• Korean Journal of Radiology
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• 제25권2호
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• pp.199-209
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• 2024

Objective: This study aimed to compare therapeutic efficacy and technical outcomes between adjustable electrode (AE) and conventional fixed electrode (FE) for radiofrequency ablation (RFA) of benign thyroid nodules. Materials and Methods: Between 2013 and 2021, RFA was performed on histologically proven benign thyroid nodules. For the AE method, AE length ≥ 1 cm with higher power and < 1 cm with lower power were utilized for ablating feeding vessels and nodules, especially those near anatomical structures, respectively. The therapeutic efficacy (volume reduction rate [VRR], complication rate, and regrowth rate) and technical outcomes (total energy delivery, ablated volume/energy, RFA time, and ablated volume/time) of FE and AE were compared. Continuous parameters were compared using a two-sample t-test or Mann-Whitney U test, and categorical parameters were compared using a chi-squared test or Fisher's exact test. Results: A total of 182 nodules (FE: 92 vs. AE: 90) in 173 patients (mean age ± standard deviation, 47.0 ± 14.7 years; female, 90.8% [157/173]; median follow-up, 726 days [interquartile range, 441-1075 days]) were analyzed. The therapeutic efficacy was comparable, whereas technical outcomes were more favorable for AE. Both electrodes demonstrated comparable overall median VRR (FE: 92.4% vs. AE: 84.9%, P = 0.240) without immediate major complications. Overall regrowth rates were comparable between the two groups (FE: 2.2% [2/90] vs. AE: 1.1% [1/90], P > 0.99). AE demonstrated a shorter median RFA time (FE: 811 vs. AE: 627 seconds, P = 0.009). Both delivered comparable median energy (FE: 42.8 vs. AE: 29.2 kJ, P = 0.069), but AE demonstrated higher median ablated volume/energy and median ablated volume/time (FE: 0.2 vs. AE: 0.3 cc/kJ, P < 0.001; and FE: 0.7 vs. AE: 1.0 cc/min, P < 0.001, respectively). Conclusion: Therapeutic efficacy between FE and AE was comparable. AE demonstrated better technical outcomes than FE in terms of RFA time, ablated volume/energy, and ablated volume/time.

• 대한영양사협회학술지
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• 제28권1호
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• pp.19-29
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• 2022

This study examined the impact of perceived volume on satiety using 400 g kimchi fried rice in a normal rice bowl (Normal-400), 300 g kimchi fried rice in an augmented rice bowl with an elevated bottom (Illusion-300 and 300 g kimchi fried rice in a normal rice bowl (Normal-300). Thirty-six healthy women took part in this study once a week for three weeks. The Normal-400 (1st week), Illusion-300 (2nd week), and Normal-300 (3rd week) bowls were used to served kimchi fried rice to the same participants over three consecutive weeks. After each lunch, the consumption volume of fried rice, perception volume, and satiety rate were measured. The consumption volume of the fried rice was 313.8 g with the Normal-400, 248.9 g with the Illusion-300 and 240.2 g with the Normal-300. The perceived volume on an estimated five-point scale was 4.0 with the Normal-400, 4.1 with the Illusion-300 and 2.4 with the Normal-300. We compared the post-meal satiety of perceptually equal but quantitatively different amounts of food served in two different bowls (Normal-400 vs Illusion-300) and found that the participants felt equally full with both bowls despite having consumed significantly more food from the Normal-400. We also compared the post-meal satiety of perceptually different but quantitatively equal amounts of food in two different bowls (Illusion-300 vs Normal-300) and discovered that the subjects felt significantly fuller with the Illusion-300 although similar amounts of food were consumed from the two bowls. These two comparisons showed that visual cues play a critical role in determining satiety and that perceived volume is perhaps more important than the actual volume of consumed food, while in determining the level of fullness.

• 무역학회지
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• 제42권2호
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• pp.277-296
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• 2017

전 세계 수출입 물동량 중 95% 이상이 해상 수송되고 있다. 이처럼 세계 무역에서 해상 수송이 차지하는 비중이 매우 높다는 점에 주목하여, 본 연구는 해상 물동량과 세계 경제(세계 GDP) 간의 회귀분석을 수행함으로써 상관관계를 추정하였다. 즉, 패널 데이터 분석과 확률효과 모형 분석을 통해 품목별 해상 물동량이 세계 경제 성장에 어떤 영향을 미치는지 실증 분석하였다. 분석 과정에서 해상 물동량을 10개 품목별로 분류하고, 해당 품목의 무역량 변화에 따라 세계 GDP가 얼마만큼 영향을 받는지 추정하였다. 이와 더불어 그랜저 인과성 검정을 수행하여 해상 물동량과 세계 GDP 변수 간의 선후 관계를 검증하고, LR(Likelihood ratio) 검정을 실시하여 확률효과 모형을 통해 회귀분석 하였다. 본 연구의 분석 결과는 정부의 무역 관련 정책을 수립하는 데 많은 도움을 줄 것으로 기대된다.

• 한국생활과학회지
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• 제22권6호
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• pp.723-736
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• 2013

To examine the quality characteristics of bread made of different amounts of chia seed powder, a functional food ingredient, this study made bread by adding chia seed powder by 1%, 3%, and 5% of the flour weight. When bread dough properties were determined using mixograph, all doughs were appropriate for bread-making. In the evaluation of fermentation rate, the dough with 3% of chia seed powder CS 3 showed the most favorable fermentation rate during the first 60-min fermentation of the bread. According to CrumbScan, the fineness of bread pores were higher in control group than bread loaves containing chia seed powder. The volume of bread in control group was significantly lower than those of other experimental groups. The volume and specific volume were highest when chia seed powder was added by 3%. According to preference analysis, appearance and taste was best in CS 3, showing the highest overall score in preference. Therefore, the optimum amount of chia seed powder is identified to be 3% in bread-making.

• 한국분무공학회지
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• 제2권2호
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• pp.24-34
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• 1997

This paper describes the investigation of combustion characteristics of gasoline-methanol blend in constant volume combustion chamber. A constant volume combustion chamber was used to elucidate a basic combustion characteristics and the premixer was installed to control temperature and equivalence ratio. And the maximum pressure, combustion duration and flame propagation according to the evaporation rate were measured to determine the optimal temperature range for evaporating a blend fuel. These experimental results indicate that the combustion characteristics such as combustion chamber pressure and combustion were deteriorated by decreasing surrounding temperature of fuel. These experimental results indicate that the combustion characteristics such as combustion chamber pressure and combustion were deter orated by decreasing surrounding temperature of fuel injected. It was also found that the overall gasification process for methanol blend fuel was influenced by a combustion chamber temperature rather than a premixer temperature.

• 한국응용과학기술학회지
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• 제28권2호
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• pp.178-184
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• 2011

The analysis of reaction kinetics provided that the reaction order was the $1^{st}$ of triglyceride and the rate constant was 0.067 $min^{-1}$. The transesterification of camelina oil using 0.6 wt% mixed catalyst which consists of 40 v/v% of potassium hydroxide (1 wt%) and 60 v/v% of tetra methyl ammonium hydroxide (0.8 wt%), was carried out at $65^{\circ}C$ on the tubular reactor packed with static mixer. The conversion was shown to be 95.5% at the 6:1 molar ratio of methanol to oil, flow rate of feed of 3.0 mL/min and 24 of element of static mixer. The volume of washing water emitted by 0.6 wt% mixed catalyst was the half of the volume emitted by 1 wt% potassium hydroxide.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(III)
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• pp.345-350
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• 2003

The inside of EMU is supplied with the cooling air from air-conditioner and the fresh air from exterior through the air-conditioner duct which is one of the air conditioning system. The shape of air-conditioner duct is a major factor in determining the air-conditioning efficiency, thermal comfort and energy efficiency. Therefore, this study is to understand the flow characteristics in the air-conditioner duct by three dimensional numerical simulation. The air-conditioner duct was calculated for the design volume flow rate, $2,726\;m^3/h/unit$. From the result of calculation and measurement, the velocity at diffuser outlet presented good agreement in general. [n this present study, the calculation was also performed for three volume flow rate(1,800, 2,200, 3,000 $m^3/h/unit$) and total pressure characteristic curve with volume flow rate was presented.

• 한국자동차공학회논문집
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• 제11권4호
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• pp.29-36
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• 2003

A cylindrical constant volume combustion chamber was used to investigate the flow characteristics at spark plug and the combustion characteristics of inhomogeneous charge methane-air mixture under several parameters. The flow characteristics such as mean velocity and turbulence intensity was analyzed by hot wire anemometer. Combustion pressure development measured by piezoelectric pressure transducer was used to investigate the effect of initial charge pressure, excess air ratio and ignition times on combustion pressure and combustion duration. Mean velocity and turbulence intensity had the maximum value at 200 or 300ms and then decreased to beneath 0.05m/s gradually at 3 seconds. Second mixture is accompanied by an increase in the combustion rate, and that the higher the mass which is added in the second stage injection, the faster the burn rate.

• 한국산림과학회지
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• 제97권6호
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• pp.627-633
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• 2008

본 연구는 국가 산림자원조사 자료를 이용하여 우리나라에 분포하는 주요 참나무류 수종의 영급별 재적생장률을 추정하고 수종간의 통계적 차이와 연관성을 분석하고자 하였다. 또한 분석된 결과를 토대로 현재 사용되고 있는 단목재적식의 적합성 및 갱신 필요성을 점검하는 한편, 임령에 따른 수종별 재적생장률을 예측할 수 있는 모델을 개발하고자 하였다. 본 연구에서 사용된 주요 참나무류 수종은 상수리나무, 갈참나무, 졸참나무, 굴참나무, 떡갈나무, 그리고 신갈나무의 6개 수종이다. 이들 수종에 대해서 표본 조사된 직경생장량을 근거로 직경생장률과 수고생장률을 산출하였으며, 이를 이용하여 최종적으로 재적생장률을 추정하였다. 추정된 재적생장률이 수종별 영급별로 차이가 있는지를 점검하기 위해 분산분석 및 Duncan의 다중검정을 실시한 결과, 참나무류 6개 수종의 영급별 재적생장률은 수종에 따라 다소 차이는 있지만, II영급에서 10% 내외의 높은 생장률을 보이다가 III영급에서는 6% 내외로 낮아지고 영급이 더 커짐에 따라 생장률은 감소하는 것으로 나타났다. 수종별로는 상수리나무, 갈참나무, 졸참나무의 3개 수종의 생장률이 상대적으로 높았으며, 굴참나무, 떡갈나무, 신갈나무는 생장률이 낮은 것으로 분석되었다. 6개 대상수종들을 생장률이 높은 그룹과 낮은 그룹으로 나누고 그 생장률의 차이를 분석한 결과, 그룹 내에서는 큰 차이가 없었으나, 그룹 간에는 뚜렷한 차이가 있는 것으로 나타났다. 이러한 결과에 따라 각 그룹별 재적생장률 예측모델도 개발하였다. 본 연구의 결과는 기존의 참나무류 단목재적식을 사용하기 위해서 적용하였던 수종구분과는 다소 차이가 있는 것으로서 기존 단목재적식을 개선할 여지가 있음을 보여주고 있다.

• 무역학회지
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• 제48권4호
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• pp.47-66
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• 2023

본 연구는 중국의 대외무역정책 조치가 중국에 미치는 영향을 살펴보고자 하며 중국의 양자 무역이 실질실효환율의 움직임에 크게 영향을 받는다는 것으로 나타났다. 또한, 총무역흐름과 환율변동의 관계를 분석한 결과 실질환율의 하락이 중국의 수출량을 증가시키고 수입량을 소폭 감소시키는 것으로 나타났다. 또한 중국의 수출량은 환율수준에 비해 환율변동성에 대한 민감도가 높은 것으로 나타났으며, 나아가 세분화된 무역흐름에 대한 실증결과는 상품마다 환율변동에 따라 상이한 영향을 받고 있음을 시사하고 있다. 자본재와 소비재는 서로 다른 가공 단계에 있으므로 환율 하락으로 인해 수출입에 부정적인 영향을 미치지 않은 것으로 나타났다.