First report of Perkinsus honshuensis in the variegated carpet shell clam Ruditapes variegatus in Korea

The recent discovery of Perkinsus honshuensis, a new Perkinsus species infecting Manila clams Ruditapes philippinarum (Sowerby, 1852), in Japan, suggested that, based on proximity, P. honshuensis could also be in Korean waters, where to date, P. olseni was believed to be the only Perkinsus species present. Perkinsus sp. infections consistently occurred among Ruditapes variegatus clams on a pebble beach on Jeju Island, off the south coast of Korea. The typical \u27signet ring\u27 morphology of the parasite was observed in the connective tissue of the digestive gland, and infection intensity was comparatively low (3.3 x 10(3) +/- 1.2 x 10(4) to 1.3 x 10(4) +/- 6.1 x 10(4) cells g(-1) gill weight). Further DNA analyses of internal transcribed spacer (ITS-1, 5.8S and ITS-2) and non-transcribed spacer (NTS) regions of the parasite showed 98.9-99.8 and 98.5-99.5% similarity to those of P. honshuensis from Japan, respectively. Phylogenetic analyses using ITS and NTS sequences indicated that Perkinsus sp. from Jeju formed a highly supported clade with P. honshuensis. This is the first report of P. honshuensis infections in clams in Korean waters and the first report of R. variegatus as a host for that parasite

Dynamic Resource Management in CDRT Systems through Adaptive NOMA

This paper introduces a novel adaptive transmission scheme to amplify the prowess of coordinated direct and relay transmission (CDRT) systems rooted in non-orthogonal multiple access principles. Leveraging the maximum ratio transmission scheme, we seamlessly meet the prerequisites of CDRT while harnessing the potential of dynamic power allocation and directional antennas to elevate the system's operational efficiency. Through meticulous derivations, we unveil closed-form expressions depicting the exact effective sum throughput. Our simulation results adeptly validate the theoretical analysis and vividly showcase the effectiveness of the proposed scheme.Comment: 11 pages, 7 figures, submitted to IEEE journal for revie

Public Transportation Service Evaluations Utilizing Seoul Transportation Card Data

AbstractThis study evaluated transit service performance in Seoul using data collected from the Automatic Fare Collection (AFC) system in Seoul. The distance-based fare system in Seoul allows a maximum of four transfers with no additional charges to encourage transit ridership. In order to analyze the transit transfers, this study developed quantitative indicators for public transportation evaluations differentiated from those of previous studies by the fact that it utilizes data mining techniques which incorporate massive amounts of data (over 10 million transits per day) derived from the smart card system. This study not only carried out an evaluation to improve public transportation quality but provided comparative analysis of the mobility handicapped and an evaluation of public transportation users’ regional equity. This evaluative analysis of Level of Services (LOS) for various items is expected to be adopted for analyzing LOS status and generating improvement priorities and to be utilized as an objective database for public transportation policy decisions