• Journal of the Korean Geotechnical Society
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• v.38 no.4
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• pp.5-20
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• 2022

To analyze the flow and density variations in debris flows, a two-phase finite volume model simplified with momentum equations was constructed in this study. The Hershel-Buckley rheology model was employed in this model to account for the internal and basal friction of debris flows and was utilized to analyze complex topography and entrainments of basal soil beds. In order to numerically solve the debris flow analysis model, a finite volume model with the Harten-Lax-van Leer-Contact method was used to solve the conservation equation for the debris flow interface. Case studies of circular dam failure, non-Newtonian fluid dam failure, and multiple debris flows were analyzed using the proposed model to evaluate shock absorption capacity, numerical isotropy, model accuracy, and mass conservation. The numerical stability and correctness of the debris flow analysis of this analysis model were proven by the analysis results. Additionally, the rate of debris flow with various rheological properties was systematically simulated, and the effect of debris flow rheological properties on behavior was analyzed.

• Korean Journal of Heritage: History & Science
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• v.56 no.4
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• pp.132-158
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• 2023

The five-story and seven-story stone pagodas at Cheongnyangsaji temple site in Gongju are located under the Sambulbong peak of Gyeryongsan mountain, and are known to have been built of the middle in Goryeo dynasty. As the two pagodas in which two types of Baekje stone pagoda coexist in one era, their historical and academic value are recognized. The seven-story pagoda was overturned by robbery in 1944, and as a result, the five-story pagoda was tilted. Although the two pagodas were restored in 1961, structural instability was continuously raised. In this study, measurement data accumulated from May 2021 to March 2022, and seasonal characteristics were reviewed, and the micro behavior of pagodas were analyzed according to temperature and precipitation during the same period. As a result, the micro thermoelastic behavior was repeated according to the daily temperature change in all sensors, and both the slope and the displacement showed microscale behavior. In the inclinometer, moisture containing the surface and inside of the stones repeated expansion and contraction due to temperature change, showing the micro movements. In particular, the upper part of the five-story pagoda moved up to 3.89° to the northwest, and the seven-story pagoda tilted up to 0.078° to the northeast. The maximum displacements were recorded as 0.127 and 0.149 mm in the five-story and the seven-story pagoda, respectively. These values tended to return to the original position at the end of the measurement, but did not recover completely, indicating a state requiring precise monitoring. The result obtained through the study can be used as basic data for the stable conservation of the two stone pagodas. Based on the behavioral characteristics considering various environmental factors should be analyzed, and the preventive conservation through the maintenance of measurement system built this time should be continued.

• Hwankyungkyoyuk
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• v.21 no.1
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• pp.16-30
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• 2008

This study was aimed at finding what effects pro-con discussion classes have on students' environmental decisions and set a series of research questions as follows. First, in a small group discussion, how a student's environmental decision is affected by opinions of other students in the same group. Second, what would be the relations between a students' personal factors including gender, environmental knowledge, attitude, and behavior and their decisions. A decisional experiment was applied to 185 students consisting of 2 girl classes and 4 boy classes of K highschool located in Kongju City, Chungnam. These students were taking 'Ecology and Environment' as one of the few general selective subjects once a week. Decision issue introduced to the experiment was regarding of constructing a wind power station on Baekdu Mountains which is protected by the law. This issue can be characterized as not conflict between conservation and development but conflict between two different types of environment friendly approaches that make students experience more difficult while making a decision. The results of this study an be summarized as follows. First, after taking the class introducing environmental issues and having a debate other students on the issue both within a small group or all classmates together, just less then 30% of the students changed their selections. Second, students were found to be affected by other students' opinion while making his or her own decision. Third, no relationship was found to be statistically considerable between students decisions and their personal factors except of their courses, liberal or science.

• Hwankyungkyoyuk
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• v.23 no.4
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• pp.70-81
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• 2010

The present study aimed to understand high school students' environmental literacy for water and their attitudes toward environment. This study was conducted during the spring of the 2010 academic year with the participation of 123 students from a public international high school located in Seoul. The Environmental Science Literacy for Water test and the Revised New Ecological Paradigm scale were administered, and the data were analyzed by descriptive statistics and content analysis. The high school students in this study put strong emphasis on encouraging others to conserve water resources. This belief, however, was not aligned with self-recognition of their own roles in water supply shortages and other problematic water-use behavior. They also had difficulties in understanding the invisible part of matter transformations in water systems. Nevertheless, they showed favorable attitudes toward environmental conservation. In conclusion, the researchers suggest recognizing our own water problems and narrowing the gap between environmental and scientific knowledge of water and actual attitudes about the environment through curricular incorporation of interdisciplinary environmental science literacy into school science.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.5
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• pp.35-43
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• 2014

The automobile industry requires technological innovations to reduce fuel consumption with the public interest in environmental conservation in recent years. Thus, the hybrid system is applied not only to passenger cars but also commercial vehicles. The purpose of this paper is to develop engine ECU_ILS to develop commercial hybrid vehicles. In order to develop the engine and vehicle, the dynamometer and exhaust gas analyzer is needed. However, a lot of time and cost are required. In contrast, the model-based development environment that can be applied to a variety of test conditions can reduce development time. Therefore, a HILS system environment that can consider the behavior of actual vehicles for evaluation of the control logic, fuel consumption and exhaust gas is required. This engine ECU_ILS system was developed in this study, can analyze parameter such as the fuel injection rate, fuel injection time, fuel consumption and exhaust gas like the actual vehicle test using map data. Also, this system is expected to be able to analyze the characteristic of vehicle behavior and the development of peripheral device in relation to engine and vehicles. This HILS system can be used to develop control strategies of commercial hybrid vehicle systems in the future.

• Korean Journal of Ichthyology
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• v.25 no.3
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• pp.182-184
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• 2013

The 9th Indo-Pacific Fish Conference (IPFC9) was held in Okinawa, Japan from 24th to 28th June 2013. Five hundred and thirty two delegates from 36 countries/regions around the world attended. The Conference took place with a welcome address by Dr. Keiichi Matsuura in the Laguna Garden Hotel next to the Okinawa Convention Center in the evening of 23rd June 2013, one day before the official start of the IPFC9. The winners of the two IPFC9 Bleeker Awards, Jeffrey M. Leis (Ecology) and Gerald R. Allen (Systematics) provided excellent talks on "Change in the early life-history of Indo-Pacific Fishes" and "The center of Indo-Pacific reef fish diversity". A total of 462 papers were presented, including 328 oral and 134 poster presentations. The main themes of IPFC9 included systematics, evolution, zoogeography and phylogeography, biodiversity, ecology, behavior, and conservation. There were 14 symposia, which included topics such as "Top predatory fish in the Indo-Pacific ecosystems", "Fish diversity across environmental extremes", "Ontogeny and systematics of Indo-Pacific fishes", and "Phylogenetics and diversification of the Percomorpha". IPFC10 will be held in Papeete, Tahiti.

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2007.04a
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• pp.176-177
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• 2007

We determined how presence of heterospecific individuals in the vicinity of a focal individual affects the behavior of two critically endangered species of cranes on their wintering grounds at Cheolwon in the Korean Demilitarized Zone(DMZ). The Red-crowned crane, Grus japonensis, is larger than the White-naped crane, Grus vipio, and it dominates the White-naped crane in aggressive interactions. We showed that the dominant species increases foraging activity in the presence of the subordinate species presumably because of scrounging of the food from the subordinate. Because interspecific interactions may affect avian endangerments this behavioral findings should be taken into account when managing winter refuges for the two engendered crane species.

• Journal of Environmental Impact Assessment
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• v.22 no.1
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• pp.1-17
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• 2013

Carbon sequestration on soil is one of the counter measurements against climate change in agricultural sector. Increasing incorporation of organic fertilizer would increase soil organic carbon (SOC) but it could bring high potential of nutrient losses which would result in water quality degradation. In this paper, literature review on soil organic carbon behavior according to agricultural management is presented. The results of field experiment to identify the effect of organic and commercial fertilizer applications on SOC and runoff water quality were also presented. Field experiment confirmed increased SOC and nutrient concentrations in runoff water as application rate of organic fertilizer increase. The potential use of simulation model to develop best agricultural management practice considering carbon sequestration and water quality conservation at the same time is discussed and monitoring and modeling strategies are also suggested to achieve the goal.

• Economic and Environmental Geology
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• v.55 no.5
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• pp.447-463
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• 2022

The lime and clay that used in the construction of the Tomb of King Muryeong and the Royal Tombs in Gongju are auxiliary materials, and are used joint and plaster materials for the wall to play a role of structural support. In this study, the homogeneity between the tombs and material characteristics were interpreted through quantitative analysis of lime and clay. As a result of microtexture and composition analysis, almost the same minerals were identified in each sample groups, and similar characteristics were shown in thermal analysis. Geochemically, it is confirmed that the behavior characteristics are very similar regardless of the tombs. The compositions is also confirmed high homogeneity in the diagrams of CaO-MgO-SiO₂, RO₂-(RO+R₂O) correlations, A-CN-K and A-CNK-FM triangles. Therefore, it is interpreted that the clay used for the construction of the tomb complex was supplied from around area, and the raw materials of lime were produced using shell fragments of oyster family based on mainly composed of calcite. It is interpreted that the raw materials of lime were supplied from middens along the west coast of down the Geumgang river in Korean peninsula, but the consideration of the supply site, needs to be cross-validated through stable isotope analysis, use of carbonate rock and reproduction experiments.

• Economic and Environmental Geology
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• v.56 no.2
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• pp.201-215
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• 2023

In the stone-lined tombs from Cheongyang Rokpyeong-ri site, several stone-lined tombs corresponding to the Three Kingdoms Period, Unified Silla Period and Goryeo Dynasty were excavated. In this study, the stone properties of petrological, mineralogical and geochemical characteristics from 15 stone-lined tombs were analyzed, the rock species and occupation rate were reviewed, also the provenance area was interpreted. There are five types of rocks used as members of the tombs, including black sandstone, greywacke, slate, conglomerate and gneiss. As a result of magnetic susceptibilities, the rocks of the tombs and presumed provenance are all shown in the same range, and the similarity between the tombs and the source area is high in geochemical behavior characteristics. The stone properties of the tombs are the same as the presumed provenance rocks and is distributed within a 500m around the bedrock of the tombs in the excavation site, so it seems that self-sufficiency was possible on the site without a special procurement system. These stones are interpreted to have been constructed through some trimming without any special technique, but some stone tombs have been confirmed to used homogeneous black sandstone at the bottom of the tombs, so it is believed that there were artificial selection of stones.