• Journal of Environmental Science International
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• v.14 no.2
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• pp.141-156
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• 2005

The importance of atmospheric conditions for the assessment of an air pollution situation has been demonstrated by their influence on the various compartments of an air pollution system, comprising all stages from emission to effects. Especially, air pollutants dispersion phenomenon are very sensitive according to wind data. But the discussions of how to apply representative meteorological data in air pollution dispersion model are not frequent in Korean environmental assessment processes. In this study, we investigated the difference of air pollutants dispersion phenomenon using U.S EPA ISCLT3 model according to applying the different meteorological data observed at two points for Seongseo industrial complex of Daegu. Two points are the spot site of Seongseo industrial complex and Daegu meteorological observatory. The winds speed of the spot site were smaller than those of Daegu meteorological observatory. In the winter season, the differences came to about $64\%$ for the period$(I\;February\;2001\~31\;January\;2002)$. Wind directions were also fairly different at two points. The air pollutants dispersion phenomenon estimated from our numerical experiments were also fairly different owing to the meteorological conditions at two points.

• Wind and Structures
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• v.27 no.5
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• pp.293-309
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• 2018

The prediction of multimode flutter relies, to a larger extent than bimodal flutter, on accurate modeling of the self-excited forces since it is challenging to perform experimental validation by using aeroelastic tests for a multimode case. This paper sheds some light on the accuracy of predicted self-excited forces by comparing numerical predictions of self-excited forces with measured forces from wind tunnel tests considering the flutter vibration mode. The critical velocity and the corresponding flutter vibration mode of the Hardanger Bridge are first determined using the classical multimode approach. Then, a section model of the bridge is forced to undergo a motion corresponding to the flutter vibration mode at selected points along the bridge, during which the forces that act upon it are measured. The measured self-excited forces are compared with numerical predictions to assess the uncertainty involved in the modeling. The self-excited lift and pitching moment are captured in an excellent manner by the aerodynamic derivatives. The self-excited drag force is, on the other hand, not well represented since second-order effects dominate. However, the self-excited drag force is very small for the cross-section considered, making its influence on the critical velocity marginal. The self-excited drag force can, however, be of higher importance for other cross-sections.

• Atmosphere
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• v.18 no.4
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• pp.485-492
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• 2008

This study confirms that a decadal variation of the SST (Sea Surface Temperature) in the WNP (Western North Pacific) has an influence on the genesis and passage ofa Tropical Cyclone. The decadal mode was obtained by calculating the SST anomaly on the domain $150^{\circ}E-190^{\circ}E$, and $5^{\circ}S-5^{\circ}N$. Such decadal variation was subsequently analyzed to confirm that it is a dominant mode in central Pacific region. Next, after classifying the years into relatively positive years and relatively negative years, the characteristics of Tropical Cyclone in each year, such as a genesis and passage frequency, were investigated. Compared to the relatively negative years, during the relatively positive years, the location of Tropical Cyclone genesis was biased toward South-Eastern region, while the characteristics of the cyclone were more distinct during late season of the year trom September to December than in mid season from June to August. Examining the movement passage through the observation of passage fiequency, there was a significant difference between positive year and negative year in their passages at a 90% confidence level. Moreover, the number of Tropical Cyclone, maximum wind, and life time also showed higher values in positive years than in negative years. These features were confirmed by examining the 850hPa cyclonic flow field, vorticity field, and vertical wind shear field, all of which contribute to the genesis of a Tropical Cyclone.

• Steel and Composite Structures
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• v.21 no.3
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• pp.479-500
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• 2016

Seismic design criteria allow enhancing the structural ductility and controlling the damage distribution. Therefore, detailing rules and design requirements given by current seismic codes might be also beneficial to improve the structural robustness. In this paper a comprehensive parametric study devoted to quantifying the effectiveness of seismic detailing for steel Moment Resisting Frames (MRF) in limiting the progressive collapse under column loss scenarios is presented and discussed. The overall structural performance was analysed through nonlinear static and dynamic analyses. With this regard the following cases were examined: (i) MRF structures designed for wind actions according to Eurocode 1; (ii) MRF structures designed for seismic actions according to Eurocode 8. The investigated parameters were (i) the number of storeys; (ii) the interstorey height; (iii) the span length; (iv) the building plan layout; and (v) the column loss scenario. Results show that structures designed according to capacity design principles are less robust than wind designed ones, provided that the connections have the same capacity threshold in both cases. In addition, the numerical outcomes show that both the number of elements above the removed column and stiffness of beams are the key parameters in arresting progressive collapse.

• Wind and Structures
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• v.32 no.5
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• pp.453-469
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• 2021

Snow accumulation on the road frequently induces a big traffic problem in the cold snowy region. Accurate prediction on snow distribution is fundamental for solving drifting snow disasters on roads. The present study adopts the transient method to simulate the wind-induced snow distribution on embankment based on the mixture multiphase model and dynamic mesh technique. The simulation and field measurement are compared to confirm the applicability of the simulation. Furthermore, the process of snow accumulation is revealed. The effects of friction velocity and snow concentration on snow accumulation are analyzed to clarify its mechanism. The results show that the simulation agrees well with the field measurement in trends. Moreover, the snow accumulation on the embankment can be approximately divided into three stages with time, the snow firstly deposited on the windward side, then, accumulation occurs on the leeward side which induced by the wake vortex, finally, the snow distribution reaches an equilibrium state with the slope of approximately 7°. The friction velocity and duration have a significant influence on the snow accumulation, and the vortex scale directly affected the snow deposition range on the embankment leeward side.

• International Journal of High-Rise Buildings
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• v.2 no.3
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• pp.179-192
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• 2013

The lack of systematic validation for the design process supporting tall buildings motivated the authors' research groups and their collaborators to found the Chicago Full-Scale Monitoring Program over a decade ago. This project has allowed the sustained in-situ observation of a collection of tall buildings now spanning worldwide. This paper overviews this program and the lessons learned in the process, ranging from appropriate technologies for response measurements to the factors influencing accurate prediction of dynamic properties all the way to how these properties then influence the prediction of response using wind tunnel testing and whether this response does indeed correlate with in-situ observations. Through this paper, these wide ranging subjects are addressed in a manner that demonstrates the importance of continued promotion and expansion of full-scale monitoring efforts and the ways in which these programs can provide true value-added to building owners and managers.

• Korean Journal of Oriental Medicine
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• v.2 no.1
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• pp.40-70
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• 1996

In the literatual study on the cerebral vascular dementia, the results were as follows : 1. Cerebral vascular dementia is so called apoplectic dementia, because it almost occurs after apoplexy, the attack rate has gradually increased by increase of life, so it exert a harmful influence to geriatric diseases. 2. The etiological factors are summarized on deficiency in the heart, kidney, liver(心, 腎, 肝虛), pathogenic wind(豊) pathogenic fire(火) phlegm(痰) and stagnated blood(瘀血) in the oriental medicine, and multiple cerebral infarction, cerebral anemia, decrease of cerebral vascular flow are etiological factors in the occidental medicine. 3. The region of infarction and attack of cerebral vascular dementia have a close connection, and generally the cerebral vascular dementia easily occur in injury of white matter of brain. 4. Symptoms of cerebral vascular dementia are dysphasia, walking disorder, hemiplegia, sensory paralysis, disturbance of memory, judgement, calculation, emotion incontinence, speech impediment, silence or talkative, lower thinking ability and depersonalization, and symptoms are aggravated by stage. 5. Therapeutic herb medicines are Palpungsan(八風散), Baepungsan(排風散), Jinsaanshinhwan(辰砂安神丸), Sabacksan(四白散), Kanghwalyupungsan(姜活愈風散), Woohwangchungshimhwan(牛黃淸心丸), and they are used to dispelling pathogenic wind(祛風), soothe the nerves(安神), dispel pathogenic heat from lung, nourish the blood(淸肺養血).

• Journal of Ocean Engineering and Technology
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• v.38 no.1
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• pp.10-17
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• 2024

This study assessed the potential for crabbing motion in waterjet ships by exclusively employing stern thrusters. The theoretical considerations were validated through practical sea trials on the naval vessel PKG (Patrol Killer Guided missile) equipped with three stern thrusters. The control forces were calculated using the force equilibrium equation. The results showed that the hull exhibited rotations and lateral movements under wind influence. The port tail exhibited a leftward turning tendency due to the wind. This phenomenon arises from the dominance of the rotational force generated by the stern thruster over the lateral force exerted by the hull, making it challenging to maintain force equilibrium. In the sea trial, the hull rotated by 10° and moved 10.8 m laterally, with a longitudinal movement of 0.26 m. Remarkably, the lateral movement surpassed the longitudinal displacement, indicating the success of the trial. The substantial lateral travel distance provided tangible evidence that the crabbing motion of the ship is achievable using only stern thrusters. This study contributes valuable insights into enhancing the maneuverability of waterjet ships, offering practical applications for naval operations and maritime activities.

• Journal of Climate Change Research
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• v.8 no.2
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• pp.81-89
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• 2017

In this study CALPUFF was used to estimate the influence of temperature rise, according to the observation value of temperature rise based RCP scenario, on meteorological elements (wind direction, wind speed, mixing height) and the change of pollutant diffusion. According to the result. applying estimated value of year 2050 temperature rise, the mixing height is increased as per the temperature rise, so the range of atmospheric diffusion is widened. In summer case, by applying temperature rise of $4^{\circ}C$ and comparing with before applying temperature rise, there was change of diffusion range as per the change of temperature between 10 AM to 11 PM. And the range of diffusion was wider than that of before temperature rise. In winter case, by applying estimated value of temperature rise, $2.3^{\circ}C$, diffusion range has been changed between 8 AM to 4 PM, showing different diffusion aspect from summer. Also, according to the result of air pollution level assessment with temperature rise, it was proved that the ratio of area with increasing air pollution level has been getting higher by increase of temperature.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.1
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• pp.286-296
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• 2017

This paper conducted a simulation to research the motion of a vessel, which had the flooding accident in the Bering Sea in 2014, thereby being flooded and un-steerable. As the wind condition was very harsh, the vessel was modeled as 3D including large upper deck structures and the Fujiwara's method was used for an estimation of the effect of wind forces and moments acting on ship. In the case of wave influence, AQWA-Drift that enables considering the effects of drift force and AQWA-Naut that enables considering the effects of green water were mainly used. Basically, loading and flooding condition were equal to the accident condition but half-drained condition was also used to consider drain ability. Furthermore, both 6 DOF and 5 DOF option that Yaw motion is fixed, were utilized to compare the steerable and un-steerable condition. As a result, the author found out that what roll angle triggers green water, how often it happens, and how the vessel moves on the stormy weather condition.