• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.599-609
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• 2021

A novel grounding system, which is presented in IEC 60364, has been adopted since 2021. A safety evaluation for the human body on the grounding system is required due to the various characteristics of the touch voltage and current passing when the human body experiences an electric shock. The Korea Electrical Safety Corporation (KESCO) and Korea Electric Association (KEA) have been conducting a safety technical education on the grounding system. On the other hand, it is difficult to instruct the electrical safety manager because of a lack of safety evaluations for the test equipment on the grounding system. Therefore, this paper modeled and implemented a test device for a safety evaluation depending on the grounding system of IEC 60364. Namely, this paper presents the modeling of the test device for a safety evaluation using PSCAD/EMTDC S/W, which is composed of an AC grid section, s test device section on the grounding system, and a sub-device section. This paper implemented a test device for safety evaluation, which consisted of an AC grid section, TT grounding system section, TN-S grounding system section, and monitoring section. From the simulation and test results with the safety characteristics of the human body in the TT and TN-S grounding system, when the fault impedances are 0[Ω], 10[Ω], and 100[Ω], the currents passing through the human body in the TT grounding system are 104[mA], 87.4[mA], and 35.5[mA], respectively. The corresponding currents in the TN-S grounding system are 54.9[mA], 4.1[mA], and 0.4[mA], respectively. Based on the results, the protection performance for an electric shock to the human body in the TN-S system is better than the TT system. This can be improved when the existing grounding system is changed from the TT system to the TN-S system.

• Korean Journal of Remote Sensing
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• v.38 no.6_3
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• pp.1827-1836
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• 2022

Disasters that occur unexpectedly are difficult to predict. In addition, the scale and damage are increasing compared to the past. Sometimes one disaster can develop into another disaster. Among the four stages of disaster management, search and rescue are carried out in the response stage when an emergency occurs. Therefore, personnel such as firefighters who are put into the scene are put in at a lot of risk. In this respect, in the initial response process at the disaster site, robots are a technology with high potential to reduce damage to human life and property. In addition, Light Detection And Ranging (LiDAR) can acquire a relatively wide range of 3D information using a laser. Due to its high accuracy and precision, it is a very useful sensor when considering the characteristics of a disaster site. Therefore, in this study, development and experiments were conducted so that the robot could perform real-time monitoring at the disaster site. Multi-sensor module was developed by combining LiDAR, Inertial Measurement Unit (IMU) sensor, and computing board. Then, this module was mounted on the robot, and a customized Simultaneous Localization and Mapping (SLAM) algorithm was developed. A method for stably mounting a multi-sensor module to a robot to maintain optimal accuracy at disaster sites was studied. And to check the performance of the module, SLAM was tested inside the disaster building, and various SLAM algorithms and distance comparisons were performed. As a result, PackSLAM developed in this study showed lower error compared to other algorithms, showing the possibility of application in disaster sites. In the future, in order to further enhance usability at disaster sites, various experiments will be conducted by establishing a rough terrain environment with many obstacles.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.3
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• pp.333-344
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• 2022

The quarrying and utilization of natural building stones such as granite and marble are rapidly emerging in developing countries. A huge amount of wastes is being generated during the processing, cutting and sizing of these stones to make them useable. These wastes are disposed of in the open environment and the toxic nature of these wastes negatively affects the environment and human health. The growth trend in the world stone industry was confirmed in output for 2019, increasing more than one percent and reaching a new peak of some 155 million tons, excluding quarry discards. Per-capita stone use rose to 268 square meters per thousand persons (m²/1,000 inh), from 266 the previous year and 177 in 2001. However, we have to take into consideration that the world's gross quarrying production was about 316 million tons (100%) in 2019; about 53% of that amount, however, is regarded as quarrying waste. With regards to the stone processing stage, we have noticed that the world production has reached 91.15 million tons (29%), and consequently this means that 63.35 million tons of stone-processing scraps is produced. Therefore, we can say that, on a global level, if the quantity of material extracted in the quarry is 100%, the total percentage of waste is about 71%. This raises a substantial problem from the environmental, economical and social point of view. There are essentially three ways of dealing with inorganic waste, namely, reuse, recycling, or disposal in landfills. Reuse and recycling are the preferred waste management methods that consider environmental sustainability and the opportunity to generate important economic returns. Although there are many possible applications for stone waste, they can be summarized into three main general applications, namely, fillers for binders, ceramic formulations, and environmental applications. The use of residual sludge for substrate production seems to be highly promising: the substrate can be used for quarry rehabilitation and in the rehabilitation of industrial sites. This new product (artificial soil) could be included in the list of the materials to use in addition to topsoil for civil works, railway embankments roundabouts and stone sludge wastes could be used for the neutralization of acidic soil to increase the yield. Stone waste is also possible to find several examples of studies for the recovery of mineral residues, including the extraction of metallic elements, and mineral components, the production of construction raw materials, power generation, building materials, and gas and water treatment.

• Journal of Korea Water Resources Association
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• v.54 no.11
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• pp.875-889
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• 2021

This study compares and analyzes the Soil and Water Assessment Tool (SWAT) and Terra MODIS (Moderate Resolution Imaging Spectroradiometer) as coniferous, deciduous and mixed forest with Yongdam Dam upstream (904.4 km²). The hydrologic evaluation period was set to 10 years from 2010 to 2019, and the applicability of the 8-day MOD15A2 Leaf Area Index (LAI) data, 3 TDR (Time Domain Reflectometry) (GB, JC, CC), and 1 Flux Tower (DU) evaporation volume (YDD) data was simulated. As a result, the R² of coniferous forest, deciduous forest and mixed forest are 0.95, 0.89, 0.90, soil moisture and evaportranspiration stations R² were analyzed at 0.50 to 0.55 and 0.51, respectively, with R² at 0.74, RMSE 2.75 mm/day, NSE 0.70 and PBIAS 14.3% for Yongdam inflow. Based on the calibrated and validated watersheds, the annual average evaportranspiration was calculated as coniferous 469.7 mm, deciduous 501. mm and 511.5 mm mixed forest, total runoff were estimated at coniferous 909.8 mm, deciduous 860.6 mm and 864.2 mm mixed forest. In the case of annual average evaportranspiration, it was evaluated that deciduous were high, but in the case of streamflow, it was evaluated that coniferous were high. Unlike other hydrologic with similar patterns throughout the year, the average annual evapotranspiration was about 7% higher than coniferous due to the higher evapotranspiration of deciduous with high leaf area index in summer and fall. In addition, deciduous were 9% and 6% higher for surface runoff and lateral flow, but the groundwater of coniferous was 77% higher. Therefore, it was confirmed that the total runoff was in order of coniferous, mixed forest, and deciduous.

• Journal of Environmental Impact Assessment
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• v.31 no.1
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• pp.11-46
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• 2022

This study was carried out to examine vascular plants and invasive alien plants in Gyodong Island, located at the northwestern Civilian Control Line (CCL) of Ganghwa-gun, Incheon, and to use them as basic data for systematic management of identified plants and establishing biodiversity conservation measures. The survey was conducted 13 times from April 2019 to August 2021. The vascularflora in Gyodong Island was identified as 109 families, 378 genera, 641 species, 15 subspecies, 49 variants, 8 forma, a total of 713 taxa. This was found to be about 15.36% of the total 4,641 taxa of vascular plants in Korea. The northern linage plants on the Korean Peninsula appearing in the Gyodong Island area were identified in 83 classification groups, including Red-based leaf edge (Carex erythrobasis H.Lev. & Vaniot). Korea endemic plants were identified as 16 taxa such as Seoul wild-ginger [Asarum heterotropoides var. seoulense (Nakai) Kitag.], and a total of 20 taxa of rare plants designated by IUCN were observed, including the endangered grade Beardless iris (Iris ruthenica Ker Gawl.). Floristic target species were classified with a total of 99 taxa. For V grade, Beardless iris 1 taxon was found. and also IV grade and III grade were identified in 8 taxa and 20 taxa respectively. The invasive alien plants identified as 75 taxa, such as Verbesina alternifolia (L.) Britton ex Kearney. The naturalization rate was 10.51%, and the urbanization index was calculated as 23.29%. Since large-scale construction has been currently underway on Hwagae Mt. in Gyodong Island as the target of survey area, the influx of invasive plants will be expected to promote. Therefore, it is urgent to establish in-situ protection and conservation measures for notable plants such as Beardless iris and Water smartweed [Persicaria amphibia (L.) S.F.Gray].

• Journal of the Korean Institute of Landscape Architecture
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• v.51 no.2
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• pp.103-119
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• 2023

Since the Korean government has decided to apply the policy of BIM (Building Information Modeling) to the entire construction industry, it has experienced a positive trend in adoption and utilization. BIM can reduce workloads by building model objects into libraries that conform to standards and enable consistent quality, data integrity, and compatibility. In the domestic architecture, civil engineering, and the overseas landscape architecture sectors, many BIM library standardization studies have been conducted, and guidelines have been established based on them. Currently, basic research and attempts to introduce BIM are being made in Korean landscape architecture field, but the diffusion has been delayed due to difficulties in application. This can be addressed by enhancing the efficiency of BIM work using standardized libraries. Therefore, this study aims to provide a starting point for discussions and present a classification system for objects and attribute information that can be referred to when creating landscape libraries in practice. The standardization of landscape BIM library was explored from two directions: object classification and attribute information items. First, the Korean construction information classification system, product inventory classification system, landscape design and construction standards, and BIM object classification of the NLA (Norwegian Association of Landscape Architects) were referred to classify landscape objects. As a result, the objects were divided into 12 subcategories, including 'trees', 'shrubs', 'ground cover and others', 'outdoor installation', 'outdoor lighting facility', 'stairs and ramp', 'outdoor wall', 'outdoor structure', 'pavement', 'curb', 'irrigation', and 'drainage' under five major categories: 'landscape plant', 'landscape facility', 'landscape structure', 'landscape pavement', and 'irrigation and drainage'. Next, the attribute information for the objects was extracted and structured. To do this, the common attribute information items of the KBIMS (Korean BIM Standard) were included, and the object attribute information items that vary according to the type of objects were included by referring to the PDT (Product Data Template) of the LI (UK Landscape Institute). As a result, the common attributes included information on 'identification', 'distribution', 'classification', and 'manufacture and supply' information, while the object attributes included information on 'naming', 'specifications', 'installation or construction', 'performance', 'sustainability', and 'operations and maintenance'. The significance of this study lies in establishing the foundation for the introduction of landscape BIM through the standardization of library objects, which will enhance the efficiency of modeling tasks and improve the data consistency of BIM models across various disciplines in the construction industry.

• Journal of the Korean Institute of Landscape Architecture
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• v.51 no.1
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• pp.13-28
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• 2023

This study examines the process of project promotion in Busan, which introduced the private participation-type consultative body for the first time in the country in the promotion stage of the private-initiated park development project, and introduced flexible application of the system and differentiated policy elements in the implementation process, and examines the operational characteristics and we tried to analyze performance, etc. As a result of the analysis, first, the preferred bidder was selected by introducing a mixed method in the project method, which is an independent project method that cannot be seen in other local governments. Second, by specifying guidelines considering the characteristics of each park and detailed guidelines such as the location, area, and maximum height of non-park facilities, criteria for establishing a rational development plan utilizing regional identity and the basis of evaluation standards were laid. Third, in the project process, transparency was secured through the delegation-type roundtable, in which the private sector performs the functions and roles of key actors, thereby preventing disputes such as suspicion of preferential treatment. Fourth, in order to improve the quality of park facilities to be donated and to secure design adequacy, after approval of the implementation plan, a general planner was introduced and construction project management (design stage) services were performed to promote efficient implementation and specialization of luxury parks in the region. As a result, the city of Busan carried out the project efficiently by conserving 5 parks from sunset, a park area of 2.25km², and reducing land compensation and park construction costs by KRW 740 billion. Reinforcement of the public nature of the private-initiated park development project was suggested. However, due to the application of these systems and verification procedures, the project period is prolonged, and park services are delayed along with the financial burden on private operators.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.5A
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• pp.407-415
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• 2010

In Korea, more than 90% of the total number of steel bridges built for 40~70 m span length is a steel box-girder bridge type. A steel box-girder bridge is suitable for long span or curved bridges with outstanding flexural and torsional rigidity as well as good constructability and safety. However, a steel box-girder bridge is uneconomical, requiring many secondary members and workmanship such as stiffeners and ribs requiring welding attachments to flanges or webs. Therefore, in US and Japan, a plate girder bridge, which is relatively cheap and easy to construct is generally used. One type of the plate girder bridge is the two- or three-main girder plate bridge, which is a composite plate girder bridge that minimizes the number of required main girders by increasing the distance between the adjacent girders. Also, for the simplification of girder section, the stiffener which requires attachment to the web is not required. The two-main steel girder plate bridge is a representative type of plate girder bridges, which is suitable for bridges with 10 m effective width and has been developed in the early 1960s in France. To ensure greater safety of two- or three-main girder plate bridges, a larger steel section is used in the bridge domestically than in Europe or Japan. Also, the total number of two- or three-main girder plate bridge constructed in Korea is significantly less than the steel box girder bridge due to a lack of designers' familiarity with more complex design detailing of the bridge compare to that of a steel box girder bridge design. In this study, a new construction method called Turn Over method is proposed to minimize the steel section size used in a two- or three-main girder plate bridge by applying prestressing force to the member using confining concrete section's weight to reduce construction cost. Also, a full scale 20 m Turn Over girder specimen and a Turn Over girder bridge specimen were tested to evaluate constructability and structural safety of the members constructed using Turn Over process.

• The Korean Journal of Air & Space Law and Policy
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• v.20 no.1
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• pp.9-43
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• 2005

The Korean government established her first "National Space Program" in 1996, and revised it in 2000 and 2005. As embedded in the National Space Program, Korea aims to become one of the world's top countries in space technology by 2010. All of 13 satellites are planned to be put into orbit as schematized, which include 7 multi-purpose satellites, 4 science satellites and 2 geostationary orbit satellites. The Space Center in Korea is to be built at Woinara-Do, Bongrae-Myon, Koheung-Goon, Junlanam Province on the southern coast of the Korean peninsular. The first phase of the construction of the space center will be finished by 2007 for launch of KSLV-l. This will make Korea be the 13th advanced country in space development having a launching site in the world. The "Space Center" will serve as the infrastructure for the development of space technology and related technology, and plan to launch a low earth orbit satellite in 2007. A second science satellite made in Korea will be launched from the space center by 2007. From 2010, the center will be operated on a commercial basis operating launch facilities for low-to mid-altitude orbit satellites. Since the 'Aircraft Industry Promotion Act' was replaced by the 'Aerospace Industry Development Promotion Acf of 1987, this Act had been amended seven times from 1991 year to 2004. Most of developed countries has been enacted the space law including the public or private items such as an (1)DSA, (2)Russia, (3)the United Kingdom, (4)Germany, (5)France, (6)Canada, (7)Japan, (8)Sweden, (9)Australia, (10)Brazil, (11)Norway, (12)South Africa, (13)Argentina, (14)Chile, (15)Ukrainian etc. As the new Space Exploration Promotion Act was passed by the resolution of the Korean Congress on May 3, 2005, so the Korean government has made the public proclamation the abovementioned Act on May 31, this year. This Act takes effect on December 1, 2005 after elapsing six months from the date of promulgation. The main contents of Space Exploration Promotion Act of 2005 is as the following (1)establishing a basic plan for promoting space exploration, (2)establishment and function of national space committee, (3)procedure and management of domestic and international registration of space objects, (4)licensing of launch by space launch vehicles, (5)lability for damages caused by space accidents and liability insurance, (6) organizing and composition of the space accident investigation committee, (7)Support of non-governmental space exploration project, (8)Requesting Support and Cooperation of Space Exploration, (9)Rescue of Astronauts and Restitution of Space Objects, etc.. In oder to carry out successfully the medium and long basic plan for promoting space exploration and to develope space industry in Korea, I think that it is necessary for us to enlarge and to reorganize the function and manpower of the Space Technology Development Division of the Ministry of Science & Technology and the Korea Aerospace Research Institute. Korea has been carrying out its space program step by step according to the National Space Program. Korea also will continually strengthen the exchange and cooperation with all the countries in the world under the principle of equality, friendship relations and mutual benefits. Together with all other peoples around the globe, Korea will make due contribution towards the peaceful utilization of space resources and promotion of human progress and prosperity.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.40 no.2
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• pp.1-13
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• 2022

This paper examined the history and development of Gyeongbokgung Palace's back garden based on historical materials and drawings such as Joseon Ilgi(Diaries of Joseon Dynasty), Joseon Wangjo Sillok(the Annals of the Joseon Dynasty), Doseongdaejido(the Great Map of Seoul), Bukgwoldohyeong(Drawing Plan of the Northern Palace), the Bukgung Palace Restoration Plan, Restoration Planning of Gyeongbokgung Palace and the following results were derived. First, it was confirmed that the Back Garden of Gyeongbokgung Palace was famous for its great location since the Goryeo Dynasty, and that it was named Namkyeong at that time and was a place where a shrine was built, and that castles and palaces were already built during the Goryeo Dynasty under the influence of Fengshui-Docham(風水圖讖) and Zhouli·Kaogongji(周禮考工記). Although the back garden of Gyeongbokgung Palace in the early Joseon Dynasty stayed out of the limelight as a back garden for the palace, it has a place value as a living space for the head of the state from King Gojong to the present. Second, in order to clearly identify the boundaries of back garden, through literature such as map of Doseongdo (Map of the Capital), La Coree, Gyeongmudae Area, Japanese Geography Custom Compendium, Korean Photo Album, JoseonGeonchukdoJip(The Illustration Book of Joseon Construction), Urban Planning Survey of Gyeongseong, it was confirmed that the current Blue House area outside Sinmumun Gate was built outside the precincts of Gyeongbokgung Palace. It was found that the area devastated through the Japanese Invasion of Korea in 1592, was used as a space where public corporations were combined through the process of reconstruction during the King Gojong period. In Japanese colonial era, the place value as a back garden of the primary palace was damaged, as the palace buildings of the back garden was relocated or destroyed, but after liberation, it was used as the presidential residence and restored the place value of the ruler. Third, in the back garden of Gyeongbokgung Palace, spatial changes proceeded through the Japanese Invasion and Japanese colonial era. The place with the greatest geographical change was Gyeongnongjae area, where the residence of the Japanese Government-General of Korea was built, and there were frequent changes in the use of the land. On the other hand, the current Gyeongmudae area, the forests next to the small garden, and the forests of Baekak were preserved in the form of traditional forests. To clarify this, 1:1200 floor plan of inner Gyeongmudae residence and satellite images were overlapped based on Sinmumun Gate, and as a result, it was confirmed that the water path originating from Baekak still exists today and the forest area did not change. Fourth, in the areas where the traditional forest landscape was inherited, the functional changes in the topography were little, and major old-age colonies are maintained. The old trees identified in this area were indicator tree species with historical value. Representatively, Pinus densiflora for. multicaulis Uyeki, located in Nokjiwon Garden, is presumed to have been preserved as one of Pinus densiflora for. multicaulis Uyeki planted next to Yongmundang, and has a historicality that has been used as a photo zone at dinners for heads of state and important guests. Lastly, in order to continuously preserve and manage the value of Gyeongbokgung Palace in Blue House, it is urgent to clarify the space value through excavation of historical materials in Japanese colonial era and establish a hierarchy of garden archaeology by era. In addition, the basis for preserving the historical landscape from the Joseon Dynasty to the modern era from Gyeongbokgung Palace should not damage the area of the old giant trees, which has been perpetuated since the past, and a follow-up study is needed to investigate all the forests in Blue House.