• Journal of the Semiconductor & Display Technology
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• v.11 no.2
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• pp.33-38
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• 2012

The wafer positioning robot in the semiconductor industry is required to operate at high speed for the improvement of productivity. The residual vibration caused by the high speed of the wafer positioning robot, however, makes the life of the robot shorter and the cycle time longer. In this study, the input shaping and the path of the system are designed for the reduction of the residual vibration and the improvement of the cycle time. The followings are the process for the reduction and the improvement; 1) System modeling of the wafer positioning robot, 2) Verification of dynamic characteristics of the wafer positioning robot, 3) Input shaping plan using impulse response reiteration, 4) Simulation test using SIMULINK program, 5) Analysis of result.

• Journal of Oral Medicine and Pain
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• v.23 no.3
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• pp.277-280
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• 1998

The treatment of anterior disc displacement without reduction patients needs speicific treatment methods different from other Craniomandibular Disorders. Those are manual manipulation, anterior repositioning splint; ARS and step-back. It is well known that the use of Anterior Repositioning Splint is effective on relief of TMJ symptom. But the side effect of long- term ARS wearing, which is irreversible posterior open bite induction, has made many clinicians avoid ARS treatment. This report introduces a clinical case recently proven part- time wearing ARS method for treatment of Disc Displacement without reduction patient' that can reduce side effects with good efficacy. But now clinical statistical studies and basical histophysiological studies are more needed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.1
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• pp.24-31
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• 2012

This study is designed to predict the overall electric power load, to apply the method of time sharing and to reduce simultaneous load factor of electric power when authorized by user entering demand plans and using schedules into the user's interface for a certain period of time. This is about smart grid, which reduces electric power load through simultaneous load factor of electric power reduction system supervision agent. Also, this study has the following characteristics. First, it is the user interface which enables authorized users to enter and send/receive such data as demand plan and using schedule for a certain period of time. Second, it is the database server, which collects, classifies, analyzes, saves and manages demand forecast data for a certain period of time. Third, is the simultaneous load factor of electric power control agent, which controls usage of electric power by getting control signal, which is intended to reduce the simultaneous load factor of electric power by the use of the time sharing control system, form the user interface, which also integrate and compare the data which were gained from the interface and the demand forecast data of the certain period of time.

• Journal of the Korea Institute of Building Construction
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• v.10 no.5
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• pp.87-94
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• 2010

Construction projects are based on the actual field, so if the construction schedule that is established in the construction plan is delayed or extended for various reasons, construction companies are vulnerable to claims, and thus strive to complete a building within the planned timeline by shortening the construction time. Therefore, this study surveyed technicians in apartment construction in Gwangju, and studied their perceptions of the actual conditions of process control, construction time needs, goals, and methods. The results showed that the organization of the process control department and professional employees was lacking compared to other regions. The need for construction time was perceived as high, while the reduction of the construction cost was perceived as low. Regarding the reduction goal, they perceived highly the preparation for the delay of construction time and various claims, and for the reduction method, they mentioned the extension of working hours and the increase in employees. Based on the results of this study, technicians should consider that a reduction of construction time not only can make up for a delay in construction, but is also closely related to improvements in production through reduction of cost, and increased international competitiveness.

• Journal of the Korea Society for Simulation
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• v.8 no.1
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• pp.77-88
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• 1999

There are two approaches to handle the Causality Error in parallel and distributed simulation. One approach is based on the conservative time synchronization and the other is the optimistic time synchronization. In this paper an efficient null message reduction method for the conservative time synchronization approach is suggested with the experimental results, which could improve performance of simulation and avoid deadlock situations.

• Transactions on Electrical and Electronic Materials
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• v.14 no.5
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• pp.268-272
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• 2013

The aim of this study was to develop an ultrasonic tooth-whitening apparatus using piezoelectric transducers, which enhance bleaching efficiency by applying ultrasound, while performing a teeth whitening procedure. For this purpose, an ultrasonic transducer was designed and manufactured, and the effects of reduction in the whitening material's concentration and in the whitening treatment time through using the ultrasound cavitation phenomenon were confirmed. Also, the validity of this study was investigated by comparing the whitening performance with a commercialized optical whitener, through color comparison. The results revealed that the ultrasound whitener produced color values that were enhanced by as much as double that of the conventional LED light whitening method. Even when the operational time was reduced by half, the ultrasound method showed superior performance by over 54% compared to the conventional light whitener, revealing that the ultrasound method showed a remarkable treatment reduction effect.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.342-344
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• 2006

This paper present a method of current control for torque ripple reduction in brushless dc motor which have a trapezoid back EMF. In such drives the current ripples are generated by motor inductance in stator windings and the back EMF. The ripples suppression techniques that are practically effective in high speed as well as in low speed regions are rarely found. The proposed method here is based on a strategy that the commutation intervals of the incoming ang the outgoing phases can be equalized by a proper PWM control.

• Journal of Industrial Technology
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• v.24 no.A
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• pp.185-194
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• 2004

To evaluate seismic performance of reinforced concrete piers two procedures for capacity spectrum method are presented. The capacity spectrum procedures include the reduction factor-ductility-period($R_{\mu}-{\mu}-T$)relationship in order to construct the inelastic demand spectra from the elastic demand spectra. Application of the procedures are illustrated by example analysis. Maximum displacements estimated by the procedures are compared to those by inelastic time history analysis for several artificial earthquakes. The results show that the maximum displacements estimated by the procedures are, on overall, smaller than those by the inelastic time history analysis.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.8
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• pp.363-368
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• 2006

This paper presents a new method on reducing commutation torque ripples generated in brushless dc motor drives. In such drives the current ripples are generated by motor inductance in stator windings and the back EMF. The ripples suppression techniques that are practically effective in high speed as well as in low speed regions are rarely found. The proposed method here is based on a strategy that the commutation intervals of the incoming ang the outgoing phases can be equalized by a proper PWM control. The controller is implemented by a 16-bit microprocessor and effectiveness of the proposed control method is verified through experiments.

• Bulletin of the Korean Chemical Society
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• v.31 no.7
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• pp.1907-1914
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• 2010

A novel catalytic kinetic method is proposed for the determination of Se(IV), Se(VI) and total inorganic selenium in water based on the catalytic effect of Se(IV) on the reduction of bromate by p-nitrophenylhydrazine at pH 3.0. The generated bromine, $Br_2$ or $Cl_2$ plus $Br_2$ in 0.1 M NaCl (or NaBr) environment efficiently decolorized Calmagite and the reaction was monitored spectrophotometrically at 523 nm as a function of time. In this indicator reaction, bromide acted as an activator for the catalysis of selenium (IV) and a reducing agent for selenium (VI) at pH 3.0, which allowed the determination of total selenium. The fixed time method was adopted for the determination and speciation of inorganic selenium. Under the optimum conditions, the calibration graph are linear in the range 1 - 35 ${\mu}gL^{-1}$ of Se(IV) for the fixed time method at $25^{\circ}C$. The detection limit based on statistical $3S_{blank}$/m-criterion was 0.215 ${\mu}gL^{-1}$ for the fixed time method (7 min). All of the variables that affect the sensitivity at 523 nm were investigated, and the optimum conditions were established. The interference effect of various cations and anions on the Se (IV) determination was also studied. The selectivity of the selenium determination was greatly improved with the use of the strongly cation exchange resin such as Amberlite IR120 plus. The proposed kinetic method was validated statistically and through recovery studies in natural water samples. The RSDs for ten replicate measurements of 5, 15 and 25 ${\mu}gL^{-1}$ of Se(IV) and Se(VI) was changed between 2.1 - 4.85%. Analyses of a certified standard reference material (NIST SRM 1643e) for selenium using the fixed-time method showed that the proposed kinetic method has good accuracy. Se(IV), Se(VI) and total inorganic selenium in environmental water samples have been successfully determined by this method after selective reduction of Se(VI) to Se(IV).