• 제목/요약/키워드: wind intensity

검색결과 443건 처리시간 0.022초

산불 공중진화 방화선 구축형태 및 진화방법에 관한 연구 (Study of Aerial Fire Line Construction and Suppression Method on Forest Fire)

  • 배택훈;이시영
    • 한국화재소방학회논문지
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    • 제24권5호
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    • pp.26-31
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    • 2010
  • 본 연구는 우리나라의 각종 소.중형 및 대형 산불의 공중진화 경험을 바탕으로 산불행태와 헬기의 현장운영을 고려한 산불 공중진화 방화선 구축형태 및 진화방법에 대하여 제안하였다. 산불확산은 현장의 지세, 경사, 바람, 수종 등에 영향을 받으므로 공중진화 방화선을 구축할 때에는 연소방향 및 형태, 강도 등을 분석한 후 진화작업을 실시하여야 하며, 특히 연기로 인하여 시계가 방해 받으므로 안전을 고려해 진화작업을 하는 것이 중요하다. 따라서 본 연구에서는 산불현장 공중진화 경험을 바탕으로 A형에서 M형까지 13개의 산불 공중진화 방화선 구축형태 및 진화방법을 제안하였다.

A Study on a Vision Sensor System for Tracking the I-Butt Weld Joints

  • Kim Jae-Woong;Bae Hee-Soo
    • Journal of Mechanical Science and Technology
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    • 제19권10호
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    • pp.1856-1863
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    • 2005
  • In this study, a visual sensor system for weld seam tracking the I-butt weld joints in GMA welding was constructed. The sensor system consists of a CCD camera, a diode laser with a cylindrical lens and a band-pass-filter to overcome the degrading of image due to spatters and arc light. In order to obtain the enhanced image, quantitative relationship between laser intensity and iris opening was investigated. Throughout the repeated experiments, the shutter speed was set at 1/1000 second for minimizing the effect of spatters on the image, and therefore the image without the spatter traces could be obtained. Region of interest was defined from the entire image and gray level of the searched laser stripe was compared to that of weld line. The differences between these gray levels lead to spot the position of weld joint using central difference method. The results showed that, as long as weld line is within $\pm15^{o}$ from the longitudinal straight line, the system constructed in this study could track the weld line successfully. Since the processing time is no longer than 0.05 sec, it is expected that the developed method could be adopted to high speed welding such as laser welding.

동해의 열적작용이 해수순환에 미칠 수 있는 영향에 관한 고찰 (On the Possible Role of Local Thermal Forcing on the Japan Sea Circulation)

  • 승영호;김구
    • 한국해양학회지
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    • 제24권1호
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    • pp.29-38
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    • 1989
  • 동해 해수순환의 특징은 대한해협으로부터 유입된 난수가 동한난류를 형성하여 한국연안을 따라 북상한 후 다시 외해로 분리되어 나간다는 것과 북쪽에서부터 연안을 따라 남하하는 북한한류가 형성하는 반시계 방향의 순환류가 동해 북부에 존재한다는 사실일 것이다. 본 논문에서는 이러한 사실을 설명하기 위하여 간단한 역학적 모델을 수립하였다. 동해 해수순환을 기본적으로 유입-유출 형태라 한 후 여기에 해양-대기 열 교환을 적용하였으며 해수혼합에 의한 열의 소멸, 마찰에 의한 운동량의 소멸도 고려하였다. 결과에 의하면, 상기의 순환특징은 열역학적 요인에 의하여 기인됨이 밝혀졌다. 또한, 열교환의 정도에 따라 여러가지 순환형태가 나타날 수 있음도 보였다.

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춘천지역 도시열섬의 특성과 대기질에 미치는 영향 (Aspects of Urban Heat Island and Its's Effect on Air Pollution Concentration in Chunchon Area)

  • 이종범;김용국;김태우
    • 한국대기환경학회지
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    • 제9권4호
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    • pp.303-309
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    • 1993
  • An observational study of urban heat island was carried out using field data obatined during 6 days in May and August 1992 in Chunchon(population size 180.000). Air temperature was measured at 64 points along two sampling ruoutes by themisters attached to cars. Both routes cover urban and rural area and across the cneter of urban area. Continuous observation of air sonde was perfomed to clarify heights of nocturnal boundary layer(NBL) at the center of urban area. Surface meteorological observations were performed at both urban and rural sites. This study showed that heat island phenomena was obviously observed at the urbanized area during the night time with low wind speed. The average NBL heights exteded to about 10 meters, but varied with meteorological conditions. After sunset, the air temperature decreased with time at both sites and cooling rate at the urban site was greater than the rural site. The maximum heat island intensity was 7.5$^{\circ}$C at 21 LST, May 4. Usingthe two meteorological data sets obtained from urban and rural sites, the air pollutant concentration was calculated by Gaussian plume model which can obtain not only horizontal distribution of concentration but also vertical distribution. The result indicated that the concentration resulted from urban meteorological data set was lower than that from rural meteorological data set. It was also calculated that the air pollutant extended to higher level in urban meteorological data set than that in rural meteorological data set.

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수위변동에 따른 갯벌의 물리적 환경특성의 변화 (Variation of Physical Characteristic of Tidal Flat's Environment by Water Level Change)

  • 박종화
    • 한국환경복원기술학회지
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    • 제2권3호
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    • pp.1-9
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    • 1999
  • This paper described the results of the characteristics of the near-bottom flow and field analysis of the tidal flats sediment. It was the aim of this paper to grasp current flow of tidal flat's environment and influence factor for environmental change forecast of tidal flats. Field measurement of water velocity, water elevation, bed materials test, and temperature distribution of tidal flat were conducted. Thereafter, current flow, turbidity and temperature distribution of tidal flat sediment have been discussed. The field research results showed that the fluctuating velocity near the seabed before and after its appearance at low tide was strongly affected by the wind wave. The resuspension of the sea-bottom sediment took place with great intensity before and after the appearance of the seabed at low tide. Both the sea water level and the weather condition were a significant influential factors. Such as, temperature and turbidity just on the surface and the shallow layer of seabed sediments were varied largely with time and weather conditions, but that its deeper layers was almost constant. Temperature on the seabed sediments was strongly influenced by irradiance and water depth. The temperature variation of the tidal flat and the variation characteristics of the current flow and turbidity depend greatly on the inhabiting environment of the tidal flat benthic organism.

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The Structural Design of Tianjin Goldin Finance 117 Tower

  • Liu, Peng;Ho, Goman;Lee, Alexis;Yin, Chao;Lee, Kevin;Liu, Guang-lei;Huang, Xiao-yun
    • 국제초고층학회논문집
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    • 제1권4호
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    • pp.271-281
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    • 2012
  • Tianjin Goldin Finance 117 tower has an architectural height of 597 m, total of 117 stories, and the coronation of having the highest structural roof of all the buildings under construction in China. Structural height-width ratio is approximately 9.5, exceeding the existing regulation code significantly. In order to satisfy earthquake and wind-resisting requirements, a structure consisting of a perimeter frame composed of mega composite columns, mega braces and transfer trusses and reinforced concrete core containing composite steel plate wall is adopted. Complemented by some of the new requirements from the latest Chinese building seismic design codes, design of the super high-rise building in high-intensity seismic area exhibits a number of new features and solutions to professional requirements in response spectrum selection, overall stiffness control, material and component type selection, seismic performance based design, mega-column design, anti-collapse and stability analysis as well as elastic-plastic time-history analysis. Furthermore, under the prerequisite of economic viability and a series of technical requirements prescribed by the expert review panel for high-rise buildings exceeding code limits, the design manages to overcome various structural challenges and realizes the intentions of the architect and the client.

${\ll}$외대비요(外臺秘要)${\gg}$의 중풍(中風)에 관(關)한 고찰(考察) (The Considerations of Stroke in Oidaibiyo(外臺秘要))

  • 조규선;권정남;신길조;이원철
    • 대한한방내과학회지
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    • 제18권2호
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    • pp.112-130
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    • 1997
  • This study has been carried out to investigate the cause, pathological mechanism and treatment of stroke in Oidaibiyo(外臺秘要), written by Wangdo(王燾). The results were follows : 1. Oidaibiyo(外臺秘要), which is written by Wangdo gives an account of the symptomatic degree of intensity and diachronic procedure in the chapter of stroke. 2. The cause of stroke is quoted mainly from External Wind(外來風邪), and the hyper-sexual intercourse, hyperalimentation, hyper -consciousness, excessive lavour and so forth as additional. And personal character and external effect, like the climate conditions are also much affected the outbreak of stroke. 3 With respect to the diagnosis of stroke, pulse means here quoted from its conception in Chungumyobang(千金要方) Jebungwonhuron(諸病源候論), and pulse plays an important role in diagnosis of stroke. 4. The treatment for stroke generally attaches much importance to medicine therapy. The concrete cure, BalhanGeopungbub(發汗祛風法) has been mainly available, and the usage of Cheongyulyak(淸熱樂) has been increased, contray to formal.

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A Study on the Change of Heavy Snow Strength by SST in Influence of Continental Polar Air Mass

  • Park, Geon-Young;Ryu, Chan-Su
    • 통합자연과학논문집
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    • 제7권1호
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    • pp.39-44
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    • 2014
  • The results of the synoptic meteorological analysis showed that when the cold and dry continental high pressure was extended, heavy snow occurred at dawn when the upper atmosphere cooled. In particular, when the continental high pressure was extended and the upper pressure trough passed through, heavy snow occurred due to the convergence region formed in the west coast area, sometimes in the inland of the Honam area. In addition, it was verified that the changes in the humidity coefficients in the upper and lower layers are important data for the determination of the probability, start/end and intensity of heavy snow. However, when the area was influenced by the middle-latitude low pressure, the heavy snow was influenced by the wind in the lower layer (925 hPa and 850 hPa), the equivalent potential temperature, the convergence field, the moisture convergence and the topography. In Case 2010 (30 December 2010), OSTIA had the best numerical simulation with diverse atmospheric conditions, and the maximum difference in the numerically simulated snowfall between NCEP/NCAR SST and OSTIA was 20 cm. Although there was a regional difference in the snowfall according to the difference in the SST, OSTIA and RTG SST numerical tests, it was not as significant as in the previous results. A higher SST led to the numerical simulation of larger snowfall, and the difference was greatest near Buan in the west coast area.

표층 해상의 기포가 음파전달에 미치는 영향 (The Effects of Ocean Surface Bubbles on Sound Wave Transmission)

  • 임병욱;심태보;김영규;박정수
    • 한국음향학회지
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    • 제28권3호
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    • pp.187-197
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    • 2009
  • 해양에서는 파도, 빗방울 등 해수면에 일어나는 많은 물과 물의 충돌, 해양에서 운행되는 선박, 여러 해양 생물들의 생명활동 그리고 여러 발생 원들에 의해 많은 기포들이 생성될 수 있다. 이렇게 생성된 기포들은 해양에서 사용되는 음파의 세기와 음속에 영향을 미치게 된다. 본 연구에서는 2007년 9월 19일 04:00 부터 17:00 까지 남해 남형제도 해역에서 Acoustic Bubble Spectrometer (ABS)와 CTD를 사용하여 해양 기포생성과 생성기포가 음파에 미치는 영향을 관측하였다. 관측자료를 통하여 풍속과 기포생성의 연관성, 기포의 반경에 따른 기포량, 주파수별 음속비를 분석하였다. 최종적으로 분석자료를 통해 기포가 음파전달에 미치는 영향을 모의하였다.

2007년 태풍 특징 (Characteristics of tropical cyclones over the western North Pacific in 2007)

  • 차은정;박윤호;권혁조
    • 대기
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    • 제18권3호
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    • pp.183-197
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    • 2008
  • The purpose of this study is to summarize tropical cyclone activity in 2007. 24 tropical cyclones of tropical storm (TS) intensity or higher formed in the western North Pacific and the South China Sea in 2007. The total number is less than the thirty-year (1971~2000) average frequency of 26.7. Out of twenty four tropical cyclones, 14 TCs reached typhoon (TY) intensity, while the rest 10 only reached severe tropical storm (STS) and tropical storm (TS) intensity - four STS and six TS storms. The tropical cyclone season in 2007 began in April with the formation of KONG-REY (0701). From April to May, two TCs formed in the western North Pacific in response to enhanced convective activity there. From June to July, convective activity turned inactive over the sea around the Philippines and in the South China Sea, and the subtropical high was weak over the south of Japan. MAN-YI (0704) and USAGI (0705) moved northwestward and hit Japan, bringing serious damage to the country. After August, convective activity became enhanced over the sea east of the Philippines, and the subtropical high turned strong over the sea south of Japan. Many TCs, which formed over the sea east of the Philippines and in the South China Sea, moved westward and hit China and Vietnam. PABUK (0706), WUTIP (0707), SEPAT (0708), WIPHA (0712), LEKIMA (0714) and KROSA (0715) brought serious damage to some countries including China, the Philippines and Vietnam. On the other hand, FITOW (0709) and NARI (0711) moved northward, bringing serious damage to Japan and Korea. After HAIYAN (0716), all four TCs except FAXAI (0720) formed over the sea east of $140^{\circ}E$. Three typhoons among them affected Republic of Korea, MAN-YI (0704), USAGI (0705) and NARI (0711). Particularly, NARI (0711) moved northward and made landfall at Goheng Peninsula ($34.5^{\circ}N$, $127.4^{\circ}E$) in 1815 KST 16 September. Due to $11^{th}$ typhoon NARI, strong wind and record-breaking rainfall amount was observed in Jeju Island. It was reported that the daily precipitation was 420.0 mm at Jeju city, Jeju Island on 16 September the highest daily rainfall since Jeju began keeping records in 1927. This typhoon hit the southern part of the Korean peninsula and Jeju Island. 18 people lost their lives, 14,170 people were evacuated and US$ 1.6 billion property damage was occurred.