• Journal of Korean Society of Forest Science
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• v.112 no.4
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• pp.523-529
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• 2023

The aim of this study was to analyze the potential for timber harvesting in the Hongchoen Garisan Leading Forest Management Complex in the national forests, and to suggest an optimal target yield for sustainable timber harvesting. The potential for timber harvesting was assessed by analyzing the area available for timber harvesting using GIS spatial analysis, but excluding areas with a slope of more than 40° (topographical constraints), areas within 30 m on both sides of streams (environmental constraints), and areas more than 300 m away from forest roads (technical constraints). The analysis identified 3,298 ha (49%) of the total complex area of 6,679 ha as available for timber harvesting, yielding a potential harvesting volume of 608,613 m³. In the case of coniferous plantations, the potential harvesting volume was 409,721 m³, which was a very high level that accounted for 67.3% of the total. We also conducted an optimization analysis to minimize the differences in area between age classes, while maintaining sustainable timber harvesting for the next 50 years. An annual average of 41.9 ha (7,988 m³) was determined to be the optimal timber yield, and in this case, it was possible to convert the age class structure to a more stable structure after 50 years.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.15 no.3
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• pp.133-139
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• 2010

Marine algal flora and community structure were investigated at four sites in Kijang area on the southern east coast of Korea in August 2006 and August 2009, respectively. A total of 54 seaweeds including 6 green, 10 brown, 38 red were collected and identified. Of 54 seaweeds, 35 species were found throughout the survey period. Mean biomass in wet weight was from $616.0\;g\;m^{-2}$ to $1,462.4\;g\;m^{-2}$2 in 2006, and $354.8\;g\;m^{-2}$ to $965.6\;g\;m^{-2}$ in 2009. Maximum biomass was recorded at Mundong site, and minimum was recorded at Seoam (2006) and Dongbaek (2009) sites. The flora investigated (2006, 2009) could be classified into six functional groups such as coarsely branched form (58.7%, 58.1%), thick leathery form (10.9%, 11.6%), filamentous form (13.0%, 9.3%), crustose form (6.5%, 9.3%), sheet form (6.5%, 7.0%) and jointed calcareous form (4.3%, 4.7%) during survey period. The R/P, C/P and (R+C)/P values reflecting flora characteristics were 4.00, 0.75 and 4.75 at 2006, and 5.17, 1.00 and 6.17 at 2009, respectively. Therefore, the number of marine algae species and biomass in Kijang area were similar when they were comparing with the previous data. It suggest that any changes of seaweed diversity have not been observed in Kijang coastal area before and after the anthropogenic construction between 2006 and 2009.

• Journal of The Korean Association For Science Education
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• v.29 no.1
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• pp.22-42
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• 2009

The purpose of the case study is to understand changes in the teaching practices of two secondary science teachers during the span of their careers. To investigate changes in teaching practices, this study focuses on changes in the science teachers' practical principles based on Elbaz's practical knowledge. The biographical approach was adopted because teachers' voices are a valuable source to understand their professional development. In-depth interviews and classroom observations were conducted for two science teachers with seven years' and ten years' teaching experience. The major findings are as follows: First, participants' teaching practices changed through interaction with three factors, critical experiences that have stirred changes in teaching practice, teacher's reflection on teaching, and various experiences to make specific teaching practice changes. Second, three different change aspects of practical principles were revealed; reinforcement of existing practical principles, replacing old practical principles with new one, and generation of new practical principles.

• Journal of The Korean Association For Science Education
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• v.27 no.9
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• pp.818-831
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• 2007

Recognizing the importance of abductive inquiry in Earth science, some theoretical approaches that deploy abduction have been researched. And, it is necessary that the abductive inquiry in a geological field excursion as a vivid locale of Earth science inquiry should be researched. We developed a geological field trip based on the abductive learning model, and investigated students' abductive inference, thinking strategies used in those inferences, and the impact of a teacher's pedagogical intervention on students' abductive inference. Results showed that students, during the field excursion, could accomplish abductive inference about rock identification, process of different rock generation, joints generation in metamorpa?ic rocks, and terrains at the field trip area. They also used various thinking strategies in finding appropriate rules to construe the facts observed at outcrops. This means that it is significant for the enhancement of abductive reasoning skills that students experience such inquiries as scientists do. In addition, a teacher's pedagogical interventions didn't ensure the content of students' inference while they helped students perform abductive reasoning and guided their use of specific thinking strategies. Students had found reasoning rules to explain the 01: served facts from their wrong prior knowledge. Therefore, during a geological field excursion, teachers need to provide students with proper background knowledge and information in order that students can reason rues for persuasive abductive inference, and construe the geological features of the field trip area by the establishment of appropriate hypotheses.

• Journal of the Korean Institute of Landscape Architecture
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• v.52 no.2
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• pp.1-20
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• 2024

The present study was conducted to assess the adequacy of landscaping plants in city streams by investigating the species and growth status of landscaping plants, taking Godeokcheon in Seoul Metropolitan City as an example. The stream structure related to the planting ground and the impact of flood damage were analyzed. The adequacy of the planting species was analyzed based on the native species and moist land-inhabiting plants presented in the preceding study results. The adequacy, depending on the planting location and planting form, was analyzed using the growth states of adaptive and nonadaptive species by river topography. The planting location of those along the waterfront was the best, followed by the plants on waterside hills and embankment slopes. It is thought that the adaptability of dryland-inhabiting plants increased as the soil dried due to the impervious pavement of surrounding bikeways and trails. The species adequate for embankment slopes are thought to be native species and dryland-inhabiting plants. It is thought that, for waterside hills, the planting rate of wetland-inhabiting plants should be increased, and for waterfronts, the planting rate of dryland-inhabiting plants should be decreased. As for the planting form, the growth state was the best when mixed species were planted and the worst when other plants appeared. For city streams, the planting rates of native species and wetland-inhabiting plants should be increased, and adequate plant species for each location should be selected.

• Journal of the Korean Association of Geographic Information Studies
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• v.27 no.1
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• pp.115-127
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• 2024

This research aimed to construct models with various structures based on the Transformer module and to perform land cover classification, thereby examining the applicability of the Transformer module. For the classification of land cover, the Unet model, which has a CNN structure, was selected as the base model, and a total of four deep learning models were constructed by combining both the encoder and decoder parts with the Transformer module. During the training process of the deep learning models, the training was repeated 10 times under the same conditions to evaluate the generalization performance. The evaluation of the classification accuracy of the deep learning models showed that the Model D, which utilized the Transformer module in both the encoder and decoder structures, achieved the highest overall accuracy with an average of approximately 89.4% and a Kappa coefficient average of about 73.2%. In terms of training time, models based on CNN were the most efficient. however, the use of Transformer-based models resulted in an average improvement of 0.5% in classification accuracy based on the Kappa coefficient. It is considered necessary to refine the model by considering various variables such as adjusting hyperparameters and image patch sizes during the integration process with CNN models. A common issue identified in all models during the land cover classification process was the difficulty in detecting small-scale objects. To improve this misclassification phenomenon, it is deemed necessary to explore the use of high-resolution input data and integrate multidimensional data that includes terrain and texture information.

• Korean Journal of Agricultural and Forest Meteorology
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• v.26 no.3
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• pp.209-218
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• 2024

The National Institute of Agricultural Sciences (NAS) operates in-house long-range climate forecasting system to support the agricultural use of climate forecast data. This system, developed through collaborative research with Pusan National University, is based on the PNU/RDA Coupled General Circulation Model (CGCM) and includes the regional climate model WRF (Weather Research and Forecasting). It generates detailed climate forecast data for periods ranging from 1 to 6 months, covering 20 key variables such as daily maximum, minimum, and average temperatures, precipitation, and agricultural meteorological elements like solar radiation, soil moisture, and ground temperature-factors essential for agricultural forecasting. The data are provided at a daily temporal resolution with a spatial resolution of a 5km grid, which can be used in point form (interpolated) or averaged across administrative regions. The system's seasonal temperature and precipitation forecasts align closely with observed climatological data, accurately reflecting spatial and topographical influences, confirming its reliability. These long-range forecasts from NAS are expected to offer valuable insights for agricultural planning and decision-making. The detailed forecast data can be accessed through the Climate Change Assessment Division of NAS.

• Journal of the Korean Institute of Landscape Architecture
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• v.52 no.4
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• pp.1-17
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• 2024

This study analyzed the behaviors and satisfaction of park users in nine parks representing first and second-generation new towns, aiming to propose directions for planning new town parks. According to the analysis, park users in new towns mainly visit parks for purposes such as relaxation, strolling, and exercise, often with family, alone, or with friends. They typically spend 1-2 hours in the park and mostly access it on foot. Additionally, satisfaction with park accessibility is high, particularly among pedestrians. Satisfaction survey results indicate that pedestrian pathways, trees and vegetation, water features, rest areas, and cultural facilities have the greatest impact on overall park satisfaction. Playgrounds and sports facilities show relatively lower satisfaction levels, indicating a need for improvement. Furthermore, according to NPS analysis, park users are highly willing to recommend parks, especially with Gwanggyo Lake Park and Dongtan Central Park receiving high recommendation scores. IPA analysis shows that pathways and vegetation are perceived as highly important and satisfactory, while playgrounds and sports facilities are categorized as areas needing improvement. Thus, there is a need to consider improvement strategies for each. Additionally, identifying park users' grievances can lead to creating a better park environment. Finally, concerning the planning direction for new town parks, linear-shaped parks facilitating walking are preferred, with parks preserving natural terrain and forests deemed the most desirable. Based on these results, future city parks, including those in the third-generation new towns, should harmonize with nature and prioritize pedestrian access.

• Journal of Korean Society of Forest Science
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• v.113 no.3
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• pp.271-281
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• 2024

The purpose of this study is to establish baseline data on the habitat status of Dracocephalum argunense Fisch. ex Link by identifying its vegetation structure and correlating environmental factors. A total of 9 vegetation plots (10 m×10 m) were surveyed. Cluster analysis revealed a total of three clusters: Quercus aliena (Group 1), Pinus thunbergii-Rubus parvilolius (Group 2), and Indigofera kirilowii-Zanthoxylum piperitum (Group 3). The importance value of D. argunense was the highest in Group 2, with a value of 6.19. Diversity analysis indicated a range of 2.747-3.166, but differences among the groups was not statistically significant (p>0.05). In the areas surrounding sedimentary rock zones, invasive plants were identified as indicator species, emphasizing the need for monitoring invasive species in the future. Although D. argunense exhibits good adaptability to moisture and atmospheric conditions due to its diverse habitats (forest and coast), there is a risk of decline due to interspecific competition and human activities, as analyzed in this study.

• Journal of Korean Society of Forest Science
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• v.113 no.3
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• pp.349-360
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• 2024

This study aimed to analyze the main forest environmental factors affecting the discernment of slow-moving landslide-prone areas in the Republic of Korea, based on data from a detailed landslide survey conducted from 2019 to 2021. Field survey data from 256 sites were collected covering 29 forest environmental factors in seven categories, including geology, soil, and topography. The analysis was conducted using the Random Forest model (AUC = 0.910) and XGBoost model (Accuracy = 0.808, Kappa = 0.594, F1 - measure = 0.494), which were evaluated as having high classification accuracy during the machine learning model development process. Consequently, factors with a high mean decrease Gini (MDG), representing classification importance, were identified as the presence of cracks (average MDG of both models: 22.1), peak elevation (14.8), and the presence of steps (7.0), indicating that these were significant factors in determining slow-moving landslide-prone areas. The presence of cracks and steps aligned well with the characteristics of slow-moving landslides, suggesting that their importance should be emphasized in future detailed landslide surveys. However, the influence of the peak elevation was considered somewhat overestimated due to the characteristics of the input data used in the analysis. These findings are expected to further improve the accuracy and efficiency of final judgments in detailed landslide surveys.