창원직업훈련원

이기일(Ki Il Lee) 대한공업교육학회 1977 대한공업교육학회지 Vol.2 No.1

절리암반의 변형률 의존적 전단탄성계수 및 감쇠비 특성을 고려한 터널의 내진 해석

송기일,정성훈,조계춘,이정학,Song, Ki-Il,Jung, Sung-Hoon,Cho, Gye-Chun,Lee, Jeong-Hark 한국터널지하공간학회 2010 한국터널지하공간학회논문집 Vol.12 No.4

Contrary to an intact rock, the jointed rock mass shows strain-dependent deformation characteristics (elastic modulus and damping ratio). The maximum elastic modulus of a rock mass can be obtained from an elastic wave-based exploration in a small strain level and applied to seismic analyses. However, the assessment and application of the non-linear characteristics of rock masses in a small to medium strain level ($10^{-4}{\sim}0.5%$) have not been carried out yet. A non-linear dynamic analysis module is newly developed for FLAC3D to simulate strain-dependent shear modulus degradation and damping ratio amplification characteristics. The developed module is verified by analyzing the change of the Ricker wave propagation. Strain-dependent non-linear characteristics are obtained from disks of cored samples using a rock mass dynamic testing apparatus which can evaluate wave propagation characteristics in a jointed rock column. Using the experimental results and the developed non-linear dynamic module, seismic analyses are performed for the intersection of a shaft and an inclined tunnel. The numerical results show that vertical and horizontal displacements of non-linear analyses are larger than those of linear analyses. Also, non-linear analyses induce bigger bending compressive stresses acting on the lining. The bending compressive stress concentrates at the intersection part. The fundamental understanding of a strain-dependent jointed rock mass behavior is achieved in this study and the analytical procedure suggested can be effectively applied to field designs and analyses. 암석과는 달리 절리암반은 변형률 의존적 변형특성(탄성계수 및 감쇠비)을 나타낸다. 탄성파를 이용한 현장실험을 통해 미소변형률 수준에서 암반의 최대탄성계수를 얻을 수 있으며 이를 내진 설계에 반영하고 있으나, 미소 변형률 이상의 중변형률($10^{-4}{\sim}0.5%$) 영역의 동적거동에 대한 실험적인 규명과 이에 대한 수치적 적용은 전무한 실정이다. 본 연구에서는 변형률 의존적 전단탄성계수 및 감쇠비의 비선형 거동 특성을 반영하여 동적해석을 수행할 수 있는 FLAC3D 해석 모듈을 개발하였다. 리커 웨이브의 파동 변화를 분석하여 개발된 모듈에 대한 검증을 수행하였다. 절리 암반의 탄성파 전파특성과 동적 거동특성을 모사할 수 있는 절리암반 공진주 시험장비를 통하여 현장에서 채취한 절리암반의 변형률 의존적 전단탄성 계수의 감쇠 특성과 감쇠비의 증폭 특성을 획득하였다. 개발된 비선형 해석 모듈에 실험으로부터 획득된 거동 특성을 반영하여 수직구와 사갱의 접속부에 대한 내진 안정성 평가를 수행하였다. 내진해석 결과, 비선형 해석이 선형 해석보다 더 큰 연직변위와 수평변위 결과를 나타냈다. 라이닝의 휨압축응력은 수직구과 사갱의 접속부에서 집중되는 것으로 나타났으며 비선형해석의 경우 라이닝에 더 큰 휨압축응력이 발생되는 것으로 나타났다. 본 연구를 통하여 변형률 의존적 절리암반의 비선형 거동특성을 보다 깊이 있게 이해하고 해석 및 설계시 고려할 수 있을 것으로 사료된다.

조종사비행(근무)시간기준에 대한 항공규정개선방안 연구 (FRMS를 중심으로)

이기일,Lee, Ki-Il 한국항공운항학회 2017 한국항공운항학회지 Vol.25 No.1

Approximately 70% of aviation accidents in the world are caused by human factors of pilots and 15-20% of these accidents are known to be caused by pilot fatigue. Recently ICAO established new standards of FRMS for aircrew. The US and the EU have introduced FRMS and established and operated new aviation regulation systems for pilot flight(duty) time limitations. On the other hand, Korea has not yet introduced FRMS. This study reviewed ICAO's standards of FRMS and analyzed the aviation regulations of the US and the EU. As a result of this study, it showed that Korea also needed to introduce FRMS. This study reasoned out plans to improve Korean aviation regulations about pilot flight time limitations based on international standards.

항공영어구술능력증명시험 개선방안 연구

이기일,Lee, Ki Il 한국항공운항학회 2016 한국항공운항학회지 Vol.24 No.4

ICAO(International Civil Aviation Organization) established ICAO LPRs(Language Proficiency Requirements) which is an international standard of English for aviation to promote the aviation safety. The Republic of Korea government amended the aviation law on the 8th of November, 2005 and made EPTA(English Proficiency Test for Aviation) as a follow up action. Purpose of this research is analysing the problem of EPTA and improving it. This investigation takes a look at the current ICAO LPRs and compares the difference between EPTA and other global English proficiency requirements for aviation. The result indicated that there is a discordance between the standards of ICAO and EPTA. Also, the global English proficiency reqirements for aviation and EPTA had differences which required improvements. The study suggests to replace more job relevant questions in the EPTA and reform the level system of EPTA.

지하공간에서 노무자의 위치 인식을 위한 RTL 시스템 개선

송기일,임진선,이항로,Song, Ki-Il,Lim, Jin-Sun,Lee, Hang-Lo 한국터널지하공간학회 2016 한국터널지하공간학회논문집 Vol.18 No.3

Real time location (RTL) system which can control the safety of laborers in the underground space is developed in this study. This innovative system can monitor the location and history of movement of multiple laborers in real time. To accommodate constrains of the underground space, the system is portable and composed with low-battery mode. Since conventional method to detect the location of laborer with radio signal strength indicator (RSSI) contains high errors, new measurement system using accelerometers and correction method are suggested in this study. Field test is performed to validate the developed system. The error for moving laborer was 0.4 m and for non-moving laborers was 0.2 m. Thus, it is found that the new RTL system can be used to monitor the location of laborers in the underground construction space. 본 연구에서는 터널 및 지하건설현장에서 노무자의 안전을 관리할 수 있는 실시간 위치정보 시스템을 개발하였다. 이 시스템은 다수의 노무자들에 대한 실시간 위치 탐색 및 이동 이력을 확인할 수 있다. 이 시스템은 지하공간에서 다양한 노무자들의 이동 특성을 손쉽게 파악하기 위하여 저전력의 이동이 용이한 시스템으로 구성하였다. RSSI를 이용한 삼각측량으로 위치 인식을 하는 과거의 방법은 매우 큰 오차를 가지는 이유로 가속도계를 이용한 새로운 거리측정 방법 및 보정 방안을 제시하였다. 지하건설현장에서 개발한 시스템을 평가한 결과 움직임이 없는 경우 약 0.2 m 오차를 나타내었고, 움직임이 있는 경우 약 0.4 m의 오차가 발생하였으며, 현장에서 충분히 활용할 만한 결과를 나타내었다.

대기오염이 알레르기비염에 미치는 영향

이기일 ( Ki-il Lee ),정영준 ( Young-jun Chung ),모지훈 ( Ji-hun Mo ) 대한천식알레르기학회(구 대한알레르기학회) 2021 Allergy Asthma & Respiratory Disease Vol.9 No.1

Recently, air pollution has become more and more severe globally and has decreased the quality of life significantly in subjects with or without allergic diseases. Air pollution more severely affects patients with allergic diseases, including allergic rhinitis (AR); therefore, it could devastate quality of life. Many epidemiological studies have shown that air pollutants increased outpatient clinic visits as well as the prevalence/severity of AR and decreased quality of life in patients with AR. Traffic-related air pollution also increases the severity and occurrence rate of AR, and heavy traffic is also associated with an increased prevalence of AR. Immunologically, air pollutants increase airway inflammation and mucin production by triggering the generation of reactive oxygen species and inducing the nucleotide-binding domain, leucine-rich repeat protein 3 inflammasome and apoptosis. Since air pollution affects both the upper and lower airways and is known to be a risk factor for AR, proper diagnosis and treatment should be applied. In this review article, we will address several epidemiological and clinical studies about the effects of air pollution on AR, mechanisms by which air pollutants aggravate AR, and treatment of AR triggered by air pollutant. (Allergy Asthma Respir Dis 2021;9:3-11)

국외근로자 비과세제도 개선방안 연구 : 국제선항공승무원을 중심으로

이기일,김수련,Lee, Ki Il,Kim, Soo Ryun 한국항공운항학회 2015 한국항공운항학회지 Vol.23 No.3

Since the tax-free system for overseas laborers was implemented in 1974, the tax-free limits of international air crew, overseas construction workers and crewmen of deep-sea fishing ships and ocean-going ships had been identical by 2005, but there are big differences, currently. The Ministry of Strategy and Finance pointed out the poor working environments and international competitiveness of the industries to explain the reason for the differential tax-free limit. From this perspective, the fairness of the tax-free system for overseas laborers was analyzed. This is an empirical study, based on the objective fact. The study finding showed that international air crew were working in the structural flight work environments to threaten the right of health due to jet lag and excessive exposure to high-altitude cosmic radiation. Therefore, it was analyzed there should be a proper system reform to apply the tax-free limits to international air crew which are identical to those applied to overseas construction workers and crewmen of deep-sea fishing ships and ocean-going ships, for a fair taxation.

TBM 굴진성능 예측모델 분석: 리뷰

이항로,송기일,조계춘,Lee, Hang-Lo,Song, Ki-Il,Cho, Gye-Chun 한국터널지하공간학회 2016 한국터널지하공간학회논문집 Vol.18 No.2

Prediction of TBM performance is very important for machine selection, and for reliable estimation of construction cost and period. The purpose of this research is to analyze the evaluation process of various prediction models for TBM performance and applied methodology. Based on the solid literature review since 2000, a classification system of TBM performance prediction model is proposed in this study. Classification system suggested in this study can be divided into two stages: selection of input parameter and application of prediction techniques. We also analyzed input and output parameters for prediction model and frequency of use. Lastly, the future research and development trend of TBM performance prediction is suggested. TBM을 적용하는 현장에서 장비 선택, 공사기간 및 공사비용의 합리적인 산정을 위하여 TBM의 굴진성능을 정확하게 예측하는 것은 매우 중요한 사안이다. 본 연구에서는 최신 자료들을 바탕으로 기존의 TBM 굴진성능 예측모델들의 평가과정과 방법론에 대한 분석을 수행하였다. 2000년 이후에 발표된 문헌들에 대한 조사를 토대로 TBM 굴진성능 예측모델의 분류체계를 제시하였다. 본 연구에서 제시한 분류체계에서는 TBM 굴진성능 예측모델에 필요한 입력인자 선정단계와 예측기법 적용단계로 크게 구분하였다. 또한 각 예측모델에서 사용된 입력인자, 출력인자 그리고 예측모델에서 사용된 인자의 적용빈도를 분석하였다. 마지막으로 TBM 굴진성능 예측모델의 현황과 향후 연구방향에 대하여 제언하였다.

Shield TBM 순굴착속도 실시간 예측

이항로(Lee, Hang-Lo),송기일(Song, Ki-Il),류희환(Ryu, Hee-Hwan),김경열(Kim Kyoung-Yul),이지영(Rhee Jiyoung) 대한토목학회 2022 대한토목학회 학술대회 Vol.2022 No.10

개별요소법을 이용한 17인치 디스크커터의 선형절삭시험 수치해석 및 성남편마암 지반에서의 최적 S/P비 산정

이상연(Lee, Sang Yun),송기일(Song, Ki il),최창순(Choi, Chang Soon),이동건(Lee, Dong Gun),정주환(Jung, Ju Hwan) 대한토목학회 2020 대한토목학회 학술대회 Vol.2020 No.10