• Journal of Biomedical Engineering Research
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• v.6 no.2
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• pp.53-62
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• 1985

The position and time interval of wave components of the electrocardiogram are used as important data for physician's diagnosis. In case of using the existing definition of the onset of the wave component of the electrocardiogram, they have some problems of defining the precise position of the isoelectric line, of defining the limit of the gradient accepted as the onset, and of the gradient being changed by noise. Therefore, in this paper all time intervals and positions of wave components needed for data of diagnosis were obtained correctly by turning point data reduction algorithm and linear regression intersection algorithm, and the viability of the method of intersecting lines was established in comparison to the four methods of calculating the PR interval.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.93-96
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• 2022

DTW can eliminate gaps between sequences of different lengths and find out the similarity of patterns, but due to the time and space complexity, it requires a high computational cost on large datasets. In this paper, we propose a DDTW algorithm that not only reduces computational costs but also has no error in the results. In addition, the algorithm complexity of DTW and DDTW is compared by measuring the computational time according to the length of the sequence. Simulation results show a noticeable reduction in computational time in DDTW compared to DTW.

• Journal of the Semiconductor & Display Technology
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• v.18 no.1
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• pp.15-20
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• 2019

Inspection and measurement of surface quality is one of the most critical processes for manufacturing products such as semiconductor wafers, sapphire substrates, and display panels. The vibrations of the inspection and measurement devices are supposed to be the most dominant factors for severe measurement errors and longer measuring time. In this study, dynamic characteristics of an inspection and measurement device are analyzed through frequency response experiment and computer simulation to obtain parameters such as frequencies, magnitudes, mode shapes, and periods of vibrations. And then an active damper which consists of sensor, interface board, and actuator is designed based on the parameters to formulate the most effective reaction signal to suppress the vibrations which is generated by an interface board, and provided by an actuator. If the vibrations are measured by the sensor, the active damper immediately generates and provides the corresponding reaction signal to inspection and measurement device. The result shows that the active damper can suppress structural vibrations effectively and reduce measuring time of the device and enhance the productivity.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.4
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• pp.295-301
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• 2016

The out-of-squareness is one of the error sources that affect the positioning accuracy of machine tools and coordinate measuring machines. Laser interferometer is widely used to measure the position and angular errors, and can measure the squareness using an optical square. However, the squareness measurement using the laser interferometer is difficult, as compared to other errors due to complicated optics setup and Abbe's error occurrence. The effect of out-of-squareness mainly appears at the face-diagonal of the movable plane. The diagonal displacements are also affected by the position dependent geometric errors. In this study, the squareness estimation techniques via diagonal displacement measurement using the laser interferometer without an optical square were proposed. For accurate estimation and measurement time reduction, the errors selected from proposed discriminant were measured. Discrepancy between the proposed technique with the laser interferometer (with an optical square) result was $0.6{\mu}rad$.

• Journal of Korea Society of Digital Industry and Information Management
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• v.12 no.4
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• pp.25-31
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• 2016

In this research, to analyze the concentration of heavy metal ions in water, we tried to find the measuring time at which the faradaic electric currents flowing by the pure oxidation-reduction reaction from the pushing up mercury electrode of the stripping scan square wave voltammetry(SV+SWV) methods system becomes larger than the capacitance electric current. In order to do this, a method for analyzing signals using FPGA has been designed and we conducted 120 experiments using it. As a result, when the frequency of the square wave is 40Hz, The valid potential-current signal was measured from 96.6667% to 96.7155% of the end of the pulse of the forward and reverse, and the optimal signal was measured at 96.6667%. In addition, the experiment was carried out 40 times by changing the pulse height of the square wave from 10Mv to 40Mv. As a result, at a size smaller than 40Mv, there is little change in the magnitude of the potential-current, and an invalid signal was generated when it is out of this size.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.8
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• pp.1246-1252
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• 2001

Reverse engineering has been widely used for the shape reconstruction of an object without CAD data and the measurement of clay or wood models for the development of new products. To generate a surface from measured points by a laser scanner, typical steps include the scanning of a clay or wood model and the generation of manufacturing data like STL file. A laser scanner has a great potential to get geometrical data of a model for its fast measuring speed and higher precision. The data from a laser scanner are composed of many line stripes of points. A new approach to remove point data with Delaunay triangulation is introduced to deal with problems during reverse engineering process. This approach can be used to reduce a number of measuring data from laser scanner within tolerance, thus it can avoid the time for handling point data during modelling process and the time for verifying and slicing STL model during RP process.

• Journal of Korea Society of Digital Industry and Information Management
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• v.14 no.4
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• pp.101-107
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• 2018

In the stripping scan square wave voltammetry (SV+SWV) polarography that is often used to analyze the concentration of heavy metals in water, we must measure the point where the faradic current that flows by the pure oxidation-reduction reaction at the electrode is greater than the capacitive current, the frequency cannot be too high. Therefore we wanted to find the frequency range that can be measured. In order to do this, we came up with a method to analyze the signal using FPGA Soc. With this method, the frequency of the square wave was increased from 10Hz to 400Hz by 10Hz, and the measuring time of the square wave was changed from 96.695% to 96.765% by 0.005% while 1600 experiments were conducted. As a result, the frequency of the square wave maintained a stable area of potential-current within 320Hz and it was possible to measure the potential-current signal when calculating the measuring time within the frequency range of 96.7155%.

• Textile Coloration and Finishing
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• v.34 no.2
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• pp.102-108
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• 2022

The physicochemical properties of stainless steel fibers which were modified by oxygen plasma treatment were analyzed through microscopy and XPS analysis. The wettability of the surface of the stainless steel fiber was observed by measuring water contact angle to find out the effect of the plasma treatment time on the surface characteristics of the stainless steel fiber. In addition, in order to understand the effect of oxygen plasma treatment on the deterioration of the stainless steel fiber properties, the physical properties due to plasma treatment was investigated by measuring the weight reduction, tensile strength, elongation, tensile modulus of the stainless steel fibers according to the treatment time. As a result, the stainless steel fiber surface was etched by the oxygen plasma and the surface became more wettable by the introduction of hydrophilic functional groups. However the physical properties of the stainless steel fiber were not significantly deteriorated even if the surface of the stainless steel fiber made hydrophilic.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.1
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• pp.103-109
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• 2016

The performance of a multi-head, computerized combination scaling system to automatically identify a group of agricultural products having a total weight within the target range has been optimized to reduce the package cycle time of the merchandise. First, the structure of the scale was modified to enable faster measurement by enhancing the dynamic stability during the process. Second, the high frequency noise in the measured signal was eliminated by a high frequency filter to provide more accurate weight data. Finally, the algorithm to identify a group of products with a total weight within the target range was modified to enable a user to select an optimal number of scales. According to the experimental verifications, this modified system reduced the package cycle time significantly and also was accurate in measuring the total weight of the selected products.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.123.2-123.2
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• 2013

Etching endpoint detection with plasma impedance monitoring (PIM) is demonstrated for small area dielectric layers inductive coupled plasma etching. The endpoint is determined by the impedance harmonic signals variation from the I-V monitoring system. Measuring plasma impedance has been examined as a relatively simple method of detecting variations in plasma and surface conditions without contamination at low cost. Cluster analysis algorithm is modified and applied to real-time endpoint detection for sensitivity enhancement in this work. For verification, the detected endpoint by PIM and real-time cluster analysis is compared with widely used optical emission spectroscopy (OES) signals. The proposed technique shows clear improvement of sensitivity with significant noise reduction when it is compared with OES signals. This technique is expected to be applied to various plasma monitoring applications including fault detections as well as end point detection.