• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1656-1658
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• 1998

This paper deals with a measurement system of a distance between lightning strokes and observatory station and spectrum analysis of electric fields radiated from lightning discharges. The distance measurement system, which consists of a loop type magnetic field sensor, a microphone and one chip microprocessor, is connected to a personal computer through RS232 port to acquire and process the data. This system is to use a difference of propagation velocity between an electromagnetic wave and a sonic wave produced by lightning discharge. Also, an electric field waveform and a frequency spectrum were investigated by an electric field measurement system with a hemisphere antenna and a spectrum analyzer with a biconical antenna and a log-periodic antenna, respectively. The results would be used as a basic reference to protect the power systems and electric circuits from lightning overvoltages.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.499-502
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• 1998

Most popular disk block replacement polices are LRU(Least Recently Used)policy and LFU(Least Frequently Used)policy. The LRU policy replaces blocks according to the most recent reference without considering the frequency of reference. The LFU policy replaces blocks according to the frequency of reference without considering the recently of the reference. In this thesis, a policy called LFR(least Frequently Use & Not Used Recently) disk block replacement policy is presented. The LFR policy subsumes the LFU policy and the NUR policy. The spectrum of the LFR policy exists between the LFU policy and the NUR policy because we co give different weight to each reference of a block. The implementation shows LFR policy outperforms the previously implemente LRU policy.

• Journal of Biomedical Engineering Research
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• v.13 no.1
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• pp.65-68
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• 1992

In the present study, an attempt is presented to define the power spectrum of the saccades recorded in man by using bitemporal EOG. In this study, it was found that the estimated bandwidth of the spectrum of the saccades decreases for increasing saccade amplitude. This study could show a reference value about the minimum bandwidth needed to correctly measure even small saccades by bitemporal EOG. It also showed that EOG method is not appropriate to measure microsaccade.

• Journal of Ginseng Research
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• v.35 no.4
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• pp.487-496
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• 2011

Good manufacturing practice (GMP)-based quality control is an integral component of the common technical document, a formal documentation process for applying a marketing authorization holder to those countries where ginseng is classified as a medicine. In addition, authentication of the physico-chemical properties of ginsenoside reference materials, and qualitative and quantitative batch analytical data based on validated analytical procedures are prerequisites for certifying GMP. Therefore, the aim of this study was to propose an authentication process for isolated ginsenosides $Rb_1$ and $Rg_1$ as reference materials (RM) and for these compounds to be designated as RMs for ginseng preparations throughout the world. Ginsenoside $Rb_1$ and $Rg_1$ were isolated by Diaion HP-20 adsorption chromatography, silica gel flash chromatography, recrystallization, and preparative HPLC. HPLC fractions corresponding to those two ginsenosides were recrystallized in appropriate solvents for the analysis of physico-chemical properties. Documentation of the isolated ginsenosides was made according to the method proposed by Gaedcke and Steinhoff. The ginsenosides were subjected to analyses of their general characteristics, identification, purity, content quantitation, and mass balance tests. The isolated ginsenosides were proven to be a single compound when analyzed by three different HPLC systems. Also, the water content was found to be 0.940% for $Rb_1$ and 0.485% for $Rg_1$, meaning that the net mass balance for ginsenoside $Rb_1$ and $Rg_1$ were 99.060% and 99.515%, respectively. From these results, we could assess and propose a full spectrum of physicochemical properties for the ginsenosides $Rb_1$ and $Rg_1$ as standard reference materials for GMP-based quality control.

• Journal of Photoscience
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• v.9 no.2
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• pp.460-462
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• 2002

Absorption spectra of biological specimens in the soft X-ray region have been presented with special reference to the XANES (X-ray absorption Near Edge Structure) of constituent elements. Absorption spectrum in this wavelength region is characterized by the absorption edges from which elemental content could be derived. In addition, XANES has a characteristic profile for chemical environment around the element such as chemical bond. Using the specific absorption peak we can assign not only the chemical bond but also molecules having such a chemical bond. In the present paper, absorption spectrum of DNA was measured in the wavelength range from 1.5nm to 5nm. Spectrum of Chinese Hamster Ovary (CHO) cells was compared with the DNA spectrum. XANES were distinct at the K absorption edges of major elements, C, N and O. In the spectrum of the cells prominent peaks at the L absorption edge of minor element Ca were also detectable. XANES profiles in small local areas in a cell could also be measured in combination with X-ray microscopy. These give information about local chemical environment in a cell. XANES at the phosphorus K absorption edge in a human HeLa cell was successfully obtained corresponding to a sharp and intensive XANES peak of DNA.

• Clinical and Experimental Pediatrics
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• v.63 no.1
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• pp.8-13
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• 2020

Autism spectrum disorder is a common neurodevelopmental disorder with an unknown etiology. The correlation between neonatal jaundice and the risk of developing autism spectrum disorder was investigated previously. Some studies showed significant associations, whereas others demonstrated no association. In this meta-analysis, we pooled the results of observational studies to examine the association between neonatal jaundice and the risk of autism spectrum disorder among children. We identified all studies published through April 2018 by conducting a literature search using Web of Science, PubMed, and Scopus databases as well as the reference lists of the retrieved studies. The pooled odds ratios (ORs), rate ratio (RR), and their 95% confidence intervals (CIs) were calculated as random effect estimates of association among studies. We conducted a subgroup analysis to explore any potential sources of intergroup heterogeneity. The pooled estimates of OR and RR showed a considerable correlation between neonatal jaundice and ASD among children (OR, 1.35; 95% CI, 1.02-1.68) and (RR, 1.39; 95% CI, 1.05-1.74). A larger effect size was shown in the pooled estimated crude OR than in the adjusted OR (1.75 [0.96-2.54] vs. 1.19 [1.07-1.30]). This study showed that neonatal jaundice may be associated with ASD and may increase the risk of ASD among children.

• Earthquakes and Structures
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• v.3 no.2
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• pp.141-168
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• 2012

The Retrofit Yield Spectrum (RYS) is a new spectrum-based device that relates seismic demand of a retrofitted structure with the fundamental design parameters of the retrofit. This is obtained from superposition of Yield Point Spectra with design charts that summarize in pertinent spectrum-compatible coordinates the attributes of a number of alternative retrofit scenarios. Therefore, once the requirements for upgrading a given structure have been determined, the RYS enable direct insight of the sensitivity of the seismic response of the upgraded structure to the preliminary design decisions made while establishing the retrofit plan. By virtue of their spectrum-based origin, RYS are derived with reference to a single mode of structural vibration; a primary objective is to control the contribution of this mode in the retrofit design so as to produce a desirable distribution of damage at the ultimate limit state by removing soft storey formations and engaging the maximum number of structural members in deformation, in response to the input motion. Calculations are performed with reference to the yield-point, where secant stiffness is proportional to the flexural strength of reinforced concrete members. Derivation and use of the Retrofit Yield Spectra (RYS) refers to the seismic demand expressed either in terms of spectral acceleration, spectral displacement or interstory drift, at yield of the first storey. A reinforced concrete building that has been tested in full scale to a sequence of simulated earthquake excitations is used in the paper as a demonstration case study to examine the effectiveness of the proposed methodology.

• Journal of the Korean Society of Radiology
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• v.18 no.5
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• pp.499-508
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• 2024

As a result of analyzing the spectrum using a ¹H-NMR spectrometer and a ¹H-NMR spectrum prediction program for Visipaque contrast agent, the molecular structure positions in the 2.18 ppm and 2.17 ppm regions were found to be different from each other. The 2.25 ppm and 2.34 ppm regions did not appear in the spectrum analysis using the spectrometer, but did appear in the analysis using the prediction program. In addition, the 2.58 ppm region appeared in the spectrum analysis using the spectrometer, but did not appear in the analysis using the prediction program. The 4.42 ppm region did not appear in the spectrum analysis using the spectrometer, but did appear in the analysis using the prediction program. In addition, the 5.61 ppm region appeared in the spectrum analysis using the spectrometer, but did not appear in the analysis using the prediction program. Based on this, it is thought that if we analyze it using the prediction program as a reference, we will be able to identify the chemical structure more clearly.

• Journal of the Korea Institute of Military Science and Technology
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• v.3 no.1
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• pp.85-91
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• 2000

Underwater sensor accuracy test which measures the detection range and bearing accuracies of sonar simulates sonar transmitting ping and underwater radiating noise of target vessels. In this test, because the position of sonar target is the reference position of test, the sonar target position should be precisely estimated. Hence, this paper suggests to apply USBL algorithm which adopts cross phase spectrum of received sensor signals, and presents its performance by range and bearing estimation simulations. As a result of simulations, suggested algorithm shows good accuracy for underwater sensor accuracy test near 5㏈ SNR.

• Journal of The Korean Astronomical Society
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• v.37 no.2
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• pp.87-90
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• 2004

Spectrophotometry of the night sky over Mount Bohyun is presented for the nearly entire visible wavelengths of $3600{\~}$8600{\AA}$. The data was obtained under moonless clear sky in February 2004 with the 1.8-m telescope and the long slit spectrograph. The sky spectrum shows a number of strong emission lines originated from light pollution, especially due to high pressure sodium lamps. When compared to the night sky of Kitt Peak, our sky continuum is 1 to 2 magnitude brighter at all wavelengths, the worst being around the broad emission region near 6000${\AA}$. The night sky spectrum presented here with almost complete line identifications is a useful reference for arc-independent wavelength calibrations to check the gravity flexure of the spectrograph and the wavelength shift between FeNeArHe arc frames and science frames.