• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.247.2-247.2
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• 2014

플라즈마 전파 속도와 전자 온도를 조사하기 위해 ICCD카메라(Intensified Charge-Coupled Device Camera, 이하 ICCD)를 이용하여 대기압 저온 플라즈마제트의 방전 이미지를 촬영하였다. 사용된 플라즈마 제트 장치는 유리관 안에 주사기 바늘형 전극이 들어있는 형태이다. 전극의 내경은 1.3 mm, 외경은 1.8 mm, 총 길이는 39.0 mm이며 재질은 스테인레스강이다. 유리관의 내경은 2.0 mm, 외경은 2.4 mm, 총 길이는 80.0 mm이다. 입력 전압은 3.0 kV이며 구동 주파수는 40 kHz이다. 아르곤과 질소의 혼합가스 비율은 각각 100:1, 98:2, 95:5을 사용하였으며 총 가스유량은 400 sccm이다. 각각의 비율별로 군속도는 267 km/s, 305 km/s, 313 km/s이며 이온 음향 속도는 1.16 km/s, 1.24 km/s, 1.25 km/s이고, 전자 온도는 0.55 eV, 0.63 eV, 0.65 eV로 관찰되었다.

• Journal of Korean Library and Information Science Society
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• v.6
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• pp.105-140
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• 1979

This study is an attempt to present a model of the effective service area for branch library system planning in Dae Gu city as one of large urban public libraries in Korea. This model is built up through the analysis of the distribution of population and characteristics of community structure, based on the standard for the branch library system of a public library. The results are summarized as follows: 1. Under the circumstances of this country, each radius of the effective service area for branch libraries are as follows; $1{\sim}1.5km$. is adequate for the central library and major branches; 1km. for neighborhood branches; $0.5{\sim}0.8km$. for sub-branches. 2. Population within the radius of the effective service area of a given branch may range from 80,000 to 100,000 for major branches, from 50,000 to 60,000 for neighborhood branches, and from 20,000 to 30,000 for sub-branches. 3. The radius of the outer boundary for the effective service area may be between 4km. and 5km. from the heart of the city, and the inner boundary, 13.km. 4. Areas with the radius between 2km. and 3km. from the heart of the city may be selected as the most effective locations for branch libraries, and between 3km. and 4km. as the next priority. 5. The number of service areas may be 14, that is, 7 major branches(Sinam, Sinchun, Susung, Daemyung, Naedang, Dalsung, Rowon), 2 neighborhood branches (Pyungri, Nambu), and 5 sub-branches(Chimsan, Sangiuk, Bongduk, Hyomok, Dongchon)

• Journal of Korean Society for Geospatial Information Science
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• v.4 no.2 s.8
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• pp.15-22
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• 1996

As the exact geographical information has been nowadays required for effective developing and using of national land, in the country, there has been interested in using of GPS, and its practical use is expected. Various kinds of fundamental research for practical use of GPS is being accomplished. In this study, a test was carried out over 9 stations with baseline of the range of 1.5 to 210km, and the accuracy of baseline length by GPS relative positioning was variously considered. As result of this study, using a GPS receiving L1 frequency only, baseline accuracy for 2 hour observation was of the order of 0.3ppm for the 10km, and for I hour was below 1ppm. Using a GPS receiving dual frequency(L1/L2), baseline accuracy was of the order of 0.3ppm for the 100km to 200km as 3 hour observation using double difference methods by carrier phase. With basic on the result of this study, when observation and baseline processing are proceeded by the selected optimum observation time and using of baseline processing method, we can expect that geographical information will be acquired effectively.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2001.10a
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• pp.509-512
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• 2001

In this study, pollutant load from paddy field was estimated by regression equation from 5 to 8 in 2001. During study period, total rainfall was 511.3mm and runoff discharge was 968.71mm. Regression equation between flow rate(m3/s) and pollutant loading rate(g/s) is exponential relationship. For site 1, coefficient of determination (R2) for $COD_{cr}$, T-P, T-N were 0.7068, 0.8441, 0.6806 respectively and site 2, 0.9369, 0.8855, 0.4262 respectively. Considering unit loads, Jun was the highest valus as 13.85 $COD_{c}kg/km2/day$, 0.24 T-Pkg/km2/day, 1.22 T-Nkg/km2/day. Until study period, total $COD_{cr}$ load estimated regression equation is 19.32kg/km2/day and, T-P, T-N were 0.264, 1.88 respectively

• Korean Journal of Applied Biomechanics
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• v.17 no.3
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• pp.1-10
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• 2007

The purpose of this study was to examine the differences of lower limbs muscle activities depending on three walking speeds of 2.5km/h, 5.0km/h and 7.5km/h during forward walking and backward walking making 14 students the subjects of this study. To achieve this aim, surface electrodes for factor analysis of EMG were adhered to rectus femoris, biceps femoris, tibialis anterior and gastrocnemius medial head of right lower limbs. The conclusions through this study are as follows. 1) The muscle activity of rectus femoris was higher in backward walking group than in forward walking group and it was the highest at 7.5km/h walking speed. 2) The muscle activity of biceps femoris was higher in forward walking group than in backward walking group. It was the lowest at 5.0km/h walking speed and the highest at 7.5km/h walking speed. 3) The muscle activity of tibialis anterior was higher in backward walking group than in forward walking group. It was the lowest at 5.0km/h walking speed and the highest at 7.5km/h walking speed. 4) The muscle activity of gastrocnemius medial head was higher in backward walking group than in forward walking group except P2. It was the lowest at 5.0km/h walking speed and the highest at 7.5km/h walking speed.

• 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 Radiation Protection and Research
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• v.27 no.1
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• pp.11-19
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• 2002

The seasonal variation of $^7Be$ and $^{137}Cs$ concentrations in airborne dust, precipitation and dry fallout collected at Daejeon during the period of 1998 - 1999 has been studied. The annual mean values of 7Be concentrations in airborne dust, precipitation and dry fallout were in the range of $3.80{\sim}4.29\;mBq\;m^{-3},\;1.25{\sim}1.67\;Bq\;l^{-1},\;19.7{\sim}22.3 MBq\;km^{-2}$, respectively. The annual mean values of $^{137}Cs$ concentrations in airborne dust, precipitation and dry fallout ranged $1.08{\sim}1.28{\mu}Bq\;m^{-3},\;0.44{\sim}2.66 mBq\;l^{-1}\;\;0.036{\sim}0.0455\;MBq\;km^{-2}$, respectively. While the concentrations of $^7Be$ and $^{137}Cs$ in airborne dust and dry fallout were relatively higher in the spring and autumn when the amount of dry fallout increased than in other season, their concentrations in precipitation were relatively lower in the summer when the rainfall increased. The total depositions of $^7Be$ and $^{137}Cs$ due to dry fallout and precipitation were in the range of $80.7{\sim}137MBq\;km^{-2}$ and $0.059{\sim}0.060MBq\;km^{-2}$, respectively. More than 80% of $^7Be$ deposition resulted from precipitation, whereas about 60% of $^{137}Cs$ deposition was due to dry fallout.

• Journal of Ecology and Environment
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• v.29 no.3
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• pp.253-257
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• 2006

The objectives of this paper are to estimate home range and core habitat area of wild bores in Jirisan National Park of Korea. A radio-telemetry study was carried out on 5 wild boar individuals (3 females and 2 males). Except one individual whose enough data could not be collected, the mean home range size of 4 individuals was $5.13km^2$ (95% kernel) and mean core habitat area was $1.18{\pm}0.31km^2$ (50% kernel). Home-range sizes of 2 females were $6.21km^2\;and\;5.45km^2$ each, and that of 2 males were $5.15km^2\;and\;3.72km^2$ each, which means home-ranges of female boars were larger than those of male boars in this research. This result is presumed to have been caused by the fact that the males were sub adult individuals weighing 40 kg and 19 kg when they were captured for this research.

• Economic and Environmental Geology
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• v.18 no.2
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• pp.151-157
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• 1985

Events detected by the KIER microearthquake network operated in the Southern Part of Korea for 265 days in 1982~1984 were reviewed, and some of them were identified to be a dynamite explosion from several construction sites. The purpose of the present work is to determine the crustal structure of the Southern Korea using the time-destance data obtained from such explosion seismic records. The time·distance data can be well explained by a crustal model composed of four horizontal layers of which thickness, p and s-wave velocity ($V_p$ and $V_s$) are characterized as follows. 1st layer (surface) ; 0~2km, $V_p=5.5km/sec$, $V_s=3.3km/sec$ 2nd layer (upper crust) ; 2~15km, $V_p=6.0km/sec$, $V_s=3.5km/sec$ 3rd layer (lower crust) ; 15~29km, $V_p=6.6km/sec$, $V_s=3.7km/sec$ 4th layer (upper mantle) ; 29km~ , $V_p=7.7km/sec$, $V_s=4.3km/sec$ The relatively shallow crust·mantle boundary and low $P_n$ velocity compared with the mean values for stable intraplate region are noteworthy. Supposedely, it is responsible for the high heat flow in the South-eastern Korea or an anomalous subterranean mantle. The mean $V_p/V_s$ ratio calculated from the relation between p-wave arrival and s-p arrival times appears to be 1.735 which is nearly equivalent to the elastic medium of ${\lambda}={\mu}$. However, the ratio tends to be slightly larger with the depth. The ratio is rather high compared with that of the adjacent Japanese Island, and the fact suggests that the underlying crust and upper mantle in this region are more ductile and hence the earthquake occurrences are apt to be interrupted. As an alternative curstal model, a seismic velocity structure in which velocities are successively increased with the depth is also proposed by the inversion of the time·distance data. With the velocity profile, it is possible to calculate a travel time table which is appropriate to determine the earthquake parameters for the local events.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.541-542
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• 2011

한전의 가공 송전선로는 2010년 기준으로 약 12,990km(765 kV 송전선로 354 km, 345 kV 송전선로 약 3,868 km, 154 kV 송전선로 8,173 km, 66 kV 송전선로 : 약 595 km)가 설치되어 운전되고 있다. 이러한 송전선로는 평지, 구릉, 산악지 등에 설치됨으로써 자연환경에 크게 영향을 받는다. 특히 전 세계적으로 낙뢰에 의한 송전선로의 트립 고장이 전체 고장의 약 60%를 점유하는 것으로 보고되고 있으며, 낙뢰에 의한 고장을 최소화하기 위한 내뢰 설계를 시행하고 있다. 한전에서도 전압별 계통의 신뢰도와 경제성을 고려하여 765 kV 송전선로의 목표 사고율은 0.35[건/100 km 년], 345 kV 송전선로의 경우는 1.0[건/100 km 년], 154 kV 송전선로의 경우는 2.0[건/100 km 년] 이하의 목표 사고율을 설정하여 설계 운영하고 있다. 그러나 2000년 이후 낙뢰 발생 빈도가 증가하고 있으며, 낙뢰에 의한 고장 점유율도 약 75%로서 고품질 전력공급을 위한 내뢰 대책 수립의 검토가 요구되고 있다.