• Fire Science and Engineering
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• v.33 no.1
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• pp.23-29
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• 2019

Rechargeable battery such as lithium-ion battery has been noticed as a kinds of the energy storage system in the recent energy utilization and widely used actually in various small electronic equipment and electric vehicles. However, many thermal runaway caused battery accidents occurred recently, which still is obstacle for advanced application of lithium ion battery. One of the main differences to general fires is the existence of ionized electrolyte with electron during combustion. Therefore, we simply simulated the ion addition effects of battery fires by introducing an ionized fuel in jet diffusion flames. When the ionized methane through a corona discharge was used as fuel, the overall flame stability and shape such as flame length showed no significant difference from normal methane flame, but NOx and CO emissions measured at the post flame region decreased. The ion addition effect of methane oxidation was also numerically simulated with the modeling of hydrogen addition in the mixture. It was confirmed that the hydrogen addition at a fixed temperature had a similar effects on ionization of methane and hence could be modeled successfully.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6D
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• pp.819-829
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• 2008

Fatigue cracking occurs over long time period because dynamic strength of slab continuously decreases by vehicle loading repetitively applied to the concrete pavement. To more accurately predict the fatigue life of the concrete pavement, the stress due to environmental loading should be considered prior to calculating the stress due to the vehicle loading because the stress due to temperature and moisture distribution always exists within the slab. Accordingly, a new fatigue model considering the environmental loading was developed in this research by evaluating factors of existing fatigue models most widely used and by making data points from the models. The applicability of the new model was evaluated by performing a fatigue analysis on the general concrete pavement structure using local climatic and traffic conditions in Korea. It was concluded that the top-down cracking due to the tensile stress at top of the slab is dominant cause of the fatigue failure than the bottom-up cracking occurred at bottom of the slab. More advanced fatigue analysis considering vehicle speed is expected by developing this study.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10c
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• pp.246-251
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• 2006

마이크로어레이 실험은 수 천에서 수 만개의 유전자 발현 결과를 동시에 측정할 수 있어 질병의 발현 형질 분류 등에 유용하게 이용되고 있다. 그러나 마이크로어레이 실험은 동일한 플랫폼의 실험이라 할지라도 환경 등에 따라 그 실험 결과에 차이가 나는 등 오차를 항상 포함하고 있다. 또한 마이크로어레이 실험은 아직 고가의 실험으로 분류되어 다수의 샘플에 대한 반복 실험 결과를 얻기 어려운 상황이다. 따라서 이종의 플랫폼, 데이터 포맷, 정규화 기법 등이 서로 다른 데이터를 효율적으로 통합하여 유용한 정보를 추출하는 새로운 방식의 개발이 필요하다. 본 논문은 이와 같은 문제를 해결하기 위한 기초 단계 연구 결과이다. 마이크로어레이 실험 데이터로부터 통계적 방법을 이용하여 유의(informative) 유전자를 추출하고 유전자 온톨로지(Gene Ontology : GO)와의 연계를 통하여 유전자 정보의 기능적 분류 결과를 사용자에게 제공하는 유전자 기능 분석 시스템의 설계 및 구현 방안을 보인다. 본 시스템의 실험방법에서는 3-Fold Filtering 기법을 통하여 발현 차가 큰 유전자를 추출하고, t-검정 기법에 의하여 이들 유전자를 순위화 하였으며, 이 중 상위 100개의 유전자를 유의 유전자로 추출하였다. 다음, 이 들 유의 유전자의 t-검정 값을 GO의 유전자 기능을 나타내는 해당 텀 (term)에 가중치로 부과하여 각 유전자들과 기능적으로 연관성이 높은 텀들을 추출한다. 또한 본 연구의 유효성을 검증하기 위하여 본 시스템에 의한 마이크로어레이 데이터 분석 결과를 전문가에 의한 유전자 기능 분석 결과와 비교한다.투명성 있는 서비스를 제공하고 높은 신뢰성과 안정성이 확보될 수 있도록 구성하고자 한다. Query 수행을 여러 서버로 분산처리하게 함으로써 성능에 대한 신뢰성을 향상 시킬 수 있는 Load Balancing System을 제안한다.할 때 가장 효과적인 라우팅 프로토콜이라고 할 수 있다.iRNA 상의 의존관계를 분석할 수 있었다.수안보 등 지역에서 나타난다 이러한 이상대 주변에는 대개 온천이 발달되어 있었거나 새로 개발되어 있는 곳이다. 온천에 이용하고 있는 시추공의 자료는 배제하였으나 온천이응으로 직접적으로 영향을 받지 않은 시추공의 자료는 사용하였다 이러한 온천 주변 지역이라 하더라도 실제는 온천의 pumping 으로 인한 대류현상으로 주변 일대의 온도를 올려놓았기 때문에 비교적 높은 지열류량 값을 보인다. 한편 한반도 남동부 일대는 이번 추가된 자료에 의해 새로운 지열류량 분포 변화가 나타났다 강원 북부 오색온천지역 부근에서 높은 지열류량 분포를 보이며 또한 우리나라 대단층 중의 하나인 양산단층과 같은 방향으로 발달한 밀양단층, 모량단층, 동래단층 등 주변부로 NNE-SSW 방향의 지열류량 이상대가 발달한다. 이것으로 볼 때 지열류량은 지질구조와 무관하지 않음을 파악할 수 있다. 특히 이러한 단층대 주변은 지열수의 순환이 깊은 심도까지 가능하므로 이러한 대류현상으로 지표부근까지 높은 지온 전달이 되어 나타나는 것으로 판단된다.의 안정된 방사성표지효율을 보였다. $^{99m}Tc$-transferrin을 이용한 감염영상을 성공적으로 얻을 수 있었으며, $^{67}Ga$-citrate

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.1 s.49
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• pp.59-64
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• 2005

In case of lipsticks, observer's subjective sensitivity has been the main index to estimate gloss and gloss-lasting capability. The glossmeter has been applied to measure the gloss of make-up cosmetics like nail enamel, however is not effective for lipstick because of uneven sampling. Also gloss-lasting capability couldn't have been measured. In this study, we optimized measurement methods of gloss and gloss-lasting capability of lipsticks, which are highly correlated to subjective sensory tests. We set up the standard methods of gloss measurement by changing application conditions, for example, materials, sizes and application number of times and so on. And we introduced optimizing measurement system, in which shaking speed and temperature were controlled to measure gloss-lasting capability. Applying our methods, the gloss values were very close to the results of sensory tests, and we could express the gloss and gloss-lasting capability of lipsticks numerically Repeatability and reproducibility of our methods were certified by six-sigma statistical tool.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.1
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• pp.47-56
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• 2018

Providing high-quality meteorological observation data at sites that represent actual farming environments is essential for useful agrometeorological services. The Automated Agricultural Observing System (AAOS) of the Korean Meteorological Administration, however, has been deployed on lawns rather than actual farm land. In this study, we show the inaccuracies that arise in AAOS data by analyzing temporal and vertical variation and by comparing them with data recorded by the National Center for AgroMeteorology (NCAM) tower that is located at an actual farming site near the AAOS tower. The analyzed data were gathered in August and October (before and after harvest time, respectively). Observed air temperature and water vapor pressure were lower at AAOS than at NCAM tower before and after harvest time. Observed reflected shortwave radiation tended to be higher at AAOS than at NCAM tower. Soil variables showed bigger differences than meteorological observation variables. In August, observed soil temperature was lower at NCAM tower than at AAOS with smaller diurnal changes due to irrigation. The soil moisture observed at NCAM tower continuously maintained its saturation state, while the one at AAOS showed a decreasing trend, following an increase after rainfall. The trend changed in October. Observed soil temperature at NCAM showed similar daily means with higher diurnal changes than at AAOS. The soil moisture observed at NCAM was continuously higher, but both AAOS and NCAM showed similar trends. The above results indicate that the data gathered at the AAOS are inaccurate, and that ground surface cover and farming activities evoke considerable differences within the respective meteorological and soil environments. We propose to shift the equipment from lawn areas to actual farming sites such as rice paddies, farms and orchards, so that the gathered data are representative of the actual agrometeorological observations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.151-157
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• 2018

Among the various sensors for measuring traffic, PVDF (polyvinylidene fluoride) piezoelectric sensors are used to classify vehicles because they can detect the axle of the vehicle. Piezoelectric sensors are embedded in road pavements and are always exposed to traffic loads and environmental loads. Therefore, the life expectancy is very short, less than 6 years. Traffic control is essential for reinstallation and data collection is interrupted during the failure period. The lifespan will increase if the sensor installation depth is increased. In this study, the sensor signal output was analyzed with a variable depth of sensor installation to verify the possibility of deeper installation. Furthermore, various parameters, such as the weight and speed, were analyzed. The wheel load is applied using APT. As a result, the MSI BL sensor output signal is higher than 100mV when installed at 3cm, which is reliable. If the location of the sensor is deeper in the pavement, the expected lifetime of the sensor is also increased. On the other hand, the MSI cable was found to be less than 100mV at the shallowest depth of 1cm, making it impossible for field applications.

• Food Engineering Progress
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• v.23 no.2
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• pp.125-133
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• 2019

The characteristics of extracts and precipitates after extraction at different water temperature (25, 50, 75, 95℃), ethanol ratio (25, 50, 75, 100%), and extraction method (stir, soak, autoclave) of yam powder and raw yam were investigated. The total polyphenol content was the highest in the 50% ethanol extract of yam powder. The DPPH radical scavenging activity was the highest in the 75% ethanol extraction and the crude saponin content was the highest in the 95℃ water extraction. Tyrosinase inhibitory activity was the highest in 95℃ water extraction, low concentration of ethanol extraction, and autoclave extraction. The peak viscosity, trough, and final viscosity of the precipitates increased after ethanol extraction, whereas decreased after the 95℃ water extraction and the autoclave, indicating the destruction of starch granules. This was confirmed by observing the starch granules broken using the SEM. The significance of this study was to investigate the possibility of the use of yam resources as a material, processing product development, skin beauty functional food and cosmetic material.

• Journal of Conservation Science
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• v.35 no.2
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• pp.99-115
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• 2019

The Royal Tombs at Songsanri is one of the most important historic site for ancient historical study in Korean Peninsula. Since the excavation of the tombs, continuous exposure to the outside environment and the negative effects of the artificial air conditioning system have caused significant threats to the thermal environment stability of the tombs. Unlike the outside temperature that shows significant differences according to seasonal changes, the burial chamber of the tombs had a relatively stable temperature range of 11.4 to $22.2^{\circ}C$ throughout the year, and the standard deviation of temperature was within 3.5. It was revealed that major factors affecting the microclimate of the tombs were inflow of outdoor air, wind direction and speed, and all of them had closely related to airtightness of the tombs. The solar radiation was in inverse proportion to the thickness of burial mounds, and thus Royal Tomb of King Muryeong, which has the thickest burial mound, was least affected by solar radiation. Especially, microclimate of the tombs caused to the highest influence with artificial environmental changes due to access by people, which varied in proportion to the number of accessed people and time of stay. Currently, the inside of the tombs are sealed and always in saturated condition, it is very vulnerable to dew condensation. As a result of analyzing the possibility of condensation in each tomb, all the tomb No. 5, tomb No. 6 and Royal Tomb of King Muryeong had condensation most of the time throughout the year. It is required to make a proper conservation environment for the Royal Tombs at Songsanri.

• Journal of Bio-Environment Control
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• v.11 no.1
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• pp.5-11
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• 2002

In this study, new development of natural ventilation window was accomplished to control environment of greenhouse with no use of farced ventilation during hot season. The ventilation effect of developed ventilation window was investigated in experimental greenhouse which was designed using side wall panel and folding type panel fur natural ventilation. Folding panel type ventilation window was designed to open upper part of the side wall and top of the roof using two hinges which are located bottom of the side wall and the roof panel to grab one side of each panels and guide the other side along with the guidance rail. Developed ventilation window has top ventilation part with maximum moving distance X=ι (1-cos$\theta$)=848.5 mm and side ventilation part with maximum moving distance Y=ι/2 $\times$sin$\theta$=1,184.4 mm at 45$^{\circ}$ of theoretical opening angle. It took 4.5 minutes to open roof vent fully and temperature at 1.2 and 0.8 m height decreased after 1 minute from starting opening and became equilibrium state maintaining 3-4$^{\circ}C$ difference after 2 minutes from complete opening. Air exchange rate was 15.2~39.3 h$^{-1}$ which was more than 10~15 h$^{-1}$ of continuous type and Venlo type greenhouse. The descent effect of temperature by ventilation windows was two times higher than Venlo type greenhouse.

• Fire Science and Engineering
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• v.29 no.6
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• pp.57-64
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• 2015

Carbon dioxide extinguishing systems are broadly used for onshore and offshore fire accidents because of excellent performance and low cost. However, there is risk with carbon dioxide systems, which have caused many injuries and deaths by suffocation associated with industrial and marine fire protection applications. In this study, a numerical analysis was performed to predict the fire suppression characteristics of a carbon dioxide system in the compressor room of ships. A double protection safety system is suggested to prevent suffocation accidents from carbon dioxide extinguishing systems. Four scenarios were selected to study the variation of the heat release rate, maximum temperature, a $CO_2$ and $O_2$ mole fraction, and fire suppression characteristics with the carbon dioxide system. The importance of proper design is suggested for a ventilation system in the compressor room of ships.