• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.4
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• pp.13-26
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• 2006

RFID technology is evaluated as one of core technologies for ubiquitous environment, because of its various characteristics which barcode systems don't have. However, RFID systems have consumer's privacy infringement problems, such like information leakage and location tracing. We need RFID privacy protection protocols, that satisfy three essential security requirements; confidentiality, indistinguishability and forward security, in order to protect consumer's privacy perfectly. The most secure protocol, that satisfies all of the three essential security requirements, among existing protocols, is the hash-chain based protocol that Ohkubo proposed. Unfortunately this protocol has a big disadvantage that it takes very long time to identify a tag in the back-end server. In this paper, we propose a scheme to keep security just as it is and to reduce computation time for identifying a tag in back-end server. The proposed scheme shows the results that the identification time in back-end server is reduced considerably compared to the original scheme of Ohkubo protocol.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.4
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• pp.29-39
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• 2009

In order to respond against worms which are malicious programs automatically spreading across communication networks, worm detection approach by generating signatures resulting from analyzing worm-related packets is being mostly used. However, to avoid such signature-based detection techniques, usage of exploits employing mutated polymorphic types are becoming more prevalent. In this paper, we propose a novel static analysis approach for detecting the decryption routine of polymorphic exploit code, Our approach detects a code routine for performing the decryption of the encrypted original code which are contained with the polymorphic exploit code within the network flows. The experiment results show that our approach can detect polymorphic exploit codes in which the static analysis resistant techniques are used. It is also revealed that our approach is more efficient than the emulation-based approach in the processing performance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.12
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• pp.4682-4705
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• 2020

The Unmanned Aerial Vehicles (UAV) networks consisting of low-cost UAVs are very vulnerable to smart jammers that can choose their jamming policies based on the ongoing communication policies accordingly. In this article, we propose a novel cloud and edge-aided mobile communication scheme for low-cost UAV network against smart jamming. The challenge of this problem is to design a communication scheme that not only meets the requirements of defending against smart jamming attack, but also can be deployed on low-cost UAV platforms. In addition, related studies neglect the problem of decision-making algorithm failure caused by intermittent ground-to-air communication. In this scheme, we use the policy network deployed on the cloud and edge servers to generate an emergency policy tables, and regularly update the generated policy table to the UAVs to solve the decision-making problem when communications are interrupted. In the operation of this communication scheme, UAVs need to offload massive computing tasks to the cloud or the edge servers. In order to prevent these computing tasks from being offloaded to a single computing resource, we deployed a lightweight game algorithm to ensure that the three types of computing resources, namely local, edge and cloud, can maximize their effectiveness. The simulation results show that our communication scheme has only a small decrease in the SINR of UAVs network in the case of momentary communication interruption, and the SINR performance of our algorithm is higher than that of the original Q-learning algorithm.

• Journal of Convergence for Information Technology
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• v.11 no.6
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• pp.146-153
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• 2021

Recently, research on perovskite semiconductor materials has been performed, and the evaluation of properties using surface treatment for this material is the basis for subsequent studies. We studied the results of surface treatment of perovskite thin films exposed to air for about 6 months by generating oxygen plasma with an atmospheric pressure plasma equipment. The reason for exposure for 6 months is that the perovskite thin film is made of organic and inorganic substances, so when exposed to air, the surface changes through reaction with oxygen or water vapor. Therefore, this change is to investigate whether it is possible to restore the original film. The surface shape and the ratio of elements were analyzed by varying the process time from 1 s to 1200 s in an oxygen plasma atmosphere. It was found that the crystal grains change over a process time of 5 s or more. In order to maintain the properties of the deposited film, it is the optimal process condition between 2 s and 5 s.

• Journal of the Korean Institute of Rural Architecture
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• v.23 no.2
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• pp.1-8
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• 2021

The aim of this study is to find what architectural restoration and street-scaping conservation of early settlement in Virginia, which have processed on the style of 18th centuries. One of the settlements in Virginia was Williamsburg that located in the high land between Jamestown and Yorktown. In 1698, the capital of Virginia was moved from Jamestown for the safer environment. At that time they constructed the town like a small urban that had a straight-lined Duke Glocester Street, Georgian style buildings, and landscapes of 18th centuries. Before 1928 the village was flown into ruins, but Rector of the church, Dr. W.A.R. Goodwin, understood the value of reservation to restore the village as colonial architectural style that has an original figure. John Rockefeller Jr. has taken part in his restoration of colonial style of architecture and culture. This paper surveyed nine cases of buildings and srtreet-scape on Duke Glocester Street. Most of the buildings on the street have a proposition, balance, and equipment of Georgian architectural facade in 18th centuries. The conclusion has three points. First, the Williamsburg has been reserved as an early colonial settlement through the restoration of architecture and street-scape design. Second, main architectural style is a Georgian form that has a balance, proportion, and simplicity of facade. Also new buildings and additions of architecture have to keep 'Design Review Guideline of Colonial Williamsburg' in order to contribute the existing colonial buildings. Third, the main street-scape, Duke Glocester Street shows Georgian architecture and cultural life pattern with tradition.

• KIPS Transactions on Software and Data Engineering
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• v.10 no.3
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• pp.79-84
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• 2021

A feature extraction method capable of reflecting features well while mainaining the properties of data is required in order to process high-dimensional data. The principal component analysis method that converts high-level data into low-dimensional data and express high-dimensional data with fewer variables than the original data is a representative method for feature extraction of data. In this study, we propose a principal component analysis method based on adaptive correlation when selecting principal component variables in principal component analysis for data feature extraction when the data is high-dimensional. The proposed method analyzes the principal components of the data by adaptively reflecting the correlation based on the correlation between the input data. I want to exclude them from the candidate list. It is intended to analyze the principal component hierarchy by the eigen-vector coefficient value, to prevent the selection of the principal component with a low hierarchy, and to minimize the occurrence of data duplication inducing data bias through correlation analysis. Through this, we propose a method of selecting a well-presented principal component variable that represents the characteristics of actual data by reducing the influence of data bias when selecting the principal component variable.

• Journal of Korean Society of Archives and Records Management
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• v.21 no.1
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• pp.211-230
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• 2021

This study aims to design folk song metadata based on the OAIS reference model for the folk songs' preservation and permanent use. Thus, the folk songs' general characteristics were investigated by researching literature and related technical standards. The type of records, the methods and standards for long-term storage of records, OAIS reference models, and each package's metadata elements were identified through opinions from the popular songs' creators and researchers. The results awere that first, folk songs were created for social transformation, serving as a cultural heritage different from popular songs given their noncommercial quality. Second, the types of folk song records were identified, and the long-term preservation system suitable for the types of records was based on the OAIS reference model. Third, the metadata were edited, and the OIS reference model was applied such that respect was given to the folk songs' characteristics, context, and original order. Fourth and last, information package metadata elements matching the folk songs' records were derived and applied to the representative Korean folk song, "The March for Being."

• Journal of Positioning, Navigation, and Timing
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• v.9 no.4
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• pp.397-403
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• 2020

In order to synchronize a remote system time to the reference time like Coordinated Universal Time (UTC), it is required to compare the time difference between the two clocks. The time comparison data may have some outliers and the time synchronization performance can be significantly degraded if the outliers are not removed. Therefore, it is required to employ an effective outlier detection algorithm for keeping high accurate system time. In this paper, an outlier detection method is presented for the time difference data of GNSS time transfer receivers. The time difference data between the system time and the GNSS usually have slopes because the remote system clock is under free running until synchronized to the reference clock time. For investigating the outlier detection performance of the proposed algorithm, simulations are performed by using the time difference data of a GNSS time transfer receiver corrected to a free running Cesium clock with intentionally inserted outliers. From the simulation, it is investigated that the proposed algorithm can effectively detect the inserted outliers while conventional methods such as modified Z-score and adjusted boxplot cannot. Furthermore, it is also observed that the synchronization performance can be degraded to more than 15% with 20 outliers compared to that of original data without outliers.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.4
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• pp.32-42
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• 2021

The printing process can have to print various colors with a limited capacity of printing facility such as ink containers that are needed cleaning to change color. In each container, cleaning time exists to assign corresponding inks, and it is considered as the setup cost required to reduce the increasing productivity. The existing manual method, which is based on the worker's experience or intuition, is difficult to respond to the diversification of color requirements, mathematical modeling and algorithms are suggested for efficient scheduling. In this study, we propose a new type of scheduling problem for the printing process. First, we suggest a mathematical model that optimizes the color assignment and scheduling. Although the suggested model guarantees global optimality, it needs a lot of computational time to solve. Thus, we decompose the original problem into sequencing orders and allocating ink problems. An approximate function is used to compute the job scheduling, and local search heuristic based on 2-opt algorithm is suggested for reducing computational time. In order to verify the effectiveness of our method, we compared the algorithms' performance. The results show that the suggested decomposition structure can find acceptable solutions within a reasonable time. Also, we present schematized results for field application.

• Journal of Convergence for Information Technology
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• v.12 no.1
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• pp.1-6
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• 2022

As augmented reality technology becomes more common and prevelant, marker-based AR contents are applied in various ways. However AR contents are still hardly utilized due to the low recognition rate of marker images. In order to increase the recognition rate of AR marker images, this paper experiment and analyzed how much the recognition rate of markers could be improved when image correction and design changes was applied. The experimental result shows that the image correction task could significantly improve the number of image characteristics and the recognition grade if the image was modified in a way its saturation value is increased. Moreover, the recognition rate was improved even more when regular pattern design was added to the original marker image. In conclusion, it was possible to make the marker well recognized through proper correction of the image and additional process of pattern design in the process of producing the marker image.