• Industry Promotion Research
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• v.4 no.2
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• pp.1-8
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• 2019

This research is a technology for cutting the insulation of the busbar (busbar) installed in the distribution panel or switchboard, the results of the study, first, the cutting unit and frame of the cutting unit including a housing attached to the upper and lower cutters, respectively Busbar coating laser cutting machine is installed on the top, characterized by consisting of a stopper for adjusting the coating cutting distance of the busbar. Second, the frame is installed with the guide bar in the longitudinal direction at the top so as to be located at the rear side end of the table, the post is installed vertically at the front and rear at the upper middle part, respectively, and cut to the table at the outer side of the front post. It is characterized by the formation of holes. Third, the supporter is fixedly installed on the upper part of the guide bar arranged in the frame, and is characterized by consisting of a cylinder and a support plate. The meaning of this study is to prevent the safety accidents of workers, to improve the efficiency of cutting work, and to prevent the occurrence of scratches on the surface of the busbar.

• Land and Housing Review
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• v.2 no.4
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• pp.553-558
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• 2011

Existing method protruding strands that are embedded in PHC pile to connect pile head and foundation slab shows poor constructibility. As this causes crack and damage in pile head and casualties often occurs in construction site during the work, alternative method called one-cutting method, in which pile above the ground surface and strands embedded in pile are completely cut and pile head is reinforced with rebar for connection with foundation slab, is currently adopted. However, the capacity of details for these methods are not mechanically proved. In this study, in order to suggest proper details of reinforcement for one-cutting method, failures due to lack of shear resistance between infilled concrete and PHC pile are analyzed through experiments and embedded depth with infilled concrete inside PHC pile is suggested. Assuming that slip failure strength is 0.4MPa, which is obtained from experiment conservatively, to have rebar yielded before slip failure, minimum depth of infilled concrete for PHC 450 and PHC 500, need to be 600mm above, and for PHC 600, 1,000mm above.

• Korean Journal of Construction Engineering and Management
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• v.21 no.2
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• pp.98-106
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• 2020

Conventional method of PHC pile head cutting work has several challenges with regard to safety, convenience, productivity, and quality. To address such problems, a prototype of the all-in-one attachment-based PHC pile cutting robot is developed(Yeom, 2018). The Primary objective of this study are to develop a final prototype of all-in-one attachment-based PHC pile cutting robot and to analyze technical feasibility and field applicability of final prototype. According to the technical feasibility and field applicability analysis result, at least 74.2% of the respondents are selected positive answer about technical feasibility of the final prototype, at least 66.6% of the respondents are selected positive answer about field applicability of the final prototype. It is expected that when deployed onsite, the final prototype can not only increase the practical use but also improvement the work safety and productivity of work at the PHC pile head cutting job site.

• Korean Journal of Construction Engineering and Management
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• v.19 no.2
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• pp.117-125
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• 2018

The primary objectives of this study are to develop a detail design of automated PHC pile head cutting machine and structural stability analysis of detail design that improves the conventional head cutting work in safety, quality, and productivity. For this, the following research works are conducted sequentially; 1)literature review and field study, 2)expert survey and interview, 3)selection of core technology using AHP analysis, 4)deduction of detail design 5) verification of structural stability. As an outcome, it is analyzed that gripper and gripper bearing shaft are structurally stable. Their maximum stresses are shown as 15.93%, 10.58% compared to their yield strength respectively. The results of detail design and structural stability analysis in this study will be utilized for the actual development of the automated PHC pile cutting machine prototype.

• 프린팅코리아
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• v.9 no.9
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• pp.116-117
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• 2010

디젠(대표 이길헌)은 지난해 국내에 처음으로 공급한 'Versa UV LEC-300'이 고객에게 새로운 수익원으로 자리매김하면서 고부가가치를 창출하고 있다고 밝혔다. 새로운 시장을 창출한 주인공은 서울 충무로에 위치한 정우프린팅(대표 권오성)이다. 지난해 UV 프린팅과 커팅이 동시에 가능한 'Versa UV LEC-300'을 국내에서 처음으로 도입했던 정우프린팅은 이 장비를 이용, 화이트잉크와 투명 광택잉크로 질감과 입체감 표현까지 표현하면서 고객들에게 고품질 고부가가치 출력시장에 만족을 주고 있어 1년 365일 가동을 쉬는 날이 없을 정도로 고객의 주문을 받고 있다.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2011.10a
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• pp.161-162
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• 2011

유압동력사용 전제하에, 기계식탈피복을 고려하지 않을 때는 전단방식이 가장 유리함을 알 수 있다. 절단방식은 전단방식에 비해서 낮은 생산성이 단점이나, 높은 원형도의 연료봉 절단면이 요구되거나, 비산에 의한 칩 분리, 쿨링(cooling) 장치를 보완하면 절단방식이 유리하다. 또한 수평식 슬릿장치는 커팅 블레이드의 낮은 내구성으로 생산성이 낮은 것이 단점이나 내구성이 강한 공구를 사용하여 처리 속도를 향상한다는 전제에서 실험적 검증의 확보, 그리고 별도의 복잡한 펠릿/헐 분리장치를 보완하면 수평식 슬릿 방식이 유리하다.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.2
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• pp.37-44
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• 2019

The primary objective of this study is to develop a prototype of all-in-one attachment-based PHC pile head cutting robot that improves the conventional work in safety, productivity, and quality. For this, the following research works are conducted sequentially; 1)literature review, 2)development of an all-in-one attachment-based PHC pile head cutting robot prototype, 3)performance evaluation of each device, 4)economic analysis of an automated method. As a result, PHC pile cutting level sensing device, PHC pile cutting device, PHC pile handling device are developed. Futhermore, working process of an automated method is developed based on result of performance evaluation. According to the economic analysis result, the cost of the automated method was 21.37% less than that of the conventional method, and the economic efficiency was also superior(ROR 215.44%, Break-even Point 5.52month). It is expected that conclusions for future improvements are used in the development of the all-in-one attachment-based PHC pile head cutting robot to practical use.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.3
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• pp.292-299
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• 2012

This paper proposes the design of circularly polarized multi band antenna for a non-linear junction detector (NLJD) system. In order to design for broad bandwidth, the CPW (Co-Planar Waveguide) feeding method is considered in this design. In order to realize the circular polarization, the axial ratio was controlled by inserting a $45^{\circ}$ inclined slot on radiating element and by cutting an edge of the radiating patch. Measurement results of return loss, bandwidth, axial ratio, polarization pattern and gain are agreed well with their simulation results in interested frequency band at 2.4~ 2.44 GHz, 4.84~4.92 GHz, and 7.28~7.32 GHz.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.80-80
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• 2011

세계 기후 변화와 불안정한 유가 변화에 대응하고 국내산업의 저탄소 녹색성장을 위해 신재생에너지 개발이 활발하게 이루어지고 있다. 해양에너지 중에서 조류발전은 대규모 댐을 건설할 필요가 없어 비용이 적게 소요되고 특히 날씨 변화나 계절에 관계가 없고, 발전량이 예측 가능하므로 신뢰성 있는 에너지원으로 적용이 가능하다. 조류발전기 블레이드에 폴리머계 복합재료와 스테인리스강이 대부분인데, 이 재료는 특정 회사에서만 제작 가능하며, 충격에 약하고, 균열전파 속도가 빠르며, 대단히 고가이며, 수입에 의존하고 있는 실정이다. 이러한 조류발전에 사용되는 블레이드는 가혹한 부식, 캐비테이션 그리고 침식환경에 노출되어 있어 내구성이 우수한 제품개발이 대단히 중요하며, 조류발전 블레이드를 동합금으로 제작시, 내식성이 뛰어나며 구리의 특성상 해양생물 서식을 방지할 수 있고, 내캐비테이션 특성, 내구성, 가공성 및 유지보수가 용이한 장점이 있다. 이러한 동합금에 WC-27NiCr와 WC-10Co4Cr를 초고속 화염용사(HVOF)를 이용하여 코팅층의 캐비테이션 특성 및 전기화학적 거동을 연구하였다. 본 연구에서는 조류발전용 블레이드의 재료로 사용하려는 동합금에 WC-27NiCr와 WC-10Co4Cr이 용사코팅된 시험편을 사용하였다. 다채널 부식시험기인 WonA-tech WMPG-1000을 이용하여, 자연전위를 측정하였으며, 분극실험은 자체 제작한 홀더를 사용하여 $0.3318cm^2$를 노출 시켜 실험하였다. 기준전극은 은/염화은 전극을, 대극은 백금 전극을 사용하였다. 양분극과 음분극 실험을 통해 개로전위에서의 부식거동을 확인하였고, 정전위 실험도 실시하였다. 실험 종료 후 3D현미경 및 전자주사현미경(SEM)을 사용하여 코팅층 표면의 손상거동을 관찰하였다. 캐비테이션 실험은 ASTM-G32 규정에 의거하여 압전효과를 용한 진동발생 장치(RB 111-CE)를 사용하였다. 수조는 전기화학적 부식의 영향을 고려하여 아크릴로 제작하였고, 시험편은 실험장비에 맞게 파인커팅머신을 이용하여 $20mm{\times}20mm$로 절단하여 사용하였으며 혼과 대향하도록 하여 1mm 간격을 두어 실험하였다. 실험 실시 전, 미소전자저울을 사용하여 무게감소량을 측정하였으며 표면관찰을 통하여 캐비테이션 거동을 관찰하였다.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.2
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• pp.453-467
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• 2018

The excavation performance and the cutting tool wear prediction of shield TBM are very important issues for design and construction in TBM tunneling. For hard-rock TBMs, CSM and NTNU model have been widely used for prediction of disc cutter wear and penetration rate. But in case of soft-ground TBMs, the wear evaluation and the excavation performance have not been studied in details due to the complexity of the ground behavior and therefore few testing methods have been proposed. In this study, a new soil abrasion and penetration tester (SAPT) that simulates EPB TBM excavation process is introduced which overcomes the drawbacks of the previously developed soil abrasivity testers. Parametric tests for penetration rate, foam mixing ratio, foam concentration were conducted to evaluate influential parameters affecting TBM excavation and also ripper wear was measured in laboratory. The results of artificial soil specimen composed of 70% illite and 30% silica sand showed TBM additives such as foam play a key role in terms of excavation and tool wear.