• Wind and Structures
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• v.20 no.6
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• pp.763-791
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• 2015

"Wind and Ports" is a European project that has been carried out since 2009 to handle wind forecast in port areas through an integrated system made up of an extensive in-situ wind monitoring network, the numerical simulation of wind fields, the statistical analysis of wind climate, and algorithms for medium-term (1-3 days) and short term (0.5-2 hours) wind forecasting. The in-situ wind monitoring network, currently made up of 22 ultrasonic anemometers, provides a unique opportunity for detecting high resolution thunderstorm records and studying their dominant characteristics relevant to wind engineering with special concern for wind actions on structures. In such a framework, the wind velocity of thunderstorms is firstly decomposed into the sum of a slowly-varying mean part plus a residual fluctuation dealt with as a non-stationary random process. The fluctuation, in turn, is expressed as the product of its slowly-varying standard deviation by a reduced turbulence component dealt with as a rapidly-varying stationary Gaussian random process with zero mean and unit standard deviation. The extraction of the mean part of the wind velocity is carried out through a moving average filter, and the effect of the moving average period on the statistical properties of the decomposed signals is evaluated. Among other aspects, special attention is given to the thunderstorm duration, the turbulence intensity, the power spectral density and the integral length scale. Some noteworthy wind velocity ratios that play a crucial role in the thunderstorm loading and response of structures are also analyzed.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.1
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• pp.49-54
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• 2016

The wind power plants were installed in many places because of the low climate changing effects since 2000. Generally, the wind power plants located in the seaside and the mountainous area and the heights of the windmills are about 40 m~140 m above the ground level. So the noises emitted from the wind power plants propagate far away compared with other environment noise sources like trains and cars noise. Because of these reasons, the noise emitted from the wind power plant is easy to cause the additional social problems like as noise complaints. Under the situation, the ministry of environment has established the guideline to evaluate the environmental effects for the wind power plant. According to the guideline, the noise of the wind power plant has to meet 55 dB(A) at daytime and 45 dB(A) at night in the residential area, which is regulated in the noise and vibration management law. But, it is difficult to estimate the noise emitted from the wind power plant because of the absence of the prediction model of the wind power plant noise. Therefore, the noise prediction model for wind power plants using the regression analysis method is developed in this study. For the development of the model, the sound pressure levels of the wind power plants in Jeju island are measured and the correlations between the sound pressure levels are analyzed. Finally, the prediction equation of the wind power plant noise using by regression analysis method derived. The prediction equation for the wind power plant noise proposed in this study can be useful to evaluate the environmental effects in any wind power plant development district.

• Journal of Korean Society of Water and Wastewater
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• v.37 no.6
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• pp.447-456
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• 2023

Risk assessment on Jeju Special Self-Governing Province(JSSGP)'s water supply facilities and establishment of adaptation measures for climate crisis factors were implemented. JSSGP's vulnerability to the climate crisis was high in the order of drought, heat wave, heavy rain and strong wind. As a drought adaptation measure, policies of water saving and revenue water ratio improvement were considered. As for the heat wave adaptation measure, the introduction of an advanced water treatment process was suggested in response to the increase of algae cell number which resulting in taste and odor problem. As for heavy rain adaptation measures, the installation and operation of automatic coagulant injection devices for water purification plants that take turbid surface water were proposed. As a measure to adapt to strong winds, stabilization of power supply such as installation of dual power line was proposed in preparation for power outages. It is expected that water facilities will be able to supply high-quality tap water to customers even under extreme climate conditions without interruption through risk assessment for climate crisis factors and active implementation of adaptation measures.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.4
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• pp.605-612
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• 2017

One of the biggest environmental issues that our world has been facing is climate change. In order to cope with such environmental issues, the world is putting a great deal of effort into energy conservation. The building sector, in particular, consumes 36% of the energy consumed worldwide and emits considerable amount of greenhouse gases. Therefore, introduction of renewable energies in the building sector is highly recommended. Renewable energy sources that can be utilized in the building sector include sunlight, solar heat, geothermal heat, fuel cells and wind power. The wind power generation system which converts wind energy into electrical energy has advantages in that wind is an unlimited and pollution-free resource. It is suitable to be connected to existing buildings because many years of operational experience and the enhanced stability of the system have made it possible to downsize the electrical generator. In case of existing buildings, it is necessary to consider the live loads of the buildings to connect the wind power generation system. This paper, through the connection of the wind power generation with existing buildings, promotes reduction of greenhouse gas emissions and energy independence by reducing energy consumption in the building sector. In order to connect the wind power generation system with an exciting building, the live load of the building and the area of the rooftop should be considered. The installable model is selected by comparing the live load of the building and the load of the wind power generation system. The maximum number of the wind turbines that can be installed is obtained by considering the separation distance between the wind turbines within the area of the rooftop. Installations are divided into single installations and multiple installations of two different types of wind turbines. After determining the maximum installable number, the optimal model that can achieve the maximum annual power generation will be selected by comparing the respective total annual amount of the power generation of different models.

• New & Renewable Energy
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• v.17 no.4
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• pp.1-8
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• 2021

To determine the wind turbine class in the offshore of the Korean Peninsula, the reference wind speed for a 50-y return period at the hub height of a wind turbine was estimated using the reanalysis data sets. The most recent reanalysis data, ERA5, showed the highest correlation coefficient (R) of 0.82 with the wind speed measured by the Southwest offshore meteorological tower. However, most of the reanaysis data sets except CFSR underestimated the annual maximum wind speed. The gust factor of converting the 1 h-average into the 10 min-average wind speed was 1.03, which is the same as the WMO reference, using several meteorological towers and lidar measurements. Because the period, frequency, and path of typhoons invading the Korean Peninsula has been changing owing to the climate effect, significant differences occurred in the estimation of the extreme wind speed. Depending on the past data period and length, the extreme wind speed differed by more than 30% and the extreme wind speed decreased as the data period became longer. Finally, a reference wind speed map around the Korean Peninsula was drawn using the data of the last 10 years at the general hub-height of 100 m above the sea level.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.6
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• pp.738-749
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• 2016

To understand the characteristics of the spatio-temporal distribution of phytoplankton after barrage construction in the Nakdong River Estuary, this study investigated relevant environmental parameters and phytoplankton status based on bi-monthly samples collected from the Nakdong River Estuary itself from February 2013 to December 2015. Environmental parameters did not differ significantly across these years but did vary between zones and seasons. The results suggested that the upper zone was dominated by fresh-water diatoms, green algae, and blue-green algae, whereas the lower zone was mostly dominated by dinoflagellates. The presence of Stephanodiscus spp., Asterionellopsis formosa, and Microcystis spp. in the upper zone was related to the inflow of freshwater discharge by artificial control of dyke gates. The dominant phytoplankton species in this zone were dependent on temperature, wind speed, DIP, and DIN, while those in the lower zone were mostly dependent on nutrients and wind speed. In addition, at the lower zone, there were negative correlations between Prorocentrum donghaiense, DIN, and wind speed, with its abundance being higher during the summer than other seasons. Analysis of temporal variations did not indicate any significant differences in the upper zone but did reveal variations among seasons at the lower zone. Except in 2014, the lower zone could be divided into periods dominated by diatoms (October-April) and dinoflagellates (June-August). These results suggest that the characteristics of the phytoplankton community were influenced by changes in the inflow of freshwater species and nutrients given the difference in the range affected by freshwater discharge.

• New & Renewable Energy
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• v.20 no.2
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• pp.44-54
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• 2024

The objective of this study was to contribute to domestic offshore wind farms by reasonably predicting the expected completion time and installed power generation capacity of offshore wind projects in South Korea. Offshore wind power is drastically regarded as a core tool for clean energy transition and industrial decarbonization in the fight against the climate crisis globally. Especially in South Korea offshore wind power is the main tool in partaking in RE100 and K-RE100, and the Korean government aims to install 14.9 GW of offshore wind farms by 2030. However, this seems to have been significantly delayed due to the complex process of obtaining permits for offshore wind power in Korea. Thus, a reasonable prediction of power generation and a timeline for the final construction are imperative. To establish the delay time for permit licenses, classified location factors were included into site analysis. These factors comprised reviews of transmission and military operability, environmental impact assessment, maritime traffic safety examination, wind resource assessment and an analysis of current offshore wind projects. According to the analysis, the majority of offshore wind projects currently being developed in Korea are predicted to be delayed by 3-5 years as they are among the criteria included in key discussion points for obtaining permits. The cumulative installed power capacity and annual power generation after construction are expected to be 37 GW and 97 TWh respectively.

• Proceedings of the Korean Quaternary Association Conference
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• 2004.06a
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• pp.24-25
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• 2004

It is well known that there is an inverse relationship between the strength of Indian summer monsoon Rainfall (ISMR) and extent of Eurasian snow cover/depth in the preceding season. Tibetan snow cover/depth also affects the Asian monsoon rainy season largely. The positive correlation between Tibetan sensible heat flux and southeast Asian rainfall suggest an inverse relationship between Tibetan snow cover and southeast Asian rainfall. Developments in Regional Climate Models suggest that the effect of Tibetan snow on the ISMR can be well studied by Limited Area Models (LAMs). LAMs are used for regional climate studies and operational weather forecast of several hours to 3 days in future. The Eta model developed by the National Center for Environmental Prediction (NCEP), the Fifth-Generation NCAR/Penn State Mesoscale Model (MM5) and Regional Climate Model (RegCM) have been used for weather prediction as well as for the study of present-day climate and variability over different parts of the world. Regional Climate Model (RegCM3) has been widely . used for various mesoscale studies. However, it has not been tested to study the characteristics of circulation features and associated rainfall over India so far. In the present study, Regional Climate Model (RegCM-3) has been integrated from 1 st April to 30th September for the years 1993-1996 and monthly mean monsoon circulation features and rainfall simulated by the model at 55km resolution have been studied for the Indian summer monsoon season. Characteristics of wind at 850hPa and 200hPa, temperature at 500hPa, surface pressure and rainfall simulated by the model have been examined for two convective schemes such as Kuo and Grell with Arakawa-Schubert as the closure scheme, Model simulated monsoon circulation features have been compared with those of NCEP/NCAR reanalyzed fields and the rainfall with those of India Meteorological Department (IMD) observational rainfall datasets, Comparisons of wind and temperature fields show that Grell scheme is closer to the NCEP/NCAR reanalysis, The influence of Tibetan snowdepth in spring season on the summer monsoon circulation features and subsequent rainfall over India have been examined. For such sensitivity experiment, NIMBUS-7 SMMR snowdepth data have been used as a boundary condition in the RegCM3, Model simulation indicates that ISMR is reduced by 30% when 10cm of snow has been introduced over Tibetan region in the month of previous April. The existence of Tibetan snow in RegCM3 also indicates weak lower level monsoon westerlies and upper level easterlies.

• Journal of the Korean Society of Industry Convergence
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• v.9 no.1
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• pp.29-35
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• 2006

The population of Daegu, the third biggest city in Korea, is two point six million. Daegu is known as a basin or a city where it is not only too hot in summer but also too cold in winter. Recently with redevelopment apartment house boom, a 40-story or more apartment complexes are under construction near Shin-cheon and Dondaegu-ro, the south-north axis of Daegu. It is necessary to raise several points about blocking a road of the wind by high-rise apartment buildings and apartment complexes. As a kind of the green policy, Daegu enlarge the distance between apartment building by reconstructing low-rise apartment into high-rise and impose a duty of a green space on the ground by making a parking zone into an underground. Through this process, apartment complexes changed from a '一'shape to a '口'shape. It increases heat island phenomenon of a city by blocking a road of the wind that comes from Shin-cheon and Dondaegu-ro. To circulate the polluted air of Daegu basin, we need local wind. There are four effective measures. 1) Throw three greens into one in the center of the road at the north side in the same way of the south side of Dongdaegu-ro, 2) reflect the information of roads of the wind including heights, spaces and directions of buildings, 3) steer clear of a high-rise buildings and development apartment house constructions, and 4)select a city for benchmarking to be the environmental capital.

• The Transactions of the Korean Institute of Power Electronics
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• v.22 no.4
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• pp.330-335
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• 2017

Increased fossil fuel consumption causes global warming, environmental pollution, and abnormal climate change. Wind-generated power installation is proposed to solve this problem. Recently, the wind power plant construction case encourages the installation of the energy storage system (ESS) to improve the intermittency of wind power. The maximized ESS operation profits connected to wind power are not generated in the simplest operation pattern of charging at night and discharging at day. The battery charging efficiency improvement should be considered to get more profits. Thus, there is a possibility of increasing ESS operation profits by analyzing the battery AC and DC charging/discharging efficiency and the yearly average sealed maintenance free (SMP) in hours. In this paper, the battery impedance characteristic, AC and DC charging/discharging efficiency, and the yearly average SMP are analyzed. The operation scenario to improve the ESS battery charging efficiency connected to wind power is proposed and verified via simulation.