• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.161-161
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• 2000

The clean mobile robot for wafer transfer is AGV that carry each wafer to each equipment. It has wafer handling technology, wafer ID recognition technology, position calibration technology using vision system, and anti-vibration technology. Wafer loading/unloading working accuracy is within ${\pm}$1mm, ${\pm}$3$^{\circ}$. By application of this AGV, we can reduce the manufacturing tack time and bring cost down of equipment.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.6
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• pp.869-876
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• 1994

This paper presents an efficient method to calculate voltage collapse point and to avoid voltage instability. To evaluate voltage stability in power systems, it is necessary to get critical loading points. For this purpose, this paper uses linear programming to calculate efficiently voltage collapse point. Also, if index value becomes larger than given threshold value, voltage stability is improved by compensation of reactive power at selected bus. This algorithm is verified by simulation on the IEEE 14-bus sample system.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.2
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• pp.168-177
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• 1998

The effects of the regeneration parameters such as inlet gas temperature, space velocity, oxygen concentration of the exhaust gas, and initial particulate loading on the oxidation of the particulate inside ceramic cordierite filter have been investigated through an engine experiment. As the inlet gas temperature increases, the remarkable filter temperature occurs owing to the rapid combustion rate. Though the higher space velocity affirms the safe regeneration, it also requires much fuel consumption of the burner. For that reason, the space velocity should be compromised considering the fuel economy. The excessive accumulation of the particulate may cause undesirable regeneration temperatures inside filer even under the optimized regeneration condition. The inlet gas temperature should be selected to overcome the variation of the oxygen concentration which is inherent feature of the diesel engine. It is the most important factor in the regeneration control techniques.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.05a
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• pp.255-258
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• 2002

Dental chewing masticator, which is an essential device for evaluating the wear of dental resin and the interfacial failure between the filling resin and enamel of tooth used in conservative dentistry, was developed. This dental chewing masticator mimics the chewing motion and loading by adapting DC motor and rotary cam system. Chewing loading of 49N was imposed by computer-displacement control, loadcell, LM guide, and spring system. Extracted tooth was fixed into a holding jig, and this jig was mounted with rubber pad on the $15^{\circ}$inclined surface to consider the lateral movement of periodontal ligament. A water bath was installed for providing the environment of inside mouth and for circulating the $5^{\circ}C-55^{\circ}C$ water to evaluate the effect of hydrothermal cycling on the damage of resin filled teeth during long-term chewing activity.

• Journal of Environmental Health Sciences
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• v.35 no.5
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• pp.365-375
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• 2009

Agriculture reservoirs need a systematic approach that can control water purity and water improvement. The area under study, Bunam Lake exceeds the agricultural water standard level due to contamination from the upper stream. When the Taean Enterprise City was planned, the water quality improvement plan was applied to minimize the environmental change. However, in order to continuously maintain the water quality in the Bunam Lake, it was essential to apply the Total Pollution Load Management System (TPLMs). In order to achieve the targeted water quality in the Bunam Lake, standard flow rates and targeted water quality levels were applied to obtain the loading capacity which is as follows : BOD 1,891.2 kg/d, T-N 1,945.7 kg/d, T-P 131.7 kg/d. Also, the regional development load was calculated as, BOD 1,083.6 kg/d, T-N 942.2 kg/d, T-P 61.8 kg/d, which is required to be deceased :- by BOD 378.4 kg/d, T-N 198.9 kg/d, T-P 31.6 kg/d in order to safely achieve the targeted water quality in the Bunam Lake.

• Bulletin of the Korean Chemical Society
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• v.28 no.3
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• pp.397-402
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• 2007

Restenosis after percutaneous coronary intervention (PCI) continues to be a serious problem in clinical cardiology. To solve this problem, drug eluting stents (DES) with antiproliferative agents have been developed. Variable local drug delivery systems in the context of stenting require the development of stent manufacture, drug pharmacology and coating technology. We have worked on a system that integrates electrophoretic deposition (EPD) technology with the polymeric nanoparticles in DES for local drug delivery and a controlled release system. The surface morphology and drug loading amount of DES by EPD have been investigated under different operational conditions, such as operation time, voltage and the composition of media. We prepared poly-D,L-lactide-co-glycolic acid (PLGA) nanoparticles embedded with curcumin, which was done by a modified spontaneous emulsification method and used polyacrylic acid (PAA) as a surfactant because its carboxylic group contribute negative charge to the surface of CPNPs (?53.5 ± 5.8 mV). In the process of ‘trial and error' endeavors, we found that it is easy to control the drug loading amount deposited onto the stent while keeping uniform surface morphology. Accordingly, stent coating by EPD has a wide application to the modification of DES using various kinds of nanoparticles and drugs.

• International Journal of Concrete Structures and Materials
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• v.11 no.2
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• pp.377-389
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• 2017

Tests of the lateral and torsional stability are quite sensitive to the experimental conditions, such as support conditions and loading system. Controlling all of these conditions in a full-size test is a very challenging task. Therefore, in this paper, an experimental measurement method that can control the experimental conditions using a small-scale model was proposed to evaluate the lateral and torsional stability of beams. For this, a loading system was provided to maintain the vertical direction of the load applied to the beam, and a support frame was produced to satisfy the in-plane and out-of-plane support conditions. The experimental method using a small-scale model was applied successively to the lateral and torsional behavior and stability of I-shaped beams. The proposed experimental methods, which effectively accommodate the changes in the geometry and length of the beam, could contribute to further experimental studies regarding the lateral and torsional stability of flexural members.

• Smart Structures and Systems
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• v.17 no.5
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• pp.691-708
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• 2016

Recently, number of smart material are investigated and widely used in civil construction and other industries. Present study investigates the application of smart semi-active piezoelectric friction damper (PFD) made with piezoelectric material for the seismic control of the horizontally curved bridge isolated with lead rubber bearing (LRB). The main aim of the study is to investigate the effectiveness of hybrid system and to find out the optimum parameters of PFD for seismic control of the curved bridge. The selected curved bridge is a continuous three-span concrete box girder supported on pier and rigid abutment. The PFD is located between the deck and abutments or piers in chord and radial directions. The bridge is excited with four different earthquake ground motions with all three components (i.e. two horizontal and a vertical) having different characteristics. It is observed that the use of semi-active PFD with LRB is quite effective in controlling the response of the curved bridge as compared with passive system. The incorporation of the smart damper requiring small amount of energy in addition with an isolation system can be used for effective control the curved bridge against the dynamic loading.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.143-146
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• 1999

A method to control the speed of DC motor with one-chip microprocessor PIC using PWM is discussed in this paper. This thesis deals with the DC motor speed control for electric bicycles which may be used as an alternative means of transformation in the future. We tried to design a stable system for controlling the speed of DC motor and materialized an electric bicycle loading this system. Now we are on the way to find out the problems this system has and work out the solutions.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.8B
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• pp.752-759
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• 2002

The capacity of the cell varies with the load of the home and neighboring cells. But most call admission control (CAC) algorithms do not consider the cell loading. In this paper a dynamic call admission control is proposed in a WCDMA system with traffic asymmetry. The proposed algorithm changes the CAC thresholds of new call and handoff call based on channel condition. The blocking and dropping probabilities can be controlled by adjusting these thresholds. The proposed algorithm guarantees the Qos of call class and priority between new call and handoff call. In addition, it can minimize the grade of service (GOS) value with the system throughput maintained.