• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.2
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• pp.10-16
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• 2000

The purpose of this study is to identify relationships between a central angle and a radius of curvature of divided roads in flat terrain of traditional villages, suggesting layout criteria for traditional villages: Nak-an, Sung-Eup, Ha-Whe. This study is sought to find the optimum model through the various SAS regression analyses. a regression analysis of this data was adopted to induce the relationship formula between a central angle of curve and a radius of curvature. Results of this study are as follows: 1) Most of the divided roads in traditional villages have a complex curve rather than a simple curve. 2) A central angle of curve has ranged from 11$^{\circ}$to 127$^{\circ}$, with a mean degree of 63.9. 3) In the lower level of central angle(11-40$^{\circ}$), the branch roads have distributed with a high frequency, but with a low frequency in the higher level of central angle(90-140$^{\circ}$). 4) A radius of curvature in the divided roads has ranged from 0.9m to 59.6, but half of the roads have concentrated on 1-6m of the curvature. 5) Compared to the result of hilly villages in previous study(Ahn, 1999), value of central angels in flat villages is lower than that of hilly villages, while a mean value of the curvature is higher than that of hilly villages. 6) A Non-linear regression analysis, resulting from the SAS application, was useful method to induce a relationship formula between a central angle and a radius of curvature in the branch roads. Our study's formula is as follow: R=100.3*EXP(-0.06*$\delta$)+3.91. 7) Our study model has less error than that of the Kishizuka's method, being applicable to a broader range of the branch roads. 8) A minimum radius of curvature in our study has showed 3.9m, suggesting to reconsider applications of the Kishizuka's(5.8m) in the footpass design, In the study for this presupposition model the efficiency and utility of it can be estimated to grow large according to how much and how far it includes both extremes of data. This study is for the application to a design in future through the numerical formula of divided roads of various traditional villages. The studies from now on will be about the quasi-hilly quasi-hilly village and hilly village supplementing these factors more.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2016.09a
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• pp.6-10
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• 2016

• Wind and Structures
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• v.19 no.2
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• pp.219-232
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• 2014

The characteristics of turbulent boundary layers over hilly terrain depend strongly on the hill slope and upstream condition, especially inflow turbulence. Numerical simulations are carried out to investigate the neutrally stratified turbulent boundary layer over two-dimensional hills. Two kinds of hill shape, a steep one with stable separation and a low one without stable separation, two kinds of inflow condition, laminar turbulent, are considered. An auxiliary simulation, based on the local differential quadrature method and recycling technique, is performed to simulate the inflow turbulence be imposed at inlet boundary of the turbulent inflow, which preserves very well in the computational domain. A large separation bubble is established on the leeside of the steep hill with laminar inflow, while reattachment point moves upstream under turbulent inflow condition. There is stable separation on the side of low hill with laminar inflow, whilw not turbulent inflow. Besides increase of turbulence intensity, inflow can efficiently enhance the speedup around hills. So in practice, it is unreasonable to study wind flow over hilly terrain without considering inflow turbulence.

• Journal of Korean Society for Atmospheric Environment
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• v.12 no.4
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• pp.459-472
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• 1996

An experimental investigation on the wind flow over smooth bell-shaped two-dimensional hills with hill slopes (the ratio of height to half width) of 0.3 and 0.5 is performed in an atmospheric boundary-layer wind tunnel. Two categories of the models are used in the present investigation; six two-dimensional single-hills, and four continuous double-hills. The measurements of the flow field and surface static-pressure distribution are carried out over the Reynolds number (based on the hill height) of 1.9 $\times 10^4, 3.3 \times 10^4, and 5.6 \times 10^4$. The velocity profiles and turbulence characteristics are measured by the pitot-tube and X-type hot-wire anemometer, respectively. The undisturbed boundary-layer profile on the bottom surface of the wind tunnel is reasonably consistent with the power-law profile with $\alpha = 7.0 (1/\alpha$ is the power-law exponent) and shows good spanwise uniformities. The profiles of turbulent intensity are found to be consistent along the centerline of the wind tunnel. The measured non-dimensional speed-up profiles at the hill crest show good agreements with the predictions of Jackson and Hunt's linear theory. The flow separation occurs in the hill slope of 0.5, and the oil-ink dot method is used to find the reattachment points in the leeside of the hill. The measured reattachment points are compared with the numerical predictions. Comparisons of the mean velocity profiles and surface pressure distributions between the numerical predictions and the experimental results show good agreements.

• Journal of Forest and Environmental Science
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• v.9 no.1
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• pp.57-66
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• 1993

The purpose of this study is to offer detailed topographic information for substantially selecting the yarding machine for mechanized yarding operations, classifying the forest site by cluster analysis and principal component analysis, and investigating simultaneously the variables which give much influence on the classification of forest site in forestry build-up region (21, 477ha) of Chunchon Gun, Kwangweon Do. Ten topographic variables were used for the analysis. The results of study were as follows : 1) Gosung region (2, 252ha) was classified into hilly terrain (57%) and steep terrain (43%) and required the tractor prehauling system for the former one and the medium skyline system for latter one, respectively. 2) 65% of Gajung region (2,306ha) and 67% of Kwangpan region (2, 627ha) were classified into steep terrain fitted for the medium skyline system and the portion of both region showed the hilly terrain for the tractor prehauling system. 3) Jiam region (4, 591ha), consisted only of steep terrain, required the medium skyline system. 4) Gunja region (3, 400ha), Sudong region (3, 984ha) and Sinpo region (2, 340ha) were classified into steep terrain, requiring the medium skyline system, with 85%, 75%, and 75%, respectively.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.04a
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• pp.279-280
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• 2002

본 연구에서는 라그랑지안 확산모델(LDM; Lagrangian dispersion model)을 이용하여 평지 및 언덕지형에서의 연기확산을 수치모사하였다. 수치예측의 검증을 위하여 평지지형의 경우는 풍동실험 결과와 비교하고 언덕지형의 경우는 오일러리안 확산모델(EDM; Eulerian dispersion model)의 모사결과와 비교함으로써 언덕지형에서 오염물질의 확산특성을 연구하였다. (중략)

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.7 no.3
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• pp.219-229
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• 1996

Path loss prediction method, one of the most essential parts in measuring the service area in mobile telecommunication, has been developed for many years. But, wave propagation depends on many kinds of environmental factors such as frequency, distance, the heights of transmitting and receiving antenna and the terrain status(buildings in large city, hilly terrain, mountain). These are the main reasons that the propagation models developed in foreign environments can not fit into Korean propagation condition. In this paper, therefore, we performed the measurement in Korean terrain environment in pager frequency band after deviding the terrain characteristics into six types. With this measured data, we derived several curves that follows the long-term wave progagation behavior and developed the wave propagftion prediction model which calculates the field strength at any point in the service area. The proposed model estimates the field strength in two categories, LOS(line-of-sight), or non LOS. We applied this model using the digital terrain data base and compared with the measured data. The result shows that the errors were between 3~9dB, which turned out to be practical.

• Journal of the Korean Institute of Educational Facilities
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• v.21 no.2
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• pp.25-32
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• 2014

Many Korean university campuses are located on hilly terrain where the hierarchy of the path system is unclear. Therefore, it is difficult to analyze the pedestrian network through space syntax, in which only horizontal direction changes are considered as depths of space. The purpose of this study is to compare pedestrian movement patterns and space syntax analysis in order to find their relevance to each other and the relationship between them. We conducted a survey regarding the most-visited buildings and pathways at S-University, which is located on a hilly area in Seoul. The survey results were compared with the Space Syntax integration map by regression analysis. For the segments where the relationship between pedestrian volume and integration was weak, field observations were conducted. As a result, topographical aspects, functional aspects, and location aspects were observed as the main influential factors. In addition, the research proposes that adding an extra axial line per vertical directional change can potentially compensate for the low relevance of stairs. This study suggests the possibility and the necessity of three-dimensional space syntax programs and emphasizes the importance of campus planning for the pedestrian environment.

• International journal of advanced smart convergence
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• v.10 no.4
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• pp.256-262
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• 2021

In order for small electric vehicles to drive on hilly roads in Korea, methods to improve the climbing ability and power performance of vehicles should be taken. In order to improve the power performance of small electric vehicles, the performance of motors mounted on electric vehicles should be improved. However, if the performance of the motor is improved to improve the power performance of the electric vehicle, it is possible to lower the price competitiveness accordingly. In addition, the power consumption of the battery is rapidly increased to drive the high-performance motor, so in order to introduce the small electric vehicle into the domestic market, various problems must be overcome. In order to commercialize small electric vehicles that do not emit harmful exhaust gases to the human body in the hilly domestic terrain, it is effective to introduce a separate continuously variable transmission system that can improve the climbing ability and power transmission ability. In this study, we propose a proprietary model of continuously variable transmissions that can be applied to small electric vehicles. The proposed continuously variable transmission is equipped with a spring in the driving pulley and the driven pulley, and has the advantage of performing a shift that increases torque in a situation where the vehicle needs to increase torque when driving on a hill. In addition, the basic design for commercialization of the proposed continuously variable transmission was carried out, and the prototype manufactured and attached to the body of a small electric vehicle.

• Journal of Environmental Impact Assessment
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• v.32 no.6
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• pp.407-418
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• 2023

This study conducted an analysis of terrain change indicators in major development projects in Korea, examining the correlation between terrain change indicators to derive foundational terrain change metrics based on different land use and slope types. The aim is to contribute to sustainable development by enhancing the efficiency of land utilization and landscaping, while minimizing environmental impacts in future development endeavors. Additionally, to apply the research findings in practical contexts, domestic regulations related to terrain were surveyed, and the compatibility and usability between these regulations and research analysis results were discussed. Based on this, the study seeks to explore strategies for more accurate and useful utilization of terrain change indicators in future research. As a result, in the tourism development, terrain changes predominantly occur in the order of flat land, hillly land, and mountain land, with the analysis indicating higher terrain changes in undulating hilly and mountainous lands compared to flat land. Furthermore, in industrial complex development, very steep (20°-30°) and extreme (30°-40°) slopes; in urban development projects, steep slope (15°-20°); in athletic service facility and tourist development, steep (15°-20°) and very steep (20°-30°) exhibit higher average terrain change indicators compared to other slope categories. The findings of our study can contribute to the formulation of strategies aimed at minimizing terrain disturbance in future domestic development projects and serve as foundational data for environmental impact assessments.