• Title/Summary/Keyword: TOPOGRAPHICAL CONDITION

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Numerical Simulations of Rip Currents Under Phase-Resolved Directional Random Wave Conditions (위상을 포함한 다방향 불규칙파 조건에서의 이안류 수치모의)

  • Choi, Junwoo
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.27 no.4
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    • pp.238-245
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    • 2015
  • Recently, Choi et al.(2015) showed that a numerical simulation of the SandyDuck experiment under a directional random wave environment agreed well with the experimental data including the wave height distribution of the random waves, the well-developed longshore current and its energetic fluctuation. Based on the Boussinesq modeling, this study investigates the effect of the alongshore variations, which are induced by not only the field topography but also the phase interaction of multidirectional random waves in the surf zone wave field, on the rip currents. As a result, transient rip currents as well as topographical rip currents cause the complicated surfzone circulation and mixing process due to their interactions in a multi-directional random wave condition while the topographical rip currents are dominant in a monochromatic wave condition.

Comparison of Flooding Area Estimation using GIS and Hydraulic Model (GIS와 수리모형을 이용한 홍수지역예측 비교)

  • Kim, Seok-Gyu;Song, In-Ho;Kim, Chul
    • Journal of the Korean Association of Geographic Information Studies
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    • v.9 no.3
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    • pp.183-192
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    • 2006
  • In recent years, the damage caused by flood has been gradually increased. The cause of the flood is unusual weather condition as well as topographical and geographical condition of our country. Flood area analyzing vulnerable flood areas on large regions without previous flood records were developed using GIS and hydraulic model, flood depth by return periods and topographical data such as DEM. The study area is the Munsan river basin. The results using GIS comparing the results using hydraulic model. The results in this study can be used to delineate the potential flooding areas in large regions and the damage from disasters can be reduced by making provisions with the obtained results.

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Ex-situ Stabilization and Utility Prospects of 'Jata' Ecorace of Tropical Tasar Silkworm Antheraea mylitta Drury

  • Hansda, G.;Reddy, R. Manohar;Sinha, M. K.;Ojha, N. G.;Prakash, N. B. Vijaya
    • International Journal of Industrial Entomology and Biomaterials
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    • v.17 no.2
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    • pp.169-172
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    • 2008
  • Indian tropical tasar silkworm, Antheraea mylitta D is reported to have forty four ecoraces by way of their adoption to different topographical and vegetational conditions. Of late, another ecorace 'JATA' - univoltine under in-situ condition has been explored which is localized in Thakurmunda area of the foot hills of Simlipal biosphere (Mayurbhanj district) of Orissa, India. The ecorace 'Jata' exhibits superior economic characters over widely commercialized ecoraces of Daba and Sukinda. The cocoon production of localized 'Jata' ecorace is depleting day by day in in-situ condition. In the present study, efforts were made to stabilize the ecorace 'Jata' under ex-situ condition at Ranchi (Jharkhand), where the 'Jata' ecorace silkworms were reared on Terminalia tomentosa for four successive generations during 2006 and 2007 and the cocoons were preserved in grainage house under prevailing climatic conditions. The results indicated change in voltinism behaviour of the 'Jata' ecorace from univoltine to bivoltine. The rearing performance and grainage efficiencies indicate the tendency of 'Jata' ecorace towards acclimatization and stabilization under Ranchi climatic conditions. The 'Jata' ecorace manifests the prospects for acclimatization, stabilization and commercial exploitation.

Fascicular Involvement of the Median Nerve Trunk in the Upper Arm: Manifestation as Anterior Interosseous Nerve Syndrome With Unique Imaging Features

  • Jae Eun Park;Darryl B. Sneag;Yun Sun Choi;Sung Hoon Oh;SeongJu Choi
    • Korean Journal of Radiology
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    • v.25 no.5
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    • pp.449-458
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    • 2024
  • Selective fascicular involvement of the median nerve trunk above the elbow leading to anterior interosseous nerve (AIN) syndrome is a rare form of peripheral neuropathy. This condition has recently garnered increased attention within the medical community owing to advancements in imaging techniques and a growing number of reported cases. In this article, we explore the topographical anatomy of the median nerve trunk and the clinical features associated with AIN palsy. Our focus extends to unique manifestations captured through MRI and ultrasonography (US) studies, highlighting noteworthy findings, such as nerve fascicle swelling, incomplete constrictions, hourglass-like constrictions, and torsions, particularly in the posterior/posteromedial region of the median nerve. Surgical observations have further enhanced the understanding of this complex neuropathic condition. High-resolution MRI not only reveals denervation changes in the AIN and median nerve territories but also illuminates these alterations without the presence of compressing structures. The pivotal roles of high-resolution MRI and US in diagnosing this condition and guiding the formulation of an optimal treatment strategy are emphasized.

Study on Conversion Permission Standard considering the Topography and Ecological Location of the Mountain Areas (산지 지형 및 생태적 입지를 고려한 산지이용기준 개발에 관한 연구)

  • CHOI, Jung-Sun;KWAK, Doo-Ahn;KWON, Soon-Duck
    • Journal of the Korean Association of Geographic Information Studies
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    • v.22 no.4
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    • pp.59-71
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    • 2019
  • In Mountainous Districts Management Act of Korea Forest Service, slope and elevation criteria are operated to regulate the indiscriminate use of risky land parcels when forestland is converted to other land use types. However, there is a limitation in considering topographical variation with only such two indices in the land parcel. Therefore, in order to supplement insufficient criteria, the slope type standard was developed using Catena, and the ecological condition improved terrain standards. Firstly, the ratio of 'risky slope' in a target forestland parcel was defined to decrease the risk of disasters such as landslides. Secondly, the standard of the ecological location condition was proposed as ecological score by integrating age, diameter and soil depth classes in the target forestland parcels. Thereby, we could prepare reasonable standards that can reduce forestland disasters and ecological damages, as suggesting new topographical and ecological assessment methods for forestland use conversion.

Selection Criteria of Harvesting and Logging Methods in Consideration of Forest Terrain Characteristics (산림지형특성(山林地形特性)을 고려한 산림수확방법(山林收穫方法) 및 집재방법(集材方法)의 선정기준)

  • Kim, Ki Weon
    • Journal of Korean Society of Forest Science
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    • v.82 no.2
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    • pp.195-206
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    • 1993
  • The purpose of this study is to provide a basis for establishing regional harvesting systems that ist the prerequisites for the forest mechanization. The factors restricting to the forest harvesting and logging methods from topographical aspects are studied for this purpose. Three main harvesting methods studied in this paper are : shortwood method, longwood method and full tree method. This study shows : the shortwood method is suitable for low, the longwood method for medium, the full tree method for high topographical conditions. For the logging methods, the focus of the study is on various ground based logging systems by animalpower, manpower, gravitation, wheeled & crawler vehicle and cable. The factors limiting the coverage of logging operation are slope and logging distance. The cable crane logging methods are classified by logging distance into short distance(to 300 or 400m), middle distance(to 700 or 800m) and long distance cable crane methods (over 700 or 800m). The wheeled vehicle method shows serious damages to forest resources, whereas the logging by log-line of the gravitation logging method and cable crane method tend to minimize such damages. The wheeled & crawler vehicle method also shows difficult to apply in the high slope conditions, whereas cable crane method can be applied to maximum 120% steep slope and uphill conditions.

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Distribution of Soil Fertility in Paddy Fields as Affected by Cultivation Methods and Topographical Regions (경작지대 및 재배방법에 따른 논토양의 비옥도 분포)

  • Kim, Dong-Jin;Kang, Da-Seul;Ahn, Byung-Koo;Lee, Jin-Ho
    • Korean Journal of Organic Agriculture
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    • v.23 no.3
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    • pp.595-604
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    • 2015
  • Soil chemical properties in paddy fields were found to be varied depending upon different cultivation methods such as environmentally-friendly, conventional, and two-crop farming systems and different topographical regions, namely plain, middle mountainous, and reclaimed land regions. Overall soil pH was found to be in optimal range (pH 5.5~6.5) for rice cultivation, except with conventional cultivation fields of the reclaimed lands in Jeonnam province. Electrical conductivity (EC) was relatively higher in the two-crop cultivation fields than in others. However, the concentrations of available phosphate as $P_2O_5$ were exceptionally higher in the two-crop farming fields, thus in submerged paddy condition the phosphate could be released into streams and rivers. Soil organic matter (SOM) contents were mostly in optimal range ($25{\sim}30g\;kg^{-1}$) for paddy field in Jeonbuk province, but in Jeonnam province they were slightly higher values of the range. The concentrations of available silicate ($SiO_2$) were mostly depended on the cultivation methods and the region, but some of paddy fields contained extremely high $SiO_2$ concentration. Statistical relationships among the soil chemical properties showed as follows: Correlations between EC values and exchangeable cation concentrations, between SOM contents and CEC values, and between available $SiO_2$ concentrations and pH, EC, exchangeable cations, and CEC values were positively significant, whereas total nitrogen concentrations were significantly negatively correlated with the concentrations of exchangeable K and Mg. These results might be very useful to establish benchmark paddy fields contained with certain levels of soil fertility.

Developing of Forest Fire Occurrence Danger Index Using Fuel and Topographical Characteristics on the Condition of Ignition Point in Korea (산불발화지점의 임상 및 지형특성을 이용한 산불발생위험지수 개발)

  • Lee Si-Young;Won Myoung-Soo;Han Sang-Yoel
    • Fire Science and Engineering
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    • v.19 no.4 s.60
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    • pp.75-79
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    • 2005
  • This study has developed Forest Fire Occurrence Danger Index (FFODI) using fuel and topographical characteristics for the practical purposes of forecasting forest fire occurrence danger rating. This was made on the basis of the 126 forest fire site according to field survey. The result of fire frequency analysis showed 87 sites on conifer $(69\%)$, 21 on mixed $(16.7\%)$ and 18 $(14.3\%)$ on non-conifer. The scale for Fuel Model Index(FMI) ranges from 1 to 10 and Topography Model Index(TMI) from 1 to 5. FMI is 10 on the conifer, 3 on the mixed and 2 on the non-conifer. In case of topographical analysis, it was estimated that 90 site $(71.4\%)$ of ignition point was bottom foot hill and 22 site $(17.5\%)$ was on the southwest. TMI in southwest direction is 5.0, 4.5 in the northwest and the northeast, 4.0 in the southeast and the south, 2.5 in the north and the west and 1.5 in the east. TMI in the bottom foot hill is 5 in the bottom foot hill, 1.5 in the upper foot hill, 1.0 in the bottom middle slope and 0.5 in the upper middle slope and bottom ridge.

Evaluation of Equations for Estimating Pan Evaporation Considering Regional Characteristics (지역특성을 고려한 pan 증발량 산정식 평가)

  • Rim, Chang-Soo;Yoon, Sei Eui;Song, Ju Il
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.1B
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    • pp.47-62
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    • 2009
  • The climate change caused by global warming may affect on the hydro-meteorologic factor such as evaporation (IPCC, 2001). Furthermore, it is also necessary that the effect of climate change according to geographical condition on evaporation should be studied. In this study, considering geographical and topographical conditions, the 6 evaporation equations that have been applied to simulate annual and monthly pan evaporation were compared. 56 climatologic stations were selected and classified, basing on the geographical and topographical characteristics (urbanization, topographical slope, proximity to coast, and area of water body). The evaporation equations currently being used are applied. These evaporation equations are Penman, Kohler-Nordenson-Fox (KNF), DeBruin-Keijman, Priestley-Taylor, Hargreaves, and Rohwer. Furthermore, Penman equation was modified by calibrating the parameters of wind function and was verified using relative error. The study results indicate that the KNF equation compared best with the pan: relative error was 8.72%. Penman equation provided the next-best values for evaporation relative to the pan: relative error was 8.75%. The mass-transfer method (Rohwer) provided the worst comparison showing relative error of 33.47%. In case that there is a close correlation between wind function and wind speed, modified Penman equation provided a better estimate of pan evaporation.

A Analysis on the Accumulation Characteristics of Salt Contaminants for Outdoor Insulators with Statistical Treatment (통계 처리기법을 활용한 옥외 절연물의 염해 오손물 누적특성 분석)

  • Choe, Nam-Ho;Park, Gang-Sik;Han, Sang-Ok
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.51 no.1
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    • pp.39-45
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    • 2002
  • To determine the representative pollution degree of outdoor insulators during the drought season, we should make an investigation on the long-term accumulation characteristics of contaminants. As the contamination mechanism of outdoor insulator is extremely depend on the climatic condition, there is a large difference between the research result of Japanese utilities. So based on the difference of precipitation of the Korea and Japan, we could say that the accumulation characteristics of the countries have a significant difference. But, based on the result of Japan, the accumulation property of contaminants was ignored in KEPCO\`s specification. So, to determine the accumulation characteristics of Korea, we measured the 2 and 3 month ESDD with brush wiping method and make a statistical analysis on measured data. And, from the results, we understood the accumulation characteristics of Korea and the influence of topographical condition on the distribution characteristics of salt contaminants. coast.