• Korean Journal of Heritage: History & Science
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• v.48 no.4
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• pp.74-93
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• 2015

Geophysical survey of Korea was introduced in Nara National Research Institute of Cultural Heritage in 1995. At that time, it has been activated geophysical survey of architecture and civil engineering in Korea. But there was no exploration experts to be combined the archaeology. For this reason, National Research Institute of Cultural Heritage has introduced the physical exploration. Through the expert exchanges South Korea and Japan carried out joint exploration. And it has increased the reliability of the exploration method and exploration results. It is GPR the most method commonly in geophysical exploration. There are many usability before excavation because of good resolution. However, the shallow GPR penetration depth has limitations in large mounds. We were able to take advantage of the resistivity analysis program to study the underground structure to deep through the experts exchange. We was able to get a good result that overcomes the limitations of GPR exploration in a number of burial mounds including Naju bokamri by the resistivity analysis program. In particular, we confirmed the location of the burial main body by compares the results of exploration and excavation results. In the future we will perform a convergence research of exploration and archaeology through a variety of joint research. In addition we will have to build a new network of archaeological science.

• Journal of Korean Library and Information Science Society
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• v.50 no.2
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• pp.149-168
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• 2019

The purpose of this study is to analyze the characteristics of teacher librarians' efficacy and to propose some ways to enhance their efficacy. To do this, questionnaires on 30 teacher librarians who participated in the level 1 certification program of K university in 2018 were conducted. The results showed that their average efficacy was 3.38, the efficacy of teaching method was 3.60, the collective efficacy was 3.38, and the personal efficacy was 3.18. They had high personal efficacy on classroom management, the willingness to lead poor students and the possibility of problem student guidance, and collective efficacy on conflict management with fellow teachers and parents. On the other hand, personal efficacy in problem analysis and guidance for problem students, difficult contents and course instruction were low. Also, the collective efficacy of the conflict between the manager and the education office was low. They have a strong willingness to improve teaching methods for students and showed high efficacy about student synchronization and preparation for teaching. However, they were aware of the lack of learning skills and the lack of various teaching methods. The variables influencing their efficacy were graduation, education level, school size, and degree. Especially, the higher the education level, the more confident and enthusiastic about teaching problemmatic students and disadvantaged students. In addition, teacher librarians with high academic standards showed high confidence in conflict resolution with peers and parents and teaching methods. The improvement direction to enhance their efficacy in this study are increasing the ratio of teacher education in the field of education, reforming teacher librarians training before appointment, establishing supervision organizations for school libraries and improving their professionalism by going to graduate school.

• Korean Journal of Ecology and Environment
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• v.52 no.2
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• pp.143-150
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• 2019

Although inconspicuous marsh birds are an indicator of marsh health, there is little understanding of their status and population trends due to their behavioral characteristics and lack of reliable survey methods in Korea. We applied the Standardized North American Marsh Bird Monitoring Protocols(SNAMBMP) already validated in North America for effective survey of the marsh birds. We selected 29 sites with emergent marshes, rice fields and riparian forests in Seocheon-gun, Buyeo-gun and Gunsan-si. We conducted the survey with a combination of passive 5 minute point-count and vocal survey method (30 seconds call-broadcasting+30 seconds silence) that was targeted eight species 2~7 times/site from March to July 2017. Four species, Brown-cheeked Rail(Rallus indicus), Ruddy-breasted Crake (Porzana fusca), Watercock (Gallicrex cinerea) and Greater Painted-snipe (Rostatula benghalensis), were detected at one site respectively (naïve occupancy rate=0.035). Vocal survey method with conspecific call-broadcasting provided better on Brown-cheeked Rail and Watercock than the others. We suggest a combination of passive point-count and vocal survey method like SNAMBMP to monitor inconspicuous marsh birds at nationwide scale and collection of sound files through recording of the entire process during the survey.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.1
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• pp.177-188
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• 2019

The purpose of the optimization of the installation of supply/exhaust ports for tunnels with transverse ventilation system is to supply fresh air from outside to inside of tunnels uniformly and exhaust pollutant from tunnels properly for creating safe and clean environment for tunnel users. For this purpose, a ventilation port area optimization program was developed to obtain a uniform supply or exhaust air volume inside a great depth double deck tunnel with transverse ventilation system. In order to area optimize the developed port sizing program, the wind velocity was measured in the duct of the currently operated tunnel with semi-transverse ventilation. Also 3D cfd was performed on the same tunnel and cfd results were compared to the measured value. As a result, the error rate between the predicted value from the program and measured value was 6.72%, while the error rate between the predicted value from the program and 3D cfd analysis value was 4.86%. Both of comparison results show less than 10% of error rate. Thus It is expected that supply/exhaust port optimization design of transverse ventilation tunnel can be possible with using this large exhaust port area optimization program.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.2
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• pp.238-246
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• 2021

Collision of small vessels such as fishing boats cause great personal injury. Prior to this study, the collision prevention algorithm was developed to assess the collision risk and make the collision alarm. However, a service provided for safety, such as a collision warning, not only prevents risks, but also requires a certain degree of user satisfaction to function effectively. In this study, the collision prevention algorithm for small vessels was improved to be more practical, and the effects of the improvement were confirmed by applying the algorithm. A survey conducted on the users of the collision warning service confirmed the user requirements for improving the accuracy of the collision warning system and reducing the volume and number of alarms. Accordingly, the algorithm was improved for user satisfaction, and the actual vessel experiment was performed applying the improved algorithm in an actual maritime environment. As a result, the frequency of alarm occurrence decreased compared to former algorithm, but the alarm was relatively steadily generated in dangerous situations. It was analyzed that the accuracy and practicality of the collision alarm were improved. If the practicality and reliability of the improved algorithm are verified in the further study, it will be able to effectively contribute to the prevention of collisions of small vessels.

• Journal of the Society of Disaster Information
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• v.17 no.1
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• pp.120-127
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• 2021

Purpose: In this study, the effect of changes in the variables related to water droplets on the spray density on the floor in the analysis of the water mist fire protection system using FDS was analyzed. Method: When the spray of the water mist nozzle was analyzed in FDS, Particles Per Seconds, Particle Velocity, Size Distribution, and Spray Pattern Shape that can be set in relation to droplets were input to review the analyzed results. Result: In the analysis results, when the number of particles per second was set above a certain value, the spray density of the floor was similar. In the case of Particle Velocity, as the velocity decreases, the spray density of the central portion increases but decreases at a distance of 0.15m or more. From the analysis of the change in the size distribution function, it was found that an increase in the 𝛾 value increases the spray density of the central part, but the value at a remote location decreases. Compared to the result of applying the Gaussian distribution, the median value decreases dramatically when the uniform distribution is applied, but the value at the adjacent position increases. Conclusion: Variables related to the droplet properties of the FDS affect the spray density of the floor. Therefore, in order to increase the reliability of results before performing analyses such as fire suppression or cooling, a sufficient review of input variables is required.

• Journal of Intelligence and Information Systems
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• v.27 no.3
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• pp.1-27
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• 2021

The entire tourism industry is being hit hard by the COVID-19 as a global pandemic. Accommodation sharing services such as Airbnb, which have recently expanded due to the spread of the sharing economy, are particularly affected by the pandemic because transactions are made based on trust and communication between consumer and supplier. As the pandemic situation changes individuals' perceptions and behavior of travel, strategies for the recovery of the tourism industry have been discussed. However, since most studies present macro strategies in terms of traditional lodging providers and the government, there is a significant lack of discussion on differentiated pandemic response strategies considering the peculiarity of the sharing economy centered on peer-to-peer transactions. This study discusses the marketing strategy for individual hosts of Airbnb during COVID-19. We empirically analyze the effect of changes in listing descriptions posted by the Airbnb hosts on listing performance after COVID-19 was outbroken. We extract nine aspects described in the listing descriptions using the Attention-Based Aspect Extraction model, which is a deep learning-based aspect extraction method. We model the effect of aspect changes on listing performance after the COVID-19 by observing the frequency of each aspect appeared in the text. In addition, we compare those effects across the types of Airbnb listing. Through this, this study presents an idea for a pandemic crisis response strategy that individual service providers of accommodation sharing services can take depending on the listing type.

• Journal of Internet Computing and Services
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• v.21 no.6
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• pp.1-12
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• 2020

Low-Orbit satellite mobile networks can provide services through miniaturized terminals with low transmission power, which can be used as reliable means of communication in the national public disaster network and defense sector. However, the high traffic environment in the emergency preparedness situation increases the new call blocking probability and the handover failure probability of the satellite network, and the increase of the handover failure probability affects the QoS because low orbit satellites move in orbit at a very high speed. Among the channel allocation methods of satellite communication, the FCA shows relatively better performance in a high traffic environment than DCA and is suitable for emergency preparedness situations, but in order to optimize QoS when traffic increases, the new call blocking and the handover failure must be minimized. In this paper, we propose LEO-DBC (LEO satellite dynamic beam width control) technique, which improves QoS by adaptive adjustment of beam width of low-orbit satellites and call time of terminals by improving FCA-QH method. Through the LEO-DBC technique, it is expected that the QoS of the mobile satellite communication network can be optimally maintained in high traffic environments in emergency preparedness situations.

• The Journal of Bigdata
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• v.5 no.2
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• pp.241-255
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• 2020

In Korea, utilizing and protecting the ocean from the sea on three sides can be considered the basis of national power. Recently, it has been distributed to IOT and 5G networks, and attempts to provide various information based on telecommunication infrastructure are continuing in the public and private sectors. In this study, an online survey was conducted with the aim of improving the services of marine information services (KOMC, safe and open seas) provided by the Government Agency for Oceanographic Research. Through an online survey, the survey was conducted on sites that are mainly used to survey people's need for marine information and to collect information. In addition, the survey was conducted on the UX, UI problems and improvements of KOMC, open and safe sea sites provided by the National Oceanographic Research Institute. The awareness and experience of marine information service by the Korea Oceanographic Research Institute were confirmed. Later, the previous steps of FGI also examined the usability of various users after allowing them to use the actual service. Here, the experience of collecting marine information from actual users was investigated, not just by looking at and evaluating the design of the service website and application. As a result, users presented a variety of opinions related to marine information services, including accessibility, reliability of information, providing media, and importance of information provided. The findings could be used as data to identify ocean-related data and ways to provide information required by users of various age groups and occupational groups.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.26 no.1
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• pp.49-61
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• 2021

The repeated shipboard measurements that have been conducted by the National Institute of Fisheries Science (NIFS) for more than a half century, provide the valuable long-term hydrographic data with high spatial-temporal resolution. However, this unprecedent dataset has been rarely used for oceanic climate sciences because of its reliability issue. In this study, temporal variability of salinity error in the NIFS data was quantified by means of extremely small variability of salinity in the deep layer of the south-western East Sea, in order to contribute to studies on long-term variability of the East Sea. The NIFS salinity errors estimated on the isothermal surfaces of 1℃ have a remarkable temporal variation, such as ~0.160 g/kg in the year of 1961~1980, ~0.060 g/kg in 1981~1994,~0.020 g/kg in 1995~2002, and ~0.010 g/kg in 2003~2014 on average, which basically represent bias error. In the recent years, even though the quality of salinity has been improved, there still remain relatively large bias errors in salinity data presumably due to failure of salinity sensor managements, especially in 2011, 2013, and 2014. On the contrary, the salinity in the year of 2012 was very accurate and stable, whose error was estimated as about 0.001 g/kg comparable to the salinity sensor accuracy. Thus, as long as developing proper data quality control procedures and sensor management systems, I expect that the NIFS shipboard hydrographic data could have good enough quality to support various studies on ocean response to climate variabilities. Additionally, a few points to improve the current NIFS shipboard measurements were suggested in the discussion section.