• Journal of Ocean Engineering and Technology
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• v.12 no.2 s.28
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• pp.121-129
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• 1998

A quantitative non-contact multi-point measurement system is proposed to the measurement of three-dimensional movement of floating vessels by using digital image processing. The instantaneous three-dimensional movement of a floating structure which is floating in a small water tank is measured by this system and its three-dimensional movement is reconstructed by the measurement results. The validity of this system is verified by position identification for spatially distributed known positional values of basic landmarks set for the camera calibration. It is expected that this system is applicable to the non-contact measurement for an unsteady physical phenomenon especially for the measurement of three-dimensional movement of floating vessels in the laboratory model test.

• Journal of Electrochemical Science and Technology
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• v.11 no.2
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• pp.180-186
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• 2020

In this work, a metal-ligand solution (Cu-EDTA) was prepared based on the molecular precursor method and the solution was spin-coated onto 3D printed flexible photosensitive resin sheets. After being processed by microwave, a laser with a wavelength of 355 nm was utilized to scan the spin-coated sheets and then the sheets were immersed in an electroless copper plating solution to deposit copper wires. With the help of microwave processing, the adhesion between copper wires and substrate was improved which should result from the increase of roughness, decrease of contact angle and the consistent orientation of coated film according to the results of 3D profilometer and SEM. XPS results showed that copper seeds formed after laser scanning. Using the 3D printed flexible sheets as cathode and galvanized iron as anode, electrochemical machining was conducted.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.292-295
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• 2003

Moire topography method is a well-known non-contacting 3-D measurement method. the automatic 3-D measurement by moire topography has been required since the method was frequently applied to the engineering and medical fields. 3-D measurement using digital projection moire topography is very attractive because of its high measuring speed and high sensitivity. In this study, digital two-wavelength phase shilling moire is applied to the entertainment fields. recently. as promoting the growth of the VR-Game, display devices which attract public attention such as HMD or Projector are being appeared in order to deliver effectively the absorption sense. this study realized the Auto-calibrating system for arbitrary display surface using digital moire method which satisfied the shape measurement of display surface and the request of FOV(Field of View) output. also when large screen wasn't prepared, this auto-calibrating system was applied to enjoy games or movies at home with a projector and walls

• Journal of Computing Science and Engineering
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• v.11 no.3
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• pp.79-91
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• 2017

In this paper, the abdominal-deformation measurement scheme is conducted on a shape-flexible mannequin using the DIC technique in a stereo-vision system. Firstly, during the integer-pixel displacement search, a novel fractal dimension based on an adaptive-ellipse subset area is developed to track an integer pixel between the reference and deformed images. Secondly, at the subpixel registration, a new mutual-learning adaptive particle swarm optimization (MLADPSO) algorithm is employed to locate the subpixel precisely. Dynamic adjustments of the particle flight velocities that are according to the deformation extent of each interest point are utilized for enhancing the accuracy of the subpixel registration. A test is performed on the abdominal-deformation measurement of the shape-flexible mannequin. The experiment results indicate that under the guarantee of its measurement accuracy without the cause of any loss, the time-consumption of the proposed scheme is significantly more efficient than that of the conventional method, particularly in the case of a large number of interest points.

• Journal of the Korea Society of Computer and Information
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• v.24 no.12
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• pp.191-199
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• 2019

In this paper, we propose to develop a diagnosis tool for measuring digital competence for university student. To this end, 223 students participated for the survey research. Based on the survey by 6 domain and 40 questions, 6 factors and 18 questions for digital competence measurement were drawn throughout the factors analysis. The results of the confirmatory factor analysis showed the fact that 6 factors and 18 questions that satisfied the model-fit indexes statistically were finally confirmed. And the developed tool demonstrated good results in reliability and validity verification, which were suitable for measuring digital competence for university students. The developed measurement tool of digital competence for university students consisted of 6 sub-components such digital device operation, communication and collaboration, information searching, processing, and management, problem solving and learning, security, digital ethics. The digital competence measuring tool developed in this study is expected to be used to identify the current level of competences for university student, and to enhance their own digital competences through educational supports.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.371-372
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• 2006

In this paper, we propose a method that measures quality of digital correlator. Quality of digital correlator in field of image composition of radio astronomy have as important position for acquisition of radio wave image with high precision. Digital correlator should have wide bandwidth and high precision to study on deep space. Digital correlator, therefore, should be designed to have high speed processing and high precision. But, real time measurement of quality of digital correlator using acquisition data is difficult to compare accuracy of result because digital correlator should process a large quantity of data with high speed. Measurement method of quality, also, has intricate implementation of experiment equipment. this paper present methods that compose experiment equipment without external installation easily and verify quality of digital correlator perfectly.

• Tunnel and Underground Space
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• v.20 no.6
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• pp.421-433
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• 2010

The digital images to be used for digital vision measurement like digital face mapping and photogrammetric monitoring in construction could be influenced by various conditions such as a kind of light, the intensity of radiation, camera set-up and so on. Because it is very difficult to assess the rock mass from the digital images acquired under different circumstances, some tests and analysis are carried out to modify the images to be suitable and consistent for the digital image optimization. As a result, the recommended conditions for the acquisition of optimized digital images are suggested.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.7
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• pp.625-634
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• 2016

A full digital receiving active phased array antenna generates final receiving beams by digital beam forming of received digital signals in element-level that makes difficult to use typical near-field measurement method. Thus in this paper, a modified near-field measurement method which is suitable for full digital receiving active phased array antenna is proposed. Also the measured results of receiving beam pattern and G/T using developed L-band full digital receiving active phased array antenna are shown for the verification of proposed method.

• Journal of the Korean Institute of Navigation
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• v.24 no.5
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• pp.443-450
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• 2000

Before some experiments were carried out with analog bandpass filter which used for filtering the noise included in sound source signal. And this filter was constituted by condenser, register and operational amplifier. Hut these elements made the phase characteristics to differentiate in each sensing channel and cause a little of measurement error. We made new measurement system that was substituted digital filter for the analog filter in order to develop the optimal system which could find the time delay between each sensors with high accuracy. This paper describes the new system's constitution and the function of each parts. Specially three digital filters were designed and applied to the digital signal processing Part. And a series of experiments were carried out with the source＇s distance 9.53meters and the random bearing interval within the limits of $0^{\circ}$ ~ $180^{\circ}$. As a result, we have recognized that the accuracy of measurements were differentiated by the methods what kind of digital filter were adopted. And we have confirmed the facts that IIR LPF was suitable for sound source's bearing measurement and FIR LPF reduced the range measurement error.

• Journal of Korean Library and Information Science Society
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• v.41 no.1
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• pp.121-147
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• 2010

The purpose of this study is to develop and prove service quality measurement model and indicators which are able to measure objectively service quality of digital libraries in Korea. Literature review and Delphi survey are used to investigate service quality dimensions. User perceived service quality performance was measured to validate DL-SQI model with three digital libraries. Finally DL-SQI(Digital Library-Service Quality Index) model was developed which is composed of four primary dimensions. The survey results reveal that reliability coefficient is 0.8 which means high reliability of survey and it suggests that DL-SQI model based on the above dimensions is proved through confirmatory factor analysis.