• The Journal of the Petrological Society of Korea
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• v.8 no.1
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• pp.24-33
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• 1999

Differential Strain Analysis (DSA) was performed to examine the characteristics of microcracks for the granites from two sites, Noeunri and Gunggiri. The results of the DSA are taken every 5 MPa for the first 50 MPa, then every 10 MPa to a pressure of 100 MPa, and then every 15 MPa to a pressure of 250 MPa. Differential strain was measured on core samples in three horizontal directions, using $45^{\circ}$ rosette strain gages, and one vertical direction. The gradients of cumulative crack strain curves in one vertical direction and three horizontal directions differed from one another, indicating anisotropic crack development in the sample. The magnitude of vertical cumulative crack strain was the highest, indicating that the microcracks from the studied rock are generally developed in horizontal direction. Under the pressure of 240 Mpa, vertical cumulative crack strains for samples N-1, N-2, G-1, and G-2 were $74{\times}l0^{-6}~820{\times}l0^{-6},\; 190{\times}l0^{-6}~460{\times}l0^{-6},\; 329{\times}l0^{-6}~836{\times}l0^{-6},\; 833{\times}10^{-6}~1,592{\times}l0^{-6}$, respectively. Under the pressure of 25O MPa, volumetric crack strains for Gunggiri and Noeunri ranged from $1,804{\times}10^{-6}\; to\; 3,936{\times}10^{-6}\; and \;from,\; 1, 125{\times}10^{-6}\; to\; 1,457{\times}10^{-6}$, respectively. Therefore, the amount of microcrackes produced were more distributed in Gunggiri than Noeunri. The ratio of a maximum crack strain to a minimum crack strain was calculated to find the orientations between microcracks and the rift plane of the granites. Generally, the ratio has very high values ranging from 2.42 to 3.43, which suggests most microcracks to be intragranular cracks with the regular orientations. These results indicate that the preferred orientations of microcracks in the granites were almost parallel to the rift plane of the granites.

• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.4
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• pp.83-97
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• 2011

In this study, space allocation with an assessment system for improving the function of the ecological use and function of each space was undertaken to suggest appropriate goals and directions. Ogeum Park, used as the study site, is a stronghold green zone located in the fan-shaped area of the Songpa-gu green zone on a 22ha area site. The assessment system for this study consisted of a total of 3 steps: Step 1 includes the division of the spatial block, Step 2 assesses the proper functioning of each spatial block, while Step 3 includes space allocation and presents improvements for function by space. This study performed a basin analysis with the consideration that Ogeum Park is a forest area and divided the site into a total of 8 areas according to how the sections of land are used. The function of wildlife habitat included an analysis of plant ecology(vegetation type, vegetation layer, potential vegetation), animal ecology(wild birds), and waterways. The function of leisure and use included an analysis of gradients, noise, paths, status of use, and status of facilities. The evaluation of the function of habitat sorted items into native vegetation, vegetation diversification, vegetation potential, animal diversification and potential of animal habitats. The results of grading the evaluation scores by space in the function of habitat showed that the Areas IV and VII, which were 90% of the maximum point, were Grade A, Areas II and V were Grade B at 70% and Area I and VI were Grade C at 50%. Areas III and VIII, which were not found to be beyond the standard of 50%, were excluded. The evaluation of the functions of leisure and use classified items into use potential, use preference, use concentration, use diversification and use convenience. The results of the graded evaluation scores by space in use function, showed areas V and VI as Grade A, or 90% of the maximum score. Grade B, 70% of the maximum score, was given to Areas I and VII. Grade C, 50% of the maximum score, included Areas II, IV and VIII. Area III, graded lower the standard of 50%, was excluded. The study evaluated areas according to a common standard, classified spaces by proper functions into ecological spaces, environmentally-friendly use spaces and use spaces according to the standard of spatial distribution on the basis of the above results through a synthesis of grades of habitat function, leisure function and use. This offers ideas for the improvement of wildlife habitat and environment-friendly use functions by space.

• Journal of Bio-Environment Control
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• v.27 no.1
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• pp.34-39
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• 2018

This research was conducted to estimate moisture content in cucurbitaceae seedlings, such as cucumber and watermelon, using hyperspectral imagery. Using a hyperspectral image acquisition system, the reflectance of leaf area of cucumber and watermelon seedlings was calculated after providing water stress. Then, moisture content in each seedling was measured by using a dry oven. Finally, using reflectance and moisture content, the moisture content estimation models were developed by PLSR analysis. After developing the estimation models, performance of the cucumber showed 0.73 of $R^2$, 1.45% of RMSE, and 1.58% of RE. Performance of the watermelon showed 0.66 of $R^2$, 1.06% of RMSE, and 1.14% of RE. The model performed slightly better after removing one sample from cucumber seedlings as outlier and unnecessary. Hence, the performance of new model for cucumber seedlings showed 0.79 of $R^2$, 1.10% of RMSE, and 1.20% of RE. The model performance combined with all samples showed 0.67 of $R^2$, 1.26% of RMSE, and 1.36% of RE. The model of cucumber showed better performance than the model of watermelon. This is because variables of cucumber are consisted of widely distributed variation, and it affected the performance. Further, accuracy and precision of the cucumber model were increased when an insignificant sample was eliminated from the dataset. Finally, it is considered that both models can be significantly used to estimate moisture content, as gradients of trend line are almost same and intersected. It is considered that the accuracy and precision of the estimating models possibly can be improved, if the models are constructed by using variables with widely distributed variation. The improved models will be utilized as the basis for developing low-priced sensors.

• Investigative Magnetic Resonance Imaging
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• v.8 no.1
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• pp.42-49
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• 2004

Purpose : The quantization noise in magnetic resonance imaging (MRI) systems is analyzed. The signal-to-quantization noise ratio (SQNR) in the reconstructed image is derived from the level of quantization in the signal in spatial frequency domain. Based on the derived formula, the SQNRs in various main magnetic fields with different receiver systems are evaluated. From the evaluation, the quantization noise could be a major noise source determining overall system signal-to-noise ratio (SNR) in high field MRI system. A few methods to reduce the quantization noise are suggested. Materials and methods : In Fourier imaging methods, spin density distribution is encoded by phase and frequency encoding gradients in such a way that it becomes a distribution in the spatial frequency domain. Thus the quantization noise in the spatial frequency domain is expressed in terms of the SQNR in the reconstructed image. The validity of the derived formula is confirmed by experiments and computer simulation. Results : Using the derived formula, the SQNRs in various main magnetic fields with various receiver systems are evaluated. Since the quantization noise is proportional to the signal amplitude, yet it cannot be reduced by simple signal averaging, it could be a serious problem in high field imaging. In many receiver systems employing analog-to-digital converters (ADC) of 16 bits/sample, the quantization noise could be a major noise source limiting overall system SNR, especially in a high field imaging. Conclusion : The field strength of MRI system keeps going higher for functional imaging and spectroscopy. In high field MRI system, signal amplitude becomes larger with more susceptibility effect and wider spectral separation. Since the quantization noise is proportional to the signal amplitude, if the conversion bits of the ADCs in the receiver system are not large enough, the increase of signal amplitude may not be fully utilized for the SNR enhancement due to the increase of the quantization noise. Evaluation of the SQNR for various systems using the formula shows that the quantization noise could be a major noise source limiting overall system SNR, especially in three dimensional imaging in a high field imaging. Oversampling and off-center sampling would be an alternative solution to reduce the quantization noise without replacement of the receiver system.

• The Journal of the Korean life insurance medical association
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• v.2 no.1
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• pp.195-217
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• 1985

A statistical analysis on the ratio of weight-for-height in insurance medicine was carried out in a total of 12,690 insured persons who were medically examined at the Honam medical department, Dong Bang life insurance company, ltd. from June, 1979 to February, 1984. The results were as follows: 1. The mean value of the ratio of weight-for-height(W/H ratio) was $102.3{\pm}11.3%$ in all males, and $105.2{\pm}103.6%$ in all females. The difference of the values between males and females showed statistical significance(P<0.001). The mean value of W/H ratio in all the insureds was $103.8{\pm}12.9%$. In each age group, the mean value of female was higher than that of male without exception(P<0.001). The mean value of both sexes in each age group showed gradual increase with age except for the age group over 50(P<0.001). 2. The incidences of the average weighted, overweighted and underweighted lives were respectively 91.6% in all males, 84.2% in all females(P<0.001); 7.9% in all males, 15.4% in all females(P<0.001); 0.5% in all males, 0.4% in all females(P>0.05). The incidences of average weighted, overweighted and underweighted lives in all the insureds were respectively 87.6%, 12.0% and 0.5%. The incidence of the average weighted lives in male in each age group was always higher than that in female with the exception of the age group below 19(P<0.001), whereas the incidence of the overweighted lives in male in each age group was always lower than that in female(P<0.05 in the age group below 19, P<0.001 in the other age groups). The incidence of average weighted lives of both sexes in each age group showed gradual decrease with age from the second to fifth decade(P<0.001), whereas the incidence of the overweighted lives of both sexes in each age group showed gradual increase with age from the second to fifth decade(P<0.001). 3. The relative frequency distribution polygons of W/H ratio of both sexes drawn in a pair on one coordinate plane revealed lying in juxtaposition each other horizontally and showed the shifting of female's polygon to male's one toward the direction of greater value of W/H ratio at a short distance which increased gradually with age. 4. Correlations between both sexes and among age groups relating to W/H ratios of the insureds seem to be a physiological phenomenon of body build and should be considered on the rating of the build. Author prepared a rating table of build based on the correlations above menthioned. Some gradients by sex and age in the rating table of build are organized; in female group, the ratings of 0, 30-50, 50-100 and 100-D are to calculate by the build with W/H ratio of 80-125%, $126{\sim}145%,\;146{\sim}165%$ and over 166% respectively in the age group of 29 or under, by the build with W/H ratio of $80{\sim}130%,\;131{\sim}150%,\;151{\sim}170%$ and over 171% respectively in the age group of $30{\sim}59$, and by the build with W/H ratio of $80{\sim}135%,\;136{\sim}155%,\;156{\sim}175%$ and over 176% respectively in the age group of 60 or over. In male group, the ratings of 0, $30{\sim}50$, 50-100, and 100-D are to calculate by the build with W/H ratio of $80{\sim}120%,\;121{\sim}140%,\;141{\sim}160%$ and over 161% respectively in all ages. Of under weighted lives, in both sexes, the ratings of 30-50 and 50-D are to calculate by the build with W/H ratio of $76{\sim}79%$ and under 75% respectively. The results of the ratings according to a rating table by author were as follows: The incidence of the ratings of 0, 30-50, 50-100 and 100-D showed no difference between male and female. The incidence of the ratings of 0(indicating the average weighted lives) showed gradual decrease with age and the incidence of the ratings of 30-50 and 50-100(indicating the overweighted lives) showed gradual increase with age. These results are thought to be considerably reasonable because the incidence of the builds in each age group is supposed to have no difference by sex and the incidence of the overweighted lives would increase with age.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.4
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• pp.362-371
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• 2016

The distribution patterns of Chromophoric Dissolved Organic Matter (CDOM) and the chemical characteristics of CDOM in the Seomjin river estuary were investigated in March, June and July 2012 in order to determine the spatial and temporal variability of CDOM along the salinity gradient considering the effects of mixing, nutrients and Chl a. The average CDOM values were $1.0{\pm}0.3m^{-1}$, $1.3{\pm}0.4m^{-1}$, and $1.4{\pm}0.3m^{-1}$ in March, June and July, respectively. A high concentration of CDOM (greater than $1.5m^{-1}$) was found at the head of the river which decreased towards the river mouth to as low as less than $0.5m^{-1}$. The average concentrations of CDOM increased from the dry season (March and June) to the wet season (July), and the average slope values ($S_{300-500}$), which were used as indicators of CDOM characteristics and sources, were in the range of $0.013-0.018m^{-1}$. The CDOM and $S_{300-50}$ values showed that not only the concentration of CDOM but also the chemical properties of DOM clearly changed between upstream and downstream in the Seomjin river. CDOM and FDOM showed a negative correlation with salinity ($R^2$ > 0.8), and CDOM was positively correlated with FDOM. Furthermore, the mixing pattern of CDOM was confirmed as conservative for all seasons. The main environmental factors influencing the concentration of CDOM was confirmed as conservative for all seasons. The main environmental factors influencing the concentration of CDOM were salinity (mixing) and water temperature, which meant the dilution of low CDOM seawater, was the controlling factor for the spatial distribution of CDOM. Increases in water temperature seemed to induce the production of CDOM during summer (June and July) through the biological degradation of DOM either by microbial activity or photo-degradation.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.2
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• pp.196-205
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• 2008

Variability in vertical ozone and meteorological profiles was measured by 2Z electrochemical concentration cells (ECC) ozonesonde at Bangyi in Seoul ($37.52^{\circ}N$, $127.13^{\circ}E$) during June $6{\sim}9$, 2003 in odor to identify the vertical distribution of ozone and its relationship with the lower-atmospheric structure resulted in the high ozone concentrations near the surface. The eight profiles obtained in the early morning and the late afternoon during the study period clearly showed that the substantial change of ozone concentrations in lower atmosphere(${\sim}5\;km$), indicating that it is tightly coupled to the variation of the planetary boundary layer (PBL) structure as well as the background synoptic flow. All profiles observed early in the morning showed very low ozone concentrations near the surface with strong vertical gradients in the nocturnal stable boundary layer due to the photochemical ozone loss caused by surface NO titration under very weak vertical mixing. On the other hand, relatively uniform ozone profiles in the developed mixing layer and the ozone peaks in the upper PBL, were observed in the late afternoon. It was noted that a significant increase in ozone concentrations in the lower atmosphere occurred with the corresponding decrease of the mixing height in the late afternoon on June 8. Ozone in upper layer did not vertically vary much compared to that in PBL but changed significantly on June 6 that was closely associated with the variation of synoptic flows. Interestingly, heavily polluted ozone layers aloft (a maximum value of 115 ppb around 2 km) were formed early in the morning on 6 through 7 June under dominant westerly synoptic flows. This indicates the effects of the transport of pollutants on regional scale and consequently can give a rise to increase the surface ozone concentration by downward mixing processes enhanced in the afternoon.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.12
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• pp.828-836
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• 2014

The purpose of this study evaluates the water quality of artificial deep pool (ADP) during the late spring and summer. we monitored the water quality, as pH, dissolved oxygen (DO), temperature and conductivity at two stations (St. 1. open water, St. 2. in the ADP). The water quality in the ADP is very stable, and temperature and DO are lower than the open water (average value; temperature $1.4{\sim}3.2^{\circ}C$, DO 2.4~3.6 mg/L). In particular, daily variation of temperature in the open water showed above $4^{\circ}C$, but ADP remained stable. The water quality was analyzed using two-way analysis of variance (ANOVA). The results of the analysis showed difference about temperature, pH, DO, conductivity (two-way ANOVA, p<0.05). The ADP has created an aqua environment in thermal and DO gradients by depth. About 1.2 m, Temperature and DO were sharply decreased. The Rhodeus uyekii is dominant species in pond of this study. The ADP offers optimum water temperature ($16.5{\sim}18.5^{\circ}C$) to the Rhodeus uyekii about spawning. Consequently, the ADP offers stable habitat than open water for fish and aquatic organisms during the summer. It is also a good shelter for fish from a thermal stress.

• Radiation Oncology Journal
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• v.14 no.2
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• pp.149-158
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• 1996

Purpose : To get an accute steepness of dose gradients at outside the target volume in intracranial lesion and a less limitation of beam selection avoiding the high dose at normal brain tissue, this Photon Knife Radiosurgery System was developed in order to provide the three-dimensional dose distribution through the reconstruction of CT scan and the combined stereotactic trans-multiarc beam mode based on linear accelerator photon beam. Materials and methods : This stereotactic radiosurgery, Photon Knife based on linear accelerator photon beam was provided the non-coplanar multiarc and trans-multiarc irradiations. The stereotactic trans-multiarc beam mode can be obtained from the patient position in decubitus. This study has provided the 3-dimensional isodose curve and anatomical structures with the surface rendering technique. The dose distribution from the combined two trans-multiarcs (2M 2TM) was compared to that of four non-coplanar multiarcs (4M) with same collimator size of 25 mm in a diameter and total gantry movements. Results : In this study, it shows that the dose distributions of stereotactic beam mode are significantly depended on the selected couch and gantry angle in same collimator size. Practical dose distribution of combined stereotactic trans-multiarc beam has shown a more small rim thickness than that of the non-coplanar multiarc beam mode in axial, sagittal and coronal plane in our study. 3-Dimensional dose line displayed with surface rendering of irregular target shape is helpful to determine the target dose and to predict the prognosis in follow-up radiosurgery. Conclusions : 3-Dimensional dose line displayed with surface rendering of irregular target shape is essential in stereotactic radiosurgery. This combined stereotactic trans-multiarc beam has shown a less limitation of the selection couch and gantry beam angles for the target surrounding critical organs. It has shown that the dose distribution of combined trans-multiarc beam greatly depended on the couch and gantry angles. In our experiments, the absorbed dose has been decreased to $27%$ / mm in maximum at the interval of $50\%$ to $80\%$ of isodose line.

• Journal of Korean Society of Forest Science
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• v.84 no.2
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• pp.266-274
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• 1995

Vegetational data from 62 quadrats of Pinus densiflora for. erecta and Chunyang-type of Pines densiflora forests were analyzed by using two multivariate methods : TWo-way INdicator Species ANalysis(TWINSPAN) for classification and Detrended Canonical Correspondence Analysis(DCCA) for ordination. The dominant tree species of Pinus densiflora for. erecta communities were found in the order of Pines densiflora for. erecta, Quercus mongolica, Quercus variabilis, Lindera obtusiloba, Fraxinus rhynchophylla, and Rhus trichocapa. The dominant tree species of Chunyang -type of Pinus densiflora communities were Quercue variabilis. Quercue mongolica, Fraxiraus sieboldiana, Styrax obassia, and Quercus serrata. The forest vegetation of Pinus densiflora was classified into Quercars variabilis-Styrax obassia. Quercus variabilis Quercus variabilis-Quercus mongolica, and Quercue mongolica communities according to TWINSPAN. Pinus densiflora for. erecta community was distributed in the good nutrition area of total nitrogen. organic matter, $K^+$, $Ca^{{+}+}$, $Mg^{{+}+}$, and canon exchange capacity, while Chunyang type of Pinus densiflora community in the good nutrition area of $P_2O_5$. The relationship between the distribution of dominant communities for forest vegetation and soil condition in Pinus densiflora communities was investigated by analysing the elevation and soil nutrition gradients. Quercus mongolica community was distributed in the high elevation and good nutrition area of total nitrogen, organic matter, and ration exchange capacity, while Quercus variabilis community was distributed in the low elevation and poor nutrition area of total nitrogen, organic matter, and ration exchange capacity. Quercus variabilis Styrax obassia and Quercus variabilis-Quercus mongolica community was distributed en the medium elevation and medium nutrition area.