• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.3
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• pp.321-339
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• 2014

This paper concerns the development of a knowledge-based tunnel design system within the framework of artifical neural networks(ANNs). The system is aimed at expediting a routine tunnel design works such as computation of segment lining body forces and stability analysis of selected cross section. A number of sub-modules for computation of segment lining body forces and stability analysis were developed and implemented to the system. It is shown that the ANNs trained with the results of 3D numerical analyses can be generalized with a reasonable accuracy, and that the ANN based tunnel design concept is a robust tool for tunnel design optimization. The details of the system architecture and the ANNs development are discussed in this paper.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.4
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• pp.155-164
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• 2005

The coast has been known as very vulnerable area. This area has nature disasters such as typhoon, tidal wave, flood and storm almost every year. In this study, coast vulnerable area information management system was developed to manage the coastal facilities and vulnerable area through Web GIS. This system is able to visualize the damage area and support the official work related to coast as efficient DSS(Decision Supporting System). Moreover, the foundation for domestic coast information management is expected by acquiring less cost and time. For this, GIS DB was first constructed by acquiring damage factor data such as typhoon, tidal wave, flood and storm. Then GIS analysis methods and high resolution satellite images are used to possibly present the results of retrieve as table, map, graph, inundation simulation in real time.

• Journal of the Earthquake Engineering Society of Korea
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• v.20 no.4
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• pp.223-234
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• 2016

To investigate earthquake responses of structures with basements affected by soil deposits, centrifuge tests were performed using an in-flight earthquake simulator. The test specimen was composed of a single-degree-of-freedom structure model, a basement and sub-soil deposits in a centrifuge container. The test parameters were the dynamic period of the structure model, boundary conditions of the basement, existence of soil deposits, centrifugal acceleration level, and type and level of input earthquake accelerations. When soil deposits did not exist, the earthquake responses of the structures with fixed basement were significantly greater than those of the structure without basement. Also, the earthquake responses of the structures with the fixed basement surrounded by soil deposits were amplified, but the amplifications were smaller than those of the structures without basement. The earthquake responses of the structures with the half-embedded basement in the soil deposits were greater than those estimated by the fixed base model using the measured free-field ground motion. The test showed that the basement and the soil deposit should be simultaneously considered in the numerical analysis model, and the stiffness of the half-embedded was not effective.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.1
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• pp.43-50
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• 2005

We proposed a method for embedding coded binary data into EZW bitstreams and extracting embedded data from EZW bitstreams using the traditional EZW decoder. EZW coder have two passes. The first pass, the dominant pass have four symbols, P, N, IZ, ZTR. The second pass is sub-ordinary pass which specifies the value of symbol. In the proposed methods, we use ZTR symbol in the dominant pass. We embed watermark into ZTR symbol in the highest frequency band which original image is transferred by wavelet transform. The proposed digital watermarking method shows good properties for robustness in the low bit rate. Accordingly, based on the proposed digital watermarking, video and 3D image watermarking will become a new area for research in the near future.

• The Journal of the Korea Contents Association
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• v.20 no.4
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• pp.385-395
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• 2020

The dance area is less demanding than the supply, so it is not able to properly utilize talented people. If the university based dance research center is activated in this field, it can be an alternative by actively interacting with the residents of the community. Therefore this study was surveyed by specialists on invigorating dance institutes by applying new industrial development. Since then, workers were requested to evaluate importance and urgency of 23 questionnaires collected. As a result, the most important item was program development, and the most urgent was financial support. The first ranked sub-item of program development was organization of R&D cost(importance) and recruitment of professionals(urgency). Regarding financial support, it was budget increase and eligibility expansion of staff cost(importance) and subdivision and extended support for labor cost.

• International Journal of Internet, Broadcasting and Communication
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• v.9 no.2
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• pp.70-77
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• 2017

Where there are all the flowers, the songs of all kinds of insects and birds are put in, the sunshine and shadows flicker The forest through which the water sound flows is an optimum resting space. All living creatures in these spaces will awaken the five senses of humans and perhaps turn the sensibility index (EQ). The forest meditation in the forest, which can be an optimal shelter for the people who need it, needs to feel the reverence of nature, to refine emotions, to be a self-reflection, to have a mind to respect, Have an important meaning. In this paper, we tried to consider the cause of the influence of forest sounds on human hearing from the acoustical aspect. The type of sound source of forest was divided into four seasons of spring, summer, autumn, winter. And the change in the duration of the sound during the four seasons, so that the general characteristics of the sounds of the four seasons are as follows: It can be seen that the change in the ratio of sub-band energy is almost equal to the change in dB in frequency of the equal-light curve. To compare this phenomenon, the criterion for changing the sound duration of each forest is natural The main forms of the luminance curve, such as the change in the duration of the white signal in the sound, are determined by the minimum, maximum audible frequency and the most sensitive frequency band, and the auditory characteristics of the other three inflection points Determines the overall shape of the equal-light curve.

• Journal of The Korean Astronomical Society
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• v.51 no.4
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• pp.89-110
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• 2018

Active Galactic Nucleus (AGN) variability can be used to study the physics of the region in the vicinity of the central black hole. In this paper, we investigated intra-night optical variability of AGN in the COSMOS field in order to understand the AGN instability at the smallest scale. Observations were performed using the KMTNet on three separate nights for 2.5 to 5 hours at a cadence of 20 to 30 min. We find that the observation enables the detection of short-term variability as small as ~ 0.02 and 0.1 mag for R ~ 18 and 20 mag sources, respectively. Using four selection methods (X-rays, mid-infrared, radio, and matching with SDSS quasars), 394 AGN are detected in the $4deg^2$ field of view. After differential photometry and ${\chi}^2$-test, we classify intra-night variable AGN. The fraction of variable AGN (0-8%) is statistically consistent with a null result. Eight out of 394 AGN are found to be intra-night variable in two filters or two nights with a variability level of 0.1 mag, suggesting that they are strong candidates for intra-night variable AGN. Still they represent a small population (2%). There is no sub-category of AGN that shows a statistically significant intra-night variability.

• Journal of Nutrition and Health
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• v.36 no.6
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• pp.646-652
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• 2003

This study was performed to determine the iron status of the adolescent Korean girls before and after menarche. The 101 subjects aged 11-13 years who attending in an elementary school in Mokpo were recruited. They were divided into pre-menarche (A) group or post-menarche (B) group based on their menstruation status. The latter subjects were sub-divided into one of the four groups according to the times of their menstruation B-I( $\geq$ 3 times), B-II (4-6 times), B-III (7-9 times) or B-W ( $\geq$ 10 times). In the total subjects, dietary iron intake, 11.3 mg/day, was below the Korean RDA for iron, the percentage of heme iron to total iron intake, 15%, and the bioavailability of dietary iron, 12.3%, seemed to be low. And their body iron storage, 140.8 mg, seemed to be insufficient. However, they tended to meet body's iron requirement in the cell level. Red blood cell number (RBC), hematocrit (Hct), and hemoglobin (Hb) level in the total subjects were 4.5 1012/I, 39.3%, and 13.0 g/㎗, respectively. The subjects in B group had lower (p<0.05) RBC and Hct compared to those in A group and the prevalence of iron-deficiency anemia tended to be high. Serum iron, ferritin, and soluble transferrin receptor (sTfR) and sTfR:ferritin ratio were 86.7 $\mu\textrm{g}$/d, 17.6 $\mu\textrm{g}$/l, 3.58 mg/1, and 230, respectively. Those four indices were not significantly different among the groups. The results of this study imply that, although there a tendency to affect negatively iron status, menstrual blood loss in adolescent females does not deteriorate obviously their iron status during the relatively short period up to 1 you. However, it should be better to improve their iron status after starting menarche by increasing iron intake, especially heme-iron, and enhancing factors for iron absorption.

• The Korean Journal of Quaternary Research
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• v.18 no.2 s.23
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• pp.3-3
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• 2004

One short core with length of 146cm(HB-107, at coordinates of $N51^{\circ}$11'37.5";$E100^{\circ}$24'45.6", from 229m water depth was subject of the present study. The sub-samples of the core were analyzed for the water contents (WC%), biogenic silica, identification of the main phases, grain size distribution, geochemistry and some physical properties of sediment(Wet density and Magnetic susceptibility) with aims of recording palaeo-environmental changes in Northem Mongolia. The evaluation of the geochemical and mineralogical proxies on palaeo-climated and palaeo-environmental changes are based on comparison to the behvior of biogenic silica through core, as later one had been showed itself, as good indicator of the climate and environmental fluctuation. Age model of the investigating core based on previously C 14 dated core HB105 taken from the central part of the Hobsgol Lake and the result had been published elsewhere. The core consists of two litological varieties : upper diatomaceous silt, lower clay. According to the age model the upper diatomaceous silt formed during the Holocene, lower caly-during the late Pleistocene glacial period. The geochemistry and phase identification analysis on the core samples are resulted in determining main minerals that form the bottom sediments and their geochemistry. The main include quartz, felspar, muscovite, clinochlore, amphibole and carbonate phase(dolomite and calcite). Through the core not only occur the relative quantitative changes of the main phases, but also happen that the carbonate phase completely disappear in diatomaceous silt. This is believed to be related to the lake water salinity changes, which occurred during the trassition period from Pleistocene glacial-to the Holocene interglacial. These abrupt changes of the mineralogy have been clearly traced in geochemistry of sediments, specially in calcium concentration, which is high in lower clay and low in upper diatomaceous silt. That means, geochemistry and mineralogy of the bottom sediments can be used as proxy data on palaeo-climate and palaeo-environmental changes.

• Magazine of the Korea Concrete Institute
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• v.11 no.2
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• pp.95-103
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• 1999

The reduction phenomena of concrete compressive strength with the size of specimens have been extensively investigated, but till now the adequate analysis technique is not fixed. The existing research results show that the bigger the member size, the smaller the strength. This means the nonlinear fracture mechanics theory is needed in order to analyze the fracture behaviors of concrete and the size effect. There is a few model equations that is to predict the size effect of compressive strength of standard and non-standard cylindrical specimen. However, theses equations did not considered the difference of fracturing mechanism which depends on the strength level. In this paper, model equations to predict compressive strength of concrete considering the size effect and strength level are suggested. The size effect model suggested in this paper shows good prediction compared with the existing test data of various concrete size and strength level.