• Economic and Environmental Geology
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• v.35 no.5
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• pp.445-454
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• 2002

3-D P-wave velocity model in the southern Korean Peninsula is investigated by using the earthquake tomography method. This velocity model would be used to locate the exact hypocenter position, and also useful for our understanding of the crustal structure. The simultaneous inversion is used to get the minimum 1-D model and hypo-center relocation, which are used as an initial 3-D velocity model. The velocities in the minimum 1-D model are 6.04 km/s, 6.45 km/s, and 7.78 km/s between the depth of 0-19 km, 19-32 km, and 32-55 km respectively. In the 3-D P-wave velocity model, Layer 1 (0~3 km) has high velocities in Kyongsang basin, Yonglam massif, and Okchon folded belt, and low velocities in Kyonggi massif. In layer 2 (3~19 km) high velocities are predominent around Kyonsang basin and Yongnam massif except Yonil basin, but low velocities exist around Kyonggi massif and Okchon folded belt. In Laye. 3 (19~32 km) high velocities prevail throughout the southern part of Korean Peninsula, but low velocity does throughout the middle except SNU, YIN station in Konggi massif. In Layer 4 (32 km), the maximum velocity is showed in the middle and southwestern part, while the minimum velocity in the southeastern and coastal area. The depth of the velocity boundary corresponds to the crustal structure of the southern Korean Peninsula which is calculated by gravity data.

• Economic and Environmental Geology
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• v.40 no.6
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• pp.751-759
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• 2007

To better understand the subsurface geological structure of the Kunsan Basin in the Yellow Sea, the mean depths of the density discontinuous layers (DDLs) of the Kunsan Basin were calculated by power spectrum analysis using satellite altimetry gravity data. The calculated mean depths of DDLs were -1.1km, -3.4km, -9.1km and -31.0km. The mean depth of -1.1km DDL was interpreted as regional unconformity shown in about 1 second in two way travel time (TWTT) in the seismic reflection profiles, and the mean depth of -3.4km DDL was also interpreted as top of the acoustic basement in the seismic reflection profiles. Comparing with well data, seismic reflection profiles and regional geology in the study area, the mean depth of -9.1km DDL was interpreted as top of the igneous origin basement. This means that the acoustic basement of the study area is composed mainly of sediments which are disregarded in previous study. The mean depth of -31.0km DDL was interpreted as the Moho discontinuity because this mean depth is similar to one of the normal continental crust thickness. The detection of top of the igneous origin basement suggests that oil gas potential analysis in Kunsan Basin needs to be extended to the deeper part of sediments (acoustic basement).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.1
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• pp.197-203
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• 2013

Optical power optimization of 10 Gbps 40 wavelength division multiplexing channels was analyzed at the 3000 km long-haul transmission distance when the link span distance was changed between 40 km and 140 km. The signal performance of the transmission was obtained as a Q value and it was compared when input power into SSMF and input power into DCF on the transmission link were changed. The optimized input power into SSMF increased linearly to link span distance with 1 dB/km. The optimized power into DCF increased linearly with 0.5 dB/km up to 100 km link span, but it had no variation at longer link span than 100 km.

• Journal of Society of Preventive Korean Medicine
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• v.21 no.1
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• pp.1-8
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• 2017

Objectives : The concurrent use of Korean Medicine (KM) and Western Medicine (WM) for the management of disease are increasing. In this study, the factors determining the choice of concurrent use of KM and WM was investigated based on national survey data for the public. Methods : Survey data from 1239 people with experience treating diseases with KM were utilized for this study. The national survey data were gathered using e-mail and face-to-face interviews between December 2007 and January 2008. Results : Among people who had been treated with KM, 819 (66%) used both KM and WM to the treat same disease. Multivariable analysis revealed that concurrent users of KM and WM were significantly associated with age 40-69 (OR=1.43, 95% CI=1.12-1.82), university education or higher (OR=1.34; 95% CI=1.05-1.71), enhanced health status (OR = 0.47, 95% CI=0.35-0.62) and unsatisfied with WM (OR = 1.71, 95% CI=1.02-2.87). The respondents that reported KM was more effective than WM among concurrent users of KM and WM were significantly associated with being an office worker (OR=1.78, 95% CI=1.25-2.53), age 40-69 (OR = 0.62, 95% CI=0.44-0.86), unsatisfied with WM (OR=2.61, 95% CI=1.51-4.50) and overall satisfied with KM (OR=8.38, 95% CI=5.65-12.44) Conclusions : This study showed that two-thirds of KM user were concurrent user of KM and WM, and some influential factors determined the choice of a concurrent use of KM and WM. Therefore, Korean Medicine Doctors should consider the possibility of concurrent use, need to know the information on the benefits and risks of concurrent use.

• Journal of Korean Society of Forest Science
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• v.112 no.3
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• pp.267-279
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• 2023

This research assessed the feasibility of using high-resolution aerial images and deep learning algorithms for estimating the land-use and land-cover areas at the Approach 3 level, as outlined by the Intergovernmental Panel on Climate Change. The results from different sampling densities of high-resolution (51 cm) aerial images were compared with the land-cover map, provided by the Ministry of Environment, and analyzed to estimate the accuracy of the land-use and land-cover areas. Transfer learning was applied to the VGG16 architecture for the deep learning model, and sampling densities of 4 × 4 km, 2 × 4 km, 2 × 2 km, 1 × 2 km, 1 × 1 km, 500 × 500 m, and 250 × 250 m were used for estimating and evaluating the areas. The overall accuracy and kappa coefficient of the deep learning model were 91.1% and 88.8%, respectively. The F-scores, except for the pasture category, were >90% for all categories, indicating superior accuracy of the model. Chi-square tests of the sampling densities showed no significant difference in the area ratios of the land-cover map provided by the Ministry of Environment among all sampling densities except for 4 × 4 km at a significance level of p = 0.1. As the sampling density increased, the standard error and relative efficiency decreased. The relative standard error decreased to ≤15% for all land-cover categories at 1 × 1 km sampling density. These results indicated that a sampling density more detailed than 1 x 1 km is appropriate for estimating land-cover area at the local level.

• Economic and Environmental Geology
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• v.35 no.2
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• pp.163-170
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• 2002

The purpose of this study is to analyze the relationship between geology and geothermal gradient in South Korea using GIS. For the analysis, 352 temperature logging wells were constructed to spatial database and the relationships beween geothermal gradient and geological time and lithology were analyzed using the overlay the wells layer and 1:1,000,000 scale geological map layer. The average of the geothermal aradient of South Korea is 29.34$^{\circ}C$/km. In the geologic sequence, Cenozoic strata has 39.7$0^{\circ}C$/km, Mesozoic strata has 30.63$^{\circ}C$/km , Paleozoic strata has 22.32$^{\circ}C$/km, Proterozoic strata 23.15$^{\circ}C$/km geothermal gradient value. In the lithological aspect, plutonic rocks 33.96$^{\circ}C$/km, sedimentary rocks have 24.78$^{\circ}C$/km and sedimentary and volcanic rocks have 26.85$^{\circ}C$/km geotermal gradient value. The result can be used to develop geothermal energy and hot spring as a reference.

• Economic and Environmental Geology
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• v.18 no.4
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• pp.321-329
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• 1985

The gravity measurement has been conducted at 113 stations with an interval of about 1km along the national road of about 120km running from Busangdong to Pohang through Waekwan, Daegu, Youngchun and Aankang. The subsurface geology and structure along the survey line is interpreted from Bouguer anomaly by applying Fourier method and Talwani method for two dimensional body. The mean depth of Moho discontinuity is 31.4km, and the depth decreases very slowly from inner continent toward east coast. The depth of Conrad discontinuity increases from 11km at the east coastal area to 17km at the inner continental area, and especially increases rapidly in the area between Waekwan to Busangdong. The depth of basement of Kyoungsang Basin inereases from near Waekwan toward Daegu upto about 4. 8km, and increases rapidly to reach the maximum depth of about 8.5km at 8km east of Daegu. But it starts to decrease from the place of 10km west of Youngchun, and is about 7.2km at Youngchun and about 6km at 6km east of Youngchun. The depth starts to increase smoothly beyond this point, and is 7km at 15km east of Youngchun. From this point, the depth starts to decrease again, and is about 3.8km at Ankang. The depth of basement of Pohang Basin is 500m at Pohang and about 650m at 5km west of Pohang. A massive granite body which is considered to be a part of Palgongsan Granite exposed at the depth of 1. 5km at 9km west of Youngchun. Another massive granite body is situated underneath the Pohang Basin at depth of 1.5 to 2km, and sedimentary rocks of Kyoungsang Group and volcanic rocks are distributed between Pohang Basin and this granite body. Finally, Yangsan Fault is identified at about 2.5km east of Ankang.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.1A
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• pp.25-33
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• 2003

We derive the outage probabilities for the Erlang capacity and link margin based on handoffs in the reverse link of a CDMA system of 14.4 kbps/1.9 GHz band, calculate them with the same parameters, and then with the maximum realizable Erlang capacity analyze newly the cell coverage in different areas by the COST-231 model If it decreases from 5 % to 2 % in case of $E_b/N_0$=5 dB under a soft handoff, the result shows a very reliable link with additional increment of 0.88 dB in the margin and a high quality of service within the coverage decrease of 0.12 km, 0.25 km, and 1 km in a city, suburban, and open areas respectively on the decrease of 2 Erlang in the capacity. When the $E_b/N_0$ decreases from 7 dB to 5 dB within the outage probability of 5 %, it shows the increase of 9 Erlang and of 0.2 km in a city on the same margin of 2.8 dB. Then, comparing it with a single cell, it shows the decrease of more than 10 Erlang in the capacity, but the enlargement of 0.17 km, 0.3 km, and 1 km in them on the margin decrease of 1.31 dB, also, with a hard handoff, the soft handoff gain of the increase of 10 Erlang and of 0.22 km, 0.5 km, and 2 km on the decrease of 2.16 dB.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.14 no.2
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• pp.60-67
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• 2008

Purpose : The purpose of this study is to investigate that the change of lower-limb muscle activity when normal gait and assistive gait of older. Methods : The selected subjects of this study were 11 older who be in good physical health and have not problem to gait and over 60 age to analyze the muscle activity. This study has been conducted to analyze the muscle activity of normal gait and assistive gait in unitary status without any contrast group. We have them gait condition of a gradient of 0% and velocity of 1km/h, 2km/h, 3km/h electrode were attached to the motor point of Rectus femoris, Hamstrings, Tibialis anterior, Calf muscle. When normal gait and assistive gait performs, there are meaningful differences that the muscle activity takes a small drop in Rectus femoris by 9.17% at 1km/h, 9.79% at 2km/h, 13.80% at 3km/h, hamstring by 14.78% at 1km/h, 17.82% at 2km/h, 17.26% at 3km/h, Tibialis anterior by 24.38% at 1km/h, 23.85% at 2km/h, 33.52% at 3km/h, Calf muscle by 13.68% at 1km/h, 16.70% at 2km/h, 18.37% at 3km/h(p<0.05). Results : They show the significant difference in statistical figure. We've received the significant through the comparison between normal gait and assistive gait. These results will be utilized for the preliminary date in the future.

• Journal of Marine Bioscience and Biotechnology
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• v.3 no.1
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• pp.13-17
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• 2008

The Congo has a maritime coastline of 40 km, covering an area of $2,345,409km^2$. The fluvial system covers around $34,000km^2$ in a network of more than 33,000 km of rivers, principal tributaries, and streams. There are around 1,000 known species of fish, essentially freshwater and some brackish. The lakes of the Rift Valley contain the richest lacustrine fauna in the world. The family of Cichlidae alone has more than 900 species. At the same time, the lakes are profoundly different. Lake Tanganyika has 250 species of fish, of which 216 are endemic, whereas Lake Kivu contains only 32 and 16, respectively. A dense hydrographic network of water surfaces, inundated plains and lakes cover around $86,080km^2$ (3.5% of the national area) and have a considerable aquatic potential. The large peripheral lakes of the East cover around $48,000km^2$ of which 47% are under Congolese jurisdiction. The respective areas belonging to the Congo are: Lake Tanganyika, $14,800km^2$; Lake Albert, $2,420km^2$; Lake Kivu, $1,700km^2$; Lake Edward, $1,630km^2$; Lake Mo$\ddot{e}$ro, $1,950km^2$. Another two important lakes in the interior, Lake Tumba and Lake Mai-Ndombe, cover (between them) 2,300 and $7,000km^2$, depending on season (less in the dry season and more in the rainy season). There are also the lakes of the Kamalondo depression ($6,256km^2$), Lake Tshangalele ($446km^2$) and Lake N'Zilo ($280km^2$).