• Title/Summary/Keyword: sinuosity

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Interpretation of Emergence of Urban Civilization by Sinuosity Ratio (都市文明의 發生과 肢節率)

  • 남영우
    • Journal of the Korean Geographical Society
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    • v.35 no.3
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    • pp.427-435
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    • 2000
  • 본 연구는 인문.사회현상도 자연현상과 마찬가지로 수학적 해석이 가능하다는 전제하에 시도된 것이다. 인류의 문명사는 공간상에 전개된 인간행동의 기록이라 할 수 있다. 그러므로 행동과학적 기법을 이용하며 인류문면이 발달한 지리적 메커니즘을 규명할 수 있을 것이다. 연구결과, 도시의 발생은 잉여생산품과 인구규모, 수송가능성등의 지리적 비교 우위로 설명 될 수 있으며, 그것은 $\ulcorner$지절$\lrcorner$이라는 새로운 개념을 적용함으로써 파악될 수 있다는 것이다. $\ulcorner$지절$\lrcorner$은 수평지절과 수직지절로 구분되면, 지절의 정도는 지절률로 측정될 수 있다.

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Lateral Migration Features of the Alluvial Channels in Hapyeong Intake Station, Nakdong River (해평취수장 부근에서 충적하천의 저수로 이동 특성)

  • Jang, Chang-Lae;Lee, Gang-Man;Kim, Gye-Hyun
    • Journal of Korea Water Resources Association
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    • v.41 no.4
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    • pp.395-404
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    • 2008
  • It is important to understand the complex, various migration features of the alluvial channels for river engineering. In this study, the morphological changes and migration features of alluvial channels were investigated by analyzing the aerial photographs of active channels between 1972 and 2004 in Hapyeong Intake Station, Nakdong river. The lower channels were migrated from left bank to right bank and showed the features of braided channel in 2004. The instability of lower channels was increased due to the increased channel slope and width. The sinuosity of lower channels was decreased with time. As time increased, the increasing rate of lower channel and lateral migration rate were decreased. As a result of meso-scale regime analysis by using bankfull discharge, multiple row bars were developed, and suspended sediment load was governed in the flow as a sand bed channel.

Assessment of Channel Stability with Groynes (수제 설치에 의한 하도 안정성 평가)

  • Kim, Gi Jung;Jang, Chang-Lae;Lee, Kyung Su
    • Ecology and Resilient Infrastructure
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    • v.6 no.4
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    • pp.314-327
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    • 2019
  • This study investigates channel stabilities with groynes by developing the assessment of it and applying a 2-dimensional numerical model, which simulates flow and sediment transport with various flows in the channel. Evaluation inventories are composed of five items, which are width to depth ratio, sinuosity, bed slopes, velocities in the flow flied, Shields number with discharges and geomorphic characteristics in the study reach. The channel stability is evaluated by applying the evaluation indicators to the channel with and without groynes in the study reach between Dalseong-weir and Gangjeonggoryeong-weir in the Nakdong river. Width to depth ratio, sinuosity, and bed slopes, which are index of river characteristics, little affect the channel stability. However, velocities in the flow flied, and Shields number, which is dimensionless tractive, near the banks of the channel strongly affect the stability. The evaluation values of the stability in the channel on the left and right banks decrease as the number of groynes increase in both the left and right banks, which means that the bank stability increases with the groynes.

Migration Characteristics in Sine-Wave Type Rivers

  • Cha, Young-Kee;Pai, Dong-Man;Lee, Jong-Seok
    • Korean Journal of Hydrosciences
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    • v.4
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    • pp.81-92
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    • 1993
  • This paper presents a model on the migration characteristics which is developed by using the equations for conservation of mass, momentum, and for lateral stability of the streambed. This model enables prediction of the magnitude the location of near-bank bed scour as well as rates and direction of meander migration in the sine-wave type revers (SWR) of small sinuosity. It is evident from this study that the transverse bed slope factor B' and transverse mass flux factor play significant roles in predicting migration characteristics, and their values of B'=4.0 and $\alpha$= 0.4 seem reasonable. This model will produce a useful quidelines in planning, design, construction, and development of SWR basin projects.

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Analysis of River Disturbance using a GIS(II) (GIS기법을 이용한 하천 교란 실태의 분석(II))

  • Park, Eun-Ji;Kim, Kye-Hyun;Jang, Chang-Lae
    • Journal of Korea Spatial Information System Society
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    • v.10 no.4
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    • pp.27-35
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    • 2008
  • Current re-arrangement of rivers and waterways have been made uniformly ignoring characteristics of individual rivers thereby aggravating artificial river restructuring. On the contrary, quantitative techniques to evaluate the aftermath of artificial river disturbance such as uprising of river bed, intrusion of foreign fisheries, and changes of ecological habitats are not available. To establish such quantitative techniques, analysis of the river changes to evaluate the major causes of the river disturbance and its impacts is essential. Therefore, research for proposing a method which can be applied for the development of techniques to investigate river disturbance according to the major factors for the domestic rivers using airphotos and GIS techniques was preceded. In this study, the study area on the downstream of the river was selected and analysis of river disturbance using preceding method was done to confirm the benefit of analyzing river disturbance using GIS techniques. Trend analysis of the waterway sinuosity and changes of the flow path leaded to detailed verification of the river disturbance for specific location or time period, and this enabled to generate relatively accurate numbers representing sinuosity of the waterway and relevant changes. Also, it is possible to predict the effect on the current re-arrangement of the river and waterway to river flow using the analysis of past river change. It is necessary to establish GIS based proper measures for environmental river restoration using the results from this study and future works.

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The Evaluation of Small Scaled Stream Naturalness for Stream Channel Restoration (소하천 환경조성사업의 평가를 위한 소하천자연도 평가)

  • Ahn, Tae-Jin
    • Journal of Korea Water Resources Association
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    • v.40 no.5
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    • pp.359-369
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    • 2007
  • In this study the evaluation method for riverine naturalness proposed previously by other researcher has been modified to assess stream naturalness of small scaled streams. Two evaluation items have been added to the previously proposed method. That is, the modified method for evaluating naturalness of small scaled streams contains 16 evaluation items with two categories - river morphology and river environments. The three evaluation items have been improved based on the results of stream configuration and characteristics investigation. To prepare evaluation index for channel configuration of small scaled stream, 55 small scaled streams have been selected to analyze sinuosity, wavelength, etc. It has been shown that the values of sinuosity are around 1.2 and one wavelength appears approximately every 500 m in the sample streams. An equation implied diversity for width of normal flow has been proposed to add the evaluation index for diversity of channel width. The every 500 m 1,000 m along small scaled stream is also recommended through the investigation as the interval of evaluation unit. The modified method has been applied to the DangWang stream to estimate the effect of stream rectification project. It has shown that the proposed method would appropriately reflect channel morphology and environments before and after the rectification project.

Morphometrical characteristics of River Meandering (하천 사행의 계량형태학적 특성)

  • 이재우;이원환
    • Water for future
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    • v.14 no.1
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    • pp.39-49
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    • 1981
  • The purpose of this study is to examine the meander charactericstics for the rivers in Korea..In this study, the new characteristics factors of meander are proposed, and the relationships among the factors proposed in this study and the existing factors are derived. An attempt is made to find considerable relation among meander characteristics, but width and meander belt did not show any defined trend and considerable scatter of points was observed. Relationships among the meander length, belt and flowrate, etc., which are factors of meander characteristics, are analyzed the 67 rivers above 30km in length. Channel shape factor which is the ratio of the length from the starting point to the end to the channel lenght, tortuosity which is the ratio of the curved channel length against the channel length are suggested for a new characteristics factor of meander. They are well correlated with channel length, Horton's shape facotr and meander gradient, consequently have to be important measures of river meander. The result of the detailed comparison and the analysis of degree of sinuosity, velocity and water surface slop are brought light on the fact show that the curved reach is morestable than the straight one. The ratio of the meander length to the meander belt and its accumulative frequency showed excellent correlationship when plotted on the semi-log paper. The results of regression analysis of meander belt and meander length show linear for the South Han river branches and power curve for the Geum river and the Nakdong river branches.

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Effect of the STereoLithography File Structure on the Ear Shell Production for Hearing Aids According to DICOM Images (DICOM 영상에 의한 STL 파일 구조가 보청기 이어 쉘 제작에 미치는 영향)

  • Kim, Hyeong-Gyun
    • Journal of radiological science and technology
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    • v.40 no.1
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    • pp.121-126
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    • 2017
  • A technique for producing the ear shell for a hearing aid using DICOM (Digital Imaging and Communication in Medicine) image and a 3D printing was studied. It is a new application method, and is an application technique that can improve the safety and infection of hearing aid users and can reduce the production time and process stages. In this study, the effects on the shape surface were examined before and after the printing of the ear shell using a 3D printer based on the values obtained from the raw data of the DICOM images at the volumes of 0.5 mm, 1.0 mm, and 2.0 mm, respectively. Before the printing, relative relationship was compared with respect to the STL (STereoLithography) file structure; and after the printing, the intervals of the layered structure of the ear shell shape surface were compared by magnifying them using a microscope. For the STL file structure, the numbers of triangular vertices, more than five intersecting points, and maximum intersecting points were large in the order of 0.5 mm, 1.0 mm, and 2.0 mm, respectively; and the triangular structure was densely distributed in the order of the bending, angle, and crest regions depending on the sinuosity of the external auditory meatus shape. As for the ear shell shape surface examined by the digital microscope, the interval of the layered structure was thick in the order of 2.0 mm, 1.0 mm, and 0.5 mm. For the STL surface structure mentioned above, the intersecting STL triangular structure was denser as the sinuosity of the 3D ear shell shape became more irregular and the volume of the raw data decreased.

Change characteristic of basin topographical parameters according to the threshold area of minimum order stream (최소차 하천의 임계면적에 따른 유역 지형매개변수의 변화특성)

  • Ahn Seung-Seop;Park Ro-Sam;Kim Jong-Ho;Lim Ki-Seok;Song Si-Hoon
    • Journal of Environmental Science International
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    • v.14 no.1
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    • pp.33-40
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    • 2005
  • The size of minimum order stream has a very sensitive effect on runoff analysis model using the divergence characteristic of stream. Therefore, in this study, the threshold area of minimum order stream has been examined the change characteristic of topographical parameters. The subject basin of the research was the upper basin of the Kumho water gage station which is located in the middle of the Kumho river. The 1:25,000 numerical geography which was constructed $10{\times}10m$ mesh was used. The range of investigation of topographical parameters are number of stream order, length, area, slope, basin relief, sinuosity ratio, drainage density and total stream length etc. It was found from the result of analysis that the threshold value of minimum order stream has a very big effect on topographical parameters of basin. It was found that the threshold area of minimum ord er stream revealed under $0.10km^{2}.$ Furthermore, the parameters showed a serious change except for over $0.10km^{2}.$

“Art Nouveau양식(樣式)이 현대의상(現代衣裳)에 미친 영향”

  • Jeong, Heung-Suk
    • Journal of the Korean Society of Costume
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    • v.4
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    • pp.25-37
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    • 1981
  • Art Nouveau style refers to the movement of art which was started in France and Belgium in the last decade of the 19th and the early years of the 20th century. The distinguishing characteristics of Art Nouveau style are the sensous sinuosity of its line, nervously undulating, curving over itself, rhythmical, flowing in endless patterns, which are inspired by animals and plants, specially by flowers, leaves, long stalks. The Art Nouveau style includes also the extreme simplicity of form, and asymmetric design. This new trend of art movement spread into architecture, furniture, wall papers, graphic design, accessories and textiles. In this paper, I tried to find out whether or not the Art Nouveau style had an effect on clothing. Because I believe clothing, like architecture, painting, and sculpture, is an Art form that derives from a particular set of cultural circumstances and reflects the needs and aspirations of the society for which it is created. Fashions in clothing over the last five thousand years have mirrorred the art form as well as the spirit. The result of this study shows that the Art Nouveau style made a lasting contribution to the modernism of clothing as well as architecture and interior design at the end of 19th century and the early years of the 20th century. The modernism of clothing appeared in the straight silhouette, asymmetric design, simple and light trimming, embroidery with Art Nouveau pattern, and stylized flower design in textile. Art Nouveau made a great contribution toward the modern clothing to have its liveliness and its harmonious relationship between clothing design and the use of materials.

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