• Title/Summary/Keyword: the influence of wind

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Syndrome Differentiation of Low Back Pain Presented in Uibujeonrok and Donguibogam in Korean Medicine (의부전록(醫部全錄)과 동의보감(東醫寶鑑)에 제시된 한의학적 요통(腰痛) 분류(分類)에 대한 소고(小考))

  • Lim, Hansol;Nam, Donghyun
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.19 no.3
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    • pp.173-184
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    • 2015
  • Objectives The purpose of this study is to understand formation courses of the ten types of LBP (十種腰痛) in Korean medicine through reviewing classic literatures. Methods We summarized sentences describing syndrome differentiation of LBP directly in Uibujeonrok (醫部全錄) and Donguibogam (東醫寶鑑), and then organized similarities and differences among diagnostic factors described in the classic literatures. Results In most of the classics LBP was classified according to the cause but the causes varied depending on the classic literatures. Cheonkeumbang (千金方) tried to suggest a reasonable classification of LBP in a relatively early age. In Dangyesimbeop (丹溪心法) the causes of LBP were divided into 6 factors; qi movement stagnation (氣鬱), dampness-heat (濕熱), kidney deficiency (腎虛), static blood (瘀血), sprain (挫閃) and phlegm accumulation (積痰). It had a lot of influence on the classic literatures published later. Donguibogam was also influenced by the Dangyesimbeop and the ten types of LBP in Donguibogam was similar to the information on the classification shown in Uihakipmun (醫學入門) and Uijongpildok (醫宗必讀). Conclusions We verified universality of the ten types of LBP; kidney deficiency, phlegm-retained fluid (痰飮), food accumulation (食積), sprain, static blood, wind (風), cold (寒), dampness (濕), dampness-heat and qi (氣).

Numerical Simulation of Air Flow and Gas Dispersion around Obstacles

  • Nguyen The-Due;Park Warn-Gyu;Duong Ngoe-Hai
    • 한국전산유체공학회:학술대회논문집
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    • 2003.10a
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    • pp.253-254
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    • 2003
  • Computations of the mean and turbulence flows over three-dimensional hill of conical shape have implemented. Beside the standard ${\kappa}-{\varepsilon}$ , two other modifications proposed by Detering & Etling and Duynkerke for atmospheric applications were also considered. These predictions were compared with the data of a wind tunnel experiment. From the comparison, it was concluded that all three models predict the mean flow velocities equally well while only the Duynkerke's model accurately predicts the turbulence data statistics. It also concluded that there are large discrepancies between model predictions and the measurements near the ground surface. The flow field, which was obtained by using the Duynkerke's modification, was used to simulate gas dispersion from an upwind source. The calculation results are verified based on the measurement data. Modifications of the turbulent Schmidt number were carried out in order to match the measured results. The code was used to investigate the influence of the recirculation zone behind a building of cubical shape on the transport and dispersion of pollutant. For a stack behind and near the obstacle, some conclusions about the effect of the stack height and stack location were derived.

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Numerical Simulation of Air Flow and Gas Dispersion around Obstacles

  • Nguyen The-Duc;Duong Ngoc-Hai;Park Wam-Gyu
    • 한국전산유체공학회:학술대회논문집
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    • 2003.08a
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    • pp.144-151
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    • 2003
  • Computations of the mean and turbulence flows over three-dimensional hill of conical shape have implemented. Beside the standard $\kappa-\epsilon$, two other modifications proposed by Detering & Etling and Duynkerke for atmospheric applications were also considered. These predictions were compared with the data of a wind tunnel experiment. From the comparison, it was concluded that all three models predict the mean flow velocities equally well while only the Duynkerke's model accurately predicts the turbulence data statistics. It also concluded that there are large discrepancies between model predictions and the measurements near the ground surface. The flow field, which was obtained by using the Duynkerke's modification, was used to simulate gas dispersion from an upwind source. The calculation results are verified based on the measurement data. Modifications of the turbulent Schmidt number were carried out in order to match the measured results. The code was used to investigate the influence of the recirculation zone behind a building of cubical shape on the transport and dispersion of pollutant. For a stack behind and near the obstacle, some conclusions about the effect of the stack height and stack location were derive

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Malfunction Detection of High Voltage Equipment Using Microphone Array and Infrared Thermal Imaging Camera (Microphone Array와 열화상 카메라를 이용한 고압설비 고장검출)

  • Han, Sun-Sin;Choi, Jae-Young;Lee, Jang-Myung
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.1
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    • pp.25-32
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    • 2010
  • The paper proposes a hierarchical fault detection method for the high voltage equipment using a microphone array which detects the location of fault and the thermal imaging and CCD cameras which verifies the fault and stores the image, respectively. There are partial arc discharges on the faulty insulators, which generates a specific pattern of sound. Detecting the signal using the microphone array, the location of the faulty insulator can be estimated. The 6th band-pass filter was applied to remove noise signal from wind or external influence. When the mobile robot carries the thermal and CCD cameras to the possible place of the fault insulator, the fault insulators or power transmission wires can be detected by the thermal images, which are caused by the aging or natural erosion. Finally, the CCD camera captures the image of the fault insulator for the record. The detection scheme of fault location using the microphone array and the thermal images have been proved to be effective through the real experiments. As a result of this research, it becomes possible to use a mobile robot with the integrated sensors to detect the fault insulators instead of a human being.

Dynamic Analysis of Topside Module in Lifting Installation Phase

  • Lee, Jong-Hyun
    • Journal of Ocean Engineering and Technology
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    • v.25 no.4
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    • pp.7-11
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    • 2011
  • The installation phase for a topside module suggested can be divided into 9 stages, which include start, pre-lifting, lifting, lifted, rotating, positioning, lowering, mating, and end of installation. The transfer of the topside module from a transport barge to a crane vessel takes place in the first three stages, from start to lifting, while the transfer of the module onto a floating spar hull occurs in the last three stages, from lowering to the end. The coupled multi-body motions are calculated in both calm water and in irregular waves with significant wave height (1.52m), with suggested force equilibrium diagrams. The effects of the hydrodynamic interactions between the crane vessel and barge during the lifting stage have been considered. The internal forces caused by the load transfer and ballasting are derived for the lifting phases. The results of these internal forces for the calm water condition are compared with those in the irregular sea condition. Although the effect of pitch motion on the relative vertical motion between the deck of the floating structure and the topside module is significant in the lifting phases, the internal force induced pitch motion is too small to show its influence. However, the effect of the internal force on the wave-induced heave responses in the lifting phases is noticeable in the irregular sea condition because the transfer mass-induced draught changes in the floating structure are observed to have higher amplitudes than the external force induced responses.

Flow solutions around rectangular cylinders: The question of spatial discretization

  • Corsini, Roberto;Angeli, Diego;Stalio, Enrico;Chibbaro, Sergio;Cimarelli, Andrea
    • Wind and Structures
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    • v.34 no.1
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    • pp.151-159
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    • 2022
  • The aerodynamics of blunt bodies with separation at the sharp corner of the leading edge and reattachment on the body side are particularly important in civil engineering applications. In recent years, a number of experimental and numerical studies have become available on the aerodynamics of a rectangular cylinder with chord-to-thickness ratio equal to 5 (BARC). Despite the interest in the topic, a widely accepted set of guidelines for grid generation about these blunt bodies is still missing. In this work a new, well resolved Direct Numerical Simulation (DNS) around the BARC body at Re=3000 is presented and its results compared to previous DNSs of the same case but with different numerical approaches and mesh. Despite the simulations use different numerical approaches, mesh and domain dimensions, the main discrepancies are ascribed to the different grid spacings employed. While a more rigorous analysis is envisaged, where the order of accuracy of the schemes are kept the same while grid spacings are varied alternately along each spatial direction, this represents a first attempt in the study of the influence of spatial resolution in the Direct Numerical Simulation of flows around elongated rectangular cylinders with sharp corners.

PATH VARIABILITY OF THE CHANGJIANG DILUTED WATER IN SUMMER

  • Yang, Joon-Yong;Cho, Yang-Ki;Chang, Kyung-Il;Suh, Young-Sang
    • Proceedings of the KSRS Conference
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    • v.2
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    • pp.688-691
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    • 2006
  • The current system of the East China Sea, a marginal sea in the northwest Pacific, has a seasonal variation. The Changjiang Diluted Water, Chinese coastal water in the East China Sea, has different seasonal paths. It flows southward along the Chinese coast within a narrow band in winter and does northeastward the Korea/Tsushima Strait in summer, which has been a subject to many researchers. In particular, low salinity in the South Sea of Korea in 1996 and 1998 was in discord with the Changjiang River discharge and the Changjiang Diluted Water seems to play an important role in occurrence of red tide in the South Sea of Korea in 1997 and on the contrary, disappearance in the next year. These facts suggested that the Changjiang Diluted Water does not flow along the same path in every summer. According to the analyses for path of the Changjiang Diluted Water using ocean color images by SeaWiFS and salinity observations by shipboard CTD in August for recent years, the Changjiang Diluted Water in summer flowed within the range of direction from southeastward to north-northeastward anticlockwise. However, the Changjiang Diluted Water flowed northeastward toward Jeju Island of Korea for the most part. It is necessary to examine the influence of major factors on path variability of the CDW in summer such as surface wind, the Changjiang River discharge and background current.

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A Study on the Characteristics of Sunglint in LongWave InfraRed Band (원적외선 대역의 태양 직사광 해수면 반사신호 특성 연구)

  • Kim, Kyung Ha
    • Journal of the Korea Institute of Military Science and Technology
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    • v.21 no.3
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    • pp.306-314
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    • 2018
  • In maritime environment, it is necessary to understand the characteristics of sunglint since it may degrade the target detection performance of the infrared sensor mounted weapons. In this paper, sunglint in LWIR band is modeled using the slope distribution of the sea surface, and is verified by comparing the radiance of a simulated result with that of the real world. According to the simulation, sunglint is critical when the solar zenith angle is over $60^{\circ}$. The peak radiance of sunglint grows as the solar zenith angle increases until it reaches $83^{\circ}$ and has a large difference depending on the solar zenith angle when the wind speed is small. Finally, seasonal and temporal characteristics of sunglint effects are analyzed. In summer, sunglint is dominant in the horizon near the solar azimuth right after sunrise and before sunset. However, in winter, the influence of sunglint lasts even during the daytime since the elevation of the sun is much lower than in summer.

Experimental Study for Influence of Summertime Heat Sources and Basic States on Rossby Wave Propagation (여름철 열원과 기본장이 로스비 파동전파에 미치는 영향에 대한 실험 연구)

  • Kim, Seong-Yeol;Ha, Kyung-Ja;Yun, Kyung-Sook
    • Atmosphere
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    • v.20 no.4
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    • pp.505-518
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    • 2010
  • We investigated the impacts of the diabatic heating location, vertical profile and basic state on the Rossby wave propagation. To examine the dynamical process of individual responses on the regional heat source, a dry version of the linear baroclinic model was used with climatological summertime (JJA) mean basic state and vertical structure of the diabatic heating for 1979-2008. Two sets of diabatic heating were constructed of those positioned in the mid-latitudes (Tibetan Plateau, eastern Mediterranean Sea, and the west-central Asia) and the tropics (the southern India, Bay of Bengal, and western Pacific). It was found that using the principal component analysis, atmospheric response to diabatic heating reaches to the steady state in 19th days in time. The prescribed mid-latitude forcing forms equivalent barotropic Rossby wave propagation along the westerly Asia jets, whereas the tropical forcing generates the Rossby wave train extending from the tropics to mid-latitudes. In relation to the maximum vertical profile, the mid-level forcing reveals a stronger response than the lower-level forcing, which may be caused by more effective Rossby wave response by the upper-level divergent flow. Under the different sub-seasonal mean state, both of the tropical and mid-latitude forcing induce the different sub-seasonal response intensity, due to the different basic-state wind.

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

  • Park, Geon-Young;Ryu, Chan-Su
    • Journal of Integrative Natural Science
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    • v.7 no.1
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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.