• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 1998.10a
• /
• pp.251-254
• /
• 1998

본 논문에서는 신경회로망의 수렴속도를 높이기 위한 알고리즘을 제안한다. 전형적인 역전파 학습방식은 느린 수렴속도가 단점으로 제기되는데 이는 비용함수의 계곡부근에서 가중치의 궤적이 심한 진동현상을 보이기 때문이다. 이 문제를 해결하기 위해서 본 논문에서는 경사법에서 사용되는 갱신방향을 계곡의 진행방향을 이용하여 변경한다. 모의실험을 통하여 제안된 방법으로 가중치의 궤적에 나타나는 진동을 줄이고 수렴속도를 향상시킬 수 있음을 보인다.

• Korean Journal of Environment and Ecology
• /
• v.16 no.4
• /
• pp.409-420
• /
• 2003

The avifauna of from Manbokdae to Siribong in Jiri Mountain part of Baekdudaegan, was surveyed from May to November, 2002. In total, we observed 901 birds, and they were consisted of 49 species,23 families and 7 orders. The largest number of birds were observed in valley and followed by in low ridge, Road, Agricultural area and high ridge. The dominant species were Great Tit (Parus major) and then Brambling (Fringilla montifringilla), Tree Sparrow (Passer montanus), Black-billed Magpie (Pica pica) and Long-tailed Tit (Aegithalos caudatus). The highest species diversity index was 2.85 at low ridge(846m), and the lowest was 1.83 at high ridge(1,433m). In this study, the valley is the most important area for the habitat of birds and followed by the low ridge and agricultural area. Thus, to decide the management required area of Baekdudaegan, it should include valley and nearby lowland as well as ridge area. Moreover, there should be some sort of restriction of vehicle usage when a road cross or close to the Baekdudaegan.

• Korean Journal of Environment and Ecology
• /
• v.7 no.2
• /
• pp.181-186
• /
• 1994

The Shindae resting place-Jibong valley forest in Tokyusan area was studied to investigate forest structure in relation to altitude and part of slope. Forty eight quadrats were set up in the valley forest along altitude of 750m to 1,247m and part of the slope. Density of trees in tree strata decreased as increasing elevation, and mean DBH of trees in tree strata increased as increasing elevation. With increasing elevation the importance values of Quercus mongolica, Acer mono, Fraxinus mandshurica increased, while those of Quercus serrate, Betula schmidtii decreased. As going from lower part to upper part of the slope, the importance values of Quercus mongolica and Symplocos chinensis for. pilosa increased while those of Cornus controversa and Fruxinus mandshurica decreased. The number of species, species diversity and evenness tended to decreased as increasing elevation. The range of similarity indices between elevation belts, and parts of the slope were 55.3~67.1％ and 36.8~71.7%, respectively. According to importance value and cluster analysis, the studied valley forest was classified into four forest communities of Quercu serrata community of lower part of slope of low elevation belt, Quercus mongolica-Quercus serrata community of middle and upper part of slope of low elevation belt, Quercus mongolica-deciduous tree species community of middle and high elevation belt and Quercus mongolica-Rhododendron schzippinbachii community of the top area.

• Korean Journal of Environment and Ecology
• /
• v.15 no.4
• /
• pp.401-407
• /
• 2002

Fishfauna were investigated in the Taebaeksan area streams. At the upper tributary of the Han River, 8 species of 4 families were collected and the dominant species was Rynchocypris oxycephalus. The two species, Rynchocypris kumgangensis and Silurus microdorsalis were Korean endemic species. Brachymystax lenok tsinlingensis, designated as a natural monument and vulnerable species was confirmed at the Jeongam-sa area streams At the upper streams of the Nakdong River, collected fishes were identified as 14 species of 7 families. The dominant Species was R. oxycephalus and subdominant Zacco temmincki. Korean endemic species were 8species(51.7%), Coreoleuciscus splendidus, Squalidus gracilis majimae, Microphysogobio yaluensis, Niwaella multifasciata, Silurus microdorsalis, Liobagrus mediadiposalis, Coreoperca herzi and Odontobutis platycephala. Brachymystax lenok tsinlingensis were confirmed at the Hyundong-Chon Stream and Baek-chon stream.

• Journal of the Korean Geotechnical Society
• /
• v.26 no.5
• /
• pp.49-55
• /
• 2010

The large scale rock falling had occurred on 22nd February, 2007 in the Cheongbuldong valley area of Seoraksan National Park, and the visiting pass had been closed for a while. Similar cases of rock falling have occurred in the latest years according to a great variety of crack, joint, weathering of solid rock and surface water caused by a recent climatic change in the Seoraksan National Park. In this study, rock falling energy was estimated and the movement of rockslide was analysed based on detailed investigation on large scale rockslides occurring at the spot 80 m high from the bottom of the valley. From analysing results, the effective management method for rock falling was proposed. The method could minimized the dangerous factors with no change of natural environment of the National Park.

• Journal of Korean Society of Environmental Engineers
• /
• v.34 no.7
• /
• pp.454-458
• /
• 2012

The Characteristics of small scale water works at west Gyeong-nam was analyzed by investigationg the 6,569 cases which were carried out from Jan. 2005 to Dec. 2010. The result of the research about treated water quality the highest mean concentration of fluorine was 0.19 mg/L at Hamyang the highest mean concentration of Nitrite nitrogen was 3.7 mg/L at Namhae each the highest mean concentration of Hardness, Total solids, Sulfate was 177 mg/L, 271 mg/L, 80 mg/L at Uiryeong. In the case of waterworks originated from valleys, the total bacterial count and turbidity were higher than ones originated from groundwater. On the other hand, nitrate nitrogen, total solids, hardness, sulfate, fluorine and iron were detected more than ones originated from valleys.

• Ecology and Resilient Infrastructure
• /
• v.4 no.2
• /
• pp.75-82
• /
• 2017

This study was executed to know the effect of the habitat size on huanren brown frog (Rana huanrensis) larvae's growth. We've conducted the study on Mt. Surak in Sanggye-dong, Nowon-gu, Seoul. Our study site was discriminated the huanren brown frog larvae's habitat into the three different areas, such as small area (S1, $3.91m^2$), middle area (S2, $4.42m^2$), and large area (S3, $38.37m^2$) in the same water channel. We measured two times per a week the 15 huanren brown frog larvae's body length, and developmental stages (foreleg, hind leg, tail length) including the environmental factors (humidity, air temperature and water temperature) of the study site from March 30 to June 28 in 2016. The only hatching rate was measured for the three egg sacs at the S2 study site. We found that the average hatching rate was $76.84{\pm}18.23(%)$ at S2. Generally, because of less precipitation during our study periods, all habitat areas for our study site were gradually decreased. The middle area, S2, was not reduced, the small area, S1, was reduced more than a fourth, and the largest area, S3, was drastically reduced more than half from initial area. There was no statistically difference among the three study sites for the three environmental factors (average humidity, average air temperature, and average water temperature) by F-test, but there were significant difference among the three site for the larvae's body length (F-test p< 0.05). Therefore, the larger of habitat areas, the larger of the larvae length as well as the faster of the larvae's developmental stages. When we measured the body lengths of immature huanren brown frogs, the immature frog of S1 was smallest, the immature frog of S3 was middle lenght, and the immature frog of S2 was largest. There were statistically different among the three study sites for the immature huanren brown frogs (F-test, p< 0.05). Because the S2 study site was relatively stable without rarely changing the study area, it meant that huanren brown frog was sensitive to habitat areas. Based on the results of this study, if we study on the effect of the altitude on the growth rate of huanren brown frog, it must be helpful in understanding the habitat environment of the population of huanren brown frog.

• Korean Journal of Environment and Ecology
• /
• v.12 no.4
• /
• pp.373-380
• /
• 1999

The Byokryon-Daejangbong valley forest in Keumsan area at Hallyo-Haesang National Park was studied to investigate forest structure in relation to altitude and part of the slope. Forty-eight quadrats were set up in the valley forest along altitude of 200m to 650m and part of the slope. Density, mean DBH, and basal area of the canopy trees were 820~1873trees/ha, 10.7~14.6cm, and 17.7~22.2$\m^2$/ha, respectively. With increasing elevation mean DBH and basal area of tree stratum increased while density of tree stratum decreased. As elevation increased the importance values of Quercus mongolioa, Styrax japonica, Acer pseudo-sieboldiannum, and Sorbus alnifolia increased while those of Pinus thunbergii, Pinus densiflora, Prunus sargentii, Cornus kousa, and Eurya japonica decreased. The importance values of Fraxinus sieboldiana, Quercus variabilis, and Sorbus alnifolia increased as going from lower part to upper part of the slope. However, the opposite trend was found for the importance values of Styrax japonica, Lindera erythrocarpa, and Zelkova serrata, With incresing elevation number of species, species diversity, and evenness incresed and it was suggested that man interference was relatively severe. The range of similarity indices between elevation belts and between parts of the slope were 42.0~71.8% and 74.8~76.8%, respectively. According to importance values and cluster analysis, the studied valley forest was classified into four forest communities of Quercus serrata-Pinus densiflora community in low elevation belt, Carpinus laxiflora-deciduous tree species community in high elevation belt and lower and middle parts at middle elevation belt, Quercus variabilis-Carpinus laxiflora community in upper part at middle elevation belt, and Quercus mongolica-Styrax japonica community in top area. There were significantly positive correlation among Quercus serrata, Pinus densiflora, Pinus thunbergii, and Eurya japonica and among Carpinus laxiflora, Zelkova serrata, and Cornus walteri.

• Korean Journal of Environment and Ecology
• /
• v.32 no.6
• /
• pp.582-590
• /
• 2018

Although there are many studies of the effect of climate change on the breeding phenology and community diversity of amphibians, the studies of variations in reproductive population size of individual species according to climate change are still lacking. We examined the effect of climate change on the reproductive population size of Rana huanrenensis and Hynobius leechii, which bred in mountain valleys, by surveying the reproductive population of the two species between 2005 and 2012 and analyzing the correlation between the variation of the outdoor population and the surrounding climate change factors, obtained from a meteorological observatory located at 5.6 km from the study site. The size of the reproductive population of the two species commonly fluctuated with aan pproximately 3.5-year cycle. That of H. leechii, in particular, decreased significantly over eight years. The air temperature tended to more closely relate with the reproductive population size of R. huanrenensis as was the case of the precipitation with that of H. leechii. The yearly mean highest temperature and spring mean temperature variation consistently decreased over the eight years, and the latter was related with the significantly decreased size of H. leechii reproductive population. These results showed that recent climate change directly could affect the reproductive population size of amphibians, particularly H. leechii, which breeds in mountain valleys.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2022.05a
• /
• pp.448-448
• /
• 2022

기후변화와 산업의 발달로 필요한 수자원의 양은 증가하고 있지만 수자원의 양은 줄고 있어 가뭄 피해에 대해서 더욱 취약해지고 있다. 특히, 우리나라의 물 공급 소외 지역 중 산간지역은 계곡수 등을 이용한 소규모 용수 공급 시설을 이용하고 있다. 산간지역은 지형적 특성상 수자원의 저류가 힘들어 가뭄 피해에 더욱 취약하다. 산간지역에 적용할 수 있는 수자원 공급방안 중 지형의 경사를 이용하여 샌드댐을 설치하여 수자원을 확보하는 방안은 이에 대한 하나의 대안이다. 본 연구에서는 연구지역인 춘천시 물로리 현장을 모사한 샌드댐 물리 모형을 구축하였다. 샌드댐 물리 모형의 구축은 현장의 경사에 대비하여 1/15 규모로 축소하였으며, 현장의 유하 순서와 동일하게 구성하였다. 춘천 물로리 현장에서는 기존 취수원에서 샌드댐으로 유입되는 수량과 배후 지하수에서 유입되는 수량으로 나누어 샌드댐 모의를 진행하였다. 샌드댐을 이용한 산간지역의 물공급과 운영 방안을 통해 물 공급 소외지역에서 활용가능한 대안을 제시하였다.