• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.713-714
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• 2012

• 한국분말재료학회지
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• 제13권6호
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• pp.445-449
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• 2006

The experimental data from the central composite design runs were utilized for mathematical models far the drilling characteristics containing linear, quadratic and interactive effects of the parameters such as volume fraction of TiC in the composites, drill speed, feed rate and drill diameter. The models were developed via stepwise selection where the insignificant effects were removed using t-test. The models were subjected to optimization of maximizing drill life and satisfying the other constraints.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.213-214
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• 2006

The CAM software for drill grinding has been developed to save time, reduce cost for tool manufacturing and obtain accuracy of tool. In this paper, the developing software for drill will be presented including calculation and simulation of machining processes using 5-axes CNC grinding machine. The algorithm fer helical flute grinding was applied into calculating NC data. The software will generate NC code for machining by using input data of tool geometry, wheel geometry, wheel setting, machine setting. These NC code files will be used in simulator as input file. The simulator provides some functions for simulating machining processes, inspecting and measuring tool geometry.

• 한국해양공학회지
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• 제34권2호
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• pp.110-119
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• 2020

Explosions and fires on offshore drilling units and process plants, which cause loss of life and environmental damage, have been studied extensively. However, research on drilling units increased only after the 2010 Deepwater Horizon accident in the Gulf of Mexico. A major reason for explosions and fires on a drilling unit is blowout, which is caused by a failure to control the high temperatures and pressures upstream of the offshore underwater well. The area susceptible to explosion and fire due to blowout is the drill floor, which supports the main drilling system. Structural instability and collapse of the drill floor can threaten the structural integrity of the entire unit. This study simulates the behavior of fire subsequent to blowout and assesses the thermal load. A heat transfer structure analysis of the drill floor was carried out using the assessed thermal load, and the risk was noted. In order to maintain the structural integrity of the drill floor, passive fire protection of certain areas was recommended.

• 한국간호교육학회지
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• 제18권3호
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• pp.424-435
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• 2012

Purpose: The purpose of this study was to investigate the disaster experience (accidents, education etc) and the concern for disaster preparedness of college students. Methods: This research design was a descriptive study. Data were collected from November 1, 2011 to December 30, 2011 and analyzed by the SPSS PASW statistics 18.0 program. Results: There were statistical significances in major (p<.050), grade(p<.001), and a completed disaster class(p<.001) between general characteristics and concern for disaster preparedness. The major disaster events that occurred from 2003 to 2010 in Korea were the 2007 Taean oil spill (85.4%), the 2003 Daegu subway fire (82.7%), and the 2008 Sungnyemun fire (62.9%). The possible disaster events in Korea were hurricanes, floods, fires (including wildfire), and the shutdown of communication lines. Subjects learned about cardiopulmonary resuscitation (18.2%), first aid for bleeding and fractures (17.8%), a fire drill (14.3%), and an escape drill for an earthquake (14.0%). They wanted to learn the fire drill (11.33%), the escape drill for an earthquake (9.7%), a war drill (9.0%), a disaster confrontation drill on the subway (8.6%), and a fire and explosion evacuation drill (8.4%). Half of subjects were not prepared with emergency supplies for disasters because they thought that a disaster would not occur. Conclusion: It is necessary to develop the disaster educational programs according to subject's demands in Korea.

• Journal of Biosystems Engineering
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• 제22권4호
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• pp.401-410
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• 1997

Scattering of seeds is one of the problems in the hill- dropping planters with a roller-type metering device. For crops like rice, corns and beans, the hill-dropping is own better for a high yield than the drill planting. The roller type metering device has been used for the drill planters and has many advantages. However, it has a problem of scattering of seeds when they are placed on rows. In this study a method was developed to design the roller type metering device fir the precision hill-droppings. Design parameters were derived to configure completely the geometries of the roller and brush. The method was applied to the design of the metering device of the rice seeding machines. The field test showed that the metering device designed by the method made a better performance of seed placement than that made by the precvious one. The method also can be applied to the design of metering devices for the precise hill-droppings of other crops.

• 실천공학교육논문지
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• 제8권1호
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• pp.23-29
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• 2016

세월호 사건 이후, 불감증이 만연한 우리사회는 안전 교육과 재난대응 훈련에 다시 높은 관심을 가지게 되었다. 하지만 실질적으로 훈련을 하는 데는 비용도 많이 들며, 체험감을 높이는 데에는 한계가 있다. 최근 가상현실의 이점을 활용한 대안들이 콘텐츠 산업분야에서 중요시 되어 여러 콘텐츠들이 개발되고 있다. 본 논문에서는 화재 재난 대응 3D시뮬레이션 설계 시 중점적으로 적용해야 하는 부분을 살펴보고 새로운 설계안을 제안하고 설계과정을 통하여 얻을 수 있는 교육적 효과에 대해 고찰해 본다. 제안하는 시스템 설계하고 구현하기 위해서는 실제적인 3D공간제시를 위한 시스템설계, 재난 대응의 다양한 시나리오 구축, 사용자 효용성을 증대하기 위한 게임요소 적용에는 프로그램능력을 요하는 컴퓨터학과 등과 같은 IT 기반교육과 더불어 모델링 능력을 요하는 미술계 기반교육이 필요하다. 이에 본 연구에서는 제안한 시스템 설계과정을 통하여 얻을 수 있는 융합분야의 교육적 효과에 대해 고찰해 본다.

• 대한기계학회논문집A
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• 제39권6호
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• pp.575-581
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• 2015

드릴비트는 암반에 직접적으로 타격력과 회전력을 전달함으로써 연속적으로 암반을 파쇄, 분쇄하는 천공기의 핵심 구성요소이다. 일정한 속도로 회전하는 동시에 회전축 방향으로 타격하며 암반을 파쇄하기 때문에 암반 파쇄효율을 높이기 위해서는 드릴비트의 배열 최적설계가 필요하다. 그러므로 본 연구에서는 버튼배열 최적화를 수행하기 위한 선행연구로써 버튼배열의 성능을 정량적으로 평가할 수 있는 방법에 대한 연구를 수행하였다. 버튼의 중복타격 면적, 비 타격 면적, 천공편향 모멘트와 같은 평가지표를 활용하여 버튼배열의 파쇄 효율성을 평가하였으며, 더불어 제안된 평가방법을 활용하여 기존 드릴비트 버튼배열의 파쇄 효율성을 검토함으로써 제안한 배열성능 평가방법의 적합성을 확인하였다.

• 한국정밀공학회지
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• 제18권8호
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• pp.107-115
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• 2001

Drilling torque was measured indirectly using the spindle motor current and controlled in real time through feedrate manipulation in a machining center. The PID controller designed in the previous paper was applied to drilling torque control. A series of cutting experiments were performed for various cutting conditions. Experimental results showed that the drilling torque was well regulated at a given reference level by feedrate manipulation in all cutting conditions. The increase in the cutting torque and temperature according to the increase in machining depth was suppressed and the risk of the drill failure and the drill flank wear were reduced remarkably through cutting torque control. Moreover, the suggested cutting torque control system doesn\`t disturb the cutting process and is practical for industrial environment. Therefore, the proposed culling torque control system will contribute to productivity improvement in drilling process.

• 한국소음진동공학회논문집
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• 제15권5호
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• pp.536-541
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• 2005

This paper Presents the performance test of an impact hammer drill in conjunction with the parameter consideration of coefficient of restitution, lubrication and friction, pressure leakage, vibration damper and production quality. Novel measurement setups are innovated in order to get the Parameter data. The measured data are compared with the computational results, and this comparison gives a confidence on the computational model, which can be used for a optimal design of impact hammer drills.