• Economic and Environmental Geology
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• v.37 no.4
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• pp.391-400
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• 2004

The purpose of this study is to analyze the geothermal anomaly based on the relationship between heat flow values and geologic settings in South Korea. For this, a total of 247 heat flow data was constructed to spatial database and the spatial database was overlaid with 1 : 1,000,000-scale digital geologic map using GIS. As the result, the average of heat flow is 64$\pm$14mW$m^{-2}$in South Korea. In the lithological aspect, the area of sedimentary rock shows high heat flow of 74mW$m^{-2}$, sedimentary/volcanic rock area 62mW$m^{-2}$, plutonic rock area 63mW$m^{-2}$ and metamorphic rock area 61mW$m^{-2}$. In the geologic time sequence, the Cenozoic strata has 91mW$m^{-2}$, the Mesozoic and Paleozoic strata 65mW$m^{-2}$, the Proterozoic strata 55mW$m^{-2}$ and the Archean strata 61mW$m^{-2}$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.1
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• pp.33-38
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• 2008

The probability of an oscillation occurrence in M/W frequency conversion repeaters is low on account of the different operating frequency of the input and output signals. The probability of interference caused by the M/W frequency conversion repeaters to other systems is also low because the systems are used in the line-of-sight. Therefore M/W frequency conversion repeaters are generally used for retransmitting the signal received from base station to the islands. This paper describes the design and implementation of analog predistorter for M/W frequency conversion repeaters in mobile communications. The M/W repeaters convert IF frequency of 1010+/-10MHz to RF frequency of 11GHz. A predistorter can be designed for the M/W repeater operating in either IF or M/W frequency. In this paper IF predistorter operated in 1010MHz is designed and implemented because a M/W predistorter operated in 11GHz is difficult to implement. The IF predistorter can linearize RF modules in the repeater followed by IF stages. The performance test results show that the implemented analog predistorter improves ACPR of 10dB at the output power of 25dBm with the signal frequency of 10.805GHz.

• Fire Science and Engineering
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• v.32 no.5
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• pp.6-14
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• 2018

This study was carried out with respect to the heat release rate (HRR) properties of building wood. Heat release characteristics were measured using a cone calorimeter (ISO 5660-1) with four kinds of wood. The time to ignition measured after the combustion in $25kW/m^2$ external heat flux was 35 to 55 s. Time to ignition of both lauan and red pine was marked with the most delayed value in each of 54 s, 55 s. The maximum heat release rate ($HRR_{peak}$) was $156.87{\sim}235.1kW/m^2$, and the risk of early fire was highest in spruce. Total heat release of red pine was obtained in the highest value with $114.2MJ/m^2$. The mean effective heat of combustion of Japanese cedar was 19.1 MJ/kg and the highest among the samples. Fire risk of wood by FPI was orderly increased from lauan ($0.2468s{\cdot}m^2/kW$), red pine ($0.2339s{\cdot}m^2/kW$), spruce ($0.2308s{\cdot}m^2/kW$) to Japanese cedar ($0.2231s{\cdot}m^2/kW$). Fire risk of wood by FGI get increased from lauan ($0.5088kW/m^2{\cdot}s$), red pine ($0.5111kW/m^2{\cdot}s$), Japanese cedar ($2.8522kW/m^2{\cdot}s$) to spruce ($3.0662kW/m^2{\cdot}s$). Therefore, the risk of fire on the heat release characteristics of woods were found that spruce and Japanese cedar showed the high value compared with the other specimens.

• Economic and Environmental Geology
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• v.40 no.6
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• pp.761-769
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• 2007

We made 712 thermal property measurements on igneous, metamorphic and sedimentary rock samples from Gyeonggi-do, Gangwon-do and Chungchung-do, Korea. The average thermal conductivities of igneous, metamorphic and sedimentary rocks are 3.58W/m-K, 4.16W/m-K and 4.53W/m-K, respectively. Thermal conductivity of granite and gneiss are 2.13-5.87W/m-K and 2.26-6.67W/m-K, with average values of 3.57W/m-K and 3.945W/m-K, respectively. The average of thermal diffusivities are $1.43mm^2/sec\;and\;1.55mm^2/sec$, respectively; the average of specific heat values are 0.914J/gK, 0.912J/gK for granite and gneiss samples, respectively. The thermal conductivity of a rock type generally have a wide range because it depends on various factors such as dominant mineral phase, micro-structure, anisotropy, and so on.

• Korean Journal of Acupuncture
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• v.23 no.1
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• pp.1-14
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• 2006

Objectives : This research was performed to investigate the effect of invasive low level laser acupuncture therapy(LLLAT) at Yolgyol+yogu(LU7+LR5) on weight gain, food intake, food efficiency, lipid metabolism and liver function in hyperlipemia rats. Methods : Experimental groups were divided into high fat diet cup(Control group), high fat diet and 15 mW/5 min LLLAT at LU7+LR5(15 mW/5 min group), 15 mW/10 min LLLAT at LU7+LR5(15 mW/10 min group), 30 mW/5 min LLLAT at LU7+LRS(30 mW/5 min group), 30 mW/10 min LLLAT at LU7+LR5(30 mW/10 min group). LLLAT was treated at the 15,30mW-5,10min once a 2day during 5 weeks. Results : Body weight was decreased significantly in 30 mW/s min group and 30 mW/10 min group compared with control group. Food intake was decreased significantly in 15 mW/5 min group and 15 mW/10 min group compared with control group. Food efficiency was decreased significantly in 30 mW/10 min group compared with control group. In the lipid metabolism, total cholesterol, HDL-cholesterol and free fatty acid were increased significantly in 15 mW/5 min group and 30 mW/10 min group compared with control group. LDL-cholesterol was increased in 30 mW/10 min group and phospholipids was decreased significantly in all experimental group compared with control group. triglyceride was not showed significant result in all experimental group. In the liver function, AST was not showed significant result in all experimental group, ALT and ALP were increased significantly in 30 mW/10 min group, ALP was decreased in 30 mW/5 min group compared with control group. Conclusions : LLLAT at LU7 and LR5 can manage hyperlipemia by controlling body weight, food intake, food efficiency ratio and lipid metabolism.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.456-459
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• 2007

Thermal conductivities (TC) of 57 Jurassic muscovitic granite samples (KIGAM) and 149 porphyritic granite samples (Yeonki: BE-2, BE-3) were measured with LFA-447. Ranges of TC values are $2.429{\sim}3.878$ W/mK (KIGAM), $2.220{\sim}3.767$ W/mK (Yeonki, BE-2) and $2.019{\sim}3.990$ W/mK (Yeonki, BE-3); arithmetic means are 2.924 W/mK (KIGAM), 2.907 W/mK (Yeonki, BE-2), and 2.881 W/mK (Yeonki, BE-3), respectively. In this study, harmonic mean values were calculated to estimate the average value of TC. Harmonic mean values are 2.883 W/mK (KIGAM), 2.886 W/mK (Yeonki, BE-2), and 2.866 W/mK (Yeonki, BE-3), respectively. Heat extraction rates of a borehole heat exchanger strongly depend on TC values. Heat-extraction rates from re values are expected to be a little lower than 84 W/m in all sites. However, considering ground water flow, it is expected that actual heat extraction rate would be higher than the expected value.

• Bulletin of the Korean Mathematical Society
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• v.52 no.2
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• pp.549-556
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• 2015

In this paper, we characterize w-Noetherian modules in terms of polynomial modules and w-Nagata modules. Then it is shown that for a finite type w-module M, every w-epimorphism of M onto itself is an isomorphism. We also define and study the concepts of w-Artinian modules and w-simple modules. By using these concepts, it is shown that for a w-Artinian module M, every w-monomorphism of M onto itself is an isomorphism and that for a w-simple module M, $End_RM$ is a division ring.

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.166-166
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• 2008

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.230.2-230.2
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• 2008

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.497-500
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• 2007

지열류량은 지열자원 개발 시 지열 이상대를 찾는데 있어서 중요한 자료로 사용된다. 우리나라의 지체구조별 지열류량 평균은 경기육괴 66 $mW/m^2$, 옥천습곡대 65 $mW/m^2$, 영남육괴 60 $mW/m^2$, 경상분지 72 $mW/m^2$, 연일분지 75 $mW/m^2$이다. 이러한 대륙 내의 지표 지열류량은 상부 지각내의 방사성 동위원소 붕괴에 의한 열생산율(${\sim}40%$)과 하부지각 및 상부맨틀에서부터 전도되어 올라온 지열류량(${\sim}60%$)으로 설명할 수 있다. 따라서 지열류량의 결정에 있어서 열생산율의 정보는 중요한 부분을 차지한다. 열생산율은 지각 내에 존재하는 주요 방사성 동위 원소인 U, Th, K의 붕괴열에 의한 것이며, 열생산율의 측정은 gamma-ray log 자료를 이용하는 방법과 화학분석을 통한 방법이 있다. 이 연구에서는 두 가지 방법을 이용하여 총 123개(화강암 86개, 편마암 37개) 지점에서의 열생산율을 산출하였다. 화강암의 열생산율 평균은 2.15 ${\mu}W/m^3$이며, 편마암의 열생산율 평균은 2.22 ${\mu}W/m^3$로 나타났다. 지체구조별 열생산율의 평균은 경기육괴 2.52 ${\mu}W/m^3$, 옥천습곡대 2.16 ${\mu}W/m^3$, 영남육괴 2.35 ${\mu}W/m^3$, 경상분지 2.01 ${\mu}W/m^3$로 나타났다. 지체 구조별 열생산율과 지열류량의 상관성 분석에서 우리나라의 경우 지열류량이 높은 지역에서 열생산율이 낮은 경향을 보인다. 따라서 열생산율이 지표 지열류량을 결정하는데 있어서 가장 중요한 요소가 아님을 확인할 수 있다.