• Journal of Wetlands Research
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• v.23 no.1
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• pp.27-34
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• 2021

In this study, the main influencing factors of the occurrence of cyanobacteria at each of the eight Multifunctional weirs were derived using a random forest, and a categorical prediction model based on a Algal bloom warning system was developed. As a result of examining the importance of variables in the random forest, it was found that the upstream points were directly affected by weir operation during the occurrence of cyanobacteria. This means that cyanobacteria can be managed through efficient security management. DO and E.C were indicated as major influencers in midstream. The midstream section is a section where large-scale industrial complexes such as Gumi and Gimcheon are concentrated as well as the emissions of basic environmental facilities have a great influence. During the period of heatwave and drought, E.C increases along with the discharge of environmental facilities discharged from the basin, which promotes the outbreak of cyanobacteria. Those monitoring sites located in the middle and lower streams are areas that are most affected by heat waves and droughts, and therefore require preemptive management in preparation for the outbreak of cyanobacteria caused by drought in summer. Through this study, the characteristics of cyanobacteria at each point were analyzed. It can provide basic data for policy decision-making for customized cyanobacteria management.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.2
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• pp.73-82
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• 2022

The study presents a three-dimensional approach to simulate the nonlinear behavior of a 72 m long Ultra High Performance Fiber Reinforced Concrete (UHPFRC) pre-stressed box girder for a pedestrian bridge in Busan, South Korea. The concrete damage plasticity (CDP) model is adopted to model the non-linear behavior of the UHPFRC material, in which the material properties are obtained from uniaxial compressive and tensile tests. The simulation model based on the proposed stress-strain curve is validated by the results of four-point bending model tests of a 50 m UHPFRC pre-stressed box girder. The results from the simulation models agree with the experimental observations and predict the flexural behavior of the 50 m UHPFRC pre-stressed box girder accurately. Afterward, the validated model is utilized to investigate the flexural behavior of the 72 m UHPFRC pre-stressed box girder. Here, the load-deflection curve, stress status of the girder at various load levels, and connection details is analyzed. The load-deflection curve is also compared with design load to demonstrate the great benefit of the slender UHPFRC box girder. The obtained results demonstrate the applicability of the nonlinear finite element method as an appropriate option to analyze the flexural behavior of pre-stressed long-span girders.

• Journal of the Korean Chemical Society
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• v.66 no.3
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• pp.209-217
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• 2022

We have developed photosensitive electrochromic smart windows that does not require any transparent conducting oxide (TCO) substrate. In our previous study, we demonstrated that a flexible film-type device made with a low temperature curing WO₃ sol and TiO₂ sol could show a reversible and rapid switching between colored and bleached state via incorporation of platinum catalysts on the surface of WO₃ layer. However, when these devices were exposed to sunlight over 4 hour, it was confirmed that they did not return to fully bleached state in the darkened state due to their overcoloring process. In this study, we added 4-hydroxy-(2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPOL) as an additive to the electrolyte of photosensitive electrochromic device to effectively prevent the undesired overcoloring process. The resulting device with TEMPOL indeed did not undergo excessive coloration and showed great reversibility even after being exposed to sunlight for over 4 hours. Various concentrations of TEMPOL were applied to compare changes in the visible transmittance and coloring/bleaching kinetics of devices. In terms of energetic point of view, we proposed a plausible mechanism of TEMPOL to prevent excessive coloration.

• Journal of Internet Computing and Services
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• v.23 no.1
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• pp.49-68
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• 2022

The operation system of a shipping company is still maintaining the mainframe based terminal access environment or the client/server based environment. Nowadays shipping companies that try to migrate it into a web-based environment are increasing. However, in the transition, if the design is processed by the old configuration and knowledge without considering the characteristics of the web-based environment and shipping business, various security vulnerabilities will be revealed at the actual system operation stage, and system maintenance costs to fix them will increase significantly. Therefore, in the transition to a web-based environment, a security design must be carried out from the design stage to ensure system safety and to reduce security-related maintenance costs in the future. This paper examines the characteristics of various threat modeling techniques, selects suitable modeling technique for the operation system of a shipping company, applies data flow diagram and STRIDE threat modeling technique to shipping business, derives possible security threats from each component of the data flow diagram in the attacker's point of view, validates the derived threats by mapping them with attack library items, represents the attack tree having various attack scenarios that attackers can attempt to achieve their final goals, organizes into the checklist that has security check items, associated threats and security requirements, and finally presents 23 security requirements that can respond to threats. Unlike the existing general security requirements, the security requirements presented in this paper reflect the characteristics of shipping business because they are derived by analyzing the actual business of a shipping company and applying threat modeling technique. Therefore, I think that the presented security requirements will be of great help in the security design of shipping companies that are trying to proceed with the transition to a web-based environment in the future.

• Informatization Policy
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• v.29 no.1
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• pp.38-59
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• 2022

The development of IT technology and the spread of smartphones are having a great impact on businesses and consumers. Consumers have been able to acquire more diverse and larger amounts of information than in the past due to information provided through smartphones and information search on the internet, which has a significant influence on decision-making. Companies have also become sensitive to such changes in consumer behavior patterns, reflected in their marketing. In addition, among the various characteristics of smartphones, location-based technology has become an important factor in providing targeted marketing from a company's point of view. Such technological development and social change have led to the expansion of the mobile advertising market, which promotes products or services based on the location of consumers and provides benefits such as discount coupons. In this study, we have analyzed the influence of consumer characteristics on intention to use in mobile location-based advertising, which has become an important marketing method in the mobile advertising market. The effects of variables of personalization, engagement, coupon proneness, economic efficiency, and irritation on attitude and information privacy concerns were analyzed, and the effects of attitude and information privacy concerns on intention to use were analyzed. The results of this study are deemed to be able to suggest factors to consider when providing mobile location-based advertising to consumers in the future.

• Journal of the Korean Society of Radiology
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• v.16 no.5
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• pp.603-609
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• 2022

The dose distribution in the human body was evaluated and analyzed through dosimetry data using water phantom, ionization chamber and simulated by Monte Carlo simulation for ^99mTc and ¹⁸F sources, which are frequently used in the nuclear medicine in this study. As a result of this study, it was found that the dose decreased exponentially as the distance from the radioisotope increased, and it particularly showed a tendency to decrease sharply when the radioisotope was separated by 5 cm. It means that a large amount of dose is delivered to an organ located within 4 cm of source's movement path when a source uptake in the human body. Numerically, it was formed in the rage of 0.16 to 2.16 pC/min for ^99mTc and 0.49 to 9.29 pC/min for ¹⁸F. In addition, the energy transfer coefficient calculated using the result was found to be similar to the measured value and the simulation value in the range of 0.240 to 0.260. Especially, when the measured data and the simulation value were compared, there was a difference is within 2%, so the reliability of the data was secured. In this study, the distribution of radiation generated from a source was calculated to quantitatively evaluate the internal dose by radioisotopes. It presented reliable results through comparative analysis of the measurement value and simulation value. Above all, it has a great significance to the point that it was presented by directly measuring the distribution of radiation in the human body.

• Korean Association of Arts Management
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• no.53
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• pp.207-247
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• 2020

is a project for the senior generation with humanistic knowledge to become a mentor and communicate with them to present the wisdom and direction of life to the new generations of mentees based on various life experiences. has been expanding since 2015, starting with the pilot operation in 2014. In general, projects such as these are assessed to establish effectiveness indicators to verify effectiveness and to establish project management and development strategies. However, most of the evaluations have been conducted quantitatively and qualitatively based on the short-term duration of the project. Therefore, in the case of continuous projects such as , especially in the field of culture and arts where long-term effectiveness verification is required, the short-term evaluation is difficult to predict and judge the actual meaningful effects. In this regard, tried to examine the qualitative change of key participants in this project through the 2017 and 2018 image tracking survey. For this purpose, we adopted qualitative research methodology through interview video shooting, field shooting, and value coding as a research method suitable for the research subject. To analyze the results, first, the interview images were transcribed, keywords were extracted, value encoding works were matched with human psychological values, and the theoretical method was used to identify changes and to derive the meaning. In fact, despite the fact that the study conducted in this study was a follow-up survey, it remained a limitation that it analyzed the changed pattern in a rather short time of 2 years. However, this study systemized the specific methodology that researchers should conduct for follow-up and provided the flow of research at the present time when there is hardly a model for follow-up in the field of culture and arts education business in Korea as well as abroad. Significance can be derived from this point. In addition, it can be said that it has great significance in preparing the detailed system and case of comparative analysis methodology through value coding.

• Journal of Korea Entertainment Industry Association
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• v.14 no.4
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• pp.199-209
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• 2020

"Positive Influence(PI)" of popular star has recently emerged as a social concern, but the lack of prior research has led to confusion over its concept and range of activity. On this point, this study carried out to lay the groundwork for discussions on the systematization of related theories, focused on identifying the current situations by analyzing articles for 15 months from January 2019 to March 2020 when related reports were in full swing. As a result of the analysis of the remarks from the entertainers mentioned in the articles, they were not clearly aware of the concept while doing good deeds under the name of PI in light of the study outcome by Aegean and Singer(2013). The motivations for good deed were classified into six types, including difficulty empathy, fandom reward, participation urge, nidana emphasis, experience subjugation, and memory evocation in the order of frequency of cases. Specific behaviors of PI were followed by donations of money and valuables for 54.4 percent, participation of social agendas for 14.0 percent, volunteering for 13.2 percent, joining campaign for 11.4 percent, other good deeds for 4.0 percent, and philanthropy for 3.0 percent. In occupational analysis, the concentration of donations was also evident. Their activities in the fields of human rights sensitivity, environmental protection and self-management, which are expected to have great effects with their influence, have been extremely poor. The results of the study first require academia to establish a interdisciplinary concept for PI. It also suggests that entertainers and their agencies should take far more strategic approach to evolve the PI event in a way that utilizes the advantages of each job group, such as actors, singers and comedians, and expands the diversity of areas.

• Science of Emotion and Sensibility
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• v.25 no.1
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• pp.129-142
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• 2022

This study evaluates a program developed for a high school-university linked class. The program combines maker education and smart clothing technology, which has great potential. First, in the preparation stage, the dyeing design course incorporates the contents of previous studies on smart clothing and maker education. Second, in the development stage, a program was developed to make emotional eco-bags by applying the transfer dyeing technique using transfer paper for inkjet printers and smart clothing technology using conductivity thread and LED bulbs. Third, in the implementation stage, the class was offered to 17 high school students who want to major in clothing and textiles. Lastly, the class was evaluated. The program had a 4.95 satisfaction level as measures on a five-point scale. Furthermore, this paper suggested an advanced program with Lilypad Arduino. In conclusion, through this study, it was confirmed that the emotional eco-bag development program applied with conductive yarn and transfer dye could more easily produce smart clothing technology, thereby expanding the thinking of high school students regarding the clothing major.

• Journal of Practical Engineering Education
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• v.14 no.2
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• pp.367-376
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• 2022

In this study, the user experience was analyzed from the learner's point of view, focusing on the metaverse platform 'Spatial'. SUS(System Usability Scale) was used to evaluate the usability of the metaverse platform 'Spatial' in a college class, and the Magnitude estimation technique was used to evaluate the immersion and satisfaction with the class. In addition, a questionnaire survey was used to collect user experience opinions on the use of 'Spatial' as a teaching tool. Looking at the usability evaluation results of the 'Spatial' system, the students evaluated the usability, immersion, and satisfaction quite positively. Looking at the user experience of metaverse platform 'Spatial', it was found that students highly valued Metaverse as an educational tool that can provide a place for many people to gather and communicate even in a non-face-to-face space. Compared to other online platforms, metaverse has advantages in ease of use, interaction, immersion, and interest. In particular, in addition to keyboard, touch, and display, interaction using the five senses such as voice, motion, and gaze was recognized as a great advantage. On the other hand, it was found that high openness, freedom, and interest factors can both promote learning and inhibit learning. Nevertheless, it is judged that the metaverse platform 'Spatial' can be effectively applied in college classes because it enables various interactions between instructor and learner or between learner and learner.