• The Plant Pathology Journal
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• v.37 no.4
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• pp.396-403
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• 2021

Fire blight disease, caused by Erwinia amylovora, could damage rosaceous plants such as apples, pears, and raspberries. In this study, we designed to understand how E. amylovora affected other bacterial communities on apple rhizosphere; twig and fruit endosphere; and leaf, and fruit episphere. Limited studies on the understanding of the microbial community of apples and changes the community structure by occurrence of the fire blight disease were conducted. As result of these experiments, the infected trees had low species richness and operational taxonomic unit diversity when compared to healthy trees. Rhizospheric bacterial communities were stable regardless of infection. But the communities in endosphere and episphere were significanlty affected by E. amylovora infection. We also found that several metabolic pathways differ significantly between infected and healthy trees. In particular, we observed differences in sugar metabolites. The finding provides that sucrose metabolites are important for colonization of E. amylovora in host tissue. Our results provide fundamental information on the microbial community structures between E. amylovora infected and uninfected trees, which will contribute to developing novel control strategies for the fire blight disease.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.46-47
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• 2013

This study investigates the effect of a grading of aggregate on the properties of concrete. It is a common sense in Korea that the production of coarse aggregate in ready mixed concrete industry excludes particular aggregate size ranged from 5 mm to 13 mm for saving the production cost. This causes a gap grading of the aggregate for concrete, which can lead to the increase of unit water, the development of drying shrinkage-induced crack and the reduction of compressive strength. In this study, conventional aggregate obtained from a ready mixed concrete factory and the aggregate with a modified grading produced in lab. condition were prepared. Results showed that a good grading of aggregate (i.e., the ratio of 5~13 mm and 13~25 mm is 6 to 4) produced in the lab. condition significantly improved the slump and the compressive strength of the concrete.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.3
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• pp.528-550
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• 2024

Warehousing demand prediction is an essential part of the supply chain, providing a fundamental basis for product manufacturing, replenishment, warehouse planning, etc. Existing forecasting methods cannot produce accurate forecasts since warehouse demand is affected by external factors such as holidays and seasons. Some aspects, such as consumer psychology and producer reputation, are challenging to quantify. The data can fluctuate widely or do not show obvious trend cycles. We introduce a new model for warehouse demand prediction called MAGRU, which stands for Multi-layer Attention with GRU. In the model, firstly, we perform the embedding operation on the input sequence to quantify the external influences; after that, we implement an encoder using GRU and the attention mechanism. The hidden state of GRU captures essential time series. In the decoder, we use attention again to select the key hidden states among all-time slices as the data to be fed into the GRU network. Experimental results show that this model has higher accuracy than RNN, LSTM, GRU, Prophet, XGboost, and DARNN. Using mean absolute error (MAE) and symmetric mean absolute percentage error(SMAPE) to evaluate the experimental results, MAGRU's MAE, RMSE, and SMAPE decreased by 7.65%, 10.03%, and 8.87% over GRU-LSTM, the current best model for solving this type of problem.

• Nuclear Engineering and Technology
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• v.55 no.11
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• pp.4181-4190
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• 2023

Nuclear power plants are subjected to various processes during decommissioning, including cutting, decontamination, disposal, and treatment. The cutting of massive bio-shields is a significant step in the decommissioning process. Cutting is performed near the target structure, and during this process, workers are exposed to potential radioactive elements. However, studies considering worker exposure management during such cutting operations are limited. Furthermore, dismantling a nuclear power plant under certain circumstances may result in the unnecessary radiation exposure of workers and an increase in secondary waste generation. In this study, a cutting scenario was formulated considering the bio-shield as a representative structure. The specifications of a standard South Korean radioactive waste disposal drum were used as the basic conditions. Additionally, we explored the hot-to-cold and cold-to-hot methods, with and without the application of polishing during decontamination. For evaluating various scenarios, different cutting time points up to 30 years after permanent shutdown were considered, and cutting speeds of 1-10nullm²/h were applied to account for the variability and uncertainty attributable to the design output and specifications. The obtained results provide fundamental guidelines for establishing cutting methods suitable for large structures.

• Journal of Korean Critical Care Nursing
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• v.17 no.2
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• pp.55-70
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• 2024

Purpose : The demand for skilled critical care nurses and the significant impact of the practice-readiness gap underscore the need for educational programs bridging nursing education and clinical practice. This would ensure safe, high-quality patient care and a stable workforce. This study aimed to explore the educational needs of critical care nurses to develop an essential nursing education program for nursing students, addressing the practice-readiness gap they may encounter as new nurses. Methods : The study espoused a qualitative approach by utilizing focus group interviews conducted in South Korea in April and May 2022. A total of 11 nurses participated in the study. Data were collected from three focus groups, each consisting of three to four nurses from intensive care units. Focus group interviews were conducted using a semi-structured questionnaire. Content analysis was performed on the interview data using thematic analysis. Ethical approval for the study was obtained from the institutional review board. Results : Nursing education programs in intensive care units should prioritize fundamental nursing competencies such as basic nursing and physical examinations. Participants' critical care nursing education needs were categorized into four main themes: holistic nursing competency, advancement of practical education, skilled communication, and systematic critical care nursing education. Conclusion : The study's findings provide valuable insights and guidelines for developing critical and intensive care nursing education programs tailored for nursing students.

• Journal of Wetlands Research
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• v.10 no.1
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• pp.59-68
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• 2008

Three phases of development in construction projects (i.e. pre-development, construction and post construction) diversely effect the environment, hydraulics and ecosystem. Currently, the domestic environmental policy is in control of the various environmental hazards produced after completion of development operations. Nevertheless, with the enforcement of water pollution total amount management system, improving the water quality; also the water and ecosystem preservation law recommends enforcing the sediment management for development operations in order to lessen the negative impacts to the environment. Recently, the country is experiencing difficulties in various development project locations due to insufficiency of interpreting the fundamental data for sediment loss and miscalculation of soil loss unit loads of sediment. This research utilizes data from 2000 to 2005 discussing a total of 1,036 environment impact assessment projects gathered from various ministries and offices namely Ministry of Environment (MOE), Ministry of Agriculture, the Office of Forestry, and Ministry of Construction and Transportation. Moreover, quantity of sediment from high land agriculture reports involving contaminant discharge characteristic investigation previously did concerning old land agriculture and So-Yang lake non-point pollution source management area as well as management measured data from MOE. The findings of this study reveal that the highest soil loss rate occurred from mountain district for pre-development and post construction and sports facility during construction.

• Korean Journal of Construction Engineering and Management
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• v.15 no.6
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• pp.63-70
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• 2014

Deconstruction of the building must be applied firstly in order to improve recycling and reuse of construction wastes. In this study have done a case study for deconstruction of an apartment. All construction waste(CW) which will be generated during deconstruction was examined in each part of the building. Because drawing did not exist in most of the old building, we drew up floor plans of buildings. After analyzing these drawings, estimated quantities of CW. It was measured working time of labor and equipments for deconstruction and general demolition on each building of the apartment. In addition, it was proposed in the volume and weight per unit after analyzing detailed measurement of CW which was generated in the process of deconstruction and traditional demolition. It suggested recovery rate at a site, volume and weight conversion factors, and waste basic unit per area that based on the results of comparative analysis on the amount of CW which is calculated from drawing and generated at a site. These factors will be used fundamental materials for estimating quantities and treatment cost of CW, and scheduling of works.

• Journal of the Korean GEO-environmental Society
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• v.11 no.8
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• pp.33-40
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• 2010

In this study, evaluation of basic unit of non-point pollutant, which is fundamental evaluation of non-point loading, was conducted using both road point and angle of intersection point in Maesong area, West coast highway by utilizing Event Mean Concentrations(EMC). Concentration of pollutants except heavy metals at these two points rapidly decreased in 30 minutes after start of runoff. According to the results of EMC, for both sampling points, it was determined that the concentrations of TSS(Total Suspended Solid), $BOD_5$(Biological Oxygen Demand), and DOC(Dissolved Organic Carbon) were higher than those of wastewater effluent standard in Korea, however, the concentrations of T-N(Total Nitrogen) and T-P(Total Phosphorus) were lower than those of the standard. In terms of heavy metals, Fe, Pb, and Zn showed higher concentrations than others. When compared with the units established by the Ministry of Environment in Korea, the basic units of $BOD_5$ and T-N in this study were lower. On the other hand, when compared with foreign units, Cu, Pb, and Zn showed approximately 10 times higher concentrations. It was estimated that a long term monitoring should be conducted for obtaining additional data and more reliable basic units for the non-point pollutnats based on the results from this study.

• International Journal of Highway Engineering
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• v.11 no.3
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• pp.41-49
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• 2009

Cement concrete pavement has become more common in Korean highway systems. However, as its service period increases, there are some technical problems occurs and no clear solution is available primarily due to the lack of active researches. This research, hence, aims to develop a new mix proportion that may provide better strength and durability with extended service life. Based on a variety of literature reviews, the experimental variables were determined as unit cement content, S/a ratio and W/C ratio. From the experimental works, it is recommended to increase the unit cement content up to 375kg/$m^3$, 400kg/$m^3$ and 425kg/$m^3$. The target slump and air content were set 40mm and 5%, respectively. The maximum size of coarse aggregate was decided to be 25mm because of the easiness of supply in the field. The reduction of W/C ratio was necessarily required and decreased to 0.4 which was proven not to cause any mixing problem with the increased unit cement contents along with polycarbon-based high range water reducing agent. In addition, it was known that the S/a ratio could be reduced to 0.34. The lowered S/a might be possible because of the increased cement paste and hence increased cohesiveness and workability.

• Journal of The Korean Association For Science Education
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• v.20 no.4
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• pp.505-509
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• 2000

The kinetic structure of the content of instructions at the unit of 'heart and circulation' in "the common science", which was respectively given by two teachers majored in biology and two teachers majored in earth science was investigated. Concerning of the mean of the fundamental coefficient (B1), the mean of weighted coefficients (B2) and the progression of instruction (P), T4 (B1, 0.14; B2, 0.82; P; 0.86) teacher showed relatively lower kinetic structure and faster progression than those of the others. The other teachers showed a different level of the kinetic structure and progression: T1(B1, 0.21; B2, 0.86; P; 0.79), T2 (B1, 0.02; B2, 0.85; P; 0.80), and T3 (B1, 0.22; B2, 0.83; P; 0.78). T1 teacher who showed the largest total frequency of verbal elements, the great number of sorts of verbal elements and secondary span, had a higher level of the kinetic structure, but T4 teacher showed the lowest level of total frequency of verbal elements, the great number of sorts of verbal elements and secondary span. The main reason why T4 teacher's instruction achieved a lower level of kinetic structure was estimated that he neglected to reorganize teaching materials and he showed a small number of discourse units. In addition, the unit of 'heart and circulation' was less related to T4 teacher's major and T4 teacher had a shorter teaching experience than those of the others. T4 teacher also took charge of only one class, and this did not allow to instruct repeatedly.