• Korean Journal of Construction Engineering and Management
• /
• v.4 no.1 s.13
• /
• pp.114-121
• /
• 2003

The precise quantity of materials is not yet taken off by the CAD system although it has Influenced in design productivity and automatic estimate. And various estimate systems developed so far deal with the quantity take-off of building members separately, which caused to over-estimate the part of each member. Therefore, the purpose of this paper is to develop algorithms of more precise estimate than that of current estimate by solving boundary conditions of the connection parts of building members, such as column, girder, beam, wall and slab. The algorithms are proposed to take off the quantity of concrete and form work and they will be used for the estimate of building structure more precisely and automatically than ever.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.24 no.3
• /
• pp.48-54
• /
• 2016

This paper proposes a prediction model of air traffic controller's take-off clearance under mixed mode runway operations. The proposed model has its purpose on the better prediction of the air traffic controller's clearance on take-offs of departure aircraft by considering various factors. For this purpose, support vector machine classification algorithm is used for the proposed model. The proposed model is applied to real air traffic operations to demonstrate its performances.

• Korean Journal of Applied Biomechanics
• /
• v.13 no.3
• /
• pp.1-14
• /
• 2003

This study was conducted to investigate the principles and motions for increasing the jumping height of Fosbury Flop. The subjects were three male jumpers who were former Korean national team players. Their jumping motions were analyzed using the DLT method of three-dimensional cinematography. The conclusions were as follows. 1. The horizontal velocity of approach run and decreasing of this velocity during the take off phase were increased as the jumping height was increased. Therefore, in order to increase the jumping height, the horizontal velocity of approachrun should be increased and decreased properly during the take-off phase. The average height of the analyzed Dials was 2.15m. The average horizontal velocity of approachrun was 7.49m/s and decreased to 4.16m/s at the instance of take-off. 2. The vertical velocity of the center of gravity was increased as the ascending height of the center of gravity during the take-off phase was increased. Therefore, the center of gravity at the instant of touch down should be lowered. This could be possible by increasing the length of the last stride and the backward lean angle of the body. The average length of the last stride was 111.1% of the standing height, the average height of the center of gravity was 46.6% of the standing height and the average backward lean angle of the body was 40.3 degrees.

• Ocean Systems Engineering
• /
• v.4 no.1
• /
• pp.63-82
• /
• 2014

Declutching control is applied to a hemispherical wave energy converter with direct linear electric Power-Take-Off systems oscillating in heave direction in both regular and irregular waves. The direct linear Power-Take-Off system can be simplified as a mechanical spring and damper system. Time domain model is applied to dynamics of the hemispherical wave energy converter in both regular and irregular waves. And state space model is used to replace the convolution term in time domain equation of the heave oscillation of the converter due to its inconvenience in analyzing the controlled motion of the converters. The declutching control strategy is conducted by optimal command theory based on Pontryagin's maximum principle to gain the controlled optimum sequence of Power-Take-Off forces. The results show that the wave energy converter with declutching control captures more energy than that without control and the former's amplitude and velocity is relatively larger. However, the amplification ratio of the absorbed power by declutching control is only slightly larger than 1. This may indicate that declutching control method may be inapplicable for oscillating wave energy converters with direct linear Power-Take-Off systems in real random sea state, considering the error of prediction of the wave excitation force.

• Journal of The Korean Digital Architecture Interior Association
• /
• v.12 no.2
• /
• pp.67-76
• /
• 2012

BIM and its quantity take-off widely apply to the construction projects and LCCO2 Assessment using the BIM's quantity take-off function can be tried recently. Because BIM modeling programs such as Revit and ArchiCAD do not provide adequate library for LCCO2 Assessment, quantity take-off data should be conversed and applied to Carbon Emission Coefficient using Excel program or manual work. Therefore, the purpose of this research is 1) to propose the Unit Conversion Systems for Carbon Emission Coefficient, 2) to provide basic library sets for BIM based LCCO2 Assessment method, and 3) to apply 11 material library sets on a apartment unit plan modeling to pursue the CO2 emission evaluation of the material production in the process of LCCO2 Assessment. Research results showed CO2 emission amount of 458.64kgCO2/m2 from the apartment unit plan modeling.

• Communications for Statistical Applications and Methods
• /
• v.20 no.5
• /
• pp.367-376
• /
• 2013

Cut-off sampling is widely used for a highly skewed population like a business survey by discarding a part of the population (the take-nothing stratum). In this paper, we suggest a new composite estimator of the take-nothing stratum total obtained by use of the survey results of the take-nothing stratum and a take-some sub-stratum (a part of take-some stratum) for a more accurate estimate of the population total. Small simulation studies are conducted to compare the performances of known estimators and the new composite estimator suggested in this study. In addition, we use briquette consumption survey data for real data analysis.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.33 no.1
• /
• pp.35-44
• /
• 2020

In the construction industry, there is a growing demand for the accurate calculation of the quantity take-off and construction budget at the design stage, and it is likewise important to grasp changes in the construction budget and quantity take-off if design alterations are made. In addition, lawsuits related to the quantity take-off and cost of construction are frequent; therefore, the calculation of these factors using building information modeling (BIM) has emerged as an alternative. However, existing 2D-based methods are still used more frequently than BIM-based methods for quantity take-offs and construction budgets. This is because of the lack of BIM experience of estimation workers and the absence of a national standard. However, from a designer's point of view, it is necessary to understand the quantity take-off and construction cost based on BIM and accurately create the design according to the budget. In this study, the quantity take-offs of concrete, rebar, and reinforced concrete structures (apartments) in Seoul and Yeongjong were compared with the quantity take-offs based on 2D and BIM methods. From the viewpoint of the designer, we aim to increase the accuracy of BIM-based quantity take-offs.

• Korean Journal of Construction Engineering and Management
• /
• v.13 no.3
• /
• pp.43-55
• /
• 2012

A methodology for BIM Quality Assurance in the construction industry is becoming increasingly an important issue to determine the reliability of BIM. However, the quality assurance of BIM is currently limited to check 3D models, such as clash detection and space layout while verification methods for disciplinary BIM results from structural engineering, mechanical engineering, and estimation do not exist yet. Particularly, in the BIM-based estimation mathematical equations to take off quantities are not clearly exposed so that the results are not quite accepted at practices. With the concept of reliability engineering defined in the manufacturing industry to improve reliability of outcomes of BIM-based quantity take-off, impacting factors that affect reliability of BIM-based quantity take-off were derived. It was found that the factors also include the modeling method and the features of a BIM tool. Therefore, this research aims to propose modeling and verification methods to improve reliability of BIM-based quantity take-off through the pilot test that was performed with commercial BIM tools and IFC-based BIM data.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.10
• /
• pp.5184-5191
• /
• 2013

The automated quantity take off technique using BIM authoring tools has been recently issued, and the studies of this method for the accuracy, efficiency, and the unit computing for the simple volume, area and number have been developed. Meanwhile the main concerns such as the details for the level of modelling, and the costs and time for the calculating BOQ item are still required to study. In this paper, the earth works, drainage works, pavement works, and facility works using BIM authoring tools are designed in 3D, and the applicability of automated quantity take off technique using BIM authoring tools is discussed, respectively. As a result, automated quantity take off are limited in the earth works, drainage works, pavement works, and facility works. But Most items of BOQ can be supported in Re-bar model.

• Korean Journal of Applied Biomechanics
• /
• v.15 no.3
• /
• pp.105-115
• /
• 2005

This study was investigated the kinematic factors of the last approach strides and. take off motion for the skill improving of BKH elite male athlete. 'The subjects chosen for the study were BKH and. KASZCZYK Emillian male athletes who were participated in 2003 Dae-Gu Universiad Games. Three high speed video cameras set in 60frames/s setting were used. for recording from the last approach strides to the apex position. After digitizing motion, the Direct Linear Transformation(DLT) technique was employed to obtain 3-D position coordinates, The kinematic factors of the distance, velocity and angle variable were calculated for Kwon3D 3.1. The following conclusions were drawn; 1. It showed longer stride length, as well as faster horizontal and lateral velocity than the success trial during the approach phase. For consistent of the approach rhythm, it appeared that the subject should a short length for obtain the breaking force by the lower COG during the approach phase. 2. The body lean angle showed a small angle by a high COG during the take-off phase. For obtain the vertical displacement of the COG and a enough space form the bar after take-off, it appeared that the subject should increase the body lean angle. 3. For obtain the vertical force during the takeoff phase, it appeared that the subject should keep straight as possible the knee joint. Therefor, the subject can be obtain a enough breaking force at the approach landing.