• Electronics and Telecommunications Trends
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• v.36 no.4
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• pp.1-12
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• 2021

The competition to lead the next generation of mobile technologies, 6G, is underway while the deployment of 5G has not been implemented worldwide. ITU-R plans to develop technical requirements and standards after completing the 6G Vision by 2023. It can be considered too early to have a concrete view of the 6G core network architecture from this timeline. However, major stakeholders have started making their presence felt by publishing their views. From updated analysis on the technology and service trends proposed, we present a list of research directions on 6G core network from several perspectives: distribution of network functions to nearer edge locations; future fixed-mobile convergence, including low earth orbit satellites; highly-precise QoS guarantee; supporting an extremely wide variety of service requirements; AI-native automation and intelligence; and aligning with the evolution of radio access network.

• Korean Journal of Environment and Ecology
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• v.31 no.1
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• pp.104-111
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• 2017

The construction of road tunnels and bridges have delivered driving efficiency and stability based on developed engineering technology. Tunnels have the advantage of reducing the deforested area compared with other road construction methods. Since a tunnel is an underground passageway dug through the surrounding soil/earth/rock and enclosed except for the entrance and exit, commonly at each end, it does not cause a large amount of deforestation. This study surveyed the deforested areas at each end of the tunnel by the design of the tunnel entrance and exit and forest topography to minimize the amount of deforestation caused by road construction. A survey was done on a total of 150 tunnels (300 entrances and exits) on several main roads in Korea. The deforested area of each tunnel was collected by a breakdown of the entrance area and the upper area of the tunnel. According to the results of Kruskal-Wallis analysis, it was found that there was statistically a significant relation between the location of tunnels and the amount of deforestation by the topographical access type of the tunnels. The tunnel with 'facing orthogonal to incline' type access caused the smallest deforestation while the the tunnel with 'facing to valley' and 'parallel with incline' type accesses caused large deforestation during tunnel construction. Tunnel positioning in the light of topography can reduce the deforested area by up to 1.5ha at each tunnel.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.2
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• pp.108-117
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• 2011

In drafting the standards on changes in current conditions, the height or the number of stories is applied in a restrictive manner by limiting to securing the distance to vertical surface for cultural properties within the influence investigation area, but this is expected to have a negative impact on the surrounding sceneries as well as results in the dwarfing phenomenon for precious cultural properties. That is, the preparation for supplementing the insufficient objectivity that is likely to take place during the process of drafting the standards on changes in current conditions. Thus the author attempts to suggest the analytic method for the decision making related to objective and reasonable determination and regulation of the changes in current conditions through computer based simulation work that considers the cultural properties and surrounding environments under investigation. In order to achieve such research objectives, the author reviewed the subject sites where the cultural property dwarfing phenomenon was expected to occur in case of the permission for the changes in current conditions or where the impact of natural landscape and natural feature on the earth is less than architectural building or artificial structure or where the new policy program is likely to be adopted due to incomplete establishment of current condition change standard within influence investigation area, among other cultural properties with architectural building or artificial structure nearby located in Cheonan city and then selected Cheonansaji Dangganjiju(flag poles) and Jiksanhyun Gwana(government office). The author then undertook the quantitative visibility analysis in order to determine the comprehensive prospect rights for the cultural properties and surrounding environments concerned.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.28 no.3
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• pp.98-104
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• 2010

The objective of this study was to understand the origin and characteristics of stone tower's style through the study of the 'Village Shrine at Seoji-ri, Andong'. The three kinds of stone towers were located forming a line of 9m on the hill of a red pine forest along the stream in the village. Toward the direction looking at the village, the three-story stone located on left, the two-story stone located in the middle, and the common style stone tower located on right. The bottom part of the three-story stone was 2.5m in length, 1.8m in width, 1.3m in height. The bottom part of the two-story stone was 1.3m in length, 1.5m in width, 0.9m in height. The common style stone heap tower was 3.0m in diameter, 1.8m in height with a cone shape. The small hat-shaped stone was presumed to be the top part of a three-story stone. According to the three factors(heaven, earth, human) of the idea of the universe in Korea, most ancient remains have components of odd numbers. Then it had been substituted with smaller three-story stone(at present, two-story stone). And then altered to a common stone tower later, such as the 'Village Shrine at Seoji-ri, Andong' that shows the combination of the Bronze Age's megalithic and a folk religion. The 'Village Shrine at Seoji-ri, Andong' is a valuable relic that shows the stone towers, and is derived from the Bronze Age. The 'Village Shrine at Seoji-ri, Andong' shows that the 'Village Shrine at Seoji-ri, Andong' was embodied the three-factor(heaven, earth, human) idea of the universe in three-story stone of megalithic culture' remains.

• KIEAE Journal
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• v.12 no.4
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• pp.13-19
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• 2012

The Earth's surface temperature still continues to rise, and extreme weather phenomena such as heat waves, drought, and precipitation have been repeated every year. It is reported that international communities attribute the main cause of the Earth's surface temperature rise to the excessive use of the fossil energy. Recently, the damage caused by climate change is getting worse, and the place where we live is suffering the most. Cities have been continuously growing not only meeting the basic functions of human habitation, work and leisure but also being places for various economic and social activities. But Cities, the victims of climate change, have grown only considering human needs and convenience rather than predicting their physical and ecological systems(Albedo effects, urban microclimate, resources and energy of the circulatory system, etc). In other words, the cities offer the cause of the problems of climate change, and even worsen the extreme weather phenomena without coping with them. Therefore, it is urgent priorities to protect the climate, to prevent the causes of the extreme weather phenomena and to enhance the adaptive capacity for the worse weather events. This study is to derive the concept for adapting to these climate changes which can make cities escape from exposure to these climate change impacts and make themselves safer places to live. And it analyzes some European cities and present developing models to implement planning methods. In this study, the concept of the climate adaptive cities will be suggested to prepare the adaptation measures for urban planners, and climate change adaptation models will be presented by analyzing some preliminary cases.

• Atmosphere
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• v.22 no.2
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• pp.267-277
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• 2012

The objectives of this study are to develop a real-time drought monitoring and prediction system on the East Asia domain and to evaluate the performance of the system by using past historical drought records. The system is mainly composed of two parts: drought monitoring for providing current drought indices with meteorological and hydrological conditions; drought outlooks for suggesting future drought indices and future hydrometeorological conditions. Both parts represent the drought conditions on the East Asia domain (latitude $21.15{\sim}50.15^{\circ}$, longitude $104.40{\sim}149.65^{\circ}$), Korea domain (latitude $30.40{\sim}43.15^{\circ}$, longitude $118.65{\sim}135.65^{\circ}$) and South Korea domain (latitude $30.40{\sim}43.15^{\circ}$, longitude $118.65{\sim}135.65^{\circ}$), respectively. The observed meteorological data from ASOS (Automated Surface Observing System) and AWS (Automatic Weather System) of KMA (Korean Meteorological Administration) and model-driven hydrological data from LSM (Land Surface model) are used for the real-time drought monitoring, while the monthly and seasonal weather forecast information from UM (Unified Model) of KMA are utilized for drought outlooks. For the evaluation of the system, past historical drought records occurred in Korea are surveyed and are compared with the application results of the system. The results demonstrated that the selected drought indices such as KMA drought index, SPI (3), SPI (6), PDSI, SRI and SSI are reasonable, especially, the performance of SRI and SSI provides higher accuracy that the others.

• 한국지구물리탐사학회:학술대회논문집
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• 2006.06a
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• pp.271-276
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• 2006

In this paper a polarimetric airborne SAR measurement has been used to study the radar polarimetric characteristics in the intertidal area on the south coastof the Korea. The L-band NASA/JPL airborne SAR (AIRSAR) data, which were acquired on the intertidal zone during PACRIM-II Korea campaign on September 30, 2000, were used for this research. The most intertidal zones of Yeoja Bay are composed of muddy soils with high silt and clay percentage. Models of microwave scattering from rough surfaces, i.e., semi-empirical model, and Extended Bragg model, were applied to investigate the surface characteristics of intertidal zones.

• Journal of the Korean earth science society
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• v.35 no.2
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• pp.115-130
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• 2014

The growing possibility of the disaster due to severe weather calls for disaster prevention and water management measures in South Korea. In order to prevent a localized heavy rain from occurring, the rainfall must be observed and predicted quantitatively. In this study, we developed an adjustment algorithm to estimate the radar precipitation applying to the local gauge correction (LGC) method which uses geostatistical effective radius of errors of the radar precipitation. The effective radius was determined from the errors of radar rainfall using geostatistical method, and we adjusted radar precipitation for four heavy rainfall events based on the LGC method. Errors were decreased by about 40% and 60% in adjusted hourly rainfall accumulation and adjusted total rainfall accumulation for four heavy rainfall events, respectively. To estimate radar precipitation for localized heavy rain events in summer, therefore, we believe that it was appropriate for this study to use an adjustment algorithm, developed herein.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.5
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• pp.19-27
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• 2005

The earth is a huge magnet. All organisms live under the magnetism of earth. The magnetism influences the ions in the cells of organisms and variously functions to lives as well. The medical treatment with magnet has come down from the ancient, it has an effect on the plants' growth. But there are no scientific studies about the influences of magnetism on plant growth. Accordingly, the experiment about the influence of magnetism on several foliage plants was carried out in this study. The promotion of plants' growth led by magnetism will be the method to save the management cost of horticultural market by early shipment. As a results of this experiment, plants treated with magnets showed excellent growth especially in length growth. The experiment results of the respective plants are the following. 1. Rhapis flabelliformis : This have grown so very well in the container lined with magnets as time goes by. Showing the significant(p<0.05) differences, the length growth of Height and Length of leaves was especially distinguished. 2. Howea belmoreana : This has grown well in all containers. Showing the significant(p<0.05) differences, the length growth of Height and Length of leaves was especially distinguished. 3. Chamaedorea seifrizii : There have been the growth differences between Height and Length of leaves as time goes by. The growth of Height and Length of leaves in the container lined with magnets has been excellent. The number of leaves and number of branch generally had no big differences but the growth of Height and Length of leaves was excellent in the magnet container. The method of plant growth promotion with magnet should save the management cost for this reason. Therefore the succeeding studies about the plant growth under the influence of magnet intensity and kind must be performed. The studies with various plants are needed to activate the program for growing plants with magnet.

• Advances in nano research
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• v.10 no.1
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• pp.77-90
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• 2021

In the present study, novel chitosan coated magnetic magnetite (Fe3O4) nanoparticles were successfully biosynthesized from mushroom, Agaricus campestris, extract. The obtained bio-nanocomposite material was used to investigate ultra-fast and highly efficient for removal of Ni2+ ions in a fixed-bed column. Chitosan was treated as polyelectrolyte complex with Fe3O4 nanoparticles and a Fungal Bio-Nanocomposite Material (FBNM) was derived. The FBNM was characterized by using X-Ray Diffractometer (XRD), Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy (SEM-EDS), Fourier Transform Infrared spectra (FTIR) and Thermogravimetric Analysis (TGA) techniques and under varied experimental conditions. The influence of some important operating conditions including pH, flow rate and initial Ni2+ concentration on the uptake of Ni2+ solution was also optimized using a synthetic water sample. A Central Composite Design (CCD) combined with Response Surface Modeling (RSM) was carried out to maximize Ni2+ removal using FBNM for adsorption process. A regression model was derived using CCD to predict the responses and analysis of variance (ANOVA) and lack of fit test was used to check model adequacy. It was observed that the quadratic model, which was controlled and proposed, was originated from experimental design data. The FBNM maximum adsorption capacity was determined as 59.8 mg g-1. Finally, developed method was applied to soft drinks to determine Ni2+ levels. Reusability of FBNM was tested, and the adsorption and desorption capacities were not affected after eight cycles. The paper suggests that the FBNM is a promising recyclable nanoadsorbent for the removal of Ni2+ from various soft drinks.