• Journal of Radiation Protection and Research
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• v.39 no.2
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• pp.81-88
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• 2014

Recently, a new imaging method, gamma vertex imaging (GVI), was proposed for the verification of in-vivo proton dose distribution. In GVI, the vertices of prompt gammas generated by proton induced nuclear interaction were determined by tracking the Compton-recoiled electrons. The GVI system is composed of a beryllium electron converter for converting gamma to electron, two double-sided silicon strip detectors (DSSDs) for the electron tracking, and a scintillation detector for the energy determination of the electron. In the present study, the modules of a charge sensitive preamplifier (CSP) and a shaping amplifier for the analog signal processing of DSSD were developed and the performances were evaluated by comparing the energy resolutions with those of the commercial products. Based on the results, it was confirmed that the energy resolution of the developed CSP module was a little lower than that of the CR-113 (Cremat, Inc., MA), and the resolution of the shaping amplifier was similar to that of the CR-200 (Cremat, Inc., MA). The value of $V_{rms}$ representing the magnitude of noise of the developed system was estimated as 6.48 keV and it was confirmed that the trajectory of the electron can be measured by the developed system considering the minimum energy deposition ( > ~51 keV) of Compton-recoiled electron in 145-${\mu}m$-thick DSSD.

• Journal of the Korean Chemical Society
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• v.41 no.2
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• pp.98-104
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• 1997

A simple, accurate and reproducible capillary electrophoresis(CE) assay has been developed for the determination of berberine, cinnamic acid, and glycyrrhizin which are used in traditional Korean medicinal preparations. Separation of these compounds was performed in 20 mM phosphate buffer(pH 7.5) and acetonitrile(75:25, v/v) using a bare fused silica capillary($57 cm{\times}75 {\mu}m$ i.d.) at 25$^{\circ}C$. With the electric field of 350 V/cm, the time needed for the separation of berberine, cinnamic acid and glycyrrhizin was within 13 min. Calibration curves were linear for 1∼100 ${\mu}g/mL$ berberine, 0.3∼100 ${\mu}g/mL$ cinnamic acid and 2.5∼100 ${\mu}g/mL$ glycyrrhizin. The ranges of relative standard deviations(n=5) for those samples were between 0.96∼2.35%. The limits of detection(S/N=3) for berberine, cinnamic acid and glycyrrhizin were 0.5, 0.1 and 2.0 ${\mu}g/mL$, respectively. The numbers of theoretical plates were 181,000(berberine), 88,000(cinnamic acid) and 169,000(glycyrrhizin), while they were 3,100∼4,800 in HPLC.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.5
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• pp.599-607
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• 2015

The purpose of this study is to reproduce long-term wave fields in coastal waters of Korea based on wave hind-casting modelling and discuss its applications. To validate wind data(NCEP, ECMWF, JMA-MSM), comparison of wind data was done with wave buoy data. JMA-MSM predicted wind data with high accuracy. But due to relatively longer period of ECMWF wind data as compared to that of JMA-MSM, wind data set of ECMWF(2001~2014) was used to perform wave hind-casting modelling. Results from numerical modelling were verified with the observed data of wave buoys installed by Korea Meteorological Administration(KMA) and Korea Hydrographic and Oceanographic Agency(KHOA) on offshore waters. The results agree well with observations at buoy stations, especially during the event periods such as a typhoon. Consequently, the wave data reproduced by wave hind-casting modelling was used to obtain missing data in wave observation buoys. The obtained missing data indicated underestimation of maximum wave height during the event period at some points of buoys. Reasons for such underestimation may be due to larger time interval and resolution of the input wind data, water depth and grid size etc. The methodology used in present study can be used to analyze coastal erosion data in conjunction with a wave characteristic of the event period in coastal areas. Additionally, the method can be used in the coastal disaster vulnerability assessment to generate wave points of interest.

• Journal of IKEEE
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• v.17 no.1
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• pp.1-9
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• 2013

The quantitative evaluation of DEM(Digital Elevation Map) is very important to the assessment of the effectiveness for the applied 3D image analysis technique. This paper presents a new quantitative evaluation method of 3D reconstruction process by using synthetic images. The proposed method is based on the assumption that a preacquired DEM and ortho-image should be the pseudo ground truth. The proposed evaluation process begins by generating a pair of photo-realistic synthetic images of the terrain from any viewpoint in terms of application of the constructed ray tracing algorithm to the pseudo ground truth. By comparing the DEM obtained by a pair of photo-realistic synthetic images with the assumed pseudo ground truth, we can analyze the quantitative error in DEM and evaluate the effectiveness of the applied 3D analysis method. To verify the effectiveness of the proposed evaluation method, we carry out the quantitative and the qualitative experiments. For the quantitative experiment, we prove the accuracy of the photo-realistic synthetic image. Also, the proposed evaluation method is experimented on the 3D reconstruction with regards to the change of the matching window. Based on the fact that the experimental result agrees with the anticipation, we can qualitatively manifest the effectiveness of the proposed evaluation method.

• Korean journal of communication and information
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• v.59
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• pp.116-137
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• 2012

What is 'nation' and 'nationalism?' What does 'korean nationalism' mean? And how is korean nationalism represented through a chain of films called 'the korean blockbuster films?' The purpose of this study is to answer to these questions. The characteristics of the korean blockbuster films have been studied for quite a long time and the researchers have agreed with the context about nationalism in a large sense. However, majority of the studies ends up in the journalistic or impressionistic criticism without any theoretical discussion. Few theoretical criticisms also have founded on the formation process of nation of the Western Europe and their nationalism. Hence I would like to add the discourse of korean nationalism and to seize more accurately the social/cultural/historical peculiarity of the korean blockbuster films. In addition, as non-nationalist narratives have recently emerged, korean blockbuster films are entering to the evolution process. On this, the significance of this study seems to exist in providing a cornerstone to the expected evolution theory of the korean blockbuster films by means of complementation and reestablishment of nationalism of their first generation. and , presenting socio-historical peculiarity of the Korean nation, are examined by the close textual analysis.

• Korean Journal of Crystallography
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• v.8 no.1
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• pp.38-47
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• 1997

A new weighing sensor for the automatic diameter control system of the crystal growth is developed in this study. This weighing sensor measures the frequency of the vibrating element which is lineally changing with respect to weight. The signal and the power of this system are transmitted without any physical contact, so that this sensor offers high accuracy and resolution. This system consists of a string, a sinusoidal wave generator, an automatic amplification adjusting circuit, signal transformers and a PCB. 4 kinds of programs are developed for checking DAC, weight calibration and controlling growth process. The measurements of the standard deviation and the resolution show $\pm0.10g$(measured at every second) and $5{\times}10^{-5}$, respectively, This weighing sensor is effective under high pres-sure of 200 atm, high temperature and vacuum condition. The weighing system can control the temperature in the accuracy of $\pm0.025^{\circ}C$ with the 'signal divider'. The optical quality single crystals of $(YGd)_3Sc_2Ga_3O_{12},\;Er-Y_3Sc_2Al_3O_{12},\;and\;Bi_{12}GeO_{20}$ have been grown by Czo-chralski method using this auto-diameter control system.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.2
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• pp.139-147
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• 2009

The gravity data collected and reserved in Korea is seriously biased in its distribution. That is, only the west-southern part of the peninsula including Chungcheong and Jeonla area has dense distribution while only a part is covered in Gyoungsang area. Especially, the low density of the gravity data in mountainous area basically limits the accuracy of the gravimetric geoid in Korea. As one of the solution to overcome the problem, an airborne gravity survey were conducted from Dec. 2008 $\sim$ Jan. 2009. In this study, free-air gravity anomaly derived from the airborne gravity data which has consistent quality are presented. The data processing for the airborne gravity is composed of several corrections of errors such as errors from gravity measurement, errors from flight dynamics, errors from GPS, and errors from time synchronization. We presented detailed explanations on the data processing with the final cross-over results. The free-air anomaly from airborne gravity finally shows the cross-over accuracy of 2.21mGal which reflects the precision of each track is 1.56mGal. It is expected that the result from this study will play a role as input data in precision geoid determination with ground and ship-borne gravity data after appropriate fusion process.

• Journal of the Korean Electrochemical Society
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• v.2 no.4
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• pp.227-231
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• 1999

Disposable, amperometric glucose sensor was constructed using platinised carbon paste electrode. The sensor response was studied by amperometry and cyclic voltammetry applying sample solutions on the strip-type electrode. Platinization of screen-printed carbon paste electrode effectively improved the electrochemical reversibility of a mediator and the analytical characteristics of the sensor. The heterogeneous rate constant for $[Fe(CN)_6]^{4-/3-}$ was $1.45\times10^{-2}cm{\cdot}s^{-1}$. An applied potential of 0.3V vs. Ag/AgCl resulted in the best selectivity for glucose. The apparent Michaelis-Menten constant for glucose on the strip sensor, $K_m^{app}$, was 24.5 mM. To evaluate the analytical performance of the glucose sensor strip, a correlation study was performed with the NOVA S.P, Ultra M analyzer for 30 serum samples containing $80\~297mg/dL$ of glucose: the correlation coefficient value was 0.983. It can be seen that the strip sensor has satisfactory precision and accuracy.

• Journal of KIISE:Software and Applications
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• v.31 no.4
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• pp.447-456
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• 2004

Information extraction is a process of recognizing and fetching particular information fragments from a document. In order to extract information uniformly from many heterogeneous information sources, it is necessary to produce information extraction rules called a wrapper for each source. Previous methods of information extraction can be categorized into manual wrapper generation and automatic wrapper generation. In the manual method, since the wrapper is manually generated by a human expert who analyzes documents and writes rules, the precision of the wrapper is very high whereas it reveals problems in scalability and efficiency In the automatic method, the agent program analyzes a set of example documents and produces a wrapper through learning. Although it is very scalable, this method has difficulty in generating correct rules per se, and also the generated rules are sometimes unreliable. This paper tries to combine both manual and automatic methods by proposing a new method of learning information extraction rules. We adopt the scheme of supervised learning in which a user-interface agent is designed to get information from the user regarding what to extract from a document, and eventually XML-based information extraction rules are generated through learning according to these inputs. The interface agent is used not only to generate new extraction rules but also to modify and extend existing ones to enhance the precision and the recall measures of the extraction system. We have done a series of experiments to test the system, and the results are very promising. We hope that our system can be applied to practical systems such as information-mediator agents.

• The Journal of Engineering Geology
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• v.24 no.1
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• pp.53-67
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• 2014

Numerical modeling is commonly used to reproduce the physical phenomena of dam-break and to compile resulting flood hazard maps. The accuracy of a dam-break model depends on the physical structure that describes the volume of storage, breach formation and progress, input variables, and model parameters. Model input and parameters are subjective in that they are prescribed; hence, caution is needed when interpreting the results. This study focuses on three parameters (breach degree ${\theta}$, shape factor P, and collapse rate k) used when the dam-break model is coupled with FLO-2D (a two-dimensional flood simulation model) to estimate flood coverage and depth etc. The results show that the simulation is sensitive to the shape factor P and the collapse rate k but not to the breach degree ${\theta}$. This study will contribute to reducing flood damage from dam-break disasters in the future.