This paper aims to study the modeling and controller of an electrically driven tractor optimized for energy efficiency under off-road conditions and when subjected to loads such as plowing. The dynamic model design is aimed at a 30kW electric tractor. The vehicle model consists of a 30kW motor, transmission, wheels, and a controller, designed using the commercial software Matlab/Simulink. In order to optimize energy efficiency under load conditions, this paper designs and implements a PID controller focusing on the vehicle's speed and wheel slip. The newly proposed electric tractor modeling and PID controller aim to demonstrate improved energy efficiency through simulation.

Apolygus is one of speciose genus in subfamily Mirinae, including more than 80 species worldwide. Most of Apolygus species are phytophagous, and some species are regard as severe crop pest. For that, precise diagnosis and classification for this genus is crucial. In this work, we provide checklist of Korean Apolygus species with a new species and new distributional records. Diagnostic characters of the new species are discussed with the illustrations of adult male, female specimen and genitalic structures. A key to the Korean Apolygus is also presented.

The species of the genus Elasmostethus Fieber, 1860, belonging to the family Acanthosomatidae, occurring in the KoreanPeninsula are reviewed. Through this study, six species are recognized; the occurrence of four previously recorded species,including E. brevis Lindberg, 1934, E. humeralis Jakovlev, 1883, E. interstinctus (Linnaeus, 1758), and E. nubilus (Dallas,1851) are confirmed; two species, E. rotundus Yamamoto, 2003, and E. yunnanus Hsiao & Liu, 1977, are recorded forthe first time from the Korean Peninsula. The record of E. kansuensis Hsiao & Liu, 1977, is based on misidentificationof E. yunnanus. Therefore E. kansuensis is deleted from the Korean fauna. Photographs of habitus and genital segmentsof the two newly recorded species are included, and diagnoses and a key to the Korean species are provided.