• Journal of Internet Computing and Services
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• v.20 no.3
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• pp.119-128
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• 2019

This study aims to analyze the research trends on Smart City and to present implications to policy maker, industry professional, and researcher. Cities around globe have undergone the rapid progress in urbanization and the consequent dramatic increase in urban dwellings over the past few decades, and faced many urban problems in such areas as transportation, environment and housing. Cities around the globe are in a hurry to introduce Smart City to pursue a common goal of solving these urban problems and improving the quality of their lives. However, various conceptual approaches to smart city are causing uncertainty in setting policy goals and establishing direction for implementation. The study collected 11,527 papers titled "Smart City(cities)" from the Scopus DB and Springer DB, and then analyze research status, topic, trends based on abstracts and publication date(year) information using the LDA based Topic Modeling approaches. Research topics are classified into three categories(Services, Technologies, and User Perspective) and eight regarding topics. Out of eight topics, citizen-driven innovation is the most frequently referred. Additional topic network analysis reveals that data and privacy/security are the most prevailing topics affecting others. This study is expected to helps understand the trends of Smart City researches and predict the future researches.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.6
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• pp.133-137
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• 2018

Arduino is a small microcomputer that is used in a variety of industry fields and especially is widely used as an open source hardware IoT device. The multi-tasking method of Arduino is divided into super loop timing and RTOS thread method. The super loop timing method is simple and easy to understand. However, when one task is long, it affects the execution of the next task. In addition, RTOS threading has the advantage of being able to run without being influenced by other work time. However, Arduino, a small microcomputer, has a disadvantage in that, when the number of threads increases, the context switching time of the thread causes additional time not included in the super loop timing method have. In this paper, we use Arduino Uno R3 and FreeRTOS to analyze these different features, and the task for the experiment is to send 8000 digital signals to the built-in LED port. If two tasks of the same size are executed, the super loop method executes 3 ms faster than FreeRTOS multitasking. If multiple tasks are executed simultaneously, superloop type task is sequential execution and difference in execution time between first task and last task is large. FreeRTOS method can be executed concurrently, but execution time delay of about 30 ms occurs in context switching time.

• Informatization Policy
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• v.26 no.3
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• pp.69-89
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• 2019

In order to implement smart cities that will become living spaces in the fourth industrial revolution era, detailed privacy information such as residents' living information, buildings and facilities information must be collected and processed in real time. While city functions and convenience for individuals are being facilitated, threats to personal information exposure and leakage are also likely to increase at the same time. Therefore, the design concept for personal information protection should be considered and accordingly reflected from the stages of smart city design, technology development and operation planning of intelligent information (AI) facilities. The results of the analysis show that for activation of smart cities and operation of data-driven cities, the concept of Privacy by Design (PbD) has already been introduced in the institutional, industrial and technological aspects, particularly in the cases of European countries and the US. In order to strengthen the local and global competitiveness of smart cities and the country, Korea also needs to actively deploy PbD as a strategy to secure a data-driven economy, which is the core strategy for smart cities. Therefore, the study suggests policy implications focused on approaches to legislative improvement and technology development support, which reflect the basic properties of PbD as defined in the study.

• Convergence Security Journal
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• v.18 no.1
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• pp.19-31
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• 2018

As the ICT technologies advance, the unprecedently large amount of digital data is created, transferred, stored, and utilized in every industry. With the data scale extension and the applying technologies advancement, the new services emerging from the use of large scale data make our living more convenient and useful. But the cybercrimes such as data forgery and/or change of data generation time are also increasing. For the data security against the cybercrimes, the technology for data integrity and the time verification are necessary. Today, public key based signature technology is the most commonly used. But a lot of costly system resources and the additional infra to manage the certificates and keys for using it make it impractical to use in the large-scale data environment. In this research, a new and far less system resources consuming signature technology for large scale data, based on the Hash Function and Merkle tree, is introduced. An improved method for processing the distributed hash trees is also suggested to mitigate the disruptions by server failures. The prototype system was implemented, and its performance was evaluated. The results show that the technology can be effectively used in a variety of areas like cloud computing, IoT, big data, fin-tech, etc., which produce a large-scale data.

• Design & Manufacturing
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• v.15 no.2
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• pp.23-29
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• 2021

The specific strength of magnesium alloy is four times that of iron and 1.5 times that of aluminum. For this reason, its use is increasing in the transportation industry which is promoting weight reduction. At room temperature, magnesium alloy has low formability due to Hexagonal closed packed (HCP) structure with relatively little slip plane. However, as the molding temperature increases, the formability of the magnesium alloy is greatly improved due to the activation of other additional slip systems, and the flow stress and elongation vary greatly depending on the temperature. In addition, magnesium alloys exhibit asymmetrical behavior, which is different from tensile and compression behavior. In this study, a jig was developed that can measure the plane deformation behavior on the surface of a material in tensile and compression tests of magnesium alloys in warm temperature. A jig was designed to prevent buckling occurring in the compression test by applying a certain pressure to apply it to the tensile and compression tests. And the tensile and compressive behavior of magnesium at each temperature was investigated with the developed jig and DIC equipment. In each experiment, the strain rate condition was set to a quasi-static strain rate of 0.01/s. The transformation temperature is room temperature, 100℃. 150℃, 200℃, 250℃. As a result of the experiment, the flow stress tended to decrease as the temperature increased. The maximum stress decreased by 60% at 250 degrees compared to room temperature. Particularly, work softening occurred above 150 degrees, which is the recrystallization temperature of the magnesium alloy. The elongation also tended to increase as the deformation temperature increased and increased by 60% at 250 degrees compared to room temperature. In the compression experiment, it was confirmed that the maximum stress decreased as the temperature increased.

• Journal of Korea Port Economic Association
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• v.38 no.1
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• pp.31-47
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• 2022

While the ship finance industry has long been struggling with diminishing involvements from the private sector, government-run banks have consistently increased their presence in maritime finance. To address such concerns, this research conceptually explores the creation of blockchain technology-driven security token offering (STO) platforms. To suggest a sound platform model, this piece first examines key design principles. Based on the integral perspective on the digital platform, this paper exhibits three core design principles to create a virtuous platform ecosystem, then sets out STO platform design guidelines. This paper further explores an STO platform model by considering conventional ship finance systems and practices in Korea. The STO platform has three main effects; 1) the wider availability of STOs can enlarge both the scope and size of ship finance users, 2) the activation of security token transactions leads to an increase in participation, and 3) possibilities to create complementary innovative financial services can further encourage the participation of private investors. The STO ecosystem may contribute to the shipping, shipbuilding, and ship finance industries by enhancing its attractiveness to the general public and by creating positive externalities for Busan as a maritime finance center.

• Journal of Korea Society of Industrial Information Systems
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• v.28 no.1
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• pp.57-69
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• 2023

In a situation where digital transformation using artificial intelligence is active around the world, the growth of domestic AI companies or AI industrial ecosystems is slow. Where a large amount of government funds related to AI are being invested to overcome the difficult economic situation, systematic research on the effect is insufficient. So, this study aimed to examine the policy effectiveness of the government artificial intelligence solution voucher support project for small and medium-sized enterprises (SMEs) using Propensity Score Matching (PSM) and Difference-in-Differences (DID) on the financial performance of beneficiary companies. For empirical analysis, PSM-DID analysis was performed using sales performance since 2019 for 461 companies with a history of voucher support among the AI SMEs data released by the National IT Industry Promotion Agency. As a result of the analysis, the beneficiary companies' asset growth, salary, and R&D expenses increased overall after government support, and no significant contribution could be confirmed in terms of profits. This study suggests that the voucher policy business directly contributed to the company's growth in the short term, but it requires a certain period of time to generate profits.

• The Journal of the Korea Contents Association
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• v.22 no.9
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• pp.179-193
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• 2022

Amid the explosive growth of various metaverse platforms, there is no unified indicator to measure, analyze, and evaluate based on customer experience. Therefore, the usability evaluation factors in metaverse were identified through a heuristic methodology and literature review, to evaluate the metaverse, a two-to three-dimensional virtual world platform. A measurable system was established by subdividing 20 items in 5 fields, including user control, information structure, design and content, and usage environment, derived through Delphi technique. Based on this, after experiencing the actual contents of major metaverse platforms such as Roblox and Zepeto, usability was evaluated and comparative verification was conducted. As a result, it was estimated that metaverse user experience could be improved as its utility was derived relatively high in terms of user control and content. This study constitutes a theoretical contribution by extending the usability evaluation system, which has been widely used in the field of service design, to the fields of extended reality and mixed reality. At the same time, it has practical key findings of providing basic judgment standards to stakeholders in the metaverse field, as well as policy implications for digital capability enhancement and industry revitalization.

• Journal of the Korean Society of Safety
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• v.37 no.4
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• pp.120-128
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• 2022

Printed circuit boards (PCBs) are a basic component in the electronics industry and are widely used in nearly all electronic products, such as mobile phones, tablet computers, and digital cameras, as well as in electric equipment. PCB manufacturing involves the use of many chemicals and chemical processes and therefore has more risks than other manufacturing sectors. This study aims to identify the causes of possible accidents during PCB manufacturing through risk assessment, develop and implement safety measures, and evaluate the effectiveness of these measures. Note that the safety measures developed to mitigate the risks of a certain process were also implemented for other similar processes. The risk assessments conducted over seven years, from 2015 to 2021, at a PCB manufacturing company identified 361 hazardous processes. Between 2016 and 2019, 41-56 hazardous processes were identified per year; such processes decreased to fewer than 20 per year after 2020. Application of the risk assessment results to the improvement of the hazardous processes with the similar characteristics seems to be effective in decreasing the risks. Equipment-related factors such as lack of appropriate maintenance, low work standards, and defective protection devices were responsible for 59.8% of all possible accidents. Because PCB manufacturing involves many chemicals, skin contact with hazardous substances, electric shock, fire, and explosion were the most common types of possible accidents (81.7%). In total, 505 safety measures were implemented, including 157 related to purchase and improvement of equipment and devices for safety (31.1%), 147 related to the installation/modification of fire prevention facilities (29.1%), and 69 related to the use of standard electrical appliances (13.7%). Risk assessment conducted after implementing the safety measures showed that these measures significantly decreased risk; 247 processes (68.4%) had a risk level of 3, corresponding to "very low," and 114 processes (31.6%) showed a risk level of 4, corresponding to "low." In particular, risk assessment of 104 processes with risk scores of 12 and 10 other processes with risk score of 16 showed that the risk decreased to 4 after implementing the safety measures. Thus, implementing these measures in similar manufacturing sectors that involve chemical processes can mitigate risk.

• Journal of Service Research and Studies
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• v.12 no.2
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• pp.80-93
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• 2022

This study is a study on a methodology that can extract various factors that affect purchase and use of products/services from the consumer's point of view through previous studies, and analyze the types and tendencies of consumers according to age and gender. To this end, we quantify factors in terms of general personal propensity, consumption influence, consumption decision, etc. to check the consistency of data, and based on these studies, we conduct research to suggest and prove data analysis methodologies of consumer types that are meaningful from the perspectives of startups and SMEs. did As a result, it was confirmed through cross-validation that there is a correlation between the three main factors assumed for data analysis from the consumer's point of view, the general tendency, the general consumption tendency, and the factors influencing the consumption decision. verified. This study presented a data analysis methodology and a framework for consumer data analysis from the consumer's point of view. In the current data analysis trend, where digital infrastructure develops exponentially and seeks ways to project individual preferences, this data analysis perspective can be a valid insight.