• Korean Journal of Soil Science and Fertilizer
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• v.48 no.6
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• pp.618-627
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• 2015

Soil salinity is the most critical factor for crop production at reclaimed tidal saline soil. Subsurface drainage system is recognized as a powerful tool for the process of desalinization in saline soil. The objective of this study was to investigate the effects of subsurface drainage systems on soil salinity and corn development at Saemangeum reclaimed tidal saline soil. The field experiments were carried out between 2012 and 2014 at Saemangeum reclaimed tidal land, Buan, Korea. Subsurface drainage was installed with four treatments: 1) drain spacing of 5 m, 2) drain spacing 10 m, 3) double layer with drain spacing 5 m and 10 m, and 4) the control without any treatment. The levels of water table showed shorter periods above 60 cm levels with the deeper installation of subsurface drainage system. Water soluble cations were significantly greater than exchangeable forms and soluble Na contents, especially in surface layer, were greatly reduced with the installation of subsurface drainage system. Subsurface drainage system improved biomass yield of corn and withering rate. Thus, the biomass yield of corn was improved and the shoot growth was more affected by salinity than was the root growth. The efficiency of double layer was not significant compared with the drain spacing of 5 m. The economic return to growers at reclaimed tidal saline soil was the greatest by the subsurface drainage system with 5 m drain spacing. Our results demonstrated that the installation of subsurface drainage system with drain space of 5 m spacing would be a best management practice to control soil salinity and corn development at Saemangeum reclaimed tidal saline soil.

• Journal of radiological science and technology
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• v.44 no.5
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• pp.545-554
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• 2021

According to the changes of the medical environment of the times, it is necessary to discuss the issues of the doctor's medical guidance and to conduct continuous research so that alternatives can be prepared systematically. Furthermore, in order to enhance the professionalism of radiological technologists and to develop the medical technician system, the new Radiological Technologist Independent Act has been established, which contains the overall contents of the scope of work, professional qualifications, and specialized education of radiological technologists, and provides quality medical services to patients through professional procedures and treatment. In order to increase the level of medical care, the purpose, definition, mission, role, and scope of work specified in the Medical Act, Medical Service Technologists, etc. Act, the Enforcement Decree, and the Enforcement Rules were variously analyzed and new directions were presented. First, the definition of a medical technician should use a generic term so that the factors of conflict and prejudice could be resolved. Second, change the doctor's guide to doctor's prescription; and then legislate the authority to sign and write medical records after examination by radiological technologists, thereby prohibiting unlicensed technicians that seriously endanger patient safety. Third, an accurate definition of radiological technologists' roles should be established; not only selection and management of radiological technologists' work but also procedures and treatment for each radiology field should be specified to suit the current medical system. Fourth, a professional radiological technologists' qualification system and a specialized education system should be established in order to secure human resources that could provide patients trust in procedures and treatment based on professional knowledge and experience in the field of radiology. Fifth, the Education and Evaluation Institute should be operated in Korea education system to educate the professional knowledge and competency for students. In addition, it is necessary to in-depth analysis of foreign cases could be applied to the medical system and education system in Korea; it could strive to nurture systematic human resources.

• Journal of Digital Convergence
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• v.19 no.12
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• pp.531-539
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• 2021

Given the rapid development of information and communication technology (ICT) and the deepening of the information gap phenomenon in the context of the COVID-19 pandemic, researchers and practitioners need to understand the changing perceptions of new phenomena such as COVID-19 information gap on the existing information-vulnerable population. In this study, an empirical analysis was performed with the digital information gap survey data in 2020 to understand the potential impact of COVID-19 on the information gap according to the information-vulnerable class. This study is to verify the effect of information gap, marginalized groups, gender, and major factors of information services (contents, social relations, life services, information production, networking, social participation, non-face-to-face services) on the change in perception of digital information technology after Corona. Hierarchical regression analysis was performed. As a result of the analysis, it was found that the higher the content, social relationship, life service, networking, and digital non-face-to-face service, the higher the change in perception of digital information technology after Corona. Therefore, in light of the evolving phenomenon of COVID-19, it is considered that the government needs to provide education and training to strengthen the capabilities of the information-vulnerable class in order to resolve the digital information gap.

• Journal of Convergence for Information Technology
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• v.11 no.11
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• pp.143-150
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• 2021

It introduces the contents of establishing a geostationary satellite-based forest fire monitoring system that can monitor areas of the Korean Peninsula 24 hours a day for forest fire monitoring, and describes how to establish a forest fire monitoring system and use it in various ways. In order to establish a satellite-utilized forest fire monitoring system, we will describe and draw conclusions on literature research, technical principles, forest fire monitoring means, and satellite forest fire monitoring system. The satellite-utilized forest fire monitoring system can consist of one geostationary satellite equipped with infrared detection optical sensors and a ground processing station that processes data received from satellites to spread surveillance information. Forest fire monitoring satellites are located in the country's geostationary orbit and should be operated 24 hours a day, 365 days a day. Forest fire monitoring technology is an infrared detection technology that can be used in national public interests such as forest fire monitoring and national security. It should be operated 24 hours a day, and to satisfy this, it is efficient to establish a geostationary satellite-based forest fire monitoring satellite system.

• Journal of Practical Engineering Education
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• v.13 no.2
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• pp.333-349
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• 2021

The fourth industrial revolution based on information and communication technology has increased the need for an environment where contents in new technologies can be learned for the development of lifelong vocational capabilities. To prepare for this, K University's online lifelong education center has established STEP, a smart learning platform. In this study, we conducted a study and other platform case analysis for STEP learner types, a survey of learners, and a comprehensive analysis based on these results to classify characteristics by learner types. It also intended to establish a plan to provide customized services to meet the needs of STEP learners in the future. The derived results are as follows. It is necessary to constantly manage learning content difficulty and learning motivation survey, and also needs to refine the operation of learning content in terms of learning composition. In addition, it is important to secure specialized content, to manage vulnerable learners, to actively introduce a learner support system and various educational methods.

• Clean Technology
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• v.27 no.3
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• pp.247-254
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• 2021

In this study, an eco-friendly combustion process of waste 2,4,6-trinitrotoluene (TNT: 2,4,6-trinitrotoluene) was developed, and fundamental data for the quantity of the organic matter in the final combustion residues is presented. Because complete combustion of TNT is not possible theoretically, the combustion process was optimized to reduce organic matter content in the combustion residue by performing measures such as heating time changes, addition of propellant material, and after treatment using a high-temp electrical furnace. From the results, it was confirmed that the organic matter content in the residue could be decreased to 7 ~ 10% with each method. The quantity of the organic matter could be minimized by optimizing the combustion conditions of the process. With only a combustion time increase, the amount of organic matter in the combustion residues was measured at about 9 wt%. The environmental friendliness of the final exhaust gas was also confirmed by real time gas component analyses. In addition, the organic contents could be reduced by a further 2 wt% by applying an additional heat treatment using an external electric furnace after the first incineration treatment. In the combustion process of propellant added waste TNT, it was found that various TNT wastes could be treated using the same eco-friendly protocols because the organic content in the residue decreased in accordance with the amount of propellant. The amount of the organic matter content produced by all these methods fulfilled the requirements under the Waste Management Act.

• Journal of Digital Convergence
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• v.19 no.7
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• pp.379-390
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• 2021

In this study, we produced kimchi with cooked Dioscorea batatas yam. Sliced kimchi cabbage, processed white radish kimchi (kkakdugi), and whole kimchi cabbage were prepared with 3% Dioscorea batatas, the nutritional and sensory properties were evaluated. The three types of D. opposita kimchi showed energy content in the range of 35-40 kcal per 100 g, and no crude fat, saturated fat, trans fat, or cholesterol was detected. Sodium content was 450-650 mg, with sliced cabbage kimchi showing the highest concentration. The vitamin C content increased significantly after 28 days of storage, with the sliced cabbage kimchi and whole-cabbage kimchi showing larger increases than the radish kimchi. All three types of D. opposita kimchi showed high Ca, K, and Mg contents. The whole-cabbage kimchi maintained salinity at a level of 2.38-2.72% from immediately after preparation to 28 days of storage compared to sliced cabbage kimchi and radish kimchi. Sliced cabbage and whole kimchi cabbage kimchi showed an increase in lightness and a decrease in redness with longer storage duration. Compared to the control groups, the experimental groups (with added D. opposita) showed higher yellowness. The hardness of the three types of kimchi decreased with longer storage duration. In sensory evaluation, there were no significant differences between the control groups and the experimental groups.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.2
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• pp.115-121
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• 2021

This paper used big data and artificial intelligence technology to predict the rapidly increasing internet traffic. There have been various studies on traffic prediction in the past, but they have not been able to reflect the increasing factors that induce huge Internet traffic such as smartphones and streaming in recent years. In addition, event-like factors such as the release of large-capacity popular games or the provision of new contents by OTT (Over the Top) operators are more difficult to predict in advance. Due to these characteristics, it was impossible for an ISP (Internet Service Provider) to reflect real-time service quality management or traffic forecasts in the network business environment with the existing method. Therefore, in this study, in order to solve this problem, an Internet traffic collection system was constructed that searches, discriminates and collects traffic data in real time, separate from the existing NMS. Through this, the flexibility and elasticity to automatically register the data of the collection target are secured, and real-time network quality monitoring is possible. In addition, a large amount of traffic data collected from the system was analyzed by machine learning (AI) to predict future traffic of OTT operators. Through this, more scientific and systematic prediction was possible, and in addition, it was possible to optimize the interworking between ISP operators and to secure the quality of large-scale OTT services.

• Korean Journal of Ichthyology
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• v.33 no.2
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• pp.84-94
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• 2021

This study was conducted to elucidate the impact of invasive species, Micropterus salmoides and Lepomis macrochirus in Geumgyeji, Samgaji and Naejangji reservoirs of National Parks, Korea in 2020. In the Geumgyeji, 1,221 individuals of 11 species in 7 families were collected including M. salmoides (relative abundance, 96.3%) and L. macrochirus (0.3%), M. salmoides fed mainly on Rhinogobius brunneus (IRI, 37.2%), Odonata (25.6%), Megaloptera (11.6%), and M. salmoides (7.0%). In the results of Samgaji showed that 854 individuals of 10 species in 5 families were collected including M. salmoides (60.8%), and M. salmoides fed mainly on Decapoda (shrimp, 33.6%), Odonata (34.4%), R. brunneus (21.2%), and Zacco platypus (6.1%). In the Naejangji showed that 1,075 individuals of 13 species belonging to 7 families were collected including L. macrochirus (38.1%) and M. salmoides (9.5%), and L. macrochirus fed mainly on Branchiopoda (77.5%), Diptera (9.8%), Decapoda (4.0%) and M. salmoides fed mainly on R. brunneus (73.3%), Decapoda (21.2%). M. salmoides of Geumgyeji and Samgaji were apparently introduced more than a 10 years ago. The fish population declined rapidly since the introduction of M. salmoides. L. macrochirus of Naejangji was introduced more than 20 years ago, which increased its relative abundance to 40%. M. salmoides was introduced five to six years ago, and the fish species and population declined rapidly since the introduction of M. salmoides. Finally, we discussed the inhabitat status and management of M. salmoides and L. macrochirus in the National Park.

• Journal of the Korea Convergence Society
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• v.12 no.7
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• pp.113-123
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• 2021

This study aims to present a plan to develop the funeral culture industry based on the results of a survey on the contents of funeral culture awareness, funeral culture industry development, and funeral culture education according to age groups. The survey in this study was researched by Gallup Korea, and the survey method was an online research using a structured questionnaire. The survey was conducted twice, from February 5, 2021 to February 8, 2021, and from February 18, 2021 to February 19, 2021. The effective subjects are 316, and the sampling method is allocated by sex and age. As a result of the study, cremation was preferred by all age groups, and the places where cremated remains were placed were high in the natural burials and ossuary hall. Although there are some differences by age groups, it was surveyed that generally, the elderly than the younger were less reluctant to sign up for condolence products, funerals in life, farewell trips, purchase farewell travel products, funeral insurance, and counsel with death-related experts. The results of this study are expected to contribute to interdisciplinary convergence research on the recognition and development of the funeral culture industry.