• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.6
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• pp.25-35
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• 2006

Radio Frequency identification (RFID) will become an important technology in remotely object identification systems. However, the use of RFID tags may create new threats to the sniな and Privacy of individuals holding RFID tags. These threats bring several problems which are information leakage of a tag, location trace of individuals and impersonation of a tag. Low-cost RFID systems have much restrictions such as the limited computing power, passive power mechanism and low storage space. Therefore, the cost of tag's computation should be considered as an important factor in low-cost RFID systems. We propose an authentication protocol, OHLCAP which requires only one one-way hash function operation and hence is very efficient. Furthermore, our protocol is suitable to distribution database environment. Hence our scheme can be applied to ubiquitous computing environment.

• Journal of Information Processing Systems
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• v.17 no.3
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• pp.489-504
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• 2021

By distributing computing tasks among devices at the edge of networks, edge computing uses virtualization, distributed computing and parallel computing technologies to enable users dynamically obtain computing power, storage space and other services as needed. Applying edge computing architectures to Internet of Vehicles can effectively alleviate the contradiction among the large amount of computing, low delayed vehicle applications, and the limited and uneven resource distribution of vehicles. In this paper, a predictive offloading strategy based on the MEC load state is proposed, which not only considers reducing the delay of calculation results by the RSU multi-hop backhaul, but also reduces the queuing time of tasks at MEC servers. Firstly, the delay factor and the energy consumption factor are introduced according to the characteristics of tasks, and the cost of local execution and offloading to MEC servers for execution are defined. Then, from the perspective of vehicles, the delay preference factor and the energy consumption preference factor are introduced to define the cost of executing a computing task for another computing task. Furthermore, a mathematical optimization model for minimizing the power overhead is constructed with the constraints of time delay and power consumption. Additionally, the simulated annealing algorithm is utilized to solve the optimization model. The simulation results show that this strategy can effectively reduce the system power consumption by shortening the task execution delay. Finally, we can choose whether to offload computing tasks to MEC server for execution according to the size of two costs. This strategy not only meets the requirements of time delay and energy consumption, but also ensures the lowest cost.

• The Korean Journal of Applied Statistics
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• v.35 no.2
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• pp.217-227
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• 2022

Quantile regression is widely used in many fields based on the advantage of providing an efficient tool for examining complex information latent in variables. However, modern large-scale and high-dimensional data makes it very difficult to estimate the quantile regression model due to limitations in terms of computation time and storage space. Divide-and-conquer is a technique that divide the entire data into several sub-datasets that are easy to calculate and then reconstruct the estimates of the entire data using only the summary statistics in each sub-datasets. In this paper, we studied on a variable selection method using Bayes information criteria by applying the divide-and-conquer technique to the penalized quantile regression. When the number of sub-datasets is properly selected, the proposed method is efficient in terms of computational speed, providing consistent results in terms of variable selection as long as classical quantile regression estimates calculated with the entire data. The advantages of the proposed method were confirmed through simulation data and real data analysis.

• Smart Media Journal
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• v.11 no.5
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• pp.56-62
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• 2022

Water reservoir is defined as a storage space to hold and supply filtered water and it's significantly important to manage water level in the water reservoir so as to stabilize water supply by controlling water supply depending on demand. Liquid level sensors have been installed in the water reservoir and the pumps in the booster station facilitated management for optimum water level in the water reservoir. But the incident responses including sensor malfunction and communication breakdown actually count on manager's inspection, which involves risk of accidents. To stabilize draining facility management, this study has come up with AI model that predicts changes in the water level in the water reservoir. Going through simulation in the case of missing data in the water level to verify stability in relation to the field application of the prediction model for water level changes in the reservoir, the comparison of actual change value and predicted value allows to test utility of the model.

• Journal of Aerospace System Engineering
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• v.17 no.4
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• pp.1-9
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• 2023

Recently, as Synthetic Aperture Radar (SAR), communication, and signal surveillance missions of spacecraft have become more advanced, research has been actively conducted on the deployable large mesh antenna system with excellent storage efficiency compared to the deployment area, and light weight. Deployable Mesh antennae are characterized by an increase in the number of Openings Per Inch (OPI), which is a measure of mesh weaving density as the mission frequency band increases, and this OPI change directly affects the thermal optical properties of the mesh antenna, so research on this is required. In this paper, to verify the thermal relationship between the optical properties of the mesh and antenna reflector, thermal sensitivity analysis between the mesh and the antenna reflector is performed by in-orbit thermal analysis with various optical characteristics of the mesh based on existing overseas research cases. In addition, the temperature gradient effect of the mesh reflector is analyzed.

• Journal of Korea Society of Industrial Information Systems
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• v.14 no.2
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• pp.8-15
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• 2009

The need for ASP(Application Service Provider) has evolved from the increasing costs of specialized software that have far exceeded the price rage of small to medium sized businesses. There are a lot of technologies that make ASP possible, and software streaming service is one of them Software streaming is a method for overlapping transmission and execution of stream-enabled software. The stream-enabled software is able to run on a device even while the transmission/streaming of the software may still be in progress. Thus, a user does not have to wait for the completion of the software's download prior to starting to execute the software. In this paper, we suggest the new concept of software streaming system implement using the PageFault Interrupt Routine Hooking. As it is able to efficiently manage application, we do not have to install the entire software. In addition, we can save hardware resources by using it because we load basic binaries without occupying the storage space of the hardware.

• Tunnel and Underground Space
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• v.33 no.4
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• pp.265-280
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• 2023

Water leakage in tunnels is a defect that can affect tunnel stability and the ground movement by changing the stress and pore water pressure of the surrounding ground. Long-term or large-scale water leaks may lead to damage of tunnel structure and the surrounding environment, such as tunnel lining instability and ground surface settlement. The present study numerically investigated the effects of water leakage on the structural stability of a tunnel and the ground behavior. The tunnel was assumed to be under undrained conditions for preventing the inflow of the surrounding water and leaks occurred in the concrete lining after completion of the tunnel construction. A coupled hydro-mechanical analysis using a TOUGH-FLAC simulator developed in Python was conducted for assessing the leakage induced-behavior of the tunnel structure and ground under different conditions of the amount and location of water leak. Additionally, the effect of hydro-mechanical coupling terms on the results of coupled response was investigated and discussed.

• Journal of Industrial Convergence
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• v.21 no.5
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• pp.133-142
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• 2023

In recent years, the problem of academic credential falsification is not simply the manipulation of certificates generated by educational institutions, but also the difficulty of trusting automated relationship verification and verification itself, such as falsely recording completion as graduation while still in school. This is due to the lack of sharing of educational background databases among university institutions and the establishment/operation of independent systems that make it difficult to track educational backgrounds. This study designs and implements an E-AV model for academic credential verification centered on university institutions. It summarizes and stores the linked information on the existing academic background in an encrypted database and implements it with web standard technology considering the compatibility and scalability of the existing system. The results of sample data verification show that it improves safety against forgery and complies with storage space and execution performance. This study aims to contribute to the improvement of online verification services such as academic records management in domestic universities.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.199-201
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• 2021

The Internet of Things (IoT) is a technology that can organically connect people and things without time and space constraints by using communication network technology and sensors, and transmit and receive data in real time. The IoT used in all industrial fields has limitations in terms of storage allocation, such as device size, memory capacity, and data transmission performance, so it is important to manage power consumption to effectively utilize the limited battery capacity. In the prior research, there is a problem in that security is deteriorated instead of improving power efficiency by lightening the security algorithm of the encryption module. In this study, we proposes a low-power security architecture that can utilize high-performance security algorithms in the IoT environment. This can provide high security and power efficiency by using relatively complex security modules in low-power environments by executing security modules only when threat detection is required based on inspection results.

• Journal of Aerospace System Engineering
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• v.17 no.2
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• pp.111-119
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• 2023

Internal storage state, weight data, and weight-centered calculation values for overhead bin can all be seen in this paper's real-time internal status identification system. The suggested system offers such valuable data via a range of sensors, including load cells and switch arrays. The proposed system could locate internal free space, locate the center of gravity, and give real-time visual information. It was developed utilizing an embedded system and the C programming language. These features led to the creation of smart overhead bins and real-time cargo loading monitoring technologies, both of which could one day aid in the creation of a cargo loading automation system.