• Smart Media Journal
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• v.9 no.1
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• pp.9-15
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• 2020

Recently there have been increasing attempts to apply blockchains to businesses and public institutions. Blockchain is a distributed shared ledger with excellent transparency and security of data and through consensus algorithm, the same data can be shared to all nodes in order. In this paper, Modified PBFT which does not modify the PBFT consensus algorithm is proposed. MPBFT is able to tolerate Byzantine faults on a private blockchain on an asynchronous network. Even with the increase of participating nodes, the network communication cost can be effectively maintained. Modified PBFT takes into account the characteristics of an asynchronous network environment where node-to-node trust is guaranteed. In response to the client's request, PBFT performed the entire participation broadcast several times, but Modified PBFT enabled consensus and authentication through the 2 / N leader. By applying the Modified PBFT consensus algorithm, the broadcast process can be simplified to maintain the minimum number of nodes for consensus and to efficiently manage network communication costs.

• Journal of the Korean Institute of Intelligent Systems
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• v.12 no.5
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• pp.411-416
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• 2002

Recently, the trial and success of malicious cyber attacks has been increased rapidly with spreading of Internet and the activation of a internet shopping mall and the supply of an online internet, so it is expected to make a problem more and more. Currently, the general security system based on Internet couldn't cope with the attack properly, if ever, other regular systems have depended on common softwares to cope with the attack. In this paper, we propose the positive selection mechanism and negative selection mechanism of T-cell, which is the biological distributed autonomous system, to develop the self/non-self recognition algorithm, the anomalous behavior detection algorithm, and AIS (Artificial Immune System) that is easy to be concrete on the artificial system. The proposed algorithm can cope with new intrusion as well as existing one to intrusion detection system in the network environment.

• Journal of the Korean Home Economics Association
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• v.12 no.2
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• pp.563-580
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• 1974

A Study of the Emotionality of Child and Mother The purpose of this study is primarily to understand the emotional climate of child and mother, which is a significant factor in child study and the home life. A sample was collected from a total of 1,592 of whom 796 are elementary school children with their mothers. Of these 796 children 440 are fom private schools, 190 from public schools in Seoul. The rest are taken from a farming area, 100 kilometers from Seoul. The data was basically obtained through answers to a questionaire distributed in September 1973. In this study, the cross-sectional method, percentage calculation and chi-square test are adapted from factor analysis. With this limited amount of data special attention now, the following conclusions can be drawn from this analysis although special attention should be given in making any kind of generalization about the entire population. 1) Children's emotionality (a) There is a higher percentage of emotionally well-adjusted children as opposed to maladjusted children.(51%>11%) (b) There is no correlation between children's emotionality and the following factors: grade, sex, residential area, school records, and educational level of their mothers. 2) Mother's Emotionality (a) There are more mothers who consider themselves happy than unhappy.(49%>2%) On the other hand a higher percentage of mothers reported feelings of tension and insecurity as compared to those who had feelings of firm security(65%>5%) (b) There is a high correlationshionship between marital adjustment and marital happiness. In other words, the more adjusted, the happier. A high marital happiness has strong influence on the preference of sex, on children's adjustment to their friends, and their present living condition. (c) There is a close relationship between a high marital adjustment and the social development of a child: being fond of fathers, homelife, and the acquaintance with many friends. In the same way, the positive emotionality of a mother in raising her children and their school records are also important. 3) Emotional relationship between a mother and her chid There is a close bond of love and respect between a mother and her child. Moreover, a high frequence of close and open-minded communication exist between them in a family. It is evident that the emotional climate of the mother has a strong and powerful influence on her child.

• Journal of Digital Convergence
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• v.12 no.10
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• pp.253-258
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• 2014

Recently, the development of cloud computing technology is developed as soon as smartphones is increases, and increased that users want to receive big data service. Hadoop framework of the big data service is provided to hadoop file system and hadoop mapreduce supported by data-intensive distributed applications. But, smpartphone service using hadoop system is a very vulnerable state to data authentication. In this paper, we propose a initial authentication protocol of hadoop system assisted by smartphone service. Proposed protocol is combine symmetric key cryptography techniques with ECC algorithm in order to support the secure multiple data processing systems. In particular, the proposed protocol to access the system by the user Hadoop when processing data, the initial authentication key and the symmetric key instead of the elliptic curve by using the public key-based security is improved.

• Journal of Digital Convergence
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• v.13 no.1
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• pp.263-268
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• 2015

Put your information in the object-based sensors and mobile networks has been developed that correlate with ubiquitous information technology as the development of IT technology. However, a security solution is to have the data stored in the server, what minimal conditions. In this paper, we propose a data management method is applied to a hash chain of the properties of the multiple techniques to the data used by the big user and the data services to ensure safe handling large amounts of data being provided in the big data services. Improves the safety of the data tied to the hash chain for the classification to classify the attributes of the data attribute information according to the type of data used for the big data services, functions and characteristics of the proposed method. Also, the distributed processing of big data by utilizing the access control information of the hash chain to connect the data attribute information to a geographically dispersed data easily accessible techniques are proposed.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.5
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• pp.99-106
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• 2011

In many applications, wireless sensor networks could be thought as data-centric networks, and the sensor nodes are densely distributed over a large sensor field. The sensor nodes are normally vulnerable in terms of security since they are very often deployed in a hostile environment and open space. In this paper, we propose a scheme for contents-based anomaly detection in wireless sensor networks. In this scheme we use the characteristics of sensor networks where several nodes surrounding an event point can simultaneously detect the phenomenon occurring and the contents detected from these sensors are limited to inside a certain range. The proposed scheme consists of several phases; training, testing and refining phases. Anomaly candidates detected by the distance-based anomaly detection scheme in the testing phase are sent to the refining phase. They are then compared in the sink node with previously collected data set to improve detection performance in the refining phase. Our simulation results suggest the effectiveness of the proposed scheme in this paper evidenced by the improvements of the detection rate and the false positive rate.

• The Journal of Korean Association of Computer Education
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• v.9 no.2
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• pp.111-124
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• 2006

Multicast services are provided on the Internet in fast increasing. Therefore it is important to keep security for multicast communication. If a member of the group is removed, new group key has to be generated and distributed to all remaining members of group. Minimizing number of messages and operation cost for generation of the composite keys to be used to encrypting group key are important evaluating criteria of multicast key management scheme since generation and distribution of new keys for rekeying require expensive operation. Periodic batch rekeying can reduce these important parameters rather than rekeying sequentially in fashion one after another. In this paper, Hamming distance is calculated between every members to be removed. In batch rekeying the members with Hamming distance less than threshold are selected for rekeying procedure. With running the round assignment algorithm in the case of removing several members simultaneously, our scheme has advantages of reducing messages and operation cost for generation of the composite keys and eliminating possibility of collusion attack for rekeying. We evaluate performance of round assignment algorithm through simulation and show that our scheme is excellent after performance comparison of existent schemes and our scheme.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.5
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• pp.593-600
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• 2018

Owing to the advancement of Internet and smart devices, access to various media such as social media became easy; thus, a large amount of big data is being produced. Particularly, the companies that provide various Internet services are analyzing the big data by using the MapReduce-based big data analysis techniques to investigate the customer preferences and patterns and strengthen the security. However, with MapReduce, when the big data is analyzed by defining the number of reducer objects generated in the reduce stage as one, the processing rate of big data analysis decreases. Therefore, in this paper, a MapReduce-based split big data analysis method is proposed to improve the log analysis processing rate. The proposed method separates the reducer partitioning stage and the analysis result combining stage and improves the big data processing rate by decreasing the bottleneck phenomenon by generating the number of reducer objects dynamically.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.2
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• pp.279-286
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• 2015

EMD is a fully data-driven signal processing method without using any predetermined basis function and requiring any user parameters setting. However EMD experiences a problem of mode mixing which interferes with decomposing the signal into similar oscillations within a mode. To overcome the problem, EEMD method was introduced. The algorithm performs the EMD method over an ensemble of the signal added independent identically distributed white noise of the same standard deviation. Even so EEMD created problems when the decomposition is complete. The ensemble of different signal with added noise may produce different number of modes and the reconstructed signal includes residual noise. This paper propose an modified EEMD method to overcome mode mixing of EMD, to provide an exact reconstruction of the original signal, and to separate modes with lower cost than EEMD's. The experimental results show that the proposed method provides a better separation of the modes with less number of sifting iterations, costs 20.87% for a complete decomposition of the signal and demonstrates superior performance in the signal reconstruction, compared with EEMD.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.5_6
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• pp.353-359
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• 2004

The illegal copying and redistribution of digitally-stored information is a crucial problem to distributors who electronically sell digital data. Fingerprinting scheme is a techniques which supports copyright protection to track redistributors of electronic information using cryptographic techniques. Anonymous fingerprinting schemes, differ from symmetric fingerprinting, prevent the merchant from framing a buyer by making the fingerprinted version known to the buyer only. And the scheme, differ from asymmetric fingerprinting, allows the buyer to purchase goods without revealing her identity to the merchant. In this paper, a new anonymous fingerprinting scheme based on secret sharing is introduced. The merchant finds a sold version that has been distributed, and then he is able to retrieve a buyer's identity and take her to court. And Schnorr's digital signature prevents the buyer from denying the fact he redistributed. The buyer's anonymity relies on the security of discrete logarithm and secure two-party computations.