• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.3
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• pp.465-475
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• 2022

Due to the impact of COVID-19, people are paying attention to convenience and health, and the use of IoT devices to help them is increasing. In order to embed a lightweight security element in IoT devices that need to handle sensitive information even with limited resources, the development of a lightweight S-box is essential. Until 2021, it was common to develop a lightweight 4-bit S-box by a heuristic method, and to develop an extended structure or repeat the same operation for a larger size lightweight S-box. However, in January 2022, a paper that proposed a heuristic algorithm to find an 8-bit S-box with better differential uniformity and linearity than the S-box generated with an MISTY extended structure, although non-bijective, was published [1]. The heuristic algorithm proposed in this paper generates an S-box by adding AND operations one by one. Whenever an AND operation is added, they use a method that pre-removes the S-box for which the calculated differential uniformity does not reach the desired criterion. In this paper, we improve the performance of this heuristic algorithm. By increasing the amount of pre-removal using not only differential uniformity but also other differential property, and adding a process of calculating linearity for pre-removing, it is possible to satisfy not only differential security but also linear security.

• Journal of Science Education
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• v.46 no.1
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• pp.40-52
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• 2022

Daily science classes, which have been continued as part of the spread of participatory science culture, has taken the lead in popularizing science as an effective out-of-school experiential and research activity. However, due to the recent COVID-19 situation, daily science classes have also become an environment in which there is no choice but to switch to non-face-to-face or to combine face-to-face and non-face-to-face education. Therefore, in this study, we examine how elementary school students participating in the non-face-to-face daily science class program change their usual fields of interest, perception of science and technology, interest about science, and scientific competency. In addition, the educational effectiveness of the non-face-to-face daily science class improved by comparing the differences in perceptions of students and parents, and future operation plans were sought. As a result of the study, after participating in the non-face-to-face daily science class program, students' interest in science and technology development, future technology, environmental pollution, and social media increased, and their interest in games decreased. Also, students' interest in science and technology activities, interest in science, and scientific competency also increased. This shows that non-face-to-face daily science class education is effective. Therefore, it was suggested that it is necessary to diversify the learning topics and content levels of the daily science class program, to expand the opportunities of non-face-to-face science education for underprivileged learners, and to develop and share science content using the latest media.

• Journal of Korea Society of Industrial Information Systems
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• v.27 no.3
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• pp.29-46
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• 2022

COVID-19 has radically changed the behavior of members of society for exchange. In particular, the strong contagiousness of the virus is increasing networking on online platforms while reducing people's networking in the real world. Recently, the metaverse, which strengthened the presence based on 3D technology, is attracting attention from members of society such as individuals and companies. We present a method to improve metaverse utilization from the perspective of organizations and employees who have introduced metaverse for work. In other words, we check the effect of metaverse social function and telepresence on the employee's intention to offer support by improving the trust of the metaverse participants. We obtained samples through questionnaires targeting employees of organizations that introduced metaverse to their work, and verified the research hypothesis by applying the structural equation model. As a result, social interactivity, reciprocal favor, and telepresence of metaverse partially affected metaverse trust (platform, peer, organization), and metaverse trust increased the intention to offer support. Our study suggests a strategic direction to improve the metaverse utilization and exchange level of employees of organizations who want to use the metaverse for business.

• Journal of the Korea Institute of Building Construction
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• v.22 no.3
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• pp.305-316
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• 2022

Domestic construction companies have difficulty in establishing strategies when entering overseas markets because they do not have an overseas construction economic sentiment index to refer to for data on overseas construction prospects. Considering that the fluctuation of overseas construction orders over the past decade has been substantial and large companies and SMEs are actively advancing overseas, this study developed an evaluation model for an overseas construction business sentiment index to grasp the economic experience of overseas construction companies. In 2021 Korean companies earned 30.6 billion in overseas construction contracts, 87% the level of the previous year, despite difficulties such as COVID-19 and low oil prices, thanks to efforts by construction companies to strengthen their strategies for entry, such as regional diversification, and government support for winning orders. Since the overseas construction industry fluctuates greatly due to changes in the international environment, it is necessary to investigate and analyze the economic sentiment index of overseas construction companies. In particular, despite the increase in overseas expansion of small and medium-sized construction companies and engineering companies, the provision of information on the overseas construction market sentiment index is insufficient, limiting the establishment of strategies for overseas construction expansion. Therefore, this study intends to develop an overseas construction market sentiment index model that can understand the economic sentiment of overseas construction companies, provide a forecast for overseas construction, and use it to establish overseas construction strategies and policies.

• Journal of Navigation and Port Research
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• v.46 no.3
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• pp.289-296
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• 2022

The purpose of this study was to investigate the inter-correlation between crude oil prices and Dry Bulk Freight rates. Eco-friendly shipping fuels has being actively developed to reduce carbon emission. However, carbon neutrality will take longer than anticipated in terms of the present development process. Because of OVID-19 and the Russian invasion of Ukraine, crude oil price fluctuation has been exacerbated. So we must examine the impact on Dry Bulk Freight rates the oil prices have had, because oil prices play a major role in shipping fuels. By using the VAR (Vector Autoregressive) model with monthly data of crude oil prices (Brent, Dubai and WTI) and Dry Bulk Freight rates (BDI, BCI and (BP I) 2008.10~2022.02, the empirical analysis documents that the oil prices have an impact on Dry bulk Freight rates. From the analysis of the forecast error variance decomposition, WTI has the largest explanatory relationship with the BDI and Dubai ranks seoond, Brent ranks third. In conclusion, WTI and Dubai have the largest impact on the BDI, while there are some differences according to the ship-type.

• Journal of the Korea Society of Computer and Information
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• v.27 no.7
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• pp.115-124
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• 2022

The purpose of this study is to analyze and present keywords, trends, and language networks of keywords for each year of the pedagogical exam of the secondary teacher's employment exam for the 2019~2022 school year. The main research methods were text mining technique and language network analysis method, and analysis programs were KrKwic, Wordcloud Maker, Ucinet6, NetDraw, etc. The research results are as follows; First, keywords such as teacher, student, curriculum, class, and evaluation appeared in the top rankings, and keywords (online, wiki, discussion ceremony, information, etc.) that reflect the recent online class progress in the current COVID-19 situation also tended to appear. The keywords with high frequency of occurrence in the four-year integrated text were student(44), teacher(39), class(27), school(18), curriculum(16), online(10), and discussion method(8). Second, the overall language network of the keywords with high frequency of 4 years showed a significant level of density(0.566), total number of links(492), and average degree of links(16.4). The degree centrality was found in the order of teacher(199.0), class(197.0), student(185.0), and school(150.0). Betweenness centrality was found in the order of teacher(30.859), class(18.956), student(16.054), and school (15.745). It is expected that the results of this study will serve as data to be considered for preparatory teachers, institutions and related persons, and teachers and administrators of secondary school teacher training institutions.

• Journal of Korea Entertainment Industry Association
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• v.15 no.2
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• pp.83-97
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• 2021

This study started with curiosity about theatre without its three elements and would reveal its possibility through performance and experiment and promote the expansion of each element and the development of a new form at the same time. After the occurrence of COVID-19, theatre has come up against a big limitation of contact-free, untact communication due to its inherent characteristic of 'presence.' For the survival of theatre in the rapidly changing world, it is desperately necessary to check the existing performance method and to be concerned about its development for the future. Thus, this researcher started from a more fundamental exploration of theatre focused on an "experiment of theatre without its three elements" and would sort out the three elements (actors, audience, and a play) from a macroscopic perspective. Also, the researcher would investigate the impacts of these elements on the performance and the possibility of theatre even after removing the elements through performance and experiment. This study consists of one performance and two experiments and is based on the interviews and progress details conducted by the planner and experimenter and the survey with the experiment participants. The significance of this study is its reflection on the essence of the genre, theatre, and the roles of all elements constituting that, not from a narrow perspective that would simply define the concepts of the elements but through the expansion and change of them. Furthermore, hopefully, it will be connected to the discovery of a new theatrical format that has not been considered through its combination with another genre.

• Land and Housing Review
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• v.13 no.3
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• pp.93-106
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• 2022

Ventilation plays an important role in controlling indoor air quality. Due to the recent spread of infectious diseases such as COVID-19 and with people spending more time indoors, there's been increased attention on the importance of ventilation performance. In many countries, ventilation is regulated by airflow rates and the number of air changes per hour (ACH). However, airflow rates and ACH alone do not provide an accurate account of actual indoor pollutant removal and ventilation uniformity in a space. This study looked into the ventilation performance of an actual residential unit using several sampling points instead of basing it off of airflow and air change rates. Literature review was used to derive relevant influencing factors and the tracer gas dilution method was used for the field test. The study measured air velocity, age of air, and ventilation efficiency at several locations and compared them to the average value at the center of the test space to determine the differences in ventilation performance at the selected measurement points. The study showed that different sampling locations resulted in different ventilation values. Findings of this study will be used to develop an experimental procedure for evaluating indoor ventilation performance of actual residential spaces.

• Journal of Industrial Convergence
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• v.20 no.10
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• pp.87-94
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• 2022

This paper seeks to raise inflection points of battery manufacturing bases in Korea in the V4 region through the reorganization of new industrial technologies in accordance with ESG. As a result, the global supply chain market is cut off. The Russian-Ukraine war and the U.S.-China hegemony are competing in the economic crisis caused by COVID-19. It is showing diversification of new suppliers in an environment where mineral, grain procurement, gas, and even wheat imports from China and Russia are not possible. As a protective glocal, this area is used as a buffer zone(Pro-Russia, Hungary). to an isolated zone(anti-Russia, Poland) by war. In this paper, economic growth is expected to slow further due to the EU tapering period and high inflation in world countries. Due to these changes, the conversion of new tech industry and the contraction of Germany's structure due to energy supply may lose the driving force for economic growth over the past 20 years. This is caused by market disconnection(chasm) in the nominal indicators in this area. On the other hand, Korea should actively develop into the V4 area as an energy generation export (nuclear and electric hydrogen generation) area as a bypass development supply area due to the imbalance in the supply chain of rare earth materials that combines AI. By linking this industry, the energy platform can be scaled up and reliable supply technology (next generation BT, recycling technology) in diversification can be formed in countries around the world. This paper proves that in order to overcome the market chasm caused by the industries connection, new energy development and platform size can be achieved and reliable supply technology (next-generation battery and recycling technology, Low-cost LFP) can be diversified in each country.

• Journal of Korea Port Economic Association
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• v.38 no.3
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• pp.151-164
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• 2022

According to the "2021 Trade Statistics" released by the Korea Customs Service, the number of domestic export companies has decreased by 2,400 since COVID-19, and the number of importers has increased by 10,000. Exporting companies are making a great contribution to the economic development of Korea along with the creation of domestic jobs. At a time when the logistics environment changes rapidly, there are insufficient papers analyzing the impact of eco-friendly logistics strategies of domestic exporters on logistics performance. In order for exporting companies to continue to have global competitiveness and improve logistics performance, it is necessary to analyze the impact of eco-friendly logistics strategies on the logistics performance of exporting companies. The purpose of this study is to analyze the effect of eco-friendly logistics strategies of domestic export companies on logistics performance. The eco-friendly logistics strategy is divided into an internal strategy and a supply chain management strategy. As a result of the analysis, it was analyzed that the internal strategy has a positive effect on the logistics performance of exporting companies, and the supply chain management strategy has a positive effect on the logistics performance of exporting companies. As such, it was analyzed that the eco-friendly logistics strategy of exporting companies is an important resource for companies and serves as the basis for improving the logistics performance of companies.