• Title/Summary/Keyword: wind data

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Numerical Simulation of Extreme Air Pollution by Fine Particulate Matter in China in Winter 2013

  • Shimadera, Hikari;Hayami, Hiroshi;Ohara, Toshimasa;Morino, Yu;Takami, Akinori;Irei, Satoshi
    • Asian Journal of Atmospheric Environment
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    • v.8 no.1
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    • pp.25-34
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    • 2014
  • In winter 2013, extreme air pollution by fine particulate matter ($PM_{2.5}$) in China attracted much public attention. In order to simulate the $PM_{2.5}$ pollution, the Community Multiscale Air Quality model driven by the Weather Research and Forecasting model was applied to East Asia in a period from 1 January 2013 to 5 February 2013. The model generally reproduced $PM_{2.5}$ concentration in China with emission data in the year 2006. Therefore, the extreme $PM_{2.5}$ pollution seems to be mainly attributed to meteorological (weak wind and stable) conditions rather than emission increases in the past several years. The model well simulated temporal and spatial variations in $PM_{2.5}$ concentrations in Japan as well as China, indicating that the model well captured characteristics of the $PM_{2.5}$ pollutions in both areas on the windward and leeward sides in East Asia in the study period. In addition, contribution rates of four anthropogenic emission sectors (power generation, industrial, residential and transportation) in China to $PM_{2.5}$ concentration were estimated by conducting zero-out emission sensitivity runs. Among the four sectors, the residential sector had the highest contribution to $PM_{2.5}$ concentration. Therefore, the extreme $PM_{2.5}$ pollution may be also attributed to large emissions from combustion for heating in cold regions in China.

Cyberspace Coordinate Create for Augmented Reality (증강현실을 위한 가상 공간좌표 생성)

  • Ban, KyeongJin;Ryu, NamHoon;Kim, KyeongOk;Han, JeaJung;Kim, EungKon
    • Proceedings of the Korea Contents Association Conference
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    • 2009.05a
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    • pp.765-769
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    • 2009
  • The Augmented Reality of existing for the interaction which the object and background is smooth used the data glove or marker. It is inconvenient to a use and it occurs the result of immersion feeling decrease. Immersion it will wind from Augmented Reality and the hazard which it strengthens the removal of the additional entry device which stands is necessary. It recognizes the space coordinates which is accurate even from the condition where the hazard marker which will reach does not attach in necessity. Immersion feeling improvement from Augmented Reality wearing the hazard additional entry device it proposes the space coordinate creation technique of the virtuality description below for a interaction without from the present paper. The method which is proposed the image which it acquires the object of virtuality reflected at 2D space and the characteristic line about under extracting the space coordinate which reflects about under calculating it reflected. The application is possible in markerless Augmented Reality and the mobile Augmented Reality.

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A Selection of the Refuge Area in the West Sea for the National Fishery Supervision Vessel according to the Trajectories of the Extratropical Cyclone in Winter Season (겨울철 온대저기압의 이동경로에 따른 국가어업지도선의 서해 피항지 선정)

  • Chong, Ki-Chol;Seol, Dong-Il
    • Journal of Navigation and Port Research
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    • v.31 no.6
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    • pp.555-562
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    • 2007
  • The environs of Korea in winter season are influenced by the distribution of atmospheric pressure, namely, the typical east-low and west-high pattern that is formed from both the Siberian continental high pressure and the Aleutian oceanic low pressure. In this reason, the violent West or North-West monsoon, the billows with the strong wind, and the tremendous heavy snowfall are encountered very frequently in the West Sea. In this study, the trajectories of the extratropical cyclone are analysed to choose the safe refuge areas of National Fishery Supervision Vessel using the surface analysis weather chart for 11 years from 1994 to 2004. The safe refuge areas according to the trajectories of the extratropical cyclone in the West Sea are decided using data that contain the topographical properties of island, the depth of water, the state of low quality, the influence of tidal current, and the distribution of fishing-net.

Ballast Flying Probability Analysis for Ballast Types and Underbody Flow Conditions (자갈 종류 및 하부 유동 조건에 따른 자갈비산 확률 분석)

  • Rho, Joo-Hyun;Ku, Yo-Cheon;Yun, Su-Hwan;Park, Hoon-Il;Kwon, Hyeuk-Bin;Lee, Dong-Ho
    • Journal of the Korean Society for Railway
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    • v.12 no.6
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    • pp.829-834
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    • 2009
  • A ballast-flying probabilitie is suggested for various ballast types, heighter types and underbody flow conditions as train speeds. The average speed of measured points is converted to the ballast-flying probabilities of BFPF which come from wind tunnel test data. Underbody flow fields are numerically simulated for the various conditions. The results show that the ballast-flying probability is steeply increased as train speed increased, and reaches a value of 87% at 350 km/h train speed. And the differences of probabilities among the ballast shapes are considerably high. The upper surface of heighter or tie is most probable area. Through this study, the ballast-flying Sensitivities with heighter was defined to understand the characteristics of ballast-flying probability on various conditions. And the ballast-flying probability can be reduced by the heighter.

LARGE-SCALE VERSUS EDDY EFFECTS CONTROLLING THE INTERANNUAL VARIATION OF MIXED LAYER TEMPERATURE OVER THE NINO3 REGION

  • Kim, Seung-Bum;Lee, Tong;Fukumori, Ichiro
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.21-24
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    • 2006
  • Processes controlling the interannual variation of mixed layer temperature (MLT) averaged over the NINO3 domain ($150-90^{\circ}W$, $5^{\circ}N-5^{\circ}S$) are studied using an ocean data assimilation product that covers the period of 1993 to 2003. Advective tendencies are estimated here as the temperature fluxes through the domain's boundaries, with the boundary temperature referenced to the domain-averaged temperature to remove the dependence on temperature scale. The overall balance is such that surface heat flux opposes the MLT change but horizontal advection and subsurface processes assist the change. The zonal advective tendency is caused primarily by large-scale advection of warm-pool water through the western boundary of the domain. The meridional advective tendency is contributed mostly by Ekman current advecting large-scale temperature anomalies though the southern boundary of the domain. Unlike many previous studies, we explicitly evaluate the subsurface processes that consist of vertical mixing and entrainment. In particular, a rigorous method to estimate entrainment allows an exact budget closure. The vertical mixing across the mixed layer (ML) base has a contribution in phase with the MLT change. The entrainment tendency due to temporal change in ML depth is negligible comparing to other subsurface processes. The entrainment tendency by vertical advection across the ML base is dominated by large-scale changes in wind-driven upwelling and temperature of upwelling water. Tropical instability waves (TIWs) result in smaller-scale vertical advection that warms the domain during La Ni? cooling events. When the advective tendencies are evaluated by spatially averaging the conventional local advective tendencies of temperature, the apparent effects of currents with spatial scales smaller than the domain (such as TIWs) become very important as they redistribute heat within the NINO3 domain. However, such internal redistribution of heat does not represent external processes that control the domain-averaged MLT.

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Evaluation of the Performance of Water Quality Models for the Simulation of Reservoir Flushing Effect on Downstream Water Quality (저수지 플러싱 방류가 하류 수질에 미치는 영향 모의를 위한 수질모델의 성능 평가)

  • Jung, Yong Rak;Chung, Se Woong;Yoon, Sung Wan;Oh, Dong Geun;Jeong, Hee Young
    • Journal of Korean Society on Water Environment
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    • v.25 no.1
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    • pp.48-57
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    • 2009
  • A two-dimensional (2D), laterally-averaged hydrodynamic and water quality model, CE-QUAL-W2 was applied to evaluate the performance on simulating the effect of flushing from Daecheong Reservoir on the downstream water quality variations during the flushing events held on November, 2003 and March, 2008. The hydraulic and water quality simulation results were compared with field measurement data, as well as a one-dimensional (1D), unsteady model (KORIV1) that revealed limited capability in the previous study due to missing the resuspension process of river bottom sediments. The results showed that although the 2D model made satisfactory performance in reproducing the temporal variations of dissolved matters including phosphate, ammonia and nitrate, it revealed poor performance in simulating the increase of biological oxygen demand and suspended sediment (SS) concentrations during the passage of the flushing flow. The reason of the error was that the resuspension process of the 2D model is only the function of shear stress induced by wind. In reality, however, as shown by significant correlation between bottom shear stress ($\tau$) and observed SS concentration, the resuspension process can be significantly influenced by current velocity in the riverine system, especially during flushing event. The results indicate that the resuspension of river bottom materials should be incorporated into the water quality modeling processes if $\tau$ is greater than a critical shear stress (${\tau}_c$) for better simulation of flushing effect.

Winter Warming and Long-term Variation in Catch of Yellowtail (Seriola quinqueradiata) in the South Sea, Korea (겨울철 온난화와 남해 방어 어획량의 장기변동)

  • Lee, Seung-Jong;Go, You-Bong
    • Korean Journal of Ichthyology
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    • v.18 no.4
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    • pp.319-328
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    • 2006
  • The relationships among long-term climate variation at the southern part of the Korean peninsula, oceanic conditions in the South Sea, Korea, and variation in the winter catch of yellowtail (Seriola quinqueradiata) were analyzed using 32 years of time-series data from 1971~2002. In the early 1990s, winter climatic conditions at the southern part of Korean peninsula shifted from a cool to a warm regime with higher air temperature, relative weak wind speed, and lower relative humidity. Also, the winter water temperature at 50 m depth became consistently higher in the South Sea. The annual winter catch of yellowtail in the South Sea increased dramatically in the early 1990s, as did that of anchovy, which is the major food organism for yellowtail. From the results of correlation analysis, we found that the winter catch of yellowtail was more closely related to the increasing of air temperature, water temperature and anchovy catch.

A Study of Sensor Fusion using Radar Sensor and Vision Sensor in Moving Object Detection (레이더 센서와 비전 센서를 활용한 다중 센서 융합 기반 움직임 검지에 관한 연구)

  • Kim, Se Jin;Byun, Ki Hun;Won, In Su;Kwon, Jang Woo
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.16 no.2
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    • pp.140-152
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    • 2017
  • This Paper is for A study of sensor fusion using Radar sensor and Vision sensor in moving object detection. Radar sensor has some problems to detect object. When the sensor moves by wind or that kind of thing, it can happen to detect wrong object like building or tress. And vision sensor is very useful for all area. And it is also used so much. but there are some weakness that is influenced easily by the light of the area, shaking of the sensor device, and weather and so on. So in this paper I want to suggest to fuse these sensor to detect object. Each sensor can fill the other's weakness, so this kind of sensor fusion makes object detection much powerful.

Power Estimation and Optimum Design of a Buoy for the Resonant Type Wave Energy Converter Using Approximation Scheme (근사기법을 활용한 공진형 파력발전 부이의 발전량 추정 및 최적설계)

  • Koh, Hyeok-Jun;Ruy, Won-Sun;Cho, Il-Hyoung
    • Journal of Ocean Engineering and Technology
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    • v.27 no.1
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    • pp.85-92
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    • 2013
  • This paper deals with the resonant type of a WEC (wave energy converter) and the determination method of its geometric parameters which were obtained to construct the robust and optimal structure, respectively. In detail, the optimization problem is formulated with the constraints composed of the response surfaces which stand for the resonance period(heave, pitch) and the meta center height of the buoy. Use of a signal-to-noise ratio calculated from normalized multi-objective results with the weight factor can help to select the robust design level. In order to get the sample data set, the motion responses of the power buoy were analyzed using the BEM (boundary element method)-based commercial code. Also, the optimization result is compared with a robust design for a feasibility study. Finally, the power efficiency of the WEC with the optimum design variables is estimated as the captured wave ratio resulting from absorbed power which mainly related to PTO (power take off) damping. It could be said that the resultant of the WEC design is the economical optimal design which satisfy the given constraints.

A study on the site analysis considering a fused relationship of the architectural site and surrounding context (건축대지와 주변 컨텍스트의 융합적인 연계성을 고려한 대지분석에 관한 연구)

  • Jun, In-Mok
    • Journal of the Korea Convergence Society
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    • v.8 no.5
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    • pp.275-285
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    • 2017
  • The architectural site exists in the context of the surrounding environment as the background of architectural design, and the architecture exists in the connection between the site and the surrounding environment therefore, the plan of the building starts from the analysis of the site, and its consequences too meaning can be found in the relation with the surrounding environment. Ironically, however, there are no direct papers describing site analysis with this meaning. Therefore, this paper categorizes the site analysis items around the four environments of Land, Water, Fire, and Wind that constitute the environment of the ecosystem, furthermore, in order to apply the result of the fusion information to the architectural design by synthesizing the organic correlation between the inside and the surrounding environment, i created the '9sectors system', which is a combination of 'horizontal 3 and vertical 3' to provide a more rational and efficient architectural plan. Through the progress of the project using this system, it is considered that it is a more applicable method of the site analysis data than the existing site analysis method.