• Journal of the Optical Society of Korea
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• 제13권1호
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• pp.2-7
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• 2009

This paper reviews evolution of the research networks on intense laser science under international and Asian frameworks during 2000 to 2008. The OECD Global Science Forum Steering Committee on Compact, High-Intensity Short-Pulse Lasers led to the establishment of the International Union of Pure and Applied Physics (IUPAP) Working Group: International Committee on Ultrahigh Intensity Lasers (ICUIL) and the Asian Intense Laser Network (AILN) in 2004. Through various activities under AILN such as the Asian Symposium on Intense Laser Science (ASILS), the Asian Summer School on Laser Plasma Acceleration and Radiation, and the High-Order Harmonics Workshops, closer relations are being formed among the scientists and also among the young generations working in intense laser science in the Asian regions.

• 항공우주산업기술동향
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• 제8권2호
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• pp.65-75
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• 2010

일본은 향후 2014년으로 발사가 예정되어 있는 GCOM-C를 이용하여 지구 복사량 및 탄소의 변화량, 해색정보, 에어로졸 분포 등을 측정할 계획을 추진 중이다. 특히, GCOM-C에는 SGLI-VNR과 SGLI-IRS로 구성되어 있는 SGLI를 탑재하고 있으며, 각각 가시영역/근적외영역과 적외영역의 영상을 측정하도록 설계될 예정이다. SGLI는 최신 성능을 갖춘 설계부분과 함께 기본적인 기능 및 구조 등은 지금까지 일본에서 개발되어진 여러 광학 탑재체들의 개발기술들을 바탕으로 구현됨으로써, 개발위험을 최소화 하는 전략을 취하고 있다. 본 논문에서는 지금까지 일본이 개발한 여러 광학 탑재체들의 특성들을 채널별(가시영역/근적외영역과 적외영역)로 비교 및 검토하면서, 향후 개발 완료될 SGLI의 특성을 이해하고 일본의 광학탑재체 개발 경향에 대한 분석을 수행하고자 한다.

• 대기
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• 제32권1호
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• pp.17-25
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• 2022

As climate change due to global warming continues to be accelerated, various extreme events become more intense, more likely to occur and longer-lasting on a much larger scale. Recent studies show that global warming acts as the primary driver of extreme events and that heat-related extreme events should be attributed to anthropogenic global warming. Among them, both terrestrial and marine heat waves are great concerns for human beings as well as ecosystems. Taking place around the world, one of those events appeared over East Sea in July 2021 with record-breaking high temperature. Meanwhile, climate condition around East Sea was favorable for anomalous warming with less total cloud cover, more incoming solar radiation, and shorter period of Changma rainfall. According to the results of wave activity flux analysis, highly activated meridional mode of teleconnection that links western North Pacific to East Asia caused localized warming over East Sea to become stronger.

• 한국의학물리학회지:의학물리
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• 제28권2호
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• pp.61-66
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• 2017

The aim of this study is to investigate the characteristics of portal dosimetry in comparison with the MapCHECK2 measurments. In this study, a total of 65 treatment plans including both volumetric modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT) were retrospectively selected and analyzed (45 VMAT plans and 20 IMRT plans). A total of 4 types of linac models (VitalBeam, Trilogy, Clinac 21EXS, and Clianc iX) were used for the comparison between portal dosimetry and the MapCHECK2 measurements. The VMAT plans were delivered with two VitalBeam linacs (VitalBeam1 and VitalBeam2) and one Trilogy while the IMRT plans were delivered with one Clinac 21EXS and one Clinacl iX. The global gamma passing rates of portal dosimetry and the MapCHECK2 measurements were analyzed with a gamma criterion of 3%/3 mm for IMRT while those were analyzed with a gamma criterion of 2%/2 mm for VMAT. Spearman's correlation coefficients (r) were calculated between the gamma passing rates of portal dosimetry and those of the MapCHECK2 measurements. For VMAT, the gamma passing rates of portal dosimetry with the VitalBeam1, VitalBeam2, and Trilogy were $97.3%{\pm}3.5%$, $97.1%{\pm}3.4%$, and $97.5%{\pm}1.9%$, respectively. Those of the MapCHECK2 measurements were $96.8%{\pm}2.5%$, $96.3%{\pm}2.7%$, and $97.4%{\pm}1.3%$, respectively. For IMRT, the gamma passing rates of portal dosimetry with Clinac 21EXS and Clinac iX were $99.7%{\pm}0.3%$ and $99.8%{\pm}0.2%$, respectively. Those of the MapCHECK2 measurements were $96.5%{\pm}3.3%$ and $97.7%{\pm}3.2%$, respectively. Except for the result with the Trilogy, no correlations were observed between the gamma passing rates of portal dosimetry and those of the MapCHECK2 measurements. Therefore, both the MapCHECK2 measurements and portal dosimetry can be used as an alternative to each other for patient-specific QA for both IMRT and VMAT.

• 한국농림기상학회지
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• 제11권2호
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• pp.79-85
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• 2009

순복사는 지표와 대기간의 생물학적/물리적 과정을 일으키는 주요 원인이며 순복사에 대한 정확한 정보는 기후 예측뿐만 아니라 수자원관리에 중요한 역할을 한다. 그러나 실제 순복사 관측을 하는 지점은 매우 적으며 일반적으로 순복사는 단순 경험방정식으로부터 추정된다. 이 연구에서는 한국의 세 개의 다른 식생기능형태(예, 혼합림, 침엽수림, 그리고 농경지)에서 순복사를 추정하는 두 방법을 제시하였다. 첫번째 방법은 순복사와 전천일사의 관계를 선형회귀식으로 나타낸 방법이고 두번째 방법은 복사수지방정식을 사용한 방법이다. 세 개의 다른 식생기능형태에서 관측된 2008년 자료를 두 방법에 적용하여 순복사를 추정하였다. 일년 자료를 사용하여 선형회귀식을 적용한 결과, 전천일사에 대한 순복사의 비율은 혼합림에서는 70%, 침엽수림에서는 79%, 그리고 농경지에서는 64%를 보였다. 이는 다른 식생기능형태에 따라 순복사와 전천일사의 관계가 달라짐을 보였다. 장파복사를 고려한 복사수지 방정식의 경우, 순복사 추정이 다소 향상되었다. 두 방법 모두 관측된 순복사와 추정된 순복사가 잘 일치함을 보였으며 이는 두 방법을 사용하여 순복사를 추정할 수 있음을 보여준다.

• 천문학회지
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• 제28권1호
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• pp.67-70
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• 1995

In contrast to conventional belief that extended inflation ends when the Universe percolates, we find inflation may continue at least many Hubble times even after the Universe percolates. What is observed is that inflation will not stop unless the global equation of state changes from inflationary one into radiation one. Thus the energy density of shorter wavelength gravitational waves induced by bubble collision at near the end of inflation should be at least Order $(10^2)\~O(10^3)$ times greater than previous estimation of Turner and Wilcek(TW).

• 태양에너지
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• 제13권2_3호
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• pp.107-119
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• 1993

This paper is to refine the concept of utilizing natural energy, and to introduce new technologies of building energy control. For the global environment protection, it is essential to turn attention to latent capacity of natural renewable energy. Especially the concept of 'Environmental Architecture' is very important from this viewpoint. This paper reviews many of new technologies for environmental architecture developed recently : TIM, high effective solar radiation control strategy of glazing, new passive cooling and heating system etc. The design application of the technology has been introduced.

• Korean Journal of Radiology
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• 제22권1호
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• pp.97-105
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• 2021

Objective: The present study aimed to investigate the association between myocardial blood flow (MBF) quantified by dynamic CT myocardial perfusion imaging (CT-MPI) and the increments in heart rate (HR) after stress in patients without obstructive coronary artery disease. Materials and Methods: We retrospectively included 204 subjects who underwent both dynamic CT-MPI and coronary CT angiography (CCTA). Patients with more than minimal coronary stenosis (diameter ≥ 25%), history of myocardial infarction/revascularization, cardiomyopathy, and microvascular dysfunction were excluded. Global MBF at stress was measured using hybrid deconvolution and maximum slope model. Furthermore, the HR increments after stress were recorded. Results: The median radiation dose of dynamic CT-MPI plus CCTA was 5.5 (4.5-6.8) mSv. The median global MBF of all subjects was 156.4 (139.8-180.4) mL/100 mL/min. In subjects with HR increment between 10 to 19 beats per minute (bpm), the global MBF was significantly lower than that of subjects with increment between 20 to 29 bpm (153.3 mL/100 mL/min vs. 171.3 mL/100 mL/min, p = 0.027). This difference became insignificant when the HR increment further increased to ≥ 30 bpm. Conclusion: The global MBF value was associated with the extent of increase in HR after stress. Significantly higher global MBF was seen in subjects with HR increment of ≥ 20 bpm.

• 생물환경조절학회지
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• 제8권3호
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• pp.192-201
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• 1999

본 연구는 ASKAM모델로 $CO_2$, 광 및 엽면적지수가 단고추의 동적 광합성율에 추정가능성을 평가하기 위하여 수행되었다 $CO_2$ 농도는 2구획으로 구분된 반밀폐된 생장상에서 3수준 (400, 700 or 1000$\mu$mo1 mol$^{-1}$)으로 조절하였다. 온도와 습도는 21$^{\circ}C$ 및 80-95%로 조절하였고, 양액이 순환되는 용기내에서 재배하였다. 일태양복사, 온도 및 $CO_2$농도의 단기 자료를 기초로 하여 일중 단기간격에 대한 작물 순$CO_2$흡수량를 ASKAM모델로 추정하였고, 광합성 측정 중 각 구획과 기부에서의 $CO_2$농도를 매분마다 측정하였다. 순수 $CO_2$의 구획으로의 흐름, 지상방사, 구획내의 광합성유효방사, 은도 및 상대습도를 측정하였다. 본 작물생장모델은 작물의 광합성율을 적절하게 추정할 수 있는 것으로 평가되므로 생장해석, 작물관리 및 온실관리에 광범위하게 적용될 수 있을 것으로 판단되었다.

• Journal of Radiation Protection and Research
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• 제47권1호
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• pp.16-21
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• 2022

Background: Epidemiological observations such as mental retardation, physical deformities, etc., in children besides different types of cancer in the adult population of the Malwa region have been reported. The present study is designed to get insight into the role of naturally occurring radioactive material (NORM) in causing detrimental health effects observed in the general population of this region. Materials and Methods: Deep soil samples were collected from different locations in the Malwa region. Their activity concentrations were determined using low-level background gammaray spectrometry. High efficiency and high purity germanium detector capped in a lead-shielded chamber having a resolution of 1.8 keV at 1,173 keV and 2.0 keV at the 1,332 keV line of ⁶⁰Co was used in the present work. Data were evaluated with Genie-2000 software. Results and Discussion: Mean activity concentrations of ²³⁸U, ²³²Th, and ⁴⁰K in deep soil were found to be 101.3 Bq/kg, 65.8 Bq/kg, and 688.6 Bq/kg, respectively. The mean activity concentration of ²³⁸U was found to be three and half times higher than the global average prescribed by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). It was further observed that the activity concentration of ²³²Th and ⁴⁰K has a magnitude that is nearly one and half times higher than the global average prescribed by UNSCEAR. In addition, the radioisotope ¹³⁷Cs which is likely to have its origin in radiation fallout was also observed. It is postulated that the NORM present in high quantity in deep soil somehow get mobilized into the water aquifers used by the general population and thereby causing harmful health problems. Conclusion: It can be stated that the present work has been able to demonstrate the use of low background gamma-ray spectrometry to understand the role of NORM in causing health-related effects in a general population of the Malwa region of Punjab, India.