• Korean Journal of Materials Research
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• v.32 no.1
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• pp.9-13
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• 2022

Bullets flying with a light from the back are called "tracers". Tracers are ignited by the combustion gas of the propellant and emit bright light that allows the shooter to visually trace the flight path. Therefore, tracers mark the firing point for allies to assist shooters to hit target quickly and accurately. Conventional tracers are constructed with a mixture of an oxidizing agent, raw metal, and organic fuel. Upon ignition, the inside of the gun can be easily contaminated by the by-products, which can lead to firearm failure during long-term shooting. Moreover, there is a fire risk such as forest fires due to residual flames at impact site. Therefore, it is necessary to develop non-combustion type luminous material; however, this material must still use the heat generated from the propellant, so-called "thermoluminescence (TL)". This study aims to compare the TL emission of Dy³⁺, La³⁺ and Ho³⁺ doped MgB₄O₇ phosphors prepared by solid state reaction. The crystal structures of samples were determined by X-ray diffraction and matched with the standard pattern of MgB₄O₇. Luminescence of various doses (200 ~ 15,000 Gy) of gamma irradiated Dy³⁺, La³⁺ and Ho³⁺ (at different concentrations of 5, 10, 15 and 20 %) doped MgB₄O₇ were recorded using a luminance/color meter. The intensity of TL yellowish (CIE x = 0.401 ~ 0.486, y = 0.410 ~ 0.488) emission became stronger as the temperature increased and the total gamma-ray dose increased.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.41 no.2
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• pp.26-34
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• 2023

This study conducted interviews with former and current managers of Cheongwadae landscape architecture to provide basic information necessary to preserve, manage, and utilize Gyeongbokgung Palace's back garden, and the main conclusions summarized are as follows. First, the topography changed a lot with the construction of the main building and the official residence under President Roh Tae-woo. The water system was connected to Gyeongbokgung Palace in the past, but is now disconnected. Second, in the case of planting, the most important principles were the president's security and protocol, and accordingly, trees were placed or managed. Trees were planted by introducing excellent trees in various regions, and wildflowers and ground cover plants were frequently replaced according to the season. Third, facilities and roads were arranged for the president's protocol, hobbies, and workers' rest, and fire-fighting facilities were installed to prevent disaster in the forest area of Baegaksan Mountain. Fourth, the biggest inflection point of Gyeongbokgung Palace's back garden during Cheongwadae period was the change in topography due to the new construction of the main building and official residence during President Roh Tae-woo, the removal of A and B barbed wire fences that separated space during President Roh Moo-hyun, and the extensive landscaping carried out for the G20 Summit under President Lee Myung-bak. The area of Gyeongbokgung Palace's back garden is expected to face another inflection point due to the opening of Cheongwadae on May 10, 2022, and the work of evaluating the historical, academic, and landscape values of Gyeongbokgung Palace's back garden should be carried out while preserving the status.

• Journal of the Society of Disaster Information
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• v.14 no.3
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• pp.238-246
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• 2018

Purpose: The purpose of this study is to examine the directions for establishing a disaster safety village in rural areas where damage from a similar type of disaster occurs repeatedly by conducting the consciousness survey targeting at experts and disaster safety officials in a local government. Method: The risks of disaster in rural areas were examined and the concept and characteristics of disaster safety village which is a measure on the basis of Myeon (township) among the measures of village unit were examined in order to carry out this study. In addition, opinion polling targeting at officials-in-charge in the local government and survey targeting at experts in disaster safety and building village were conducted. Based on the findings, the directions for establishing a disaster safety village that fitted the characteristics of rural areas were examined. Result: The officials-in-charge in the local government answered that rural areas have a high risk of storm and flood such as heavy snowing, typhoon, drought, and heavy rain as well as forest fire, and it is difficult to draw voluntary participation of farmers for disaster management activities due to their main duties. They also replied that active support and participation of residents in rural areas are necessary for future improvement measures. The experts mostly replied that the problem of disaster safety village project is a temporary project which has low sustainability, and the lack of connections between the central government, local governments and residents was stressed out as the difficulties. They said that measures to secure the budget and the directions of project promotion system should be promoted by the central government, local governments and residents together. Conclusion: The results of this study are as follows. First, a disaster safety village should be established in consideration of the disaster types and characteristics. Second, measures to secure the budget for utilizing the central government fund as well as local government fund and village development fund should be prepared when establishing and operating a disaster safety village in rural areas. Third, measures to utilize a disaster safety village in rural areas for a long period of time such as the re-authorization system should be prepared in order to continuously operate and manage such villages after its establishment. Fourth, detailed measures that allow residents of rural areas to positively participate in the activities for establishing a disaster safety village in rural areas should be prepared.

• Journal of the Society of Disaster Information
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• v.17 no.3
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• pp.415-426
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• 2021

Purpose: The purpose of this study is to create the deveopment plan for promotion of advanced disaster-safety awareness, which is noted as a major factor in the large disaster. Method: This study is to conduct theoretical review with regard to disaster management and safety awareness. Consciousness surveys on safety awareness and previous disaster case was analyzed to derive the cause of the disaster, and the development plan for promotion of advanced disaster-safety awareness was suggested. Result: In the survey on the public's sense of safety on the disaster management evaluation, 'Response' stage was well performed, but the 'Recovery' stage was not. Especially, it was found that disaster safety education at the 'Prevention' stage was very lacking. In the survey on the public's safety awareness, the awareness level of the evacuation facility was very low, information on infectious diseases and collapse accident was insufficient. Especially, it has been found that the awareness on safety regulation in daily life is very insufficient. Through the case study on previous disaster(COVID-19, Fire in Miryang Sejong Hospital, Forest fire in the east coas at 2004'), it was derived that the lack of safety awareness(such as safety insensitivity) was the main factor of the expansion of the damage scale. Conclusion: The development plan for promotion of advanced disaster-safety awareness are as follow. First, it is necessary to spread the safety culture movement through the expansion of safety education and safety promotion. Second, disaster confrontation training for the public should be implemented to improve the effectiveness of disaster response. Finally, it is necessary to change the individual awareness on safety. When these factors are implemented systematically, advanced disaster-safety awareness can be promoted. Ultimately, disaster accidents in our society can be reduced.

• Korean Journal of Environment and Ecology
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• v.26 no.4
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• pp.512-527
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• 2012

Jangdo Island (area $1.54km^2$) located in the western end of Dadohae Haesang National Park has been recognized as an prominent ecoregion possessing high moor and national biodiversity hotspot. In terms of the Z$\ddot{u}$rich-Montpellier School's phytosociology, we investigate the diversity of plant communities on the island and reevaluate the Jangdo wetland designated as Ramsar site. Ten physiognomic types of the Jangdo's vegetation were classified into 22 syntaxa (3 associations, 15 communities and 4 subcommunities). Jangdo wetland was actually denominated as 'eutrophic wetland' by Pharagmitetea and Orizetea rather than 'high moor'. Nevertheless, existence value of the Jangdo wetland is evaluated very high as a stepping stone for migratory birds and even plant dispersions. A new site of the northernmost distribution of Arachniodo-Castanopsietum sieboldii, which is a kind of cold-resistant phytocoenosis among the Camellietea japonicae of the warm-temperate broad-leaved forests, was described. Hosta yingeri-Carpinus turczaninovii var. coreana community and Carex wahuensis var. robusta-Juniperus chinensis var. procumbens community were described specifically as an endemic and an edaphic vegetation type, respectively. The unique Jangdo's vegetation reflects regional environmental conditions such as much higher frequency of frost-free days and the highest number of annual average foggy days in Korea and a well-developed aquifer in the depressed basin formed by differential erosion. We identified that human interventions (pasture, logging, forest fire, cultivation, etc.) has been involved intensively on every vegetation types, even though a rugged and inaccessible topography of the island. Particularly the Jangdo wetland has been recently threatened by fundamental distortion on hydrological system. We request an immediate establishment of the conservation prescription manual.

• Korean Journal of Remote Sensing
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• v.24 no.2
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• pp.189-194
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• 2008

Middle-infrared (MIR) spectral region between 3.0 and $5.0\;{\mu}m$ in wavelength is useful for observing high temperature events such as volcanic activities and forest fire. However, atmospheric effects and sun irradiance in day time has not been well studied for this MIR spectral band. The objectives of this basic study is to evaluate atmospheric effects and eventually to estimate surface temperature from a single channel MIR image, although a typical approach utilize split-window method using more than two channels. Several parameters are involved for the correction including various atmospheric data and sun-irradiance at the area of interest. To evaluate the effect of sun irradiance, MODIS MIR images acquired in day and night times were used for comparison. Atmospheric parameters were modeled by MODTRAN, and applied to a radiative transfer model for estimating the sea surface temperature. MODIS Sea Surface Temperature algorithm based upon multi-channel observation was performed in comparison with results from the radiative transfer model from a single channel. Temperature difference of the two methods was $0.89{\pm}0.54^{\circ}C$ and $1.25{\pm}0.41^{\circ}C$ from the day-time and night-time images, respectively. It is also shown that the emissivity effect has by more largely influenced on the estimated temperature than atmospheric effects. Although the test results encourage using a single channel MR observation, it must be noted that the results were obtained from water body not from land surface. Because emissivity greatly varies on land, it is very difficult to retrieval land surface temperature from a single channel MIR data.

• Korean Journal of Heritage: History & Science
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• v.46 no.4
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• pp.48-63
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• 2013

The results of the study on the space planning and landscape design of Unjoru(雲鳥樓) through the 'Jeolla Gurye Omidong Gado(全羅求禮五美洞家圖)' drawn using GyeHwa(界畵) technique are as follows. First, 'Omidong Gado' is believed to date back to the period when Unjoru(1776~1783) was established for the following reasons: (1) The founder, Yoo-IJu(柳爾?), sent the drawing for the house while he was serving as the governor of YongCheon county(龍川府史). (2) It shows the typical dwelling houses' space division and its location is in a good spot with mountain in the back and water in front(背山臨水) and there is every indication of scheme drawing. (3) Front gate was changed and remodeled to a lofty gate in 1804. Second, Nogodan & Hyeongjebong of Jiri Mountain sit at the back of Unjoru, and faces Obong mountain and Gyejok mountain. In addition, the Dongbang stream flowing to the east well illustrates the Pungsu theory of mountain in the back and water in the front. Third, the house is structured in the shape resembling the character 品, divided into 5 areas by hierarchical order in the cross line from all directions. The site, which includes the outdoor yard and the back garden, consists of 5 blocks, 6 yards and 2 gardens. Fourth, the outdoor yard with aesthetical value and anti-fire function, is an ecological garden influenced by Confucianism and Taoism with a pond (BangJiWonDo Type, 方池圓島形) at the center. Fifth, the Sarang yard(舍廊庭) is decorated with terrace garden and flower garden, and the landscaping components such as oddly shaped stone, crane, plum, pine tree, tamarisk tree and flowering plants were used to depict the ideal fairy land and centrally placed tree for metaphysical symbolism. The upper floor of Sarangchae commands distant and medium range view, as well as upwards and downwards. The natural landscape intrudes inside, and at the same time, connects with the outside. Sixth, pine forest over the northern wall and the intentionally developed low hill are one of the traditional landscaping techniques that promotes pleasant residential environment as well as the aesthetics of balanced fullness.