• Title/Summary/Keyword: Low-altitude

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Preliminary Results of Tissue-Equivalent Proportional Counter (TEPC) Dosimeter for Measuring In-Situ Aviation Radiation

  • Nam, Uk-won;Park, Won-kee;Hwang, Junga;Sohn, Jongdae;Moon, Bongkon;Kim, Sunghwan
    • Journal of Astronomy and Space Sciences
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    • v.37 no.4
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    • pp.249-255
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    • 2020
  • We develop the tissue-equivalent proportional counter (TEPC) type's space radiation dosimeter to measure in-situ aviation radiation. That was originally developed as a payload of small satellite in the low-earth orbit. This dosimeter is based on a TEPC. It is made of an A-150 tissue-equivalent plastic shell of an internal diameter of 6 cm and a thickness of 0.3 cm. TEPC is filled with pure propane at 13.9 torrs to simulate a cell diameter of 2 ㎛. And the associated portable and low power electronics are also implemented. The verification experiments have been performed by the calibration experiments at ground level and compared with Liulin observation at aircraft altitude during the flight between Incheon airport (ICN) and John F. Kennedy airport (JFK). We found that the TEPC dosimeter can be used as a monitor for space radiation dosimeter at aviation altitude based on the verification with Liulin observation.

A Study on the design of Unmanned Autonomous Helicopter for Aerial Monitoring and Control of a Large Size Disaster and Forest Fire (대형재난 및 산불 공중지휘통제용 무인자율헬기 개발에 관한연구)

  • Kim, Jong-Kwon;Kwark, Ji-Hyun;Son, Bong-Sei
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2008.11a
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    • pp.105-110
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    • 2008
  • Unmanned helicopter has several abilities such as vertical take off, hovering, low speed flight at a specific altitude. Such vehicles are becoming popular in actual applications such as search and rescue, aerial reconnaissance and surveillance in the case of a large size disaster and forest fire. In this paper, a flight control system was designed for an unmanned helicopter. This paper was concentrated on describing the systematic design, electronic equipments and their interconnections for realizing the autonomous flight and aerial monitoring. A study on the autonomous waypoint navigation and altitude control performance were performed and tested on a test unmanned helicopter and the performance and the feasibility were represented.

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Taxonomic Studies on Three Caeneressa Species (Lepidoptera: Syntominae) from India with Special Reference to Their External Genitalia

  • Kirti, Jagbir Singh;Singh, Navneet;Joshi, Rahul
    • Animal Systematics, Evolution and Diversity
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    • v.30 no.1
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    • pp.33-38
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    • 2014
  • Caeneressa diaphana muirheadi (Felder) and Caeneressa brithyris (Druce) have been recorded for the first time from India. Further, a new combination viz. Caeneressa melaena (Walker) comb. nov., has also been proposed on the basis of external genitalic features. With these records, genus Caeneressa will be represented by five species from India, Caeneressa diaphana (Kollar), Caeneressa diaphana muirheadi (Felder), Caeneressa brithyris (Druce), Caeneressa melaena (Hampson) and Caeneressa swinhoei (Leech). The studied material was collected from North-Eastern states of India. Caeneressa brithyris (Druce) was collected near riverside at low altitude whereas the other two species were collected at high altitude.

Steady and Unsteady Operating Characteristics of Supersonic Exhaust Diffuser for Altitude Simulation (고도모사용 초음속디퓨져의 정상 및 천이작동특성)

  • Park, Byung-Hoon;Ki, Wan-Do;Lim, Ji-Hwan;Yoon, Woong-Sup
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2006.11a
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    • pp.344-352
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    • 2006
  • Evacuation performance, starting transient, and plume blowback at diffuser breakdown of a straight cylindrical supersonic exhaust diffuser with no externally supplied secondary flow are investigated. Pressure records in the transitional periods are measured by a small-scale cold-gas simulator. Flow-fields evolving in the diffuser-type ejector are solved by preconditioned Favre-averaged Navier-Stokes equations with a low-Reynolds number $k-{\varepsilon}$ turbulence model edited for turbulence compressibility effects. The present RANS method is properly validated with measured static wall pressure distributions and evacuation level at steady operation as well as the pressure records during the transition regime.

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The Effect of Evapotranspiration by Altitude and Observation of Lysimeter (고도에 따른 증발산 효과와 라이시메타 관측)

  • Lee, Bu-Yong;Yang, Sung-Kee;Kwon, Ki-Hoon;Kim, Jae-Bang
    • Journal of Environmental Science International
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    • v.21 no.6
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    • pp.749-755
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    • 2012
  • The effect of elevation and meteorological elements is analyzed in Jeju Island for analysis of evapotranspiration with two different height observation station during 3 years data. The slope of temperature gradient recorded $1.30^{\circ}C$/100 m from the analysis of temperature data. There is much difference evapotranspiration between low elevation and high elevation station because of decrease solar radiation and wind speed with height increase. The evapotranspiration is observed by mini lysimeter at Hankukgonghang. The result of observation is presented 34.2% of global solar radiation changed into evapotranspiration during 4 clear days.

House dust mite fauna in western Anatolia, Turkey

  • Ciftci Ihsan Hakki;Cetinkaya Zafer;Atambay Metin;Kiyildi Nilay;Aycan Ozlem M.;Daldal Nilgun
    • Parasites, Hosts and Diseases
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    • v.44 no.3
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    • pp.259-264
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    • 2006
  • House dust mites play an important role in the pathogenesis of allergic diseases. Many factors may influence mite growth. The presence of mites is related to mean temperature and humidity as well as altitude. The aim of this study was to analyze the mite fauna in 5 regions of western Anatolia, Turkey, that have similar climatic properties with low mean temperature and humidity, but differ in altitude. During the period October-November 2004, house dust was collected from 290 homes in 5 different cities. House dust mites were isolated in 67 (23.1 %) of 290 samples. The family Pyroglyphidae (Astigmata) was present in all positive samples. This study suggests that the selected western Anatolian regions that share similar environmental conditions host similar dust mite populations.

The distribution, characteristics and utilization of Korean native Actinidia Genus

  • Cho, Y.;Cho, H.;Park, M.
    • Korean Journal of Organic Agriculture
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    • v.19 no.spc
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    • pp.30-34
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    • 2011
  • A. arguta is found nationwide whether the altitude is low or high if good drainage is achieved with plenty of water. The distribution of A. polygama seems to be more limited to higher altitude than A. arguta so it can be found in deep valley of highland even in Mt. Halla. A. kolomikta seems rather limited to colder area than A. arguta to Mt. Jiri to the south. Meanwhile, A. rufa is very confined to southern islands including Jeollanamdo and Jeju islands. Some institutes still continue to utilize Korean native Actinidia plants commercially since early 1980's. More collaborative efforts are needed for further development of these plants nationwide.

Species Richness of Aquatic Insects in Wetlands along the Altitudinal Gradient in Jeju, Korea : Test of Rapoport's Rule (고도에 따른 제주 습지 수서곤충의 종풍부성 변화 : Rapoport 법칙의 검정)

  • Jeong, Sang-Bae;Kim, Dong-Soon;Jeon, Hyeong-Sik;Yang, Kyoung-Sik;Kim, Won-Taek
    • Korean journal of applied entomology
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    • v.49 no.3
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    • pp.175-185
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    • 2010
  • The effect of altitude and latitude on biodiversity (or species richness) has been a topic of great interest for many biogeographers for a long time. This study was conducted to examine the dynamics of species richness of aquatic insects along the altitudinal gradient in 24 wetlands on Mt. Halla, Jeju and test the Rapoport's rule. The species richness of aquatic insects monotonically decreased with increasing altitude, showing a significant inverse correlation (r = -0.64). However, the pattern of species richness with altitude showed a hump-shaped relationship, with a peak in species richness at intermediate elevations when the effects of area were removed. The altitudinal range of species tended to increase with increasing altitude, as Rapoport's rule predicts. There was a positive correlation between the altitudinal range size and the midpoint of the range size (Median) except for Hemiptera (Odonata: r = 0.75, Hemiptera: r = -0.22, Coleoptera: r = 0.72, Total: r = 0.55). Also, the extent of average altitudinal range of high-altitude species was 904.3m, and it was significantly wider than a 469.5m of low-altitude species. Consequently, the species richness of aquatic insects in wetlands on Mt. Halla along the altitudinal gradient well supported Rapoport's rule.

Forest Structure in Relation to Altitude and Part of Slope in a Valley Forest at T$\v{o}$kyusan Area (덕유산지역 계곡부의 해발고와 사면부위에 따른 삼림구조)

  • 박인협;문광선;최영철
    • Korean Journal of Environment and Ecology
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    • v.7 no.2
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    • pp.181-186
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    • 1994
  • The Shindae resting place-Jibong valley forest in Tokyusan area was studied to investigate forest structure in relation to altitude and part of slope. Forty eight quadrats were set up in the valley forest along altitude of 750m to 1,247m and part of the slope. Density of trees in tree strata decreased as increasing elevation, and mean DBH of trees in tree strata increased as increasing elevation. With increasing elevation the importance values of Quercus mongolica, Acer mono, Fraxinus mandshurica increased, while those of Quercus serrate, Betula schmidtii decreased. As going from lower part to upper part of the slope, the importance values of Quercus mongolica and Symplocos chinensis for. pilosa increased while those of Cornus controversa and Fruxinus mandshurica decreased. The number of species, species diversity and evenness tended to decreased as increasing elevation. The range of similarity indices between elevation belts, and parts of the slope were 55.3~67.1% and 36.8~71.7%, respectively. According to importance value and cluster analysis, the studied valley forest was classified into four forest communities of Quercu serrata community of lower part of slope of low elevation belt, Quercus mongolica-Quercus serrata community of middle and upper part of slope of low elevation belt, Quercus mongolica-deciduous tree species community of middle and high elevation belt and Quercus mongolica-Rhododendron schzippinbachii community of the top area.

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Orthophoto and DEM Generation Using Low Specification UAV Images from Different Altitudes (고도가 다른 저사양 UAV 영상을 이용한 정사영상 및 DEM 제작)

  • Lee, Ki Rim;Lee, Won Hee
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.34 no.5
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    • pp.535-544
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    • 2016
  • Even though existing methods for orthophoto production using expensive aircraft are effective in large areas, they are drawbacks when dealing with renew quickly according to geographic features. But, as UAV(Unmanned Aerial Vehicle) technology has advanced rapidly, and also by loading sensors such as GPS and IMU, they are evaluates that these UAV and sensor technology can substitute expensive traditional aerial photogrammetry. Orthophoto production by using UAV has advantages that spatial information of small area can be updated quickly. But in the case of existing researches, images of same altitude are used in orthophoto generation, they are drawbacks about repetition of data and renewal of data. In this study, we targeted about small slope area, and by using low-end UAV, generated orthophoto and DEM(Digital Elevation Model) through different altitudinal images. The RMSE of the check points is σh = 0.023m on a horizontal plane and σv = 0.049m on a vertical plane. This maximum value and mean RMSE are in accordance with the working rule agreement for the aerial photogrammetry of the National Geographic Information Institute(NGII) on a 1/500 scale digital map. This paper suggests that generate orthophoto of high accuracy using a different altitude images. Reducing the repetition of data through images of different altitude and provide the informations about the spatial information quickly.