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A Review of the Phylogenetic Studies on the Kentish & Snowy Plovers
Woo-Yuel Kim,Dong-Yun Lee,Gun-hwa Kang,Ha-Cheol Sung National Institute of Ecology 2023 국립생태원회보(PNIE) Vol.4 No.2
The Kentish Plover (Charadrius alexandrinus ; family Charadriidae; genus Charadrius) is a small bird that moves from continent to continent depending on the season. On the Kentish Plovers, phylogenetic studies have been widely conducted to classify different species or subspecies and to determine the time of speciation. However, the perspectives on the interspecific or intraspecific relationships in the phylogenetic analysis of Kentish Plovers remain debatable. Here, we reviewed the differences between the Kentish and Snowy Plovers (C. nivosus ) in terms of their morphology, ecology, and genetic information. Particularly, their differences in genetic information can be well demonstrated; however, the intraspecies differences in the populations that live in different environments can relatively be poorly explained. We suggest that not only genetic features but also morphological, ecological, and behavioral traits are important when comparing the Kentish Plovers with other species, such as the Snowy Plovers, in phylogenetic studies. Furthermore, we suggest that phylogenetic studies on the subspecies of the Kentish and Snowy Plovers should be conducted for their better identification.
Ju Yuel Baek,Bo-Young Lee,Rita Pal,Mi Young Kim,Kwan Soo Kim 한국당과학회 2010 한국당과학회 학술대회 Vol.2010 No.1
Development of efficient and stereoselective glycosylation methodologies has been a major concern in synthetic organic chemistry over the past decade due to important roles of complex oligosaccharides in many fundamental life-sustaining processes. The selection of an appropriate glycosyl donor is one of the key processes for the successful glycosylation in terms of efficiency and stereoselectivity. We reported previously a new direct glycosylation method with anomeric hydroxy sugars as donors and phthalic anhydride and triflic anhydride as promoters, and the result of investigation of intermediates in the new glycosylation by low temperature NMR [1]. Although our direct glycosylation method works nicely in various glycosylations including stereoselective β-mannosylations, in certain cases, it gives undesired self-condensed esters of donors. In the first part of the lecture is presented a modified, improved method for the direct glycosylation with anomeric hydroxy sugars by employing phthalic anhydride derivatives in the place of phthalic anhydride itself. One of the most useful stereoselective glycosylation strategy utilizing protecting groups has been the 1,2-trans glycoside synthesis. Although the acyl groups at O-2 of donors give 1,2-trans glycosides by the neighboring group participation, their electron-withdrawing effects on the glycosylation stereochemistry might not have been properly recognized because of the overwhelming effect of the neighboring group participation. In fact, the effect of the non-participating electron-withdrawing groups such as methanesulfonyl and benzylsulfonyl groups at the O-2 positions of the donors on the glycosylation stereochemistry has been observed. Remote electron-withdrawing groups at O-3, O-4, and O-6 positions of pyranosyl donors or at O-3 and O-5 positions of furanosyl donors, which would reduce the reactivity of glycosyl donors, might also exert directing effects on the outcome of the stereochemistry of glycosylations. In fact, we reported previously that mannosylations of various acceptors with donors possessing an electron-withdrawing sulfonyl or acyl groups at O-3, O-4, or O-6 positions were found to be β-selective except when donors had 3-O-acyl and 6-O-acetyl groups, which afforded α-mannosides as major products [2]. The α-directing effect of 3-O-acyl and 6-O-acetyl groups was attributed to their remote participations while the origin of the β-directing effect was ascribed to the SN2-like reaction of the acceptor and the α-triflate intermediate, which is stabilized by remote electron-withdrawing groups. In the second part of the lecture is concerned with the directing effect of electron-withdrawing groups at the remote positions of donors on the stereochemistry in not only mannosylations but also other glycosylations. Directing effect of remote electron-withdrawing groups of other glycosyl donors was found to be quite different from the directing effect of those of mannosyl donors.
Cryptanalysis of Wu's Conference Key Distribution System
Jae-Yuel Im(임재열),Eun-Kyung Ryu(류은경),Eun-Jun Yoon(윤은준),Kee-Young Yoo(유기영) 한국정보과학회 영남지부 2005 한국정보과학회 영남지부 학술발표논문집 Vol.13 No.1
Recently, Wu presented a conference key distribution system that is intended to provide user anonymity. Wu’s scheme can be considered as a practical one in an application domain with less computing power. Since Wu’s scheme uses only one-way hash functions and simple algebraic operations, while most previous conference key distribution systems re-quire expensive modular exponentiations. However, Wu’s scheme has a limitation in that it is vulnerable to an impersonation attack by a malicious participant. In this paper, we show how the attack can be achieved in Wu’s scheme and also present an improvement to eliminate such a problem.
Behavior of Migrant Kentish Plovers (Charadrius alexandrinus) in the Ramsar Wetland of Yubu Island
Woo Yuel Kim,Eun Hong Lim,Doo-Pyo Lee,Ha-Cheol Sung 한국조류학회II 2015 한국조류학회지 Vol.22 No.2
The research in this study has been conducted on a daily basis from March 14 to April 2, 2013 in order to investigate, according to their habitats, the behaviors of Kentish Plovers (Charadrius alexandrinus), which breed and stop over in the Ramsar Wetland of Yubu Island in Janghang-eup, Seocheon-gun, Chungcheongnam-do. The sex of each individual bird was determined and the frequency of behaviors in the observed site was investigated. As a result, the size of the male population was about 2 times that of the female population and the number of the male population was also significantly dominant. The daily maximum number of individual birds were 174 on March 16th. The biggest difference between the male and female population sizes appeared on March 15th, having many male birds. The next day, March 16th, the largest number of female birds during the research period arrived. In terms of behaviors of male birds in salt farms and sand dunes, the stop behavior accounts for over 50 percent and feeding accounts for less 10 percent of their behaviors while, in mud flats, the stop behavior accounts for less 40 percent and feeding accounts for about 30 percent of their behaviors. The female birds also had a similar pattern of behaviors with male birds, but the frequency of their flight was significantly low compared to that of male birds. In terms of diurnal behaviors, birds fed in the morning and took a the stop behavior in the evening. After migration, the frequency of the stop behavior declined while the frequency of walking and feeding significantly increased. In this way, Kentish Plovers dominantly took the stop and feeding behaviors at the stopover site, Yubu Island, and this is believed to result from the fact that they replenish the energy sources that consumed during their migrations. Further continuous research will contribute to the providing fundamental data to protect and manage the birds and their habitats located in the major wetlands in South Korea.
김성률(Seong-Yuel Kim),이두천(Doo-Cheon Lee),김현애(Hyun-Ae Kim),임춘식(Choon-Sik Yim) 한국정보통신학회 2021 한국정보통신학회 종합학술대회 논문집 Vol.25 No.2
어구 자동식별 모니터링 시스템의 신뢰성 제고를 위해서는 실제 해상에서의 성능 시험이 중요하다. 본 연구를 통해 어구 자동식별 모니터링 시스템의 실해역 시험 개념과 RoLa와 LTE Cat.M1 통신 성능 시험 내용과 결과를 기술한다. The performance assessment in real sea is very important to increase the reliability of the fishing gear automatically identification monitoring system. The concept of real sea experiment for fishing gear automatically identification monitoring system is introduced and results of communication performance of RoLa and LTE Cat.M1 modules are reported through this research.
Energy Antenna for Efficient Dye-Sensitized Solar Cells.
Kwon, Dong Yuel,Chang, Dong Min,Kim, Young Sik American Scientific Publishers 2015 Journal of nanoscience and nanotechnology Vol.15 No.2
<P>In this study, we investigated the effect of the placement of acceptor in dual donor based dye sensitizers (TPA-PTZ-CN, PTZ-TPA-CN). Triphenylamine (TPA) and phenothiazine (PTZ) are well known as electron donors and cyanoacetic acid (CN) is a known electron acceptor. The absorption spectrum of the dyes showed different form because of the different energy levels of molecular orbital (MO) of each dye and intramolecular energy transfer (EnT). The absorption spectrum of PTZ-TPA-CN was broader than that of TPA-PTZ-CN and its molar extinction coefficient was also higher than TPA-PTZ-CN. Because of its enhanced panchromatic absorption spectra, PTZ-TPA-CN showed better photovoltaic properties than the other dyes did. This work presents that optimizing the placement of acceptor in dual donor based dye would give good photovoltaic properties for dye-sensitized solar cells (DSSC).</P>