• 한국식품영양과학회지
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• 제37권2호
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• pp.195-202
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• 2008

신고배(Pyrus pyrifolia cv. Niitaka)의 휘발성 향기성분에 전자선 조사의 영향과 전자선 조사 후 저장기간에 따른 휘발성 향기성분의 변화를 확인하기 위하여 본 연구를 수행하였다. SDE 추출방법과 GC/MS 분석에 의하여 선량에 따른 신고배의 휘발성 향기성분을 분석하였다. 비조사 신고배와 전자선 0.25, 0.5, 1 그리고 3 kGy로 조사된 신고배에서 각각 46, 45, 44, 48 그리고 51종의 화합물을 동정하였다. 신고배의 주요 휘발성 향기성분으로는 $C_6$ 화합물인 hexanal, n-hexanol, (E)-2-hexenal이 분리 동정되었다. $4^{\circ}C$에서 30일 저장 후 신고배의 휘발성 향기성분의 조성은 유사하였으며, 저장기간 동안 크게 변화가 없었다. 소비자 수용성에 기여하는 휘발성 향기성분에 대하여 전자선 조사는 휘발성 향기성분의 변화에 크게 영향을 미치지 않는 것으로 판단되었다. 관능평가 실시 결과, 1 kGy 이하의 저선량으로 전자선 조사된 배의 기호도가 대조군보다 오히려 약간 높은 것으로 나타났으며 유의적인 차이는 없었다. 위의 결과를 토대로 신고배의 전자선 조사기술을 적용하기 위해서는 다양한 실험방법을 통한 지속적인 연구가 필요할 것으로 사료된다.

• Smart Structures and Systems
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• 제32권2호
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• pp.83-99
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• 2023

The temperature prediction approaches of three important locations in an operational longitudinal slab track-bridge structure by using three typical neural network methods based on the field measuring platform of four meteorological factors and internal temperature. The measurement experiment of four meteorological factors (e.g., ambient temperature, solar radiation, wind speed, and humidity) temperature in the three locations of the longitudinal slab and base plate of three important locations (e.g., mid-span, beam end, and Wide-Narrow Joint) were conducted, and then their characteristics were analyzed, respectively. Furthermore, temperature prediction effects of three locations under five various meteorological conditions are tested by using three neural network methods, respectively, including the Artificial Neural Network (ANN), the Long Short-Term Memory (LSTM), and the Convolutional Neural Network (CNN). More importantly, the predicted effects of solar radiation in four meteorological factors could be identified with three indicators (e.g., Root Means Square Error, Mean Absolute Error, Correlation Coefficient of R2). In addition, the LSTM method shows the best performance, while the CNN method has the best prediction effect by only considering a single meteorological factor.

• 한국전기전자재료학회논문지
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• 제13권7호
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• pp.551-556
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• 2000

We have investigated the effect of surface In composition with Si cell temperature on the In$_{0.1}$/Ga$_{0.9}$/As epilayers grown on GaAs substrates. The epilayers were grown by molecular beam epitaxy(MBE) method and were characterized by the pthotoreflectance(PR) measurements. The E$_{o}$ bandgap energies of In$_{0.1}$/Ga$_{0.9}$/As epilayers were observed at around 1.28 eV at room temperature, and the additional shoulder peaks appeared at the higher energies than E$_{o}$ with increase of Si doping concentrations. The intensity of the additional shoulder peak was decreased with lowering the measurement temperature and the peak disappeared with the increase of surface etching time. This results hows that In composition at surface of InGaAs epilayer is decreased with the increase of the doping cell temperature. We consider that the reason of the decrease of In composition at the surface should be due to In re-evaporation from the surface by radiation heat of Si doping cell.ell.ell.ell.

• Radiation Oncology Journal
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• 제15권3호
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• pp.251-254
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• 1997

목적 : 침윤성자궁경부암에서 단순자궁적출술을 시행하는 것은 통상적인 치료원칙에 배치된다. 본 연구는 침윤성자궁경부암에서 단순자궁적출술이 시행되었을 경우 방사선치료의 역할을 확인하기 위하여 시행되었다. 대상 및 방법 :침윤성자궁경부암환자로서 단순자궁적출을 시행받고 1989년 4월부터 1993년 12월까지 경상대학교병원 치료방사선과에서 방사선치료를 시행받은 19명의 환자를 대상으로 후향적 분석을 시행하였다. 연구대상의 연령의 중앙값은 49세이었고, 연구대상에 대한 추적기간의 중앙간은 46개월이었다. 방사선치료는 17명에서는 외부방사선조사만 시행되었고 절제연에 잔류암이 있었던 2명에서는 강내치료를 병용하였다. 결과 : 전체 4년 생존율은 $75\%$이었고, 4년 국소제어율은 $89\%$이었다. 2명에서 국소 및 원격재발이 있었고 2명에서 원격재발이 있었다. 결론 : 침윤성 자궁경부암에서 단순자궁적출술이 시행된 경우 방사선치료는 매우 적절한 후속조치가 됨을 확인할 수 있었다.

• 대한방사선기술학회지:방사선기술과학
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• 제21권2호
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• pp.36-42
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• 1998

Treatment of a large diseased area with electron often requires the use of two or more adjoining fields. In such cases, not only electron beam divergence and lateral scattering but also fields overlapping and separation may lead to significant dose inhomogeneities(${\pm}20%$) at the region of junction of fields. In this study, we made Acrylic Electron Wedges to improve dose inhomogeneities(${\pm}5%$) in these junction areas and to apply it to clinical practices. All measurements were made using 6, 9, 12, 16, 20 MeV Electron beams from a linear accelerator for a $10{\times}10\;cm$ field at 100cm of SSD. Adding a 1 mm sheet of acryl gradually from 1 mm to 15 mm acquires central axis depth dose beam profile and isodose curves in water phantom. As a result, for all energies, the practical range was reduced by approximately the same distance according to the acryl insert, e.g. a 1 mm thick acryl insert reduces the practical range by approximately 1 mm. For every mm thickness of acryl inserted, the beam energy was reduced to approximately 0.2 MeV. These effects were almost Independent of beam energy and field size. The use of Acrylic Electron Wedges produced a small increase(less than 3%) in the surface dose and a small increase(less than 1%) in X-ray contamination. For acryl inserts, thickness of 3 mm or greater, the penumbra width increased nearly linear for all energies and isodose curves near the beam edge were nearly parallel with the incident beam direction at the point of penumbra width($35\;mm{\sim}40\;mm$). We decide heel thickness and angle of the wedge at this point. These data provide the information necessary to design Acrylic Electron Wedge which can be used to improve dose uniformity at electron field junctions and it will be effectively applied to clinical practices.

• Radiation Oncology Journal
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• 제37권1호
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• pp.13-21
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• 2019

Purpose: Glioblastoma (GBM) carries a high propensity for in-field failure despite trimodality management. Past studies have failed to show outcome improvements with dose-escalation. Herein, we examined trends and outcomes associated with dose-escalation for GBM. Materials and Methods: The National Cancer Database was queried for GBM patients who underwent surgical resection and external-beam radiation with chemotherapy. Patients were excluded if doses were less than 59.4 Gy; dose-escalation referred to doses ≥66 Gy. Odds ratios identified predictors of dose-escalation. Univariable and multivariable Cox regressions determined potential predictors of overall survival (OS). Propensity-adjusted multivariable analysis better accounted for indication biases. Results: Of 33,991 patients, 1,223 patients received dose-escalation. Median dose in the escalation group was 70 Gy (range, 66 to 89.4 Gy). The use of dose-escalation decreased from 8% in 2004 to 2% in 2014. Predictors of escalated dose were African American race, lower comorbidity score, treatment at community centers, decreased income, and more remote treatment year. Median OS was 16.2 months and 15.8 months for the standard and dose-escalated cohorts, respectively (p = 0.35). On multivariable analysis, age >60 years, higher comorbidity score, treatment at community centers, decreased education, lower income, government insurance, Caucasian race, male gender, and more remote year of treatment predicted for worse OS. On propensity-adjusted multivariable analysis, age >60 years, distance from center >12 miles, decreased education, government insurance, and male gender predicted for worse outcome. Conclusion: Dose-escalated radiotherapy for GBM has decreased over time across the United States, in concordance with guidelines and the available evidence. Similarly, this large study did not discern survival improvements with dose-escalation.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.332-332
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• 2011

The extreme ultraviolet (EUV) radiation, whose wavelength is from 120 nm down to 10 nm, and the energy from 10 eV up to 124 eV, is widely utilized such as in photoelectron spectroscopy, solar imaging, especially in lithography and soft x-ray microscopy. In this study, we have investigated the plasma diagnostics as well as the debris characteristics between the two types of dense plasma focusing devices with coaxial electrodes of Mather and hypocycloidal pinch (HCP), respectively. The EUV emission intensity, electron temperature and plasma density have been investigated in these cylindrical focused plasma along with the debris characteristics. An input voltage of 5 kV has been applied to the capacitor bank of 1.53 uF and the diode chamber has been filled with Ar gas at pressure ranged from 1 mTorr and 180 mTorr. The inner surface of the cathode was covered by polyacetal insulator. The central anode electrode has been made of tin. The wavelength of the EUV emission has been measured to be in the range of 6~16 nm by a photo-detector (AXUV-100 Zr/C, IRD). The visible emission has also been measured by the spectrometer with the wavelength range of 200~1,100 nm. The electron temperature and plasma density have been measured by the Boltzmann plot and Stark broadening methods, respectively, under the assumption of local thermodynamic equilibrium (LTE).

• 폴리머
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• 제37권5호
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• pp.571-578
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• 2013

다양한 조성의 ethylene propylene diene rubber(EPDM)/polyamide12(PA12) 용융 혼합물에 전자선 조사를 함으로써 열가소성 탄성체(thermoplastic elastomer, TPE)의 특성을 보이는 소재를 제조하였다. EPDM과 PA12 상 사이의 상용화제로 말레산화 EPDM(mEPDM)을 첨가함으로써 EPDM/PA12 용융 혼합물의 기계적 물성을 향상시켰다. 또한 EPDM/PA12 용융 혼합물에 0~100 kGy의 전자선을 조사함으로써 EPDM 사슬간의 선택적인 가교 반응을 유도함과 동시에 PA12 상으로부터 용융 유동성을 확보할 수 있었다. 결과적으로 EPDM/PA12 용융 혼합물에 mEPDM을 첨가한 후 전자선을 25 kGy 조사함에 의하여 열가소성 용융 거동을 보이면서도 물성 및 탄성체 성질이 우수한 EPDM/PA12 용융 혼합물을 제조할 수 있었다.

• Radiation Oncology Journal
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• 제36권1호
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• pp.25-34
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• 2018

Purpose: This study aimed to evaluate the initial outcomes of proton beam therapy (PBT) for hepatocellular carcinoma (HCC) in terms of tumor response and safety. Materials and Methods: HCC patients who were not indicated for standard curative local modalities and who were treated with PBT at Samsung Medical Center from January 2016 to February 2017 were enrolled. Toxicity was scored using the Common Terminology Criteria for Adverse Events (CTCAE) version 4.0. Tumor response was evaluated using modified Response Evaluation Criteria in Solid Tumors (mRECIST). Results: A total of 101 HCC patients treated with PBT were included. Patients were treated with an equivalent dose of $62-92GyE_{10}$. Liver function status was not significantly affected after PBT. Greater than 80% of patients had Child-Pugh class A and albumin-bilirubin (ALBI) grade 1 up to 3-months after PBT. Of 78 patients followed for three months after PBT, infield complete and partial responses were achieved in 54 (69.2%) and 14 (17.9%) patients, respectively. Conclusion: PBT treatment of HCC patients showed a favorable infield complete response rate of 69.2% with acceptable acute toxicity. An additional follow-up study of these patients will be conducted.

• 방사선산업학회지
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• 제11권1호
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• pp.39-45
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• 2017

A cyclotron is a kind of particle accelerator that produces a beam of charged particles for the production of medical, industrial, and research radioisotopes. More than 30 cyclotrons are operated in Korea to produce $^{18}F$, an FDG synthesis at hospitals. A 30-MeV cyclotron was installed at ARTI (Advanced Radiation Technology Institute, KAERI) mainly for research regarding isotope production. In this study, we analyze and estimate the items of risk such as the problems in the main components of the cyclotron, the loss of radioactive materials, the leakage of coolant, and the malfunction of utilities, fires and earthquakes. To estimate the occurrence frequency in an accident risk assessment, five levels, i.e., Almost certain, Likely, Possible, Unlikely, and Rare, are applied. The accident consequence level is classified under four grades based on the annual permissible dose for radiation workers and the public in the nuclear safety law. The analysis of the accident effect is focused on the radioactive contamination caused by radioisotope leakage and radioactive material leakage of a ventilation filter due to a fire. To analyze the risks, Occupation Safety and Health Acts is applied. In addition, action plans against an accident were prepared after a deep discussion among relevant researchers. In this acts, we will search for hazard and introduce the risk assessment for the research 30-MeV cyclotron facilities of ARTI.