• Title/Summary/Keyword: hill

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Numerical Study of Stably Stratified Flow over a Three­dimensional Hill in a Channel (성층화된 수로에서 3차원 Hill에 의한 유속장 변동)

  • 박성은;김동선;이충일;황재동;윤종휘;조규대
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.9 no.2
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    • pp.73-77
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    • 2003
  • This study focuses on illustrating the effect of a hill on current filed at a channel, and the topographic effects of the hill were studied with various numerical experiments. The model experiments showed that stratification as well as bottom topography had influence on current fields around the hill. Due to stratification effect, Karman vortex formed behind the hill by bottom topography made effects on water movement only in the deep layer. The vortex reduced density field around the hill which resulted in the stratification in the water column, and which also resulted in the movement of isopycnic surface to deep layer both in front and back of the hill. The water in the back of the hill moved upward along ispycnic surface afterward. From these effects, velocity pattern in vertical direction around the hill showed opposite direction, downwrad in front of the hill and upward in the back. However, the upward flows did not seem to have any significant influence on the water conditions in the surface layer, even though strong upward flows were found on both side of the hill.

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Double Hill-Sachs Lesion in a Recurrent Anterior Shoulder Dislocation Patient -A Case Report - (견관절 전방 재발성 탈구 환자에서 발생한 이중 Hill-Sachs 병변 - 증례 보고 -)

  • Kim, Yong-Min;Park, Kyoung-Jin;Kim, Dong-Soo;Choi, Eui-Sung;Shon, Hyun-Chul;Cho, Byung-Ki;Hong, Kyung-Ho
    • Journal of the Korean Arthroscopy Society
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    • v.15 no.2
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    • pp.121-124
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    • 2011
  • Hill-Sachs lesion is the most common lesion in shoulder dislocation patient and it represented by postero-lateral bony defect of humerus. The lesion could be found in patients who dislocate shoulder joint first time, and it is reported that Hill-Sachs lesion proportionally increases as dislocation does. The location and presence of Hill-Sachs lesion play significant roles in shoulder instability. Authors experienced a double Hill-Sachs lesion in a recurrent anterior shoulder dislocation patient, and thereby report the case with a review of the literature.

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Development of Hill Housing Addatable to the Topographic Characteristics on Sloping Sites (경사지의 지형특성에 적합한 경사지주택 개발 계획)

  • Hyun, Taek-Soo
    • Journal of the Korean Institute of Rural Architecture
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    • v.14 no.1
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    • pp.57-66
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    • 2012
  • This study focuses on the applicability of hill housing design in accordance with topographic characteristics on sloping sites. The urgency for housing still exists but hill sites have to be planned by gradual development using 'all available land' within any particular community. However, there is a reaction towards being more closely involved with nature and landscape. Sloping and hill sites must be developed by intelligent and sensitive planning, integrating the existing environmental factors. The results of this study are as follows : 1. The conditions of location are regarded as the concepts of spactial configuration. It should be developed on the basis of awareness that nature and human beings exist together. 2. It is inevitable that the development of the hill housing should be performed prefer to the topographic characteristics. 3. Planning elements of ecological residental blocks which are possible for constructing on the hill site can be developed and applied, on the basis of geographical characteristics, by housing types.

Hill-Sachs 병변을 동반한 재발된 외상성 견관절 불안정성에서 'Remplissage' 술기를 이용한 관절경적 술식 - 증례 보고 -

  • Go, Sang-Hun
    • The Academic Congress of Korean Shoulder and Elbow Society
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    • 2009.03a
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    • pp.185-185
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    • 2009
  • 관절와 및 상완골의 의미 있는 골결손을 동반한 불안정한 견관절에 대해 어떻게 최선의 치료를 할 것인가에 대한 의문은 남아있다. 어떤 저자들은 외회전과 외전을 제한하는 것으로 Hill-Sachs 병변의 진입을 예방하는 일종의 관혈적 관절낭 변위를 통한 제한된 상완와관절 운동을 주장해왔으며, 다른 관혈적 시술들은 극하근건과 관절낭을 Hill-Sachs 병변 내로 관혈적 전이시키는 것으로 기술되어왔다. 최근에는 여러 저자들에 의해 Hill-Sachs 병변의 진입을 치료하는 더 새로운 접근법들이 기술되었으며, Bankart 병변 복원술에 더하여 Hill-Sachs 병변을 채우기 위해 관절경 하 후방 관절낭 고정술과 극하근건 고정술로 이루어진 이른바 'Remplissage'술기가 소개된 바 있어, 이에 저자는 외상성 견관절 불안정성으로 관절경 하 Bankart 병변 복원술 및 관절낭 축화술 시행 후 외상으로 재발된 견관절 불안정성이 발생하여 관절경 하 Bankart 병변 복원술과 함께'Remplissage'술기를 이용한 Hill-Sachs 병변 복원술을 시행한 예를 보고하는 바이다.

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Review in Remplissage on Anterior Shoulder Instability with Huge Hill-Sachs Lesion (전방 견관절 불안정성의 Hill-Sachs 병변의 치료에서 Remplissage의 Review)

  • Ko, Sang-Hun;Lee, Chae-Chil;Park, Han-Chang
    • Clinics in Shoulder and Elbow
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    • v.14 no.1
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    • pp.134-139
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    • 2011
  • Purpose: We wanted to review the arthroscopic Remplissage technique and introduce our experiences with it for treating recurrent shoulder instability with a large Hill-Sachs lesion. Materials and Methods: The arthroscopic Remplissage technique with Bankart repair is performed in patients with no osteoarthritis, no fracture around the shoulder, a history of recurrence more than 10 times, a large Hill-Sachs lesion more than 30 to 40% of the humeral articular surface and glenoid bone loss less than 20%. Results and Conclusion: For recurrent shoulder instability with a large Hill-Sachs lesion, the Remplissage technique resulted in a good outcome for the shoulder stability, and good clinical and functional results.

Interobserver agreement for detecting Hill-Sachs lesions on magnetic resonance imaging

  • Alkaduhimi, Hassanin;Saarig, Aimane;Amajjar, Ihsan;van der Linde, Just A.;van Wier, Marieke F.;Willigenburg, Nienke W.;van den Bekerom, Michel P.J.
    • Clinics in Shoulder and Elbow
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    • v.24 no.2
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    • pp.98-105
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    • 2021
  • Background: Our aim is to determine the interobserver reliability for surgeons to detect Hill-Sachs lesions on magnetic resonance imaging (MRI), the certainty of judgement, and the effects of surgeon characteristics on agreement. Methods: Twenty-nine patients with Hill-Sachs lesions or other lesions with a similar appearance on MRIs were presented to 20 surgeons without any patient characteristics. The surgeons answered questions on the presence of Hill-Sachs lesions and the certainty of diagnosis. Interobserver agreement was assessed using the Fleiss' kappa (κ) and percentage of agreement. Agreement between surgeons was compared using a technique similar to the pairwise t-test for means, based on large-sample linear approximation of Fleiss' kappa, with Bonferroni correction. Results: The agreement between surgeons in detecting Hill-Sachs lesions on MRI was fair (69% agreement; κ, 0.304; p<0.001). In 84% of the cases, surgeons were certain or highly certain about the presence of a Hill-Sachs lesion. Conclusions: Although surgeons reported high levels of certainty for their ability to detect Hill-Sachs lesions, there was only a fair amount of agreement between surgeons in detecting Hill-Sachs lesions on MRI. This indicates that clear criteria for defining Hill-Sachs lesions are lacking, which hampers accurate diagnosis and can compromise treatment.

CFD evaluation of a suitable site for a wind turbine on a trapezoid shaped hill

  • Unchai, Thitipong;Janyalertadun, Adun
    • Wind and Structures
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    • v.19 no.1
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    • pp.75-88
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    • 2014
  • The computational fluid dynamic is used to explore new aspects of the hill flow. This analysis focuses on flow dependency and the comparison of results from measurements and simulations to show an optimization turbulent model and the possibility of replacing measurements with simulations. The first half of the paper investigates a suitable turbulence model for determining a suitable site for a wind turbine. Results of the standard k-${\varepsilon}$ model are compared precisely with the measurements taken in front of the hilltop, The Reynolds Stress Model showed exact results after 1.0 times of hill steepness but the standard k-${\varepsilon}$ model and standard k-${\omega}$ model showed greater underestimation. In addition, velocity flow over Pha Taem hill topography and the reference geometry shape were compared to find a suitable site for a turbine in case the actual hill structure was associated with the trapezoid geometric shape. Further study of geometry shaped hills and suitable sites for wind turbines will be reported elsewhere.

The Studying on Drum-type Hill-drop Unit

  • Zhang, Xuejun;Yang, Yin
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1996.06c
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    • pp.996-998
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    • 1996
  • The drum-type hill-drop unit, an important working device of the plastic -film-covered hill planter, can finish filling and separating seed precisely, perforating film and holing , and its seeding depth and spacing are stability . The unit is applied to hole seed many crops, for example, cotton, corn , soybean, etc. The drum-type hill-drop unit(DHU) , the key work unit to the plastic film-covered planter, mainly consists of distributor box , seeding parts, hole forming unit and drum , It can be operated to accomplish seeds distributing, hole forming , plastic film perforating . Moreover , its inner cavity can be used as seed box.

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Estimation of Car Insurance Loss Ratio Using the Peaks over Threshold Method (POT방법론을 이용한 자동차보험 손해율 추정)

  • Kim, S.Y.;Song, J.
    • The Korean Journal of Applied Statistics
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    • v.25 no.1
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    • pp.101-114
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    • 2012
  • In car insurance, the loss ratio is the ratio of total losses paid out in claims divided by the total earned premiums. In order to minimize the loss to the insurance company, estimating extreme quantiles of loss ratio distribution is necessary because the loss ratio has essential prot and loss information. Like other types of insurance related datasets, the distribution of the loss ratio has heavy-tailed distribution. The Peaks over Threshold(POT) and the Hill estimator are commonly used to estimate extreme quantiles for heavy-tailed distribution. This article compares and analyzes the performances of various kinds of parameter estimating methods by using a simulation and the real loss ratio of car insurance data. In addition, we estimate extreme quantiles using the Hill estimator. As a result, the simulation and the loss ratio data applications demonstrate that the POT method estimates quantiles more accurately than the Hill estimation method in most cases. Moreover, MLE, Zhang, NLS-2 methods show the best performances among the methods of the GPD parameters estimation.

Environmental Factors Influencing Tree Species Regeneration in Different Forest Stands Growing on a Limestone Hill in Phrae Province, Northern Thailand

  • Asanok, Lamthai;Marod, Dokrak
    • Journal of Forest and Environmental Science
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    • v.32 no.3
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    • pp.237-252
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    • 2016
  • Improved knowledge of the environmental factors affecting the natural regeneration of tree species in limestone forest is urgently required for species conservation. We examined the environmental factors and tree species characteristics that are important for colonization in diverse forest stands growing on a limestone hill in northern Thailand. Our analysis estimated the relative influence of forest structure and environmental factors on the regeneration traits of tree species. We established sixty-four $100-m^2$ plots in four forest stands on the limestone hill. We determined the species composition of canopy trees, regenerating seedlings, and saplings in relation to the physical environment. The relationships between environmental variables and tree species abundance were assessed by canonical correspondence analysis (CCA), and we used generalized linear mixed models to examine data on seedling/sapling abundances. The CCA ordination indicated that the abundance of tree species within the mixed deciduous forest was closely related to soil depth. The abundances of tree species growing within the sink-hole and hill-slope stands were positively related to the extent of rocky outcropping; light and soil moisture positively influenced the abundance of tree species in the hill-cliff stand. Physical factors had a greater effect on tree regeneration than did factors related to forest structure. Tree species, such as Ficus macleilandii, Dracaena cochinchinensis, and Phyllanthus mirabilis within the hill-cliff or sink-hole stand, colonized well on large rocky outcroppings that were well illuminated and had soft soils. These species regenerated well under conditions prevailing on the limestone hill. The colonization of several species in other stands was negatively influenced by environmental conditions at these sites. We found that natural regeneration of tree species on the limestone hill was difficult because of the prevailing combination of physical and biological factors. The influence of these factors was species dependent, and the magnitude of effects varied across forest stands.