• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.4
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• pp.559-569
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• 2022

Infrastructure engineering is a field that supports construction (assembly) as a representative industry that creates high added value and jobs by combining science and technology with knowledge, though its importance is underestimated. According to a report from the Ministry of Land, Infrastructure and Transport (Korea), the value-added rate (65.3%) of the engineering industry and the employment inducement coefficient (14 employees per billion won) are three times higher than in manufacturing. In particular,the forward value chain (such as project management and basic design) accounts for less than 10~15% of the total project cost but determines the overall price and quality of the infrastructure facilities. In this study, a work break-down system, design support module and database development method for road design projects for design platform development is presented. Based on the presented development method, a cloud-based infrastructure design platform's prototype is developed. The developed infrastructure engineering platform is expected to provide a web-based design work environment without time/space restrictions and greatly contribute to winning overseas business orders and securing competitiveness.

• Korean Journal of Remote Sensing
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• v.38 no.1
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• pp.111-126
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• 2022

Land use and land cover (LULC) mapping is an important factor in geospatial analysis. Although highly precise ground-based LULC monitoring is possible, it is time consuming and costly. Conversely, because the synthetic aperture radar (SAR) sensor is an all-weather sensor with high resolution, it could replace field-based LULC monitoring systems with low cost and less time requirement. Thus, LULC is one of the major areas in SAR applications. We developed a LULC model using only KOMPSAT-5 single co-polarized data and digital elevation model (DEM) data. Twelve HH-polarized images and 18 VV-polarized images were collected, and two HH-polarized images and four VV-polarized images were selected for the model testing. To train the LULC model, we applied the conditional generative adversarial network (cGAN) method. We used U-Net combined with the residual unit (ResUNet) model to generate the cGAN method. When analyzing the training history at 1732 epochs, the ResUNet model showed a maximum overall accuracy (OA) of 93.89 and a Kappa coefficient of 0.91. The model exhibited high performance in the test datasets with an OA greater than 90. The model accurately distinguished water body areas and showed lower accuracy in wetlands than in the other LULC types. The effect of the DEM on the accuracy of LULC was analyzed. When assessing the accuracy with respect to the incidence angle, owing to the radar shadow caused by the side-looking system of the SAR sensor, the OA tended to decrease as the incidence angle increased. This study is the first to use only KOMPSAT-5 single co-polarized data and deep learning methods to demonstrate the possibility of high-performance LULC monitoring. This study contributes to Earth surface monitoring and the development of deep learning approaches using the KOMPSAT-5 data.

• Journal of Korea Society of Industrial Information Systems
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• v.27 no.5
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• pp.37-48
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• 2022

With development of Digital Technology, social issues are communicated through digital-based platform such as SNS and form public opinion. This study attempted to analyze big data from Twitter, a world-renowned social network service, and find out the public opinion. After collecting Twitter data based on 14 keywords for 1 year in 2021, analyzed the term-frequency and relationship among keyword documents with pearson correlation coefficient using Data-mining Technology. Furthermore, the 6 main topics that on the center of information security field in 2021 were derived through topic modeling using the LDA(Latent Dirichlet Allocation) technique. These results are expected to be used as basic data especially finding key agenda when establishing strategies for the next step related industries or establishing government policies.

• Wind and Structures
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• v.34 no.1
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• pp.81-90
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• 2022

To better understand the vortex-induced vibration (VIV) characteristics of a 5:1 rectangular cylinder, the distribution of aerodynamic force and the non-dimensional power spectral density (PSD) of fluctuating pressure on the side surface were studied in different VIV development stages, and their differences in the stationary state and vibration stages were analyzed. The spanwise and streamwise correlations of surface pressures were studied, and the flow field structure partitions on the side surface were defined based on the streamwise correlation analysis. The results show that the variation tendencies of mean and root mean square (RMS) pressure coefficients are similar in different VIV development stages. The RMS values during amplitude growth are larger than those at peak amplitude, and the smallest RMS values are observed in the stationary state. The spanwise correlation coefficients of aerodynamic lifts increase with increase of the peak amplitude. However, for the lock-in region, the maximum spanwise correlation coefficient for aerodynamic lifts occurs in the VIV rising stage rather than in the peak amplitude stage, probably due to the interaction of vortex shedding force (VSF) and self-excited force (SEF). The streamwise correlation results show that the demarcation point positions between the recirculation region and the main vortex region remain almost constant in different VIV development stages, and the reattachment points gradually move to the tailing edge with increasing amplitude. This study provides a reference to estimate the demarcation point and reattachment point positions through streamwise correlation and phase angle analysis from wind tunnel tests.

• Journal of the Korea Convergence Society
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• v.12 no.4
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• pp.87-94
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• 2021

While the shielding substances of radiation shields in medical institutions are beginning to be replaced by environmentally friendly materials, radiation protection according to the shielding properties of environmentally friendly substances is becoming an important factor rather than the existing lead shielding properties. Tungsten and barium sulfate are representative shielding materials similar to lead, and are made in sheets or fiber form with eco-friendly materials. Ytterbium is an impermeable material used as a fluorine compound in the dental radiation field. This study aims to evaluate the shielding performance in the x-ray shielding area by comparing the shielding properties of ytterbium by energy band and that of existing eco-friendly materials. When three types of shielding sheets were fabricated and tested under the same process conditions, the shielding performance of the medical radiation area was about 5 % difference from tungsten. Furthermore, shielding performance was superior to barium sulfate. In the cross-sectional structure of the shielding sheet, there was a disadvantage that the arrangement of particles was not uniform. Ytterbium oxide showed sufficient potential as a medical radiation shielding material, and it is thought that it can improve the shielding performance by controlling the particle arrangement structure and particle size.

• Journal of the Korea Convergence Society
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• v.13 no.5
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• pp.413-424
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• 2022

The purpose of this study was attempted to determine the effect of nursing professionalism and self-leadership on long-term work intentions for graduated nursing students. The subjects of this study were 217 graduated nursing students located in W city, and a structured questionnaire was used for the data collection period from November 29 to December 3, 2021. For data analysis, frequency, t-test, one-way ANOVA, Scheffe, Pearson's correlation coefficient, multiple regression using SAS 9.4 program. As a result of the study, the biggest influence factors on the long-term work intention of graduated nursing students were nursing professionalism and major satisfaction, followed by career planning, and explanatory power was 34.3%. Based on the results of this study, it is necessary to develop and operate various programs in the field of nursing education in order to improve the long-term intention of nursing students in graduation year. However, this study is meaningful in that it provided basic data to improve the long-term work intentions of nursing students in graduation year after identifying the level of long-term work intentions and checking factors affecting them.

• Journal of the Korea Convergence Society
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• v.13 no.3
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• pp.363-370
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• 2022

This study was execute to find out the influence of strengths knowledge and nursing professionalism on career identity in nursing students. Data were collected from nursing students attending in the nursing departments in G and M cities from July to September 2021. Among the collected data, 198 data were analyzed by descriptive statistics, t-test, ANOVA, Pearson's correlation coefficient, and controlled regression analysis. As a result of data analysis, strengths knowledge(β=.473, p<.001) and nursing professionalism(β=.167, p<.01) reported to have effect on career identity. The study model accounted for 48.2% of career identity. These findings suggest that program to improve strengths knowledge and nursing professionalism should be developed and operated to promote career identity of nursing students in the nursing education field.

• The Journal of Korean Academic Society of Nursing Education
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• v.28 no.2
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• pp.156-166
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• 2022

Purpose: The purpose of this study was to identify factors that can affect transition shock in newly-graduated nurses. Methods: The first descriptive written survey was conducted on 450 graduate students from five nursing colleges. After their employment, the second survey was conducted on 316 participants who had responded to the first survey. A total of 158 respondents were used for the final analysis. Data were analyzed using an independent t-test, ANOVA, Tukey test, Pearson's correlation coefficient, and hierarchical multiple regression analysis with the SPSS Win 25.0 Program. Results: The average age of the participants was 24.25±4.47. Of the participants, 126 (79.8%) were satisfied that they had majored in nursing. The average score for transition shock was 2.61±0.55 points. Factors influencing the transition shock of newly-graduated nurses were the working department, working period, and working environment. The more positively the newly-graduated nurses perceived the nursing work environment, the less of a transition shock they experienced. Grade point average, clinical competence, confidence in performing core nursing skills, and nursing professionalism did not affect their transition shock. It could be confirmed that there is a gap between college nursing education and the clinical field. Conclusion: In order to reduce the transition shock of newly-graduated nurses, it is necessary to improve the nursing work environment and apply educational and emotional support strategies according to the characteristics of each work department and the period of work.

• Advances in concrete construction
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• v.14 no.2
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• pp.103-113
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• 2022

On the basis of fabrication, the utilization of nano material in numerous industrial and technological system, obtained the utmost significance in current decade. Therefore, the current investigation presents a theoretical disposition regarding the flow of electric conducting Williamson nanoliquid over a stretchable surface in the presence of the motile microorganism. The impact of thermal radiation and magnetic parameter are incorporated in the energy equation. The concentration field is modified by adding the influence of chemical reaction. Moreover, the splendid features of nanofluid are displayed by utilizing the thermophoresis and Brownian motion aspects. Compatible similarity transformation is imposed on the equations governing the problem to derive the dimensionless ordinary differential equations. The Homotopy analysis method has been implemented to find the analytic solution of the obtained differential equations. The implications of specific parameters on profiles of velocity, temperature, concentration and motile microorganism density are investigated graphically. Moreover, coefficient of skin friction, Nusselt number, Sherwood number and density of motile number are clarified in tabular forms. It is revealed that thermal radiation, thermophoresis and Brownian motion parameters are very effective for improvement of heat transfer. The reported investigation can be used in improving the heat transfer appliances and systems of solar energy.

• Ocean and Polar Research
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• v.44 no.3
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• pp.235-247
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• 2022

A marine protected area (MPA) is a spatially designated section of the ocean where the biodiversity is high. Munseom MPA has a unique underwater landscape including soft coral, subtropical fish, and benthos, attracting many scuba divers. This paper intends to evaluate the willingness-to-pay (WTP) for the scuba diving management policy in the Munseom MPA. As a stated preference valuation method, a choice experiment was applied to assess divers' preferences with economic values for the policy. The attributes used in the study included zoning (temporal closure), conservation education, daily permit, soft coral area, and diving fee. We collected 333 questionnaires through online and field surveys and used 296 after excluding incomplete responses for the final data analysis. Study results show that a six-month closure, a decrease in soft coral habitat, and the diving fee were statistically significant. A positive coefficient with regard to the six-month closure variable indicates that divers preferred the policy, and the marginal willingness to pay (MWTP) was estimated to be KRW 8,637 per person per dive. The aggregate WTP of KRW 233 million was obtained by multiplying the MWTP by the number of visiting divers per year. When comparing the levels of recreation specialization, more skilled divers preferred the management option. The results of this study will help predict the priority of management measures and the levels of acceptability among divers when diving management is implemented in Korea in the future. This study suggests that marine environmental policies need to consider divers as one of the important stakeholders for marine conservation.