Earticle

In this paper, we proposed a multi-subject-level sentiment analysis model for user reviews using the Latent Dirichlet Allocation (LDA) method targeting user-generated content (UGC). Data were collected from users' online reviews of hotels in major tourist cities in the world, and 30 hotel-related topics were extracted using the entire user reviews through the LDA technique. Six major hotel-related themes (Cleanliness, Location, Rooms, Service, Sleep Quality, and Value) were selected from the extracted themes, and emotions were evaluated for sentences corresponding to six themes in each user review in the proposed sentiment analysis model. Sentiment was analyzed using a dictionary. In addition, the performance of the proposed sentiment analysis model was evaluated by comparing the emotional values for each subject in the user reviews and the detailed scores evaluated by the user directly for each hotel attribute. As a result of analyzing the values of accuracy and recall of the proposed sentiment analysis model, it was analyzed that the efficiency was high.

The causes of climate change are natural and artificial. Natural causes include changes in temperature and sunspot activities caused by changes in solar radiation due to large-scale volcanic activities, while artificial causes include increased greenhouse gas concentrations and land use changes. Studies have shown that excessive carbon use among artificial causes has accelerated global warming. Climate change is rapidly under way because of this. Due to climate change, the frequency and cycle of infectious disease viruses are greater and faster than before. Currently, the world is suffering greatly from coronavirus infection-19 (COVID-19). Korea is no exception. The first confirmed case occurred on January 20, 2020, and the number of infected people has steadily increased due to several waves since then, and many confirmed cases are occurring in 2021. In this study, we conduct a study on climate change before and after COVID-19 using weather data from Korea to determine whether climate change affects infectious disease viruses through logistic regression analysis. Based on this, we want to classify before and after COVID-19 through a logistic regression model to see how much classification rate we have. In addition, we compare monthly classification rates to see if there are seasonal classification differences.

Due to the recent increase in the mobile streaming market, mobile traffic is increasing exponentially. IMT-2020, named as the next generation mobile communication standard by ITU, is called the 5th generation mobile communication (5G), and is a technology that satisfies the data traffic capacity, low latency, high energy efficiency, and economic efficiency compared to the existing LTE (Long Term Evolution) system. 5G implements this technology by utilizing a high frequency band, but there is a problem of path loss due to the use of a high frequency band, which is greatly affected by system performance. In this paper, small cell technology was presented as a solution to the high frequency utilization of 5G mobile communication system, and furthermore, the system performance was improved by applying machine learning technology to macro communication and small cell communication method decision. It was found that the system performance was improved due to the technical application and the application of machine learning techniques.

The effect of improving awareness by educational programs for improving the quality of daily life of the disabled and safety depends on the type of disability and individual differences, as well as the difficulty in evaluating education achievement and satisfaction. However, more effective programs can be developed and provided if the factors affecting the effectiveness of education can be identified. Training as one of the factors affecting effectiveness involves motivation. This is thought to be an important factor for any object regardless of the type of disability. It is recognized that "By providing programs for the disabled to immerse themselves, they can be motivated to participate in education and expect greater effects on educational effects." Gamification is convincing enough for general learning. Furthermore, a feature of gamification is the use of the game's structure to achieve its goal, which acts on participants' motivation. Some use game packages such as analog games and digital games, but some include gamification of activities themselves. The use of gamification in education has different characteristics from the development of businesses. Therefore, in this paper, we reviewed the current status and challenges with the aim of promoting the use of gamification in life safety education for the disabled.

This paper discusses on the implementation of blockchain system, specifically the private system for Energy trading purpose. Blockchain is records bundled together in blocks and added to the chain after ledger is generated. All the blocks in the entire networks should be same contents and also only the permitted nodes can join the chain in the private blockchain system, thus not that same block and permitted nodes cannot be accepted in terms of proof-of-work phase. We implement the all stages which are necessary to process blockchain system. After coding the whole process, we test and conclude that the system is correctly working in terms of the functions implemented.