• Title/Summary/Keyword: Height of obstacle

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A Proposal on the Improvement of Obstacle Limitation Surface and Aeronautical Study Method (장애물 제한표면과 항공학적 검토방법의 제도 개선에 관한 제언)

  • Kim, Hui-Yang;Jeon, Jong-Jin;Yu, Gwang-Eui
    • The Korean Journal of Air & Space Law and Policy
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    • v.34 no.1
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    • pp.159-201
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    • 2019
  • Along with Annex 14 Volume I establishment in 1951 and the set-up of restriction surface around the runway, aeronautical technique and navigation performance achieved dazzling growth, and the safety and precision of navigation greatly improved. However, restrictions on surrounding obstacles are still valid for safe operation of an aircraft. Standards and criteria for securing safety of aircraft operating around and on airport is stated in Annex 11 Air Traffic Services and Annex 14 Aerodrome etc. In particular, Annex 14 Volume I presents the criteria for limiting obstacles around an airport, such as natural obstacles such as trees, mountains and hills to prevent collisions between aircraft and ground obstacles, and artificial obstacles such as buildings and structures. On the other hand, Annex 14 Volume I, in the application of the obstacles limitation surfaces, apply the exception criteria, as it may not be possible to remove obstacles that violate the criteria if the aeronautical study determines that they do not impair the safety and regularity of aircraft operation. Aeronautical study has been applied and implemented in various countries including United States, Canada and Europe etc. accordingly, Korea established and amended some provisions of the Enforcement rules of the Aviation Act and established the Aeronautical study guidelines to approve exceptions. However, because ICAO does not provide specific guidelines on procedures and methods of Aeronautical study, countries conducting aeronautical study have established and applied their own procedures and methods. Reflecting this realistic situation, at the 12th World Navigation Conference and at the 38th General Assembly, the contracting States demanded a reexamination of the criteria for current obstacle limitation surfaces and methods of aeronautical study, and the ICAO dedicated a team of experts to prepare new standard. This study, in line with the movement of international change in obstacle limitation surface and aeronautical study, aims to compare and analyze current domestic and external standards on obstacle limitation and height limits, while looking at methods, procedure and systems for aeronautical study. In addition, expecting that aeronautical study will be used realistically and universally in assessing the impact of obstacles, we would recommend the institutional improvement of the aeronautical study along with the development of quantitative analysis methods using the navigation data in the current aeronautical study.

A Chronological and Legal Study on Mitigation of Height Restriction in Flight Safety Zone around Airports - Mostly Regarding Civilian Airports - (공항 비행안전구역 고도완화의 연혁적 고찰과 해결방안에 관한 정책적·법적 고찰 - 민간 공항 중심으로 -)

  • Shin, Sung-Hwan
    • The Korean Journal of Air & Space Law and Policy
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    • v.35 no.2
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    • pp.225-246
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    • 2020
  • More than technical or academic matter, mitigation of height restriction around airports is about up-dating out-dated policies that have not kept up with rapidly developing aircraft and air traffic control technologies. Above all, instead of calling out 'flight safety' that the public do not comprehend, it is important to examine and carry out measures that can protect people's right of property. MOLIT(Ministry of Land, Infrastructure, and Transport) after reviewing ICAO's Obstacle Limitation Surface TF, made an announcement to provide further plans that would apply to contracting states from 2026. However, residents of redevelopment areas near Kimpo international airport asserted that MOLIT's policy overlooks the reality of the redevelopment zone. ICAO, UN's specialized agency for civilian aviation, recommends in Annex 14, 4.2.4 that contracting states conduct an aeronautical study to determine the flight safety of horizontal surface(45m), excluding approach surface, and to mitigate height restrictions if no threat is found. Numerous countries including the United States have been following this recommendation and have been able to effectively protect people's right of property, whereas the South Korean government have not following it so far. The number of height restriction mitigation cases in the recent three months (2019. 7. 15~10. 14.) FAA of the United States have allowed after conducting an aeronautical study reaches 14,706. Japan and Taiwan also reconstruct airspace around airports in metropolitan areas in order to protect people's right of property. Just as the United States is following, MLIT should follow ICAO's recommendation in Annex 14. 4.2.4(Vol. 1. Airport Construction / Operation) and protect people's right of property by first applying aeronautical studies to the horizontal surface(45m) of flight safety zones until the specifics of ICAO's 2026 TF materialize.

A Study on Characteristics of Landscape in the High-rised Apartment in Small town - Centering of Small town in Jeollanam-do - (소도시에서 고층 아파트의 경관적 특성에 관한 연구 - 전라남도 소도시를 중심으로 -)

  • Kim, Yun-Hag;Jung, Jin-Hwan;Yoo, Chang-Geun;Cho, Yong-Joon
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2005.11a
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    • pp.223-228
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    • 2005
  • This study examined and analyzed locational conditions of apartment houses in regional small cities to provide basic materials to set direction and index of view management of apartment house and thus the results of the study are as follows. 1. The number of story of apartment houses 'below five story' was 48% and area of apartment house was 'over 500m$^2$ and below 1000m$^2$' in 31% of the whole regions. 2. As a result of analyzing correlations with changes of floor of apartment house by construction year, apartment houses below 10 story were mainly built between 1991 and 1995 and high-storied apartment houses over 11 story were mainly built since 1995 and apartment houses over 21 story were built since 2000 and these high-storied apartment houses were main cause of hindering view of small cities. Accordingly, establishment of guideline of building high-storied apartment house which can be a primary obstacle of urban view and regulations of height are needed.

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A Study on Establishing the Range of Optimum Size for School Sports Hall - Focused on the regulations of sports facilities in Japan, England, Germany, U.S.A - (학교(學校) 스포츠홀의 적정규모(適定規模) 범위설정(範圍設定)에 관한 연구(硏究) - 일본(日本), 영국(英國), 독일(獨逸), 미국(美國)의 체육시설(體育施設) 규정(規定)을 중심(中心)으로 -)

  • Kim, Hyo-Il
    • Journal of the Korean Institute of Educational Facilities
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    • v.7 no.3
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    • pp.23-35
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    • 2000
  • Today the supply of school sports halls for multi-functional use is absolutely insufficient in school facilities of Korea. For economical reasons and efficiency of use, a joint utilization of these halls by schools, sports clubs and other users should be strived for. This will lead, as a result, to a minimization overall in the demand for halls. Above all to satisfy this demand, the regulations of sports facilities suitable to the students' standards of play and physical conditions must be preceded in Korea. And a study on the architectural planning of this hall size for primary, middle and high school is needed. This study aims at establishing the range of optimum size of school sports hall in Korea by surveying and analyzing the regulations of sports facilities about clear height of hall, obstacle-free zone and court area in Japan, England, Germany and U.S.A. Therefore, this study will offer valuable basic data in planning the school sports hall.

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Comparing Nutrition Knowledge, Eating Habits, and Neonatal Health Status of Primipara for Pregnant Women of Advanced Maternal Age Compared to Those of Younger Ages (고령 초산모와 비고령 초산모의 임신영양지식, 식습관 및 신생아 건강상태 비교)

  • Lee, Sun-Ok;Park, Kyung-Yeon;Han, Mi-Jung
    • Women's Health Nursing
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    • v.21 no.4
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    • pp.253-261
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    • 2015
  • Purpose: The aim of this study was to examine differences in nutrition knowledge, eating habits during pregnancy, and neonatal health status between primipara for pregnant women of advanced maternal age in comparison to those under the age of 35. Methods: This study used a comparative survey design. Data were collected through self-report questionnaires and patients medical records. A total of 127 participants, mothers after delivery were recruited from metropolitan city B. Results: Primipara in advanced maternal age (n=32) reported significantly higher scores of eating habits (Z=-2.96, p=.003) than younger ages (n=95). There were no significant differences in scores of pregnancy nutrition knowledge (Z=-0.44, p=.660), duration of gestation (Z=-0.28, p=.778), neonatal birth height (Z=-0.10, p=.924), neonatal birth weight (Z=-0.28, p=.777), Apgar score 1 minute (Z=-0.53, p=.599) and 5 minutes (Z=-0.23, p=.816) between two groups. Conclusion: It concludes that age is not the obstacle to the best nutritional status of women and their newborns.

Numerical Simulation of Air Flow and Gas Dispersion around Obstacles

  • Nguyen The-Due;Park Warn-Gyu;Duong Ngoe-Hai
    • 한국전산유체공학회:학술대회논문집
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    • 2003.10a
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    • pp.253-254
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    • 2003
  • Computations of the mean and turbulence flows over three-dimensional hill of conical shape have implemented. Beside the standard ${\kappa}-{\varepsilon}$ , two other modifications proposed by Detering & Etling and Duynkerke for atmospheric applications were also considered. These predictions were compared with the data of a wind tunnel experiment. From the comparison, it was concluded that all three models predict the mean flow velocities equally well while only the Duynkerke's model accurately predicts the turbulence data statistics. It also concluded that there are large discrepancies between model predictions and the measurements near the ground surface. The flow field, which was obtained by using the Duynkerke's modification, was used to simulate gas dispersion from an upwind source. The calculation results are verified based on the measurement data. Modifications of the turbulent Schmidt number were carried out in order to match the measured results. The code was used to investigate the influence of the recirculation zone behind a building of cubical shape on the transport and dispersion of pollutant. For a stack behind and near the obstacle, some conclusions about the effect of the stack height and stack location were derived.

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Numerical Simulation of Air Flow and Gas Dispersion around Obstacles

  • Nguyen The-Duc;Duong Ngoc-Hai;Park Wam-Gyu
    • 한국전산유체공학회:학술대회논문집
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    • 2003.08a
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    • pp.144-151
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    • 2003
  • Computations of the mean and turbulence flows over three-dimensional hill of conical shape have implemented. Beside the standard $\kappa-\epsilon$, two other modifications proposed by Detering & Etling and Duynkerke for atmospheric applications were also considered. These predictions were compared with the data of a wind tunnel experiment. From the comparison, it was concluded that all three models predict the mean flow velocities equally well while only the Duynkerke's model accurately predicts the turbulence data statistics. It also concluded that there are large discrepancies between model predictions and the measurements near the ground surface. The flow field, which was obtained by using the Duynkerke's modification, was used to simulate gas dispersion from an upwind source. The calculation results are verified based on the measurement data. Modifications of the turbulent Schmidt number were carried out in order to match the measured results. The code was used to investigate the influence of the recirculation zone behind a building of cubical shape on the transport and dispersion of pollutant. For a stack behind and near the obstacle, some conclusions about the effect of the stack height and stack location were derive

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Development of Ergonomic Walking Assistance Robot for the Elderly and the Infirm (노약자들을 위한 인체공학적 보행 보조 로봇의 개발)

  • Kim, Jung-Yup
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.22 no.3_1spc
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    • pp.600-606
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    • 2013
  • This paper describes the development of a novel walking assistance robot for the elderly and infirm. In the case of simple walking assistance devices, the walking safety and effectiveness are somewhat low; hence, caregivers are frequently required. The walking assistance robot developed in this research is capable of securely and conveniently assisting a walking user by using electric motors and various devices without a caregiver. The main features include the following. First, the walking safety is improved by using a pelvis supporter, and the robot is able to follow the user effectively by means of ergonomic motion sensors and electric powered wheels. Second, it is possible to adjust the load applied to the lower body by adjusting the height of the pelvis supporter. Finally, it is possible to inform the approximate distance and direction of any obstacle around the robot using the sounds and vibrations for the blind and the hearing impaired. The performance of the developed walking assistance robot was successfully verified using a walking assistance test in a narrow-corridor environment.

Numerical and wind tunnel simulation of pollutant dispersion in the near wake of buildings

  • Wang, X.;McNamara, K.F.
    • Wind and Structures
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    • v.8 no.6
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    • pp.427-442
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    • 2005
  • Numerical and wind tunnel simulations of pollutant dispersion around rectangular obstacles with five aspect ratios have been conducted in order to identify the effects of flow patterns induced by buildings on plume dispersion in the near wake of buildings. An emission from a low source located upwind of obstacles was used in this simulation. The local flow patterns and concentrations around a cubical obstacle were initially investigated using three RANS turbulence models, (the standard $k-{\varepsilon}$, Shear Stress Transport (SST), Reynolds-Stress RSM turbulence model) and also using Large-eddy simulation (LES). The computed concentrations were compared with those measured in the wind tunnel. Among the three turbulence models, the SST model offered the best performance and thus was used in further investigations. The results show, for normal aspect ratios of width to height, that concentrations in the near wake are appreciably affected because of plume capture by the horseshoe vortex and convection by the vertical vortex pairs. These effects are less important for high aspect ratios. Vertical vortex pairs present a strong ability to exchange mass vertically and acts efficiently to reduce ground-level concentrations in the near wake.

Effects of Uniform and Turbulent Inflow Conditions on Wake Topology and Vortex Growth Behind a Ramp (균일 및 난류 입구조건이 램프 후류 형상 및 성장에 미치는 영향)

  • Lokesh Kalyan Gutti;Mustafa Z. Yousif;Hee-Chang Lim
    • Journal of the Korean Society of Visualization
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    • v.21 no.2
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    • pp.24-33
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    • 2023
  • This work is to observe the wake flow generated behind a ramp. We have conducted a large eddy simulation with two ramp models having different heights with two different inflow conditions. Reynolds number based on the height of the large ramp (LR) and small ramp (SR) are Reh = 2.8×104 and 1.4×104 respectively. The wake flow visualization shows the formation of streamwise counter-rotating vortices pairs at the downstream of the obstacle. These primary vortices are stretched and lifted up when moving downstream. In order to observe the effect of the inflow condition on the wake transition, two different inlet flow conditions are given on the inlet section as an inlet boundary condition. Induced counter-rotating vortices pairs due to sharp-edged triangular ramp obstacles are developed and propagated downstream. In the result, the large ramp shows a more complicated wake structure of the boundary layer than the small ramp.