• Title/Summary/Keyword: Valley shape

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The Distribution and Geomorphic Changes of Natural Lakes in East Coast Korea (한반도 동해안의 자연호 분포와 지형 환경 변화)

  • Lee, Min-Boo;Kim, Nam-Shin;Lee, Gwang-Ryul
    • Journal of the Korean association of regional geographers
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    • v.12 no.4
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    • pp.449-460
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    • 2006
  • This study aims to analyze distribution of natural lakes including lagoonal lake(lagoon) and tributary dammed lake(tributary lake) and calculate the size, morphology in order to interpret time-serial change of lakes using methodology of remote sensing images(1990s), GIS and topographic maps(1920s) in east coast of Korean Peninsular. Analysis results show that in 1990s, there are 57 natural lakes, with the total size of $75.62km^2$ over size $0.01km^2$. marine-origin lagoons are 48 with total size of $64.85km^2$, composing 85% of total natural lake, and the largest lagoon is Beonpo in Raseon City. Tributary lakes have been formed by damming of tributary channels by fluvial sand bars from main stream, located nearby at coastal zone, similar to lagoon sites. Large tributary lake, Jangyeonho, is developed in lava plateau dissection valley of Eorang Gun, Hamnam Province. There are more distributed at Duman River mouth$\sim$Cheongjin City, Heungnam City$\sim$Hodo Peninsular and Anbyeon Gun$\sim$Gangreung City. Geomorphometrically, correlation of size to circumference is very high, but correlation of size to shape irregularity is very low. The direction of lagoonal coast, NW-SE and NE-SW are predominated due to direction of tectonic structure and longshore currents. The length of the river into lake are generally short, maximum under 15km, and lake size is smaller, degree of size decreasing is higher. Geomorphic patterns of the lake location are classified as coast-hill range, coastal plain, coastal plain-channel valley, coastal plain-hill range and channel valley-hill range. During from 1920s to 1990s, change with lake size decreasing is highest at coastal plain-channel valley, next is coastal plain. Causes of the size decreasing are fluvial deposition from upper rivers and human impacts such as reclamation.

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Finite element analysis of cortical bone strain induced by self-drilling placement of orthodontic microimplant (Self-drilling 방식의 마이크로임플란트 식립에 의해 발생하는 피질골 스트레인의 유한요소해석)

  • Park, Jin-Seo;Yu, Won-Jae;Kyung, Hee-Moon;Kwon, Oh-Won
    • The korean journal of orthodontics
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    • v.39 no.4
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    • pp.203-212
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    • 2009
  • Objective: The aim of this study was to evaluate the strain induced in the cortical bone surrounding an orthodontic microimplant during insertion in a self-drilling manner. Methods: A 3D finite element method was used to simulate the insertion of a microimplant (AbsoAnchor SH1312-7, Dentos Co., Daegu, Korea) into 1 mm thick cortical bone. The shape and dimension of thread groove in the center of the cortical bone produced by the cutting flute at the apical of the microimplant was obtained from animal test using rabbit tibias. A total of 3,600 analysis steps was used to calculate the 10 turns and 5 mm advancement of the microimplant. A series of remesh in the cortical bone was allowed to accommodate the change in the geometry accompanied by the implant insertion. Results: Bone strains of well higher than 4,000 microstrain, the reported upper limit for normal bone remodeling, were observed in the peri-implant bone along the whole length of the microimplant. Level of strains in the vicinity of either the screw tip or the valley part were similar. Conclusions: Bone strains from a microimplant insertion in a self-drilling manner might have a negative impact on the physiological remodeling of cortical bone.

Rearrangement of the Designated Area and Modification of Features of Buryeongsa Valley as a Scenic Site (불영사계곡의 명승 지정구역 조정 및 현상변경 방안 연구)

  • Ahn, Seung-Hong;Hong, Youn-Soon;Kim, Hak-Beom
    • Journal of the Korean Institute of Landscape Architecture
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    • v.37 no.6
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    • pp.48-56
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    • 2010
  • Since ancient times, Korea has been called a land of beauty. Scenic sites under the Cultural Properties Protection Act include picturesque places that are famous for their natural scenic beauty as well as their historical and cultural value. Scenic sites are managed as natural assets to promote their preservation and use. However, the management of scenic sites can produce adverse effects on regional development and ownership rights. Moreover, the purpose of their designation as cultural assets is not fully understood because scenic sites are managed by focusing on restraint on users' act the same as was applied to historic sites. Therefore, the purpose of this study is to protect inhabitants' rights of ownership by arranging the boundaries of designated areas and by providing standard permission for condition changes in the Buryeongsa Valley, which was designated as a Scenic Site in 1979. The results of this study can be summarized as follows: First, arranging the boundaries of the designated area includes the arrangement of the edge lines standardized on the visual range of the mountain ridge, preventing the loss of landscape beauty in the designated district; the internal clearing district focuses on the existing settlement. Gearing the designated areas after the arrangement of the boundaries results in $11,928,932m^2$, 38.6% compared to the existing designated areas. Second, it establishes a 500m buffer zone inside the radius of the boundary of the cultural asset as a standard for condition changes that seriously affect landscape preservation. Third, the standards for permission on building 'height regulations' are divided into flat and gable, according to the roof shape. The adopted standard is 8m high for 2 story flat roofs, and 12m high for 2 story gable roofs.

A Case Study for Simulation of a Debris Flow with DEBRIS-2D at Inje, Korea (DEBRIS-2D를 이용한 인제지역 토석류 산사태 거동모사 사례 연구)

  • Chae, Byung-Gon;Liu, Ko-Fei;Kim, Man-Il
    • The Journal of Engineering Geology
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    • v.20 no.3
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    • pp.231-242
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    • 2010
  • In order to assess applicability of debris flow simulation on natural terrain in Korea, this study introduced the DEBRIS-2D program which had been developed by Liu and Huang (2006). For simulation of large debris flows composed of fine and coarse materials, DEBRIS-2D was developed using the constitutive relation proposed by Julien and Lan (1991). Based on the theory of DEBRIS-2D, this study selected a valley where a large debris flow was occurred on July 16th, 2006 at Deoksanri, Inje county, Korea. The simulation results show that all mass were already flowed into the stream at 10 minutes after starting. In 10minutes, the debris flow reached the first geological turn and an open area, resulting in slow velocity and changing its flow direction. After that, debris flow started accelerating again and it reached the village after 40 minutes. The maximum velocity is rather low between 1 m/sec and 2 m/sec. This is the reason why debris flow took 50 minutes to reach the village. The depth change of debris flow shows enormous effect of the valley shape. The simulated result is very similar to what happened in the field. It means that DEBRIS-2D program can be applied to the geologic and topographic conditions in Korea without large modification of analysis algorithm. However, it is necessary to determine optimal reference values of Korean geologic and topographic properties for more reliable simulation of debris flows.

Coated Tongue Region Extraction using the Fluorescence Response of the Tongue Coating by Ultraviolet Light Source (설태의 자외선 형광 반응을 이용한 설태 영역 추출)

  • Choi, Chang-Yur;Lee, Woo-Beom;Hong, You-Sik;Nam, Dong-Hyun;Lee, Sang-Suk
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.4
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    • pp.181-188
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    • 2012
  • An effective extraction method for extracting a coated tongue is proposed in this paper, which is used as the diagnostic criteria in the tongue diagnosis. Proposed method uses the fluorescence response characteristics of the coated tongue that is occurred by using the ultraviolet light. Specially, this method can solved the previous problems including the issue in the limits of the diagnosis environment and in the objectivity of the diagnosis results. In our method, original tongue image is acquired by using the ultraviolet light, and binarization is performed by thresholding a valley-points in the histogram that corresponds to the color difference of tongue body and tongue coating. Final view image is presented to the oriental doctor, after applying the canny-edge algorithm to the binary image, and edge image is added to the original image. In order to evaluate the performance of the our proposed method, after building a various tongue image, we compared the true region of coated tongue by the oriental doctor's hand with the extracted region by the our method. As a result, the proposed method showed the average 87.87% extraction ratio. The shape of the extracted coated tongue region showed also significantly higher similarity.

Analysis on Fluvial Geomorphological Characteristics based on Past and Present Data for River Restoration: An Application to the Miho River and the Naesung River (하천 복원을 위한 과거 및 현재 자료 기반의 하천지형학적 특성 분석: 미호천과 내성천을 중심으로)

  • Lee, Chan Joo;Kim, Ji Sung;Kim, Kyu Ho;Shin, Hyoung Sub
    • Journal of Korea Water Resources Association
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    • v.48 no.3
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    • pp.169-183
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    • 2015
  • As a basic work for river restoration, analysis on fluvial geomorphological characteristics is made using past and present data to understand close-to-nature geomorphic status. The Miho and the Naesung Rivers are targets of this study. Fluvial geomorphic variables including valley-floor width, sinuosity, bankfull width, channel gradient, bed material size, bankfull discharge and unit stream power are evaluated with dominant processes. Though common sand-bed rivers with similar catchment area, the Miho and the Naesung Rivers are different in terms of valley-floor width, channel shape variables and dominant processes related with longitudinal location. In addition, analyses on interrelationship among the geomorphological variables are carried. Bankfull width is shown to be proportional to bankfull discharge, as is in a rough agreement with the previous studies. Relationship of bankfull discharge and channel gradient shows meandering and braiding are prevalent in the Miho River, whereas the most of the sub-reaches of the Naesung River fall to braiding. Relationship of channel gradient with width-depth ratio indicates dune-ripple processes are dominant in the Miho River, while the Naesung River shows longitudinal diversity from braiding in the downstream sub-reaches to riffle-pool and plane-bed along the upper ones. Analyses based on the past data on a river in a close-to-nature status are thought to be rather reasonable in comparison with those on the same river in a engineered condition.

A Study on the Boulder Stream of Granitoid in Korea (한국 화강암질암류 산지에서 발달하는 암괴류에 관한 연구)

  • Jeon, Young-Gweon
    • Journal of the Korean association of regional geographers
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    • v.6 no.2
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    • pp.71-82
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    • 2000
  • The purpose of this paper is to clarify geomorphic features and development on the boulder stream of granitoid in Korea. Considering the purpose and the method of this paper, three boulder streams are selected : Biseulsan(Mt. Biseul) boulder stream (Daegu city), Maneosan (Mt. Maneo) boulder stream(Gyeongnam province), Geumjeongsan(Mt. Geumjeong) boulder stream (Busan city). The boulder streams mentioned above are bigger in scale and more typical in shape than any other ones in the Korean Peninsula. The main results are summarized as follows. 1. The following are the main features of the boulder streams morphology : the mean gradient is $3{\sim}25^{\circ}$, the longer axes of the component boulders within the deposits averaged about 2m in length, the shapes of the component boulders may be both subangular and subrounded features. 2. The formation of the component boulders is associated with deep weathering of granitoid under warm humid conditions, and the downward movement of boulders occurred by solifluction and frost creep under periglacial conditions. 3. The geomorphic development stage of the boulder streams may be classified into four stages. These boulder streams come under fossil landform stage, the 4th stage ; evidence provided by lichens and weathering features indicate inactive or fossil landform. 4. In generally, boulder streams are well developed on shallow valley floors.

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Geomorphic Features of ${\check{O}}rumkol$(Frozen Valley) Area (Kyungnam Province, South Korea) - Mainly about Talus - (경남 밀양 얼음골 일대의 지형적 특성 -Talus를 중심으로-)

  • Jeon, Young-Gweon
    • Journal of the Korean association of regional geographers
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    • v.3 no.1
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    • pp.165-182
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    • 1997
  • The aim of this paper is to clarify geomorphic features on talus within ${\check{O}}rumkol$ and the origin of ${\check{O}}rumkol$. ${\check{O}}rumkol$ is located in Milyang of Kyungnam province, in South Korea. ${\check{O}}rumkol$ is good area to study talus. because it is characterized by following three geomorphic landscapes : free face surrounding ${\check{O}}rumkol$ ; ${\check{O}}rumkol$ with deep and wide valley floor ; lots of taluses typically developing within ${\check{O}}rumkol$. The main results can be summarized as follows: 1) The origin of ${\check{O}}rumkol$ may be suggested two assumptions : one is that its origin have been resulted from intrusion structure(intrusive rock might capture less resistant rock as tuff) ; the other is that its origin have been resulted from volcanic depression after intrusion or eruption. But these assumptions are not obvious. therefore more geological evidences will be supplemented after this 2) The characteristics of ${\check{O}}rumkol$ talus (1) Pattern ${\check{O}}rumkol$ taluses are tongue-shaped or cone-shaped in appearance. They are $50{\sim}200m$ in length and the range of the maximum width from 25 to 115m and one of their mean slope gradient from 32 to $36^{\circ}$ (2) Origin ${\check{O}}rumkol$ taluses have been formed under periglacial environment in the last glacial age and they are classified into rock fall talus type, considering in conjunction with the shape, hardness, sorting, weathering conditions of constituent debris. (3) The stage of landform development ${\check{O}}rumkol$ talus slope profiles are mainly concave slope. This concave slope type was eventually caused by talus creep at the lower end of the talus. That means new additions of debris from the free face have virtually ceased and there is no evidence of recent motion in the deposit. Now it is predominant that vegetation cover is gradually increasingly. Therefore ${\check{O}}rumkol$ taluses appear to be relict form stage. at present.

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A Study on Settlement Prediction of Concrete-faced Rockfill Dam Using Measured Data During Construction and After Impounding (시공 중 및 담수 후 계측데이터를 이용한 CFRD의 침하량 예측 연구)

  • Lee, Chungwon;Kim, Yongseong
    • Journal of the Korean GEO-environmental Society
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    • v.16 no.2
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    • pp.5-13
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    • 2015
  • In the present study, the prediction methods of the crest settlement after impounding and the maximum internal settlement during dam construction were proposed through the analysis on settlement data at 38 monitored points of 36 Concrete-Faced Rockfill Dams (CFRDs). The results from this analysis provided that the crest settlement and the maximum internal settlement are increased in proportion to the dam height and the void ratio. However, the relationship between internal settlement and dam height for each void-ratio range plotted in semi-logarithmic scale is the nearly same. Also, the prediction of the crest settlement of the CFRD is possible through the maximum internal settlement during dam construction. In addition, it seems that the valley shape highly affects the dense dam body with high construction modulus. The results of this study will provide the useful tool for the design, construction and management of CFRDs.

A Comparative Study on the Architectural Characteristics of Gunjajeong and Gyejeong (군자정(君子亭)과 계정(溪亭)의 건축특성 비교 연구)

  • Jang, Sun-Joo
    • Journal of the Korean housing association
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    • v.25 no.6
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    • pp.57-66
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    • 2014
  • With regard to the pavilion buildings of Imcheonggak Gunjajeong and Donglakdang Gyejeong that are located within residential areas, this study focused on the construction background, the building owner's circumstances and the location environment of these buildings, and attempted to derive the architectural characteristics presented by these two pavilion buildings and, through this, to grasp the architect's intention of plan. The results of this study are as follows. With regard to Gunjajeong, it could be confirmed that, first, it is located in a propitious site and took the composition that follows the family ritual standards for the family rituals of the scholar-gentry class and opens to visitor access, and second, the floor height of the site and interior space was designed so that Munpilbong on the south and the Sarangchae on the west, and the Sadang on the east can be connected visually, and third, the authority and dignity of the head family were built through the symmetric 丁-shaped plane figure, the wide partition module, the form-centered building, and the hierarchical composition of the roof. On the other hand, with regard to Gyejeong, it could be confirmed that, first, it is located along the stream of Jagye valley that has no mountains in the front and in the back and took the composition that put the name symbolizing Taoist thoughts on the surrounding natural environment and was closed to visitor access but opens to nature, and second, with Jagye and Jagye surroundings as the main landscape, it built the concept of intended landscape that symbolizes the Taoist thoughts by giving names not only simply to the visible objects but also to surrounding rocks, and third, the asymmetric ㄱ-shaped plane composed a yard-centered space rather than emphasizing the shape, and connected the part of the plane with Jagye so as to be embodied as a personal inner self-perfecting place that closely communicates only with nature away from the mundane world.