Location and routing optimization protocols supporting internet host mobility

PhD ThesisWith the popularity of portable computers and the proliferation of wireless networking interfaces, there is currently a great deal of interest in providing IP networking support for host mobility using the Internet as a foundation for wireless networking. Most proposed solutions depend on a default route through the mobile host's horne address, which makes for unnecessarily long routes. The major problem that this gives rise to is that of finding an efficient way of locating and routing that allows datagrams to be delivered efficiently to moving destinations whilst limiting costly Internet-wide location updates as much as possible. Two concepts - "local region" and "patron service" - are introduced based on the locality features of the host movement and packet traffic patterns. For each mobile host, the local region is a set of designated subnetworks within which a mobile host often moves, and the patrons are the hosts from which the majority of traffic for the mobile host originated. By making use of the hierarchical addressing and routing structure of Internet, the two concepts are used to confine the effects of a host moving, so location updates are sent only to a designated host moving area and to those hosts which are most likely to call again, thus providing nearly optimal routing for most communication. The proposed scheme was implemented as an IP extension using a network simulator and evaluated from a system performance point of view. The results show a significant reduction in the accumulated communication time along with improved datagram tunneling, as compared with its extra location overhead. In addition, a comparison with another scheme shows that our functionality is more effective both for location update and routing efficiency. The scheme offers improved network and host scalability by isolating local movement from the rest of the world, and provides a convenient point at which to perform administration functions

SECBlock-IIoT : A Secure Blockchain-enabled Edge Computing Framework for Industrial Internet of Things

This work was supported by a National Research Foundation of Korea (NRF) grant funded by Korean Government (MSIT) (No. 2021R1A2C2014333).Postprin

Blockchain-Based Transaction Validation Protocol for a Secure Distributed IoT Network

Funding Agency: 10.13039/501100010418-Institute for Information and Communications Technology Promotion (IITP), Ministry of Science and ICT (MSIT); 10.13039/501100003621-Korea Government;Peer reviewedPublisher PD

Asymmetrical D-channel photonic crystal fiber-based plasmonic sensor using the wavelength interrogation and lower birefringence peak method

Funding Information: This work was supported in part by Independent University, Bangladesh ( IUB ), and in part by Sejong university through its faculty research program ( 20192021 ). This paper was also supported by research funds of Jeonbuk National University in 2020.Peer reviewedPublisher PD

Three newly recorded plants of South Korea: Muhlenbergia ramosa (Hack. ex Matsum.) Makino, Dichanthelium acuminatum (Sw.) Gould & C.A. Clark and Rottboellia cochinchinensis (Lour.) Clayton

AbstractThree new Poaceae species are reported in South Korea. Muhlenbergia ramosa was found in Boryeong-si, Iksan-si, Jangsu-gun and Gwangju. Dichanthelium acuminatum and Rottboellia cochinchinensis were found in Jeonju-si, Jeollabuk-do and Seogwipo-si, Jeju-do which were thought to be alien species. Genus Dichanthelium and Rottboellia are newly reported in South Korea. Muhlenbergia ramosa was thought to be native to Korea

Observation of ambipolar field-effect behavior in donor-acceptor conjugated copolymers

Although donor (D)-acceptor (A) conjugated copolymers possess an electron deficient unit, most D-A copolymers exhibit only hole transport properties (p-type). While there are some D-A copolymers that show ambipolarity, n-type behaviour is highly dependent on the type of acceptor used. In this work, ambipolar field-effect behaviour was derived from general D-A conjugated copolymers, believed to be a typical p-type material, by introducing a functional passivation layer between gate dielectric and active layers using polypropylene-co-1-butene (PPcB). The PPcB layer effectively covered the hydroxyl groups and induced a reduction in the energetic disorder at the semiconductor-insulator interface. As a result, the FET devices fabricated using D-A conjugated copolymers, such as PCDTBT, PTBT and Si-PCPDTBT, showed clear ambipolar properties.close2

Numerical development of high performance quasi D-shape PCF-SPR biosensor : An external sensing approach employing gold

This research was supported by the Sejong University through its Research Faculty Program ( 20192021 ).Peer reviewe

The Antioxidant Activity and Their Major Antioxidant Compounds from Acanthopanax senticosus and A. koreanum

The antioxidant activity and chlorogenic acid and caffeic acid contents were investigated from different parts of Acanthopanax senticosus and A. koreanum. Antioxidant activity was assessed by various in vitro assays such as DPPH, ABTS, FRAP, reducing power assays and ORAC, and the chlorogenic acid and caffeic acid were validated by HPLC chromatography. Among the various extracts, the fruit extracts of A. senticosus and A. koreanum exhibited strongest antioxidant activities including ABTS, FRAP, reducing power and ORAC, however, strongest DPPH radical scavenging activity was observed from the leaf extract of A. senticosus. In addition, the antioxidant activities of various extracts were correlated with total phenolic and proanthocyanidin contents. The major phenolic contents from various parts of these plants observed that leaf extract of A. senticosus expressed higher levels of chlorogenic acid (14.86 mg/dry weigh g) and caffeic acid (3.09 mg/dry weigh g) than other parts. Therefore, these results suggest that the leaf of A. senticosus may be an excellent natural source for functional foods and pharmaceutical agents, and the validated method was useful for the quality control of A. senticosus