• 한국안전학회지
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• 제33권3호
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• pp.1-7
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• 2018

Recently, various engineering approaches have been widely used in the accident investigation field to identify the cause of the accident and to predict damage by accident. Computational analysis is the most commonly used method of accident investigation technique. This technique is mainly used to identify the mechanism of the accident generation and to determine the cause when it is difficult to reproduce the situation at the time of the accident or when it is impossible to perform a reproduction experiment. In this study, The gas explosion analysis for LPG explosion accident generated by defect of the blocking action was performed to determine the accident object, gas leakage amount and predicted the damage caused by the accident using 3D laser scanner and FLACS program. We can quantify the explosive power by LPG gas accident and predict the gas leakage amount, damage by accident and evaluate the stability of the structure through this study. In the future, This method can be widely used in the field of gas safety by improving the reliability and validity of the analysis.

• Journal of Welding and Joining
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• 제34권6호
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• pp.35-41
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• 2016

The experimental study has been performed through residual stress using the Ti6Al4V, investigate the effect of laser shock peening on laser welding process residual stress of Ti6Al4V welds in a reduce safety weld zone. This research evaluated the effects of shock waves from laser shock peening with a pulsed Nd:YAG laser on Ti6Al4V welding specimens, through the analysis of the residual stress of the specimens. The residual stress could be formed by the depth of 1 mm if the proposed method of reducing the residual stress is performed in the optimal condition. The welded structures and products during the production process increase the mechanical property of repeated stress, which could be expected to extend the fatigue life of the structure.

• 대한의용생체공학회:의공학회지
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• 제40권6호
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• pp.230-234
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• 2019

Medical laser equipment using optical energy is used to surgery and treat diseases by destroying and removing tissue. Domestic laser equipment has been used steadily in the skin and cosmetics sectors and has been changed to radiate high-power energy in a wide range to shorten patient treatment time. However, side effects such as burns and damage of normal tissues occurred. To solve this problem, techniques for detecting lesions using an imaging device and selectively radiating the laser have been developed. In this study, we proposed an evaluation method to evaluate the safety and performance of target detection accuracy, laser irradiation accuracy and motion protection device technology derived from product analysis and investigation. Finally, the validity of the evaluation method was evaluated by evaluating the imaging device based laser equipment as the proposed evaluation method.

• 한국항공우주학회지
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• 제49권9호
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• pp.771-780
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• 2021

우주물체 레이저 추적(DLR : space Debris Laser Ranging) 시스템은 인공위성까지의 거리를 측정하는 인공위성 레이저 추적(SLR : Satellite Laser Ranging) 시스템의 확장형이라고 할 수 있다. 레이저를 발사하여 수신하는 광자 왕복하는 시간을 측정하여 궤도 결정하는 시스템이다. 거리 정밀도는 mm급 단위로 측정 가능하고 현존하는 시스템 중 가장 정밀한 시스템이다. 현재 한국천문연구원은 인공위성 레이저 추적 시스템을 세종 및 거창에 구축하였고, 나로호 과학위성, 다목적 실용위성 5호의 정밀궤도를 검증하기 위해 SLR 데이터를 활용하였다. 최근 몇 년간 우주쓰레기의 추락 또는 충돌로 인해 자국의 위성이 위협받고 있고, 이는 안보적인 측면에서 자국 우주자산 보호, 국민의 안전을 보호하기 위해 우주물체 레이저 추적이 지대한 관심을 받고 있다. 본 논문에서는 인공위성 레이 추적, 우주물체 레이저 추적을 고려한 다목적형 레이저 추적 시스템의 시스템 설계를 위하여 1.5m 급 주경을 적용하였다. 그리고 주요 구성품의 성능(레이저 파장, 레이저 출력) 등을 고려하여 링크버짓 분석을 통해 시스템 예비 성능 분석을 수행하였다.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2008년도 정기학술발표대회 논문집
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• pp.364-367
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• 2008

현재 건설 산업에서 나타나고 있는 숙련공 부족 현상, 기술자의 고령화 문제, 안전상의 문제 등을 해결하기 위한 대안으로 자동화 건설기계들의 개발 요구가 점점 높아지고 있다. 특히 토공작업은 매우 기계 의존적인 작업이기 때문에 자동화된 굴삭기 개발과 관련된 연구가 많이 이루어지고 있다. 자동화 굴삭 시스템을 개발하는 데 있어서는 안전을 확보하는 것이 중요하다. 그래서 본 연구의 주제는 자동화 굴삭 시스템의 안전성을 어떻게 향상시키는 기술을 개발하는 데에 있다. 또한 본 연구의 목적은 굴삭 작업에 있어서 자동화 굴삭기의 객체 탐지를 위한 알고리즘을 개발하여 소프트웨어에 적용하는 것이다. 선행연구를 통해 여러 가지 센싱 기술들의 성능에 대해 조사 및 분석을 실시하였으며, 최적의 레이저 센서를 선정하여 성능의 적정성을 입증하기 위한 실험을 실시하였다. 사용자 인터페이스 프로그램을 위한 객체탐지 알고리즘을 개발하였고, 이는 자동화 굴삭 시스템의 안전관리 시스템 개발의 원천기술로써 활용될 수 있을 것이다.

• 한국지리정보학회지
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• 제9권3호
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• pp.207-218
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• 2006

도로교통 안전진단에 있어 도로의 형상분류를 통한 도로 선형 및 횡단면 데이터의 추출은 매우 중요한 작업이다. 기존의 조사원에 의한 도로안전진단은 많은 시간과 비용이 요구되는 반면 도로안전진단을 위한 다양한 정보를 제공하지 못한다는 단점이 있다. 따라서, 레이저 스캐닝 장치를 장착한 차량측량시스템을 이용, 수치사진측량시스템 기술을 활용하여 자동으로 도로형상을 분류하고, 도로 선형 및 횡단면 데이터를 추출하는 방안이 필요하다. 본 논문에서는 이를 위해 모바일 레이저 스캐닝 데이터를 취득하여 처리하고, 이를 통해 도로 선형 및 횡단면 데이터를 추출할 수 있는 방안을 제시하고, GPS-VAN 을 이용 취득된 모바일 레이저 스캐닝 데이터를 처리, 도로 선형 및 횡단면 데이터를 추출하는 연구를 진행하였다.

• 소성∙가공
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• 제24권5호
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• pp.354-360
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• 2015

AHSS (Advanced High Strength Steels) has been increasingly employed by global automotive OEMs in order to satisfy strengthened regulations and reduce weight for fuel efficiency. Hot stamping using boron steels in AHSS increases not only formability but also strength. The typical hot-stamped automotive part is the center pillar that is critical for vehicle side impact. However, the hot-stamped part can be risky for the passenger safety caused by brittle fracture under a vehicle collision. The high power diode laser is suitable for the heat treatment giving AHSS increased elongation that prevents brittle fracture in car crash. Therefore, local softening by laser heat treatment for energy absorption area on the hot-stamped part improves crash-worthiness.

• Journal of Periodontal and Implant Science
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• 제43권6호
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• pp.262-268
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• 2013

The use of dental implants has become a mainstay of rehabilitative and restorative dentistry. With an impressive clinical success rate, there remain a few minor clinical issues with the use of implants such as peri-implant mucositis and peri-implantitis. The use of laser technology with implants has a fascinating breadth of applications, beginning from their precision manufacturing to clinical uses for surgical site preparation, reducing pain and inflammation, and promoting osseointegration and tissue regeneration. This latter aspect is the focus of this review, which outlines various studies of implants and laser therapy in animal models. The use of low level light therapy or photobiomodulation has demonstrated its efficacy in these studies. Besides more research studies to understand its molecular mechanisms, significant efforts are needed to standardize the clinical dosing and delivery protocols for laser therapy to ensure the maximal efficacy and safety of this potent clinical tool for photobiomodulation.

• 대한의용생체공학회:의공학회지
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• 제35권3호
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• pp.62-67
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• 2014

The purpose of the study was to identify the effect of laser parameters on photocoagulation to maximize safety and efficacy during varicose vein treatment. CW and pulsed modes at 1470 nm were initially compared as a function of power on bovine liver tissue. In the pulsed mode, various parameters including repetition rate, duty cycle, and irradiation time were compared to evaluate tissue response during thermal treatment. The results demonstrated that CW and pulsed modes yielded almost similar coagulation development possibly due to shorter irradiation time of 5 sec. Regardless of laser mode, both repetition rate and duty cycle presented constant coagulation rate whereas longer irradiation time facilitated coagulation process.

• 센서학회지
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• 제30권6호
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• pp.420-428
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• 2021

In this study, linearized sweeping of a wavelength sweeping laser was realized. This technique was used to measure the strain on a fiber Bragg grating(FBG) sensor. For linear sweeping, PID control over the wavelength difference between linear and nonlinear sweeping was employed. The performance test showed that linear sweeping with a 46 nm range and a 1 kHz frequency held up well with a 99.5 % decrement in nonlinearity after the 120th feedback. When attached to a strain gage, the FBG sensor registered strain that matched the data sheet within a difference of 4.5[με]. Altogether, linear sweeping can play a leading role in monitoring a safety of large SOC structures as well as in other wavelength sweeping laser related fields.