• 한국도로학회지:도로
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• v.13 no.3
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• pp.32-36
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• 2011

• KIISE Transactions on Computing Practices
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• v.21 no.3
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• pp.247-256
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• 2015

Since the Gulf War, air power has played a key role. However, the effect of high-tech weapons, such as laser-guided bombs and electronic optical equipment, drops significantly if they do not match the weather conditions. So, aircraft that are assigned to carry laser-guided bombs must replace these munitions during bad weather conditions. But, there are no objective criteria for when weapons should be replaced. Therefore, in this paper, we propose an algorithm to predict the hit rate of laser-guided bombs using cloud image processing. In order to verify the accuracy of the algorithm, we applied the weather conditions that may affect laser-guided bombs to simulated flight equipment and executed simulated weapon release, then collected and analyzed data. Cloud images appropriate to the weather conditions were developed, and applied to the algorithm. We confirmed that the algorithm can accurately predict the hit rate of laser-guided bombs in most weather conditions.

• Journal of Korean Society of Transportation
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• v.26 no.3
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• pp.119-128
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• 2008

Weather like rain, strong wind or snowfall may make the road condition deteriorated and sometimes induce traffic accidents, which lead to severe traffic congestion, thereby travelers may change their destinations elsewhere. Although origin-destination trip information is required to analyze transportation planning in urban area, there are little researches on the relationship between weather condition and travel patterns. This paper investigates the characteristics of travel patterns on expressway in rainy days of 2006. We compare the normal travel patterns with those of rainy days by the travel distance for each vehicle type. Results show that traffic volume and travel distance have been reduced in rainy days as we expect, and also show different travel patterns for weekday and weekend.

• Journal of Korean Society of Transportation
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• v.34 no.5
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• pp.394-408
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• 2016

This study aims to study the impact of weather conditions and locational characteristics of bike stations on the usage of public bike sharing system for efficient deployment and operation of public bike systems. Linear regression analysis is used to estimate the usage of public bikes of Goyang city. The statistical analysis shows that the usage rate increases with average temperature and decreases under high wind (over 7m/s) or high temperature (over $29^{\circ}$) condition. The usage rate of public bike sharing system can be differentiated by locational characteristics of bike station such as residential area, commercial area, park, school, and metro station. The usage rate increases in park and commercial areas from 10 AM to 3 PM, while it increases in school areas from 3 PM to 5 PM. Public bikes are highly used near the metro station from 5 PM to 8 PM. The stations in parks are highly used in late night, and the usage rate in CBD area increases after the midnight.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.304-304
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• 2011

열필라멘트 화학 기상 증착 공정(HWCVD, hot wire chemical deposition)은 낮은 기판 온도에서 다결정 실리콘 박막을 빠른 속도로 증착할 수 있는 방법이다. 이는 후처리가 없어도 전기적 특성이 우수한 박막을 저온에서 얻을 수 있기 때문에 녹는점이 낮은 기판에 증착을 할 수 있으며 공정비용 절감 효과가 있다. 이러한 박막 증착 공정 중 기상 핵생성에 의해 나노 입자가 생성되며, 새로운 관점에서는 그 농도와 크기가 박막 성장에 중요한 변수로 작용한다. 따라서 공정조건의 변화에 따라 생성되는 나노 입자의 크기 분포를 실시간으로 분석하여 박막 형성의 최적 조건을 찾는 연구가 필요하다. 하지만 이러한 입자 발생 특성에 관한 연구는 기존에 밝혀진 반응 메커니즘으로 인해 수치해석적 연구는 체계적으로 진행되었으나 실험적 연구의 경우 적합한 측정장비의 부재로 인해 제한이 있었다. 따라서 본 연구에서는 저압에서 실시간으로 나노입자 분포를 측정할 수 있는 PBMS (particle beam mass spectrometer)를 이용하여 열필라멘트 화학 기상 증착 공정 중 발생하는 입자의 존재를 확인하고 특성을 분석하였다. 실리콘 나노 입자의 측정은 PBMS 장비의 전단 부분을 HWCVD 배기 라인에 연결하여 진행하였으며 반응기 내 샘플링 위치, 필라멘트 온도, 챔버 압력, 작동기체의 비율을 변수로 하여 진행하였다. 그 결과 실리콘 나노 입자는 양 또는 음의 극성을 가진 하전된 상태임을 확인 하였고, 측정 조건에 따라 일부 단일 극성으로 존재하였다. 한편, 필라멘트 온도가 증가할수록 하전된 나노입자의 최빈값은 감소하였다. 또한 반응 가스인 SiH4 농도가 증가할수록 최빈값은 농도에 비례하여 증가하였다. 이런 결과는 기존 HWCVD 실험에서 투과 전자 현미경(TEM)을 이용하여 분석한 실리콘 나노 입자의 크기 분포 결과와 경향이 일치함을 확인하였다. 본 연구를 통하여 확인된 하전된 나노 입자의 존재를 실험적으로 확인하였으며 추후 지속적 연구에 의해 이러한 하전된 나노 입자가 박막 형성에 기여 하는 것을 규명하고 박막 형성 조건을 최적화하는데 중요한 역할을 할 것을 기대할 수 있다.

• Science of Emotion and Sensibility
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• v.26 no.4
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• pp.29-40
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• 2023

Anxiety is known to upset the balance of the attentional system and prioritize the stimulus-driven system over the goal-directed system; however, self-instruction induces goal-directed behavior with the self-regulation effect. This study verified the effects of meteorological and self-instruction conditions on pilot anxiety and flight task performance for in-service pilots in a virtual reality environment. The meteorological conditions were divided into visual meteorological and very low visibility conditions, and the flight tasks were conducted by varying whether or not self-instruction was performed. The experiment results reveal that anxiety and heart rate were higher, and the performance of the flight task was lower in the very low visibility condition. However, anxiety and heart rate were lower, and the performance of the flight task was higher in the self-instruction condition. This result suggests that accidents due to difficulty in flight may increase because of anxiety, but such accidents may decrease because of flight performance improvement by self-instruction.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.3
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• pp.162-169
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• 2016

The agrometeorological reference index means 'the agrometeorological damage possibility' or the possibility of the normal year climate condition to damage the crop cultivation in a certain region. It is a reference used to compare the cultivation risk of a crop by region. The global climate warming is expected to increase the winter temperature. At the same time, the frequency of extreme weather events will also increase. Therefore, people pay attention to the potential of low temperature-induced damages (e.g., frost damage and injury) to fruit trees under the future climate condition. However, simple damage projection based on climate conditions does not help the climate change adaptation in the practical aspect because the climate change affects the phenology of fruit trees as well. This study predicted the phenology of the pear, peach, and apple trees by using the climate change scenarios of major regions. Furthermore, low temperature induced agrometeorological reference indices were calculated based on the effects of temperature on each plant growth stage to predict the damage possibility. It was predicted that the breaking rest would delay more in the future while the bud-burst date and flowering date will be earlier. In Daegu, Jeonju, and Mokpo, the breaking rest delayed more as time passed. The bud-burst date and flowering date of Seoul and Incheon regions were later than other regions. Seoul and Incheon showed a similar pattern, while Daegu and Jeonju revealed a similar pattern. Busan and Mokpo also showed a similar pattern. All regions were safe from the frost damage during the dormancy period. However, plants were vulnerable to frost damage between the breaking rest and the bud-burst period. Regions showed different frost damage patterns between the bud-burst period and the flowering period. During the bud-burst and flowering period, the risk level decreased in general, although the risk of some areas tended to increase.

• Journal of Energy Engineering
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• v.4 no.3
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• pp.394-401
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• 1995

본 연구는 중심부에 액체, 외주부에 산화제가 흐르는 기액 동축분류의 유동장에 대한 것이다. 기액 동축 분사기는 연료의 분사량이 적은 소형 연소시스템을 고려하여, 실험은 연공비(W1/Wa)가 0.6 이하를 대상으로, 물과 공기를 사용하여 분사조건에 따른 분무특성과 기액 2상 분무류의 기본구조를 조사하여 액적의 확산, 기액혼합특성에 대하여 검토하여 다음과 같은 결론을 얻었다. 반경방향 기상속도분포 및 액적유속분포는 분구직경 및 분사조건에 관계없이 정규분포에 가까운 형태를 취하고 있으며, 각각 식 (2) 및 (3)으로 나타낼 수 있다. 기상속도는 반치폭은 축방향에 따라 일정한 구배 (≒4.6)로서 증가하며, 기상만의 단상분류의 구배(≒6)에 비해서 완만하다. 액적유속 반치폭은 축방향에 따라 더욱 완만한 구배(≒3.1)로서 증가한다. 무차원 액적유속분포는 축방향에 따라 일정한 구배(n≒1.5)로서 감소한다. 액적의 확산은 상대적으로 기액유량비가 클수록 효과적으라고는 말할 수 없고, 최대 확산을 이루는 최적의 기액유량비가 존재한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.10a
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• pp.247-252
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• 2000

In this paper, we discuss frequency allocation and sharing for high speed radio access network in domestic 5㎓ the band. In order to evaluate the possibility of frequency sharing between meterological radar and high speed radio access network we analyses radio interference of meterological radar by means of minimum coupling loss method and Monte Carlo simulation And simulations show that it is necessary to use DFS(Dynamic Frequency Selection) scheme for frequency sharing between meterological radar and high speed radio access network.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.4
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• pp.751-758
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• 2000

In this paper, we discuss frequency allocation and sharing for high speed radio access network in domestic 5GHz the band. In order to evaluate the possibility of frequency sharing between meteorological radar and high speed radio access network, we analyses radio interference of meteorological radar by means of minimum coupling loss method and Monte Carlo simulation. And simulations show that it is necessary to use DFS(Dynamic Frequency Selection) scheme for frequency sharing between meteorological radar and high speed radio access network.