• 한국의학물리학회지:의학물리
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• 제34권4호
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• pp.48-54
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• 2023

Purpose: In this study, the dosimetric characteristics of lung stereotactic body radiotherapy (SBRT) plans using the new Halcyon system were analyzed to assess its suitability. Methods: We compared the key dosimetric parameters calculated for the Halcyon SBRT plans with those of a conventional C-arm linear accelerator (LINAC) equipped with a high-definition multileaf collimator (HD-MLC)-Trilogy Tx. A total of 10 patients with non-small-cell lung cancer were selected, and all SBRT plans were generated using the RapidArc technique. Results: Trilogy Tx exhibited significant superiority over Halcyon in terms of target dose coverage (conformity index, homogeneity index, D_{0.1 cc}, and D_95%) and dose spillage (gradient). Trilogy Tx was more efficient than Halcyon in the lung SBRT beam delivery process in terms of the total number of monitor units, modulation factor, and beam-on time. However, it was feasible to achieve a dose distribution that met SBRT plan requirements using Halcyon, with no significant differences in satisfying organs at risk dose constraints between both plans. Conclusions: Results confirm that Halcyon is a viable alternative for performing lung SBRT in the absence of a LINAC equipped with HD-MLC. However, extra consideration should be taken in determining whether to use Halcyon when the planning target volume setting is enormous, as in the case of significant tumor motions.

• 대한방사선치료학회지
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• 제27권1호
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• pp.45-52
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• 2015

목 적 : 전립선암의 방사선치료는 치료기법에 따라 주요장기와 정상조직의 선량분포에 차이가 나타난다. 본 연구에서는 전립선암 환자의 수술 후 방사선치료 시 직장풍선을 삽입한 환자에게 회전수를 달리한 용적변조회전치료(volumetric modulated arc therapy, VMAT)계획과 세기변조방사선치료(intensity modulated radiation therapy, IMRT)계획을 각각 수립하여 선량분포 특성을 비교하고 치료의 효율성을 평가하고자 한다. 대상 및 방법 : 본원에서 전립선암 수술 후 방사선 치료를 시행한 10명의 환자를 대상으로 하였다. 직장풍선을 삽입한 환자의 CT영상을 3 mm 두께로 획득하고 Eclipse (Ver 11.0, Varian, Palo Alto, USA)를 사용하여 HD120MLC가 장착된 Truebeam STx (Varian, Palo Alto, USA)의 10 MV 에너지를 적용하였다. 환자마다 1 Arc, 2 Arc VMAT계획과 7조사면의 IMRT계획을 수립하였으며 각 치료계획의 선량체적제한과 plan normalization 값은 동일하게 적용하였다. 수립된 세 가지 치료계획을 평가하기위해 PTV의 coverage, conformity index (CI), homogeneity index (HI)를 비교하였고, PTV주변 정상조직의 선량퍼짐정도를 알아보기 위해 50% 등선량체적과 PTV체적의 비($R_{50%}$)를 산출하였다. 결정장기 (organ at risk, OAR)에서는 직장의 $D_{25%}$와 방광의 $D_{mean}$을 비교하였고 치료의 효율성을 평가하기 위해서 총 MU와 조사시간을 측정하였으며, 각 평가항목별 결과는 환자 10명의 평균값으로 비교분석하였다. 추가적으로 선량전달 정확도를 검증하기 위해 EPID를 이용한 portal dosimetry를 진행하였다. 결 과 : 각 치료계획에서 나타난 PTV coverage와 HI의 차이는 크지 않았지만 CI는 1A-VMAT, 2A-VMAT, 7F-IMRT에서 각각 1.036, 1.035, 1.230으로 VMAT에 비해 7F-IMRT가 높았고(p=0.00), $R_{50%}$는 3.083, 3.054, 3.991로 2A-VMAT이 제일 낮았고 7F-IMRT에서 가장 높게 나타났다(p=0.00). 치료계획에 따른 직장의 $D_{25%}$는 VMAT에서 비슷했지만 7F-IMRT가 약 7% 높게 나타났고(p=0.02), 방광의 $D_{mean}$은 큰 차이가 없었다(P>0.05). 총 MU는 1A-VMAT, 2A-VMAT, 7F-IMRT에서 각각 494.7, 479.7, 757.9로 7F-IMRT가 가장 많았고(p=0.00), 조사시간은 65.2초, 133.1초, 145.5초로 1A-VMAT이 확연히 짧았다(p=0.00). portal dosimetry 검증에서는 모든 치료계획에서 99.5% 이상의 gamma pass rate(2 mm, 2%)을 보였다(P=0.00). 결 론 : 본 연구결과 직장풍선을 삽입한 전립선암 환자의 수술 후 방사선치료 시, 치료기법에 따른 PTV coverage의 차이는 크지 않았지만 1A, 2A-VMAT이 7F-IMRT에 비해 정상조직과 직장선량을 낮추는데 효과적이었다. VMAT중에서는 $R_{50%}$와 MU가 2A-VMAT에서 다소 낮았지만 조사시간이 짧은 1A-VMAT이 치료에 더 효율적이며 환자의 치료 중 움직임 또한 줄일 수 있을 것으로 사료된다.

• 환경영향평가
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• 제21권5호
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• pp.801-811
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• 2012

For biodiversity conservation, Biological Impact Assessment is very important. The focus of the study is to enhance efficient Environment Impact Assessment(EIA) based on collecting existing information of endangered species covering the status survey, estimation of effects and reducing methods. Habitat Suitability Index(HSI) can be applicable to Ecological Impact Assessment and finding various reducing methods based on estimating effects. For this study, the EIA report of Samjang - Sanchung highway construction was chosen as an example and Prionailurus bengalensis euptilura as an endangered species was chosen to assess the ecosystem impact on road construction. Water, road, ground coverage, slope, altitude as variables of habitat were weighted and final HSI map was calculated using Arc map and Arc view. Through comparing of before and after HSI, quantitative estimating on effects was possible to minimize impact of road construction to wildlife habitat.

• 수산해양교육연구
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• 제27권1호
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• pp.300-307
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• 2015

Seasonal variation in marine macroalgal community structure was examined at the intertidal zones of Geumgap, Jindo, Korea, from October 2013 to August 2014. In total, 56 macroalgal species were identified, including 9 green, 12 brown, and 35 red algae. Annual seaweed biomass was 548.96 g wet wt. /$m^2$ with seasonal range between 371.08 g wet wt. /$m^2$ at summer and 32.91 g wet wt. /$m^2$ at winter. The dominant seaweed in terms of biomass was Sargassum thunbergii and subdominant species were Gelidium elegans, Sargassum fusiforme, and Ishige okamurae. The vertical distribution of seaweeds from the upper to lower intertidal zones was Gloiopeltis spp., Ulva spp.- S. thunbergii, S. fusiforme, Ishige okamurae - S. thunbergii, S. fusiforme, G. elegans. Annual seaweed coverage, richness index (R), evenness index (J'), and diversity index (H') values were 27.95%, 6.10, 0.38, and 1.38, respectively. Coarsely branched form was the most dominant functional group in terms of species number and biomass among benthic macroalgal species.

• 대한안전경영과학회지
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• 제17권1호
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• pp.125-130
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• 2015

Techniques, using physical wedge filter and using dynamic wedge filter and FIF(Field in Field) and ISCT(Irregular Surface Compensating Technique), have been developed according to progress of radiation therapy of breast cancer. Measurement of dose was done to judge the usefulness of technique using three cases, non tissue loss after breast conserving operating and tissue loss after breast conserving operating and mastectomy. Dose indexes of breast tissue, CI (Conformity Index), HI (Homogeneity Index) and QOC (Quality of Coverage), dose index of skin, or dose indexes of lung, volume of 50 percent dose and 20 percent dose were estimated and compared. Using dynamic wedge filter is useful plan at non tissue loss allowing for high dose of lung. FIF and ISCT are useful plan at tissue loss. ISCT is useful plan at mastectomy. Henceforth, we need to apply to valid plan and body type and thorax size.

• 한국세라믹학회지
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• 제31권2호
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• pp.206-212
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• 1994

Effects of the film deposition process parameters on the properties such as deposition rate, etch rate, refractive index, stress and step coverage of plasma enhanced chemical vapor deposited (PECVD) tetraethylorthosilicate glass (TEOS) SiO2 film were investigated and analysed using SEM, FTIR and SIMS techniques. Increasing TEOS flow or decreasing O2 flow increased the deposition rate and the compressive stress of the oxide film but produced a less denser film. The deposition rate decreased owing to the decrease in the sticking coefficient of the TEOS and the O2 molecules onto the substrate Si with increasing the substrate temperature. Increasing the substrate temperature produced a denser film with a lower etch rate and the higher refractive index by lowering SiOH and moisture contents. Increasing the rf power increases the ion bombardment energy. This increase in energy, in turn, increases the deposition rate and tends to make the film denser. No appreciable changes were found in the deposition rate but the refractive index and the stress of the film decreased with increasing the deposition pressure. The carbon content in the plasma TEOS CVD oxide film prepared under our standard deposition conditions were very low according to the SIMS analysis results.

• Nuclear Engineering and Technology
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• 제54권10호
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• pp.3816-3823
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• 2022

This work analyzed the dosimetric difference between the intensity modulated radiotherapy (IMRT), partial/single/double-arc volumetric modulated arc therapy (PA/SA/DA-VMAT) techniques in treatment planning for treating more than one target of lung cancer at different isocenters. IMRT and VMAT plans at different isocenters were created systematically using a Harold heterogeneous lung phantom. The conformity index (CI), homogeneity index (HI), gradient index (GI), dose-volume histogram and mean and maximum dose of the PTV were calculated and analyzed. Furthermore, the dose-volume histogram and mean and maximum doses of the OARs such as right lung, contralateral lung and non GTV were determined from the plans. The IMRT plans showed the superior target dose coverage, higher mean and maximum values than other VMAT techniques. PA-VMAT technique shows more lung sparing and DA-VMAT increases the V_5/10/20 values of contralateral lung than other VMAT and IMRT techniques. The IMRT technique achieves highly conformal dose distribution to the target than other VMAT techniques. Comparing to the IMRT plans, the higher V_5/10/20 and mean lung dose were observed in the contralateral lung in the DA-VMAT.

• 대한전자공학회논문지
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• 제22권2호
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• pp.90-96
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• 1985

PECVD장비를 사용하여 PSG를 증착하고 막의 유전 및 보호막 특성을 조사하였다. X-선 형광분석으로 PSG내의 인 농도를 분석한 결과 약 8m/o에서 포화되었다. 인 함량에 대한 PSC의 적외선 홉수율, 식각속도 및 시트저항등의 변화도 비교하였다. APCVD와 PECV각에 대한 유전특성, 스텝 커버리지, 크랙저항과 게터링효과를 검토하였다. PECVD산화막은 비중 2.4g/㎤, 굴절율 1.53, 항복전장 11-13MV/cm의 값을 가졌고 크랙저항도 APCVD산화막 보다 우수하였다 2m/o의 인을 포함하는 PECVD PSG의 경우 양호한 스텝 커버리지와 게터링효과를 보였다. 공정변수에 대한 일련의 실험을 통하여 PECVD PSC 공정으로 보다 개선된 특성의 보초막을 얻을 수 있었다.

• 한국산림과학회지
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• 제94권5호통권162호
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• pp.338-341
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• 2005

This study was conducted to describe the differences in artificial nest boxes use of tits between deciduous and coniferous forests at 2nd campus of Chung-Ang University ($37^{\circ}00^{\prime}04^{{\prime}{\prime}}N$, $127^{\circ}13^{\prime}96^{{\prime}{\prime}}E$), Ansung, Korea from January to August 2005. Tree species richness, tree species diversity index (H') and total basal areas were higher in deciduous forest than in coniferous forest. High, middle, low and understory canopy layers were more developed in deciduous forest, except the coverage of bush-ground layer. Varied tit Parus varius, marsh tit P. palustris and great tit P. major used the artificial nest boxes in this study. Number of breeding pairs of tits used artificial nest boxes, clutch size, and weight and size of eggs were higher in deciduous forest than in coniferous forest. The differences in habitat structure between study sites are very likely to have influenced how breeding birds used the available habitat. Artificial nest boxes could be used as management and conservation tool for birds, particularly in areas, where the availability of natural cavities and coverage of higher layer are limited.

• Archives of Plastic Surgery
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• 제49권6호
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• pp.745-749
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• 2022

Background Soft tissue defects of the multiple finger present challenges to reconstruction surgeons. Here, we introduce the use of a lateral arm free flap and syndactylization for the coverage of multiple finger soft tissue defects. Methods This retrospective study was conducted based on reviews of the medical records of 13 patients with multiple soft tissue defects of fingers (n = 33) that underwent temporary syndactylization with a microvascular lateral arm flap for temporary syndactylization from January 2010 to December 2020. Surgical and functional outcomes, times of flap division, complications, and demographic data were analyzed. Results Middle fingers were most frequently affected, followed by ring and index fingers. Mean patient age was 43.58 years. The 13 patients had suffered 10 traumas, 2 thermal burns, and 1 scar contracture. Release of temporary syndactyly was performed 3 to 9 weeks after syndactylization. All flaps survived, but partial necrosis occurred in one patient, who required a local transposition flap after syndactylization release. The mean follow-up was 15.8 months. Conclusion Coverage of multiple finger defects by temporary syndactylization using a free lateral arm flap with subsequent division offers an alternative treatment option.