• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2008.04a
• /
• pp.561-566
• /
• 2008

Recently, because of development of the high speed train technology, the vibration loads by train is significantly increased ever than before. This buried gas pipelines are exposed to both repeated impact loads, and, moreover, they have been influencing by vibration loads than pipeline which is not located under vehicle loads. The vibration characteristic of pipeline is examined by dynamic analysis, and variable is only train speed. Since an effect of magnitude of vibration loads is more critical than cover depth, as increasing the train speed, the vibration speed of buried pipelines is also increased. The slope of vibration velocity is changed by attenuation of wave, at train speed, 300 km/h. From the analysis results, the vibration velocity of pipelines is satisfied with the vibration velocity criteria which are established by Korea Gas Corporation. The results present operation condition of pipelines under rail loads has fully sound integrity based on KOGAS specification.

• Journal of KSNVE
• /
• v.10 no.2
• /
• pp.221-228
• /
• 2000

In this paper, analytical study is performed to reduce residual vibration in seeking mode of optical pick-up. The conditions for acceleration adn deceleration time in trapezoidal velocity profile to reduce residual vibration are derived for undamped vibration system. To verify the validity of conditiosn two example studies are carried out. Numerical and experimental implementations for flexible arm system attached to moving part show that residual vibration is effectively reduced by calculated velocity profile. In addition, simulation study for optical pick-up reveals that by changing natural frequency to resonance frequency the conditions derived assuming undamped system can be applied to obtain velocity profile for minimum residual energy in damped vibration system.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.13 no.6
• /
• pp.321-328
• /
• 2018

This paper presents an automatic target tracking flight system using a PID controller based on velocity command of a multirotor UAV. The automatic flight system includes marker based onboard target detection and an automatic velocity command generation replacing manual controller. A quad-rotor UAV is equipped with a camera and an image processing computer to detect the marker in real time and to estimate the relative distance from the target. The marker tracking system consists of PID controller and generates velocity command based on the relative distance. The generated velocity command is used as the input of the UAV's original flight controller. The operation of the proposed system was verified through actual flight tests using a marker on top of a moving vehicle and tracks it to successfully demonstrate its capability using a quad-rotor UAV.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2000.11a
• /
• pp.319-326
• /
• 2000

It is investigated character of the dynamic behavior at over excavation zone of roadbed using crushed stone instead of lean concrete. It is considered that behavior of roadbed using PENTAGON-3D and Baber's equation. Typical load of sine wave type using impact factor is compared to moving load system to examine relationship in using PENTAGON-3D case. Variations of this paper are material properties of roadbed, train velocity, subgrade bearing capacity. Using variations, safety of roadbed is estimated by dynamic behavior character.

• 제어로봇시스템학회:학술대회논문집
• /
• 1989.10a
• /
• pp.211-215
• /
• 1989

This paper describes a dynamic robotic assembly system in which an industrial robot executes peg-in-hole task in a moving state. As an effective means to synchronize the end-effector of the robot with the moving conveyor this work uses a control algorithm which is essentially a PID position control scheme combined with velocity feedforward loop. A RCC wrist is used for the inserting task and its force responses are investigated for various tracking conditions and inserting velocities through a series of experiments.

• Proceedings of the KOSOMBE Conference
• /
• v.1992 no.11
• /
• pp.39-42
• /
• 1992

Color Doppler flow mapping (CDFM) was performed on an $\underline{in\;vitro}$ experimental setup with a regurgitant moving orifice using the proximal isovelocity surface area (PISA) technique. PISA flow rates underestimated actual flow rates by as much as 65%, which is very important in diagnosing patients with valvular regurgitations or stenosis. The correction factor considering the velocity of the orifice improved the PISA flow rates.

• Proceedings of the KIEE Conference
• /
• 1998.07a
• /
• pp.113-115
• /
• 1998

This paper presents the indirect boundary integral equation method(BIEM) to analyze 3D moving conductor problem. Instead of an artificial upwind algothm, the proposed method uses a fundamental Green's function which is a particular solution of diffusion equation. Therefore, this method yields a stable and accurate solution regardless of the Peclet number. The indirect BIEM is compared with 3D upwind FEM for a numerical model which has analytic solutions.

• Proceedings of the Korea Institute of Convergence Signal Processing
• /
• 2003.06a
• /
• pp.82-85
• /
• 2003

This paper proposes a preprocessing method for tracking aircraft's take-off and lading. The method uses accumulative difference image technique for segmenting the object from the background, and obtains the centroid of the object exactly using centroid method. Then the moving object is analyzed and represented with the information such as feature point, velocity, and distance. A simulation result reveals that the proposed algorithm has good performance in segmenting and tracking the aircraft.

• Reproductive and Developmental Biology
• /
• v.38 no.3
• /
• pp.107-114
• /
• 2014

Oral exposure of humans by excess amounts of arsenic may cause disturbances of the reproductive system. In the present study, such exposure was modelled in rats, with the support of sperm principal parameters and histopathological observations. Male Sprague-Dawley rats were randomly divided into three groups where the group I was served as a normal control, group II was received sodium meta-arsenite as arsenic (10 mg/kg b.w/day) and a combination of sodium meta-arsenite and sodium selenite (3 mg/kg b.w/day) in group III. After 6 weeks, there was no significant change in testis weight and in total motility of all the three experimental groups, whereas, rapid moving spermatozoa, moderately moving spermatozoa and slow moving spermatozoa were significantly decreased in arsenic treated rats as compared to control rats. The other sperm principal parameters like progressiveness, average path velocity, straightness linear velocity (VSL), curvilinear velocity (VCL), straightness, linearity sperm head elongation ratio, area, linearity amplitude of lateral head department (ALH) and beat cross frequency (BCF) were found to be reduced in arsenic intoxicated rats. These results are not correlated with the histological studies. On oral administration of selenium ameliorated the adverse effects of arsenic as compared to arsenic alone treated rats. Our findings clearly demonstrate that administration of selenium could prevent some of the deleterious effects of arsenic in the testis.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.28 no.6
• /
• pp.459-469
• /
• 2017

An air-to-ground guidance missile aimed to hit a main battle tank(MBT) should detect a ground moving target and estimate the target position to guide. In this paper, we detect a front ground moving target by using FMCW(Frequency Modulated Continuous Wave) and estimate the position by forward-looking SAR(Synthetic Aperture Radar) via scanning certain front ground section by steering a beam with narrow beamwidth left to right mechanically. Also, by MLE(Maximum Likelihood Estimation), degree of how fast the target approach or recede from the radar can be figured out from the estimated radial velocity of the moving target. Subsequently, we generate a radar image via corrected matched filter from phase history including the radial velocity.