• Journal of Internet Computing and Services
• /
• v.9 no.6
• /
• pp.179-188
• /
• 2008

Even though a lot of researches to improve the performance of TCP over wireless networks have been performed, the performance of TCP cannot satisfy users under high packet loss rate of wireless networks. This paper addresses the problem of TCP Westwood under high packet loss rate and reveals the reasons through the extensive simulation analysis. The ABE(Available Bandwidth Estimation) of TCP westwood becomes incorrect due to TCP dynamics of loss recovery. Based on this observation, we propose two algorithms for enhancing the correctness of ABE. We have evaluated the effects of the proposed algorithms through simulation. The proposed algorithms have achieved more correct ABE under the packet loss rate less than 1%.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.15 no.1
• /
• pp.323-342
• /
• 2021

Personal health records (PHRs) is an electronic medical system that enables patients to acquire, manage and share their health data. Nevertheless, data confidentiality and user privacy in PHRs have not been handled completely. As a fine-grained access control over health data, ciphertext-policy attribute-based encryption (CP-ABE) has an ability to guarantee data confidentiality. However, existing CP-ABE solutions for PHRs are facing some new challenges in access control, such as policy privacy disclosure and dynamic policy update. In terms of addressing these problems, we propose a privacy protection and dynamic share system (PPADS) based on CP-ABE for PHRs, which supports full policy hiding and flexible access control. In the system, attribute information of access policy is fully hidden by attribute bloom filter. Moreover, data user produces a transforming key for the PHRs Cloud to change access policy dynamically. Furthermore, relied on security analysis, PPADS is selectively secure under standard model. Finally, the performance comparisons and simulation results demonstrate that PPADS is suitable for PHRs.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.17 no.6
• /
• pp.1600-1619
• /
• 2023

Organizations and other institutions have recently started using cloud service providers to store and share information in light of the Internet of Things (IoT). The major issues with this storage are preventing unauthorized access and data theft from outside parties. The Block chain based Security Sharing scheme with Data Access Control (BSSDAC) was implemented to improve access control and secure data transaction operations. The goal of this research is to strengthen Data Access Control (DAC) and security in IoT applications. To improve the security of personal data, cypher text-Policy Attribute-Based Encryption (CP-ABE) can be developed. The Aquila Optimization Algorithm (AOA) generates keys in the CP-ABE. DAC based on a block chain can be created to maintain the owner's security. The block chain based CP-ABE was developed to maintain secures data storage to sharing. With block chain technology, the data owner is enhancing data security and access management. Finally, a block chain-based solution can be used to secure data and restrict who has access to it. Performance of the suggested method is evaluated after it has been implemented in MATLAB. To compare the proposed method with current practices, Rivest-Shamir-Adleman (RSA) and Elliptic Curve Cryptography (ECC) are both used.

• Microbiology and Biotechnology Letters
• /
• v.45 no.3
• /
• pp.236-242
• /
• 2017

The conversion of marine biomass to renewable energy has been considered an alternative to fossil fuels. Butanol, in particular, can be used directly as a fuel. In this experiment, the brown alga Undaria pinnatifida was selected as a biomass for biobutanol production. Hyper thermal (HT) acid hydrolysis was used as an acid hydrolysis method to produce monosaccharides. The optimal pretreatment conditions for U. pinnatifida were determined as slurry with 10% (w/v) U. pinnatifida content and 270 mM $H_2SO_4$, and heating at $160^{\circ}C$ for 7.5 min. Enzymatic saccharification was carried out with Celluclast 1.5 L, Viscozyme L, and Ultraflo Max. The optimal saccharification condition was 12 U/ml Viscozyme L. Fermentations were carried out for the production of acetone, butanol, and ethanol by Clostridium acetobutylicum KCTC 1724, Clostridium beijerinckii KCTC 1785, and Clostridium tyrobutyricum KCTC 5387. The fermentations were carried out using a pH-control. The optimal ABE fermentation condition determined using C. acetobutylicum KCTC 1724 adapted to 160 g/l mannitol. An ABE concentration of 9.05 g/l (0.99 g/l acetone, 5.62 g/l butanol, 2.44 g/l ethanol) was obtained by the consumption of 24.14 g/l monosaccharide with $Y_{ABE}$ of 0.37 in pH 5.0.

• The Journal of Korean-Japanese National Studies
• /
• no.21
• /
• pp.1-43
• /
• 2011

This article introduces Abe Mituie's activities related to Korean and Japanese Buddhism and two newly discovered materials. He worked as a brain of Japanese cultural rule over Joseon Korea while holding various positions such as the president of KyeongSung Il Bo, the vice president of Kokmin Newspaper and the director of Central Joseon Association. Abe was responsible for Enkak Temple, the head temple of Japanese Rinzai section, and was one of the layman followers of Syak Soen who worked for the spread of modern Japanese Buddhism to Europe and America. He was a respectful Buddhist layman so as to teach Zen Buddhism for young Buddhist monks in Japan. After he started to assume charge in the Kyeong Sung Il Bo, he was also very active in movements in relation to Joseon Buddhism to the extent that he was found to be deeply involved in Joseon Buddhism sections. On the other hand, he concluded Joseon culture to be 'devastated.' He asserted that it was necessary to develop spiritual culture and revive Buddhism in order to resolve the devastation in the Joseon. In addition, he thought that Joseon Buddhism was ruined due to the misgovernment of the Joseon Dynasty, but had its own as great tradition as Japanese Buddhism. Therefore, in his opinion, there was a need to do research on Joseon Buddhism and find some way out of the contemporary difficulties. In order to save the situation, he made efforts to protect and revive Joseon Buddhism while paying continuous visits to Joseon Buddhist temples, supporting the publication of Buddhist canons and proposing to have a regular meeting of 'The Invitation of 30 Head Temples.' From his visit to Youngju Temple and his consistent relationship with Kang Daeryeon, it can be assumed that he was involved in reorganizing power structure in Joseon Buddhism and establishing various institutions. He emphasized the strict adherence of individuals and communities to rules in his lecture for students at Jung Ang Hak Rim. It was a way to revive Joseon Buddhism by creating a new social image of Joseon Buddhism. He continued to work for the restoration of Joseon Buddhism even after he retired from Kyeong Sung Il Bo and returned to Japan. He introduced the originality of Joseon Buddhism history to Japan and sent Japanese monks to Korea in order to do research and contribute to exchange between Korean and Japanese Buddhism. All things taken together, it is evident that Abe Mitzihe regarded Joseon as backward or stagnant from a perspective of evolutionist or orientalist, and was a Japanese elite to believe that it was just for Japan to control Korea. However, he was different from other Japanese elites in that he did not considered Joseon Buddhism merely as the object of propagation. He thought that Joseon Buddhism possessed its own great tradition and culture, but was ruined because of the misadministration of the Joseon Royal House. Therefore, in his opinion, Joseon Buddhism should be recovered by means of some supports, and its revival would lead to the restoration of Joseon culture as a whole, which would be realized by Japanese rule over Korea and Japanese elites' generous assistance.

• Asian-Australasian Journal of Animal Sciences
• /
• v.2 no.3
• /
• pp.487-488
• /
• 1989

• Proceedings of the Korean Society for Language and Information Conference
• /
• 1992.02a
• /
• pp.132-144
• /
• 1992

• Proceedings of the Korean Society for Language and Information Conference
• /
• 1983.02b
• /
• pp.47-70
• /
• 1983

• Proceedings of the Korea Society of Costume Conference
• /
• 2001.08a
• /
• pp.75-77
• /
• 2001

• Proceedings of the Korea Society of Costume Conference
• /
• 2001.08a
• /
• pp.78-79
• /
• 2001