• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.267-268
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• 2012

To evaluate the incoming salt quantitatively which is the reason of salt attack is a very important aspect to calculate the durability life of the structure. Incoming salt is influenced by various weather changes during the transmission and consequently, the changes of incoming salt quantity occur. Therefore, the study to analyze incoming salt quantity was executed which are changed by the weather environments (occurrence frequency of wind direction / wind speed); study results showed that influences to the changes of incoming salt quantity are bigger than those of wind speed, compared with the frequencies.

• Journal of radiological science and technology
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• v.30 no.3
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• pp.219-225
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• 2007

This study was performed for the purpose of providing basic data of the pelvic disorders through survey of the frequency of management of occurrence by major risk factor. Female pelvic mass was detected using sonography, and necessary data were collected from 604 female visitors to a obstetrics and gynecology hospital located at S-si. Female pelvic mass was uterus mass, ovarian mass, cervical cyst, endometrial disease. For the analysis, such variables as age, weight and frequency of pregnancy were chosen as risk factors. Results of the analysis and conclusions are as follows ; 1) The frequency of occurrence of the female pelvic mass is highest, as 38.9% of the component ratio, in the age of 35 to 54. It maintains high level of 35.8% even in the age of 55 and above. 2) The frequency of occurrence of the female pelvic mass increases in proportion as the weight and frequency of pregnancy increase. 3) The size of the uterus tumor has no statistical relationship with the risk factors, age, weight and frequency of pregnancy.

• Particle and aerosol research
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• v.15 no.2
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• pp.45-56
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• 2019

The public's concern on ambient $PM_{2.5}$ has been increasing in Korea. We have estimated (1) the annual and monthly mean $PM_{2.5}$ concentrations, (2) the frequency by the $PM_{2.5}$ concentration interval, and (3) the high concentration occurrence duration time between 2015 and 2018 at 16 administration regions. We found that there have been differences in all three above parameters' trends among the studied 16 regions in Korea. Still, Jeonbuk showed the highest rank in all three parameters' trends. In Jeonbuk, the average $PM_{2.5}$ concentration and the sum of the frequency fraction when the $PM_{2.5}$ concentration being over $75{\mu}g/m^3$ between 2016 and 2018 was $28.4{\mu}g/m^3$ and 9.0%, respectively. And the days when the $PM_{2.5}$ concentration is over $50{\mu}g/m^3$ between 2015 and 2018 were 149. Chungbuk was the only region with the increasing trend of $PM_{2.5}$ concentration between 2016 and 2018. And in Seoul and Gyeonggi, the average $PM_{2.5}$ concentrations decreased whereas the high concentration frequency fraction increased between 2016 and 2018. Also, it is found that there have been differences in the trends of the frequency by the $PM_{2.5}$ concentration interval and the high concentration occurrence duration time between $PM_{10}$ and $PM_{2.5}$.

• The Korean Journal of Mycology
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• v.32 no.2
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• pp.71-78
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• 2004

This study was conducted to investigate the diversity and occurrence frequency of ectomycorrhizal fruit bodies by planting sites from June 2000 to October 2001. A total of 3 classes 3 subclasses 8 orders 22 families 41 genera and 72 species (including two varieties) including saprophytic and ectomycorrhizal fungi was investigated. The mushrooms are classified into 9 families 21 genera and 48 species in Agaricales, 5 families 11 genera and 13 species in Aphllophorales, 3 families 3 genera and 4 species in Heterobasidiomycetes and 5 families 6 genus and 7 species in Gasteromycetdae. A total of 7 families 11 genera 30 species (2,451 ea.) of ectomycorrhizal mushroom was investigated. The occurrence frequency of mushrooms was 1,225, 179 and 130 times for Laccaria vinaceoavellanea, Amanita longistriata and Laccaria amethystea, respectively. The mushroom occurrence of ectomycorrhizal fungi was closely related to climatic conditions such as high air temperature, relative humidity and lots of rainfall from July to August. Diversity and distribution of ectomycorrhizal fungi by plots were very different because of variable local environments and different host plants in experimental plots. Laccaria vinaceoavellanea has showed very low host range of plant specificity because of mushroom occurrence in only Quercus sp. and Amanita longistriata, Russula bella and Inocybe sp. have showed wide host range of plant specificity because of mushroom occurrence in coniferous and broadleaved trees. The environment which has a favorable influence of mushroom occurrence was soil pH, organic matter and T/N ratio of soil enviromental and humidity of climatic environment.

• Environmental Engineering Research
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• v.14 no.2
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• pp.88-94
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• 2009

In this study an attempt has been made to predict the annual foggy days over Gyeongsangbuk-do of Korea, using the regional mesoscale model (MM5). The annual meteorological conditions are simulated, and the annual and seasonal foggy days are predicted from the simulated results based on the seasonal and spatial information of the observed meteorological characteristics for fog occurrence such as wind speed, relative humidity, and temperature. Most of observed inland fog over Gyeongsangbuk-do occurs in autumn under the meteorological conditions such as a cairn, a high temperature range (above $10^{\circ}C$), and a high relative humidity (above 85%). The predicted results show the various foggy days, about 10${\sim}$60 days, depending on the season and the site locations. The predicted annual foggy days at inland sites are about 30${\sim}$60 days, but at coastal sites, about 10${\sim}$20 days. Also, a higher frequency of fog occurrence at inland sites is shown in autumn (about 60% of the annual foggy days). Otherwise, a higher frequency of fog occurrence at coastal sites is shown in summer (about 60% of the annual foggy days), unlike the inland. These annual foggy days and their seasonal variations agree reasonably well with the observed values. It can be concluded that it is possible to predict the occurrence of annual or seasonal foggy days by MM5.

• Journal of Korean Society of Steel Construction
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• v.26 no.5
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• pp.375-383
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• 2014

In Seoul, total 166 places of foot-bridges were constructed but a study on correlation between resonance occurrence status by gait vibration and natural frequency by each span and that between span based on structural system and natural frequency is very unsatisfactory in reality. Consequently in this study, time series wave form, power spectrum and natural frequency were analyzed based on resonance occurrence by targeting 65 places of foot-bridges being constructed in Seoul through convenient and simple portable vibration meter.

• The Bulletin of The Korean Astronomical Society
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• v.30 no.2
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• pp.78.1-78.1
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• 2005

• Journal of the Korea Society of Computer and Information
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• v.12 no.5
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• pp.235-241
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• 2007

AThis research is rather on the crime occurrence of target area's space scope than on the approach to the cause of specific area's crime occurrence from the perspective of the environmental criminology emphasizing the crime prevention. By observing the composition of crime distribution, it is intended to search the strategies of crime prevention actually corresponded to the crime problems. For this, after segmenting the city into six sectors, targeting city crimes in Gwangju metropolitan city, in 2004, the basic materials about the crime frequency are analyzed through dividing the types on the base of the present state of crime occurrence, the types of crime, the locations of crime occurrence, the purposes of buildings, the types of intruders, the forms of intrusions. As a result of research. it is suggested that the activation method of community police activities is necessary for the prevention of community crime prevention.

• Mycobiology
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• v.28 no.4
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• pp.193-196
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• 2000

Thirty-eight species in addition to 2 varieties (3 unidentified) of zoosporic organisms belonging to 14 genera of Oomycetes and 3 genera of Chytridiomycetes were recovered from 50 soil samples randomly collected from different localities in the western region of Saudi Arabia. Allomyces and Dictyuchus have the highest frequency of occurrence while Achlya, Aqualinderella, Saproleginia and Phytophthora were of moderate occurrence, The remaining genera were less frequent. Seven species and two varieties were new records to Saudi Arabia, which are Achlya oblongata, Allomyces javancius var. allomorphus, Aphanomyces stellatus, Blastoccladia gracile, Dictyuchus magnusii, Olpidiopsis Saproleginia var. levis, Olpidium species, Phytophthora megasperma, and Saproleginia turfosa. Water and organic matter contents of soil samples are considered as major factors influencing the prevalence and occurrence of zoosporic organisms.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.166-166
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• 2023

Compound hazards (CHs) are two or more extreme climate events combined which occur simultaneously in the same region at the same time. Compared to individual hazards, the combination of hazards that cause CHs can result in greater economic losses and deaths. While several extreme climate events have been recorded across Asia for the past decades, many studies have only focused on a single hazard. In this study, we assess the spatiotemporal pattern of dry compound hazards which includes drought, heatwave, fire and wind across Asia for the last 42 years (1980-2021) using the historical data from ERA5 Reanalysis dataset. We utilize a daily spatial data of each climate event to assess the occurrence of such compound hazards on a daily basis. Heatwave, fire and wind hazard occurrences are analyzed using daily percentile-based thresholds while a pre-defined threshold for SPI is applied for drought occurrence. Then, the occurrence of each type of compound hazard is taken from overlapping the map of daily occurrences of a single hazard. Lastly, a multivariate assessment are conducted to quantify the occurrence frequency, hotspots and trends of each type of compound hazard across Asia. By conducting a multivariate analysis of the occurrence of these compound hazards, we identify the relationships and interactions in dry compound hazards including droughts, heatwaves, fires, and winds, ultimately leading to better-informed decisions and strategies in the natural risk management.