• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.2
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• pp.15-23
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• 2021

This study was conducted to evaluate the field application of the developed recommendation system in organic rice (Oriza sativa L.) paddy and to investigate the mineral nitrogen content in soil and rice productivity. According to the developed system, hairy vetch (HV), rye+rapeseed oil cake (R+OC), rapeseed oil cake (OC) for only basal fertilization (OC-B), OC for split application (OC-S), pig manure compost (PMC), and chemical fertilizer (CHM) were applied to paddy soil at the rate of 107~133 kg N/ha. Results were followed, unhulled rice yield of OC-S (111%), OC-B (110), R+OC (106), HV (101), and PMC (96) were no significantly different with CHM (100). Also there was positive correlation (R²=0.803^*) between unhulled rice yield and cumulative inorganic N in soil. For nitrogen use efficiency of rice, OC-B, OC-S, and R+OC were not significantly different with CHM. In conclusions, the developed organic materials use recommendation system was effective for organic rice productivity. It could be useful for organic farmer to apply the organic materials use recommendation system for rice.

• Journal of Digital Convergence
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• v.19 no.2
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• pp.61-69
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• 2021

The military pension deficit is increasing due to an increase in the average life expectancy and pension option rate, and a significant reason for this is estimated to be a continued increase in the number of military pension recipients. In terms of the soundness of military pension finances, this paper uses the Markov chain model to validate the stability of the military group, suggesting the direction of future military pension system in terms of the ratio of pension receipts to employees, and verifying the feasibility of the method applied through verification. Through this paper, we have confirmed that the initial 45,270 military personnel converge to 43,141 after a certain period of time and reach a stable state, which is expected to help us to estimate the long term size of military pension recipients to confirm the direction of national financial support. Military man who are eligible for pensions for more than 20 years have a relatively low rate of turnover or retirement compared to ordinary private groups, making it easier to define their status and simplify state transition probabilities. Therefore, it is expected that the sustainability of the military pension will be confirmed from a long term perspective by viewing the military group as a system and applying it to the Markov chain model by checking the probability of transfer of status such as promotion, maintaining the current grade, and retirement during the period.

• Journal of Christian Education in Korea
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• v.64
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• pp.109-144
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• 2020

In the 21st century, Our Korean churches should be reborn and truly restored in the situation korean churches have been criticized socially and adversely affected Christian missions. In this situation, the researcher analyzed the Zeraim(Agriculture) of the Jewish scripture Talmud as an alternative to solving the problems of the Korean church. In order to achieve the purpose of this research, the background of the emergence of Talmud, the main contents of Talmud Zeraim, and the application of Talmud Zeraim's Christian education were divided and analyzed. Through the Jewish Talmud Zeraim, five possibilities of application were suggested to solve the problems of Korean churches. First, it is a Christian education for a blessed life. Second, it is a Christian education that pursues social justice, life, and integrity of creation. Third, it is Christian education for a life that appreciates God's grace. Fourth, it is a Christian education for realizing the commandments and practicing the teachings. Fifth, it is a Christian education that pursues conventional spirituality. Researchers believe that the mission and direction of Christian education without losing their identity and faith under the numerous hardships in history should be found in the faith and life of Jews who have regained their traditional spirituality centered on the law (Torah) and Talmud which are the God's words. From now on, the Korean church should boldly clear up its mistakes and move on to education that humbly accepts the sounds of social criticism and can make a fresh recovery.

• The Korean Journal of Applied Statistics
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• v.33 no.6
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• pp.777-789
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• 2020

COVID-19 has been rapidly spread world wide since late December 2019. In this paper, our interest is to estimate distribution of incubation time defined as period between infection of virus and the onset. Due to the limit of accessibility and asymptomatic feature of COVID-19 virus, the exact infection and onset time are not always observable. For estimation of incubation time, interval censoring technique is implemented. Furthermore, a competing risk model is applied to estimate the case fatality and cure fraction. Based on the result, the mean incubation time is about 5.4 days and the fatality rate is higher for older and male patient and the cure rate is higher at younger,female and asymptomatic patient.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.1
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• pp.184-192
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• 2022

Valve internal leakage is caused by damage to the internal parts of the valve, resulting in accidents and shutdowns of the piping system. This study investigated the possibility of a real-time leak detection method using the acoustic emission (AE) signal generated from the piping system during the internal leakage of a butterfly valve. Datasets of raw time-domain AE signals were collected and postprocessed for each operation mode of the valve in a systematic manner to develop a data-driven model for the detection and classification of internal leakage, by applying machine learning algorithms. The aim of this study was to determine whether it is possible to treat leak detection as a classification problem by applying two classification algorithms: support vector machine (SVM) and convolutional neural network (CNN). The results showed different performances for the algorithms and datasets used. The SVM-based binary classification models, based on feature extraction of data, achieved an overall accuracy of 83% to 90%, while in the case of a multiple classification model, the accuracy was reduced to 66%. By contrast, the CNN-based classification model achieved an accuracy of 99.85%, which is superior to those of any other models based on the SVM algorithm. The results revealed that the SVM classification model requires effective feature extraction of the AE signals to improve the accuracy of multi-class classification. Moreover, the CNN-based classification can be a promising approach to detect both leakage and valve opening as long as the performance of the processor does not degrade.

• Journal of Navigation and Port Research
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• v.46 no.3
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• pp.269-279
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• 2022

With the development of artificial intelligence, artificial intelligence is being introduced to automate systems throughout the industry. In the maritime industry, artificial intelligence is being applied step by step, through the paradigm of autonomous ships. In line with this trend, ABS and DNV have published guidelines for autonomous vessels. However, there is a possibility that the risk of artificial intelligence has not been sufficiently considered, as the classification guidelines describe the requirements from the perspective of ship operation and marine service. Thus in this study, using the standards established by the ISO/ IEC JTC1/SC42 artificial intelligence division, classification requirements are classified as the causes of risk, and a measure that can evaluate risks through the combination of risk causes and artificial intelligence metrics want to use. Through the combination of the risk causes of artificial intelligence proposed in this study and the characteristics to evaluate them, it is thought that it will be beneficial in defining and identifying the risks arising from the introduction of artificial intelligence into the marine system. It is expected that it will enable the creation of more detailed and specific safety requirements for autonomous ships.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.2
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• pp.115-123
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• 2022

This study was performed to determine carbon (C) storage of urban parks [Hadae park (established year: 1977), Songlim park (established year: 1990), Pyeonggeo park (1992), Chojeon park (2005)] in Jinju-si, Gyeongsangnam-do. The soil at 0-30 cm depth was collected to measure soil C concentration. Bulk density in all soil depths was not significantly different among the four parks, whereas coarse fragments (>2 mm) were significantly higher in the Chojeon park than in the Pyeonggeo park. Soil pH and electrical conductivity were highest in Chojeon park among four parks. Soil C concentrations in all soil depths were significantly higher in the Hadae park established in 19 77 compared with the other parks established since 1990. Mean soil C concentration at 0-30 cm was the highest in the Hadae park (1.04%), followed by the Chojeon park (0.87%), the Songlim park (0.75%), and the Pyeonggeo park (0.57%). Soil C storage at 0-10 cm was not significantly different among the four urban parks, whereas soil C storage at 10-20 cm and 20-30 cm was higher in the Hadae parks than in the other parks. Total soil C storage was significantly higher in the Hadae park (28,425 kg C ha^-1) than in the Pyeonggeo park (15,622 kg C ha^-1). Mean soil C concentration and C storage were positively correlated with silt content and negatively correlated with sand content. The results suggest that soil C storage of urban parks in Jinju-si might be related to the established period of parks and silt contents.

• The Journal of the Korea Contents Association
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• v.22 no.3
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• pp.309-321
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• 2022

As the spread of COVID19 has compelled activities in various fields to transform to adapt to the non-face-to-face environment, various activities have either already been transitioned into non-face-to-face methods or been searching for alternative methods to carry out activities in a non-face-to-face manner. However, there are apparent limits in handling this transition with the pre-existing digital technology. Ironically, said limitations are more apparent in the UX design field that has thus far emphasized resolutions based on digital technology. The reason for this stems from the nature of UX design which strongly emphasizes the importance of collaboration. Especially, in the field of UX design, problems are expected to surface under areas of communication and collaboration in workshops, which are productive means of collecting the ideas of interested parties and coming up with other new ideas. Based on the aforementioned rise of necessity, this study aims to assess the characteristics of workshops in the field of UX design and suggest an effective method of transitioning UX workshops into a non-face-to-face environment. Along the line of this process, this study has created a standard process in regards to design workshops with active creation, suggestion, and acceptance of ideas, among the various types of workshops defined by the Nielsen Norman Group. This study also developed a framework consisting of non-face-to-face workshops by combining with the standard process the methodologies of workshop activation and non-face-to-face services meant for communication and designing activities, and confirmed the adaptability and the effectiveness of said transition against various types of workshops. Application of the results of this study is expected to effectively lead the transition into the non-face-to-face environment and improve the collaborative efforts of the interested parties via workshops.

• Korean Association of Arts Management
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• no.59
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• pp.73-99
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• 2021

Free admission policies have been gradually extended for the public to use cultural facilities free of charge, which lowered the barriers to use those facilities and has a great effect on increasing visitor demands. However, the annual number of visitors which is open to the public isn't quite accurate and varies from institution to institution, which means just a head count. Especially people counter overestimates the number of visitors because it counts visitors in duplicate. Therefore, the purpose of this study is to prepare effective way of grasping the number of visitors using cultural infrastructure. First, comparable number of visitors should be measured by defining the notion of visitor clearly, which has been measured vaguely. Secondly, the problem of duplicate count, which is considered the most problematic, should be solved. Thirdly, the various analysis of visitor behavior should be conducted to provide a high-quality service. To work out the problems above, new measurement will be presented here. This study suggests a state-of-the-art wireless signal-based measurement that could eliminate the duplicate data by collecting MAC address -smart device's distinct signal value. And it also could analyze diverse visitor behaviors by understanding a flow of visitor traffic, duration of stay and revisitation. I would like to examine the possibility and effectiveness of this new measurement by testing it.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.32 no.6
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• pp.219-224
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• 2022

CaF₂ single crystal has a large band gap (12 eV), and it is used for optical windows, prisms, and lenses due to its excellent transmittance in a wide wavelength range and low refractive index. Moreover, it is expected to be one of the materials for ultraviolet transmissive laser optical components. CaF₂ belongs to the fluoride compounds and has a face-centered cubic (FCC) structure with three sub-lattices. The representative method for CaF₂ single crystal growth is Czochralski, which method has the advantages of high production efficiency and the ability to make large crystals. In this study, X-ray diffraction (XRD), X-ray rocking curves (XRC) measurement, and chemical etching were performed to analyze the crystallinity and defect density of the CaF₂ single crystals, grown by the Czochralski method. Fourier-transform infrared spectroscopy (FT-IR) and UV-VIS-NIR spectroscopy systems were used to investigate the optical properties of the CaF₂ crystal. The provability of various applications, including UV application, was systematically investigated with various analysis results.