• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.1
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• pp.76-82
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• 2011

The thrust axis alignment of the launch vehicle is very important because the misalignment causes the unstable attitude control and results in mission failure. Generally, optical methods such as digital theodolite and laser tracker and mechanical method such as turn table method are used to align the thrust axis. This article deals with the simple method using inclinometer based on the gravitational direction. The inclinometer indicates zero degree when that is located on the perpendicular plate to gravitational direction. This method needs two inclinometer, such as standard and alignment ones and uses the angle difference as the reference data to adjust the TVC actuator offset.

• Aerospace Engineering and Technology
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• v.11 no.1
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• pp.158-168
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• 2012

This paper deals with TVC nozzle stroke verification test and corresponding analysis techniques related to kick motor TVC system of KSLV-I second stage. It is shown that the relationship between TVC stroke and potentiometer voltage is revealed via the open-loop stroke verification test, and other major operational parameters including nozzle alignment error, actuation error, neutral position, radius of nozzle rotation, location of nozzle rotation center, angle conversion coefficients, etc. are analyzed via the closed-loop stroke verification test. The TVC stroke verification test results for the first and second flight model of KSLV-I show that all TVC operational parameters of KSLV-I second stage were normally setup for the first and second flight tests.

• Aerospace Engineering and Technology
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• v.12 no.1
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• pp.189-199
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• 2013

This paper summarizes results of second stage attitude control of KSLV-I third flight test. The results show that three axes attitude control at coasting phases of KSLV-I was successfully accomplished by the reaction control system, and pitch and yaw attitude control at thrusting phase where second stage kick motor burns was also normally accomplished by using the thrust vector control system. It is verified that the second stage controller performed successfully for all flight phases regardless of some disturbances due to mass center offset, slag effects, and residual thrust of kick motor. These results may provide an important basis in enhancing domestic technology level of attitude control of launch vehicle.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3092-3094
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• 1999

This paper deals with the gait generation of Biped Walking Robot (IWR-III) to have a continuous walking pattern like human. For this, trajectory planning with the consideration of kick action is done in each walking step, and the coordinate transformation is done for simplifying the kinematics. The trunk moves continuously for all walking time and moves toward Z-axis. Balancing motion is acquired by FDM(Finite Difference Method) during the walking. By combining 4-types of pre-defined steps, multi-step walking is done. Using numerical simulator, dynamic analysis and system stability is confirmed. Walking motion is visualized by 3D-Graphic simulator. As a result, the motion of balancing joints can be reduced by the trunk ahead effect during kick action, and impactless smooth walking is implemented by the experiment.

• Korean Journal of Applied Biomechanics
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• v.23 no.2
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• pp.125-130
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• 2013

Although the electronic body protector has been officially adopted by the World Taekwondo Federation(WTF) in 2006, no scientific information is available about the reliability of its performance. The purpose of this study, therefore, was to investigate the relationship between the impact value of electronic body protector and the impact force of force platform. Male collegiate Taekwondo athletes([MCTA], n=21) and male collegiate Taekwondo students([MCTS], n=20) volunteered to participate in the study. Each subject performed the apchagi, dollyeochagi and dwichagi on the force platform and the electronic body protector. At the apchagi, it showed that MCTS(about 4,700 N) generated more maximum kick force than MCTA(about 3,900 N), but it expressed that MCTA(about 5,300 N) generated more maximum kicking force than MCTS(about 4,400 N) at the dwichagi. At the apchagi and the dwichagi, it indicated the high coefficient of correlation(over r=.8) which supports higher explanation force the relationship between the impact value of electronic body protector and the impact force of force platform, but there was no statistically significant difference at the dollyeochagi.

• Explosives and Blasting
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• v.31 no.1
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• pp.1-10
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• 2013

In blasting demolition, a method would be chosen among many depends on shape and system of a structure and its surround. To demolish using explosives a structure, which is asymmetric and with high aspect ratio, pre-weakening, explosive locations, detonating delay, and surround conditions are needed to be considered in front to design blasting demolition plan. In this study, to over turn asymmetric and high aspect ratio structure in safe, a simulation using a software named Extreme Loadings for Structures, ELS, had performed. In results, it is achieved optimized pre-weakening shapes and locations, which prevent kick back motion of the structure when it collapse, by analyzing moment distribution caused by pre-weakening. And of structural collapse and by minimizing asymmetric structure's torsional moment. Also, after the demolition, simulation results are also compared with actual collapse behavior. In results, it is confirmed the accuracy of collapse behaviour simulation results, and in blasting demolition, kick back motion can be controled by adjusting pre-weakening shape and location, and the torsional moment of an asymmetric structure also can be solved by optimizing detonation locations and its time intervals.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.6 s.348
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• pp.53-61
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• 2006

In high speed flash type or pipelining type A/D Converter, the faster sampling frequency is, the more the effect of DC reference fluctuation is increased by clock feed-through and kick-back. When we measure A/D Converter, further, external noise increases reference voltage fluctuation. Thus reference fluctuation reduction circuit must be needed in high speed A/D converter. Conventional circuit simply uses capacitor but layout area is large and it's not efficient. In this paper, a reference fluctuation reduction circuit using transmission gate is proposed. In order to verify the proposed technique, we designed and manufactured 6bit 2GSPS CMOS A/D converter. The A/D converter is based on 0.18um 1-poly 5-metal N-well CMOS technology, and it consumes 145mW at 1.8V power supply. It occupies chip area of $977um\times1040um$. Experimental result shows that SNDR is 36.25 dB and INL/DNL ${\pm}0.5LSB$ when sampling frequency is 2GHz.

• Korean Journal of Applied Biomechanics
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• v.18 no.3
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• pp.33-42
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• 2008

The purpose of this study was to analyze kinematic variables during Side kick motion in Taekwon Aerobics. The subjects of this study were the 7 skilled and 7 unskilled female college students. A QTM and an Auto Track were used to acquire raw data. The sampling rates camera was 100 Hz. The parameters were calculated and analyzed with Visual3D and SPSS 12.0. The results were as following; 1. In the elapsed time, there was no significance difference statically between a skilled and unskilled group. 2. In the cases of knee angle, there was significant difference statically at Maximum Knee Flexion2(p=0.046, F=4.925). 3. In the cases of knee angular velocity, there was significant difference statically at Maximum Knee Flexion1(p=0.031, F=5.940). 4. In the flexion/extension of hip angle, there was significant difference statically at Maximum Knee Flexion2(p=0.012, F=8.668). 5. In the abduction/adduction of hip angular velocity, there was significant difference statically at Minimum Knee Flexion (p=0.019, F=7.324). 6. In the external rotation/internal rotation of hip angular velocity, there was significant difference statically Minimum Knee Flexion(p=0.005, F=11.87).

• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.4
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• pp.439-444
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• 1986

In this paper the PID-B self-tuner[1] is extended to allow a less abrupt response to set point or plant parameter changes and to control a nonminimum phase plant. The proposed extended PID/ST derived from the direct pole-placement PID/ST is obtained with the Bezout identity as the underlying design method. And its control gains are normalized by the integral control gain. Although the integral control gain is normalized to 1 in our scheme, the so-called "set point and derivative kick" can be avoided sufficiently by normalizing the measurement vector and set point.

• Archives of design research
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• v.16 no.2
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• pp.197-208
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• 2003

A recent trend for product development requires that product design firms participate in every process in cooperations with clients. So, this study proposed an advanced practical management process for product design according to the new trend Because existing processes explain summary steps just including market research, design, engineering, manufacturing., to support the recent trend, an extended process which explains every steps should be prepared. Design development precesses include initial meeting, contact, kick-off meeting, market research, idea sketch, rendering, design drawing, design mock-up, design manual, engineering drawing, ES mock up, mold, manufacturing, and patent. To manage these whole design processes, designers should have abundant knowledge about them. This process has three merits: 1) understanding the whole processes, 2)the unity between design and manufactures, 3)collecting accurate information by market research, 4)elevating design quality. So, designers are able to manage whole product development processes. This practical management process proposes an advanced structure for product design development, and can be accepted for various product design development environments.