• Journal of the Korean Geotechnical Society
• /
• v.19 no.5
• /
• pp.99-107
• /
• 2003

Moisture flow and heat flow within pavement systems have been recognized as coupled processes with complex interactions between them. The distribution of moisture and temperature within pavement due to the moisture flow and heat flow varies not only seasonally but also vertically and horizontally. This paper presents an analysis model by the finite element method for the two-dimensional coupled moisture and heat flow in unsaturated soils. To test the model the analysis result by the model is compared with the analysis result by the software, GEO-SLOPE developed by GEO-SLOPE International Ltd. in Alberta, Canada. And a sensitivity analysis using ASTM method is performed to identify how model inputs affect the modeling analysis.

• Journal of Energy Engineering
• /
• v.8 no.4
• /
• pp.567-575
• /
• 1999

This study found potential ability to generate electric power using difference in water temperature between sea surface water and deep water in the East Sea which includes the East Sea Proper Water with the temperature less than 1$^{\circ}C$ throughout a year without seasonal variation. To quantify the difference in water temperature between sea surface water and deep water in the East Sea. We computed the annual mean ($^{\circ}C$), the annual amplitude ($^{\circ}C$), the annual phase (degree) and the duration time which showed more than 15$^{\circ}C$ temperature difference from the water temperature data using Harmonic analysis during 1961~1997. The best place for generating electric power in the East Sea seems to be the eastward ocean areas (36$^{\circ}$ 05'N, 129$^{\circ}$ 48'E~36$^{\circ}$ 05'N, 130$^{\circ}$ 00E'E) from Pohang city. The annual mean of the difference in water temperature between sea surface water and 500 m depth was 24$^{\circ}$C at the place to generate electric power in August according to the data of 1961~1997. the maximum duration periods with more than 15$^{\circ}C$ temperature difference were 215 days (5/5-12/10) a year in the place mentioned electricity with a stable plan. In the East Sea coastal areas of the Korean peninsula, the average minimum depth to reach the East Sea Proper Water from surface water is 300 m and fluctuates between 250 m and 350 m throughout a year. Further studies could be needed for the utilization of cold water, such as the East Sea Proper Water for energy conversion.

• Korean Journal of Heritage: History & Science
• /
• v.42 no.1
• /
• pp.158-186
• /
• 2009

The Gossi Cave, Natural Monument 219, extends horizontally for 3,388m with 215m elevation. 620m of the horizontal cave length was opened to the public in 1974. The Gosu Cave, Natural Monument 256, also was opened the public for only 685m of the horizontal cave length, 1,700m, in 1976 in order to preserve its ecological cave environment. The surface of the speleothems in two caves have been turning black due to pollutants after the caves were opened to the public. The degrees of temperature, humidity and partial pressure of carbon dioxide in the caves were related the seasonal variation. Specially, the value of partial pressure of carbon dioxide($CO_2$) in the cave higher in the summer than any other seasons. The partial pressure of $CO_2$ continues to build in the summer because of exceed the self-purification limit in the caves. The value of $CO_2$ variation in the caves was mainly controlled by the amount of visitors. As a result, we have to controlled the amount of visitors to preserve the cave environment.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2008.05a
• /
• pp.120-124
• /
• 2008

본 연구에서는 대기대순환모형(GCM) 모의결과를 활용하여 한반도 지역의 강수량과, 온도에 대하여 분위사상법(Quantile mapping)과 상세화기법(downscaling)을 적용하였다. GCM 모의자료는 캐나다기후센터(CCCma; Canadian Centre for Climate Modeling and Analysis)의 CGCM2 A2, B2시나리오의 $2001{\sim}2100$년 자료를 사용하였으며, GCM 모의결과값과 국내관측값과의 계통적오차(systematic bias)를 보정하기 위하여 분위사상법을 적용하였다. 강수자료의 경우 한반도의 강수특성을 반영하기 위하여 홍수기, 비홍수기로 구분지어 감마분포를 이용하였고, 온도자료의 경우 계절적 특성을 반영하기 위하여 봄/가을, 여름, 겨울로 구분지어 표준정규분포를 이용하여 분위사상법을 적용하였다. 강수자료의 경우 과거($1965{\sim}1989$:25개년)의 31개소의 일평균강우 자료를, 온도자료의 경우 과거($1965{\sim}1989$)의 11개소의 일평균온도 자료를 사용하였다. 이러한 분위사상법의 적용으로 GCM 모의결과값과 관측값사이의 계통적오차를 보정하였으며, 그 결과 강수자료의 홍수기의 경우 모의결과값과 관측값의 차이가 3.79mm/day에서 0.62mm/day로, 비홍수기의 경우 0.24mm/day에서 0.02mm/day로 각각 83%, 92% 보정된것을 확인하였으며, 각각의 확률분포 매개변수를 추출하였다. Random Cascade 모형의 자기유사성 및 무작위 변동성계수를 추정하기 위하여 2002년 8월 6일 00:10부터 8월 9일 24:00까지 432장의 레이더 스캔을 사용하여 스케일분석을 실시하였으며, 모형적용결과 연평균 강우량의 변화는 A2의 경우 797.89mm에서 1297.09mm로 B2의 경우 815.02mm에서 1383.93mm로 나타났다.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.35 no.1
• /
• pp.129-139
• /
• 2015

Concrete-Face Rock-Fill Dams (CFRDs) are rock-fill dams with watertight-concrete slabs on its upstream slope instead of its central earth cores. The design for CFRDs are still largely empirical and typically based on past experiences. This paper presents a description of the concrete face slabs and leakage behaviors of two post-constructed CFRDs based on the data gathered through instrumentation during the initial impoundment. The results show that the strain on the concrete face slab and the horizontal displacements of the vertical slab joints are slightly affected by both the seasonal temperature change and water loading during the initial impoundment. The deformation of perimetric joints are less affected by the temperature change, however it is significantly affected by the water loading during the initial impoundment. The leakage rate is significantly affected by the hydrostatic load and the deformation of the perimetric joints.

• Horticultural Science & Technology
• /
• v.16 no.3
• /
• pp.377-380
• /
• 1998

In order to investigate the effects of foliage plants on the changes of indoor thermal- and hygro- environments, experiments were carried out in two rooms with similar physical factors. Changes of indoor environmental parameters according to the existence of plants, their arrangement methods, and the existence of wrapseal for protecting the loss of water from the pot soil were measured during certain periods in winter and summer season, using Pachira aquatica which is widely used as indoor plant and has higher photosynthetic and traspiration rate than other foliage plants. The data suggested that the existence of plants didn't affect directly on the indoor thermal environment, while relative humidity increased about 3~5%, regardless of season, by putting plants which had volume equivalent to 2.4% of room volume. In summer, there was no difference in increasing effect of relative humidity between parallel arrangement with window and spread arrangement in the room, but in winter the former arrangement was more effective than the later.

• Korean Journal of Poultry Science
• /
• v.15 no.2
• /
• pp.115-145
• /
• 1988

우리나라 축산업이 과학적인 축산으로 변모하는 과정에서 선도적 역할을 해온 것이 양계분야인 만큼 생산성적에 있어서도 어느 타 선진국에 뒤지지 않을 만큼 높아지고 있다. 그러나 사료원료의 해외 의존도가 높고 개방경제시대에 접어들음으로서 외국의 양계산물과 경쟁을 벌리게 되는 이 시점에서 생산비중 가장 높은 비율을 차지하는 사료를 가장 경제적으로 이용함으로서 생산 효율을 극대화시킬 책임이 우리에게 있다. 우리나라의 년 중 기온차이가 심하고 대부분의 산란계가 유창계사에서 사육되고 있는 만큼 계절에 따른 온도 변화에 맞추어 계절 사양을 함으로서 하절기에는 영양소 결핍현상을 방지하고 동절기에는 영양소 과다 섭취로 인한 영양소 허실을 줄일 수 있다. 난중에 따른 난가 형성이 되는 시장 상황에서 난중을 조절함으로서 생산효율을 높일 수 있다. 비록 난중이 생리적인 현상에 의해서 결정되지만 닭이 섭취하는 아미노산과 지방의 함량을 증감함으로써 어느 정도의 난중조절이 가능하다. 산란율과 난중에 영향을 미치지 않는 범위에서는 산란계의 체중이 작을수록 경제성이 있다. 가급적 육성기간중의 사료비를 줄이고 성계 체중을 줄이는 방법으로 육성기간중의 사료비를 줄이고 성계 체중을 줄이는 방법으로 육성기간중 단백질 점증법이 시험되고 있다. 이러한 육성체계를 보급화 하기에 앞서서 좀 더 많은 비교 시험이 필요하리라 본다. 사료 원료의 영양가를 정확하게 평가하는 것은 닭이 필요로 하는 영양소 요구량을 충족시키기 위한 필수조건이 된다. 단지 영양성분의 화학분석만으로 사료배합에 임하지 말고 생물가를 측정함으로서 닭이 섭취하는 영양소의 이용률이 함께 고려하여야 한다.

• 한국해양학회지
• /
• v.18 no.1
• /
• pp.43-48
• /
• 1983

Oceanic temperature inversions, with unstable stratifications, are frequently founed in the surface layer of a few tens meters in the Japan Sea and the Yellow Sea in Winter. Mechanisms responsible for the generation of temperature inversions include the followings: (1) The nat heat loss at the sea suface requires an upward transport of heat from the interior of the ocean y convection, and this convection leads to the temperature inversions. (2) The downward propagation of the annual variation of the sea surface timperature, with an exponential decrease of amplitude and a linear change of phase with depth, generates the surface inversion layer in winter. (3) The cold water cdvection by Ekman drift, of which magnitude decreases exponentially with depth, generates temperature inversions for the three possible mechanisms mentioned above.

• Journal of Astronomy and Space Sciences
• /
• v.15 no.1
• /
• pp.139-150
• /
• 1998

We measured the terrestrial nightglow of OI $6300{\AA}$ in the thermosphere (~250km) using a ground-based Fabry-Perot interferometer at the King Sejong Station, Antarcticfrom March through September, 1997. The King Sejong Station is located at high latitude geographically ($62.22^{\circ}S,\;301.25^{\circ}E$) but at mid latitude geomagnetically ($50.62^{\circ}S,\;7.51^{\circ}E$). It is therefore the strategic location to measure the temperatures of the thermosphere in the Southern Hemisphere associated with both solar and geomagnetic activities. In this study, we analyzed the observed temperatures inrelation to F10.7 and Kp indices to examine the effect of the solar and the geomagneticactivities on high-latitude neutral thermosphere. During the observing period, the solaractivity was at its minimum. The measured temperatures are usually in the range between about 600~1000 K with some seasonal variation and are higher than those predicted by semi-empirical model, VSH (Vector Spherical Harmonics) and empirical model, MSIS (Mass-Spectrometer-Incoherent-Scatter)-86.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2006.05a
• /
• pp.485-488
• /
• 2006

SLA and SST is high in summer and fall, it is low in spring and winter. The clearly annual period shows through the power spectrum density. A semi-annual period and seasonal period appeared, In. At sea surface variation of satellite data(Mean Sea Level Anomaly) and in-situ data, coefficient-correlation show 0.323 at Mukho which is located in the coastal. Chujado and Ulleungdo is a 0.685 and 0.780, retentively. A coefficient-correlation of SST show higher than sea surface variation as Mukho-0.920, Chujado-0.894 and Ulleungdo-0.815. A comparison between SST and MSLA show 0.77, SST appeared faster about 1 to 3 months than MSLA.