• Acta Via Serica
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• v.8 no.2
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• pp.25-52
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• 2023

The astronomic observatory of Graw Village is located on Mount Dari Lolikan, facing the village. Graw is located in the foothills of Mount Ser-i-Rash, 25 km northeast of Erbil Governorate, Iraq. This study attempts to clarify the foundations of this observatory, its components, as well as the founder and the date of its establishment. The study made efforts to clarify the benefits of this calendar to local residents in their daily lives. The database for this study is based on direct observation of the observatory station. The observation included the recording date and position of sunset and the appearance of stars throughout the year. Observation and documentation for both sunset and stars were performed over several years due to weather conditions since observation was not possible on foggy and rainy days and nights. Each observation took five to ten minutes depending on the clarity of the sky. The observatory consists of a group of stone cones. Each cone was built by stones in a specific location after careful and long observation of the sunset. Efforts were made to observe the disappearance and reappearance of the stars based on the change in the position of the Earth in relation to the sun. Graw's calendar helped to recognize important times of the year, such as the winter and summer forties, which were very important, especially when snow covered the roads, transportation stopped, crops spoiled, and pets stayed in their barn. The most important features of the winter forties are the memories, experiences, and minds of the villagers' ancestors. The forties were associated with the arrival of cold and heavier rain throughout the year, which is consistent with modern science, as the angle at which the Earth rotates increases the number and activity of weather depressions that affect the study area during this period. This observatory has a close connection with the daily life of the villagers, especially in the past centuries. It helped the people of the area in their appointments to carry out their work in the field of agriculture. The observatory was also of great importance in the field of education in the past centuries, especially in traditional religious schools. It also appears from this research that the calendar has ancient roots, which extend back thousands of years, as evidenced by the Ezidis who follow an ancient religion whose roots extend back thousands of years and who fast during both the winter and summer forties annually, with the participation of people in various regions of the world. It is not known who made this astronomic observatory but most of the oral information that has been passed down to us by word of mouth agrees on both Mullah Abdullah Al-Kurdi and Mullah Omar. Likely, this astronomic observatory was built around the late 17^th and early 18^th centuries.

• Atmosphere
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• v.34 no.2
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• pp.139-151
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• 2024

The Yeongdong region has suffered from severe snowstorms and the relevant damage such as traffic accidents on slippery roads, and the collapse of greenhouses and temporary buildings. While a lot of research on snowfall has been conducted, the detailed study of snow crystals' phase and habit through intensive observations and the relevant microphysical analysis is still lacking. Therefore, a snowflake camera, PARSIVEL, and intensive radiosonde soundings were utilized to investigate phase and habit changes in solid precipitation. Two remarkable episodes of phase and habit changes were selected such as 19 March 2022 and 15 February 2023. Both events occurred in the synoptic condition of the High in the north and the Low passing by the south, which was accompanied by rapid temperature cooling below 2.5 km. During the events of a short period between 3 to 6 hours, the temperature at 850 hPa decreased by about 4 to 6℃. This cooling led to a change in the main habit of snow particles from riming to aggregate, identified with both MASC and PARSIVEL. Meanwhile, the LDAPS model analyses do not successively represent the rapid cooling and short-term variations of solid precipitation, probably by virtue of overestimating low-level equivalent potential temperature during these periods. The underlying causes of these the low-level temperature variations within 6 hours, still remain unclear. It might be associated with mesoscale orographic phenomenon due to the mountains and East Sea effects, which certainly needs an intensive and comprehensive observation campaign.

• Journal of Ecology and Environment
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• v.47 no.4
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• pp.282-289
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• 2023

Background: As wildlife habitats are being destroyed and growth environments are changing, the survival of animals and plants is under threat. Epilobium hirsutum L., a species that inhabits wetlands, has held legally protected status since 2012. However, no specific measures are currently in place to protect its habitat, leading to a decline in remaining populations as a result of land use change and human activities. Results: The growth environment (including location, climate, land use, soil, and vegetation) of the five habitat sites (Samcheok, Taebaek1, Taebaek2, Cheongsong, Ulleung) of E. hirsutum L. was investigated and analyzed. These habitats were predominantly situated in flat areas with gentle south-facing slopes, at an average altitude of 452.7 m (8-726 m) above sea level in Gangwon-do and Gyeongsangbuk-do. The average annual temperature ranged 11.5℃ (9.2℃-12.9℃), whereas the average annual precipitation ranged 1,304.5 mm (1,062.7-1,590.7 mm). The surrounding land use status was mainly characterized by mountainous areas, and human interference, such as agricultural land and roads, was commonly found in proximity to these natural habitats. Soil physicochemical analysis revealed that the soil was predominantly sandy loam with a slightly high sand content. The average pH measured 7.64, indicating an alkaline environment, and electrical conductivity (EC) averaged 0.33 dS/m. Organic matter (OM) content averaged 66.44 g/kg, available phosphoric acid (P₂O₅) content averaged 115.73 mg/kg, and cation exchange capacity (CEC) averaged 23.43 cmolc/kg. The exchangeable cations ranged 0.09-0.43 cmol⁺/kg for potassium (K), 10.23-16.21 cmol⁺/kg for calcium (Ca), 0.67-4.94 cmol⁺/kg for magnesium (Mg), and 0.05-0.74 cmol⁺/kg for sodium (Na). The vegetation type was categorized as E. hirsutum community with high numbers of E. hirsutum L., Persicaria thunbergii (Siebold & Zucc.) H. Gross, Phragmites japonica Steud., Humulus japonicus (Siebold & Zucc.), and Bidens frondosa L.. An ecological flora analysis, including the proportion of lianas, naturalized plants, and annual herbaceous plants, revealed that the native habitat of E. hirsutum L. was ecologically unstable. Conclusions: Analysis of the habitat of E. hirsutum L., a class II endangered wildlife species, provided essential data for local conservation and restoration efforts.

• The Journal of Engineering Geology
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• v.34 no.1
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• pp.39-49
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• 2024

The construction of underground infrastructure is garnering growing increasing research attention owing to population concentration and infrastructure overcrowding in urban areas. An important associated task is establishing a monitoring system to evaluate stability during infrastructure construction and operation, which relies on developing techniques for ground investigation that can evaluate ground stability, verify design validity, predict risk, facilitate safe operation management, and reduce construction costs. The method proposed here uses satellite imaging in a cost-effective and accurate ground investigation technique that can be applied over a wide area during the construction and operation of infrastructure. In this study, analysis was performed using Synthetic Aperture Radar (SAR) data with the time-series radar interferometric technique to observe surface displacement during the construction of urban underground roads. As a result, it was confirmed that continuous surface displacement was occurring at some locations. In the future, comparing and analyzing on-site measurement data with the points of interest would aid in confirming whether displacement occurs due to tunnel excavation and assist in estimating the extent of excavation impact zones.

• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.1
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• pp.63-71
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• 2024

Through the development of construction technology, various construction projects such as redevelopment projects, undergrounding of roads, expansion of subways, and metro railways are being carried out. However, this has led to an increase in the number of construction projects in existing urban centers and neighborhoods, resulting in an increase in the number of damages and disputes between neighboring buildings and residents, as well as an increase in safety accidents due to the aging of existing buildings. In this study, digital data was applied to a graphics program to objectify the progress of cracks by comparing the creation of cracks and the increase in length and width through photographic images and presenting the degree of cracks numerically. Through the application of the program, the error caused by the subjective judgment of crack change, which was mentioned as a shortcoming of the existing field survey, was solved. It is expected that the program can be used universally in the building diagnosis process by improving its reliability if supplemented and improved in the process of use. As a follow-up study, it is necessary to apply the extraction algorithm of the digital graphic data program to calculate the length and width of the crack by itself without human intervention in the preprocessing work and to check the overall change of the building.

• Journal of the Korean Association of Geographic Information Studies
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• v.27 no.1
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• pp.29-40
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• 2024

Recently, the technology of autonomous driving, one of the core of the fourth industrial revolution, is developing, but sensor-based autonomous driving is showing limitations, such as accidents in unexpected situations, To compensate for this, HD-map is being used as a core infrastructure for autonomous driving, and interest in the public and private sectors is increasing, and various studies and technology developments are being conducted to secure the latest and accuracy of HD-map. Currently, NGII will be newly built in urban areas and major roads across the country, including the metropolitan area, where self-driving cars are expected to run, and is working to minimize data error rates through quality verification. Therefore, this study analyzes the spatial relationship of reference objects in the attribute structuring process for rapid and accurate renewal and production of HD-map under construction by NGII, By applying the attribute input automation methodology of the reference object in which spatial relations are established using the library of open source-based PyQGIS, target sites were selected for each road type, such as high-speed national highways, general national highways, and C-ITS demonstration sections. Using the attribute automation tool developed in this study, it took about 2 to 5 minutes for each target location to automatically input the attributes of the spatial relationship reference object, As a result of automation of attribute input for reference objects, attribute input accuracy of 86.4% for high-speed national highways, 79.7% for general national highways, 82.4% for C-ITS, and 82.8% on average were secured.

• Journal of Korean Tunnelling and Underground Space Association
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• v.26 no.3
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• pp.223-242
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• 2024

Single-shell tunnels, introduced to South Korea in the early 2000s, have not been adopted for the main tunnels of roads or railways over the past two decades despite several attempts starting with the Gwangju City Bypass. This reluctance likely arises from concerns about the long-term performance of supporting materials and the absence of relevant criteria and specifications. However, recent progress, including the incorporation of high-strength shotcrete standards and corrosion-resistant rock bolt specifications, alongside equipment and technique enhancements, necessitates a reassessment of single-shell tunnels. While the single-shell tunnel method offers advantages in environmental impact, construction cost and period compared to the conventional NATM, it is crucial to address the challenges, such as limited design and construction experience, incomplete detailed standards, and insufficient construction specifications, through further research and pilot projects. This paper reviewed the basic principles of single-shell tunnel, current application and research status, technical development trends, criteria and specifications, and remaining challenges. It aims to reignite discussions on the feasibility of applying single-shell tunnels in South Korea.

• Korean Journal of Environmental Biology
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• v.42 no.1
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• pp.62-79
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• 2024

Garlic mustard (Alliaria petiolata) is a species that has devastated the United States and Canada. It is known to play a role in destroying the ecosystem. In this study, the domestic distribution of garlic mustard was confirmed and a detailed distribution map was created for the Samcheok region, where the largest population has been established in South Korea. This study investigated the growth environment, life cycle, and population dynamics of the species in the Samcheok region. Garlic mustard was found in a total of 301 locations in Samcheok, with a total distribution area of 2,957 square meters. Annual plants germinated in mid-April, overwintered in rosette form, underwent vegetative growth from April 10 to April 24 the following year, and flowered from April 24 to May 7. Individuals producing seeds began to die off from June. Both annual and biennial individuals showed a trend of increasing and then decreasing in number around April 27 (118 days). Garlic mustard grew well under favorable light conditions in early spring. They showed less growth on leaf litter, short distance from roads, lower altitude, deciduous broad-leaved forest of middle and lower parts of the slope and forest edge. Without proper control measures in the Samcheok region, it is likely to spread more rapidly in deciduous broad-leaved forests along hiking trails in the Galyasan Mountains. In particular, it is more likely to extend to oak community where light enters the site during flowering than to pine community where there is less light in the site.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.2
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• pp.122-129
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• 2016

It is important to know the sensitivity of shrubs to de-icing salt in order to set guidelines for ecological tolerance of evergreen shrubs along roads. Therefore, the aim of this study was to investigate the influence of de-icing salt, calcium chloride($CaCl_2$), on the growth and physiological characteristics of three evergreen shrubs, Euonymus japonica, Rhododendron indicum, and Buxus koreana. Plants were exposed to calcium chloride at different concentrations(weight percentage, 0% as control, 1.0%, 3.0%, and 5.0%) through amended soil maintained from the start of the experiment in October of 2014 until termination in March of 2015. The survival rate, plant height, leaf length, leaf width, leaf shape index, number of leaves, fresh weight, dry weight, dry matter, root/top ratio, chlorophyll contents, fluorescence, photosynthesis, stomatal conduct, and transpiration rate were recorded. Elevated calcium chloride concentrations decreased plant height, leaf length, leaf width, leaf shape index, fresh weight, dry weight, dry matter, and R/T ratio of the three shrubs. Root growth responded more sensitively than the top growth to salinity. However Euonymus japonica was more tolerant to salt stress than Rhododendron indicum and Buxus koreana. Their growths were totally inhibited by $CaCl_2$ above 3.0% and 1.0% concentrations, respectively. Chlorophyll content, fluorescence, photosynthesis, stomatal conduct, and transpiration rate of both Rhododendron indicum and Buxus koreana were reduced sharply, while Euonymus japonica exhibited mild reductions compared to plants grown in control when increasing calcium chloride was used. Especially, the transpiration rates of Rhododendron indicum, and the photosynthesis and stomatal conduct of Buxus koreana were suppressed as the concentrations of calcium chloride increased. Therefore, Euonymus japonica should be considered as an ecologically tolerant species with proven tolerance to de-icing salt.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.2
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• pp.583-595
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• 2014

Currently, Korean transportation policies are aiming for increase of safety and environment-friendly and efficient operation, by avoiding construction and expansion of roads, and upgrading road alignments and facilities. This is revealed by that there have been 22 road expansion projects (30%) and 50 road improvement projects (70%) under the 3rd Five-Year Plan for National Highways ('11~'15), while there were 53 road expansion projects (71%) and 22 road improvement projects (29%) under the 2nd Five-Year Plan for National Highways. For more effective road improvement projects, there is a need of choosing projects after an objective and scientific safety assessment of each road, and assessing safety improvement depending on projects. This study is intended to develop a model for this road safety analysis and assessment. The major objective of this study is creating a road safety analysis and assessment model appropriate for Korean society, based on the HSM (Highway Safety Manual) of the U.S. In order to build up data for model development, the sections thought to have identical geometrical structure factors in 5 lines, Cheonbuk province, were divided as homogeneous sections, and representative values of geometric structures, facilities, traffic volume, climate conditions and land usage were collected from the 1,452 sections divided. In order to build up data for model development, the sections thought to have identical geometrical structure factors in 5 lines, Cheonbuk province, were divided as homogeneous sections, and representative values of geometric structures, facilities, traffic volume, climate conditions and land usage were collected from the 1,452 sections divided. The collected data was processed correlation analysis of each road element was implemented to see which factor had a big effect on traffic accidents. On the basis of these results, then, an accident model was established as a negative binomial regression model.Using the developed model, an Crash Modification Factor (CMF) which determines accident frequency changes depending on safety performance function (SPF) predicting the number of accident occurrence through traffic volume and road section expansion, road geometric structure and traffic properties, was extracted.