• 한국화재소방학회논문지
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• 제23권5호
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• pp.90-95
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• 2009

산불의 확산에 있어 바람은 매우 중요한 인자이다. 바람은 또한 지형에 따라 변화되며 이로 인해 다른 확산형태를 가지게 된다. 따라서 산불의 확산속도 해석을 위해 먼저 풍속에 따른 화염각 변화를 살펴볼 수 있다. 이는 바람에 의해 변화된 화염각으로 인해 미연소 지표 대상물에 열전달의 차이를 가져오기 때문이다. 풍속이 증가할수록 화염과 지표면이 가까워짐으로 인해 열전달이 증가되어 미연소물질이 착화온도에 빨리 도달하게 되어 화염의 확산속도가 빨라지게 된다. 따라서 본 연구에서는 바람에 의한 화염각 변화 산정식을 Froude number 관계식을 이용한 수치해석과 실험을 통해 제시하였다. 그 결과, Froude number 계수 A=1.85를 제시하였고 제시된 식에 대한 실험 화염각의 평균 오차각은 약 $3.3^{\circ}$로 다른 모델식에 비해 실험값과 유사한 결과를 나타내었다. 향후, 이 연구를 통해 열전달 수치해석을 통한 화염확산연구에 활용될 수 있을 것으로 사료된다.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.443-449
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• 2022

With climate change and the global population growth, the frequency and scope of wildfires are constantly increasing, which threatened people's lives and property. For example, according to California Department of Forestry and Fire Protection, in 2020, a total of 9,917 incidents related to wildfires were reported in California, with an estimated burned area of 4,257,863 acres, resulting in 33 fatalities and 10,488 structures damaged or destroyed. At the same time, the ongoing development of technology provides new tools to simulate and analyze the spread of wildfires. How to use new technology to reduce the losses caused by wildfire is an important research topic. A potentially feasible strategy is to simulate and analyze the spread of wildfires through computing technology to explore the impact of different factors (such as weather, terrain, etc.) on the spread of wildfires, figure out how to take preemptive/responsive measures to minimize potential losses caused by wildfires, and as a result achieve better management support of wildfires. In preparation for pursuing these goals, the authors used a powerful computing framework, Spark, developed by the Commonwealth Scientific and Industrial Research Organization (CSIRO), to study the effects of different weather factors (wind speed, wind direction, air temperature, and relative humidity) on the spread of wildfires. The test results showed that wind is a key factor in determining the spread of wildfires. A stable weather condition (stable wind and air conditions) is beneficial to limit the spread of wildfires. Joint consideration of weather factors and environmental obstacles can help limit the threat of wildfires.

• 디지털융복합연구
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• 제4권1호
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• pp.9-16
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• 2006

Function Point(FP) is well spread and advanced methodology in software costing. But FP is not common in game contents costing. It is one reason that Game Contents is a new area in software costing. And, ISO/IEC FDIS 19761(final draft) recommends not to use FP method in game contents costing. So we suggested new methodology in that area which is called Game Factor Point Method(GFPM). In this paper, we studied more about the weight of the game factor. We hope this will clarify them. We made definition of game factor, and studied more detail about Mission which was a little ambiguous in prior study. We also studied difficulties of game factor which will be a very important factor in game contents costing.

• 한국정보통신학회논문지
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• 제6권4호
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• pp.616-623
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• 2002

삼각형 마이크로스트립 패치를 기본으로 프랙털 확장시킨 삼각형 프랙털 안테나(Triangular Fractal Antenna)를 제안한다. TFA의 기본모드와 고차모드에 대한 공진주파수를 스케일링 인자 (scaling factor)를 변화시켜 조절한다. 스케일링 인자의 변화에 따라 공진주파수가 확산 혹은 집중되는 현상을 보인다. 각 프랙털 패치(fractal patch)에서 공진되는 주파수들은 대수 주기적으로 나타난다 이 논문에서 제안된 삼각형 프랙털 안테나는 다중대역 특성을 갖는 시스템에 적용 가능하다.

• 농업과학연구
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• 제6권2호
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• pp.192-197
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• 1979

분무철포립자(噴霧撤布粒子)의 연구(硏究)에 있어서 공기중(空氣中)에 표류하고 있는 분무립자(噴霧粒子)의 직경(直徑)을 직접(直接) 측정(測定)하기 어려우므로 입자(粒子)자국의 직경(直徑)과의 비(比)인 확산비(擴散比)(Spread factor)를 이용(利用)함이 일반적(一般的)이다. 물에 Geigy Red Herbicide 물감을 0.5%로부터 2%까지의 중량비(重量比)로 혼합하여 분무액(噴霧液)을 준비하고 균일(均一)한 크기의 입자발생장치(粒子發生裝置)로 발생(發生)한 공기중(空氣中)의 표류 입자(粒子)의 직경(直徑)을 측정(測定)하고 이들 입자(粒子)들을 바로 표본기지(標本期紙) 또는 Eucalypt 잎위에 받아서 입자(粒子)자국의 직경(直徑)들을 측정(測定)하여 입자(粒子)자국의 직경(直徑) 대(對) 공기중(空氣中)의 표류입자(粒子)의 직경(直徑)의 비(比)인 확산비(擴散比)를 구(求)한 결과(結果) 다음과 같은 결론(結論)을 얻었다. 공기중(空氣中)의 표류입자(粒子)의 직경(直徑)과 Kromekote 용지(用紙) 또는 Eucalypt 잎위에 살포(撒布)된 입자(粒子)자국직경(直徑)의 상관성(相關性)의 방정식(方程式)의 일반형(一般形)은 지수방정식(指數方程式)인 $Y=aX^b$로서 log-log 그라프용지(用紙) 상(上)에 직선관계식(直線關係式)으로 나타났다. 엷은 농도 용액의 확산비가 진한 농도 용액의 확산비 보다 일반적(一般的)으로 크게 나타났다. Eucalypt 잎 상(上)에서의 확산비는 용액이 잎속으로 침투하고 엽면(葉面)의 오목한 기공(氣孔)을 가진 표면(表面)으로 인(因)하여 Kromekote 용지(用紙) 상(上)의 확산비보다 상당히 작게 나타났다. Eucalypt 잎 상(上)에 낙하된 입자(粒子)의 평균(平均)두께 추정식(推定式)은 $Y=aX^b$로서 확산비의 상관식(相關式)과 같은 형(形)이었고 이 식(式)은 병충해방제(病蟲害防除) 최소직경(最小直徑)의 입자(粒子)를 기준(基準)할 때 이기준치(基準値)보다 큰 입자(粒子)를 살포(撒布)하는 경우에 있어서 입자(粒子)가 클수록 과잉살포결과를 초래하고 있음을 의미(意味)하고 있다.

• 한국농공학회논문집
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• 제54권3호
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• pp.37-45
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• 2012

Recently, the livestock industry in Korea was heavily affected by the outbreak of official livestock diseases such as foot and mouse disease, high pathogenic avian influenza, swine influenza, and so on. It has been established that these diseases are being spread through direct contact, droplet and airborne transmission. Among these transmissions, airborne transmission is very complex in conducting field investigation due to the invisibility of the pathogens and unstable weather conditions. In this study, the airborne transmission was thoroughly investigated inside a pig house by conducting tracer gas ($CO_2$) experiment because experiment with real pathogen is limited and dangerous. This is possible as it can be assumed that the flow is similar pattern very fine particles and gas. In the experiment, the ventilation structure as well as the location of gas emission were varied. The $CO_2$ detection sensors were installed at 0.5 and 1.3 m height from the floor surface. The tracer gas level was measured every second. Results revealed that the direction of spread can be determined by the response time. Response time refers to the time to reach 150 ppm from the gas emission source at each measuring points. The location of the main flow as well as the gas emission was also found to be very important factor causing the spread.

• Journal of Korean Neurosurgical Society
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• 제52권4호
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• pp.372-376
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• 2012

Objective : The purpose of this large prospective study is to assess the association between the disappearance of the lateral spread response (LSR) before and after microvascular decompression (MVD) and clinical long term results over two years following hemifacial spasm (HFS) treatment. Methods : Continuous intra-operative monitoring during MVD was performed in 244 consecutive patients with HFS. Patients with persistent LSR after decompression (n=22, 9.0%), without LSR from the start of the surgery (n=4, 1.7%), and with re-operation (n=15, 6.1%) and follow-up loss (n=4, 1.7%) were excluded. For the statistical analysis, patients were categorized into two groups according to the disappearance of their LSR before or after MVD. Results : Intra-operatively, the LSR was checked during facial electromyogram monitoring in 199 (81.5%) of the 244 patients. The mean follow-up duration was $40.9{\pm}6.9$ months (range 25-51 months) in all the patients. Among them, the LSR disappeared after the decompression (Group A) in 128 (64.3%) patients; but in the remaining 71 (35.6%) patients, the LSR disappeared before the decompression (Group B). In the post-operative follow-up visits over more than one year, there were significant differences between the clinical outcomes of the two groups (p<0.05). Conclusion : It was observed that the long-term clinical outcomes of the intra-operative LSR disappearance before and after MVD were correlated. Thus, this factor may be considered a prognostic factor of HFS after MVD.

• 동아시아식생활학회지
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• 제24권2호
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• pp.234-241
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• 2014

In this study, we assessed the antioxidant activities and quality characteristics of cookies containing various concentrations (0, 1, 3 and 5%) of Eleutherococcus sessiliflorus leaf powder. Antioxidant activity was estimated based on DPPH free radical scavenging activity and total content of phenolic compounds in Eleutherococcus sessiliflorus leaf powder and cookies. The quality characteristics of Eleutherococcus sessiliflorus leaf cookies were estimated based on spread factor, loss rate, leavening rate, color, texture and sensory evaluation, polyphenol contents, DPPH free radical scavenging activity, as well as spread factor of cookies significantly increased. L value, b value and hardness of cookies decreased with increasing Eleutherococcus sessiliflorus leaf powder content. Finally, the sensory evaluation showed the highest scores for cookies containing 3% Eleutherococcus sessiliflorus leaf powder. From these results, we suggest that Eleutherococcus sessiliflorus leaf is a good ingredient for increasing consumer acceptability as well as the functionality of cookies.

• 한국화재소방학회논문지
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• 제22권2호
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• pp.57-62
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• 2008

한국의 실내장식재로는 대부분 벽지를 사용하고 있다. 이러한 주거공간에 화재발생시 화재 확대요인중의 하나는 벽지의 연소를 통해 이루어진다. 그동안 산소지수 관련연구들이 많이 이루어져 왔지만 상온에서의 연구가 많았다. 본 연구에서는 실내화재에서 화재의 확대요인이 될 수 있는 벽지의 산소지수가 상온과 고온에서 얼마나 차이가 발생하며 이러한 차이가 화재확대에 미치는 영향을 고찰하고자 하였다. 실험을 통해 LOI 및 TOI 측정한 결과 벽지의 상온과 고온에서의 산소지수는 $5{\sim}8%$정도의 차이가 나타났다. 실험에서 산소지수 0.1%의 차이로도 연소 길이에 현저한 차이가 나타나기 때문에 고온에서의 산소지수 감소가 화재확대에 큰 영향을 미치는 요인임을 알 수 있었다.

• 한국식품조리과학회지
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• 제25권1호
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• pp.98-105
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• 2009

This study examined the effects of adding four different amounts (0%: control, 4%: M-4, 8%: M-8, 12%: M-12) of button mushroom (Agaricus bisporous) powder on the quality characteristics of cookies. The bulk density and pH of the dough, and firmness, color, spread factor, consumer acceptability of cookies, and total phenol compound content and free radical scavenging activity of mushroom powder and cookies were measured. While the bulk density and pH of the dough as well as spread factor of the cookies significantly decreased, the firmness, L values and total phenol compound contents and free radical scavenging activity of the cookies significantly increased with increasing mushroom powder content(p<.05). The consumer acceptability scores for the button mushroom cookie groups ranked significantly(p<.05) higher than those of the control group in general acceptability, appearance, flavor, color, taste, and texture. This study suggests that button mushroom powder is a good ingredient for increasing the acceptability and functionality of cookies.