• Journal of the Korean Geophysical Society
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• v.5 no.4
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• pp.293-303
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• 2002

Applying elastic plate model, we estimated elastic thickness and rigidity of the lithosphere in southern part of the Korean Peninsula($332km{\times}332km$ area of which center is $36.5^{\circ}N$ in latitude and $127.5^{\circ}E$ in longitude) by analysing terrain data and gravity data measured up to 2002. We tried to exclude the East Sea in choosing the study area because it has different tectonic environment. The mean Moho depth was estimated to be 30 km by power spectrum analysis of gravity data in the study area, Assuming one layer crust and applying elastic plate model, the loads with wavelengths of greater than 300 km are locally compensated, loads with wavelengths in the range 80-300km are partially supported by the strength of the lithosphere, and loads with wavelengths of less than 80km are almost completely supported by lithospheric strength. Assuming crustal model and rigidity, we calculated predicted coherence and compared it with observed coherence. As a result, we wert able to estimate the effective elastic thickness to be of 15 km(corresponding flexural rigidity is $3.0{\times}10^{22}Nm$). This indicates that the crust of the study area is relatively weaker than other old and stable continental regions but is similar to continental margins or oceanic area. The low rigidity could be explained by many tectonic and thermal activities such as orogenic activities, magmatic intrusions, volcanic activities, foldings, faultings, etc.

• The Journal of Korean Medicine
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• v.23 no.1
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• pp.120-132
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• 2002

Objectives : The purpose of this investigation was to evaluate the effect of Goomicheongsim-won Extracts on E20 corticells and P7 cerebellar cells exposed to hypoxia, and the effect on neuronal protection by elimination of Rhinoceros unicornis L. and/or Orpiment $As_2S_3$. Methods : P7 cerebellar cells were grown in various concentrations of KM-A, KM-B, KM- C and KM-D. On 7 DIV (day in vitro), cells were exposed to hypoxia (98% $N_2/5%{;}CO_2,{\;}3{\;}hr,{\;}37^{\circ}C$) and normoxia, and then further incubated for 3 days. Neuronal viabilities were expressed as percentages of control. E20 cortical cells were grown in various concentrations of KM-A, KM-B, KM-C, and KM-D. On 7 DIV, cells were exposed to hypoxia and normoxia, and then further incubated for 3 and 7 days. Results : I. The effect of KM-A on neuronal protection was significantly increased P7 cerebellar granule cells and E20 cortical cells on normoxia and hypoxia. 2. The effect of KM-B on neuronal protection was increased P7 cerebellar granule cells on normoxia, but was significantly decreased P7 cerebellar granule cells on hypoxia. The effect of KM-B on neuronal protection was non-significantly increased E20 cortical cells on normoxia and hypoxia. 3. The effect of KM-C on neuronal protection was non-significantly increased P7 cerebellar granule cells on normoxia and hypoxia and was decreased (p=0.058) on hyperconcentration of the extracts in normoxia. The effect of KM-C on neuronal protection was significantly increased P7 cerebellar granule cells and E20 cortical cells on normoxia and hypoxia (10 DIV), and the effect was E20 cortical cells on normoxia (14 DIV), non-significantly increased E20 cortical cells on hypoxia (14DIV). 4. The effect of KM-D on neuronal protection was increased P7 cerebellar granule cells on normoxia but was not on hyperconcentration of the extracts, was significantly decreased on hyperconcentration of the extracts in hypoxia. The effect of KM-D on neuronal protection was significantly increased E20 cortical cells on normoxia and was significantly increased E20 cortical cells increased on hypoxia (10 DIV). Conclusions : Goomicheongsim-won extracts had applicable effect on E20 corticells and P7 cerebellar cells exposed to hypoxia. The effect on neuronal protection by elimination of Rhinoceros unicornis L. and/or Orpiment $As_2S_3$ was changed.

• Korean Journal of Environment and Ecology
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• v.30 no.2
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• pp.146-154
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• 2016

In this study, understanding the habitats on spot-billed duck that wintering-breed in the korea, which using the GPS-Mobile based Telemtry (WT-200), I tried to take advantage as the basic data of the protection and management of the habitats of the waterbirds of Korea. Study area is Gyeonggi-do Bokhacheon, Chonmichon, Chungcheongnam-do Gokugyochon, Chungcheongbuk-do Byeongcheoncheon, Jeollabuk-do Mangyunggang, which Five rivers and Jeju Island reservoir, I have attached the tracking of the location(WT -200) to the twenty-five spot-billed ducks. among twenty five ducks, twelve ducks moved to overseas countries, the arrival site was China, North Korea, Russia. Moving average distance was 683km, the largest distance was 1,238km. The average northbound starting date was April 26. The average daily movement distance of thirteen ducks remaining in the domestic country is $1.0{\pm}0.89km$, maximum travel distance was 23.8km. The average daily movement distance of wintering prior to average going north dating is a 0.9km, is the largest 14.6km, the breeding season is an average 1.3km, maximum was 14.4km. Spot-billed duck used the rivers in domestic country most frequently, following was rice field, a filed, reservoir. It used the river most frequently during the wintering period, in the breeding season it used paddy paddies most frequently. While wintering, during the day and night's utilization rate was the highest in the river, but utilization rate was incleased on filed, paddy filed at night. During breeding season, daytime and night's utilization rate was the highest but, utilization rate was increased on river and utilization rate was decreased on river. In accordance with time change, spot-billed duck showed different tendency in paddy fields, and they utilized the filed adjacent to rivers mostly.

• Korean Journal of Optics and Photonics
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• v.8 no.4
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• pp.327-332
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• 1997

We fabricated the high speed 1.55${\mu}{\textrm}{m}$ distributed feedback laser diodes (DFB-LD) using both two-step mesa etching process and semi-insulating InP current blocking layers. The devices characteristics were threshold current of ~15mA, slope efficiency of ~0.13mW/mA, and dynamic resistance of ~6.0Ω, with as-cleaved facets. The fabricated DFB-LD showed the single longitudinal mode with more than 40dB up to 6 $I_{th}$(CW condition), emitting at the wavelength of 0.546${\mu}{\textrm}{m}$. The -3dB bandwidth was >10㎓ at the driving current of 27mA, and the maximum -3dB bandwidth was ~18㎓ at 90 mA current, showing the superior frequency response of SI-PBH DFB-LD. In the 10Gb/s transmission experiment for 1.55${\mu}{\textrm}{m}$ DFB-LD module, maximum 10 km of single mode fiber(SMF) or 80 km of dispersion shifted fiber (DSF) could be transmitted with error free.

• Bulletin of the Korean Space Science Society
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• 2011.04a
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• pp.24.4-24.4
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• 2011

Frozen orbit concept is very useful in designing particular mission orbits including the Sun-synchronous and minimum altitude variation orbits. In this work, variety of frozen and Sun-synchronous orbit conditions around the Moon is investigated and analyzed. The first two zonal harmonics of the Moon, J2 and J3, are considered to determine mean orbital elements to be a frozen orbit. To check the long-term behavior of a frozen orbit, formerly developed YonSei Precise Lunar Orbit Propagator (YSPLOP) is used. First, frozen orbit solutions without conditions to be the Sun-synchronous orbit is investigated. Various mean semi-major axes having between ranges from 1,788 km to 1,938 km with inclinations from 30 deg to 150 deg are considered. It is found that a polar orbit (90 deg of inclination) having 100 km of altitude requires the orbital eccentricity of about 0.01975 for a frozen orbit. Also, mean apolune and perilune altitudes for this case is about 136.301 km and 63.694 km, respectively. Second, frozen orbit solutions with additional condition to be the Sun-synchronous orbit is investigated. It is discovered that orbital inclinations are increased from 138.223 deg to 171.553 deg when mean altitude ranged from 50 km to 200 km. For the most usual mission altitude at the Moon (100 km), the Sun-synchronous orbit condition is satisfied with the eccentricity of 0.01124 and 145.235 deg of inclination. For this case, mean apolune and perilune altitudes are found to be about 120.677 km and 79.323 km, respectively. The results analyzed in this work could be useful to design a preliminary mapping orbit as well as to estimate basic on-board payloads' system requirements, for a future Korea's lunar orbiter mission. Other detailed perturbative effects should be considered in the further study, to analyze more accurate frozen orbit conditions at the Moon.

• Journal of Korean Society on Water Environment
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• v.25 no.5
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• pp.689-696
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• 2009

Unit load approach has been used to estimate the non-point pollutant load in Total Water Pollution Load Management System (TWPLMS). In this study, locally applicable unit loads for road and parking lot were developed based on the measurements of 9 rainfall events from 2007 to 2008 in Yongin city of Gyeongan stream watershed. Observations showed that stormwater runoff began at low precipitation (>1 mm) and peak pollutant concentration occurred at the beginning of the runoff because of impervious nature of the sites. Averaged event mean concentrations (EMCs) of road (parking lot) were estimated as COD 105.36(62.69) mg/L, BOD 15.94(13.20) mg/L, TSS 183.45(66.52) mg/L, T-N 4.63(3.28) mg/L, T-P 0.45(0.39) mg/L. Higher EMCs at the road than parking lot may reflect heavier traffic. Unit loads Estimated from the EMCs and 10 year average rainfall data were COD $331.17kg/km^2{\cdot}day$, BOD $50.20kg/km^2{\cdot}day$, TSS $580.13kg/km^2{\cdot}day$, T-N $14.68kg/km^2{\cdot}day$, T-P $1.43kg/km^2{\cdot}day$ in the road and COD $186.59kg/km^2{\cdot}day$, BOD $39.22kg/km^2{\cdot}day$, TSS $199.15kg/km^2{\cdot}day$, T-N $9.70kg/km^2{\cdot}day$, T-P $1.16kg/km^2{\cdot}day$ in the parking lot. The estimated unit loads are not so comparable to the ones listed in TWPLMS technical guideline and published data that locally developed unit loads should be used to estimate non-point pollutant loads.

• Applied Biological Chemistry
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• v.39 no.3
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• pp.165-171
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• 1996

The rheological properties of biopolymers produced by Bacillus sp. K-1 and its mutant strains(KM-21, KM-83) were studied. Apparent viscosity of biopolymers decreased as rising the temperature. The biopolymer produced by KM-21 strain showed 1.7 times low viscosity, 2.7 times low viscosity by K-1 and 1.9 times low viscosity by KM-83 at $80^{\circ}C$ compared with at $20^{\circ}C$ respectively. The viscosity of biopolymer solution also increased with increasing the polymer concentration and showed pseudoplastic characteristics which is high temperature dependency in all concentration. The change of the biopolymer viscosity on the pH showed the highest value at the pH 7.0 and it showed lower at acidic condition than at alkaline condition comparatively.

• Journal of the Korea Organic Resources Recycling Association
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• v.17 no.1
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• pp.103-109
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• 2009

Analysis of collection factor was studied to compare various parameters such as collection time, transport time, amount of collection and number of man power by on-the-spot survey at one municipal area and one rural area in Jeju-do. Results showed that the amount of man and time to collect 1 ton of waste of rural area($5.853man{\cdot}hour\;per\;time$) was four times as much as that of municipal area($1.527man{\cdot}hour\;per\;time$). In case of a transport time, rural area(11.08 per km/hr) has similar value to municipal area(11.07 per km/hr) and has half or one third value to the restaurant(36.7km/hr), an apartment area(33.0km/hr) and a detached area(22.4km/hr).

• Journal of Korea Water Resources Association
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• v.38 no.6 s.155
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• pp.495-504
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• 2005

The objective of this study is to estimate the impacts of land cover change on the runoff behavior using Hydrologic Simulation Program-Fortran (HSPF) model and Landsat images. Land cover maps were prepared using three every ten years from 1980 to 2000 of the upper watershed ($258\;km^2$) of Gyeongan stream. Hydrologic parameters of HSPF were calibrated using observed data (1999 - 2000) and validated using observed data (2001, 2003) at Gyeongan gauge station. The simulation results showed that runoff volume and peak rate increased as $15.0\;km^2$ forest areas decreased and $19.3\;km^2$ urban areas increased for 20 years land use changes. The runoff volume showed a higher rate of increase in wet year (2003, 1709.4 mm) than in dry year (2001, 871.2 mm). The peak runoff increased $13.3\;\%$ in normal year (2000, 1257.3 mm) because the year has the highest rain intensity (241.3 mm/hr) among the test years. The runoff volume of a dry season and a wet season (May - September) in normal year 2000 increased $4.4\;\%$ and decreased $8.1\;\%$, respectively.

• Journal of Society of Preventive Korean Medicine
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• v.20 no.1
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• pp.89-97
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• 2016

Objectives : The purpose of this study was to investigate the real status of the utilization of Korean medicine (KM) treatment among children with cerebral palsy (CP). Methods : In a prospective observational multicenter study for children with CP aged from 6 months to 78 months, we analyzed 69 questionnaires of children currently receiving or have received KM treatment such as acupuncture and Korean herbal medicine for CP. Results : Of all the 170 participants, 32 children was currently getting KM treatment and they were getting acupuncture therapy 2.5 times per week on average. The mean expenditure per month for acupuncture and herbal medicine was respectively 32,000won and 501,000won. 37 children have discontinued KM treatment. The most frequent reason for quitting acupuncture therapy was 'inconvenience' (40.7%), followed by 'suffering of children' (33.3%). The average duration of taking Korean herbal medicine was 3.78 months and the highest reason of stopping medicine was 'rejection of children' (32.3%), followed by the 'cost burden' (22.6%). 75% of currently KM using group answered they have experienced positive effect of KM and the rate was 48.6% among the group who have ceased KM. There was a significant difference between the two groups(p=0.025). Conclusions : Further study will be required to increase the therapeutic effect and utilization of KM among the children with CP. More efforts should be made to develop less invasive acupuncture method and various shape of KM herbal medicine and to expand the insurance coverage of KM for children with CP.