• Korean Journal of Construction Engineering and Management
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• v.24 no.5
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• pp.52-62
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• 2023

The objective of this study is to propose an automated algorithm for precise cutting length of slab rebar complying with regulations such as anchorage length, standard hooks, and lapping length. This algorithm aims to improve the traditional manual quantity take-off process typically outsourced by external contractors. By providing accurate rebar quantity data at BBS(Bar Bending Schedule) level from the bidding phase, uncertainty in quantity take-off can be eliminated and reliance on out-sourcing reduced. In addition, the algorithm allows for early determination of precise quantities, enabling construction firms to preapre competitive and optimized bids, leading to increased profit margins during contract negotiations. The proposed algorithm not only streamlines redundant tasks across various processes, including estimating, budgeting, and BBS generation but also offers flexibility in handling post-contract structural drawing changes. In particular, the proposed algorithm, when combined with BIM, can solve the technical problems of using BIM in the early phases of construction, and the algorithm's formulas and shape codes that built as REVIT-based family files, can help saving time and manpower.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.1
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• pp.89-98
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• 2012

A steel wire-integrated deck plate that welds integrated triangle truss steel wires on a galvanized steel sheet is developed to reduce construction costs of slabs or formworks such as shores and supports, and it is already widely applied in many construction fields. In this research, experimental tests for 14 full scale specimens, which are in the same field conditions, are conducted on several parameters such as the diameter of top, bottom and lattice steel wire, cutting methods of ends. According to the result, changes in final destruction types of the test bodies and cutting methods of ends didn't affect structural performance of test specimens, and for a 4.0m-span test specimen, there was no big problems in using bottom bar D7 or D8.

• Journal of Korean Society of Forest Science
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• v.38 no.1
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• pp.27-32
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• 1978

The diurnal pattern of leaf water potential in cuttings by Dye Method was as follows: 1. Diurnal pattern of leaf water potential (${\psi}_l$) in Viburnum Awabuki K. Koch and Daphne odora Thunb. was shown the pattern of the curves without mutual relation with soil classes when soil water potential (${\psi}_s$) was 0 bar. When ${\psi}_s$ was above -0.01 bar, the cuttings in the loamy sand (L.S.) was shown by the maximum values than that in sandy clay (S.C.) by about -1 bar gap (Fig. 1). 2. The diurnal changes of ${\psi}_l$ was shown the most high from two to eight O'clock in the morning, the maximum value was -3 bars when ${\psi}_s$ was above -0.01 to -0.02 bar, and was -4 bars below -0.03 bar. The diurnal the lowest values of ${\psi}_l$ showed -20 to -22 bars from one to two O'clock in the afternoon. In the fifteenth day after cutting V.A., the staying time in the diurnal maximum values of ${\psi}_l$ is about half in comparison with it in the fifth day. The curves of recovery of water stress (Fig. 1), the former reached to the diurnal maximum values -1 to -2 bars lately every hours comparing with it of the latter. The general diurnal pattern of ${\psi}_l$ was most clearly related to change with air temperature and the relative humitidy. 3. Comparing the treatment block by IAA 50 ppm with controlled block in fifteenth day after V.A. cuttings, in case of treatment reached to maximum values -2 to -3 bars lately as shown Fig. 2., and also staying times was only half in comparison with controlled block. 4. The cuttings 4 leafs was much rootings than 2 leafs in V.A. (Table. 1), and the former reached maximum value -2 to -3 bars lately every hours comparing with the latter. 5. In case of Buxus microphylla var. Koreana as shown Fig. 3., comparing the pattern curves of in the cuttings 8 leafs with 4 leafs, the former reached to maximum values -2 to -3 bars lately in comparison with the latter, but reffering to the amount of rooting (Table. 2), the former is less than the latter.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2002.11a
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• pp.133-138
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• 2002

Rebar work takes up big proportion in a construction work. The current process of purchasing, cutting and election, and working of rebar induces a lot of loss in rebar. This study is focused on analyzing the problem and the present condition of the process from the calculating of rebar quantifies to the actual constructional stage through surveying those who have experience in the estimation department, or the construction site of a domestic construction company. Many reform measures such as diversification of standard(i.e., 8-meter)bar, calculation of rebar quantities and construction according to the rebar election drawing, expansion of accuracy in layout plan, thoroughness in examination of layout plan in advance, utilization of the worked material, systemization of rebar control(management), and a shift in attitude of the field(site) manager were proposed as the result of the survey.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.323-326
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• 1997

Conventional robots actuated by motors with the speed reducer such as harmonic drive had weakness in delivering loads, pressing, grinding, and cutting jobs. To overcome this, the developer a new type of robot actuated by the ball screw. The robot is an articulated shape, which is composed of four axes. The base axis is actuated similarly with conventional robot, but the others are actuated by four bars mechanism composed of the ball screw. We setup the dynamics model of the robot. The robot has parameter uncertainties and nonlinearlity due to the ball screw actuator. To coordinate the robot, we applied sliding-mode control.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.348-352
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• 1992

At present, the manufacturing industry is in a process of great change of circumstances like meeting demands to involve a great variety of types and shorter product life and thus more flexible manufacturing. These changes cause the larger number of different tools and frequent tool changes, which lead to the considerable losses in productive time and the high amount of capital tied up in the tool area. In our country, for the most part, the individual tool are still being presetted according to a data sheet and the measured values are entered, output in a list manually or via punched tapes. This usually takes a considerable amount time and lead to a high error rate. This paper describes a computer controlled tool data management system combined with the bar code tool identification labeled on cutting tools.

• Proceedings of the Korean Society of Computer Information Conference
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• 2008.06a
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• pp.211-216
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• 2008

이 논문은 철근 가공 산업 현장에서 스프레드쉬트에 의해 수작업으로 행하던 절단 작업의 계획 수립을 자동화된 시스템에 의해 최적의 절단 계획을 생성하도록 하는 소프트웨어의 개발을 다룬다. 이를 위하여, 먼저 시스템의 데이터 표현과 최적 문제 풀이를 위한 자동 계획 알고리듬의 설계가 요구된다. 이것은 다중 규격의 1차원 자재 절단 문제를 푸는 것으로, 동적계획법에 근거하여 자재 절단 문제를 재구성하고, 유한 범위의 조합 열에서도 근사 최적의 해를 찾을 수 있는 탐색 기법을 사용한 자재 절단 계획 알고리듬을 사용하였다. 그리고, 자동화된 철근 가공 산업용 소프트웨어는 작업 환경에 맞게 사용이 편리한 그래픽 화면과 사용자 인터페이스가 요구되는데, 공개 소프트웨어를 활용한 GUI 라이브러리 툴킷인 GTK+를 활용하여 이를 구현하였다.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1102-1103
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• 2006

The pretreatment for substrate was carried out in change of gun pressure of $0.5\sim3.5$ bar using wet blasting. The size of $Al_2O_3$ powder was about $50{\sim}150{\mu}m$. As the results, the surface roughness of cemented carbide substrate was improved with increment of gun pressure of wet blasting. A new surface layer was formed and Co particles were uniformly distributed over the entire surface after pretreatment. The adhesion of the pretreated substrate in same PVD-TiAlN film was improved and in approximately $Ra=90\sim120\;nm$ shown the best adhesion value.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.1050-1051
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• 2013

조선업종은 숙련공의 감소와 노동력 부족을 해결하기 위해 자동화와 기계화가 필요하다. 특히 조선용 핸드레일 제조공정은 표준화된 타 분야와 달리 자동화가 낙후되어 있다. 본 연구에서는 조선용 핸드레일 제작에 사용할 수 있는 평철 가공자동화시스템을 설계하였다. 시스템의 기구부는 절단공정의 효율성, 생산성, 안정성 등을 고려하여 설계하였고, CATIA 와 ANSYS를 사용하여 구조물의 안정성을 확인하였다. 시스템 제어부는 개방성과 확장성을 제공하는 PCNC 콘트롤러를 사용하였고, 터치스크린 방식의 화면 조작을 통해 시스템의 제어 및 모니터링을 할 수 있도록 구축하였다.

• Journal of the Korea Society for Simulation
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• v.33 no.3
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• pp.27-35
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• 2024

Generally, an Linear Shaped Charge(LSC) is used for cutting a mechanical structure of various weapon systems. The penetration performance of an LSC is subjected to the type of explosive, the amount of explosive charge per unit length, the type of sheath material, stand-off distance from the target etc. In addition, the non-uniform cross-sectional shape originated from the manufacturing process may affect penetration performance. In this study, in order to analyze the penetration performance of an LSC, Computed Tomography(CT) images of its internal shape were taken and penetration experiments of the LSC were performed on a square metal bar. The experimental results showed that the penetration depths varied depending on the longitudinal position of the LSC, and at some locations, did not meet the required cutting performance. The LSC used in the experiment was manufactured to be able to cut a 4 mm plate, but in the results of the penetration performance experiment, there were many locations where the penetration depth was less than 4 mm. To find this reason, the penetration performance that did not meet the required cutting performance was simulated through AUTODYN based numerical analysis to confirm whether the LSC is cut in the plate. Through numerical analysis, it was confirmed that the penetration performance of an LSC varies depending on the thickness of the incision target due to the distribution of stress.