• Journal of Environmental Impact Assessment
• /
• v.21 no.1
• /
• pp.1-13
• /
• 2012

We diagnosed on status and problems of environmental assessment regarding development of offshore wind power, and also on reasonable core assessment items. Most of the coastal wind power are located on the western coastline of Korea and Jeju Island. In the selections of the site for the offshore wind farms, a previous investigations should be conducted with regard to distances from the land, stabilities from external forces (tide, wave, etc.) and topographical changes, and characteristics of the surroundings (distributions of protected area, fishing ground, artificial seagrasses, and shipping traffic). It is needed to assess dispersion of suspended solids, changes of the sea bottom, and impacts on fisheries resources and fishing activities under construction of offshore wind power. Furthermore, the responses of marine organisms to noise and vibration, impacts by electromagnetic fields, impacts on sea birds, hindrances to sea lane routes, and damaged scenery and marine protection areas are thoroughly assessed during operation processes. The consultation criteria in case of development of offshore wind farm is adjusted by focusing marine environmental impact assessment.

• Wind and Structures
• /
• v.16 no.6
• /
• pp.579-601
• /
• 2013

Interference effects are of considerable concern for group hyperboloidal cooling towers, but evaluation methods and results are different from each other because of the insufficient understanding on the structure behavior. Therefore, the mechanical performance of hyperboloidal cooling tower shell under wind loads was illustrated according to some basic properties drawn from horizontal rings and cantilever beams. The hyperboloidal cooling tower shell can be regarded as the coupling of horizontal rings and meridian cantilever beams, and this perception is beneficial for understanding the mechanical performance under wind loads. Afterwards, the mean external latitude wind pressure distribution, CP(${\theta}$), was artificially adjusted to pursue the relationship between different CP(${\theta}$) and wind-induced responses. It was found that the maximum responses in hyperboloidal cooling tower shell are primarily dominated by the non-uniformity of CP(${\theta}$) but not the local pressure amplitude CP or overall resistance/drag coefficient CD. In all the internal forces, the maximum amplitude of meridian axial tension shows remarkable sensitivity to the variation of CP(${\theta}$) and it's also the controlling force in structure design, so it was selected as an indicator to evaluate the influence of CP(${\theta}$) on responses. Based on its sensitivity to different adjustment parameters of CP(${\theta}$), an comprehensive response influence factor, RIF, was deduced to assess the meridian axial tension for arbitrary CP(${\theta}$).

• Journal of Korean Medical classics
• /
• v.19 no.4
• /
• pp.241-256
• /
• 2006

Aversion to wind is a feeling of cold when exposed to wind; aversion to cold is a feeling of cold. The distinction between aversion to wind and aversion to cold is ambiguous because in greater yang disease the two terms seem to be used indiscriminately. It is, however, worth noting that "aversion to wind" does not occur in the lines presenting disease of the three yin. In this text, we render as "heat effusion" rather than "fever," since the Chinese term is somewhat wider in meaning than familiar English term, Heat effusion is associated with many conditions and occurs both in externally contracted disease and miscellaneous disease (雜病), disease due to causes other than external evils). In externally contracted disease of the three yang channels, heat effusion is a manifestation of the struggle between right qi and evil qi; it does not necessarily indicate the presence of evil heat. In diseases of the three yin, right qi is not strong enough to counter evil qi; hence heat effusion is absent, and instead only aversion to cold is present. Sweating occurs in a variety of patterns. A distinction is made between spontaneous and night sweating(自汗). Spontaneous sweating is so called because it occurs spontaneously without exertion. it has numerous causes. Night sweating(盜汗) is sweating during sleep that ceases on awakening.

• Journal of the Society of Naval Architects of Korea
• /
• v.36 no.1
• /
• pp.1-14
• /
• 1999

The simulation results of a small racing boat racing in steady wind and encountering waves are investigated by Nakato & Ha. The simulation of the race running is realized by referring the measured data of boats and the motions are described by a set of equations of motion in six degree of freedom as generals used in the aerodynamics. In this report, Nakato & Ha's motion equations are modified by equipping the flaps to generate the lift. The flaps of the racing boat could restrain considerably the boat from capsizing caused by superposed external disturbances, wind and encountering waves.

• Wind and Structures
• /
• v.24 no.1
• /
• pp.79-93
• /
• 2017

Wind-induced fluctuating internal pressures in a building with a dominant opening can be described by a second-order non-linear differential equation. However, the accuracy and efficiency of the governing equation in predicting internal pressure fluctuations depend upon two ill-defined parameters: inertial coefficient $C_I$ and loss coefficient $C_L$, since $C_I$ determines the un-damped oscillation frequency of an air slug at the opening, while $C_L$ controls the decay ratio of the fluctuating internal pressure. This study particularly focused on the value of loss coefficient and its influence factors including: opening configuration and location, internal volumes, as well as wind speed and approaching flow turbulence. A simplified formula was presented to predict loss coefficient, therefore an approximate relationship between the standard deviation of internal and external pressures can be estimated using Vickery's approach. The study shows that the loss coefficient governs the peak response of the internal pressure spectrum which, in turn, will directly influence the standard deviation of the fluctuating internal pressure. The approaching flow characteristic and opening location have a remarkable effect on the parameter $C_L$.

• Journal of Mechanical Science and Technology
• /
• v.17 no.5
• /
• pp.776-783
• /
• 2003

A low speed wind tunnel test was conducted for full-scale model of an unmanned aerial vehicle (UAV) in Korea Aerospace Research Institute (KARI) Low Speed Wind Tunnel(LSWT). The purpose of the presented paper is to illustrate the general aerodynamic and performance characteristics of the UAV that was designed and fabricated in KARI. Since the testing conditions were represented minor portions of the load-range of the external balance system, the repeatability tests were performed at various model configurations to confirm the reliability of measurements. Variations of drag-polar by adding model components such as tails, landing gear and test boom are shown, and longitudinal and lateral aerodynamic characteristics after changing control surfaces such as aileron, flap, elevator and rudder are also presented. To explore aerodynamic characteristics of an UAV with model components build-up and control surface deflections, lift curve slope, pitching moment variation with lift coefficients and drag-polar are examined. The discussed results might be useful to understand the general aerodynamic characteristics and drag pattern for the given UAV configuration.

• Journal of Urban Science
• /
• v.8 no.1
• /
• pp.25-31
• /
• 2019

Infiltration affects indoor environmental and air quality and energy consumptions in buildings. Especially, airflow and the infiltration are more remarkable in high-rise buildings due to the air-driving forces (stack and wind effects). Thus, it is important to understand infiltration distributions in high-rise residential buildings. In this study, the weather-driven infiltration is characterized from the viewpoint of interactions between external wind and stack effect in high-rise residential buildings. To calculate accurately the annual infiltration distributions, this study also suggests an airflow and thermal simulation method with a two-step calibration of air-leakage data. The simulated results show (1) how the interaction between stack and wind effects induce infiltration types (outdoor and interzone air infiltration) and (2) how much the interzone air infiltration (being ignored in previous studies) occurs due to the stack effect, as well as the outdoor air infiltration rates.

• Journal of Wind Energy
• /
• v.15 no.2
• /
• pp.37-44
• /
• 2024

In this study, a tensile test and FE analysis were conducted on a bolt-connected L-shaped flange to evaluate its behavior and load resistance. A total of five specimens were manufactured using the inner and outer distances and bolt diameters of the L-type flange as experimental variables. As a result of the tensile test of the L-shaped flange, as the internal and external length ratio (b/a) increased, the maximum load decreased and the maximum displacement increased. As the diameter (d) of the bolt increased, the maximum load and the deformation of the wall increased. The shapes of the destruction specimens showed two forms of destruction: one due to the fall of the nut and the surrender of the bolt as the thread of the bolt and nut was worn out, followed by the surrender of the wall. As a result of FE analysis, it was found that elasto-plastic model (EPM) analysis similarly tracks the behavior of the tensile test results.

• Wind and Structures
• /
• v.16 no.1
• /
• pp.1-23
• /
• 2013

The wind-induced transient response of internal pressure following the creation of a sudden dominant opening during the occurrence of high external pressure, in low-rise residential and industrial buildings was numerically investigated. The values of the ill-defined parameters namely the flow contraction coefficient, loss coefficient and the effective slug length were calibrated by matching the analytical response with the computational fluid dynamics predictions. The effect of a sudden i.e., "instantaneously created" windward opening in the Texas Technical University (TTU) test building envelope was studied for two different envelope flexibility-leakage combinations namely: (1) a quasi-statically flexible and non-porous envelope and (2) a quasi-statically flexible and porous envelope. The responses forced by creating the openings at different time leads/lags with respect to the occurrence of the peak external pressure showed that for cases where the openings are created in close temporal proximity to the peak pressure, the transient overshoot values of internal pressure could be higher than the peak values of internal pressure in the pre-sequent or subsequent resonant response. In addition, the influence of time taken for opening creation on the level of overshoot was also investigated for the TTU building for the two different envelope characteristics. Non-dimensional overshoot factors are presented for a variety of cavity volume-opening area combinations for (1) buildings with rigid/quasi-statically flexible non-porous envelope, and (2) buildings with rigid/quasi-statically flexible and porous envelope (representing most low rise residential and industrial buildings). While the factors appear slightly on the high side due to conservative assumptions made in the analysis, a careful consideration regarding the implication of the timing and magnitude of such overshoots during strong gusts, in relation to the steady state internal pressure response in cyclonic regions, is warranted.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.31 no.4
• /
• pp.201-212
• /
• 2017

This study draws pattern differentiations of headache disorders on the ground of modern clinical applications and Korean medical literature. Categorization and symptoms of headache disorders are based on International Classification of Headache Disorders 3rd edition(beta version). And clinical papers are searched in China Academic Journals(CAJ) of China National Knowledge Infrastructure(CNKI). In the aspect of eight principle pattern identification, primary headache occurs due to lots of yang qi and has more inner pattern rather than exterior pattern, heat pattern rather than cold pattern, excess pattern rather than deficiency pattern. And primary headache is related with liver in the aspect of visceral pattern identification and blood stasis, wind and phlegm are relevant mechanisms. Migraine without aura is associated with ascendant hyperactivity of liver yang, phlegm turbidity, sunken spleen qi, wind-heat, blood deficiency or yin deficiency. Migraine with aura is mainly related with wind and it's major mechanisms are ascendant hyperactivity of liver yang, liver fire, yin deficiency of liver and kidney, blood deficiency or liver depression and qi stagnation. High repetition rate of tension-type headache can be identified as heat pattern or excess pattern. And trigeminal autonomic cephalalgias can also be accepted as heat pattern or excess pattern when the occurrence frequency is high and is relevant to combined pattern with excess pattern of external contraction and deficiency pattern of internal damage based on facial symptoms by external contraction and nervous and anxious status by liver deficiency. This study can be expected to be Korean medical basis of clinical practice guidelines on headache by proposing pattern identifications corresponding to the western classifications of headache disorders.