• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.6
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• pp.1243-1252
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• 2012

Due to the widespread use of smart devices, threats of direct observation attacks such as shoulder surfing and recording attacks, by which user secrets can be stolen at user interfaces, are increasing greatly. Although formal security models are necessary to evaluate the possibility of and security against those attacks, such a model does not exist. In this paper, based on the previous work in which a HCI cognitive model was firstly utilized for analyzing security, we propose STM-GOMS model as an improvement of GOMS-based model with regard to memory limitations. We then apply STM-GOMS model for analyzing usability and security of a password entry scheme commonly used in smart devices and show the scheme is vulnerable to the shoulder-surfing attack. We finally conduct user experiments to show the results that support the validity of STM-GOMS modeling and analysis.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.2
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• pp.61-70
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• 2011

Virtualization is a technology that uses a logical environment to overcome physical limitations in hardware. As a part of cost savings and green IT policies, there is a tendency in which recent businesses increase the adoption of such virtualization. In particular, regarding the virtualization in desktop, it is one of the most widely used technology at the present time. Because it is able to efficiently use various types of operating systems in a physical computer. A virtual machine image that is a key component of virtualization is difficult to investigate. because the structure of virtual machine image is different from hard disk image. Therefore, we need researches about appropriate investigation procedure and method based on technical understanding of a virtual machine. In this research, we suggest a procedure of investigation on a virtual machine image and a method for a corrupted image of the VMware Workstation that has the largest number of users.

• Journal of Digital Convergence
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• v.19 no.6
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• pp.233-238
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• 2021

Recently, blockchain technology accumulates and stores all transactions. Therefore, in order to verify the contents of all transactions, the data itself is compressed, but the scalability is limited. In addition, since a separate verification algorithm is used for each type of transaction, the verification burden increases as the size of the transaction increases. Existing blockchain cannot participate in the network because it does not become a block sink by using a server with a low specification. Due to this problem, as the time passes, the data size of the blockchain network becomes larger and it becomes impossible to participate in the network except for users with abundant resources. Therefore, in this paper, we are improved transaction as studied the zero knowledge proof algorithm for general operation verification. In this system, the design of zero-knowledge circuit generator capable of general operation verification and optimization of verifier and prover were also conducted.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.2
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• pp.149-157
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• 2020

Today, due to the large amount of data duplication caused by the increase in user data, various deduplication studies have been conducted. However, research on personal storage is relatively poor. Personal storage, unlike high-performance computers, needs to perform deduplication while reducing CPU and memory resource usage. In this paper, we propose an adaptive algorithm that selectively applies fixed size chunking (FSC) and whole file chunking (WFH) according to the file type and size in order to maintain the deduplication rate and reduce the load in personal storage. We propose an algorithm for minimization. The experimental results show that the proposed file system has more than 1.3 times slower at first write operation but less than 3 times reducing in memory usage compare to LessFS and it is 2.5 times faster at rewrite operation.

• Journal of Internet Computing and Services
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• v.23 no.5
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• pp.103-110
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• 2022

Botnets have been exploited for a variety of purposes, ranging from monetary demands to national threats, and are one of the most threatening types of attacks in the field of cybersecurity. Botnets emerged as a centralized structure in the early days and then evolved to a P2P structure. Bitcoin is the first online cryptocurrency based on blockchain technology announced by Satoshi Nakamoto in 2008 and is the most widely used cryptocurrency in the world. As the number of Bitcoin users increases, the size of Bitcoin network is also expanding. As a result, a botnet using the Bitcoin network as a C&C channel has emerged, and related research has been recently reported. In this study, we propose an encrypted botnet C&C communication mechanism and technique in the Bitcoin network and validate the proposed method by conducting performance evaluation through various experiments after building it on the Bitcoin testnet. By this research, we want to inform the possibility of botnet threats in the Bitcoin network to researchers.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.1
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• pp.29-35
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• 2023

In this paper, we propose a SW-EDU bot, a chatbot learning model for coding education by using a chatbot system. The same scenario-based models are created on the basis of Dialogflow and Kakao i Open Builder, which are representative chatbot builders. And then a SW-EDU bot is designed and implemented by selecting the builder more appropriate to our purpose. The implemented chatbot system aims to learn effective learning methods while encouraging self-direction of users by providing learning type selection, concept learning, and problem solving by difficulty level. In order to compare the usability of chatbot builders, five indicators are selected, and based on these, a builder with a comparative advantage is selected, and SW-EDU bot is implemented based on these. Through usability evaluation, we analyze the feasibility of SW-EDU bot as a learning support tool and confirm the possibility of using it as a new coding education learning tool.

• Journal of Industrial Convergence
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• v.20 no.5
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• pp.69-76
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• 2022

This paper summarizes the features and functions of game video on each platform through a study on streaming technology. Game videos have a high relationship with game content itself for the purpose of marketing and disseminating game play methods using games as the subject matter. The video length is short and it is easy to spread. The main types of game video content are game commentary, game strategy, funny, imitative, music video, and game information. As a game promotion video function, etc., it is used as a direct or indirect publicity for the game by the producer and the user for each reason. This article analyzed the production subject and production conditions of game videos, focusing on the production process. The production subject is divided into professional creators, non-professional creators, and general users. The motive for producing game videos is mainly to obtain economic benefits. The production process was extracted and presented through examples of game videos.

• Journal of the Korea Society of Computer and Information
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• v.27 no.11
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• pp.67-80
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• 2022

In this paper, we propose a system which automatically generates the ShEx schemas to describe and validate RDF knowledge graphs constructed by RML mapping. ShEx schemas consist of constraints. The proposed system generates most of the constraints by converting the RML mapping rules. The schemas consisting only of constraints obtained from mapping rules can help users to figure out the structure of the graphs generated by RML mapping, but they are not sufficient for sophisticated validation purposes. For users who need a schema for validation, the proposed system is also able to provide the schema with added constraints generated from metadata extracted from the input data sources for RML mapping. The proposed system has the ability to handle CSV, XML, JSON or RDBMS as input data sources. Testing results from 297 cases show that the proposed system can be applied for RDF graph validation in various practical cases.

• Journal of the Korea Society of Computer and Information
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• v.14 no.5
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• pp.167-174
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• 2009

The meaning of Database in order to manage the data which is huge in the meeting of the record which logically had become the fire tube or file 'efficiently' is widely used from the place which controls a many double meaning data. Like this data base it creates, it manages, the programs which send an answer back according to demand of the user as DBMS it calls. Like this it will be able to grasp the quality level of the data base software product which is important index from the research which index it buys it defined. Also, in order to produce the result of index it selects the collection item which is necessary and collection and analysis it leads and what kind of defect types occur substantially mainly, and it confirmed and the test and evaluation model in about data base software and a tentative instance it developed it analyzed.

• The Journal of Korean Institute of Next Generation Computing
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• v.13 no.5
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• pp.80-92
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• 2017

The popularity of cloud computing has led to the emergence of various types of cloud services, and the hybrid cloud, a deployment model that integrates public cloud and private cloud and offset their shortcomings, is in the spotlight recently. However, the complexity of different clouds integration and the lack of related integration solutions have delayed the adoption of hybrid cloud and cloud strategy by companies and organizations. Therefore, in this paper, we propose a cloud integration mechanism to solve the integration complexity problem. The cloud integration mechanism proposed in this paper consists of integration script that solves the cloud integration by the script based on the hybrid cloud function, a process of creating and executing it, and a script creation model applying the software design pattern. By integrating the various cloud services, we can quickly generate scripts that meet the user's needs. It is expected that the introduction of hybrid cloud and the acquisition of cloud strategy can be accelerated through this proposed integration mechanism.