• Journal of the Korean Society for Precision Engineering
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• v.22 no.4
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• pp.151-158
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• 2005

An important component of a cooling tower is an axial fan, and there happens distortion in its shape which brings significant loss of efficiency. In this paper, a surface profile measuring system for large size axial fan of cooling towers is developed. A laser sensor is used as a measuring device and aluminum profiles and stepping motors are engaged into the system as frame structure and driving devices respectively. The measuring data are compared to the design data to compute the distortion of the axial fans. Two types of errors, axial and twist errors, are used to represent the precision of axial fan distortion. Genetic algorithm is used to solve the optimization problem during computing the precision. Results are displayed three dimensionally in a solid-modeler as well as 2-D drawings to help users find it with ease.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.10
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• pp.1730-1741
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• 1997

In this paper, we developed a surface profile measuring system and a profile measuring software for EGL conductor roll. For the profilemeter, we designed a linear guided control system with Laser displacement sensors and developed a 3-dimensional software. Additionally, the AC motor and AC motor driver were used to control the precise position of linear guide system. The measuring principle of the Laser sensor is optical triangulation method. Also, two Laser sensors were used to remove the disturbance and vibration effects of the linear guide system.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.2
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• pp.86-94
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• 1993

In heavy industries forces which are exceeding the range of available force standard machines have to be measured. Force measuring system using build-up procedure can be applied to measure large forces efficiently. In this study strain gage type force sensors are designed and fabricated, and the build-up force measuring system with 4.5 MN capacity using the developed force sensors is 0.03% or less over the range of 600 kN .approx. 1.5 MN and the force measuring system is less than 0.06% or less over the range of 500 kN .approx. 4.5 MN.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.86.1-86
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• 2001

Combined with a counter, wheel or strip encoders which have equally divided markers are one of frequent measuring choices towards various applications in terms of cost, simplicity, and diversity of measurements, e.g., measuring displacement, velocity, acceleration, and so on. Often, velocity is measured by counting the series of reference clocks for a period of time which sensor-carrying device took for traveling two adjacent encoding markers. Quantizaion error of such that the disturbance caused by quantization error is under control. This paper identifies design issues, developes theory, and proposes a paradigm to design a velocity measurement system such ...

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.411-413
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• 2002

In this paper we researched about the ultrasonic cane which aids the blind to walk. We used ultrasonic in recognizing the object and implemented pulse counting method in measuring the distance. The distance measuring system consists of transmitter unit, receiver unit and micro-processor. We used broadband ultrasonic sensors in transmitter unit and receiver unit. The blind is able to recognize the distance between obstacles and himself as it used a vibration system.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1378-1383
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• 2004

Rogowski coil is a kind of sensor for high amplitude and very short period current and suitable for the measurement of PD pulse. This paper have simulated the relations between PD signals and Rogowski coil which has its own equivalent circuit and investigated signals of Rogowski coil induced by PD pulse current. and compared with the PD signal obtained from conventional PD measuring system in accordance with IEC60270.

• Journal of the Korean Geotechnical Society
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• v.23 no.4
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• pp.15-24
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• 2007

Two kinds of temperature monitoring technology have been introduced in this study, which can measure coincidently temperatures at many points along a single length of cable. One is to use a thermal sensor cable comprizing of addressable thermal sensors. The other is to use an optic fiber sensor with Distributed Temperature Sensing (DTS) system. The differences between two technologies can be summarized as follows: A thermal sensor cable has a concept of "point sensing" that can measure temperature only at a predefined position. The accuracy and resolution of temperature measurement are up to the capability of the individual thermal sensor. On the other hand, an optic fiber sensor has a concept of "distributed sensing" because temperature is measured practically at all points along the fiber optic cable by analysing the intensity of Raman back-scattering when a laser pulse travels along the fiber. Thus, the temperature resolution depends on the measuring distance, measuring time and spatial resolution. The purpose of this study is to investigate the applicability of two different temperature monitoring techniques in technical and economical sense. To this end, diverse experiments with two techniques were performed and two techniques are applied under the same condition. Considering the results, the thermal sensor cable will be well applicable to the assessment of groundwater flow, geothermal distribution and grouting efficiency within about loom distance, and the optic fiber sensor will be suitable for long distance such as pipe line inspection, tunnel fire detection and power line monitoring etc.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1395-1398
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• 1997

Flexible parts comparing with rigid parts can be deformed by contact force during assembly. for successful assembly, information about their deformation as well as possible misalignment between mating parts is essential. Howecer, because of the complex relationship between parts deformation and reaction forces, it is difficult to acquire all required information from the reaction forces alone. In this paper, we measure parts deformation and misalignments by using the visual sensing system presented for flexible parts assembly. Experimental results show that the system can be effectively used for detecting parts deformation and misalignments between mating parts.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.551-552
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• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.951-952
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• 2010