• Journal of Power System Engineering
• /
• v.8 no.3
• /
• pp.58-66
• /
• 2004

The sway motion control problem of a container hanging on the trolly is considered in the paper. In the container crane control problem, suppressing the residual swing motion of the container at the end of acceleration, deceleration or the case of that the unexpected disturbance input exists is main issue. For this problem, in general, many trolley motion control strategies are introduced and applied. In this paper, we introduce and synthesize a swing motion control system in which a small auxiliary mass is installed on the spreader made by ourselves. In this control system, the actuator reacting against the auxiliary mass applies inertial control forces to the container to reduce the swing motion in the desired manner. Especially, we apply the $H_{\infty}$ based gain-scheduling control technique the anti-sway control system design problem of the controlled plant. In this control system, the controller dynamics are adjusted in real-time according to time-varying plant parameters. And the simulation result shows that the proposed control strategy is shown to be useful to the case of time-varying system and, robust to disturbances like winds and initial sway motion.

• Proceedings of the KSME Conference
• /
• 2004.11a
• /
• pp.631-636
• /
• 2004

The sway motion control problem of a container hanging on the trolly is considered in the paper. In the container crane control problem, suppressing the residual swing motion of the container at the end of acceleration, deceleration or the case of that the unexpected disturbance input exists is main issue. For this problem, in general, many trolley motion control strategies are introduced and applied. In this paper, we introduce and synthesize a swing motion control system in which a small auxiliary mass is installed on the spreader made by ourselves. In this control system, the actuator reacting against the auxiliary mass applies inertial control forces to the container to reduce the swing motion in the desired manner. Especially, we apply the $H_{\infty}$ based gain-scheduling control technique the anti-sway control system design problem of the controlled plant. In this control system, the controller dynamics are adjusted in real-time according to time-varying plant parameters. And the experiment result shows that the proposed control strategy is shown to be useful to the case of time-varying system and, robust to disturbances like winds and initial sway motion.

• Explosives and Blasting
• /
• v.28 no.1
• /
• pp.40-54
• /
• 2010

The messer shield method applys mainly to a tunnel with small cross-section of a weathered soil or weathered rock district and is fulfilled mostly by man-power excavation. but in case that hard rock exposes on tunnel face, incredible is an application of the rock-splitting method using a hydraulic power or a blasting method. This study represents the case of a blasting method which can control to be practiced by the minimum charges of 125 g an initial vibration occurring at the cut instead of the rock-splitting method, even though water pipe and gas pipe are closely adjacent.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.5 no.2
• /
• pp.29-37
• /
• 2009

Recently, the structure of simulation environment is important issue in all fields. In case of the training for operating the machines which are costly such as airplanes or spaceships, simulators could be helpful for decreasing the costs and training effects by simulating real situation. When we get the driving license, too many peoples are waiting for their turns because of limited cars and testing spaces in Korea. To solve this problem, we've designed and developed the basic design for the simulators. We suggested the Computer 3D Simulation Model for practice of a drives's license. The concept of this simulator was from a 3D Racing-game which suit for driving exercise. We provide users with handle-controlled simulation setting in order that users feel reality as if they drive really through this simulator. We also use 'force-feedback' system which give handle vibration in case users collide against obstacles or exceed the line since users can absorb the simulation program and feel the sense for the real. This paper is the study about modeling the driving exercise model made use of 'computer 3D simulation', and producing and utilizing the simulator through this modeling.

• Journal of the Korean Society for Precision Engineering
• /
• v.18 no.7
• /
• pp.53-64
• /
• 2001

The gain-scheduling control technique is vary useful in the control problem incorporating time varying parameters which can be measured in real time. Based on these facts, in this paper the sway control problem of the pendulum motion of a container hanging on the trolly, which transports containers from a container ship to trucks, is considered. In the container crane control problem, suppressing the residual swing motion of the container at the end of acceleration, deceleration or the case of that the unexpected disturbance input exists is main issue. For this problem, in general, the trolley motion control strategy is introduced and applied. But, in this paper, we introduce and synthesize a new type of swing motion control system. In this control system, a small auxiliary mass is installed on the spreader. And the actuator reacts against the auxiliary mass, applying inertial control forces to the container to reduce the swing motion in the desired manner. In this paper, we assume that an plant parameter is varying and apply the gain-scheduling control technique design the anti-swing motion control system for the controlled plant. In this control system, the controller dynamics are adjusted in real-time according to time-varying plant parameters. And the simulation result shows that the proposed control strategy is shown to be useful to the case of time-varying system and, robust to disturbances like winds and initial sway motion.

• Journal of Korean Foot and Ankle Society
• /
• v.19 no.2
• /
• pp.73-76
• /
• 2015

The calcaneal insufficiency avulsion fracture usually occurs in an area of fused apophysis in adults without significant history of trauma or overuse activities. It is an uncommon injury which has been described in patients with complicated diabetes, Charcot neuroarthropathy, amyloidosis with neuropathy, severe osteoporosis, and other conditions. Discussion of the issue of fracture location is still not sufficient. We report on a case of a 50-year-old male who experienced a non-traumatic diabetic calcaneal insufficiency fracture. Intraoperatively, a biopsy specimen was obtained from the exposed fracture site for histological study. We assume that the calcaneal fused apophyseal line is the weak point of failure due to various incomplete mixtures of trabecular bone, woven bone, and cartilaginous tissues, and may fail when repeated tensile stress is imposed.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.40 no.2
• /
• pp.112-122
• /
• 1998

Measurement of electrical resistivity in soils has been used for many years with purpose of estimating in situ porosity or density. Recently electrical resistivity has also been used as an indicator of soil contaimination. This paper presents the result of laboratory experiment to investigate the resistivity variation in contaminated sandy soils. The results can be used with the Cone Penetrometer Test (CPT) result to analyse ground condition. In the experiment, the water content and leachate concentration of soils were controlled by groundwater and leachate, and then the resistivity measurement was made with 'STING-R1' by Advanced Geosciences Inc. In the case of using groundwater, the resistivity was in the range of over 1000${\omega}{\cdot}m$, but in the case of using polluted water by leachate, the resistivity decreased significantly down to 10~ 100${\omega}{\cdot}m$ for the same moisture content. Also the resistivity varied according to the degree of saturatrion. Therefore, if soil is contaminated by leachate, the CPT with electrical resistivity sensor might be used to investigate the contamination status and plume migration. But exact component of leachate and the pollutant concentration are still hard to identify.

• Journal of the Korea Computer Industry Society
• /
• v.6 no.5
• /
• pp.821-828
• /
• 2005

This paper was proposed Intelligent and wireless USN/RFID module system that can overcome disadvantage of existing RFID system with no sensing module and wire communication. The proposed USN/RFID system was designed and fabricated. After fabricating new system, we analyzed the characteristics of USN/RFID module. After design VCO block that is point circuit to develop next generation system one chip of RFID system. we were carried out simulation and verified the validity, this paper was showed that VCO system was enough usable in wireless network module. USN/RFID Reader module shows superior result that validity awareness distance corresponds to 30M in the case of USN and to 5M in RFID Reader's case and 900MHz of commercial frequency does practical use enoughly in range of high frequency. The USN/RFID Reader module is considered to act big role to Ubiqitous industry offering computing surrounding of new concept that is intelligence type service and that was associated to real time location system(RTLS). environment improvement/supervision. national defense, traffic administration etc.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.3 no.1
• /
• pp.207-217
• /
• 2000

A fire fighting characteristic by a single evaporating droplet in the case of a fire of military enclosure space was studied experimentally. Transient cooling of solid surface by water droplet evaporation has been investigated through controlled experiments using a heated brass cylinder. Quantitative predictions of droplet evaporation time and in-depth transient temperature distribution in solid have been made. The particular interest was in the removal of thermal energy from the heated cylinder by evaporative cooling. A $10{\mu}1$ single droplet is deposited on a horizontal brass surface with initial temperatures in the range of $90^{\circ}C{\sim}130^{\circ}C.$ The results can be summarized as follows; Evaporating droplet was divided into three different configuration. Evaporation time was predicted as a function of initial surface temperature ($t_c=492.62-6.89T_{s0}+0.0248T_{s0}^2).$ The contact temperature was predicted as a function of initial surface temperature( $T_{i}$=0.94 $T_{s0}$+1.4), The parameter ${\beta}_o$ was predicted as a function of initial surface temperature( ${\beta}_0$ : 0.O0312 $T_{s0}+0.932$)>)>)

• Journal of Advanced Marine Engineering and Technology
• /
• v.30 no.5
• /
• pp.623-628
• /
• 2006

Laser material processing is a very fast advancing technology for various industrial applications. because of many advantages. Its major advantage of less and controlled heat input has been exploited successfully for the very critical application of aluminium alloy welding. This study suggested the occurrence source of weld-defects and its solution methods in a welding of lithium ion battery by pulsed Nd:YAG laser. In experiment. battery case has changed over joint geometry from welding of side position to flat one. In the case of a electrolyte injection hole in order to seal it. welding is carried out after pressing Al ball. At this time. an eccentric degree. contact length and gap are worked as a major parameters. As improving the method of Al ball pressing. it was able to reduce an eccentricity. increase the contact length and decrease gap. As a results of a experiment. a sound weld bead shape and crack-free weld bead can be obtained.