• Animal Systematics, Evolution and Diversity
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• v.34 no.4
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• pp.199-207
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• 2018

A chaetiliid isopod, Symmius caudatus Richardson, 1904 is newly recorded from Korea with detailed description and illustrations. This species is characterized by the following features: head has well-defined ocular lobes anteriorly projecting; all pereonites do not have any projections dorsally; maxillule has 2 long plumose and 1 short denticulate setae on inner lobe; propodus of pereopod 1 has 11 stout circumplumose setae on ventral margin in female; and pereopod 7 is ambulatory. In this paper, we present the descriptions and illustrations of mature and juvenile males, which have not been known from previous studies, as well as those of female. We also suggested a revised diagnosis of the genus Symmius.

• Animal Systematics, Evolution and Diversity
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• v.37 no.4
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• pp.322-329
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• 2021

A depressariid moth, Agonopterix issikii Clarke, 1962, feeing on Orixa japonica was newly recorded from Korea. Agonopterix issikii can be characterized by the brownish forewing mottled dark brown and black scales that show a dentate line at the base and three minute blackish dots in triangular at the median, and the basally pale gray hindwing. Agonopterix issikii is similar to A. ocellana Fabricius in external appearance but can be distinguished by the presence of brownish forewing with three blackish triangular dots at the median. The male genitalia of Agonopterix issikii can be characterized by the elliptic gnathos, the triangular socius, the rectangular valva with rather straight cuiller, and the stout phallus with a short basal process and the absence of cornutus. The female genitalia can be characterized by the funnel-shaped ostium bursae, the long ducuts bursae, and the ovate corpus bursae with a rounded patch of signa. To date, 12 species of the genus Agonopterix have been recorded in Korea.

• Animal Systematics, Evolution and Diversity
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• v.36 no.4
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• pp.296-303
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• 2020

Three species of the genus Dohrniphora, viz., D. cornuta, D. malaysiae, and D. prescherweberae were newly recorded from Korea. These newly recorded species can be easily identified by the characteristic that inner face of male hind femur equipped with a group of peg-like stout setae on basal sensory area. Peg-like setae are arranged perpendicularly in D. cornuta whereas linear in D. malaysiae and somewhat arched in D. prescherweberae. Also, concave area near the peg-like setae is also well developed in male which is smooth in D. cornuta, on the other hand, there is well developed distal carina in D. malaysiae and with groups of microtrichia in D. prescherweberae. In this study, detailed descriptions with photographs of three newly recorded species and a key to males of all Korean Dohrniphora species are provided.

• Animal Systematics, Evolution and Diversity
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• v.38 no.4
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• pp.248-259
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• 2022

Two newly recorded species of melitid amphipod, Abludomelita japonica (Nagata, 1965) and A. okhotensis Labay, 2016 belonging to the family Melitidae Bousfield, 1973 were collected from Korean waters. To date, only two genera, Dulichiella Stout, 1912 and Melita Leach, 1814, of the 28 genera of Melitidae have been recorded in Korea, so this is the first record of the genus Abludomelita from Korea. The genus Abludomelita Karaman, 1981 is morphologically similar to Melita Leach, 1814, however they are distinguished by having oblique row of setae on inner lobe of maxilla 2. Both newly recorded species are fully illustrated and compared with related species.

• Animal Systematics, Evolution and Diversity
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• v.39 no.3
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• pp.86-91
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• 2023

The genus Teloganopsis Ulmer belonging to the family Ephemerellidae is only known from the species of T. punctisetae (Matsumura, 1931) in the Korean Peninsula. The members of the genus Teloganopsis are characterized by the following characteristics: head and abdominal tergites without any tubercles and complex setae; forefemur with a row of long and stout setae perpendicularly; maxilla covered with dense setae. A total of 17 species had been previously recorded in this family. Here, Teloganopsis chinoi (Gose, 1980), is newly recorded in Korea which was found under a large stone in Kyeongho river. Larval habitus, habitat, line-drawings of key characters of the species, a checklist with habitus photos of Korean Ephemerellidae, and a key to the larvae of Korean Teloganopsis are provided.

• Parasites, Hosts and Diseases
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• v.22 no.1
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• pp.21-29
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• 1984

A scanning eletron microscopic study was performed to observe the tegumental surface of adult Fibricola seoulensis. The adult worms were collected from the small intestine of mice 5 days to 3 weeks after experimental infection with the metacercariae. The metacercariae were obtained from the viscera of the snakes, Matrix tigrina lateralis, by artificial digestion technique. The results were as follows: 1. The tegument of anterior body was covered with cobblestone-like cytoplasmic processes and that of posterior body showed finger-like processes. The posterior body had 4-5 large transverse wrinklings which formed many discontinued shallow rugae. 2. The entire surface of anterior body was regularly arranged with the spines of which tips diverged into 3 to 4 points. They were densely packed in anterior mid-median portion of dorsal surface where appeared a few spines indented upto 5 points. Farther laterally and posteriorly from this portion, the pointed spines were more sparse and became single tipped and extended to anterior one-third of posterior body, 3. The posterior surface of oral sucker was armed with 50-60 spines having 2-3 tips and ventral sucker also covered with such spines. On anteriormost dorsal surface arranged 60-70 spade-shaped spines. The tribocytic organ was armed with many stout recurved pile-like spines arranged radially. 4. There were 3 types of sensory papillae. The ciliated knob-like (Type I) papillae were almost bilaterally symmetrical in ventral and dorsal surfaces of anterior body, and abundant especially aroundbases of oral and ventral suckers, tribocytic organ, and in lateral margins of anterior body. About 24 non-ciliated round swellings (Type II) were observed around each lip of oral and ventral suckers. The plate-like elevated papilla without cilium (Type III) was found to distribute only in posterior body. These 3 types of papillae seem to be tangoreceptive and/or rheoreceptive in function when their morphology and distributions are considered.

• Journal of Mechanical Science and Technology
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• v.14 no.1
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• pp.72-83
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• 2000

In recent years considerable progress has been made in the characterisation of surface finish in three dimensions, and in the development of protocols which can be used for international standardisation. Although the subject as it has currently developed has much further to go if the process of surface characterisation is to impact on manufacture, control and specification of the manufacturing process itself. Researchers in this important area are beginning to realise that if the subject is to have great impact on manufacturing industries, surface characterisation must be broadened to include measures of surface integrity of the component and in addition be related to the functional demands imposed on the surface. The functional demands being a requirement of the engineering situation in which the components are employed. If these three factors are considered simultaneously, surface characterisation, surface integrity and component function, then a new and important subject is born, the subject of the Engineered Surface. Part 1 of this paper attempts to draw together the elements which go together to create the subject, 'The Engineered Surface'. The paper presents a method by which this important subject can be developed to the benefit of manufacturing industries. The paper also discusses the importance of a co-ordinated approach to the subject and the way that information can be documented to eventually provide a useful atlas of controlling parameters which are essential for a range of material processing industries as they strive to meet the ever more stringent and cost effective requirements of the manufacture.

• Structural Engineering and Mechanics
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• v.63 no.3
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• pp.269-280
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• 2017

One major concern that has occupied the mind of the designers is a structural failure as result of stress concentration in the geometrical discontinuities. Understanding the effective parameters contribute to stress concentration and proper selection of these parameters enables the designer get to a reliable design. In the analysis of perforated isotropic and orthotropic plates, the effective parameters on stress distribution around holes include load angle, curvature radius of the corner of the hole, hole orientation and fiber angle for orthotropic materials. This present paper tries to examine the possible effects of these parameters on stress analysis of infinite perforated plates with central quasi-square hole applying grey wolf optimizer (GWO) inspired by the particular leadership hierarchy and hunting behavior of grey wolves in nature, and also the present study tries to introduce general optimum parameters in order to achieve the minimum amount of stress concentration around this type of hole on isotropic and orthotropic plates. The advantages of grey wolf optimizer are stout, flexible, simple, and easy to be enforced. The used analytical solution is the expansion of Lekhnitskii's solution method. Lekhnitskii applied this method for the stress analysis of anisotropic plates containing circular and elliptical holes. Finite element numerical solution is employed to examine the results of present analytical solution. Results represent that by selecting the aforementioned parameters properly, fewer amounts of stress could be achieved around the hole leading to an increase in load-bearing capacity of the structure.

• Korean Journal of Environmental Biology
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• v.33 no.2
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• pp.160-169
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• 2015

Three unrecorded species of free-living marine nematodes, belonging to genus Enoplus Dujardin, 1845 collected from rocky intertidal seagrass on the eastern coast of Korea, are described and illustrated. Enoplus taipingensis Zhang and Zhou, 2012 is characterized by longer body size, a series of lateral setae throughout the tail in male, the presence of trumpet-shaped precloacal supplement with well-dilated proximal end, and the presence of spicules with five to eight semicircular plates. Enoplus meridionalis Steiner, 1921 is characterized by the presence of trumpetshaped precloacal supplement with slightly dilated proximal end, paired massive spicules, and tail with two pairs of stout terminal setae. Enoplus mammillatus Timm, 1959 is easily distinguished from the congeners by narrow tubular-shaped precloacal supplement. In this study, we provide detailed morphological features of three Enoplus species by differential interference contrast microscopy and scanning electron microscopy. This is the first report on the species of the genus Enoplus from the Korean waters.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.2
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• pp.231-240
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• 1988

An investigation is carried out for the load capacity characteristics of the externally pressurized air lubricated journal bearings both theoretically and experimentally. Theoretical analysis is made using the incremental method and the finite element method, and the discharge coefficient is considered. The experiments are performed for five bearings which are produced according to the rows of supply holes and the presence of poket or step. The results are compared with the numerical results. The present numerical results are in better agreement with the available experimental results than any other earlier numerical results for the bearings having one row and two rows of supply holes with pocket. The present numerical and experimental results show that the bearing with step has larger load capacity than that without step and that the load capacity increases as the clearance ratio increases.