• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.11a
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• pp.110-115
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• 1999

The emergence of portable information terminals in work and living environments is accelerating introduction of wireless digital links and local-area networks(LANs). Transmission using infrared radiation recently become a viable option. As a transmission medium, infrared offers several advantage over radio. The infrared spectral region offers a virtually unlimited bandwidth that is unregulated worldwide. In this paper we examine the performance of several modulation schemes on the wireless infraredcommunication system. We compare the power and bandwidth efficiency of several schemes.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.663-664
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• 2007

지중송전선로 건설공사에 154kV 장조장 케이블 드럼개발 및 트레일러 일체형 Under Roller 방식을 이용한 포설장비를 개발하여 현장에 적용함으로써 신기술 신개발 공법 적용으로 인한 국제경쟁력 향상 뿐만 아니라 접속경간의 장조장 설계로 케이블 접속개소 감소로 인한 공사비절감과 공사기간 단축에 크게 기여하였다. 이와 동시에 공사를 위한 도로점용 단축으로 민원발생을 크게 감소시켰다. 현행 도로법 규제로 케이블의 운반중량이 제한되었던 케이블 표준 경간을 450m에서 최대 700m까지 가능하여 접속개소의 유연성이 확보되었을 뿐만 아니라 토목구조물(전력구,관로등)공사의 다양한 설계방법을 적용할 수 있게 되었다.

• Journal of the Korean Society of Radiology
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• v.18 no.3
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• pp.293-300
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• 2024

On October 31, 2023, the revision of the Medical Technologist Act made it mandatory to complete field training courses in order to obtain a license as a radiologic technologist. Therefore, we would like to survey the actual situation of field training in medical institutions to inform the revised Medical Technologist Act and propose improvement measures to increase the effectiveness of field training. A survey was conducted from March to April, 2023, among radiologic technologists working in medical institutions. The questionnaire was sent through a form on a domestic portal site, Company N, and 120 respondents completed it. Eighty-two respondents, or 68.3 percent, had experience in educating on-the-job training students. 58% of the respondents were aware of the fact that the amendment to the Act on Medical Technologist etc. made field training mandatory to obtain a radiologic technologist license. In accordance with Article 9 of the Medical Technologist Act, which prohibits unlicensed persons from practicing, 50% of the respondents were aware that those who are in training to complete an education course equivalent to the license they are seeking to obtain at a university or other institution are allowed to practice as medical Technologists. When asked what is currently taught during fieldwork, 6% of respondents said that they are required to perform radiation-generating activities in addition to observing, guiding patients, and positioning and moving patients. When asked about the future direction of education as fieldwork becomes mandatory for licensure, 77% of respondents said that they will teach more than they currently do. When asked about the appropriate total length of fieldwork, 35% said 12 weeks and 480 hours, 33% said 8 weeks and 320 hours, and 27% said 16 weeks and 640 hours. It can be seen that the current on-the-job training is inadequate according to various regulations, and students' satisfaction is low. However, with the revision of the Act on Medical Technologists, field training has become mandatory to obtain a license as a radiologist, and it is necessary to improve the educational conditions of field training. Therefore, it is necessary to comply with the Nuclear Safety Act and the Rules on the Safety Management of Diagnostic Radiation Generating Devices, introduce standardized training objectives and evaluation systems, designate training hospitals and radiologists in charge of training, and introduce extended training periods and simulation exercises to internalize field training.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.219-221
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• 2004

국가의 규제기관과 처분장에서는 방사성 폐기물의 안전한 영구처분을 위하여 폐기물 수용(인수)기준을 폐기물 발생자에게 준수토록 요구하게 되는데 이러한 폐기물 수용(인수)기준은 처분시설의 가동동안 인간과 환경 보호 그리고 최대 300년간의 제도적 통제기간을 고려하여 처분장의 안전성 확보를 위하여 설정되어진다. 폐기물 수용(인수)기준중 고화체의 안정성 평가와 관련하여 미국(NRC/BTP)은 폐기물의 종류와 고화매질에 따라 유리수, 압축강도, 방사성 조사특성, 미생물 영향 특성, 침수 및 침출 특성, 열순환 특성 등에 대하여 표준시험법을 제시하였으며, 또한 그의 기술기준치도 제시하고 있다. 그리고 프랑스(DRDD/ BECC)에서는 미국보다 매우 세밀하게 평가항목들을 분류하는 등의 처분장 운영국가에서는 고화체의 안정성관련 평가시험들을 처분 환경과 처분방식에 맞게 표준화하고 있다. 한편 국내에서는 과기부 고시 제2001-32호 "중.저준위 방사성폐기물 인도규정"이 있으나 이에는 고화체 관련하여 정성적인 안정성에 대하여서만 기술되어 있다. 이에 따라 원전폐기물 고화체에 대한 안정성 평가를 위한 시험법을 선정하기 위하여 아래 그림과 같은 절차에 따라 수행토록 하였다. 우선 대표적인 천층처분 운영국가인 미국과 프랑스의 시험법 그리고 IAEA 권고 시험법과 유사관련 한국 산업표준법들을 조사하고, 이들 시험법들의 주요 차이점을 기술적 관점에서 비교평가하고, 이어서 모의 방사성 및 비방사성 고화체를 이용하여 상기 시험법들을 각각 적용하고 또한 이들 시험법들간의 차이(시험 조건, 시편의 크기 등)에 기인한 상호 비교시험을 통하여 얻어진 시험결과들을 종합적으로 비교 검토하여 보수적 관점에서 시험법을 선정하는 것으로 방향을 잡았다. 이때 시험결과를 얻기 위한 모든 과정에 품질보증 활동을 적용키로 하였으며, 시험결과 분석/평가 과정과 시험법 선정에 각계(규제기관, 학계, 발전소 현장 및 산업계 등) 전문가로부터 기술자문회의를 통하여 자문 의견을 받기로 하였다. 특히 현재 폐기물 인수 기술기준치가 설정된 국가의 시험법을 심층 있게 검토하기로 하였다.검토하기로 하였다.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.581-594
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• 2017

Bisphenol A(BPA), known as a typical endocrine disruptor, has been used commercially and widely for plastics and epoxy resins. BPA-based plastic is used extensively for the production of water bottles, food containers, CDs, DVDs, and panels that can be applied in construction. Epoxy resins containing BPA are used for coatings on the insides of water pipes, food cans, and thermal papers that are used in sales receipts. As its estrogenic effects and other adverse health effects have published, BPA has been regulated in many countries, and there have been efforts made to replace BPA. Other bisphenols substitutes such as bisphenol S(BPS) and bisphenol F(BPF) have been used. Currently, BPS- and BPF-based products labeled BPA-free products have been widely consumed. Because of structural similarities with BPA, however, these alternatives also show endocrine disruption effects like BPA, and many studies on adverse health effects of these alternatives are being reported. In this review, we describe the adverse health effects of bisphenols and the current status of regulation.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.28-28
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• 2009

최근 전세계적으로 유가 상승 및 배기가스 배출 저감과 관련된 각종 환경규제에 대응하기 위하여 선진 자동차회사들은 $CO_2$ 배출 저감 기술과 기존 내연기관 차량의 연비향상을 위해 엔진성능 개선, 구동시스템의 최적화, 차량 경량화, 공기저항 감소 등에 초점을 맞춰 차량의 연비향상과 배기가스 규제에 대응하고 있다. 특히, 자동차 중량의 30%를 차지하는 차체의 경량화는 엔진효율을 높여 자동차의 성능향상을 극대화시키고, 그로 인해 연비향상을 도모할 수 있으므로 환경오염 방지와 연료절감에 가장 적합하고 효과적인 방법이다. 이에 기존의 강재에 비해 비중이 낮으면서 유사한 강도와 내식성이 뛰어난 알루미늄 합금의 차체 적용에 대한 연구가 진행되고 있다. 본 연구에서는 자동차 Door에 알루미늄 합금(Al 5052)의 적용 가능성을 판단하기 위해 반응표면분석법(Response surface methodology)을 이용하여 저입열 Pulse MIG 용접 공정변수를 최적화하였다. 첫째, 저입열 Pulse MIG 용접에서 용접 공정 변수(용접전압, 용접속도, Gap)의 변화가 비드 형상에 미치는 영향에 대해 평가하였다. 요인분석법을 이용하여 용접 공정 변수와 비드 형상 변수와의 주효과와 교호작용효과를 분석하였고, 이를 통해 비드 형상 변수에 영향을 크게 미치는 용접 공정변수를 선별하여 다중회귀분석을 통해 용접 공정 변수 변화에 따른 비드형상 예측 회귀모델을 제안하였다. 둘째, 자동차 Door 생산 현장에서 박판 알루미늄 합금 겹치기 용접 이음부의 0~1 mm 갭 발생에 대해 강건한 용접조건을 제시하기 위해 반응표면법(Response surface methodology)을 이용하여 저입열 Pulse MIG 용접 공정 변수를 최적화하였고, 그 적용 가능성을 확인하였다.

• Proceedings of KOSOMES biannual meeting
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• 2008.05a
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• pp.11-17
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• 2008

As of Jan. 2006, numbers of korean registered ocean-going vessels reached 546 which amounted to 13,716,733 G/T. Vessels, generally spooking, finish her life cycle and are dismantled or recycled. However, most of these activities have been done in undeveloped countries instead of in developed countries as the environmental restrictions in developed countries get more strict, accordingly international bodies adopted shipbreaking-related guidelines and prohibit transboundary of obsolete ships, taken as one of wastes. The authors made the Working Guidelines on Shipbreaking to cope with substandard working environment and reduce the environmental damage, and came up with a method to make a inventory of hazardous materials for effective control, finally framed a draft of Environmentally Sound Ship Recycling examining related international conventions such as Basel Convention, IMO Guideline, ILO Guideline and IMO new Convention(draft) on shipbreaking and recycling.

• Explosives and Blasting
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• v.41 no.1
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• pp.32-45
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• 2023

Environmental regulations in Korea for blasting at industrial sites have conservative standards, which often result in reduced efficiency and cost-effectiveness due to the consideration of environmental regulations and public complaints. Therefore, there is a need for blasting methods that can reduce environmental damage while improving construction efficiency and cost-effectiveness. In this study, we analyzed the effects of the PA-Deck (Paraffin Air-Deck) blasting method, which is a kind of Air Decoupled Charge method in principle utilizing a paraffin-infused paper tube as an air gap, on reducing blasting hazards and improving blasting efficiency. The analysis also evaluated the effectiveness of newly applied equipment for collecting blasting vibration data, and derived the relationship between the explosion velocity and vibration velocity of explosives, and performed frequency analysis of the vertical component. The results of the blasting vibration velocity analysis showed that the Paraffin Waxed Paper Tube-based blasting method exhibited significantly lower vibration velocities compared to conventional blasting methods, and it was judged that more uniformly small-sized fragmented rocks were generated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.310-315
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• 2017

Although studies evaluating the effects of the blasting vibration on the adjacent structures from various angles have continued, cases of securing the safety of the adjacent buildings and researching the proper blasting method for the field condition by analyzing the vibration waveform of the measuring field while performing the open pit blasting are poor. Therefore, it is necessary to present a remedy for blasting pattern selection through test blasting that is appropriate for field conditions, and is economical and efficient. In this study, open pit blasting work was conducted based on the separation distance applied according to the standard blasting method by test blasting and the vibration regulation standard in the road expansion construction site to measure the blasting vibration value, and the vibration prediction equation by blasting methods was examined using a regression analysis computer program to calculate K, N, and R of the confidence level 95%. By setting the blasting allowed vibration standard of the test blasting target area to 0.3cm/sec, and the charring weight and blasting method by the separation distances according to the blasting vibration estimation equation of the open pit blasting guideline and the blasting vibration estimation equation of the test blasting were compared/analyzed, it was possible to identify the factors that increased the working expenses. In addition, the measurement and analysis of the adjacent structures during open pit blasting and the blasting vibration were performed after selecting the most adjacent structure to the open pit blasting spot to analyze the problems on the test blasting procedure and analysis method in the open pit blasting design/construction guidelines, which appeared in the process of completing open pit blasting construction, and a remedy is presented.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.2
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• pp.121-141
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• 2017

The thermal analysis of an underground power conduit for electrical cables is essential to determine their current capacity with an increasing number of demands for high-voltage underground cables. The temperature rises around a buried cable, caused by excessive heat dissipation, may increase considerably the thermal resistance of the cables, leading to the danger of "thermal runaway" or damaging to insulators. It is a key design factor to develop the mechanism on thermal behavior of backfilling materials for underground power conduits. With a full-scale field test, a numerical model was developed to estimate the temperature change as well as the thermal resistance existing between an underground power conduit and backfill materials. In comparison with the field test, the numerical model for analyzing thermal behavior depending on density, moisture content and soil constituents is verified by the one-year-long field measurement.