• 제목/요약/키워드: wind circulation

검색결과 329건 처리시간 0.026초

다연동 온실의 자연환기효율성 비교 분석 (Comparative Study on Efficiencies of Naturally-Ventilated Multi-Span Greenhouses in Korea)

  • 권순홍;정성원;권순구;박종민;최원식;김종순
    • 한국산업융합학회 논문집
    • /
    • 제20권1호
    • /
    • pp.8-18
    • /
    • 2017
  • This research analyzed the ventilation effect of the multi-span greenhouse based on the types of greenhouse structure, weather conditions, and locations inside the greenhouse. To compare and analyze the ventilation effects with different types of greenhouse, the uniform environmental conditions should be selected in advance. But these factors are not controlled and require tense many precision facilities and labor forces. Thus, the CFD simulation was used for the air stream to be analyzed qualitatively and quantitatively. In addition, for the ventilation effect analysis, the TGD (Tracer Gas Decay) was used to overcome the shortcomings of the current ventilation measurement method. The calculation error of ventilation rate using TGD was low (10.5%). Thus, the TGD is very effective in calculating the ventilation efficiency. The wind direction of 90 degrees showed the best ventilation effect. The ventilation rate also decreased along the air circulation path, and the rate was the lowest around the outlet. The computed fluid method (CFD) turned out to be a power tool for simulating flow behavior in greenhouse.

지구 대기가 지구 기준계에 미치는 영향 : 기존 모델 분석 (Effects of Earth's Atmosphere on Terrestrial Reference Frame : A Review)

  • 나성호;조정호
    • 지구물리와물리탐사
    • /
    • 제18권3호
    • /
    • pp.133-142
    • /
    • 2015
  • 지구대기압력이 지각에 변위를 일으키는 현상은 오래 전부터 인식되었으며, 근래의 측지-측량, 특히 우주측지에서 이의 정확한 산정이 필요하게 되었다. 육지에서의 대기 하중에 의한 변형은 주어진 대기압 분포와 하중함수로부터 바로 계산할 수 있으며, 해양에 근접한 지역에서는 근사적인 모델이 사용되고 있다. 지구 대기대순환의 변화와 계절별 지구 양반구에서의 대기압의 분포의 변화들이 각각 지구자전속도 변화와 극운동의 가장 큰 요인으로 알려져 있으며, 바람과 대기압의 변화는 여러 주기영역에서 지구상의 지점들의 좌표의 섭동 및 지구자전상태의 큰 변화 요인이 되고 있다. 본 연구에서는 이와 같은 현상들을 기술하며 관련된 이론과 모델들을 요약하고, 또한 한반도를 지나가는 가상적인 태풍에 의한 효과를 예시하였다. 마지막으로 관련된 몇몇 문제점들과 향후 연구방향을 논의하였다.

황해의 리용과 재난방지를 위한 해양학적 과제와 국제협력 (Oceanographic Tasks and International Coorperations for the Utilization and Disaster Prevention of the Yellow Sea)

  • 오임상
    • 한국해양학회지
    • /
    • 제28권4호
    • /
    • pp.339-346
    • /
    • 1993
  • 인구의 절대적 증가와 공업단지 등이 해안 지역에 편중되므로써 해안선 및 연안의 이용율이 급격히 증가하였으며 이러한 추세는 당분간 멈추지 않을 것으로 확신한다. 따라서 같은 강도를 갖는 재난이 닥친다고 하더라도 과거와 현재를 비교할 때 인적, 물적 피해는 훨씬 더 늘어날 수밖에 없다. 황해의 적절한 이용과 빈번히 발생하는 해 난이나 재해 방지와 예방, 그리고 연안오염 및 유류오염 등에 대한 대처를 위한 철저 한 연구가 필요하다. 이에 해양학적인 관점에서 황해의 해수순환, 조류, 해일, 해상 풍, 파랑, 해무등의 연구가 필수적으로 선행되어야 하며 이를 바탕으로 유류나 오염물 질의 분산과 확산, 해안침식, 적조현상, 해수면 장기변동 등을 연구할 수 있을 것이 다. 또한 이러한 연구를 위해서는 제 해양현상의 특성인 시·공간적인 규모 때문에 국 제협력이 필수적으로 요청된다.

  • PDF

금궤요략.혈비허로병맥증병치제육(血痺虛勞病脈證幷治第六)에 대한 연구 (Study on the 'Pulse Syndrome Complex and Treatment of Blood Paralysis and Weakness Fatigue' in The Synopsis of Golden Chamber)

  • 천상묵;한성규;여성원;이윤천;소용섭;노승조;정헌영
    • 동의생리병리학회지
    • /
    • 제20권2호
    • /
    • pp.333-344
    • /
    • 2006
  • The Blood paralysis(血痺) is infected by a poisonous factor of wind and it disturbs the circulation of meridian. This disease is similar phenomenon to the Blutsaure(血柱) and belongs to the category like the Radial nerve paralysis, the Ulna nerve paralysis and the unstability syndrome of the lower limbs. This dissertation will inquire into symptoms, the way of treatment and the prescriptions of this disease based on the Synopsis of Golden Chamber. The Weakness and fatigue(虛勞) is occurred by several causes. This disease means all the functions of body weakened. This dissertation will inquire into pulse conditions according to the type of the Weakness and fatigue(虛勞), symptoms, the way of treatment and the prescriptions of this disease based on the Synopsis of Golden Chamber.

한국남서해의 열 에너지 이용 (Utilization of Energy in the Sea Water of the Southeastern Yellow Sea)

  • 장선덕
    • 수산해양기술연구
    • /
    • 제14권2호
    • /
    • pp.113-116
    • /
    • 1978
  • 우리나라 근해의 열 에너지 이용 가능성을 알기 위하여 황해 동부해역의 연직온도차 분포상황 및 그 계절적 변동을 조사하였고, 이들과 해수유동과의 관련성에 관하여 고찰하였다. 하계에는 거안 약 40mile 해역인 125${\circ}$30'E 이서의 34${\circ}$N이북에 연직온도차가 16$^{\circ}C$ 이상 되는 곳이 존재하는 바, 이것은 따뜻한 황해 난류계수의 표면가열과 저층의 황해냉수에 기인하는 것으로 생각된다. 연안으로 갈수록 연직 온도차는 줄어지고, 거안 약 30mile 해역에서는 약 1$0^{\circ}C$이다. 이를 이용하여 온도차발전이 가능하다고 보아진다. 제주도 남부 및 서부해역은 연직 온도차가 약 14$^{\circ}C$ 이상을 보인다. 겨울에는 왕성한 대류혼합으로 연직 온도차는 거의 없어진다. 그러나 겨울에는 강한 계절풍이 계속 발전체계를 여름에는 온도차발전, 겨울에는 파력 및 풍력발전을 하는 방식으로 체계화하면 주년 계속 발전이 가능할 것이라 생각된다.

  • PDF

효율적인 어업실습선의 선교 layout을 위한 당직항해사의 업무특성 분석 (Analysis characteristics of officers' watch-keeping for efficient navigation bridge layout of a fisheries training vessel)

  • 김민선;황보규
    • 수산해양기술연구
    • /
    • 제52권1호
    • /
    • pp.56-64
    • /
    • 2016
  • This study analyzed characteristics of officers' watch-keeping during fishing operation at the fisheries training ship KAYA (GT: 1,737 tons, Pukyong National University). It observed fishing works of three officers in wheel house of KAYA. The observations were carried out at the fishing ground 45 miles away from east of Jeju from 7 to 8 January 2010. The works and movements of the officers were recorded with three common video cameras and a 4-channel MPEG-4 Triplex DVR. Recorded data of the working circulation was analyzed by using the post-processing method. As a result of the traffic lines, the average (${\pm}S.D$) of working hour (min) and moving frequency (times), distance (m) and speed (m/min) during setting the net was 11.8 (0.9), 43.7 (8.1), 133.9 (35.8) and 10.5 (0.6), respectively. During trawling the net, it was 100, 241 (39.8), 615.7 (194.6) and 5.2 (1.6), respectively. During hauling the net, it was 17.6 (1.4), 41.0 (7.2), 196.9 (37.6) and 10.7 (0.8), respectively. In addition, it has a different tendency of the instrument usage frequency by the fishing works. During setting, the usage priority was CCTV, ECDIS, RPM and pitch controller, net monitor, GPS plotter, chart room, X-band radar, fish finder and public addressor. During trawling, it was CCTV, ECDIS, fish finder, X-band radar, net monitor, chart room, GPS plotter, RPM and pitch controller, auto pilot and steering, interphone, wind speed and direction indicator, No.1. VHF, navigation light control panel and public addressor. During hauling, it was CCTV, RPM and pitch controller, GPS plotter, public addressor, chart room, net monitor, X-band radar, auto pilot and steering and fish finder.

Numerical Case Study of Heavy Rainfall Occurred in the Central Korean Peninsula on July 26-28, 1996

  • Kim, Young-Ah;Oh, Jai-Ho
    • International Union of Geodesy and Geophysics Korean Journal of Geophysical Research
    • /
    • 제26권1호
    • /
    • pp.15-29
    • /
    • 1998
  • The numerical simulation of heavy precipitation event occurred in the central Korean Peninsula on July 26-28, 1996 was performed using the fine mesh model. ARPS (Advanced Regional Prediction System) developed by the CAPS (Center for Analysis and Prediction of Storms). Usually, the heavy rainfalls occurred at late July in the Korean Peninsula were difficult to predict, and showed very strong rainfall intensity. As results, they caused a great loss of life and property. As it usual, this case was unsuccessful to predict the location of rain band and the precipitation intensity with the coarse-mesh model. The same case was, however, simulated well with fine-mesh storm-scale model, ARPS. Moisture band at 850 hPa appeared along the Changma Front in the area of China through central Korea passed Yellow Sea. Also the low-level jet at 700 hPa existed in the Yellow Sea through central Korea and they together offered favorable condition to induce heavy rainfall in that area. The convective activities developed to a meso-scale convective system were observed at near the Yangtze River and moved to the central Korean Peninsula. Furthermore, the intrusion of warm and moist air, origninated from typhoon, into the Asia Continent might result in heavy rainfall formation through redistribution of moisture and heat. In the vertical circulation, the heavy rainfall was formed between the upper- and low-level jets, especially, the entrance region of the upper-level jet above the exit the region of the low-level jet. The low level convergence, the upper level divergence and the strong vertical wind were organized to the very north of the low level jet and concentrated on tens to hundreds km horizontal distance. These result represent the upper- and low-level jets are one of the most important reasons on the formation of heavy precipitation.

  • PDF

Recycling of Suspended Particulates by Atmospheric Boundary Depth and Coastal Circulation

  • Choi, Hyo
    • 한국환경과학회:학술대회논문집
    • /
    • 한국환경과학회 2003년도 International Symposium on Clean Environment
    • /
    • pp.19-26
    • /
    • 2003
  • The dispersion of recycled particulates in the complex coastal terrain containing Kangnung city, Korea was investigated using a three-dimensional non-hydrostatic numerical model and lagrangian particle model (or random walk model). The results show that particulates at the surface of the city that float to the top of thermal internal boundary layer (TIBL) are then transported along the eastern slope of the mountains with the passage of sea breeze and nearly reach the top of the mountains. Those particulates then disperse eastward at this upper level over the coastal sea and finally spread out over the open sea. Total suspended particulate (TSP) concentration near the surface of Kangnung city is very low. At night, synoptic scale westerly winds intensify due to the combined effect of the synoptic scale wind and land breeze descending the eastern slope of the mountains toward the coast and further seaward. This increase in speed causes development of internal gravity waves and a hydraulic jump up to a height of about 1km above the surface over the city. Particulate matter near the top of the mountains also descends the eastern slope of the mountains during the day, reaching the central city area and merges near the surface inside the nocturnal surface inversion layer (NSIL) with a maximum ground level concentration of TSP occurring at 0300 LST. Some particulates were dispersed following the propagation area of internal gravity waves and others in the NSIL are transported eastward to the coastal sea surface, aided by the land breeze. The following morning, particulates dispersed over the coastal sea from the previous night, tend to return to the coastal city of Kangnung with the sea breeze, developing a recycling process and combine with emitted surface particulates during the morning. These processes result in much higher TSP concentration. In the late morning, those particulates float to the top of the TIBL by the intrusion of the sea breeze and the ground level TSP concentration in the city subsequently decreases.

  • PDF

Long-range Transport Mechanisms of Asian Dust associated with the Synoptic Weather System

  • Kim, Yoo-Keun;Lee, Hwa-Woon;Moon, Yun-Seob;Song, Sang-Keun
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
    • /
    • 제10권S_4호
    • /
    • pp.197-206
    • /
    • 2001
  • The long-range transport mechanisms of Asian dust were analyzed based on the synoptic weather system and numerical simulation by using NCEP/NCAR reanalysis and TOMS data during the periods of 1996-2001. We classified the whole weather types of eastern Asia during spring and created the representative weather types during the yellow sand events using cluster analysis and weather charts for the last 6 years(1996~2001). These long-range transport mechanisms were related to various pressure patterns including high and low, trough and ridge, and upper-level fronts. Case studies of the yellow sand events have performed by the simulation of MM5 with meteorological elements such as the horizontal wind of u and v component, potential temperature, potential vorticity, and vertical circulation during the episodic days(2~8 March 2001). In addition, the origin of the long-range transport was examined with the estimation of backward trajectory using HYSPLIT4 Model. In this paper, we concluded that three weather types at 1000 hPa, 850 hPa, 500 hPa, and 300 hPa levels were classified respectively. The dominant features were the extending continental outflow from China to Korea at 1000 hPa and 850 hPa levels, the deep trough passage and cold advection at 500 hPa and 300 hPa levels during the yellow sand events. And also, we confirmed the existence of pola $r_tropical jets in the upper-level, the behavior of potential vorticity over Korea, the estimation of potential vorticity through vertical cross section, and the transport of yellow sand through backward trajectories.es.

  • PDF

혈전증(血栓症) 및 고점도혈증(高粘度血症)에 대(對)한 당귀음(當歸飮)과 이진탕(二陳湯)의 실험적(實驗的) 연구(硏究) (Studies on the Effects of Danggieum and Ijintang on Thrombosis and Elevated Blood Viscosity)

  • 김영석
    • 대한한의학회지
    • /
    • 제15권2호
    • /
    • pp.212-232
    • /
    • 1994
  • I selected the theory of blood stasis and wetness-phlegm among the major 4 causes of Joong Poong(C.V.A.)(wind. fire. deficiency of vital energy and wetness-phlegm) and recent etiology of blood stasis. An experimental studies were done to investigate the effects of Danggieum (removing blood stasis and promoting blood circulation) and Ijintang(dissipating wetness-phlegm) on thrombosis and elevated blood viscosity. The results were as follows; 1. The number of platelets were significantly increased in only Danggieum group. 2. Related to the amount of fibrinogen. only Danggieum group revealed some increase. but both groups revealed no significance. 3. Related to the prothrombin time. Danggieum and Ijintang groups had significant decrease. but Danggieum group revealed more significance. 4. Related to the degree of concentration of FDP, only Danggieum group had significant decrease. 5. Whole blood viscosity and plasma viscosity in lower shear rates. both groups of Danggieum and Ijintang had significant decrease. 6. Related to the amount of RBC. both groups of Danggieum and Ijintang had significant decrease. 7. Related to the change of hematocrit. only Danggieum group, and the change of hemoglobin. only Ijintang group had significant decrease. 8. Related to the change of body temperature. only Ijintang group had significant raise. 9. Related to the changes of WBC. glucose, albumin, total protein and body weight. Danggieum and Ijintang groups had each increase or decrease. but no significance. According to the above results, Danggieum had more significant effect than Ijintang on the thrombosis. and Ijintang had more significant effect than Danggieum on the elevated blood viscosity. And it is considered that it might be more effective in treating Joong-Poong(C.V.A) to take medicines regarding patient's constitution and symptoms as well as the causes of Joong-Poong(C.V.A)

  • PDF