KJC Korea
Journal Central

Recently, an SSD with hybrid buffer memories is actively researching to reduce the overall latency in server computing systems. However, existing hybrid buffer policies caused many swapping operations in pages because it did not consider the overall latency such as read/write operations of flash chips in the SSD. This paper proposes the clock with hybrid buffer memories (CLOCK-HBM) for a new hybrid buffer policy in the SSD with server computing systems. The CLOCK-HBM constructs new policies based on unique characteristics in both DRAM buffer and NVMs buffer for reducing the number of swapping operations in the SSD. In experimental results, the CLOCK-HBM reduced the number of swapping operations in the SSD by 43.5% on average, compared with LRU, CLOCK, and CLOCK-DNV.

As the artificial intelligence technology has developed recently, researches on chatbots that provide information and contents desired by users through an interactive interface have become active. Since chatbots require a variety of natural language processing technology and domain knowledge including typos and slang, it is currently limited to develop chatbots that can carry on daily conversations in a general-purpose domain. In this study, we propose an artificial intelligence chatbot that can provide real-time public traffic information and route information. The proposed chatbot has an advantage that it can understand the intention and requirements of the user through the conversation on the messenger platform without map application.

Requirements traceability is regarded as one of the important quality attributes in software requirements engineering field. If requirements traceability is guaranteed then we can trace the requirements’ life throughout all the phases, from the customers’ needs in the early stage of the project to requirements specification, deployment, and maintenance phase. This includes not only tracking the development artifacts that accompany the requirements, but also tracking backwards from the development artifacts to the initial customer requirements associated with them. In this paper, especially, we dealt with the traceability between functional requirements and non-functional requirements. Among many Information Retrieval (IR) techniques, we decided to utilize Latent Semantic Indexing (LSI) and Latent Dirichlet Allocation (LDA) in our research. Ultimately, we conducted an experiment on constructing traceability by using two techniques and analyzed the experiment results. And then we provided a comparative study between two IR techniques in constructing traceability between functional requirements and non-functional requirements.

Citation-based article summarization is to create a shortened text for an academic article, reflecting the content of citing sentences which contain other’s thoughts about the target article to be summarized. To deal with the problem, this study introduces an extractive summarization method based on calculating a linear combination of various sentence salience scores, which represent the degrees to which a candidate sentence reflects the content of author’s abstract text, reader’s citing text, and the target article to be summarized. In the current study, salience scores are obtained by computing surface-level textual similarities. Experiments using CL-SciSumm datasets show that the proposed method parallels or outperforms the previous approaches in ROUGE evaluations against SciSumm-2017 human summaries and SciSumm-2016/2017 community summaries.

Data integration technology is one of the key elements in building data warehouses or big data, and is used to combine data from multiple sources and provide an integrated view to users. Traditionally, the performance of data integration uses a handed-code approach or a tool-based approach that utilizes data integration tools such as ETL. There is a debate about which methods are efficient. This study is conducted to give practitioners preparing for a data integration project an insight into how to perform data integration. This paper examines the views of experts on the controversy over the adoption of ETL tools that have been on the agenda of the data integration area for over a decade.

With the popularity of mobile Internet and smart phones, the domestic digital music access platform has entered a period of rapid development. Existing studies in the academic circle have shown that experience has a positive impact on user perception and loyalty. However, the research on the relationship between brand loyalty, user perception and user experience of Internet products has not received much attention. Starting from the brand loyalty theory and user experience theory, this paper explores the mechanism of user experience, user perception and brand loyalty of digital music access platform. Based on the development status of digital music access platform in China, the purpose is to explore how the user experience of the mainstream digital music access platform can affect Usefulness Perception, Epidemic Perception. And to explore how the Usefulness Perception, Epidemic Perception can affect users' brand loyalty. also further explore the role of users' perception in this process to understand the relationship between brand and user experience. In practical operations, 398 formal questionnaires were issued online to collect first-hand data, and reliability analysis, factor analysis, correlation analysis and hypothesis analysis were carried out successively on the data in the later stage. Through research, it is found that the user experience of digital music access platform has a partial significant impact on the perception and loyalty of applications. The visual presentation and emotional feelings of digital music access platform are positively correlated with the perceived usefulness of applications. The visual presentation and emotional feelings of digital music access platform are positively correlated with the perceived popularity of applications. The e perceived usefulness and perceived popularity of the digital music access platform are positively correlated with the loyalty of the application. Through this research, it has certain guiding significance to the promotion of digital music access platform's brand loyalty degree.

With the gradual in-depth use of social elements, music social networking has attracted more and more attention and discussion in the industry. Therefore, starting from the user experience theory and purchase intention theory, this paper explores the mechanism of user social experience and purchase intention in mobile music applications, and adds the mediating role of brand attachment on the basis of literature research. Based on previous studies on user experience measurement of social network and evaluation report of mobile music applications in the industry, and combined with in-depth interviews of users, whether the user experience of mobile music applications, which pays more and more attention to social elements, has an impact on purchase intention or not? What specific social experience can help form purchase intention? Are mediating variables at work? In practice, a total of 398 formal questionnaires were collected to obtain first-hand data. Later, reliability analysis, factor analysis and structural equation model test were carried out successively to verify the hypothesis. According to the results of empirical research, firstly, content experience, atmosphere experience and interactive experience in users' social experience of mobile music applications have a significant impact on brand attachment, secondly, atmosphere experience has a significant impact on purchase intention, and thirdly, brand attachment has a significant impact on users' purchase intention. Fourthly, brand attachment plays an intermediary role in the relationship between users' atmosphere experience and content experience and purchase intention. Based on the above research conclusions, the author puts forward corresponding marketing strategy Suggestions, which have certain guiding significance for mobile music applications to improve users' purchase intention, and have certain reference significance for the development of mobile music applications and the expansion of business model.

In this paper, a classification method of random graph models is proposed and it is based on centralities of the random graphs. Similarity between two random graphs is measured for the classification of random graph models. The similarity between two random graph models    and    is defined by the distance of    and   , where    is a set of random graph         that have the same number of nodes and edges as random graph   . The distance(   ,  ) is obtained by comparing centralities of    and    . Through the computational experiments, we show that it is possible to compare random graph models regardless of the number of vertices or edges of the random graphs. Also, it is possible to identify and classify the properties of the random graph models by measuring and comparing similarities between random graph models.

This paper describes a design for a RF receiver to receive satellite digital audio service. The RF receiver designed in this study is a planar structure that is easy to install on the rooftop of a car and is compact in size. In addition, it can be applied to certain commercial models because it has low noise and high gain characteristics. The impedance bandwidth of antenna is 17.8%(415MHz), and the axial ratio is below 3dB as good properties for the bandwidth of 40MHz which is a satellite digital audio service band. Also, it had a broad radiation beamwidth of 95.41° in H-plane and 117.45° in E-plane. From the results of the field test of satellite digital audio service reception for the RF receiver, it demonstrated good C/N rate(10.2dB).

We investigate the D2D utility maximization in the cellular system. We focus on the non cooperative game theoretic approach to maximize the individual utility. Cellular system's perspective, interference from the D2D links must be limited to protect the cellular users. To accommodate this interference issue, utility function is first defined to control the individual D2D user’s transmit power. More specifically, utility function includes the pricing which limits the individual D2D user's transmit power. Then, non cooperative power game is formulated to maximize the individual utility. Distributed algorithm is proposed to maximize the individual utility, while limiting the interference. Convergence of the proposed distributed algorithm is verified through computer simulation. Also the effect of pricing factor to SIR and interference is provided to show the performance of the proposed distributed algorithm.

In the IoT(Internet of Things) environment, various devices are utilized and applied for different sites. But attackers can access easy to IoT systems, and try to operate DDoS(Distributed Denial-of-Service) attacks. In this paper, Sensor nodes, Cluster heads, and Gateways operates lightweight mutual authentication each others. Since authenticated sensor nodes and cluster heads only send transactions to Gateways, proposed techniques prevent DDoS attacks. In addition, the blockchain system contains secure keys to decrypt data from sensor nodes. Therefore, attackers can not decrypt the data even if the data is eavesdropped.

In this paper, we propose an intelligent marketing service system that can provide custom advertisements and events to both businesses and customers by identifying the location and contents using the ultrasonic signals and feature information in voice signals. We also develop the encoding and decoding algorithm of ultrasonic signals for this system and analyze the performance evaluation results. With the development of the hyper-connected society, the on-line marketing has been activated and is growing in size. Existing store marketing applications have disadvantages that customers have to find out events or promotional materials that the headquarters or stores throughusing the corresponding applications whenever they visit them. To solve these problems, there are attempts to create intelligent marketing tools using GPS technology and voice recognition technology. However, this approach has difficulties in technology development due to accuracy of location and speed of comparison and retrieval of voice recognition technology, and marketing services for customer relation are also much simplified.

In this paper, we propose a new scalable and reliable combat system software in battleship which was developed procedurally in the past. Recently, combat system software is required to change frequently due to addition of new equipment and change of function. To solve those problems, this paper propose how to change combat system software into scalable software using class structure change and design pattern. Simulation results show that our scheme provides better performances and reliability than conventional scheme. Therefore proposed scheme can be efficiently used in Naval combat system.

In this study, a GIS-based park safety assessment index was developed to enable objective park vulnerability assessment through data-based GIS analysis, a safety assessment was conducted by selecting a target site where various parks are operated and applying the park safety assessment index. In addition, a facility management system was developed for efficient management of the park safety assessment to update the park safety and provide a foothold for indirect PPGIS. In the case of the assessment index of the safety rating of the park, it was possible to conclude that the accurate quantitative performance was given to the calculation of the safety grade of the park based on the fact that the facilities are different depending on the environment and the size of the park. In addition, the marking the safety grade of parks, as well as the function to show the safety facilities of parks, a common living area for citizens, the management system is expected to have an impact on promoting the use of parks. In the future, in functions such as reporting of facility failures and verifying civil information are implemented by applying civic group participation programs and crowd-sourcing technologies, it is believed that all facilities as well as parks managed by the local government can be managed more efficiently.

In this paper, we propose to investigate the differences of academic achievement and core competence according to university admission types. Research subjects were 159 nursing students in G city. The tool used in this study was Collegiate Students Essential Skills Assessment developed by the KW University. The 6 areas measured with the tool are: humanities, Humanism, self-directedness, creative competence, practice competence and global competence. The data were analyzed by descriptive statistics, ANOVA, Scheffe’ test and pearson’s correlation coefficient using SPSS WIN 18.0 Program. There were significant differences in core competence according to university admission types. But There were significant differences in academic achievement according to university admission types. And significant positive correlation between academic achievement and core competece was not founded. But significant positive correlation of 6 core competencies were founded. Based on the result of this study, it is possible to serve basic data for establishing better university admission type.

Because military weapons systems for special purposes are small and complex, they are not easy to maintain. Therefore, it is very important to maintain combat strength through quick maintenance in the event of a breakdown. In particular, naval ships are complex weapon systems equipped with various equipment, so other equipment must be considered for maintenance in the event of equipment failure, so that skilled maintenance personnel have a great influence on rapid maintenance. Therefore, in this paper, we analyzed maintenance data of defense equipment maintenance information system through text mining and social network analysis(SNA), and tried to identify the naval ship maintenance expertise. The defense equipment maintenance information system is a system that manages military equipment efficiently. In this study, the data(2,538cases) of some naval ship maintenance teams were analyzed. In detail, we examined the contents of main maintenance and maintenance personnel through text mining(word cloud, word network). Next, social network analysis(collaboration analysis, centrality analysis) was used to confirm the collaboration relationship between maintenance personnel and maintenance expertise. Finally, we compare the results of text mining and social network analysis(SNA) to find out appropriate methods for finding and finding naval ship maintenance expertise.

The purpose of this study is to extract the key words from the list of research subjects related to 'hotel workers' published in recent 10 years(2009～2018) by using the language network analysis method and to confirm the relation between the key words. In this paper, we propose a semantic network analysis that can overcome limitations of longitudinal study, analyze the recent research trends, and widely use as a research model. The results of this study are as follows ; First, in analyzing major key words in the title of 'Hotel Employer' in recent 10 years, the major keyword of job satisfaction(40), special grade(26), organizational commitment(20), emotional labor(19), service(12), restaurant(10), and turnover intention(9). Second, we analyzed the relation of language network among major key words extracted from the study title of 'hotel workers'. Such a research process is expected to grasp the trends of research related to 'hotel workers' and give implications for the future direction of related research.

The purpose of the present study was to investigate the causal relationships between social support, spiritual well-being, and depression among family caregivers caring for the elderly in need of long-term care. Based on previous studies and theoretical backgrounds, a mediation research model including the aforementioned variables was proposed. A total of 383 family caregivers from 25 long-term care facilities in G Metropolitan City were included in the present study and hierarchical regression was used. The primary results were as follows. First, family caregivers’ social support was negatively associated with depression. Second, family caregivers’ social support was positively associated with spiritual well-being. Third, family caregivers’ spiritual well-being was negatively associated with depression. Fourth, social support was positively associated with spiritual well-being, which was related to weaker depression among family caregivers. Finally, theoretical implications of these findings and recommendations for policy and practice were also discussed.

This study aims to analyze the mutual influences between adolescents' multicultural acceptability and school adjustment. Research problems for research are as follows. First, is multicultural acceptability and school adjustment stable over time? Second, what is the longitudinal impact of school adjustment on multicultural acceptability over time? Third, what is the longitudinal impact of multicultural acceptability on school adjustment over time? The results of analyzing the research problems by applying the autoregressive cross-lagged model are as follows. First, the autoregressive model of school adjustment has a significant effect on the future time point and is stable over time. Second, the autoregressive model of multicultural acceptability have a significant effect on the future time point and is stable over time. Third, cross-lagged effect from school adjustment to multicultural acceptability has a statistically significant effect on the multicultural acceptability at a later time, and is stable over time. Fourth, cross-lagged effect from multicultural acceptability to school adjustment was not statistically significant at the time of multicultural acceptability, and there was no change with time. This study is meaningful to provide the theoretical and practical implications by verifying the influence of the three - year term data over time.

The purpose of this study is to analyze the mediating effects of anger level on the effects of middle school students' school adjustment on smartphone addiction. In order to accomplish the purpose of this study, the following research problems were set up. First, what is the relationship between Chinese smartphone addiction, anger level, and school adjustment of Chinese middle school students? Second, what is the effect of smartphone addiction on middle school students' anger level and school adjustment? Third, what is the mediating effect of the level of anger in the process of affecting the school adjustment to smartphone addiction by Chinese middle school students? The subjects of this study were five city schools and seven municipal schools in J-do, among which 450 students were enrolled from April 23 to May 18, 2018. A total of 439 copies were used for the analysis, except for 11 unexplained questionnaires or unfairly responded to the collected questionnaires. The conclusions based on the results of this study are as follows. First, there are negative correlations between the sub-factors of smartphone addiction and the sub-factors of school adjustment. Among them, tolerance is only positively correlated with the peer relationship. The sub-factors of smartphone addiction have negatively correlated with anger expression, anger control, and anger suppression. Second, the effect of sub-factors of smartphone addiction on the level of anger was 3.6%, and the effect on school adjustment was 4.2%. Third, The anger level of the middle school students affected the school adjustment by the smartphone addiction has a partial mediating effect of 0.8%.