• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.7
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• pp.1367-1372
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• 2007

This paper suggests One-time Password key exchange authentication technique for a strong authentication based on MANET and through identify wireless environment security vulnerabilities, analyzes current authentication techniques. The suggested authentication technique consists of 3 steps: Routing, Registration, and Running. The Routing step sets a safe route using AODV protocol. The Registration and Running step apply the One-time password S/key and the DH-EKE based on the password, for source node authentication. In setting the Session key for safe packet transmission and data encryption, the suggested authentication technique encrypts message as H(pwd) verifiers, performs key exchange and utilizes One time password for the password possession verification and the efficiency enhancement. EKE sets end to end session key using the DH-EKE in which it expounds the identifier to hash function with the modula exponent. A safe session key exchange is possible through encryption of the H(pwd) verifier. The suggested authentication technique requires exponentiation and is applicable in the wireless network environment because it transmits data at a time for key sharing, which proves it is a strong and reliable authentication technique based on the complete MANET.

• Nano
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• v.13 no.12
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• pp.1850140.1-1850140.9
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• 2018

An electrochemical sensor ($Cu^{2+}$-IIPs/GCE) was developed for detection of $Cu^{2+}$ in water. $Cu^{2+}$-IIPs/GCE was prepared by dispersing $Cu^{2+}$ imprinted polymers ($Cu^{2+}$-IIPs) on a preprocessed glassy carbon electrode. $Cu^{2+}$-IIPs were synthesized on the surface of modified carbon spheres by ion imprinting technology. The electrochemical performance of $Cu^{2+}$-IIPs/GCE was evaluated by differential pulse voltammetry method. The response of $Cu^{2+}$-IIPs/GCE to $Cu^{2+}$ was linear in $1.0{\times}10^{-5}mol/L$ to $1.0{\times}10^{-3}mol/L$. The detection limit was $5.99{\times}10^{-6}mol/L$ (S=N = 3). The current response value of $Cu^{2+}$-IIPs/GCE was 2.14 times that of the nonimprinted electrode. These results suggest that $Cu^{2+}$-IIPs/GCE can detect the concentration of $Cu^{2+}$ in water, providing a new way for heavy metal ions adsorption and testing.

• Journal of Microbiology and Biotechnology
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• v.32 no.3
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• pp.278-286
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• 2022

Live bacterial vector vaccines are one of the most promising vaccine types and have the advantages of low cost, flexibility, and good safety. Meanwhile, protein secretion systems have been reported as useful tools to facilitate the release of heterologous antigen proteins from bacterial vectors. The twin-arginine translocation (Tat) system is an important protein export system that transports fully folded proteins in a signal peptide-dependent manner. In this study, we constructed a live vector vaccine using an engineered commensal Escherichia coli strain in which amiA and amiC genes were deleted, resulting in a leaky outer membrane that allows the release of periplasmic proteins to the extracellular environment. The protective antigen proteins SLY, enolase, and Sbp against Streptococcus suis were targeted to the Tat pathway by fusing a Tat signal peptide. Our results showed that by exploiting the Tat pathway and the outer membrane-defective E. coli strain, the antigen proteins were successfully secreted. The strains secreting the antigen proteins were used to vaccinate mice. After S. suis challenge, the vaccinated group showed significantly higher survival and milder clinical symptoms compared with the vector group. Further analysis showed that the mice in the vaccinated group had lower burdens of bacteria load and slighter pathological changes. Our study reports a novel live bacterial vector vaccine that uses the Tat system and provides a new alternative for developing S. suis vaccine.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.8
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• pp.3187-3200
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• 2020

Finding key users in microblog has been a research hotspot in recent years. There are two kinds of key users: obvious and hidden ones. Influence of the former is direct while that of the latter is indirect. Most of existing methods evaluate user's direct influence, so key users they can find usually obvious ones, and their ability to identify hidden key users is very low as hidden ones exert influence in a very covert way. Consequently, the algorithm of finding hidden key users based on topic transfer entropy, called TTE, is proposed. TTE algorithm believes that hidden key users are those normal users possessing a high covert influence on obvious ones. Firstly, obvious key users are discovered based on microblog propagation scale. Then, based on microblogs' topic similarity and time correlation, the transfer entropy from ordinary users' blogs to obvious key users is calculated and used to measure the covert influence. Finally, hidden influence degrees of ordinary users are comprehensively evaluated by combining above indicators with the influence of both ordinary users and obvious ones. We conducted experiments on Sina Weibo, and the results showed that TTE algorithm had a good ability to identify hidden key users.

• Journal of applied mathematics & informatics
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• v.26 no.3_4
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• pp.563-572
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• 2008

In this paper, we discuss about a generalization of the Key Distribution Pattern which was proposed by C. Mitchell and F. Piper[6]. It is allowing secure communication between every n-pair of users($n\leq2$) in a large network for reducing storage requirements. We further suggest a generalization of K. Quinn's bounds in [9] for the number of subkeys in such general Key Distribution Patterns.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.539-539
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• 2005

• Animal Bioscience
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• v.37 no.7
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• pp.1141-1155
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• 2024

Objective: RNA epigenetic modifications play an important role in regulating immune response of mammals. Bovine mastitis induced by Staphylococcus aureus (S. aureus) is a threat to the health of dairy cattle. There are numerous RNA modifications, and how these modification-associated enzymes systematically coordinate their immunomodulatory effects during bovine mastitis is not well reported. Therefore, the role of common RNA modification-related genes (RMRGs) in bovine S. aureus mastitis was investigated in this study. Methods: In total, 80 RMRGs were selected for this study. Four public RNA-seq data sets about bovine S. aureus mastitis were collected and one additional RNA-seq data set was generated by this study. Firstly, quantitative trait locus (QTL) database, transcriptome-wide association studies (TWAS) database and differential expression analyses were employed to characterize the potential functions of selected enzyme genes in bovine S. aureus mastitis. Correlation analysis and weighted gene co-expression network analysis (WGCNA) were used to further investigate the relationships of RMRGs from different types at the mRNA expression level. Interference experiments targeting the m⁶ A demethylase FTO and utilizing public MeRIP-seq dataset from bovine Mac-T cells were used to investigate the potential interaction mechanisms among various RNA modifications. Results: Bovine QTL and TWAS database in cattle revealed associations between RMRGs and immune-related complex traits. S. aureus challenged and control groups were effectively distinguished by principal component analysis based on the expression of selected RMRGs. WGCNA and correlation analysis identified modules grouping different RMRGs, with highly correlated mRNA expression. The m⁶ A modification gene FTO showed significant effects on the expression of m⁶ A and other RMRGs (such as NSUN2, CPSF2, and METTLE), indicating complex co-expression relationships among different RNA modifications in the regulation of bovine S. aureus mastitis. Conclusion: RNA epigenetic modification genes play important immunoregulatory roles in bovine S. aureus mastitis, and there are extensive interactions of mRNA expression among different RMRGs. It is necessary to investigate the interactions between RNA modification genes regulating complex traits in the future.

• Parasites, Hosts and Diseases
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• v.52 no.2
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• pp.163-168
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• 2014

Wnt proteins are a family of secreted glycoproteins that are evolutionarily conserved and considered to be involved in extensive developmental processes in metazoan organisms. The characterization of wnt genes may improve understanding the parasite's development. In the present study, a wnt4 gene encoding 491amino acids was amplified from cDNA of metacestodes of Taenia solium using reverse transcription PCR (RT-PCR). Bioinformatics tools were used for sequence analysis. The conserved domain of the wnt gene family was predicted. The expression profile of Wnt4 was investigated using real-time PCR. Wnt4 expression was found to be dramatically increased in scolex evaginated cysticerci when compared to invaginated cysticerci. In situ hybridization showed that wnt4 gene was distributed in the posterior end of the worm along the primary body axis in evaginated cysticerci. These findings indicated that wnt4 may take part in the process of cysticerci evagination and play a role in scolex/bladder development of cysticerci of T. solium.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.9
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• pp.4529-4548
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• 2016

DDoS attacks have had a devastating effect on the Internet, which can cause millions of dollars of damage within hours or even minutes. In this paper we propose a practical dynamic defense approach that overcomes the shortage of static defense mechanisms. Our approach employs a group of SDN-based proxy switches to relay data flow between users and servers. By substituting backup proxy switches for attacked ones and reassigning suspect users onto the new proxy switches, innocent users are isolated and saved from malicious attackers through a sequence of remapping process. In order to improve the speed of attacker segregation, we have designed and implemented an efficient greedy algorithm which has been demonstrated to have little influence on legitimate traffic. Simulations, which were then performed with the open source controller Ryu, show that our approach is effective in alleviating DDoS attacks and quarantining the attackers by numerable remapping process. The simulations also demonstrate that our dynamic defense imposes little effect on legitimate users, and the overhead introduced by remapping procedure is acceptable.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.823-826
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• 2007

In ubiquitous environment, mobile devices, which users carry, tend to be resource-constraint, thus resulting in the need for an authentication protocol, which provides light-weight computations as well as strong security. Recently S/Key based protocols, which satisfy such a requirement by achieving light-weight computations, strong authentication and session key exchange, have been proposed. In particular, You and Jung's protocol is more efficient and secure than others. In this paper, we compare and analyze You-Jung with other protocols. Also, we design an authentication scenario and status of mobile devices while implementing the protocol.