• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.8
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• pp.2555-2560
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• 1996

Inspecting the dimensional accuracy of a car-body in assembly line is a very important process to assure high productivity. Now there exist two common inspecting methods in practice. One is to measure a sampled car-body with three dimensional measuring machine, and the other is to measure car-body with three dimensional measuring machine, and the other is to measure car-body in assembly line using many sensors fixed to a large jig frame. The formal method takes too long to inspect a sampled car-body of a same sort, and cannot therefore give an useful error trend for the whole production. On the other hand, the latter lacks flexibility and is very cost-intensive. By using industrial robots and sensors, an in-line Car-Body Measuring(CBM) system which ensured high flexiblity and sufficient accuracy was developed. This CBM cell operates in real production line and measures the check points by the non-contact type using camera and laser displacement sensor(LDS). This system can handle about 15 Measuring points within a cycle time of 40 seconds. A process computer controls whole process such as data acquisition file handling and data analysis. Robot arms changes in length due to ambient temperature fluctuation affecting the measuring accuracy. To compensate this error, a robot arm calibration process was developed.

• Journal of Korea Entertainment Industry Association
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• v.13 no.6
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• pp.69-77
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• 2019

Among the many factors that threaten the improvement of public health and quality of life, the proportion of fine dust is not so small, and the kinds and causes of the dust are also diversified. However, the domestic measuring instrument is in the initial stage and the certification system is insignificant. Recognizing the threat of fine dust for a long time, the United States has established a protocol of measurement standards and measurement methods and applied the developed fine dust measuring device authentication system. Through this system, the United States is leading the world's fine dust industry, technology and market. The EPA, FRM and FEM of the fine dust-related protocol were analyzed to reduce the harmful effects of repeated fine dust every year. In addition, light scattering method and spectroscopy method which can measure in real time by measuring method were examined, and the types and characteristics of fine dust measuring instrument of international certification level were analyzed. Finally, development and service plan of the domestic fine dust measuring instrument are presented.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.2
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• pp.143-152
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• 2012

It is well-known that image matching is necessary for automatic generation of 3D data such as digital surface data from aerial images. Recently developed aerial digital cameras allow to capture multi-strip images with higher overlaps and less occluded areas than conventional analogue cameras and that much of researches on multi-image matching have been performed, particularly effective methods of measuring a similarity among multi-images using point features as well as linear features. This research aims to investigate similarity measuring methods such as SSD and SNCC incorporated into a area based multi-image matching method based on vertical line locus. In doing this, different similarity measuring entities such as grey value, grey value gradient, and average of grey value and its gradient are implemented and analyzed. Further, both dynamic and pre-fixed adaptive-window size are tested and analyzed in their behaviors in measuring similarity among multi-images. The aerial images used in the experiments were taken by a DMC aerial frame camera in three strips. The over-lap and side-lap are about 80% and 60%, respectively. In the experiment, it was found that the SNCC as similarity measuring method, the average of grey value and its gradient as similarity measuring entity, and dynamic adaptive-window size can be best fit to measuring area-based similarity in area based multi-image matching method based on vertical line locus.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.63.2-63.2
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• 2010

Solar radiation data are used in several forms and for a variety of purposes. The most detailed information we have is beam and diffuse solar radiation on a horizontal surface, by hours, which is useful in simulations of solar processes. Daily data are more often available and monthly total solar radiation on horizontal surface can be used in some process design methods. However, as performance is generally not linear with solar radiation, the use of average may lead to serious errors if non-linearities ara not taken into account. It is also possible to reduce radiation data to more manageable forms by statistical methods. The control of the quality of most measurements is relegated to the control of the measuring instruments and measuring processes themselves. An accurate measurement will usually result from the use of a high-quality instrument that has been accurately calibrated and is properly used by a qualified individual.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.631-635
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• 2006

In this study, simplified methods on measurement and evaluation of heavy-wight impact sound was proposed due to provide easy quality control method to construction engineers. The simplified methods include using of rubber impact ball instead of bang machine, reduced number of measuring and impact positions which is prescribed as over 4 points, using of hand-held sound level meter as a frequency analyser and prediction equation for $L_{i.Fmax.AW}$, single number rating, using $L_{Amax}$, and $L_{Lmax}$ at each frequency band. The results showed that a method of boundary driving and boundary measuring is the most similar to the current rating method.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.6 s.183
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• pp.57-63
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• 2006

Gravitational centers of precise spinning components must coincide with the rotational centers of those to reduce noise and vibration and to extend those lift as well. Therefore quality control should be performed in the manufacturing process, in which the unbalance moments are accurately measured. In this paper 3-point weighing method is adopted to measure the unbalance moment of small-sized precision spinning elements using electronic scales with 0.1 mg resolution. Firstly methods to eliminate the fixture error and to reduce the effects of frictional force that is known as side effect, are proposed. A measuring system is developed and various experiments are performed to verify the proposed approach. The measured and calculated values are analysed in statistical methods, and this provides the errors of the measuring system. The results show that the proposed theory and test procedures gives reliable unbalance moments and gravitational centers.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.929-934
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• 2004

As 3D scanner develops, it can be used in measurement. To accomplish complete 3D measurement, the scanner has to view different sides of the target. It can be done by moving the scanner and fix it at every measuring point. By human, it would take so much time. However, by using robot, measuring time can be reduced and the procedure can be automated. It is suitable for 6R serial manipulator to do this kind of work in which the scanner should go any position in arbitrary orientation. We did inverse kinematics analysis by analytical and graphical methods. Then, we compared two methods.

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.6
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• pp.565-573
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• 2020

Unlike fin-stabilized projectiles, there has been some difficulty measuring the attitudes of spin-stabilized projectiles during the long-range flight due to their high spin rates. In this work, solar and geomagnetic sensors were used to measure the attitude of a spin-stabilized projectile. A method to calculate the attitude of the projectile from the signals of the sensors was introduced as well as the methods to process the signals of the sensors. To validate the methods, the attitude of a projectile was calculated with the sensor signals from the actual flight data.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.407-410
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• 1995

Many researches on measurement technology has been made and developed by various methods. Considering the measurement environment with cutting fluid, coolant and the like, contact type measurement methods are mostly used. But contact measurement method has measuring force and so the sensing head becomes worn. By these reasons, we considered sensors not influenced by the former fluid and so can acquire accrate measured values using error compensation due to temperature and vibration. For this purpose, eddy current sensors and Extended kalman Filter Algorithm for processing measured data has been used. In this paper, we present new technology that can be used for measuring workpiece with previous bad environment using direct method and comparison measurement method. We used cylindrical workpieces which were produced by grinding machine for the target.

• Journal of the Korean Graphic Arts Communication Society
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• v.21 no.2
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• pp.89-100
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• 2003

We have reviewed the method for surface tension of printing inks. Most of the methods fir for the low viscosity inks and solvents for inks. However, the inks for the offset lithography and intaglio should have high viscosity and high tack. The elongation of the ink filaments has more effect on the measuring surface tension than the energy of the surface molecules. In this paper, we propose the elongation method to estimate the surface tension of high viscosity printing inks. Even though we could measure the surface tension for low viscosity inks such as gravure and screen, elongation method could more useful to estimate the surface tension of lithography and intaglio inks than any other methods.