• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.127.5-127
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• 2001

The 3-dimensional measuring machine by using an ultrasonic sensor is used one of the NDE (Nondestructive Evaluation). It is applied to the inspection of pipelines, boreholes, pressure vessel and tank, and so on. On particular when a harsh environment prohibits the use of moving mechanical parts. The 3-dimensional measuring machine by using an ultrasonic sensor, which measure 1-dimensional information and 2-dimensional information simultaneously from a target of inspection, and then re construct 3-dimensional information. So we can find the situation in progress and predict remaining life and corrosion without destructive examination. It´s a point of excellence that the 3-dimensional measuring machine is portable.

• Computers and Concrete
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• 제12권4호
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• pp.431-442
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• 2013

This study attempted to find a proper method applicable to simulating practical equifield lines of two-dimensional Accelerate Lithium Migration Technique (ALMT), and evaluate the feasibility of using the theoretical ion migration model of one-dimensional ALMT to predict the ion migration behavior of two-dimensional ALMT. The result showed that the electrolyte or carbon plate can be used as matrix to draw equifield line graph similar to that by using mortar as matrix. Using electrolyte electrode module for simulation has advantages of simple production, easy measurement, rapidness, and economy. The electrolyte module can be used to simulate the equifield line distribution diagram in practical two-dimensional electrode configuration firstly. Then, several equifield line zones were marked, and several subzones under one-dimensional ALMT were separated from various equifield line zones. The theoretical free content distribution of alkali in concrete under two-dimensional electric field effect could be obtained from duration analysis.

• Bulletin of the Korean Chemical Society
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• 제33권10호
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• pp.3391-3396
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• 2012

Two-dimensional infrared (2D-IR) spectroscopy can probe the fast structural evolution of molecules under thermal equilibrium. Vibrational frequency fluctuation caused by structural evolution produced the time-dependent line shape change in 2D-IR spectrum. A variety of methods has been used to connect the evolution of 2D-IR spectrum with Frequency-Frequency Correlation Function (FFCF), which connects the experimental observables to a molecular level description. Here, a new method to extract FFCF from 2D-IR spectra is described. The experimental observable is the time-dependent frequency shift of maximum peak position in the slice spectrum of 2D-IR, which is taken along the excitation frequency axis. The direct relation between the 2D-IR peak shift and FFCF is proved analytically. Observing the 2D-IR peak shift does not need the full 2D-IR spectrum which covers 0-1 and 1-2 bands. Thus data collection time to determine FFCF can be reduced significantly, which helps the detection of transient species.

• 한국공작기계학회논문집
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• 제11권2호
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• pp.24-29
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• 2002

A study for the circularity of machine tool is classified into two ways. One is to measure the circularity of machine tool by a existing measuring device. The other is to measure the circularity by remodeling the existing measuring device. We will improve on measurement of circularity using circular test method by a two-dimensional probe and a master ring for machining tools and investigate influence of trigger method, acceleration data sampling.

• 한국정밀공학회지
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• 제24권9호
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• pp.68-75
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• 2007

The pitch and orthogonality of two-dimensional (2D) gratings have been measured by using a metrological atomic force microscope (MAFM) and measurement uncertainty has been analyzed. Gratings are typical standard artifacts for the calibration of precision microscopes. Since the magnification and orthogonality in two perpendicular axes of microscopes can be calibrated simultaneously using 2D gratings, it is important to certify the pitch and orthogonality of 2D gratings accurately for nano-metrology using precision microscopes. In the measurement of 2D gratings, the MAFM can be used effectively for its nanometric resolution and uncertainty, but a new measurement scheme was required to overcome some limitations of current MAFM such as nonnegligible thermal drift and slow scan speed. Two kinds of 2D gratings, each with the nominal pitch of 300 nm and 1000 nm, were measured using line scans for the pitch measurement of each direction. The expanded uncertainties (k = 2) of measured pitch values were less than 0.2 nm and 0.4 nm for each specimen, and those of measured orthogonality were less than 0.09 degree and 0.05 degree respectively. The experimental results measured using the MAFM and optical diffractometer were coincident with each other within the expanded uncertainty of the MAFM. As a future work, we also proposed another scheme for the measurements of 2D gratings to increase the accuracy of calculated peak positions.

• 한국음향학회지
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• 제20권5호
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• pp.76-82
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• 2001

음향특성이 균일하지 않는 생체조직은 특정의 형태 유지가 어렵기 때문에 종래의 극소형 수중청음기의 스캐닝 방법에 의한 초음파 음장 전파특성 측정이 곤란하다. 본 연구에서는 PVDF (Polyvinylidene fluoride) 압전막을 사용하여 2차원 배열 수중청음기를 제작하고, 그것에 의한 음장 측정 시스템을 구축한 후, 생체조직에 적용하였다. 중심주파수 2.25 ㎒이고 직경이 13㎜인 원형평면 트랜스듀서에 의한 실험 결과, 구축한 시스템에 의해 비교적 정밀한 음장 측정이 가능한 것을 알았으며, 그 주파수에 대해 소와 돼지의 간에서는 각각 0.7∼l.3dB/cm (평균; 1.0 dB/cm), 1.0∼l.8 dB/cm (평균; 1.6 dB/cm), 근육에서는 각각 0.9∼2.9 dB/cm (평균; 2.1dB/cm), 1.7∼3.3 dB/cm (평균: 2.5 dB/cm)의 값을 갖는 감쇠계수의 공간적 분포를 측정할 수 있었다.

• Applied Microscopy
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• 제45권3호
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• pp.131-134
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• 2015

Here we show how by processing energy dispersive X-ray spectrometry (EDS) data obtained using highly sensitive, new generation EDS detectors in the AZtec LayerProbe software we can obtain data of sufficiently high quality to non-destructively measure the number of layers in two-dimensional (2D) $MoS_2$ and $MoS_2/WSe_2$ and thereby enable the characterization of working devices based on 2D materials. We compare the thickness measurements with EDS to results from atomic force microscopy measurements. We also show how we can use electron backscatter diffraction (EBSD) to address fabrication challenges of 2D materials. Results from EBSD analysis of individual flakes of exfoliated $MoS_2$ obtained using the Nordlys Nano detector are shown to aid a better understanding of the exfoliation process which is still widely used to produce 2D materials for research purposes.

• International Journal of Precision Engineering and Manufacturing
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• 제9권2호
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• pp.18-22
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• 2008

The pitch and orthogonality of two-dimensional (2-D) gratings were measured using a metrological atomic force microscope (MAFM), and the measurement uncertainty was analyzed. Gratings are typical standard devices for the calibration of precision microscopes, Since the magnification and orthogonality in two perpendicular axes of microscopes can be calibrated simultaneously using 2-D gratings, it is important to certify the pitch and orthogonality of such gratings accurately for nanometrology. In the measurement of 2-D gratings, the MAFM can be used effectively for its nanometric resolution and uncertainty, but a new measurement scheme is required to overcome limitations such as thermal drift and slow scan speed. Two types of 2-D gratings with nominal pitches of 300 and 1000 nm were measured using line scans to determine the pitch measurement in each direction. The expanded uncertainties (k = 2) of the measured pitch values were less than 0.2 and 0.4 nm for each specimen, and the measured orthogonality values were less than $0.09^{\circ}$ and $0.05^{\circ}$, respectively. The experimental results measured using the MAFM and optical diffractometer agreed closely within the expanded uncertainty of the MAFM. We also propose an additional scheme for measuring 2-D gratings to increase the accuracy of calculated peak positions, which will be the subject of future study.

• ETRI Journal
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• 제27권4호
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• pp.385-393
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• 2005

This paper presents an application of digital signal processing to data acquired by the radio imaging method (RIM) that was adopted to measure moisture distribution inside the human body. RIM was originally developed for the mining industry; we are applying the method to a biomedical measurement because of its simplicity, economy, and safety. When a two-dimensional image was constructed from the measured data, the method provided insufficient resolution because the wavelength of the measurement medium, a weak electromagnetic wave in a VHF band, was longer than human tissues. We built and measured a phantom, a model simulating the human body, consisting of two water tanks representing large internal organs. A digital equalizer was applied to the measured values as a weight function, and images were reconstructed that corresponded to the original shape of the two water tanks. As a result, a two-dimensional image containing two individual peaks corresponding to the original two small water tanks was constructed. The result suggests the method was applicable to biomedical measurement by the assistance of digital signal processing. This technique may be applicable to home-based medical care and other situations in which safety, simplicity, and economy are important.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.272-275
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• 2003

Theodolite measurement system is non-contacted 3-dimensional measurement system. The system accuracy is 0.5 mm or better for distance 0 ~ 100 m. And the system is used for the measurement of a product for middle and large scale. This study was performed for finding the measurement error factors of the system. We could know that the main error factors are temperature, illumination and expertness. And we could find the measurement errors are $\pm$ 0.045 mm at temperature conditions is 2$0^{\circ}C$ and $\pm$ 0.012 mm at illumination condition is 300 lux. Also the results had significant differences by combinations of operator's expertness.