• Advances in aircraft and spacecraft science
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• 제10권6호
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• pp.555-572
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• 2023

Airplanes in flight collide with raindrops, and the leading edges of the airframe can be damaged when colliding with raindrops. A single waterjet testing platform was created to study rain erosion damage. Carbon fiber samples with three types of skins were studied and the mechanical properties were measured using a nanoindentation instrument. The research results show that the impact force on the sample increases with the continuous increase in the impact speed of raindrops, which leads to an increase in the damage area. Sheathing with low surface roughness is more damaged than other sheathings due to its rougher surface, and the result proves that surface roughness has a more significant effect on rain erosion damage to sheathings compared to their hardness.

• 한국간담췌외과학회지
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• 제28권3호
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• pp.325-336
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• 2024

Backgrounds/Aims: The efficacy of neoadjuvant transarterial chemoembolization (N-TACE) in resectable hepatocellular carcinoma (HCC) remains open to debate. While N-TACE may reduce tumor size, its impact on long-term outcomes is inconclusive. Methods: This meta-analysis reviewed studies on N-TACE before surgical resection vs. liver resection (LR) single large hepatocellular carcinoma (SLHCC) up to March 2023 from four online databases. Results: Five studies with 1,556 patients were analyzed. No significant differences between N-TACE and LR groups were observed in 1-, 3-, or 5-year overall survival (OS) and disease-free survival (DFS). No significant differences were noted in intraoperative blood loss between groups. Subgroup analysis showed favorable 1-, 3-, and 5-year OS with combination chemotherapy N-TACE (combination group), and better 1-year OS in the LR group with single-agent chemotherapy N-TACE (single-agent group). Five-year DFS favored LR in the single-agent group, and N-TACE in the combination group. Conclusions: Managing SLHCC requires intricate considerations, and the treatment strategies for this challenging subgroup of HCC need to be improved. The influence of N-TACE on long-term survival depends on the specific chemotherapy regimen employed, and its impact on intraoperative blood loss in SLHCC appears limited.

• 유통과학연구
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• 제22권10호
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• pp.103-110
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• 2024

Purpose: This study investigated the microbial status of beverages and desserts containing strawberries sold at coffee outlets in Busan, South Korea. The study sought to identify differencesin types of foodservice management and microbial status of beverages and desserts. Research design and methodology: This study compared microbial status between franchised and single-unit outlets via microbial laboratory tests. In addition, impact of risk factors on microbial status were investigated. We analyzed the data using independent t-tests and chi-square tests. In order to measure the impact of risk factors on microbial status, multiple regression was run. We expected franchised outlets to be more likely to apply food safety practices than single-unit outlets. The principal results: Results of microbial testing showed that franchised outlets had a higher microbial status than single-unit outlets. The results showed that franchise outlets were more inclined to adhere to food safety practices than single-unit outlets when it comes to total number of bacteria however for coliform group results showed otherwise. Major conclusions: These study results suggest that a standard food safety and sanitation manual for coffee outlets is needed, especially for single-unit coffee outlets. The current inspection items should be revised accordingly to ensure customer safety.

• 노동경제논집
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• 제32권1호
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• pp.57-75
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• 2009

이 논문은 미국에서 1997년에 새롭게 제공된 "저소득층의 어린이와 임산부를 위한 의료지출 보조프로그램"이 미혼모 또는 편모 가정의 모친의 노동공급에 미치는 영향에 대하여 연구하였다. 1999년부터 2005년까지의 CPS(Current Population Survey)의 여성노동인구 자료를 사용하였다. Probit 모델과 Heckman Two-Step Model을 사용하여 통계분석을 해본 결과, 의료지출 보조프로그램과 평균 노동시간은 통계적으로 유의한 정(正)의 상관관계를 나타내었고, 노동시장 참여는 비유의적인 통계 결과를 발견하였다.

• Structural Engineering and Mechanics
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• 제32권5호
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• pp.685-699
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• 2009

Current research and development of high performance concrete, together with study of phenomena that are pertinent to impact resistance, have lead to a new generation of barriers with improved properties to resist impact loads. The paper reviews major properties and mechanisms that affect impact resistance of concrete barriers as per criteria that characterize the resistance. These criteria are the perforation limit, penetration depth and the amount of front and rear face damage. From the long-known, single strength parameter that used to represent the barriers' impact resistance, more of the concrete mix ingredients are now considered to be effective in determining it. It is shown that the size and hardness of the aggregates, use of steel fibers and micro-silica have different effects on performance under impact and on the resistance. Additional pertinent phenomena, such as the rate and size effects, confinement and local versus global response, are pointed out with their reference to possible future developments in the design of impact resisting concrete barriers.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.969-973
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• 2007

The heavy-weight floor impact sound field of the receiving room in a testing building with bearing wall structure was investigated using bang machine and impact ball. The sound field was investigated through the impact sound pressure level distribution by the field measurement and computational analysis. Predicted sound field using the computational analysis agree with measurement result in the low frequency band. Result shows that standard deviations of the single number rating value are about 2dB in each impact source. Particularly, impact sound pressure level at 120cm height in 63Hz octave band was 5dB lower than spatial averaging value. It was found that receiving positions in the ministry of construction and transportation notice should be reconsidered.

• 자동차안전학회지
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• 제10권3호
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• pp.13-19
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• 2018

This research is to optimize Single-Piece Side otr reinforcement using Hot-stamping and to strengthen weak regions on Single-Piece Side otr reinforcement. As a consequence, the weight and the number of parts were reduced and resulting in improvement of impact and stiffness performance when compared to multi-piece construction.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.631-635
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• 2006

In this study, simplified methods on measurement and evaluation of heavy-wight impact sound was proposed due to provide easy quality control method to construction engineers. The simplified methods include using of rubber impact ball instead of bang machine, reduced number of measuring and impact positions which is prescribed as over 4 points, using of hand-held sound level meter as a frequency analyser and prediction equation for $L_{i.Fmax.AW}$, single number rating, using $L_{Amax}$, and $L_{Lmax}$ at each frequency band. The results showed that a method of boundary driving and boundary measuring is the most similar to the current rating method.

• 한국축산시설환경학회지
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• 제12권3호
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• pp.151-160
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• 2006

For even distribution of liquid manure in the field, a boom nozzle type spreader was designed and studied to determined its suitability for small scale crop production farms. Boom nozzle type spreader was compared in the impact triple nozzle and impact single nozzle type spreader. Spreading uniformity of the boom nozzle type liquid manure spreader showed 5.2% (C.V.) and impact single nozzle type spreader showed 6.9% (C.V.). The spreading uniformity of the impact triple nozzle type spreader was quite uneven, therefore, the spreader could be modified as twin nozzle for spreading in orchard farm. The wheel axle height adjustable type liquid manure spreader has higher the stability and it considered much useful on the hilly agricultural land.

• 디지털융복합연구
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• 제19권9호
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• pp.349-360
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• 2021

본 연구의 목적은 청소년 한부모의 스트레스 상황이 학업지속에 미치는 영향에서 여가, 문화, 정보통신 영역에서의 한부모를 위한 사회적 지원이 조절효과를 나타내는 지 검증함에 목적이 있다. 이를 위해 18세 이상의 임신 중인자나 임신해 있으면서 출산 후 자녀를 양육할 계획을 가진 자, 자녀를 낳아 키우고 있는 청소년 한부모 248명을 대상으로 기술통계와 로지스틱 분석을 실시하였다. 그 결과 4명 중 1명이 수혜자로, 청소년 한부모들의 스트레스로 인한 학업 중단 경향을 여가, 문화, 정보통신비 지원이 조절하여 학업지속의 가능성을 증가시키고 있었다. 이러한 결과는 여가, 문화, 정보통신비 지원이 스트레스로 인해 학업을 중단하려는 청소년 한부모의 학업지속 가능성을 높이는 데 효과적으로 기여하고 있음을 보여준다. 따라서 청소년 한부모의 학업지속을 위해 여가와 문화, 정보통신 영역에서의 사회적 지원을 강화할 필요가 있다.