• Title/Summary/Keyword: Height and location

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Aerodynamic Performance Dependency on the Geometric Shape and Mounting Location of OSRVM (OSRVM의 형상 및 장착 위치가 차량의 공력성능에 미치는 영향)

  • Han, Hyun Wook;Park, Hyun Ho;Kim, Moon Sang;Ha, Jong Paek;Kim, Yong Nyun
    • Transactions of the Korean Society of Automotive Engineers
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    • v.21 no.3
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    • pp.30-42
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    • 2013
  • This study investigates the effects of OSRVM mounting location and its configurations such as stalk height and housing height on the aerodynamic performance of the passenger car. In order to validate the flow solver, FLUENT which is very well known commercial code, the flow field around an Ahmed Body was analyzed numerically and compared with the experimental data. The predicted aerodynamic performance and flow patterns around a car show good agreements with the experimental data. Mounting location and stalk height should be designed while OSRVM is mounted on the car to evaluate the aerodynamic performance precisely. Housing height, however, may be designed independent of the car because the aerodynamic interference between housing height and car configuration is negligible.

A Experimental Study on the Measurement and Estimation of Vehicle Center of Gravity (차량무게중심의 측정 및 추정에 관한 연구)

  • Lee, Myung-Su;Kim, Sang-Sup
    • Transactions of the Korean Society of Automotive Engineers
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    • v.18 no.5
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    • pp.91-99
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    • 2010
  • The center of gravity on vehicle is a fundamentally important point for assessing and measuring the characteristics of vehicle dynamics. Especially, the center of gravity height on vehicles is the closest factor with respect to rollover accidents in a social issue nowadays. In this paper, the center of gravity height in conjunction with vehicle parameters of vehicle weight, driving axle and roof height after measured by vehicle weight and loading location by means of VCGM developed by KATRI with good performance that the accuracy was less than 0.6% and repeatability 0.3% for vehicles being used in the whole world was observed. As a result of study, the location of center of gravity height on vehicle was able to be estimated with only roof height on vehicle.

The study on the height standard and the slenderness ratio according to location types of Mixed-use Residential Tall buildings (초고층 주상복합건축물 입지유형에 따른 높이기준 및 세장비 제안에 관한 연구)

  • Sung, Lee-Yong;Kim, Yun-Jun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.6
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    • pp.2779-2788
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    • 2012
  • The housing market is now difficult because of excess of the increase rate of housing and long-term recession but high-rise mixed-use buildings can mix residential facilities with various demand facilities focusing and they have the advantages to secure open space and excellent view by high-rise apartment. But there are problems by hindrance of skyline formation and height of buildings. Therefore, the purpose of this study is to suggest the height standard and the slenderness ratio to location types of Mixed-use Residential Tall buildings. For the method of the study, term arrangement through literature search and the precedent research survey were first done, the level of urban design and the details related to the height of buildings were done as the case research focusing on the 16 cases in Seoul. The following results were drawn by suggesting the height standard and the slenderness ratio by location type based on them. First, the height of mixed-use building by location type in the level of urban design gets higher starting from the secondary center of the city and can be suggested as from less than 150m to more than 200m. Second, the slenderness ratio shall be planned as more than 1:3 because the area of the ground level of mixed-use building is large unlike Mixed-use Residential Tall buildings and visual passage shall be placed so that unity of openness and group formation will be planned. Third, for the height related to Mixed-use Residential Tall buildings, amendment of the special architectural district system and the special law related to super high-rise buildings shall be enacted.

Estimation of Person Height and 3D Location using Stereo Tracking System (스테레오 추적 시스템을 이용한 보행자 높이 및 3차원 위치 추정 기법)

  • Ko, Jung Hwan;Ahn, Sung Soo
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.8 no.2
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    • pp.95-104
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    • 2012
  • In this paper, an estimation of person height and 3D location of a moving person by using the pan/tilt-embedded stereo tracking system is suggested and implemented. In the proposed system, face coordinates of a target person is detected from the sequential input stereo image pairs by using the YCbCr color model and phase-type correlation methods and then, using this data as well as the geometric information of the stereo tracking system, distance to the target from the stereo camera and 3-dimensional location information of a target person are extracted. Basing on these extracted data the pan/tilt system embedded in the stereo camera is controlled to adaptively track a moving person and as a result, moving trajectory of a target person can be obtained. From some experiments using 780 frames of the sequential stereo image pairs, it is analyzed that standard deviation of the position displacement of the target in the horizontal and vertical directions after tracking is kept to be very low value of 1.5, 0.42 for 780 frames on average, and error ratio between the measured and computed 3D coordinate values of the target is also kept to be very low value of 0.5% on average. These good experimental results suggest a possibility of implementation of a new stereo target tracking system having a high degree of accuracy and a very fast response time with this proposed algorithm.

Optimum location of second outrigger in RC core walls subjected to NF earthquakes

  • Beiraghi, Hamid;Hedayati, Mansooreh
    • Steel and Composite Structures
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    • v.38 no.6
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    • pp.671-690
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    • 2021
  • Seismic responses of RC core wall with two outriggers are investigated in this study. In the models analyzed here, one of the outriggers is fixed at the top of the building and the second is placed at different levels along the height of the system. Each of the systems resulting from the placement of the outrigger at different locations is designed according to the prescriptive codes. The location of the outrigger changes along the height. Linear design of all the structures is accomplished by using prescriptive codes. Buckling restrained braces (BRBs) are used in the outriggers and forward directivity near fault and far fault earthquake record sets are used at maximum considered earthquake (MCE) level. Results from nonlinear time history analysis demonstrate that BRB outriggers can change the seismic responses like force distribution and deformation demand of the RC core-walls over the height and lead to the new plastic hinge arrangement over the core-wall height. Plasticity extension in the RC core wall occurs at the base as well as adjacent to the outrigger levels. Considering the maximum inter-story drift ratio (IDR) demand as an engineering parameter, the best location for the second outrigger is at 0.75H, in which the maximum IDR at the region upper the second outrigger level is approximately equal to the corresponding value in the lower region.

Effect of droplet protection screen height on the prevention ability of infectious droplet airborne transmission in closed space (밀폐공간에서 비말 가림막 높이에 따른 감염성 비말 공기전파 차단능력 평가)

  • Heo, Jieun;Cho, Hee-joo;Park, Hyun-Seol;Shin, Dongho;Shim, Joonmok;Joe, Yun-Haeng
    • Particle and aerosol research
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    • v.17 no.2
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    • pp.37-42
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    • 2021
  • Although the installation of droplet protection screen (DPS) is known to prevent droplet transmission, there is still a lack of knowledge in effectiveness of DPS installation to block the airborne transmission. In this study, the prevention ability of DPS against airborne transmission was evaluated according to the DPS height. When the DPS was not installed, the maximum concentration of PM1.0 at the location opposite to infected person was 35% of that at the infected person location. When the DPS was installed, the DPS effectively prevented the airborne transmission, consequently approximately 7% of generated particles were measured at the opposite location from particle generation position (infected person location). The prevention ability of DPS increased with DPS height, the maximum prevention efficiency of 95.1% was obtained when the DPS height was 900mm. Moreover, the speed of airborne transmission was delayed by installation of DPS, and the delay time increased with DPS height.

Evaluation of available height, location, and patency of the ostium for sinus augmentation from an implant treatment planning perspective

  • Vaddi, Anusha;Villagran, Sofia;Muttanahally, Kavya Shankar;Tadinada, Aditya
    • Imaging Science in Dentistry
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    • v.51 no.3
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    • pp.243-250
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    • 2021
  • Purpose: The objective of this study was to evaluate the amount of height available for a maxillary sinus augmentation procedure without blocking the ostium and jeopardizing the drainage of the ostiomeatal complex using cone-beam computed tomography (CBCT) imaging. Materials and Methods: A total of 200 sinonasal complexes comprising 100 dentate and 100 edentulous scans were retrospectively assessed using CBCT. Invivo 5.0, a CBCT reconstruction program, was used for image evaluation. The coronal section demonstrating the ostiomeatal complex was selected as a reference view to perform measurements of the sinus. The measurements were done by 2 evaluators in separate sessions. Comparative analyses of measurements were performed between dentate and edentulous patients and between male and female patients. Results: The safe height to which the sinus can be elevated without compromising the integrity of the ostiomeatal complex was calculated for each sinus. In the presence of significant mucosal thickening, the height available for augmentation was calculated by subtracting the height of mucosal thickening from the sinus floor to the location of the ostium. In this study, the available height was approximately 27.05 mm for dentate and 23.40 mm for edentulous patients. The inter-operator reliability was excellent for all the parameters evaluated. Conclusion: This retrospective study with a limited number of patients from a single university-based site shows that CBCT is valuable in evaluating the location and patency of the ostium for planning sinus augmentation procedures for dental implant placement.

A Parametric Study on Design Variables of Lifting Chamber Using Numerical Simulation (수치해석을 이용한 부양실 설계변수에 관한 연구)

  • Jeon, Chang-Soo
    • Journal of computational fluids engineering
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    • v.3 no.2
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    • pp.52-64
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    • 1998
  • Numerical simulations on the flowfield of lifting chamber for Wing-In-Ground vehicle were performed using Fluent/UNS 4.2 software. The trend of lifting force in lifting chamber and parametric study of geometric and fluid variables were primarily investigated. Selected parameters for investigation are inlet velocity, height between chamber and water level, depth of the skirt, location of inlet, variaton of height at bow and stern. Also, air capturing capabilities from downstream of the propeller were evaluated at the air inlet. The lifting force was increased linearly with the increased of inlet velocity and nonlinearly with the decrease of height force was increased with increased depth. It turned out to have very minor effect on lifting force to change the location of air inlet for lifting chamber, installed on top surface. Tilting the vehicle when it was lifted, the lifting forces, generated in each case, showed no appreciable changes.

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Optimization of Shroud Shape and Fan Location for Increasing Exhaust Flow Rate of Air Conditioner Outdoor Unit (실외기 토출 유량 증대를 위한 Shroud 형상 및 휀 위치 최적 설계)

  • Ryu, Ki-Jung;Kim, Yoo-Yil;Lee, Kwan-Soo;Cha, Woo-Ho
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.21 no.11
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    • pp.599-605
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    • 2009
  • This paper presents a numerical evaluation of the flow rate of air conditioner outdoor unit by investigating the effects of fan location and shroud shape. To determine optimal design parameters, we investigated the exhaust flow rate by changing shroud height, fan height, fan guide height, and fan width. The 3rd order central composite design was performed to select three most important parameters affecting the exhaust flow rate. According to the result of response surface method, the exhaust flow rate of the optimum model increased by 6.25% compared to that of the base model.

Location of Back-shu Points of the Bladder Meridian in the Lumbar Region through Patient Measurement

  • Sim, Ho-Yun;Park, Sang Kyun;Lee, Kwang Ho
    • Journal of Acupuncture Research
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    • v.35 no.1
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    • pp.37-40
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    • 2018
  • Background: The purpose of this study was to compare the first branch of the bladder meridian (FBBM) as determined by the proportional bone measurement method (PBMM), to the line formed by the erector spinae muscle group, and to establish an academic basis for selection of acupuncture points and needling. Methods: Sixty participants were divided into 3 groups based on body mass index (BMI) and into 2 groups based on waist/height ratios. The distance from the midline of the spine to the first branch of the bladder meridian with PBMM (DFBBM), and the distance from the midline of the spine to the most elevated fleshy region of the erector spinae (DMEFR), at the same level as the inferior border of the spinous processes of L1-L5, were measured. The DFBBM and the 5 DMEFRs were then analyzed according to BMI and the waist/height ratio. Results: DFBBM was statistically different from DMEFR in all back-shu points in the lumbar region. DFBBM was not significantly different from DMEFR in the groups with a high BMI or waist/height ratio. However, there was a statistical difference in the groups with a low or moderate BMI or low waist/height ratio. Conclusion: Since the location of the most elevated fleshy region of the erector spinae does not coincide with the location of the FBBM, the selection of back-shu points in the lumbar region must be performed precisely by PBMM.