• Journal of the Korea Society for Simulation
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• v.29 no.3
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• pp.73-82
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• 2020

In the fourth industrial revolution, wireless sensor networks (WSNs) are an important element of collecting and analyzing data in a variety of environments without human intervention. This sensor network is greatly affected by topology and routing protocols. Routing protocols, which affect energy consumption, are executed after deploying sensor nodes. Once built, they are difficult to change. Before the WSN is deployed, a routing protocol is carefully selected in view of various environments and the performance of the protocol is evaluated. In this paper, we propose a model to simulate multiple routing protocols using a discrete event system specification (DEVS). The DEVS-based proposed model simulates various situations without changes and structures of the its model as algorithms of the routing protocols are implemented in its coordinators model. To verify normal behaviors of the proposed model, the number of report delivery and the energy consumption of the sensor network were compared using representative protocols LEACH and Dijkstra. As a result, it was confirmed that the proposed model executes normally in both routing protocols.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1286-1294
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• 2011

This paper reviews the future directions and perspectives on the soil environmental researches in the 21 century. Previously, the principal emphasis of soil environmental researches had put on the enhancement of food and fiber productions. Beside the basic function of soil, however, the societal needs on soil resources in the 21st century have demands for several environmental and social challenges, occurring regionally or globally. Typical global issues with which soil science should deal include food security with increasing agronomic production to meet the exploding world population growth, adaptation and mitigation of climate change, increase of the carbon sequestration, supply of the biomass and bioenergy, securing the water resource and quality, protection of environmental pollution, enhancing the biodiversity and ecosystem health, and developing the sustainable farming/cropping system that improve the use efficiency of water and agricultural resources. These challenges can be solved through the sustainable crop production intensification (SCPI) or plant welfare concept in which soil plays a key role in solving the abovementioned global issues. Through implementation of either concept, soil science can fulfill the goal of the modern agriculture which is the sustainable production of crops while maintaining or enhancing the ecosystem function, quality and health. Therefore, directions of the future soil environmental researches should lie on valuing soil as an ecosystem services, translating research across both temporal and spatial scales, sharing and using data already available for other purposes, incorporating existing and new technologies from other disciplines, collaborating across discipline, and translating soil research into information for stakeholders and end users. Through the outcomes of these approaches, soil can enhance the productivity from the same confined land, increase profitability, conserve natural resource, reduce the negative impact on environment, enhance human nutrition and health, and enhance natural capital and the flow of ecosystem services. Soil is the central dogma, final frontier and new engine for the era of sustainability development in the $21^{st}$ century and thus soil environmental researches should be carried according to this main theme.

• Industry Promotion Research
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• v.6 no.4
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• pp.95-103
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• 2021

Startup enterprises are expanding at an alarming rate in both industrialized and developing countries simultaneously. Many difficulties confront young entrepreneurs in terms of organizational and human resource management. As a result, it is critical to research startup enterprises because they have received little attention from the scientific community. In this study, we solely considered new startup enterprises operating at the small and medium-sized enterprise (SME) level in a developing country (Pakistan). The information was gathered through a survey method from ten businesses located in the metropolitan metropolis of Lahore. The correlation analysis was conducted to determine whether or not the hypothesized relationship between research variables was true. We discovered a positive and statistically significant association between all of the proposed hypotheses. The findings of this study have significant implications for industry, academics, and policymakers.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.3
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• pp.64-72
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• 2021

Manned-unmanned teaming can be a very promising air-to-air combat tactic since it can maximize the advantage of combining human insight with the robustness of the machine. The rapid advances in artificial intelligence and autonomous control technology will speed up the development of manned-unmanned teaming air-to-air combat system. In this paper, we introduce a manned-unmanned teaming air-to-air combat tactic which is composed of a manned aircraft and an UAV. In this tactic, a manned aircraft equipped with radar is functioning both as a sensor to detect the hostile aircraft and as a controller to direct the UAV to engage the hostile aircraft. The UAV equipped with missiles is functioning as an actor to engage the hostile aircraft. We also developed a combat scenario of executing this tactic where the manned-unmanned teaming is engaging a hostile aircraft. The hostile aircraft is equipped with both missiles and radar. To demonstrate the efficiency of the tactic, we run the simulation of the scenario of the tactic. Using the simulation, we found the optimal formation and maneuver for the manned-unmanned teaming where the manned-unmanned teaming can survive while the hostile aircraft is shot-downed. The result of this study can provide an insight to how manned aircraft can collaborate with UAV to carry out air-to-air combat missions.

• Journal of Korea Port Economic Association
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• v.37 no.1
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• pp.121-142
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• 2021

The purpose of this study is to identify environmental factors affecting manpower utilization of container terminals. 300 questionnaires were distributed to employees working in terminal operators in Busan and Gwangyang port. Based on the results of multiple regression analysis, first, it is proved that technology development, organizational culture and social·external environment have a significant impact on manpower utilization of container terminals. Second, this study found that technology development and social·external environment have a significant impact on manpower utilization of container terminals system. Third, it is found that technology development, social·external environment, safety and security change the composition of the workforce between office and field employees. Forth, the number of workforce is expected to gradually decrease due to technology development. Finally, it is found that technology development, organizational culture, social·external environment and terminal operation have a impact on specialization and training system of human resoures.

• Journal of Digital Convergence
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• v.16 no.11
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• pp.137-147
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• 2018

To prepare for and implement policies for the Fourth Industrial Revolution, which is characterized by convergence, super-connectivity, and AI, this study summarized the effects and characteristics of individual technologies on our society and discussed the issues with humanity and social science perspectives. As a result, in terms of AI technology, the issues of job losses, project-type works, basic income and robot taxes, accountability of AI, and algorithm inequality were dealt with. Security, cyber hacking and privacy infringement issues were highlighted in big-data technology. In the part of block-chain and bioengineering, the society of decentralization, the concentration, digital divide, and ethical issues were discussed. On-demand economic aspects highlighted the problems of civil ethics and human commercialization. Lastly, the development of VR is discussed including side effects such as cyber-syndrom, avoidance of reality, and so on.

• Tunnel and Underground Space
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• v.29 no.1
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• pp.52-63
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• 2019

It is highly in demand to establish a bunker-type underground data center to ensure the safety of national critical data, such as financial information and medical information, and prevent those outflow of national important data. In particular, the security of a data center which is a key national structure has become a social issue due to EMP weapon and earthquakes, but data centers in the nation have not been able to deal with it properly. Therefore, it is necessary to develop an underground data center that is safe from human-induced and natural disasters while reducing power costs by utilizing the benefits of underground spaces such as constant temperature and isolation. In this analysis, the status and trends of data centers around the world were analyzed and based on those trend analyses, the research strategy for underground data center were discussed.

• Journal of The Korean Association of Information Education
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• v.23 no.2
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• pp.141-148
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• 2019

We proposed a curriculum that can learn the principle of blockchain by using the gamification which can bring up the interest and concentration of the students by connecting the contents of the class with the game. The proposed method is to educate the blockchain in a game format and to solve the problem that can be easily accessed in everyday life by applying the blockchain. By strengthening the thinking ability of computing, By growing information processing capacity, communication capacity, and community capacity, students can naturally enhance their education capacity. It is expected that the blockchain curriculum using the proposed gamification can be used to improve the information curriculum.

• Journal of Internet Computing and Services
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• v.19 no.6
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• pp.133-145
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• 2018

Medical systems incurred accidents may result in significant damage for human being. Therefore, performing hazard analysis is important for medical system which is to identify hazard for preventing the accidents and minimizing the potential harm. Hazard analysis that is applied medical systems are difficult to apposite selected, because difference of analysis methods and applied development lifecycle is caused by objective of hazard analysis. It is required to select appropriate hazard analysis at concept phase during development lifecycle, owing to basic requirement elicitation to mitigate or prevent hazard based on identified hazard at concept phase. In this paper, hazard analysis methods, PHA and STPA, are compared at concept phase in which both methods have been applied on the medical system. As a result of compared methods, hazard analyst can be selected optimized hazard analysis methods for concept phase of the medical systems.

• Food Science and Industry
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• v.53 no.4
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• pp.410-421
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• 2020

Regarding a long-term strategic plan in the food and agriculture sector, R&D policies and investment trends in major overseas countries are reviewel. The importance of efficient resource management is emphasized along with continuous government support for R&D in the agri-food industry. In response to facing social issues such as climate change, food security, food safety, health, and environment, research and innovation agenda is mainly focused on harmony between economy and environment, human nutrition and health as well as animal and plant health, and an integrated ecosystem approach. Particularly in the food sector, public investment is generally made in food safety, nutrition and health, and private investment for food processing and manufacturing. Public-private collaboration is carried out in order to enhance the efficiency of R&D innovation and development strategies in the agri-food industry.