• Journal of the Korean Society of Radiology
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• v.12 no.3
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• pp.351-357
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• 2018

During radiation therapy, the patient is exposed to secondary radiation by scattered and leakage radiation. For the diagnostic radiation, guidelines for reducing the patient's exposure as the diagnostic reference level are provided. However, in the case of therapeutic radiation, even though the radiation dose by the secondary radiation is considerable, the prescription dose is not limited because of the reason of the therapeutic efficiency. The purpose of this study was to evaluate the secondary radiation that the patient could be received at the peripheral tissue during the radiotherapy using the linear accelerator with the radiophotoluminescent glass dosimeter. In addition, we measured the degree of saturation of the luminescent amount according to the build-up characteristic of the radiophotoluminescent glass dosimeter. As a result of carrying out this study, the exposure dose decreased drastically farther away from the treatment field. When the head was irradiated with 1 Gy, the neck could be exposed to 18.45 mGy. When the same dose was irradiated at the neck, 15.55 mGy of the head and irradiated at the chest, 14.26 mGy of the neck and irradiated at the pelvis, 1.14 mGy of the chest were exposed separately. The degree of saturation of the luminescent intensity could be overestimated by 1.8 ~ 4.8% depending on time interval for 3 days.

• Journal of radiological science and technology
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• v.32 no.4
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• pp.411-418
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• 2009

To evaluate the bone mineral density (BMD) and biochemical markers. We evaluated the BMD of femoral neck and lumbar spines of 998(male 568, female 430) persons who took a regular health screening in Woosuk University Hospital from September 2007 to March 2008 by dual energy bone mineral densitometry. Results of BMD are different in terms of biochemical markers. Especially aged people showed osteoporotic change progressively. Degree of osteoporosis increases with age. A steep decrease of BMD can be found in postmenopausal women who have low level of female hormone. More persistent effort is needed to find out the factors that can reduce BMD values for prevention of problems by osteoporosis. In essence, research on factors related to other biochemical markers must be studied continuously.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1935-1942
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• 2011

We have tested the developed Korean tilting train in main exisiting commercial line for speed-up on cuve section to achive reduction effects of running time. We have conducted a trial run test to speed-up 30km/h on curves in Gyeongbu line successfully. Normal current train have been operated 110km/h in 600m radius. Yet, tilting train was tested 135km/h(maximum operation line speed) in same sections. We confirmed that the dynamic runing stability of train was safety by regarding wheel load and lateral force.

• Tuberculosis and Respiratory Diseases
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• v.44 no.5
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• pp.957-963
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• 1997

결핵성 임파선염은 아직도 한국에서 많이보는 질환이며 젊은여자 성인 특히 아시아인이나 흑인에서 가장 흔하다. 이 질환은 두경부에 흔히 무통성으로 서서히 림프절이 커지는 양상을 보이나 인체내 결절이 있는 어디나 오며 종격동 결절에도 온다. scrofula(선통(腺病))는 다양한 종양, 비종양성 종괴, 감염질환 특히 경부임파선염 풍과 구별되야만 한다. 비록 병력, 역학, 임상양상 흉부 엑스선 그리고 결핵반응검사로써 만족할만한 진단을 내리지만 절제생검으로 조직 및 배양이 필요하기도 하다. 궤양이나 만성 누공 형성을 막기위해 부분생검이나 절개 및 배농은 반드시 피해야 한다. 치료는 항결핵화학요법이며 가끔 외과적 적출술이 약물요법과 더불어 요구되기도 한다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1323-1326
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• 2004

A bogie frame of welded type have some problems. Some end beam has cracked. The cracks have profound influence on the safe freight service. The bogie consists of a frame, suspensions, brakes and wheel sets. Various analyses including a numerical simulation using a finite element method, a static load test, a fatigue test, and running test should be carried out to design the bogie. However cracks have been found at some end beams of the bogies mounted on the freight cars running with the high speed. The cracks of the end beam results in deterioration of the brake performance and the running safety. Numerical simulations and dynamic tests are carried out to figure out the causes of cracks in the existing bogie, and the vibrational characteristics of the improved bogie are compared with those of the conventional one. In this reports, the vibration characteristics were dealed with the most pressing matters for the solution of the end beam crack.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1242-1244
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• 2001

전철화 선로에 있어서 공동 접지 방식은 Staff 안전과 선로변 전기 설비에 가장 큰 영향을 인가하는 귀선 전류에 따른 문제점을 해결할 수 있는 최상의 방식으로 평가되고 있으며, 이들 접지 시스템의 구성은 기존의 전력 공급 시스템에 기본을 두고, 전철화에 따라 선택된 궤도 회로의 특성에 의해 모든 설계 변수가 변화되는 원리가 적용된다. 본 논문에서는 이러한 견지에 입각하여 궤도 회로에 의한 공동 접지망 구성 요소를 프랑스 철도청(SNCF)의 규정에 의해 분석한 후, 이를 경부선 전철화 구간에 적용하여 관련 설계 변수를 결정하였다.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.451-456
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• 2004

The KTX has been launched one month ago and people can travel much faster and further. There are two opinions which are the dispersion and the concentration of metropolitan population. These contrary opinions were disputed against each other before launching KTX. The phenomena of metropolitan population concentration socially made many problems as it was already pointed out on many papers. So accurate prediction is very important. Thus, this study will predict how KTX will affect the dispersion of metropolitan population focused on highly populated Seoul-Pusan Railway. It will achieved by comparing and analysing foreign cases.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1601-1602
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• 2015

전력계통에서 진상역률이 될 경우, 경부하시 또는 무부하시 변전소 급전측의 전압보다 말단측의 전압이 높아져 심각할 경우 절연파괴 및 기기에 과전압으로 인한 문제가 발생할 수 있다. 최근 도입된 고속철도 구간에서 무부하시 또는 경부하시 전압이 상승되는 현상이 발생하여 실측 및 시뮬레이션을 통하여 전위 상승에 대한 원인을 검토하고자 한다.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1249-1253
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• 2009

Enhancements of transport capacity in Gyeongbu line are continuous with the operating cost reduction and Korean economic development. Besides, requirements of a people about speed-up and customer service after the opening of high-speed railway(KTX) are being increased nowadays. Therefore, development and effort for speed increase of high-speed railway(KTX) have to be encouraged and supported by the government. In this study, market and technology trends for speed increase of high-speed train in Korea and abroad were investigated. As a result, we suggested to improve the railway infra for speed increase of high-speed train in Gyeongbu line.

• Computational Structural Engineering
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• v.11 no.3
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• pp.253-262
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• 1998

본 연구에서는 경부고속철도의 주요 교량형식인 PSC 박스교량을 3차원 뼈대요소를 사용하여 모형화하였으며, 궤도불규칙성의 형상은 지수 스펙트럴 밀도함수를 사용하여 생성시켰다. 경부고속철도차량(K-TGV)중 동력차는 17자유도의 3차원 주행열차로 모형화하였고, 이러한 교량, 궤도불규칙성 및 차량 모형을 이용하여 교량과 차량의 상호작용을 해석할 수 있는 프로그램을 개발하였다. 동적해석을 위한 교량과 차량의 운동방정식은 Lagrange 방정식을 사용하여 유도하였으며, 운동방정식의 수치해석에는 Newmark-β법을 사용하였다. 개발된 프로그램을 이용하여 동력차의 주행에 의한 교량의 시간이력곡선을 구하였으며, 궤도불규칙성의 영향을 분석하였다. 또한 도상의 유무에 따른 교량동적거동의 특성과 함께 열하중의 편심의 영향도 분석하였다.