• Progress in Medical Physics
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• v.26 no.4
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• pp.280-285
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• 2015

In radiation therapy fields, a brachytherapy is a treatment that kills lesion of cells by inserting a radioisotope that keeps emitting radiation into the body. We currently verify the consistency of radiation treatment plan and dose distribution through film/screen system (F/S system), provide therapy after checking dose. When we check dose distribution, F/S systems have radiation signal distortion because there is low resolution by penumbra depending on the condition of film developed. In this study, We fabricated a $HgI_2$ Semiconductor radiation sensor for base study in order that we verify the real dose distribution weather it's same as plans or not in brachytherapy. Also, we attempt to evaluate the feasibility of QA system by utilizing and evaluating the sensor to brachytherapy source. As shown in the result of detected signal with various source-to-detector distance (SDD), we quantitatively verified the real range of treatment which is also equivalent to treatment plans because only the low signal estimated as scatters was measured beyond the range of treatment. And the result of experiment that we access reproducibility on the same condition of ${\gamma}$-ray, we have made sure that the CV (coefficient of variation) is within 1.5 percent so we consider that the $HgI_2$ sensor is available at QA of brachytherapy based on the result.

• The Journal of the Petrological Society of Korea
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• v.21 no.1
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• pp.1-12
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• 2012

The Baegdusan volcano is one of the most active volcanoes in northeastern Asia, and the 10th century eruption was the most voluminous eruption in the world in recent 2,000 years. During the period from 2002 to 2005, volcanic earthquakes and abnormal surface distortions by suspected subsurface magma intrusion beneath the volcano were observed in the Baegdusan area. Seismic activity has gradually increased with earthquake swarms during 2002-2003 and hundreds of seismic event in a day, especially annual peak of 2,100 in 2003. Then the number of seismic activity has declined since 2006 to the background level in 1999-2001. According to the typical frequency of volcanic earthquakes in the Baegdusan volcano, the frequency distribution of typical volcanic earthquakes between 2002 and 2005 indicates that all the main frequency of the earthquakes basically falls down less than 5 Hz and 5-10 Hz. These events are all the VT-B and LP events caused by the shallow localized fracture and intrusion of magma. The horizontal displacement measurement by GPS during the period from 2000 to 2007 of the Baegdusan stratovolcano area indicates that an inflated process has been centered at the summit caldera since 2002. The displacement between 2002 and 2003 reached at a maximum value of 4 cm. After 2003, the deformation rate of the volcano continued to decrease with unusual variation during the period from 2006 to 2007. After 2003 the vertical displacement uplift rate falls down gradually but still keeps in an uplift trend in northern slope. It is generally believed that when $^3He/^4He(R)$ in a gas sample from a hot spring exceeds $^3He/^4He(R)$ in the atmosphere, it can be concluded that mantle-source. And temperatures of hot springs are rising steadily to $83^{\circ}C$. It is unrest signals at the Baegdusan, which is potentially active. The Baegdusan volcano is now in unrest status, there is eruption threat in the near future. Intensified monitoring and emergency response plan for volcanic risk mitigation are urgent for the volcano.

• Journal of Wetlands Research
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• v.19 no.1
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• pp.30-36
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• 2017

SS(Suspended Solid) concentration by soil erosion into river at normal and flood season should be measured. However, to present the variation of SS due to various development project such as EIA(Environmental Impact Assessment), River Master Plan, and so on, it is necessary to estimate not measure SS, but there are not exist how to estimate SS. In the present study, therefore, we propose the hydrologic method of estimating SS concentration using the results of particular frequency flood discharge and sediment discharge by RUSLE method. SS consists of silty and clay soil and colloid particle etc. However, in the present study, silty and clay soils of sediment discharge except send set up SS standards. The flow discharge to estimate SS concentration are 1~2 years for normal season, 30~100 years for flood season. Meanwhile, analysis software for probable rainfall uses Fard2006, probable rainfalls under 2-year frequency are estimated using rainfall data and frequency factor of Gumbel distribution. The results of estimating SS concentration using runoff volume by sediment and flow discharges of silty and cray soils as above method show that reliable level of SS concentration is considered in predevelopment of natural condition and under development of barren condition. Especially, SS concentration takes notice that the value of sediment discharge makes a huge difference according to channel slope, it was confirmed that the value obtained by dividing the SS concentration by the channel slope is relatively constant even though the topographical factors are different. Therefore, if the present study will be proceeded for various watersheds, it will be developed as estimation method of SS concentration.

• Korean Journal of Ecology and Environment
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• v.39 no.2 s.116
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• pp.271-283
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• 2006

A systematic water quality survey was conducted in August, 2005 for a drinking water supply reservoir (the Jeolgol reseuoir located in an island), which is at an early stage of impoundment, to investigate the causes of water color deterioration of the reservoir and the clogging of filter beds of a water treatment plant. The reservoir shape was simple and its average depth was 5.5 m, increasing from upreservoir toward the downreservoir end near the dam. Dissolved oxygen (DO) and chloropllyll-a (chi-a) showed a large variation while water temperature had a smaller range. Transparency ranged from 0.6 to 0.9 m (average 0.7 m). The average value of turbidity was 9.3 NTU, ranging from 8.0 ${\sim}$ 12.1 NTU. The transparency and the turbidity appear to be affected by a combination of biological and non-biological factors. The poor transparency was explained by an increase of inorganic colloids and algal bloom in the reservoir. The blockage of the filter bed was attributed to the oversupply of phytoplanktons from the reservoir. The range and the average concentration of chi-a within the reservoir were 31.6 ${\sim}$ 258.9 ${\mu}g\;L^{-1}$, 123.6 ${\mu}g\;L^{-1}$ for the upper layer, and 17.0 ${\sim}$ 37.4 ${\mu}g\;L^{-1}$, 26.5 ${\mu}g\;L^{-1}$ for the bottom layer, respectively. A predominant species contributing the algal bloom was Dinophyceae, Peridinium bipes f. occultatum. The distribution of Peridinium spp. was correlated with chi-a concentrations. The standing crop of phytoplankton was highest in the upreservoir with $8.5\;{\times}\;103\;cells\;mL^{-1}$ and it decreased toward the downresevoir. Synedra of Bacillariophyceae and Microcystis aeruginosa of Cyanophyceae appeared to contribute to the algal bloom, although they are not dominated. It is mostly likely that sloped farmlands located in the watershed of the reservoir caused water quality problems because they may contain a significant amount of the nutrients originated from fertilizers. In addition, the aerators installed in the reservoir and a shortage of the inflowing water may be related to the poor water quality. A long-term monitoring and an integrated management plan for the water quality of the watersheds and the reservoir may be required to improve the water quality of the reservoir.

• Korean Journal of Environment and Ecology
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• v.26 no.4
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• pp.537-549
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• 2012

The purpose of this study was to provide data for the basic research to found the effective conservation and management plan for the Hamyangsangrim designated as Natural Monument No. 154 and surround areas by analyzing the ecological characteristics such as landuse and actual vegetation, plant community structure, soil chemical property and also to identify the tendency of the ecosystem changes through comparison with past studies. According to analysis the results, the landuse and actual vegetation of survey site was classified as 8 types which were forest, artificial greenspace, plaza and open-space, bare ground and the pavement, water bodies, facilities, agricultural land and etc.. It was also categorized as 38 types according to detailed characteristic. 15 kinds of forest vegetation community types comprising silva were classified among them. The changes of actual vegetation showed little variation that the Quercus serrata-Carpinus tschonoskii forest was the most widely distributed in 2003(forest area ratio is 48.3%) and 2010(forest area ratio is 48.1%), whereas, the Quercus serrata forest declined a more dramatic from 11.6% to 23.2%. The Quercus serrata-Carpinus tschonoskii forest increased sharply(11.6% ${\rightarrow}$ 23.2%) and also the Quercus serrata-Zelkova serrata forest increased steadily(2.2% ${\rightarrow}$ 7.9%). The agricultural land around forest was transformed into artificial green zone. Moreover, water bodies, bare ground and the pavement of areas have increased. In addition, the urbanized area has decreased because the damaged areas inside forest have been restored to the woodlands. According to the result of typical 6 types vegetation communities change, the middle layer trees grew up to the canopy layer trees and was formed the canopy layer structure. The middle layer trees expanded their forces widely. Also new species appeared. And the shrub individuals also more dramatically increased due to the growth of shrubs. The force of Quercus serrata declined as well. However the force of Carpinus tschonoskii and Zelkova serrata expanded and increased in the forest. It must be the result of the ecological vegetation succession and environmentally soundly health recovery by influence of the projects of forest surrounding environment improvement and limitation of access to forest have managed and maintained since 2003. Those sorts of changes seems to be going to develop continuously. In the future Carpinus tschonoskii and Zelkova serrata will not be only codominant in the canopy layer but also Carpinus Tschonoskii, Zelkova serrata, Meliosma myriantha, Sapium japonicum. Styrax obassia and Acer pseudo-sieboldianum will be codominant in the middle layer. As a result, the forest's codominance species are going to be changed such like that.

• Archives of design research
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• v.12 no.4
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• pp.231-241
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• 1999

This study propose to analyze the design method and the form elements of museums, of works by Richard Meier, and through the analysis, spacial characteristics of museums will be understood. The museum works of Richard Meier, as an exhibition space, not only display the art works efficiently, but they also offer visitors the opportunity to experience the art of architecture, as a cultural space. Richard Meier, when working on the projects, has utilized the design methods and the architectural language, learned from Mies van der Rohe and Le Corbusier, resourcefully. Having the structural grid as basis, the rational rectangular forms were intended for exhibition space, while the circular and partial circular forms of geometry were utilized in formative space. This was able to maintain the balance between functional and formative space. In the museums of his works, the ramp and the glass wall separated from the structure become very important means of expression. The ramps, not only make people to enjoy the interior and exterior of museum, but also able them to see the works of art from different distances and angles repeatedly and the large glass wall reveals the various shapes of interior to exterior. In comparing with the design method and language of two masters mentioned, the design principles and elements, developed by Meier were applied to the site plans, exhibition space planning and elevations to manifest its originality. The design concept, derived from the urban fabric and historical buildings around, gave harmony to the museum with its surroundings, and employing the deformed axis brought variation and the effect of diversion to the site plan. The exhibition space is much vitalized by the well arrangement of various exhibition fixtures in the museum. The exhibion fixtures, which the partitions, shelves, miches, and stages were put together in flexibility, play multiple roles as partitions dividing spaces, as furniture displaying art works, and as elements creating forms. The systematically arranged fixtures, also produce several visual axes and centers, which have visitors appreciate the works of art in various perspectives, hence create a unique environment.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.28 no.2
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• pp.109-117
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• 2010

This study conducts a case analysis based on the Olympic Forest Park in Beijing, which is specially designed for the 2008 Beijing Olympic Games. The construction of the Olympic Forest Park not only comprises the design philosophy of city parks and forest parks, but also applies Chinese traditional design elements. This study, first, researches on the design concepts of city parks in the context of traditional landscape architecture elements from both physical and cultural perspectives. The author studies the related materials including the"General Introduction of the Beijing Olympic Forest Park Landscape Plan", and employs the approaches of site investigation and user survey and interview, to analyze the cognition and preference degree of the various traditional design elements displayed in the Olympic Forest Park. To quantize the survey data on the Olympic Forest Park, this study uses the spss(v17.0) software to run a frequency analysis and presents detailed demographic, frequencies and means analyses. The author then reaches the conclusion on the preference degree of the various Chinese traditional design elements in the Olympic Forest Park. According to the analysis result, the elements that appear with the highest frequencies are mountains and waters, traditional garden plants and artistic conception. The most favorable elements are in sequence traditional garden architecture, traditional garden philosophical thinking and artistic conception. The Olympic Forest Park in Beijing is constructed on the basis of multiple design elements, comprising Chinese traditional design elements and the historical axis. As an exemplification of contemporary city park that reflects the variation of age and development of society, the Olympic Forest Park offers the reference for the selection of traditional design elements in the future schemes of city parks. However, due to the difficulty in gathering materials about the Forest Park and the limitations on the location and time constrain of the survey, there exists lack of sufficiency that could be improved in the future.

• Journal of vocational education research
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• v.30 no.4
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• pp.23-49
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• 2011

Faculty performance evaluation system has been settled down as an uncomfortable but unavoidable system, and it is one of the most important factors to grow the college competitiveness up. In this study, we selected and surveyed faculty evaluation models of several universities and colleges in Korea, and analyzed by comparing each evaluation areas of educational achievement, college-industry collaboration, research, and service. We also identified the properties of the current faculty evaluation models of the junior colleges, and derived several problems from these models such as an imitation of four-year university model, a disorders of job evaluation with respect to the attributes of classified jobs, a large variation of individual item weights, and an insufficient reflection of major characteristics. Based on these surveys and analysis, an improved faculty evaluation model for the junior college is proposed in this study. This model proposed four basic areas-educational achievement, college-industry collaboration, research, and service by considering the importance of the college-industry collaboration in the junior college-as well as the team evaluation area. Weights of the SCI-class paper was selected as a criterion for the arrangement of objective comparison of each evaluation items. We showed the integration method of several different evaluation model with respect to the attributes of classified jobs of each faculties, and evaluation plan of variational characteristics according to the majors of individuals in this model. Finally, we introduced an area fail and rating system to operate efficiently the proposed faculty evaluation model.

• Journal of Korea Water Resources Association
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• v.55 no.8
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• pp.603-611
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• 2022

In urban areas, the impermeable area continues to increase due to urbanization, which interferes with the surface penetrating and infiltrating of rainwater, causing most rainwater runoff to the surface, deepening the distortion of water circulation. Distortion of water circulation affects not only flood disasters caused by rainfall and runoff, but also various aspects such as dry stream phenomenon, deterioration of water quality, and destruction of ecosystem balance, and the Ministry of Environment strongly recommends the use of Low Impact development (LID) techniques. In order to apply the LID technique, it is necessary to set a rainwater management target to handle the increase in outflow after the development of the target site, and the current standard sets the rainwater management target using the 10-year daily rainfall. In this study, the difference from the current standards was analyzed through statistical analysis and classification of independent rainfall ideas using inter-event time definition (IETD) in setting the target amount of rainwater management to improve water circulation. Using 30-year rainfall data from 1991 to 2020, methods such as autocorrelation coefficient (AC) analysis, variation coefficient (VC) analysis, and annual average number of rainfall event (NRE) analysis were applied, and IETD was selected according to the target rainfall period. The more samples the population had, the more IETD tended to increase. In addition, by analyzing the duration and time distribution of independent rainfall according to the IETD, a plan was proposed to calculate the standard design rainfall according to the rainwater management target amount. Therefore, it is expected that it will be possible to set an improved rainwater management target amount if sufficient samples of independent rainfall ideas are used through the selection of IETD as in this study.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.2
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• pp.1-19
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• 2023

In Korea, excessive vegetation in rivers made up of sand and gravel is emerging as a nationwide problem, which is attributed to increased spring precipitation and decreased annual precipitation. Therefore, this study was conducted for the purpose of identifying the effect of changes in precipitation patterns on river vegetation in Namcheon, Gyeongju, and analyzing the area of vegetation and ecological characteristics. As a result of the study, the amount of monthly precipitation in the summer of Namcheon decreased after 2007, and the area of vegetation increased continuously compared to the area of the sandbank. The proportion of naturalized plants increased steadily when precipitation continued to a level that did not cause flooding, but the area occupied by naturalized plants was small. Also, when the water level is maintained, the species diversity is low due to the dominance of a single species, and the dominant species was mainly native plants. Dominance of native plants inhibited the growth of naturalized plants, but the vegetation area increased even more. Therefore, it is necessary to manage the spread of vegetation itself rather than the division of native plants and naturalized plants in order to eliminate the active growth and prosperity of river vegetation. High water levels and continuous flooding caused by torrential rains in summer disturbed the plant communities, and vegetation formed afterwards was mainly native plants. Such flooding in river ecosystems is a positive factor for the emergence of native plants and over-formed vegetation communities, so it should be considered when establishing a vegetation management plan.