• Title/Summary/Keyword: natural streams

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The Analysis of Vegetation Characteristics According to Revetment Structure at Rural Small Streams (농촌지역 소하천의 제방형태에 따른 식생특성 분석연구)

  • Kim, Mi-Heui;Kang, Banghun;Kong, Min-Jae;Jeong, Myeong-Cheol;Son, Jin-Kwan
    • Journal of Wetlands Research
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    • v.17 no.4
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    • pp.359-369
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    • 2015
  • Stream ecosystems are highly valued natural resources, however, stream environments are currently under threat in several respects. We evaluated vegetation and ecological characteristics according to different revetment types. The distribution of vegetation differed with revetment type, with a 42~45 taxa found in natural revetments, and 23~38 taxa in vertical revetments. Thus, natural revetments host more diverse vegetation than vertical revetments. We also found more plants belonging to the families Labiatae and Cyperaceae growing in natural revetments than in vertical revetments. We proposed that habitat space be apportioned to introduce annual plants as part of stream restoration projects. And, we identified 7 families and 18 taxa of naturalized plants, majority taxa were either biennial or perennial. Moreover, naturalized ratio was higher in vertical(14.3%) than natural(12.1%), we proposed a plan to promote and improve natural streams and revetments. Furthermore, we applied a waterfront evaluation method developed by the Natural Resources Conservation Service of the USDA-NRCS, which confirmed that stream health can be improved in most regions by controlling naturalized plants and ensuring shrub and tree growth. We adopted a new method to remove naturalized plants and establish natural revetments to ensure shrub and tree growth to aid in small-stream restoration and improvement. In future studies, we hope to develop methods for small-stream restoration projects in rural areas.

Freshwater Tardigrades from Korea (한국 담수산 완보류)

  • Moon, Seung-Yeo;Kim, Won;Chang, Cheon-Young
    • Animal Systematics, Evolution and Diversity
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    • v.5 no.2
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    • pp.159-171
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    • 1989
  • Tardigrades were collected in freshwater habitats, such as rivers, streams , lakes , ponds and rice paddies at 19 different localities in Korea, during the period of May 1986 -January 1988, and seven species were identified. Dactylobiotus dispar, Macrobiotus hufellandi, M. richtersi, Hypsibius convergnes, H. dujardini, Isohypsibius granulifer, and Pseudobiotus megalonix, Five species of these except D. disparand H. dujardini, are new to Korea, which are fully described and illustrated.

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A Facial Expression Recognition Method Using Two-Stream Convolutional Networks in Natural Scenes

  • Zhao, Lixin
    • Journal of Information Processing Systems
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    • v.17 no.2
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    • pp.399-410
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    • 2021
  • Aiming at the problem that complex external variables in natural scenes have a greater impact on facial expression recognition results, a facial expression recognition method based on two-stream convolutional neural network is proposed. The model introduces exponentially enhanced shared input weights before each level of convolution input, and uses soft attention mechanism modules on the space-time features of the combination of static and dynamic streams. This enables the network to autonomously find areas that are more relevant to the expression category and pay more attention to these areas. Through these means, the information of irrelevant interference areas is suppressed. In order to solve the problem of poor local robustness caused by lighting and expression changes, this paper also performs lighting preprocessing with the lighting preprocessing chain algorithm to eliminate most of the lighting effects. Experimental results on AFEW6.0 and Multi-PIE datasets show that the recognition rates of this method are 95.05% and 61.40%, respectively, which are better than other comparison methods.

PWR Hot Leg Natural Circulation Modeling with MELCOR Code

  • Park, Jae-Hong;Lee, Jong-In;Randall. K. Cole;Randall. O. Gauntt
    • Proceedings of the Korean Nuclear Society Conference
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    • 1997.10a
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    • pp.772-777
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    • 1997
  • Previous MELCOR and SCDAP/RELAP5 nodalizations for simulating the counter-current, natural circulation behavior of vapor flow within the RCS hot legs and SG U-tubes when core damage progress can not be applied to the steady state and water-filled conditions during the initial period of accident progression because of the artificially high loss coefficients in the hot legs and SG U-tubes which were chosen from results of COMMIX calculation and the Westinghouse natural circulation experiments in a 1/7-scale facility for simulating steam natural circulation behavior in the vessel and in the hot leg and SG during the TMLB' scenrio. The objective of this study is to develop a natural circulation modeling which can be used both for the liquid flow condition at steady state and for the vapor flow condition at the later period of in-vessel core damage. For this, the drag forces resulting from the momentum exchange effects between the two vapor streams in the hot leg was modeled as a pressure drop by pump model. This hot leg natural circulation modeling of MELCOR was able to reproduce similar mass flow rates with those predicted by previous models.

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A Study on the Micro-Topography Landscape Characteristics and Waterfront Landscape Style of Waterfront in Korean Jingyeong Landscape Painting (겸재 정선의 진경산수화에 나타난 수변의 미지형 경관 특성과 하경양식)

  • Kim, Yong-Hee;Kang, Young-Jo
    • Journal of the Korean Institute of Landscape Architecture
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    • v.47 no.1
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    • pp.26-38
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    • 2019
  • This study is based on the analysis of the characteristics of waterfront scenery. Recently, waterfront development has expanded residentially, commercially and into leisure space. In the development of the waterfront, it is necessary to apply designs suitable for urban and various other waterfront areas. In this study, the natural scenery of the waterfront was researched with respect to the Korean Jingyeong landscape paintings and the main elements of the scenery were analyzed. In this study, 105 painting of Korean Jingyeong landscapes paintings were selected for the analysis of the waterside scenery. The paintings of Jeong Seon were studied to categorize streams topographically into mountainous, upper, middle, lower, and ocean types. In addition, major micro-topography elements, which are 13 water image elements and 13 staffage elements were analyzed. The main waterfront landscape elements are divided into 13 types. The waterfalls were divided into long waterfalls, short waterfalls, cascading waterfalls, and other aspects considered were line stream, curve stream, multi-curve stream, pond, water surface, flow surface, wave surface, rock side, pile sandy side, sandy side. There are 13 kinds of staffage elements, include pine forest, pine trees, fir trees, bamboo trees, willow trees, broadleaf tree, villages, houses, gazebo, boat, bridges, and people. The waterfront landscape by a river area was explained according to each characteristic of the waterfront landscape and staffage, and their changes were analyzed in each area. The 105 paintings were divided into 35 pieces of mountainous streams, 9 upper streams, 5 middle streams, 35 lower streams, and 21 oceans, and the change of each waterfront landscape and staffage was analyzed. Based on the topographical analysis of the waterfront landscape and staffage, the results can be summarized into 5 types of the waterfront landscape. Based on the micro-topographical characteristics of the waterfront landscape styles are as follow. In the mountainous streams, long waterfall and deep forest type are apparent, which depicts deep mountain waterfall scenery, and a multi-stream forest is the scenery of a picnic in the mountains, which is a representative form of mountainous streams landscape. In the upper-middle stream, the water-surface and gazebo type is predominant. In the lower stream, the sandy-gazebo typ scenery is predominant and the sandy depiction is unique to lower stream landscape. Pile sandy-dock type is life scenes where human activity highlighted, is a representative form of the lower stream landscapes. The characteristic of the coastal landscape is the serpentine rock scenery on the beach and the wave-serpentine rock type that forms the main coastal landscape. The study aims to propose significant design elements for a natural waterfront landscape planning based on the analysis of landscape in the paintings of Jeong Seon.

A New Species, Nazeris rutilicorpus (Coleoptera, Staphylinidae) in Korea (한국 좀딱지곰보개미반날개 (딱정벌레목, 반날개과)의 1신종)

  • Cho, Young-Bok
    • Animal Systematics, Evolution and Diversity
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    • v.17 no.1
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    • pp.141-144
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    • 2001
  • A new species, Nazeris rutilicorpus, of the subfamily Paederinae is described in Korea. This species is found from dead leaves near streams or forests. The illustrations of labrum, male abdomen and genitalia are presented. The differences between N. rutilicorpus and N. optatus (Sharp) are discussed.

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Determination of Representative Long-term Water Quality Parameters of the Streams in Estuarine Lake (하구호 유입하천의 유역특성에 따른 장기 대표 수질절정)

  • Kim, Young-Chul;Lee, Dong-Ryul;Hwang, Gil-Son
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.3
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    • pp.262-272
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    • 2005
  • This study was undertaken to obtain design concentrations for the natural system treating stream water flowing into estuarine lake(Sapgyo). This lake has three major, so called, national-class streams: one is Gokgyo flowing through two medium-size municipal areas and the others are Muhan and Sapgyo placed in mostly rural area nested with some small towns. The results of three year's investigation showed big changes in water quality during the period between dry and wet seasons. Nitrogen concentration usually decreases as the flow rate increases. The change of phosphorus concentration in Gokgyo was the same pattern as nitrogen, but in other two streams it was inversely related with flow rates. This is probably due to the chemical property of the particles washed out from the different stream basins during wet season. It was found that about 40 to 60% of the total nitrogen are in soluble form and on average, 35% of the total phosphorus consists of dissolved-P. Representative concentration of these streams has to be separately determined based on dry and wet season. TDS and SS could be indicating parameters useful to depict and characterize a change of water quality with respect to flow rate because their measurement is easy and also includes a small analytical error. TDS values measured during dry season are related with high nitrogen concentration while during wet season, SS values effectively reflect a high concentration of phosphorus. For design purpose, cumulative concentration distribution graph presented in this paper can be directly or indirectly applied to other streams through a brief comparative and verificative study.

Ichthyofauna of Stream on Goseong in Gyeongsangnam-do, Korea (경남 고성지역의 소하천 어류상)

  • Kim, Jun-Sop;An, Soon-Mo;Gwak, Woo-Seok
    • Korean Journal of Ichthyology
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    • v.26 no.4
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    • pp.322-330
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    • 2014
  • The fish species and groups were investigated at the four streams in Goseong from September 2011 to August 2012. During the survey period, 17 species from Goseong stream, 18 species from Maam stream, 20 species from Guman stream, and 15 species from Baedun stream of fish were collected. Four creek downstreams were classified into 2 groups which were categorized by the effects of seawater. Group A is Guman and Maam streams with no estuary barrage, with the exchange of freshwater and seawater. On the other hand, group B is Goseong and Beadun streams which was blocked by the estuary barrage and submerged weir. The former group was mainly consisted of peripheral freshwater fish species such as Tridentiger brevispinis, Gymnogobius castaneus, Mugli cephalus, and Acanthogobius flavimanus. The latter one was composed of primary freshwater fish species such as Zacco koreanus, Squalidus gracilis majimae, and Pseudorasbora parva. These results suggest that estuary barrage and submerged weir in the stream could change the natural flow of seawater and freshwater, resulting in change of fish species and groups.

Inquiry about the 'Baig Cheon' Stream with the Perspective of Environmental Studies for Water Environmental Education Program using Streams (소하천 물 환경교육 프로그램을 위한 백천에 대한 환경학적 탐구)

  • Kim, Jeong-Hwa;Lee, Du-Gon
    • Hwankyungkyoyuk
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    • v.23 no.4
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    • pp.82-95
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    • 2010
  • The Water Environmental Education Program Using Streams(WEES) is developed to help the teachers increase their professionalism of incorporating a local environment into their inquiry teaching. The purpose of this study is inquiry about the 'Baig Cheon' stream with the perspective of environmental studies for WEES. Through these studies, we tried to get the background information in 'Baig Cheon' and profound insights into application of WEES. The 'Baig Cheon' was examined from the perspective of environmental studies through literature study, field study, and water quality monitoring. The results revealed the characteristics of the 'Baig Cheon' that ran across a rural area in terms of the watershed boundaries, water systems, and water usage. The changes to the water quality items were observed according to the spatial distribution at the measuring points across the watershed for six months from March to August, 2007. The results indicate that the water quality of the 'Baig Cheon' could well be affected not only by the natural and environmental conditions such as the geological features, but also by the human activities including the land uses in the surrounding roads, rice fields and farms and the water supply and usage. The inquiry of the 'Baig Cheon' from the perspective of environmental studies will hopefully make the education and inquiry process of WEES more meaningful and in-depth and contribute to providing better environmental education that properly reflects the nature of inquiry from the perspective of environmental studies.

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A Comparative Study on the Preference and Visual Characteristics of Stream Landscape According to Hydromorpological Structures (하천의 물리적 구조에 따른 하천경관의 선호도 및 시각적 이미지 비교 연구)

  • Choi, Yun Eui;Lee, Jung A;Chon, Jinhyung
    • Journal of Wetlands Research
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    • v.15 no.3
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    • pp.301-315
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    • 2013
  • The purpose of this study is to investigate characteristics of hydromorpological structures that affect landscape preference and visual characteristics on the sections of the designated streams where have dynamic ecological characteristics. We evaluated the ecological status of the streams utilizing LAWA to assess hydromorpological structures of streams. We also investigated preference and visual characteristics of stream landscapes through Semantic Differential Scale(SD scale). The differences of visual images according to the characteristics of hydromorpological structures in the sites were analyzed by descriptive statistics, One-way ANOVA, and t-test. As a result, this study showed that sections represented as "good" ecological status are shown to be harmonious, beautiful, natural, and clean comparing to sections represented as "poor" ecological status. The hydromorpological structures that have significant impacts on the visual characteristics are considered as riparian vegetation, cross-sectional shape, and the artificial structures. Results of this study can help guide the stream restoration of the damaged stream to improving ecological function and positive landscape.