• The Korean Journal of Archival Studies
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• no.43
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• pp.5-42
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• 2015

Korean wave 3.0 is focused on 'K-Culture' which includes traditional culture, cultural art as well as existing culture contents as a keyword. It considers everything about Korean culture as materials of Korean wave culture contents. Since Korean wave culture contents reflect contemporary social aspect, it needs to preserve those contents as archives and records which have the important value of evidence. With this social environment, this study aims to implement RMS based on AtoM that manages various kinds of Korean wave culture contents through analysis of management situation of those materials. Recently, it is in progress individually to manage them through organizations dealing with korean cultures such as K-Pop, K-Food, K-Movie. However, it has problems in accumulating information and reproducing high quality contents because of lack of coordination among organizations. To solve the problems, this study proposed RMS based on open source software Access to Memory(AtoM) for managing and recording Korean wave culture contents. AtoM provides various functions for managing records and archives such as accumulation, classification, description and browsing. Furthermore AtoM is for free as open source software and easy to implement and use. Thus, this study implemented RMS based on AtoM to methodically manage korean wave culture contents by functional requirements of RMS. Also, this study considered contents relating K-Food as an object to collect, classify, and describe. To describe it, this study selected ISAD(G) standard.

• The Korean Journal of Archival Studies
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• no.70
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• pp.85-117
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• 2021

The purpose of this study is to investigate and analyze the current status of unit tasks, unit task operation, and record management problems used by local governments, and to present improvement measures using text-based big data technology based on the implications derived from the process. Local governments are in a serious state of record management operation due to errors in preservation period due to misclassification of unit tasks, inability to identify types of overcommon and institutional affairs, errors in unit tasks, errors in name, referenceable standards, and tools. However, the number of unit tasks is about 720,000, which cannot be effectively controlled due to excessive quantities, and thus strict and controllable tools and standards are needed. In order to solve these problems, this study developed a system that applies text-based analysis tools such as corpus and tokenization technology during big data analysis, and applied them to the names and construction terms constituting the record management standard. These unit task operation support tools are expected to contribute significantly to record management tasks as they can support standard operability such as uniform preservation period, identification of delegated office records, control of duplicate and similar unit task creation, and common tasks. Therefore, if the big data analysis methodology can be linked to BRM and RMS in the future, it is expected that the quality of the record management standard work will increase.

• Korean Journal of Optics and Photonics
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• v.32 no.6
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• pp.314-322
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• 2021

A reflecting telescope consists of a concave primary mirror and a convex secondary mirror. The primary mirror is easy to measure, because it converges the beam from an interferometer, while the secondary mirror diverges the beam and so is not easy to measure, even though it is smaller than the primary mirror. In addition, the Korsch-type telescope uses the central area of the secondary mirror, so that the entire area of the secondary mirror needs to be measured, which the classical Hindle test cannot do. In this paper, we propose a double-stitching method that combines two separate area measurements: the annular area, measured using the Hindle stitching method, and the central area, measured using a spherical wave from the interferometer. We test the surface error of a convex asphere that is 202 mm in diameter, with 499 mm for its radius of curvature and -4.613 for its conic constant. The surface error is calculated to be 19.5±1.3 nm rms, which is only 0.7 nm rms different from the commercial stitching interferometer, ASI. Also, the two results show a similar 45° astigmatism aberration. Therefore, our proposed method is found to be valuable for testing the whole area of a convex asphere.

• The Korean Journal of Archival Studies
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• no.57
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• pp.235-279
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• 2018

Electronic records produced by central administrative agencies are transferred to the National Archives of Korea. In the absence of defects or errors in electronic records, it is a proof that the government's electronic records management system is operating normally. Various problems have been found in this process, and there still remain problems to be solved. At the heart of it is a standard records management system, which has been continuously improved. In this paper, I introduce the functional improvement of the record management functions of the standard records management system. Among them, the important matters describe the background and reason for the improvement. In addition, the direction of development of the standard records management system was examined in terms of recognition conversion of recordkeepers, strengthen collaboration between recordkeepers and developers, improving records management metadata quality, linking related systems, automating records management, and IT environment change.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.1
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• pp.1-10
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• 2024

The radio propagation characteristics of the 6, 10, and 17 GHz frequency bands in multiple paths in an indoor lobby environment were analyzed. The line-of-sight (LOS) and non-LOS (NLOS) paths were measured from a distance of 2-16 m (0.5 m intervals) from the transmitting to the receiving antenna positions. For basic transmission losses, three parameters were compared using the floating intercept path loss model corresponding to the path. For a root mean square delay spread, the measurement results were compared for cumulative probabilities of 10, 50, and 90%. Propagation loss and propagation delay occurred in all measured frequencies owing to the existence of pillars and an unusual lobby structure. Thus, a measurement scenario for an indoor lobby environment and the provision of standard measurement data was proposed. The results may facilitate research on the radio propagation characteristics of 5G and millimeter-wave bands in indoor lobby environments with various structures.

• Economic and Environmental Geology
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• v.48 no.6
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• pp.451-465
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• 2015

The free-air anomalies are computed using a data set from various types of gravity measurements in the Korean Peninsula area. The gravity values extracted from the Earth Gravitational Model 2008 are used in the surrounding region. The upward continuation technique suggested by Dragomir is used in the computation of the external free-air anomalies at various altitudes. The integration radius 10 times the altitude is used in order to keep the accuracy of results and computational resources. The direct geodesic formula developed by Bowring is employed in integration. At the 1-km altitude, the free-air anomalies vary from -41.315 to 189.327 mgal with the standard deviation of 22.612 mgal. At the 3-km altitude, they vary from -36.478 to 156.209 mgal with the standard deviation of 20.641 mgal. At the 1,000-km altitude, they vary from 3.170 to 5.864 mgal with the standard deviation of 0.670 mgal. The predicted free-air anomalies at 3-km altitude are compared to the published free-air anomalies reduced from the airborne gravity measurements at the same altitude. The rms difference is 3.88 mgal. Considering the reported 2.21-mgal airborne gravity cross-over accuracy, this rms difference is not serious. Possible causes in the difference appear to be external free-air anomaly simulation errors in this work and/or the gravity reduction errors of the other. The external gravity field is predicted by adding the external free-air anomaly to the normal gravity computed using the closed form formula for the gravity above and below the surface of the ellipsoid. The predicted external gravity field in this work is expected to reasonably present the real external gravity field. This work seems to be the first structured research on the external free-air anomaly in the Korean Peninsula area, and the external gravity field can be used to improve the accuracy of the inertial navigation system.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.11
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• pp.828-833
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• 2018

It is well known that reflected waves and resonance affect phase distortion. In addition, phase delay can be distorted by antenna impedance. In this study, we analyze the phase delay variation caused by the antenna impedance, considering mutual coupling effects. In addition, we confirm the beam steering characteristics. When was -10 dB and -7 dB, the maximum phase delay error was $18.5^{\circ}$ and $26.5^{\circ}$, respectively. The Monte Carlo simulation with an eight-element linear array antenna demonstrated that the RMS error of the beam steering angle ranged from $0.19^{\circ}$ to $0.4^{\circ}$, and the standard deviation ranged from $0.14^{\circ}$ to $0.33^{\circ}$ when the beam steering angle was in the range of $0^{\circ}$ to $30^{\circ}$, with the uniformly distributed phase error of $18.5^{\circ}$ and $26.5^{\circ}$. The side lobe level increased from 0.74 dB to 1.21 dB by the phase error from the theoretical value of -12.8 dB, with a standard deviation of 0.31 dB to 0.51 dB. This is verified by designing an eight-element spiral array antenna.

• Korean Journal of Optics and Photonics
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• v.34 no.3
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• pp.117-123
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• 2023

The size of an optical surface can significantly affect the performance of an optical system, and high spatial frequency errors have a greater impact. Therefore, it is crucial to measure the surface figure error with high frequency. To address this, a new method called rotational prism stitching interferometer (RPSI) is proposed in this study. The RPSI is a type of stitching interferometer that enhances spatial resolution, but it differs from conventional stitching interferometers in that it does not require the movement of either the mirror tested or the interferometer itself to obtain sub-aperture interferograms. Instead, the RPSI uses a beam expander and a rotating Dove prism to select particular sub-apertures from the entire aperture. These sub-apertures are then stitched together to obtain a full-aperture result proportional to the square of the beam expander's magnification. The RPSI's effectiveness was demonstrated by measuring a 40 mm diameter spherical mirror using a three-magnification beam expander and comparing the results with those obtained from a commercial interferometer. The RPSI achieved surface testing results with nine times higher sampling density than the interferometer alone, with a small difference of approximately 1 nm RMS.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.10
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• pp.699-705
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• 2001

Six types of planar thermal converters from TC 1 to TC 6 were designed and fabricated for the purpose of being used as practical standards to alternating current. The respective voltage responses in air and in a vacuum of TC 6, which has the smallest thermal loss, were about 4.03mV/mW and about 6.38 mV/mW. Thermal time constant of TC 6, which has also the smallest heater thermal inertia, was about 8 ms. The respective variations of AC-DC voltage and current transfer errors from sample to sample, which were measured by FRDC(fast reversed DC) method, were about $\pm$0.41 ~$\pm$0.85 ppm and about $\pm$0.15~$\pm$1.16 ppm in the frequent range of 40 Hz~10 KHz with appling 1 V and 5 mA rms sine waves to the converters. All converters investigated exhibited sufficiently low AC-DC transfer errors to be used as practical standards.

• Journal of the Korean Society of Radiology
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• v.10 no.8
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• pp.597-602
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• 2016

Recent clinical field utilizes the aluminium filter in order to reduce the low-energy photons. However, the usage of the filter can cause adverse effect on the image quality because of the scattered dose that is generated by X-ray hardening phenomenon. Further, usage of filter with improper thickness can be a reason of dose creep phenomenon where unnecessary exposure is generated towards the patient. In this study, the author evaluated the RMS and the RSD analysis in order to have a quantitative evaluation for the effect of forward scattering dose by the filter on the image. as a result of the study, the FSR and the RSD was increased together with the increasing of thickness of the filter. In this study the RSD means the standard deviation of the mean value is relatively size. It can be understood that the signal-to-noise ratio decreases when the average value is taken as a signal and the standard deviation is judged as a noise. The signal-to-noise ratio can understanding as index of resolution at image. Based on these findings, it was quantitatively verified that there is a correlation of the image quality with the FSR by using an additional filter. The results, a 2.5 mmAl which is as recommended by NCRP in the tube voltage of 70 kVp or more showed the 14.6% on the RSD when the filter was not in used. these results are considered able to be utilized as basic data for the study about the filter to improve the quality of the image.