• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.121-121
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• 2000

This paper presents a design of macro-micro system for high-speed mounting of micro-chips. A macro motion device is driven by DC servomotor and ball screw mechanism. To obtain fast response, a micro motion device utilizes a precision elector magnetic actuator In order to reduce peak impact force, We evaluate the design parameters that have an effect on it. And a characteristic of response is simulated using PID controller in velocity and force control.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.19 no.3
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• pp.305-325
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• 2015

In this paper, missile homing guidance laws to control the impact angle and time are proposed based on the polynomial function. To derive the guidance commands, we first assume that the acceleration command profile can be represented as a polynomial function with unknown coefficients. After that, the unknown coefficients are determined to achieve the given terminal constrains. Using the determined coefficients, we can finally obtain the state feedback guidance command. The suggested approach to design the guidance laws is simple and provides the more generalized optimal solutions of the impact angle and time control guidance.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.6
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• pp.28-34
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• 2004

The old technique of sandblasting which has been used for decoration of glass surface has recently been developed into a powder blasting technique for brittle materials such as glass, silicon and ceramics, capable of producing micro structures larger than 100${\mu}{\textrm}{m}$. In this study, we introduced oblique powder blasting, and investigated the effect of the impacting angle of particles, the scanning times and the stand-off distance on the surface roughness and the weight-loss rate of samples with no mask, and the wall profile and overetching of samples with different mask pattern in powder blasting of soda-lime glass. The varying parameters were the different impact angles between 50$^{\circ}$ and 90$^{\circ}$, scanning times of nozzle up to 40 and the stand-off distances 70mm and 100mm. The widths of mask pattern were 0.2mm, 0.5mm and 1mm. The powder was alumina sharp particles, WA #600. The mass flow rate of powder during the erosion test was fixed constant at 175g/min and the blasting pressure of powder at 0.2Mpa.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.46.5-46
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• 2002

As device dimension shrinks down to sub 100nm, it is increasingly important to monitor plasma states. Plasma etching is a key means to fine patterning of thin films. Many parameters are involved in etching and each parameter has different impact on process performances, including etch rate and profile. The uniformity of etch responses should be maintained high to improve device yield and throughput. The uniformity can be measured on any etch response. The most difficulty arises when attempting to characterize etched profile. Conventionally, the profile has been estimated by measuring the slope or angle of etched pattern. One critical drawback in this measurement is that this is unable to cap...

• Geomechanics and Engineering
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• v.16 no.6
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• pp.569-575
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• 2018

The stability of shallow cavities with an arbitrary profile is a difficult issue in geotechnical engineering. This paper investigates this problem on the basis of the upper bound theorem of limit analysis and the Hoek-Brown failure criterion. The influence of pore pressure is taken into consideration by regarding it as an external force acting on rock skeleton. An objective function is constructed by equating the internal energy dissipation to the external force work. Then the Lagrange variation approach is used to solve this function. The validity of the proposed method is demonstrated by comparing the analytical solutions with the published research. The relations between shallow and deep cavity are revealed as well. The detaching curve of cavity roof with elliptical profile is obtained. In order to facilitate the application of engineering practice, the numerical results are tabulated, which play an important role in tunnel design and stability analysis of roof. The influential factors on potential collapse are taken into consideration. From the results, the impact of various factors on the extent of detaching is seen intuitively.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.247-248
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• 2023

The unit curtain wall is an exterior finish currently used on the exterior walls of high-rise buildings. Although the structural impact is not significant due to the non-strength wall, in the case of the unit curtain wall to which the factory manufacturing method is applied, deformation of the profile may occur according to its own weight. Therefore, in this study, stability is evaluated through design standard calculation applied when finishing the outer wall according to the design shape of the unit curtain wall profile.

• Proceedings of the KAIS Fall Conference
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• 2010.11b
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• pp.893-896
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• 2010

본 연구는 환자가 느끼는 자신의 주관적 구강보건영향지수(OHIP-14; Oral Health Impact Profile-14)가 구강보건이 삶의 질(QOL; Quality of Life)에 어떤 영향을 미치는지 알아보고 구강질환 예방과 구강보건 향상을 위한 프로그램을 개발하는데 필요한 기초 자료를 제공하여 지역사회주민의 건강과 삶의 질을 증진하고자 한다. 주관적 구강건강상태에 따른 OHIP를 분석한 결과 자가 인식 구강건강상태는 전 영역에서 유의한 차이가 있었고, 총 점수가 건강한 편이 4.33으로 유의하게 높았다. 주관적 구강건강상태에 따른 QOL을 분석한 결과 자가 인식 구강건강상태에서는 사회적 영역을 제외한 전 영역에서 유의한 차이가 있었으며, 총 점수는 건강한 편이 3.39로 가장 높았다.

• The Journal of Internal Korean Medicine
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• v.34 no.4
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• pp.456-465
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• 2013

Objectives : A case of cervical dystonia improved after Korean medical treatments by using measurements of Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS), and Cervical Dystonia Impact Profile (CDIP-58) to evaluate the changes of symptoms. Methods : Korean medical treatments for relieving symptoms of cervical dystonia including acupuncture, herb medication, cupping therapy, and physical therapy were performed. To evaluate the effect of the treatments, TWSTRS and CDIP-58 were used. Results : TWSTRS decreased from 55 to 24.5 and CDIP-58 also decreased from 79.3 to 36.2. Conclusions : This report suggests that Korean medical treatments can be effectively used for patients with cervical dystonia. Further clinical studies are needed to verify the findings.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.2
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• pp.109-117
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• 2014

This paper reports a method to modify the gear tooth profile of a wind turbine gearbox to reduce the noise caused by the impact of the gear teeth. The major causes of tooth impact are the elastic deformation of the gear teeth, shafts, and case of the gearbox under loading, and the fabrication tolerances in gear manufacturing. In this study, the tooth profile was modified considering the elastic deformation of the gear tooth and the tooth lead modification to compensate for tooth interference in the lead direction as a result of shaft deformations. The method was applied to the gearbox of a 2.5MW wind turbine, and the transmission error was characterized before and after modifying the gear teeth. For the modified gear teeth, the transmission error (67.6%) was lower by 17.8%. Additionally, the gear contact stress was reduced by 6.3%, to 22.3%.

• International Journal of Automotive Technology
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• v.8 no.2
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• pp.225-232
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• 2007

A tooth profile modification for loaded gears is used to avoid a tooth impact. Since a tooth profile error causes amplification of the cumbersome whine noise in automotive gear transmissions, an optimal quantity of tooth profile modifications must be obtained for good performance in the vibration sense. In this paper, a tooth profile modification curve considering profile manufacturing errors and elastic deformation of the gear tooth is formulated; in addition, transmission errors of the gear system with modified teeth are verified. The equivalent excitation due to transmission errors is formulated. For experimental evaluation of the transmission error, the transmission error for a simple gear system was measured by two rotational laser vibrometers. Finally, we perform a comparative analysis between the calculated and measured responses to the excitations due to the transmission error to verify the practicability of the application to automotive transmissions.