• 한국GIS학회:학술대회논문집
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• 한국GIS학회 2008년도 공동추계학술대회
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• pp.203-204
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• 2008

EGM96 지구중력장모델을 개선시킨 EGM2008 지구중력장모델이 미국 NGA에 의해 발표됨에 따라, 본 연구에서는 EGM2008지구중력장모델을 한반도 지역을 대상으로 최대차수 360으로 해석하여 기존의 지구중력장모델인 EGM96(360차수) 및 EIGEN-GL04C(360차수)와 비교하였다. 또한 EGM2008은 기존의 구면조화분석한계인 360차수를 뛰어넘고 있으므로 격자 간격 $30'{\times}30'$ 및 $15'{\times}15'$, 그리고 $10'{\times}10'$로 각각 해석하여 지오이드고를 계산하고 정확도를 평가하였다. 정확도 평가는 우리나라의 수준점에서 GPS측량을 실시한 464점의 GPS/leveling 데이터를 활용하였다. 평가결과 EGM2008(360차수)은 $-0.100{\pm}0.183m$를 나타내 EGM96(360차수)결과인 $0.156{\pm}0.238m$에 비해 상당한 정확도의 개선을 가져왔으며, 2190차수의 고차항으로 해석한 결과 $-0.069{\pm}0.140m$ 더욱 정확한 결과를 얻을 수 있음을 확인하였다.

• 한국영어학회지:영어학
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• 제1권2호
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• pp.243-272
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• 2001

This paper focuses on the applicability of paradigm to derivational morphology and the pressure of paradigm enforced on derivational phonology and morphology. Through a close examination of well-attested data, we will demonstrate that apparent surface idiosyncrasies in phonology are the results of paradigm leveling, and that paradigmatic forces of analogy are productively operating in English word formation. On the basis of these observations, it can be argued that the notion of paradigm has at least some justification within derivational morphology as well, even if not to the same extent that it has with inflectional morphology and that the paradigm forces are independently needed in any adequate phonological and morphological theory. This can also be extended to provide evidence against the split morphology hypothesis that inflectional and derivational morphology belong to different grammatical modules.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.132.5-132
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• 2001

In teleoperation field robotic system such as hydraulically actuated robotic excavator, the maneuverability and convenience is the most important part in the operation of robotic excavator. Particularly the force information is important in dealing with digging and leveling operation in the teleoperated excavator. Excavators are also subject to a wide variation of soil-tool interaction forces. This paper presents a new force reflecting joystick in a velocity-force type bilateral teleoperation system. The master system is electrical joystick and the slave system is hydraulically actuated cylinder with linear position sensor. Particularly Pneumatic motor is used newly in the master joystick for force reflection and the information of the pressure of salve cylinder is measured and utilized as the force feedback signal. Also force-reflection gain greatly affects the ...

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.65.6-65
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• 2002

In teleoperation robotic system such as hydraulically actuated robotic excavator for dangerous area, the maneuverability and convenience is the most important part. Particularly the force information is important in dealing with digging and leveling operation in the tole-operated excavator. Excavators are also subject to a wide variation of soil-tool interaction forces. This paper proposes a new force reflecting joystick using pneumatic motor and a new algorithm for selecting force-reflecting gain in a velocity-force type bi lateral teleoperation system. The master system is electrical joystick with the same structure of that of real excavator. Particularly Pneumatic motor is used newly in...

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2003년도 추계학술대회
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• pp.71-76
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• 2003

This paper describes the characteristic of a large-diameter pipe to obtain smooth surface using Electropolishing after grinding using a non-woven fabric. Grinding using a non-woven fabric is possible under lower load and fine effect comparing with Wheel grinding. Also, the ion from the surface of the metal is eliminated by means of an electrical potential and current in Electropolishing. Electropolishing is used for leveling the surface, improving the physical appearance of the part, promoting corrosion properties and reducing contamination and adhesion of the surface. Therefore, the aim of the present study is to investigate the internal machining of a large-diameter pipe for semiconductor using experimental design method.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.756-760
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• 1997

In this research, the automatic level measurement system used in land leveling was developed. By using a laser transmitter and a receiver as measuring equipments, level was measured automatically. The driving part of this system was composed of stepping motor, timing belt and pulley. It drived the laser receiver to track laser beam generated form the laser transmitter. The level measuring experiments were performed about three level change shapes (step, random, sine). This system could measure step level change of which amplitude was 40mm in 0.5s, random level change within .+-. mm, maximum measurement error. In case of sine level change, experiment was executed with varying the spatial frequency of level change. As a result, this system was able to measure sine level change of which spatial frequency was 0.5m $^{-1}$ accurately.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 추계학술대회 논문집
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• pp.227-228
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• 2006

• 한국정밀공학회지
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• 제30권2호
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• pp.148-153
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• 2013

This study demonstrates a novel hybrid surface polishing process combining non-traditional electrochemical polishing(ECP) with external artificial ultrasonic vibration. ECP, typical noncontact surface polishing process, has been used to improve surface quality without leaving any mechanical scratch marks formed by previous mechanical processes, which can polish work material by electrochemical dissolution between two electrodes surfaces. This research suggests vibration electrochemical polishing(VECP) assisted by ultrasonic vibration for enhancing electrochemical reaction and surface quality compared to the conventional ECP. The localized roughness of work material is measured by atomic force microscopy(AFM) for detailed information on surface. Besides roughness, overall surface quality, material removal rate(MRR), and productivity etc. are compared with conventional ECP.

• 한국산업정보학회:학술대회논문집
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• 한국산업정보학회 1999년도 춘계학술대회 발표논문집
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• pp.135-144
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• 1999

A major concern in Concurrent Engineering is the control and management of workload in a period of process. As a general rule, leveling the peak of workload in a certain period is difficult because concurrent processing is comprised of various processes, including overlapping, paralleling and looping. Therefore, workload management with resource constraints is so beneficial that effective methods to analyze design process This study presents a procedure to transform the IDEF3 process model into the precedence logic network model for more useful assessment of the process. This approach is expected to facilitate resolving resource constrained scheduling problems more systematically in Concurrent Engineering environment.

• 설비공학논문집
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• 제16권1호
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• pp.34-41
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• 2004

The chemical heat pump based on the Dehydration/Hydration process with a MgO/$H_2O$ system has been researched. The reactor bed could be expected to store the heat around 200∼37$0^{\circ}C$ by the dehydration reaction and to release the heat around 100∼16$0^{\circ}C$ by the hydration reaction under the heat amplification mode operation. The heat output rate of the heat pump system was evaluated using the experimentally determined parameters. The results show that 6∼50 W/kg of heat output and 0.5∼0.8 of heat recovery ratio are attainable. The heat pump will be applicable for a load leveling in a co-generation system by chemical storage of surplus heat at low heat demand and by supplying heat in the peak load period.