• Weed & Turfgrass Science
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• v.2 no.2
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• pp.170-175
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• 2013

Korea is carrying out weed quarantine by plant quarantine regulations including heat-treatment method to prevent the influx of exotic weeds. In order to confirm suitability for current heat-treatment criteria and find field-applicable methods which can completely devitalize quarantine weed seeds, the conditions for heat-treatment with/without 40% relative humidity were studied with 9 species among quarantine weed seeds and one weed species similar to quarantine weed. Dry heat-treatments had been tested under various temperatures and time conditions. All seeds were dead at the conditions of $95^{\circ}C$ for 48 hours, $100^{\circ}C$ for 36 hours, $110^{\circ}C$ for 24 hours, $121^{\circ}C$ for 4 hours and $130^{\circ}C$ for 30 minutes. Heat-treatments at 40% relative humidity resulted in complete seed death at the conditions of $85^{\circ}C$ for 36 hours and $90^{\circ}C$ for 16 hours. The above results show that current heat-treatment criteria are not suitable for several quarantine weeds and these conditions could be applied as a quarantine method to prevent the influx of quarantine weeds along with agricultural imports. More specific conditions for heat tolerant species such as Picris echioides and heat susceptible species such as Cuscuta spp. are necessary and will improve plant quarantine process in devitalizing quarantine weed seeds with different heat tolerances.

• Journal of Advanced Navigation Technology
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• v.17 no.5
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• pp.516-523
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• 2013

In this paper, The path loss model of Air Traffic Control(ATC) telecommunication radio channel has been studied at the Incheon International Airport(IIA) with the terminal with two antlers. We measured two frequencies among VHF/UHF channel bands. The transmitting site radiated the Continuous Wave(CW). The propagation measurement was taken using the moving vehicle equipped with receiver and antenna. The transmitting power, frequency and antenna height are the same as the current operating condition. The path loss exponent and intercept parameters were extracted by the basic path loss model and hata model. The path loss exponents at passager terminal areas were 3.32 and 3.10 respectively in 128.2 MHz and 269.1 MHz. The deviation of prediction error is 9.69 and 9.65. The new path loss equation at the terminal area was also developed using the derived path loss parameters. The new path loss was compared with other models. This result will be helpful for the ATC site selection and service quality evaluation.

• Journal of the Korean GEO-environmental Society
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• v.20 no.2
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• pp.19-28
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• 2019

Grounds of the western coast of the Korean Peninsular are mostly composed of soft and cohesive soils, and it is necessary to carry out soil improvement before construction. The CGS (Compaction Grouting System) method has been commonly applied for the purpose of not only improving soft ground but also serving as the pile foundation of a bridge. In this paper, the CGS method was applied to the Incheon International Airport facility site, which consists of reclaimed landfill and soft clay soil, so as to evaluate the applicability of this soil improvement method to soft clay ground formations. Futhermore, results of construction were intensively studied along with a series of field experiments and theoretical consideration. The cone penetration tests were performed to assess the ground improvement effect of the CGS method. Consequently, the application of CGS method led to an increase in soil strength enough to be used as the pile foundation to support the bridge at the site. In addition, the size of the upper grout-bulb was estimated by adopting the cavity expansion theory and compared with that of actual grout bulb exhumed in the field. Therefore, it is proved that the cavity expansion theory can be utilized to predict and evaluate the improvement of soft ground.

• Journal of Korea Water Resources Association
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• v.52 no.8
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• pp.545-554
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• 2019

The most drought assessments are based on a drought index, which depends on univariate variables such as precipitation and soil moisture. However, there is a limitation in representing the drought conditions with single variables due to their complexity. It has been acknowledged that a multivariate drought index can more effectively describe the complex drought state. In this context, this study propose a Copula-based drought index that can jointly consider precipitation and soil moisture. Unlike precipitation data, long-term soil moisture data is not readily available so that this study utilized a Gaussian Mixture Non-Homogeneous Hidden Markov chain Model (GM-NHMM) model to simulate the soil moisture using the observed precipitation and temperature ranging from 1973 to 2014. The GM-NHMM model showed a better performance in terms of reproducing key statistics of soil moisture, compared to a multiple regression model. Finally, a bivariate frequency analysis was performed for the drought duration and severity, and it was confirmed that the recent droughts over Jeollabuk-do in 2015 have a 20-year return period.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.12
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• pp.899-907
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• 2022

According to the Unmanned aircraft system Traffic Management (UTM), drones are permitted to fly up to 150m above ground, which is located in the atmospheric boundary layer where there is considerable wind fluctuation due to turbulence. Although it is difficult to predict when turbulence will occur drone aviation safety could be enhanced by having a better understanding of the characteristics of vertical profile of wind in the flight area. We used wind lidar (WIndMast 350M) to observe vertical profiles of wind at the test site for aviation meteorological observation equipment located near Incheon International Airport in July and September, 2022. In this study, we utilized the observed wind profile data to propose a technique for obtaining information that could help improve the drone aviation safety. The Fourier transform analysis is used to evaluate the temporal characteristics of the horizontal wind speed at various vertical levels up to 350m. We also examined the relative contribution of the variance of wind having scales of less than an hour, a crucial scale for drone flight, to the variance of wind having all scales at each vertical altitude for days with and without precipitation.

• Journal of Internet Computing and Services
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• v.14 no.5
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• pp.69-76
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• 2013

The incidence of globally infectious and pathogenic diseases such as H1N1 (swine flu) and Avian Influenza (AI) has recently increased. An infectious disease is a pathogen-caused disease, which can be passed from the infected person to the susceptible host. Pathogens of infectious diseases, which are bacillus, spirochaeta, rickettsia, virus, fungus, and parasite, etc., cause various symptoms such as respiratory disease, gastrointestinal disease, liver disease, and acute febrile illness. They can be spread through various means such as food, water, insect, breathing and contact with other persons. Recently, most countries around the world use a mathematical model to predict and prepare for the spread of infectious diseases. In a modern society, however, infectious diseases are spread in a fast and complicated manner because of rapid development of transportation (both ground and underground). Therefore, we do not have enough time to predict the fast spreading and complicated infectious diseases. Therefore, new system, which can prevent the spread of infectious diseases by predicting its pathway, needs to be developed. In this study, to solve this kind of problem, an integrated monitoring system, which can track and predict the pathway of infectious diseases for its realtime monitoring and control, is developed. This system is implemented based on the conventional mathematical model called by 'Susceptible-Infectious-Recovered (SIR) Model.' The proposed model has characteristics that both inter- and intra-city modes of transportation to express interpersonal contact (i.e., migration flow) are considered. They include the means of transportation such as bus, train, car and airplane. Also, modified real data according to the geographical characteristics of Korea are employed to reflect realistic circumstances of possible disease spreading in Korea. We can predict where and when vaccination needs to be performed by parameters control in this model. The simulation includes several assumptions and scenarios. Using the data of Statistics Korea, five major cities, which are assumed to have the most population migration have been chosen; Seoul, Incheon (Incheon International Airport), Gangneung, Pyeongchang and Wonju. It was assumed that the cities were connected in one network, and infectious disease was spread through denoted transportation methods only. In terms of traffic volume, daily traffic volume was obtained from Korean Statistical Information Service (KOSIS). In addition, the population of each city was acquired from Statistics Korea. Moreover, data on H1N1 (swine flu) were provided by Korea Centers for Disease Control and Prevention, and air transport statistics were obtained from Aeronautical Information Portal System. As mentioned above, daily traffic volume, population statistics, H1N1 (swine flu) and air transport statistics data have been adjusted in consideration of the current conditions in Korea and several realistic assumptions and scenarios. Three scenarios (occurrence of H1N1 in Incheon International Airport, not-vaccinated in all cities and vaccinated in Seoul and Pyeongchang respectively) were simulated, and the number of days taken for the number of the infected to reach its peak and proportion of Infectious (I) were compared. According to the simulation, the number of days was the fastest in Seoul with 37 days and the slowest in Pyeongchang with 43 days when vaccination was not considered. In terms of the proportion of I, Seoul was the highest while Pyeongchang was the lowest. When they were vaccinated in Seoul, the number of days taken for the number of the infected to reach at its peak was the fastest in Seoul with 37 days and the slowest in Pyeongchang with 43 days. In terms of the proportion of I, Gangneung was the highest while Pyeongchang was the lowest. When they were vaccinated in Pyeongchang, the number of days was the fastest in Seoul with 37 days and the slowest in Pyeongchang with 43 days. In terms of the proportion of I, Gangneung was the highest while Pyeongchang was the lowest. Based on the results above, it has been confirmed that H1N1, upon the first occurrence, is proportionally spread by the traffic volume in each city. Because the infection pathway is different by the traffic volume in each city, therefore, it is possible to come up with a preventive measurement against infectious disease by tracking and predicting its pathway through the analysis of traffic volume.

• Korean Journal of Heritage: History & Science
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• v.41 no.2
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• pp.79-97
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• 2008

Four Wangs' landscape style (四王山水畵風), which had appeared in Beijing in the early 18th century, widely spread to Korea and Japan in the 19th century and became a significant basis for developing new painting styles in both countries. It was first introduced to Korea by Shin Wi (申緯) and Kim Jeong-hee (金正喜) who associated with literary men of the Qing Dynasty. Being influenced by them directly or indirectly, Shin Myeong-yeon (申命淵), Yi Han-cheol (李漢喆), Yu Suk (劉淑), Changv Seung-eop (張承業), An Choog-sik (安中植), and Jo Seok-jin (趙錫晋) attempted to adapt Four Wangs' landscape style and it later became a main Stream painting style of the Korean painting circles. Based on Four Wangs' landscape style, their landscape paintings had something in common in that they captured natural features from a short distance using the Down-Up prospective and placed guardian mountains across mountain streams by making a tall tree in the right or left bottom of the canvas as the starting point. However, recently unveiled court painter An Geon-yeong (1841~1876)'s the Landscape Screen is remarkable in that it is based on Four Wangs' style, which was in fashion in the late 19th century, but shows different aspects from other Four Wangs' style paintings in terms of feature capturing, brush stroke and colors. While most of An Geon-yeong's existing paintings are small ones, this folding screen is a big piece consisting of six-fold landscape paintings. In particular, it shows new aspects by creating a serene and calm atmosphere through the description of various landscape scenes with thin brush strokes using glossy ink, by showing a macroscopic view in some paintings through feature capture using a birds-eye view method, and by giving life to the canvas through smoke and clouds. This painting style is considered to be linked with those of Wang Xue-hao (王學浩, 1754~1832), Tang Yifen (湯貽汾, 1778~1853) and Dai Xi (戴熙, 1801~1860), based on Four Wangs' style in the early 19th century's Jiangnan Circle (江南 畵壇), who tried to express the energy and vitality of real landscapes by going around China's well-known mountains and complementing painting styles with drawing from nature. Therefore, An Geon-yeong's six-fold Landscape Screen is very significant as a rare case proving the introduction and reception of Jiangnan Circle's Four Wangs' landscape style which was different in many aspects from Beijing Circle in the 19th century.