• The Journal of the Acoustical Society of Korea
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• v.26 no.6
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• pp.301-305
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• 2007

In this paper, we propose a simple algorithm for detecting underwater transient signals on the fact that the frequency range of underwater transient signals is similar to audio frequency. For this, we use a preprocessing module of EVRC speech codec that is the standard speech codec of the mobile communications. If a signal is entered into EVRC noise suppression module, we can get some parameters such as the update flag, the energy of each channel, the noise suppressed signal, the energy of input signal, the energy of background noise, and the energy of enhanced signal. Therefore the energy of the enhanced signal that is normalized with the energy of the background noise is compared with the pre-defined detection threshold, and then we can detect the transient signal. And the detection threshold is updated using the previous value in the noisy period. The experimental result shows that the proposed algorithm has $0{\sim}4% error rate in the AWGN or the colored noise environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.12C
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• pp.1133-1143
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• 2005

In this paper, we propose an enhanced two-step search scheme for rapid and reliable signal acquisition in UWB systems under multipath channels. The proposed TSS-LS (Two-Step Search scheme with the Linear search based Second step) achieves rapid acquisition performance comparable to the conventional TSS-BS (Two-Step Search scheme with the Bit reversal search based Second step) already proposed by the authors, based on the single-dwell search with two-step thresholds and search windows. However, unlike the TSS-BS which employs the bit reversal search in the second step, the proposed TSS-LS utilizes the linear search in the second step to improve the reliability of signal acquisition. Simulation results with multipath channel models by IEEE 802.15.3a show that the two-step search schemes for the UWB signal acquisition can achieve sig nificant reduction of the required mean acquisition time as compared to general search schemes. In addition, we observe that the proposed TSS-LS achieves quite good bit error rate performance for large signal-to-noise ratios, which is favorably comparable to the case of ideal perfect timing.

• Investigative Magnetic Resonance Imaging
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• v.14 no.2
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• pp.103-114
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• 2010

Purpose : To generate a Korean specific brain template, especially in patients with Alzheimer's disease (AD) by optimizing the voxel-based analysis. Materials and Methods : Three-dimensional T1-weighted images were obtained from 123 subjects who were 43 cognitively normal subjects and patients with 44 mild cognitive impairment (MCI) and 36 AD. The template and the corresponding aprior maps were created by using the matched pairs approach with considering differences of age, gender and differential diagnosis (DDX). We measured several characteristics in both our and the MNI templates, including in the ventricle size. Also, the fractions of gray matter and white matter voxels normalized by the total intracranial were evaluated. Results : The high resolution template and the corresponding aprior maps of gray matter, white matter (WM) and CSF were created with the voxel-size of $1{\times}1{\times}1\;mm$. Mean distance measures and the ventricle sizes differed between two templates. Our brain template had less gray matter and white matter areas than the MNI template. There were volume differences more in gray matter than in white matter. Conclusion : Gray matter and/or white matter integrity studies in populations of Korean elderly and patients with AD are needed to investigate with this template.

• Korean Journal of Remote Sensing
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• v.14 no.1
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• pp.53-68
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• 1998

Observation of hydrometeors' behavior in the atmosphere is important to understand weather and climate. By conventional observations, we can get the distribution of water vapor at limited number of points on the earth. In this study, the precipitable water has been estimated from the split window channel data on GMS-5 based upon the technique developed by Chesters et al.(1983). To retrieve the precipitable water, water vapor absorption parameter depending on filter function of sensor has been derived using the regression analysis between the split window channel data and the radiosonde data observed at Osan, Pohang, Kwangiu and Cheju staions for 4 months. The air temperature of 700 hPa from the Global Spectral Model of Korea Meteorological Administration (GSM/KMA) has been used as mean air temperature for single layer radiation model. The retrieved precipitable water for the period from August 1996 through December 1996 are compared to radiosonde data. It is shown that the root mean square differences between radiosonde observations and the GMS-5 retrievals range from 0.65 g/$cm^2$ to 1.09 g/$cm^2$ with correlation coefficient of 0.46 on hourly basis. The monthly distribution of precipitable water from GMS-5 shows almost good representation in large scale. Precipitable water is produced 4 times a day at Korea Meteorological Administration in the form of grid point data with 0.5 degree lat./lon. resolution. The data can be used in the objective analysis for numerical weather prediction and to increase the accuracy of humidity analysis especially under clear sky condition. And also, the data is a useful complement to existing data set for climatological research. But it is necessary to get higher correlation between radiosonde observations and the GMS-5 retrievals for operational applications.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.3
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• pp.255-263
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• 2021

Soybean extract is known to play an important role in preventing and treating diseases associated with aging, cancer, obesity, and cardiovascular disease. A recent has revealed that soybean extract has a potent effect on hair growth in in vitro, in vivo, and clinical studies. Recently, it has been reported that their fermented extracts exhibit numerous and high efficacy, as compared to general extracts. However, the underlying mechanisms that induce hair growth after using fermented soybean extract are not well understood. The present study aimed to determine the effects of fermented Jeju soybean (FJS) extract on hair growth, with a focus on the underlying mechanisms similar to those of minoxidil. We conducted in vitro and ex vivo investigations and clinical studies. FJS extract enhanced dermal papilla cell proliferation, VEGF levels, and potassium channel opening. Moreover, it promoted human hair follicle elongation. These effects were comprehensively demonstrated in the clinical results, in which FJS extract-containing shampoo improved hair density after 24 weeks of utilization. Collectively, the results of this study demonstrate that FJS extract promotes hair growth and inhibits hair loss through a mechanism similar to that of minoxidil in hair follicles.

• Journal of Korean Classical Literature and Education
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• no.39
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• pp.137-180
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• 2018

This article examines the constitutional characteristics of the works in the "Shinbi Apartment" (Mysterious Apartment) series produced by Tooniverse, a domestic animation channel, and considers the meaning of the contents of the ghoststory (鬼神談). The "Shinbi Apartment" series is a horror animation for children. It was produced for the first time in Korea and recorded high ratings. Additionally, it is different from Japanese horror animations that were dubbed and broadcast in Korea in terms of composition and narrative direction, and it succeeds in the form and direction of the traditional Korean ghost story. "Shinbi Apartment - The Secret of Ghost Ball" enriches narrative stories by embracing the structure of the "female ghost story" in traditional ghost stories while following the form of ghosts that suddenly pop up in the daily routines of contemporary ghost stories. The ghost's shape, which has a bizarre and unpredictable aspect, embodies the ghost as the object of fear that modern horror stories intend. However, it does not stop there, but puts the attention on the hero who focuses on the emerging ghost and listens and communicates with it, placing the emphasis of the story on communication, understanding, forgiveness, and reconciliation. The structure and contents of the unique story of "The Secret of Ghost Ball" contribute to the transformation of the ghost into a subject of friendliness and entertainment, not merely as one of shock, fear, and anxiety. Additionally, as the concept of "child" is being created, the custom of modernity, which deals with the story of ghosts in the dimension of teaching and edification, is also manifested in "The Secret of Ghost Ball." In other words, through the figure of the devil, it is to continue the lesson of the story by revealing the adventure, the courage necessary for the "child," and the boundaries for substance and appearance. The "Shinbi Apartment" series has also contributed to the success of ghosts as commercial contents. The structure of the story and its characters have been actively used as educational tools and toys for children. It can be said that ghost culture contributed to this popularization by establishing a base for enjoying ghosts for amusement and entertainment.