• Title/Summary/Keyword: terraces

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UV-LASER INDUCED SURFACE REACTION - DESORppTION AND ETCHING

  • Murata, Yoshitada
    • Proceedings of the Korean Vacuum Society Conference
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    • 1992.02a
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    • pp.3-10
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    • 1992
  • pphotostimulated desorpption of NO chemisorbed on ppt(001) at 80K has been studied by the (1+1)-resonance-enhanced multipphoton ionization((1+1)-REMppI) technique. A linearly ppolarized ArF excimer laser ( =193 nm, 6.41eV) is used as the ppumpp laser. A high adsorpption rate selectivity was found in the expposure deppendence of the NO desorpption yield. The NO desorpption yield increases drastically when the amount of NO expposure exceeds ~1.8 L. This result shows that the amount of NO sppecies with a large cross section for pphotostimulated desorpption increases drastically at higher NO coverages. Using scanning tunneling microscoppy, we have observed structural modifications of the chlorinated Si(111)-7$\times$7 surface induced by 266nm laser irradiation. At very low laser fluence of 0.7mJ/$\textrm{cm}^2$, at which thermal desorpption can be ignored, a pperiodic stripped ppattern of a single domain is imaged. This ppattern consists of flat terraces and narrow grooves of ~60 and ~10A in width, resppectively.

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Geomorphic Development of River Terraces at the Mid.Downstream of Hongchoen River (홍천강 중.하류의 하안단구 지형발달)

  • 윤순옥;이광률
    • Journal of the Korean Geographical Society
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    • v.35 no.2
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    • pp.189-205
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    • 2000
  • 북한강 지류 홍천강은 중류구간과 하류구간의 하천 형태가 대조적이다. 홍천강의 중류는 단층선을 따라 직선상으로 남서류하고, 하류는 감입곡류 구간으로 서류하여 북한강에 합류한다. 유역분지의 기반암은 중류구간의 서쪽과 하류구간은 편마암, 중류구간의 동쪽은 화강암이며, 상류구간은 변성암과 화강암이 혼재한다. 하안단구는 중류구간 유로의 양안에서 넓게 분포하며, 하류구간에서는 감입곡류의 활주사면에 좁게 나타난다. 이러한 특징은 지질구조선의 존재, 중류와 하류의 지질 특성과 이에 따른 유로 발달의 차이에 기인한다. 화계분지는 중류구간의 가장 하류쪽에 위치하는데, 분지 내에는 고도를 달리하는 여러 단의 하안단구가 분포한다. 즉, 화계분지에서는 과거 여러 번에 걸친 유로변경과 이로 인해 곡류절단이 이루어졌다. 이는 변성암으로 이루어진 홍천강 하류의 좁고 깊은 하곡이 국지적인 침식기준면으로 작용하여 중류에서 하류로의 곡류대 이동이 방해받았기 때문이다. 하안단구의 형성시기는 기존의 연구결과와 비교할 때, 저위 I면과 저위II면이 각각 Early Wurm 빙기와 Late Wurm에 대비되는 marine oxygen isotope stage 4와 2 시기에, 중위면은 Late Riss에 해당하는 marine oxygen isotope stage 6에 형성된 것으로 추정된다.

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A Study on the Efficient Utilization of Farm Tractor and Power Tiller on the Inclined Upland (야산개발농지의 기계화 작업효율 증진에 관한 연구)

  • 최규홍
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.15 no.1
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    • pp.2925-2933
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    • 1973
  • For the efficient utilization of farm machines on the inclined uqland, work performance in plowing, harrowing and terracing and critical workable gradients were tested on three farm machines which are 47 ps-farm tractor, 8 ps-power tiller and 5 ps-power tiller. The results of this study are summarized as follows; 1) The steeper the slope of the upland was the more inefficient the work performance of all machines was. 2) The critical workable gradients of the machines were proved as 14 for 47 ps-farm tractor, 12 for 8 ps-power tiller and 10 for 5ps-power tiller. 3) Plowing in the way of turning the furrow slices against the slope in order to build up terraces, the critical workable gradients were 8 for 47 ps-farm tractor and 8 ps-power tiller and 6 for 5 ps-power tiller. 4) Two-way plow is recommended for plowing with farm tractor on inclined upland, and high lug of tire would be good to prevent the slippage, and side valance-weight should be attached to power tiller for preventing its overturning.

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Properties of Hydrologic Cycle in Catchments in Different Land Use and Runoff Analysis by a Lumped Parametric Model

  • Keiji Takase
    • Proceedings of the Korea Water Resources Association Conference
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    • 2000.05a
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    • pp.48-56
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    • 2000
  • In this paper, properties of hydrologic cycle in three experimental catchments were compared and different types of a lumped parametric model were applied to understand the hydrologic cycle in the catchments. One of them is a forest catchment and another one includes the reclaimed upland fields and last one does terraces paddy fields. The comparison of hydrologic properties showed that the differences in land use have great influences on the soil properties of surface layer, which changes in hydrologic processes such as evapotranspiration and storm runoff et. al. By the runoff analysis models, good agreements between observed and calculated discharge from the catchments were obtained and it was found that the differences in values of optimized model parameters and water budget components reflect those in the hydrologic cycle among them.

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Ministry of Taxation Tower in Baku, Azerbaijan: Turning Away from Prescriptive Limitations

  • Choi, Hi Sun;Ihtiyar, Onur;Sundholm, Nickolaus
    • International Journal of High-Rise Buildings
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    • v.9 no.4
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    • pp.377-386
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    • 2020
  • Beginning a few decades ago, Baku, the capital city of Azerbaijan, has experienced a dramatic construction boom that is revitalizing its skyline. The expansive growth looks to uphold the historic past of Baku as a focal point within the Caspian Sea Region while also evoking aspirations for a city of the future. With superstructure complete and interiors progressing, the Ministry of Taxation (MOT) tower is the latest addition to the city, with its stacked cubes twisting above a multi-level podium at the base. Each cube is separated by column-free green roof terraces, creating unique parametric reveals of the developing surroundings. Aside from MOT's stunning shape, its geolocation resulted in unusually high wind loads coupled with high seismic hazards for a tower of its height. In addition, limitations on possible structural systems required stepping away from a typical prescriptive code-based approach into one that utilized Performance-Based Design (PBD) methods. This paper presents the numerous structural challenges and innovations that allowed the design of a new icon to be realized.

Redox Characteristic and Evolution of a Fragipan of Gangreung Series Commonly Developed in Coastal Terraces (해성단구지에서 발달된 강릉통의 이쇄경반층(Btx) 토양의 산화.환원적 특성에 관한 연구)

  • Zhang, Yong-Seon;Moon, Yong-Hee;Sonn, Yeon-Kyu;Hyun, Byung-Keun;Park, Chan-Won;Yoon, Sung-Won
    • Economic and Environmental Geology
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    • v.45 no.2
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    • pp.137-144
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    • 2012
  • Soil pan typically presents the problems in soil water movement or in aeration which is not appropriate for a plant root growth, In this study physico-chemical characteristics of soils and micromorphological characteristic of clay accumulated zone were investigated to identify redox characteristic and evolution of a fragipan of Gangreung series commonly developed in coastal terraces. Gangreung series is classified as Aquic Fragiudalfs according to the USDA soil taxonomy. It is known that sedimentary ocean floor results in soil pan having parallel liner soil structure due to landscape evolution around 200 to 250 million years ago. it is considered that illite, kaolinite, and vermiculite are major clay minerals contained in a fragipan of Gangreung series. Mixed gray and reddish brown colored band around soil pores was found and would be the redoxmorphic features of fragipan. It is possibly due to accumulated illuvial clay and ferriargillans in soil pores and aggregates in reducing conditions eluding ferrous material. Therefore, mixed colored band around pores in soils of Gangreung series would be developed from the eluted ferrous materials which were accumulated in fragipan during the emerged land formation.

Geomorphic Processes of the Terraces at Lower Reach of Yeongpyeong River in Chugaryeong Rift Valley, Central Korea (추가령 열곡 영평천 하류 단구지형의 형성과정)

  • Lee, Min-Boo;Lee, Gwang-Ryul;Kim, Nam-Shin
    • Journal of the Korean Geographical Society
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    • v.40 no.6 s.111
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    • pp.716-729
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    • 2005
  • In the Yeongpyeong River, one of the branches of Hantan River, there 4 fluvial terraces are identified. During the Quaternary, lava flow from Hantan River had gone 4.5km into upstream Part of the Yeongpyeong River and damed its entrance, and resultantly its lower basin had become a lava-damed paleolake. This study deals with fluvial terrace surface classification, stratigraphic analysis, deposits analysis, and OSL age dating in from Gungpyeongri to Seongdongri in lower reach of Yeongpyeong River, in order to identify Seomorphological Process of the terrace landforms relating to duration of lava-damed paleolake. Terrace surface T4, named Baekeuiri Formation, has been located under Jeongok lava layer to indicate pre-lava river bed. Terrace surfaces T3 and T2 are supposed to be formed during paleolake time, based on $3{\~}4m$ thick sand deposits including pebble and cobble layers, and clay and silt layers intersected with sand ones in nearly horizontal bedding. Terrace T1 is estimated to be formed as post-lake fluvial terrace after dissection of lava dam, based on the more fresh phase of deposits and very low height from present riverbed. The results of the OSL age dating for the T3 deposit layers indicate approximately $33{\~}40ka$, and still lake phase at that time.

Prospect Behavior in the Analysis of Kyumjae Chung Sun's One Hundred Scenes from the Real Landscape Painting (겸재 정선의 진경산수화에 나타난 조망행동 - 진경산수화 100엽을 대상으로 -)

  • 강영조;배미경
    • Journal of the Korean Institute of Landscape Architecture
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    • v.30 no.5
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    • pp.1-15
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    • 2002
  • The purpose of this study is to consider the relationship between point of view and prospect behavior occurring in the experience of a painted landscape. This study analyzes one hundred scenes from the 'real landscape painting' by Kyumjae, one of the most famous landscape painters in 18th century Korea. The results of the study are as follows: 1. It clarified that Kyumjae's real landscape painting's 100 scenes have many view points such as roads, bridges, pavilions, mansions, towers, terraces, hillsides, bases of mountains, broad flat roots, brooksides, and ferries that are apt to occur in the experience of a landscape. The spatial characteristics of view points are expanded fields of vision, evening and night scenes, edges of landforms and structures from which to improve ones vantage point. 2. It showed that 99 out of real landscape painting's 100 scenes depict a view point'to look'and 79 of 'to look through', 73 of 'look around'and 24 of 'to look over'. 3. It showed that real landscape painting's 100 scenes depict that the view point 'to look' is mainly upon a road from which people are looking over an elevated landscape such as the top of a mountain or rockwall. The view behaviors of looking down are depict 15 pavilions, 14 mansions, 2 broad rocks and 10 mountain tops on which people experience landscapes such as fields, rural communities and streams. The view behaviors to look depict 33 ships, 24 roads, 24 pavilions, 19 mansions and 12 terraces on which people experience landscapes such as distant views of mountains, rivers and landscapes. The view behaviors to look around to obtain orientation of landscape are depict 16 pavilions, 10 mountaintops. To glimpse on the way of journey depict 33 ships and 29 roads. To look over depict 11 mansions and 6 pavilions on which experience borrows the landscape. To look through landscapes such as rivers, mountains and rockwalls depict 15 roads, 14 pavilions and 11 mansions. To exchange looks depict 30 ships, 14 roads, 12 pavilions and 12 mansions. We expect that these results might give clues toward the experience of landscapes and the practice of landscape design methods which select viewpoints, and in the design of view points suitable to prospect behaviors.

Estimation of Uplift Rate Based on Morphostratigraphy and Chronology of Coastal Terraces in the SE Part of Korean Peninsula (한반도 남동부에 분포하는 해안단구의 지형층서 및 연대자료를 이용한 융기율 평가)

  • Kim, Ju-Yong;Yang, Dong-Yoon;Choi, Won-Hak;Kim, Jeong-Chan
    • The Korean Journal of Quaternary Research
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    • v.20 no.2
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    • pp.51-57
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    • 2006
  • Terrace stratigraphy of the southeastern coastal areas of Korea is reappraised on the basis of terrace mapping and geochronology. Coastal terraces are divided into uHT ($90{\sim}130\;m$), HT ($63{\sim}86m$), MT ($36{\sim}55\;m$), and LT ($8{\sim}25\;m$) according to altitude. Among these, the Lower Terrace I is interpreted to have formed during MIS 5e based on Tephras Aso-4 (MIS 5c), Ata(MIS 5d or 5e) and OSL data. The age of Lower Terrace II is thought to be MIS 5a based on tephras and OSL data. The uplift rate in the SE part of Korea during the formation of the Lower Terrace (i.e. the MIS 5) ranges from 0.08 to 0.25 mm/yr and averages as 0.15 mm/yr. Such value is quite small in comparison to that of Japan, Taiwan or many other tectonically active areas in the world.

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Soil and Vegetation Characteristics of Abandoned Paddy Field (묵논 습지의 토양 및 식생 특성)

  • Yun, Kwang-Sung
    • Journal of the Korean association of regional geographers
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    • v.13 no.2
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    • pp.129-142
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    • 2007
  • The Purpose of this study is to evaluate the value of abandoned paddy fields as wetland ecosystems and their suitability as habitats for various species. Physical and chemical characteristics of soils and the change of vegetation in paddy fields were analysed -with the passage of time after cease of cultivation. The results of analyses for soil characteristics, vegetation succession, and functional values of abandoned paddy fields as wetlands were as follows: First, top soils become coarser as years after abandonment increase. Second, as the years of abandonment passed. there were significant differences in organic matter, available phosphorate and calcium, while not in magnesium and cation exchange capacity(CEC). Third, species increased from early stage till middle stage, and decreased in late stage. In similarity analysis of species composition, sites were classified into three groups according to the stage of succession. Upper and lower terraces at Daetgol were classified as early stage of succession. The 1st, 2nd and 3rd terraces at Nonbanggol were in middle stage, while tile 4th and 5th were in late stage. Forth, according to evaluation sheets of MoE and RAM(Rapid Assessment Method) standards, me overall average of functional value of Nonbanggol site were 2.13, classified as "common".

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