• Title/Summary/Keyword: critical inclination

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Numerical analysis of deep excavation in layered and asymmetric ground conditions (흙막이 굴착 시 지층 경사의 영향에 대한 수치해석적 분석)

  • Shin, Jong-Ho;Kim, Hak-Moon;Kim, Sang-Hwan;Kim, Sang-Kil;Nam, Taek-Soo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.1260-1268
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    • 2008
  • In case of deep excavation analysis, the theory of beam on elasto-plastic geo-material (elasto-plastic theory) can not consider the inclined ground layers appropriately. It is frequently assumed that the soil layers are parallel to the surface. However, the soil layers are generally inclined and even asymmetric. The common modelling of the asymmetric half section of the excavation system using the elasto-plastic theory, can lead differences from the real behaviour of ground, which has critical significance in case of deep excavation in urban area. In this study, an attempt to find appropriate modelling methods was made by carrying out a comparative study between the FEM and the elasto-plastic analyses. It is shown that in case of the upward-inclined soil profile the elasto-plastic theory may underestimate the performance of retaining structures.

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Parametric numerical study of wind barrier shelter

  • Telenta, Marijo;Batista, Milan;Biancolini, M.E.;Prebil, Ivan;Duhovnik, Jozef
    • Wind and Structures
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    • v.20 no.1
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    • pp.75-93
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    • 2015
  • This work is focused on a parametric numerical study of the barrier's bar inclination shelter effect in crosswind scenario. The parametric study combines mesh morphing and design of experiments in automated manner. Radial Basis Functions (RBF) method is used for mesh morphing and Ansys Workbench is used as an automation platform. Wind barrier consists of five bars where each bar angle is parameterized. Design points are defined using the design of experiments (DOE) technique to accurately represent the entire design space. Three-dimensional RANS numerical simulation was utilized with commercial software Ansys Fluent 14.5. In addition to the numerical study, experimental measurement of the aerodynamic forces acting on a vehicle is performed in order to define the critical wind disturbance scenario. The wind barrier optimization method combines morphing, an advanced CFD solver, high performance computing, and process automaters. The goal is to present a parametric aerodynamic simulation methodology for the wind barrier shelter that integrates accuracy and an extended design space in an automated manner. In addition, goal driven optimization is conducted for the most influential parameters for the wind barrier shelter.

Existentialist Perspectives to Science Teaching and Teacher Education in the Competency-based Curriculum

  • Kwak, Youngsun
    • Journal of the Korean earth science society
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    • v.34 no.5
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    • pp.428-434
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    • 2013
  • In this commentary, I examined the implications of Existentialism for science teaching and teacher education. Existentialist thoughts and premises can be used to explore the human element in an educational system. Before emphasizing the pragmatic and technical aspects of teaching, we need to rethink why we teach and recognize our learners as unique beings in a continual process of becoming. By incorporating the existential perspective into curriculums and pedagogies of science education, we can help learners to make their existences and experiences meaningful. This paper consists of three parts. In the first part, I drew on relevant aspects of Existentialism and its implications on the views of the learner. In the second part, I examined the competency-based curriculum in light of Existentialism. Existentialism aims, in part, to develop an educated person who possesses a clear sense of personal identity, a critical attitude, and the inclination to be a life-long learner, and so on. These characteristics are consistent with the implications developed from the competency-based curriculum. In the third part, I explored pedagogical activities consistent with existentialist thinking the ultimate goal of which is to create authentic individuals who can take responsibility for being humans. In the conclusion, I discussed how existentialist ways of thinking and teaching call for the science teacher's reflective practices, where the teacher needs to integrate personal and professional knowledge as the situation demands.

Operating condition optimization of liquid metal heat pipe using deep learning based genetic algorithm: Heat transfer performance

  • Ik Jae Jin;Dong Hun Lee;In Cheol Bang
    • Nuclear Engineering and Technology
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    • v.56 no.7
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    • pp.2610-2624
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    • 2024
  • Liquid metal heat pipes play a critical role in various high-temperature applications, with their optimization being pivotal to achieving optimal thermal performance. In this study, a deep learning based genetic algorithm is suggested to optimize the operating conditions of liquid metal heat pipes. The optimization performance was investigated in both single and multi-variable optimization schemes, considering the operating conditions of heat load, inclination angle, and filling ratio. The single-variable optimization indicated reasonable performance for various conditions, reinforcing the potential applicability of the optimization method across a broad spectrum of high-temperature industries. The multi-variable optimization revealed an almost congruent performance level to single-variable optimization, suggesting that the robustness of optimization method is not compromised with additional variables. Furthermore, the generalization performance of the optimization method was investigated by conducting an experimental investigation, proving a similar performance. This study underlines the potential of optimizing the operating condition of heat pipes, with significant consequences in sectors such as high temperature field, thereby offering a pathway to more efficient, cost-effective thermal solutions.

Effects of Nitrogen , Phosphorus and Potassium Application Rates on Oversown Hilly Pasture under Different Levels of Inclination II. Changes on the properties, chemical composition, uptake and recovery of mineral nutrients in mixed grass/clover sward (경사도별 3요소시용 수준이 겉뿌림 산지초지에 미치는 영향 II. 토양특성 , 목초의 무기양분함량 및 3요소 이용율의 변화)

  • 정연규;이종열
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.5 no.3
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    • pp.200-206
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    • 1985
  • This field experiment was undertaken to assess the effects of three levels of inclination ($10^{\circ},\;20^{\circ},\;and\;30^{\circ}$) and four rates of $N-P_2O_5-K_2O$ (0-0-0-, 14-10-10, 28-25-25, and 42-40-40kg/10a) on establishment, yield and quality, and botanical compositions of mixed grass-clover sward. This second part is concerned with the soil chemical properties, concentrations and uptake of mineral nutrients, and percent recovery and efficiency of NPK. The results obtained after a two-year experiment are summarized as follows: 1. The pH, exchangeable Mg and Na, and base saturation in the surface soils were decreased by increasing the grade of inclination, whereas organic matter and available $P_2O_5$ tended to be increased. However, the changes in the Ca content and equivalent ratio of $K\sqrt{Ca+Mg}$ were not significant. The pH, exchangeable Ca and Mg, and base saturation were reduced by increasing the NPK rate, whereas available $P_2O_5$, exchangeable K, and equivalent ratio of $K\sqrt{Ca+Mg}$ tended to be increased. 2. The concentrations of mineral nutrients in grasses and weeds were not significantly affected by increasing the grade of slope in hilly pasture, whereas the concentrations of N, K, and Mg in legume were the lowest with the steep slope, which seemed to be related to the low legume yield. The Mg concentrations of all forage species were below the critical level for good forage growth and likelihood of grass tetany. 3. The increase of NPK rate resulted in the increment of N, K and Na concentrations, and the decrease of Mg and Ca in grasses. The P concentration was increased with P application, but there were no differences in that among the P rates applied. It resulted also in a slight increase of K, and a decrease of Mg in legume, but the contents of N, Ca, and Na were not affected by that. On the other hand, it has not affected the mineral contents in weeds except a somewhat increase of N. The mixed forages showed a increase of N and K contents, a decrease of Ca and Mg, and a slight change in P and Na. 4. The percent recovery of N, P and K by mixed forages were greatly decreased by increasing the grade of inclination and NPK rate. They were high in the order; K>N>P. The efficiency of mixed NPK applications was decreased by that. The efficiency of mixed NPK fertilizers absorbed was slightly decreased by the increased rate of NPK, but it was not affected by the grade of inclination.

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Stability Evaluation Methods of Agricultural Reservoir by Field Monitoring (현장계측에 의한 농업용저수지 제체의 안정관리기법)

  • Lee, Dal-Won;Oh, Beom-Hwan
    • Korean Journal of Agricultural Science
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    • v.30 no.2
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    • pp.164-174
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    • 2003
  • This study was performed to suggest a rational method for the stability evaluation of agricultural reservoir in the very soft ground. The stability methods for agricultural reservoir was used to compare and analyze with various condition by limit equilibrium method. The behavior of settlement-displacement obtained by field monitoring system was used to compare and analyze with various stability methods, and to investigate the applicability of the methods for stability evaluation of agricultural reservoir. The horizontal displacement was abruptly increased when physical properties of soft clay reached its maximum values and therefore, the values of these properties could be used to the fundamental data for stability evaluation. The evaluation of the stability of agricultural reservoir was suggested to use the inclination of curve rather than critical line.

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Development of Slope Stability Analysis Method Based on Discrete Element Method and Genetic Algorithm I. Estimation (개별요소법과 유전자 알고리즘에 근거한 사면안정해석기법의 개발 I. 검증)

  • Park Hyun-Il;Park Jun;Hwang Dae-Jin;Lee Seung-Rae
    • Journal of the Korean Geotechnical Society
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    • v.21 no.4
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    • pp.115-122
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    • 2005
  • In this paper, a new method composed of discrete element method and genetic algorithm has been introduced to estimate the safety factor and search critical slip surface on slope stability analysis. In case of estimating the safety factor, conventional methods of slope analysis based on the limit equilibrium do not satisfy the overall equilibrium condition; they must make assumptions regarding the inclination and location of the interstice forces. An alternative slope analysis method based on the discrete element method, which can consider the compatibility condition between force and displacement, is presented. Real-coded genetic algorithm is applied to the search for the minimum factor of safety in proposed analysis method. This search method is shown to be more robust than simple optimization routines, which are apt to find local minimum. Examples are also shown to demonstrate the applicability of the proposed method.

Revegetation and human( I ) -Revegetation of face of the slopes in the future- (녹화(綠化)와 인간(人間)( I ) -앞으로의 비탈면 녹화(綠化)-)

  • Chun, Kun-Woo;Kim, Min-Sik;Iwamoto, Tohru;Ezaki, Tsugio
    • Journal of Forest and Environmental Science
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    • v.17 no.1
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    • pp.74-87
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    • 2001
  • When the revegetation of the slopes is required, it is more desirable to consider it from the ecological view point rather than from the disaster-preventive one because the environment is critical for the introduction of pioneer plants to the denuded slopes. The ecological point of view adheres to the maintenance of the present, original ecosystem of the construction area. The new revegetation technology is presented using native microorganisms and its effective usuage was discussed based on the data in the research field. Direct seeding is recommended and explained in detail than planting seedlings. The importance of inclination angle of slope face is shown for the successful revegetation from its relationship with the thickness of soil. It is indicated that the introduction of pilot plants to the slopes should include their ability to ease the acid rain effects as much as possible. Finally every construction may not be desirable for the maintenance and improvement of the global ecosystem without the consideration of the opinions mentioned above.

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Facial asymmetry: Critical element of clinical successful treatment (임상가를 위한 특집 4 - 안면비대칭의 외과적 교정)

  • Hong, Jongrak
    • The Journal of the Korean dental association
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    • v.52 no.10
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    • pp.623-632
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    • 2014
  • The facial asymmetries include maxillary, mandibular, and chin asymmetries, although the most common deformity is primarily in the mandible. Common causes of this type of asymmetry can include asymmetric growth of the condyle or the mandible. In these patients, the location of the Me would be deviated to the shorter side because of the asymmetric growth of the mandible, and, commonly, the maxillary occlusal plane would be tilted toward the deviated side because the maxilla likely grows asymmetrically according to the pattern of asymmetric mandibular growth. Three-dimensional CT images are ideal for evaluating the size and location of anatomic structures, and such reconstructed images allow the use of software that can show anatomic structures from numerous angles, allowing actual measurements of distances and angles without problems of magnification, distortion, or superimposition caused by 2-dimensional imaging. In the present study using 3D-CT imaging, the 8 parameters, including measurements of the upper midline deviation, maxillary canting in the canine and first molar regions, width of the upper arch, width of the mandible at the Go, vertical length of the ramus, inclination of the ramus, and deviation of the Me were easily measured. The dentition should be orthodontically decompensated and dental midline should ensure incisor midlines positioned in the midline of each jaw before surgical correction. Surgical correction could be considered such as canting or yawing correction in the frontal or horizontal aspect, respectively.

COMBINED ORTHODONTIC-SURGICAL TREATMENT FOR CLASS III PATIENT WITH MIDFACIAL DEFICIENCY AND MANDIBULAR PROGNATHISM (중안면부 함몰과 하악전돌을 동반한 III 급 부정교합자의 교정-악교정수술 복합치료)

  • Cho, Eun-Jung;Kim, Jong-Tae;Yang, Won-Sik
    • The korean journal of orthodontics
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    • v.26 no.5 s.58
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    • pp.637-645
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    • 1996
  • In non-growing Class III malocclusion, the critical aspects which determine the need of orthognatic surgery are the severity of skeletal discrepancy, incisor inclination, overbile and soft tissue profile. Two-jaw surgery is more effective in correcting severe sagittal, vertical, transverse skeletal discrepancies and facial asymmetry. And more esthetic and stable profile can be achieved by two-jaw surgery Some midfacial deficiency Patients can be treated by Pyramidal Le Fort II osteotomy to maintain infraorbital rim and malar complex and to advance nasomaxillary complex. Others who require advancement of infraorbital rim and malar complex can be treated by quadrangular Le Fort II osteotomy. On the following cases, patients who had represented midfacial deficiency and mandibular prognathism were treated with combined orthodontic-surgical therapy by Le Fort II osteotomy and BSSRO.

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