• Radiation Oncology Journal
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• 제34권3호
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• pp.186-192
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• 2016

Purpose: To determine whether large rectal volume on planning computed tomography (CT) results in lower tumor regression grade (TRG) after neoadjuvant concurrent chemoradiotherapy (CCRT) in rectal cancer patients. Materials and Methods: We reviewed medical records of 113 patients treated with surgery following neoadjuvant CCRT for rectal cancer between January and December 2012. Rectal volume was contoured on axial images in which gross tumor volume was included. Average axial rectal area (ARA) was defined as rectal volume divided by longitudinal tumor length. The impact of rectal volume and ARA on TRG was assessed. Results: Average rectal volume and ARA were 11.3 mL and $2.9cm^2$. After completion of neoadjuvant CCRT in 113 patients, pathologic results revealed total regression (TRG 4) in 28 patients (25%), good regression (TRG 3) in 25 patients (22%), moderate regression (TRG 2) in 34 patients (30%), minor regression (TRG 1) in 24 patients (21%), and no regression (TRG0) in 2 patients (2%). No difference of rectal volume and ARA was found between each TRG groups. Linear correlation existed between rectal volume and TRG (p = 0.036) but not between ARA and TRG (p = 0.058). Conclusion: Rectal volume on planning CT has no significance on TRG in patients receiving neoadjuvant CCRT for rectal cancer. These results indicate that maintaining minimal rectal volume before each treatment may not be necessary.

• 한국산림과학회지
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• 제106권4호
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• pp.473-479
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• 2017

본 연구는 유실수, 특용수, 산채 및 고로쇠 등을 주업으로 임업만 생산했을 경우와 자연순환농법으로 닭을 방사하여 키우는 산지양계와 결합한 복합경영일 경우의 조수입이 어느 정도 향상되었는지를 분석하였다. 연구대상지는 충청북도 충주시, 경상북도 경산시, 강원도 화천군에 위치하고 있는 3곳의 산지양계 복합경영 현장실연 임가이다. 그리고 현장 면담조사를 통해 2015년도 기준의 경영비와 조수입을 조사하여 산지양계의 비용구조와 경영성과를 비교 분석하였다. 연구결과, 충주는 조수입이 25,608,000원, 경영비가 20,217,571원으로 소득은 5,390,429원으로 분석되었고, 경산은 조수입이 33,950,000원, 경영비가 18,655,714원으로 소득은 15,494,286원인 것으로 나타났다. 화천은 조수입이 31,850,000원, 경영비가 13,143,000원으로 소득은 18,707,000원이었다. 그리고 판매량과 비용이 일치하는 손익분기 판매량은 충주는 617마리, 경산은 125마리, 화천은 63마리로 나타났다. 1마리당 가격에서 차지하는 원가율은 충주는 79%를 차지하였고, 경산은 55%, 화천은 41%를 차지하였고 이에 따른 마진율은 충주는 21%, 경산은 45%, 화천은 59%로 나타났다. 또한 산지양계복합경영의 소득효과는 조수입 기준으로 평가한 결과, 임업만 주업으로 할 때 보다 충주가 16%, 경산이 18% 그리고 화천이 11%로 증가한 것으로 나타났다.

• Journal of Advanced Marine Engineering and Technology
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• 제34권1호
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• pp.53-61
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• 2010

In the present study, a laminar natural convection flow of $H_2O$-Cu nanofluid in a two dimensional enclosure has been investigated using a thermal lattice Boltzmann approach with the Bhatnagar-Gross-Krook (BGK) model. The effect of suspended nanoparticles on the fluid flow and heat transfer process have been studied for different controlling parameters such as particle volume fraction ($\Phi$), Rayleigh number (Ra). For this investigation the Rayleigh number changes from 104 to 106 and volume fraction varied from 0 to 10% with three different particle diameters (dp), say 10 nm, 20 nm and 40 nm. It is shown that increasing the Rayleigh number (Ra) and the volume fraction of nanofluid causes an increase of the effective heat transfer rate in terms of average Nusselt number (Nu) as well as the thermal conductivity of nanofluid. On the other hand, increasing the particle diameter causes the decrease of the heat transfer rate and thermal conductivity. The result of the analysis are compared with experimental and numerical data both for pure and nanofluids and it is seen a relatively good agreement.

• Radiation Oncology Journal
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• 제35권2호
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• pp.180-184
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• 2017

Patients with locally advanced lung cancer and very limited pulmonary function (forced expiratory volume in 1 second $[FEV1]{\leq}1L$) have dismal prognosis and undergo palliative treatment or best supportive care. We describe two cases of locally advanced node-positive non-small cell lung cancer (NSCLC) patients with very limited lung function treated with induction chemotherapy and moderate hypofractionated image-guided radiotherapy (Hypo-IGRT). Hypo-IGRT was delivered to a total dose of 45 Gy to the primary tumor and involved lymph nodes. Planning was based on positron emission tomography-computed tomography (PET/CT) and four-dimensional computed tomography (4D-CT). Internal target volume (ITV) was defined as the overlap of gross tumor volume delineated on 10 phases of 4D-CT. ITV to planning target volume margin was 5 mm in all directions. Both patients showed good clinical and radiological response. No relevant toxicity was documented. Hypo-IGRT is feasible treatment option in locally advanced node-positive NSCLC patients with very limited lung function ($FEV1{\leq}1L$).

• Asian Pacific Journal of Cancer Prevention
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• 제15권17호
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• pp.7371-7375
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• 2014

Background: Concurrent chemo-radiotherapy is the recommended standard treatment modality for patients with locally advanced lung cancer. The purpose of three-dimensional conformal radiotherapy (3DCRT) is to minimize normal tissue damage while a high dose can be delivered to the tumor. The most common dose limiting side effect of thoracic RT is radiation pneumonia (RP). In this study we evaluated the relationship between dose-volume histogram parameters and radiation pneumonitis. This study targeted prediction of the possible development of RP and evaluation of the relationship between dose-volume histogram (DVH) parameters and RP in patients undergoing 3DCRT. Materials and Methods: DVHs of 41 lung cancer patients treated with 3DCRT were evaluated with respect to the development of grade ${\geq}2$ RP by excluding gross tumor volume (GTV) and planned target volume (PTV) from total (TL) and ipsilateral (IPSI) lung volume. Results: Were admitted statistically significant for p<0.05. Conclusions: The cut-off values for V5, V13, V20, V30, V45 and the mean dose of TL-GTV; and V13, V20,V30 and the mean dose of TL-PTV were statistically significant for the development of Grade ${\geq}2$ RP. No statistically significant results related to the development of Grade ${\geq}2$ RP were observed for the ipsilateral lung and the evaluation of PTV volume. A controlled and careful evaluation of the dose-volume histograms is important to assess Grade ${\geq}2$ RP development of the lung cancer patients treated with concurrent chemo-radiotherapy. In the light of the obtained data it can be said that RP development may be avoided by the proper analysis of the dose volume histograms and the application of optimal treatment plans.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2000년도 제31회 춘계학술대회
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• pp.263-268
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• 2000

The fretting damage of the contact between Zircaloy-4 and Inconel 600 have Investigated. A fretting wear tester was designed to be suitable for this fretting test. In this study, the number of cycles, slip amplitude and normal load were selected as main factors of fretting wear. As the result of this research the wear volume increased with the increase of loads, slip amplitudes and the number of cycles and was more affected by slip amplitudes rather than by load. According to SEM, stick, partial slip, gross slip were observed on the surface of both specimens and wavy worn surfaces as the typical fretting damage were also Investigated due to accumulation of plastic flow.

• Smart Structures and Systems
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• 제17권6호
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• pp.1087-1105
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• 2016

Traffic load and volume is one of the most important physical quantities for bridge safety evaluation and maintenance strategies formulation. This paper aims to conduct the statistical analysis of traffic volume information and the multimodal modeling of gross vehicle weight (GVW) based on the monitoring data obtained from the weigh-in-motion (WIM) system instrumented on the arch Jiubao Bridge located in Hangzhou, China. A genetic algorithm (GA)-based mixture parameter estimation approach is developed for derivation of the unknown mixture parameters in mixed distribution models. The statistical analysis of one-year WIM data is firstly performed according to the vehicle type, single axle weight, and GVW. The probability density function (PDF) and cumulative distribution function (CDF) of the GVW data of selected vehicle types are then formulated by use of three kinds of finite mixed distributions (normal, lognormal and Weibull). The mixture parameters are determined by use of the proposed GA-based method. The results indicate that the stochastic properties of the GVW data acquired from the field-instrumented WIM sensors are effectively characterized by the method of finite mixture distributions in conjunction with the proposed GA-based mixture parameter identification algorithm. Moreover, it is revealed that the Weibull mixture distribution is relatively superior in modeling of the WIM data on the basis of the calculated Akaike's information criterion (AIC) values.

• Neonatal Medicine
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• 제25권4호
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• pp.186-190
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• 2018

Esophageal atresia (EA) with proximal tracheoesophageal fistula (TEF; gross type B) is a rare defect. Although most patients have long-gap EA, there are still no established surgical guidelines. A premature male infant with symmetric intrauterine growth retardation (birth weight, 1,616 g) was born at 35 weeks and 5 days of gestation. The initial diagnosis was pure EA (gross type A) based on failure to pass an orogastric tube and the absence of stomach gas. A "feed and grow" approach was implemented, with gastrostomy performed on postnatal day 2. A fistula was detected during bronchoscopy for recurrent pneumonia; thus, we confirmed type B EA and performed TEF excision and cervical end esophagostomy. As the infant's stomach volume was insufficient for bolus feeding after reaching a body weight of 2.5 kg, continuous tube feeding was provided through a gastrojejunal tube. On the basis of these findings, esophageal reconstruction with gastric pull-up was performed on postnatal day 141 (infant weight, 4.7 kg), and he was discharged 21 days postoperatively. At 12 months after birth, there was no catch-up growth; however, he is currently receiving a baby food diet without any complications. In patients with EA, bronchoscopy is useful for confirming TEF, whereas for those with long-gap EA with a small stomach volume, esophageal reconstruction with gastric pull-up after continuous feeding through a gastrojejunal tube is worth considering.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.160-162
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• 2017

고무탄성체가 연료와 접촉하면 저분자량의 고무성분이나 첨가제 등이 연료에 의해 용출되면서 고무의 물성을 변화시키고 연료의 물성에도 영향을 미치게 된다. 본 연구에서는 고무탄성체 중 밀봉재로 사용되는 고무 오링이 연료와 장기간 접촉하고 있을 때 고무 오링의 수명을 예측하기 위해 접촉 연료의 부피와 온도, 저장시간에 따라 고무 오링의 물성치로 무게, 부피, 두께, 경도, 인장강도, 신장율 및 영구압축줄음율 측정하여 변화정도를 측정하였다. 또한 연료의 GC분석을 통해 순도변화를 분석하고 총발열량을 측정하여 고무 접촉에 의한 연료의 열화정도를 측정하였다. 이러한 측정결과는 수명을 예측하기 위한 기본 자료로 사용할 예정이다.

• 대한방사선기술학회지:방사선기술과학
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• 제46권6호
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• pp.527-533
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• 2023

The purpose of this study is to evaluate the clinical risk of spinal radiosurgery by calculating the dose difference due to dose calculation algorithm and multi-leaf collimator positioning error. The images acquired by the CT simulator were recalculated by correcting the multi-leaf collimator position in the dose verification program created using MATLAB and applying stoichiometric calibration and Monte Carlo algorithm. With multi-leaf collimator positioning error, the clinical target volume (CTV) showed a dose difference of up to 13% in the dose delivered to the 95% volume, while the gross tumor volume (GTV) showed a dose difference of 9%. The average dose delivered to the total volume showed dose variation from -8.9% to 9% and -10.1% to 10.2% for GTV and CTV, respectively. The maximum dose delivered to the total volume of the spinal cord showed a dose difference from -14.2% to 19.6%, and the dose delivered to the 0.35 ㎤ volume showed a dose difference from -15.5% to 19.4%. In future research, automating the linkage between treatment planning systems and dose verification programs would be useful for spinal radiosurgery.