• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.3
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• pp.233-241
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• 2021

As increasing the feasibility of the eVTOL UAM(electric vertical take-off and landing urban air mobility), numerous corporations and laboratories are conducting researches. In the aircraft development process, estimating the cost of the aircraft is essential part in terms of budgeting and commercial viability analysis. However, it is difficult to predict the cost of an eVTOL UAM owing to various configurations and little open cost information. This paper presents a novel method to predict the vehicle cost of various eVTOL configurations by modifying previous studies of the aircraft cost estimation. A vehicle cost of Wisk Cora is calculated by the presented method as an example to illuminate the method. The method is indirectly validated by comparing the vehicle costs of six representative eVTOL aircraft with those from the UAM study reports.

• KIPS Transactions on Software and Data Engineering
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• v.10 no.6
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• pp.201-210
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• 2021

Navigation Software for the various weapon systems has common functionalities which give the possibility of common use among them. SPL(Software Product Line) framework of the navigation software for weapon system refers to developing a standardized navigation software platform from common functionalities of navigation software, managing the standardized navigation software platform, and developing weapon system navigation software such as navigation software for missile, UAV(Unmanned Air Vehicle), submarine, and etc. from the standardized navigation software platform. In this paper, we propose SPL based navigation software development process, Integrated Development Environment and operational concept of SPL framework. The operational concept will be defined by specifying the role of every stake holders and their activity scenario. The Operational concept would be referenced to implement SPL for other domain through using with detail implementation guide.

• Journal of the Korea Society of Computer and Information
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• v.27 no.3
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• pp.149-155
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• 2022

The view of not fully denying the application of accomplice regulations to non-punishable opponents has fallen into a formal and logical circular argument that only provides formal grounds for non-punishment and has failed to provide practical grounds. In addition, it can be said that it has a criminal policy problem contrary to the legal sentiment of the general public by not punishing the active government travel activities of non-punishable accomplices. Therefore, in order to solve this problem, it is necessary to respect the legislator's intention that general non-punishment accomplices can be punished if they exceed the 'minimum government travel commission'. Therefore, if an unpunishable accomplice acts at least within the act required to realize the constituent requirements, the application of the accomplice regulations shall be excluded, and the accomplice regulations shall be applied only if they exceed that extent. In addition, if the indispensable counterparty is a protected person or has no responsibility (possibility of expectation), it can be said that it has provided a practical basis for the inability to punish, so it can be understood as impossible to punish. This interpretation method is thought to be able to present concrete validity in marginal cases where the counterparty is more responsible by substantially presenting the basis for an unpunishable accomplice.

• Journal of Internet Computing and Services
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• v.23 no.4
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• pp.95-107
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• 2022

With the rapid development of Internet of Things sensor devices and big data processing techniques, Internet of Things sensor-based information systems have been applied in various industries. Depending on the industry in which the information systems are applied, the accuracy of the information derived can affect the industry's efficiency and safety. Therefore, security techniques that protect sensing data from security attacks and enable information systems to derive accurate information are essential. In this paper, we examine security threats targeting each processing step of an Internet of Things sensor-based information system and propose security mechanisms for each security threat. Furthermore, we present an Internet of Things sensor-based information system structure that is robust to security attacks by integrating the proposed security mechanisms. In the proposed system, by applying lightweight security techniques such as a lightweight encryption algorithm and obfuscation-based data validation, security can be secured with minimal processing delay even in low-power and low-performance IoT sensor devices. Finally, we demonstrate the feasibility of the proposed system by implementing and performance evaluating each security mechanism.

• The Journal of the Korea Contents Association
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• v.21 no.11
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• pp.268-280
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• 2021

This study analysed the narrative strategies in TV drama utilized in order to support the recent feminism movements. The analysis revealed that this TV drama breaks away from the clichéd patriarchal drama series. It portrays the main characters are not the sons but the two daughters-in-law, and represents the women challenging the order of the patriarchy, and resolving the issues. In this drama, men's power was removed and female agents were held up to ridicule. In addition, it eradicates the traditional female conflict structures and creates a strong bond between the females. With this storyline, TV series concludes with two achievements. One, the stepmother and the mother co-parent the child instead of the father, suggests that a non-blood related matriarchal family is possible. Two, the heir to the chaebol family, which is traditionally a patrilineal structure, is not the oldest son or the immoral son, but the lesbian daughter-in-law, overturning the idea of heteronormativity that is dominant in the patriarchal system.

• Korean Journal of Optics and Photonics
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• v.33 no.3
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• pp.106-112
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• 2022

A two-dimensional optical code division multiple access (OCDMA) encoder/decoder, which is composed of add/drop filters and all-pass filters for delay operation, is proposed. An example design is presented, and its feasibility is illustrated through numerical simulations. The chip area of the proposed OCDMA encoder/decoder could be about one-third that of a previous OCDMA device employing delay waveguides. Its performance is numerically investigated using the transfer-matrix method combined with the fast Fourier transform. The autocorrelation peak level over the maximum cross-correlation level for incorrect wavelength hopping and spectral phase code combinations is greater than 3 at the center of the correctly decoded pulse, which assures a bit error rate lower than 10^-3, corresponding to the forward error-correction limit.

• Journal of Internet Computing and Services
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• v.22 no.6
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• pp.151-162
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• 2021

Steganography is an advanced technique that hides secret messages by transforming them into subtle noise and spreading them within multimedia files such as images, video and audio. This technology has been exploited in a variety of espionage and cyber attacks. SNS messenger is an attractive SNS Service platform for sending and receiving multimedia files, which is the main medium of steganography. In this study, we proposed two noble steganography communication techniques that guarantee the complete reception rate through the use of thumbnail images in the SNS messenger environment. In addition, the feasibility was verified through implementation and testing of the proposed techniques in a real environment using KakaoTalk, a representative SNS messenger in south korea. By proposing new steganography methods in this study, we re-evaluate the risk of the steganography methods and promoted follow-up studies on the corresponding defense techniques.

• 지역과문화
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• v.7 no.1
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• pp.27-57
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• 2020

This study focuses on the culture-based revitalization strategy in creative rural areas. To this end, we first summarized the concept of creative village, which has been discussed in Japan and the West. Also, based on the relationship between them, we proposed a revitalization model of creative villages through the culture and arts. In this process, the concept and relationships were examined in detail through the example of Miryang Theater Village in Miryang. In addition, this study analyzed the problems of Miryang Theater Village and applied it to the concept of creative village and suggested an alternative. Through this process, we reconsidered the meaning and possibility of cultural arts in the creative village. And, it was confirmed that the cultural arts could be realized through the balance and organic linkage between the elements of creative villages in order to localize them in combination with the regional specificity of rural areas.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.9
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• pp.1347-1356
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• 2022

In this paper, we investigate the properties of CoGe thin film-based galvanic cells as a function of their dimension (cell length, width, etc.) and show their application as sensors to Arduino-based IoT sensor networks to detect water contact. Because these CoGe thin film-based galvanic cells do not require mechanical strains or temperature gradients unlike piezoelectric and thermoelectric energy harvesters, we think that these thin film-based galvanic cells are more suitable for self-powered sensor networks demanding sustainable and robust energy harvesters. In the past, a sputter-deposited CoGe thin film has not been intensively investigated for energy harvesting appilcations. Thus, in this study, we perform a feasibility study of galvanic cells composed of a sputter-deposited CoGe thin film to see if they can be applied as potential self-powered sensors. We believe that this paper will be of great help in developing even more enhanced sensor networks.

• Membrane Journal
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• v.33 no.4
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• pp.168-180
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• 2023

H₂ generation from renewable sources is crucial for ensuring sustainable production of energy. One approach to achieve this goal is biohydrogen production by utilizing renewable resources such as biomass and microorganisms. In contrast to commercial methods, biohydrogen production needs ambient temperature and pressure, thereby requiring less energy and cost. Biohydrogen production can reduce greenhouse gas emissions, particularly the emission of carbon dioxide (CO₂). However, it is also associated with significant challenges, including low hydrogen yields, hydrodynamic issues in bioreactors, and the need for H₂ separation and purification methods to obtain high-purity H₂. Various technologies have been developed for hydrogen separation and purification, including cryogenic distillation, pressure-swing adsorption, absorption, and membrane technology. This review addresses important experimental developments in dense polymeric membranes for biohydrogen purification.