• 기술사
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• 제16권3호
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• pp.41-53
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• 1983

The Dangri Crushed Stone Quarry is located in Dangridong, Busan City, and around the estuary of the Nagdong River. The quarry is considered to be a very promised one in the urban area from the standpoints of the assessment of the aggregate rank, the environmental impacts and the transportation distance. The crushed stones for aggregate of the quarry marks the higher rank in the gravity, the absorption ratio, the abrasion ratio, and the stability in comparison with the JISA 5005. The basement vibrations of the residential section in the vicinity of the quarry, which are arised by the millisecond blasting at the quarry site using the gelatin dynamites less than 39kg in weight, are measured to assess the vibration nuisance. The values of acceleration and the magnitudes are less than eight gals and O on the Richter scale respectively, the vibration nuisance thus can be ignored in such scales of the experiments. The traffic vibrations of the residential section are slightly susceptible. In the experiments, the traffic vibrations appears to be sensibler to the basement than the explosion vibration. The explosion noises in the experiments are not checked not only on the RION Sound Level Meter but also to our ears. The values of traffic noises also are in the safety values of the noise nuisance. The crush dust suspends in the air toward the upper valley in the opposite side of the residential area because of the influences of the sea breeze and the valley wind in the daytime, and the monsoon and the topographic disposition. the dust nuisance thus would not be remained in problem. The quarry is operated in the daytime only. The traffic dust in the residential area will be reduced by the faultless pavement and the careful driving. The elaborate survey on the ridges and peaks surrounded the quarry is recommended to prevent in advance the accidents of the rock slide. Moreover, it is required to make an advisory committee to develop the industry and to save the techniques. The most important matter is the accomodation between the attitude of the enterprising man for the social responsibility to the public nuisance and the cooperative spirit of the inhabitants for the industry.

• 대한안전경영과학회지
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• 제6권2호
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• pp.251-262
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• 2004

There is boner process of stone manufacturing to become quality down of stone to consolidated micro crack appearance of stone surface and biotite by fire that is to be route process in stone surface by flame of LPG. And then, it is develop that stone surface process equipment by automation for the work method of boner process can be substitute work method by shotball blasting. To developement of equipment, There is to be down noise and dust. Acording to remove calamity growth hazardous substance in the work environment, there is to solve workplace avoidance factor. We have taken Taguchi's parameter design approch, specifically orthogonal array, and determined the optimal levels of stone surface through analysis of the experimental results using SIN ratio.

• 화약ㆍ발파
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• 제29권2호
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• pp.59-66
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• 2011

자연적, 기술적, 생물학적 재해에 의해 유발된 다양한 리스크가 조직의 업무연속성에 위협을 미친다. 업무연속성은 모든 조직에 가장 중요한 과제로써 그것을 적절히 관리하는 것은 조직의 성패를 가르게 된다. 업무연속성계획(BCP)은 업무연속성을 담보할 수 있는 관리 절차로 정의될 수 있다. BCP는 리스크관리, 상시운영계획, 재난대응/복구, 훈련/학습, 위기 전달 등을 포함한다. 이중에서 리스크관리는 리스크확인, 분석, 평가 처리를 하기 위한 체계적 방법으로 리스크평가는 리스크확인, 분석, 평가로 구성된다. 리스크평가는 BCP를 계획하기 위한 첫 번째 단계이다. 본 연구에서는 하수관거 매설 공사에 대해서 리스크평가를 수행하였다. 리스크평가 과정을 통해 건설 공사에 위협을 주는 18개의 리스크를 확인하였고 이들에 대한 리스크 수준 분석을 통해 대책이 필요한 가장 상위 수준의 리스크로는 '굴착면의 붕괴', '지중매설물 파손', '소음 및 먼지날림', '원자재값 상승'으로 나타났다.

• 화약ㆍ발파
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• 제30권1호
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• pp.17-28
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• 2012

도심지에서의 구조물 해체공사는 소음, 진동 및 분진을 발생시켜 주변에 불편을 끼치는 경우가 많아 다양한 제어방안이 고안되어 사용되고 있다. 그 중에서 화약을 이용해 순간적으로 구조물을 붕괴, 전도시키는 발파해체공법은 시공 중 먼지, 소음 등으로 주변피해를 최소화시키고, 공사기간을 단축해 공사비도 절감되며, 작업자에 대한 안전의 확보가 가능한 친환경적인 공법으로 시공사례가 증가하고 있다. 한편, 도심지에 위치한 구 성남시청 구조물은 기둥과 보로 이루어진 철근콘크리트 라멘구조로 여러 개의 높이가 다른 건물들이 연결통로를 통해 서로 이어져 있는 복합구조물로써 공기단축과 주변 주민에 대한 피해를 최소화하고자 발파해체공법을 적용하여 시공하였다.

• 청정기술
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• 제4권2호
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• pp.41-53
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• 1998

열처리시 대부분 연소로의 경우는 대기중에서 열처리되기 때문에 표면에 산화피막이 형성된다. 그러므로 이의 제거를 위해 숏블라스트(Shot blasting) 같은 연마와 산세공정이 추가되므로 공정소요 시간이 오래 걸리고 연마분진으로 인한 작업장의 환경악화는 물론 제품의 형상이 복잡하거나, 강관의 내면은 처리가 더욱 어려워진다. 그러므로 본 연구에서는 연소로 내부에 고온 내구성을 지닌 강재로 내부로를 제작하고 내부 분위기를 불활성분위기로 조절하여 산화피막의 형성을 저감시키기 위하여 연구하였다. 전기로에서 실험된 시편의 SEM, EPMA, EDX의 분석결과 산화피막이 저감됨을 알 수 있었고, 또한 진공로와의 처리품질 비교에서도 진공로와 유사한 광휘성을 나타내었다. 연구결과 개선공정을 적용하기 위해 내부로는 원통형에 재질은 SBB410으로 제작하고 분위기 가스가 유입되는 가스관로는 STS310으로 하부에서 유입시키는 방식이 가장 효율적일 것으로 도출되었다. 기적용된 사업장의 절감효과를 적용한 경제성 평가에서 연간 약 4천만원 이상의 절감효과가 기대되고, 청정기술적 효과로는 열처리 이후 제품의 구조상 제거되지 못하는 산화피막에 대한 대책 수립 및 산화피막 폐기물발생 저감, 그리고 공정단축과 작업환경의 개선효과를 볼 수 있다.

• 산업경영시스템학회지
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• 제44권3호
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• pp.39-49
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• 2021

The Korean Air-Force aircraft maintenance depot paints the exterior of various aircraft, including high-tech fighters. Aircraft exterior painting is a maintenance process for long-term life management by preventing damage to the aircraft surface due to corrosion. The de-painting process is essential to ensure the quality of aircraft exterior paints. However, because the Korean Air-Force's de-painting process is currently done with sanding or Plastic Media Blasting (PMB) method, it is exposed to harmful dust and harmful compounds and consumes a lot of manpower. This study compares the de-painting process currently applied by the ROK Air-Force and the more improved process of the US Air Force, and performs economic analysis for the introduction of advanced equipment. It aims to provide information that can determine the optimal time to introduce new facilities through Cost-Volume-Profit (CVP) analysis. As a result of the analysis, it was confirmed that the sanding method had the most economical efficiency up to 2 units per year, the PMB method from 3 to 21 units, and the laser method from 22 units or more. In addition, in a situation where the amount of de-painting work is expected to increase significantly due to the increase in fighters in future, BEP analysis was conducted on the expansion of the existing PMB method and the introduction of a new laser method. As a result of the analysis, it was confirmed that it is more economical to introduce the laser method when the amount of work exceeds the PMB work capacity(18 units per year). The paper would helpful to improve the productivity and quality of the Korean Air Force Aircraft maintenance depot through timely changes of facilities in the workplace in preparation for expansion.

• International Journal of Ocean System Engineering
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• 제2권3호
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• pp.185-194
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• 2012

A Macroscopic combination of two or more distinct materials is commonly referred to as a "Composite Material", having been designed mechanically and chemically superior in function and characteristic than its individual constituent materials. Composite materials are used not only for aerospace and military, but also heavily used in boat/ship building and general composite industries which we are seeing increasingly more. Regardless of the various applications for composite materials, the industry is still limited and requires better fabrication technology and methodology in order to expand and grow. An example of this is that the majority of fabrication facilities nearby still use an antiquated wet lay-up process where fabrication still requires manual hand labor in a 3D environment impeding productivity of composite product design advancement. As an expert in the advanced composites field, I have developed fabrication skills with the use of machinery based on my past composite experience. In autumn 2011, the Korea government confirmed to fund my project. It is the development of a composite sanding machine. I began development of this semi-robotic prototype beginning in 2009. It has possibilities of replacing or augmenting the exhaustive and difficult jobs performed by human hands, such as sanding, grinding, blasting, and polishing in most often, very awkward conditions, and is also will boost productivity, improve surface quality, cut abrasive costs, eliminate vibration injuries, and protect workers from exposure to dust and airborne contamination. Ease of control and operation of the equipment in or outside of the sanding room is a key benefit to end-users. It will prove to be much more economical than normal robotics and minimize errors that commonly occur in factories. The key components and their technologies are a 360 degree rotational shoulder and a wrist that is controlled under PLC controller and joystick manual mode. Development on both of the key modules is complete and are now operational. The Korean government fund boosted my development and I expect to complete full scale development no later than 3rd quarter 2012. Even with the advantages of composite materials, there is still the need to repair or to maintain composite products with a higher level of technology. I have learned many composite repair skills on composite airframe since many composite fabrication skills including repair, requires training for non aerospace applications. The wind energy market is now requiring much larger blades in order to generate more electrical energy for wind farms. One single blade is commonly 50 meters or longer now. When a wind blade becomes damaged from external forces, on-site repair is required on the columns even under strong wind and freezing temperature conditions. In order to correctly obtain polymerization, the repair must be performed on the damaged area within a very limited time. The use of pre-impregnated glass fabric and heating silicone pad and a hot bonder acting precise heating control are surely required.