center, actuating center and supporting center.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.389-392
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• 2011

In this study, the engine performance data was extracted and analyzed through the flight test of Smart UAV which is tilt rotor aircraft. The flight test was conducted for the transition flight regime where the tilt angle of prop-rotor varies from 90 degree to 0 degree and vice versa. The engine performance data such as engine power and specific fuel consumption gathered from flight tests were compared well with the results of engine performance analysis program.