• Title, Summary, Keyword: Take-off

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Analysis of Impulse Force and Kinematic Factors of the Limbs during Stefan Holm's Take-off Phase and Penultimate Stride of High Jump (Stefan Holm의 높이뛰기 발구름 동작에서의 충격력과 상지와 하지 분절의 운동학적 분석)

  • Lee, Jin-Taek
    • Korean Journal of Sport Biomechanics
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    • v.21 no.1
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    • pp.97-105
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    • 2011
  • The purpose of this study was to investigate the kinetic factors of Stefan holm's take-off motion and provide the technical data. Collected data of the subject(height: 181 cm, weight: 71 kg, record: 230 cm) were used for the last two strides and take-off phase. The results were as follows: The vertical impulse force was 2044.8 N which was 2.49 times and the anterior-posterior impulse force was -1306.4 N which was 1.88 times of the subject's weight. The take-off leg angular velocities($\omega_x,\;\omega_y$) were switched drastically from clockwise to count clockwise direction between two-step touchdown and take-off. The highest jerk of the take-off foot was 368.97 m/s3 during the two step take-off and the take-off foot made an impact to the ground with 1225.07 m/s3 during the one step touchdown.

An Accuracy Analysis on Quantity Take-off Using BIM-based Spatial Object (BIM 기반의 공간객체를 이용한 물량산출 정확성 분석)

  • Cha, You-Na;Kim, Seong-Ah;Chin, Sang-Yoon
    • Journal of KIBIM
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    • v.4 no.4
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    • pp.13-23
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    • 2014
  • After being introduced, Building Information Modeling (BIM) has been actively applied to the cost estimation of construction projects, and various studies on BIM based quantity take-off have been carried out. In practice, however, these calculations take considerable time, because BIM based quantity take-off is further conducted along with 2D-based quantity take-off. Studies on the quantity take-off using BIM spatial objects have been carried out on early stages of projects, but how this method differs from the existing quantity take-off method and how accurate it is in comparison have rarely been verified. Therefore, by comparing 2D based quantities with quantities through BIM spatial objects, this study analyzed the accuracy of quantity take-off using BIM spatial objects. To this end, the properties of BIM spatial objects and quantity calculable spatial types were analyzed, and existing 2D-based quantities and quantities extracted from BIM spatial objects were compared through a case study. As a result, the quantity of spatial objects found to be more by about 7.13% in 0.05% and therefore, this difference should be considered during quantity take-off using BIM spatial objects. Through the results of this study, we can improve the accuracy of quantity take-off using BIM spatial objects in the early stage of a construction project.

Parametric Quantity Take-Off of Earthwork by Comparing the Use of Surface and Solid Models (Surface 및 Solid 방식의 비교를 통한 Parametric 기법의 토공물량산출 방법)

  • Hwang, Hee-Su;Lee, Jae-Hong;Kim, Tae-Young
    • Journal of KIBIM
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    • v.8 no.1
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    • pp.56-62
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    • 2018
  • There exists no precedented case of quantity take-off, using parametric modeling, from BIM-based irregular structures. Civil 3D provides earthwork quantity take-off based on surface modeling. Generally, designers should enter data into the specification additionally after extracting quantity estimation from earthwork modeling design. The objective of this report is to suggest the method from quantity take-off to specification of BIM-based earthwork quantities. We intend to investigate earthwork take-off method by Civil3D and explain why parametric information extraction is required for quantity estimation and specification and how information of earthwork quantity based on solid and surface modeling is connected to open quantity take-off module. It is highly expected that this suggestion would be the practical methodology of earthwork quantity take-off and specification in the field of civil engineering.

Allometric Relations of Take-off Speed and Power with Body Mass of Anuran Amphibians

  • Choi, In-Ho;Shin, Jae-Seung;Kim, Mi-Hyun
    • Animal cells and systems
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    • v.2 no.4
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    • pp.477-481
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    • 1998
  • Previous studies have postulated that isometric animals exert similar locomotory capacity (speed, distance) because the amount of energy available for the motion would be the same regardless of body mass (m). To test propriety of this theory, we examined body shape and take-off potential of two frog species, Rana nigromaculata (powerful jumpers) and Bombina orientalis (slow hoppers). Morphological measurements included thigh muscle mass (indicative of total muscle force), hindlimb length (L, determining acceleration distance), and interilial width (shaping take-off motion). To gauge locomotory capacity, take-off speed (v) and take-off angle ($\theta$) were measured from video analyses, and jump distance (R) and take-off Power ($P_{t}$ ) were calculated from equations $R=V^{2}sin2\theta/g$ and ($P_{t}$$㎷^{3}/2L$(where g is the gravitational constant). Scaling exponents of morphometric variables for both species were 0.96-1.11 for thigh muscle mass, 0.28-0.29 for hindlimb length, and 0.30-0.36 for interilial width. Scaling exponents of locomotory performance for the two species were -0.01-0.14 for take-off speed, 0.24-0.31 for jump distance, and 0.66-0.84 for take-off power. The results demonstrate that the frogs of this study showed isometric body shape within species, but that take-off response changed allometrically with body mass, indicating that these data did not fully support the previous proposition. An exception was found in take-off speed of B. orientalis, in which the speed changed little with body mass (slope=-0.01). These findings suggest that the energy availability approach did not properly explain the apparent allometric relations of the take-off response in these animals and that an alternative model such as a power production approach may be worth addressing.

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Estimation of WIGs' Take-off State Based on Planing Theory (활주선의 정상 활주 상태 모델을 이용한 WIG선의 이수 상태 추정)

  • Yeo, Dong-Jin;Yoon, Hyeon-Kyu;Lee, Chang-Min
    • Journal of the Society of Naval Architects of Korea
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    • v.44 no.5
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    • pp.534-541
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    • 2007
  • This paper suggests the mathematical method for the estimation of the required engine output for WIG crafts. The engine size of a WIG craft Is a key parameter in the design stage, because WIGs should overcome the hump drag during the take-off. Therefore, it is very important for a WIG designer to estimate required power and state change during take-off. The mathematical method was developed based on the steady planing state model of a planing boat. Through numerical calculations on various take-off states, it was found that the suggested method could give reasonable estimation of required power and state change during take-off.

The Kinematics Analysis of Round-off at end of Beam-salto Backward Stretched with Step-out to Cross on Balance Beam (평균대 도움 짚고 몸 펴 뒤 공중 돌아 오르기 동작에 대한 운동학적 분석)

  • Kim, Young-Ran
    • Korean Journal of Sport Biomechanics
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    • v.13 no.3
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    • pp.99-116
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    • 2003
  • The purpose of this study was to kinematics factors on during round-off at end of beam-salto backward stretched with step-out to cross on balance beam. Four elite female gymnastics players participated as subject of this study. The methods of this study was analyzed using three dimentional analysis. The results and conclusion of this paper is obtained as follows ; 1. The phase of time was the most short time in board touch down phase and board take-off phase. Also, it was shown a more long time in total time compared to previous study. 2. The horizontal displacement of each phase was shown the most high levels in balance beam landing. The vertical displacement was display a non-linearity increase in board take-of phase, and it was shown the most high levels in vertical displacement during landing of balance beam. 3. The horizontal velocity of each phase was shown the most high levels in board touch down, and it was display a gradually decreased levels because flight during board take-of. The resultant velocity of CG on each phase was shown the most high levels in board touch down and board take-off. 4. The angle of hip joint was shown the most high levels as performed a motion in extension state during board take-off, and the angle of knee joint was display a increased levels because of flight cause body extension in board take-off. Also the angle of ankle joint was shown a increasing levels during board take-off. Considering to this results, it is suggest that the change of kinematics factors in board touch down and board take-off is key role on the effective board control.

A Kinematics Analysis of Back Armstand 2 Somersault in Platform Dives a Case Study (플랫폼 다이빙 624C동작의 운동학적 사례분석)

  • Lee, Jong-Hee;So, Jae-Moo;Lim, Young-Tae
    • Korean Journal of Sport Biomechanics
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    • v.16 no.4
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    • pp.13-20
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    • 2006
  • A platform diving with categorizing 624C motion was video taped and 3D kinematic variables were analyzed. This motion is consist of 3 parts from the headstand position to the act of turning after take-off. The results indicated that it took a very short time from the moment of take-off to the act of 1/2 turning because the turning motion has already started from preparing motion even before the fingertips have parted from the ground. Also, there was barely any jumping height due to the use of upper limbs segment and there was little difference in the moving distance compared to the standing events judging from horizontal movement of 1.1m. The horizontal velocity of the center of human body was increased before take-off while the vertical velocity was decreased right after take-off and the velocity of lower limbs segment was faster than the upper limbs segment showing contrary results to the standing events. In the aspects of angular velocity, the upper limbs segment starts the turning motion when take-off by rapidly extending its angular velocity while lower limbs segment make large angular velocity even before take-off.

A Basic Study on an Application of Quantity Take-Off Requirements for Open BIM-based Schematic Estimation of Architectural Work (개방형BIM기반의 건축공사 개산견적을 위한 물량산출 적용지침 활용방안 기초 연구)

  • Kim, Inhan;Um, Sung-Gon;Choi, Jungsik
    • Korean Journal of Computational Design and Engineering
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    • v.20 no.2
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    • pp.182-192
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    • 2015
  • In recent years, numerous studies have attempted to extract quantity data by using Building Information Modeling (BIM). In terms of open-BIM based quantity take-off at the early design stage, only few studies were conducted in the field of cost engineering. A lack of compatibility of open BIM for information exchange is postulated as the cause. The Industry Foundation Classes (IFC) extension model has been developed to accommodate the interoperability with quantity take-off software. Improvement of open BIM for quantity take-off needs exchange requirements and model guidelines. For this purpose, the quantity data of IFC models were analyzed using BIM analysis tools. This paper also provides a proposal of requirements on open BIM based quantity take-off at the early design stage. Further this study have been develop the interface system for open BIM based quantity take-off requirements with the results on this study.

Mathematical Modelling of the Tension Behavior for the Let-off Mechanism Driven by an Individual Motor (송출 및 권취 장력제어 시스템 개발에 관한 연구(II);장력거동의 수학적 모델링)

  • Huh, You;Jang, Seung-Ho;Lee, Suck-Gyu
    • Textile Science and Engineering
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    • v.35 no.9
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    • pp.569-576
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    • 1998
  • In the weaving process the variations of the warp yarn tension cause irregularities of the weft density of the woven fabrics. Due to the fact that warp yarn tension varies in a great extent depending on the ratios of the take-up and the let-off speed, it is necessary to regulate the speed of let-off in relation to that of take-up operation for keeping warp yarn tension in a certain range allowable for the fabric quality. Therefore it is indispensable to analyze the dynamic characteristics of the take-up and let-off system for obtaining the weaving process optimally. In this research it was tried to get the dynamic characteristics of the let-off/take-up process theoretically, and the behavior of the warp yarn tension was simulated on the basis of the mathematical model, depending on the let-off and take-up speed, tensile properties and feeding tension of the warp yarns. From this research the following results could be obtained: 1) dynamic warp yarn tension can be described by a differential equation, however, nonlinearly with respect to the take-up speed, 2) the behavior of warp yarn tension has a characteristics of a 1st order system in the case of a constant take-up speed, and 3) variations of warp yarn tension can always occur when take-up speed changes.

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A Study on Economic Effects caused by Improvement of Take-off Minima (이륙최저치 개선에 따른 경제적 효과에 관한 연구)

  • Park, Sohee;Moon, Woochoon;Chang, Manheui
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.22 no.2
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    • pp.48-52
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    • 2014
  • The air traffic are getting a lot of the impact of the weather delays, cancellations, etc. occur frequently. In particular, the phenomenon of global warming, extreme weather events have not experienced one after another and the various damage to users and operators are constantly occurring. In this respect, Take-off Minima of this study are presented need for standardization of ICAO Doc 9365(All Weather Operations). And Incheon International Airport to the introduction of a comprehensive improvement process will be introduced in the future to look forward to take advantage of domestic and international airport officials. In addition, implementation of the Take-off Minima to get direct and indirect economic effects, and will be introduced.