• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.59.3-59
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• 2001

In this paper, the method of analyzing mobility of the mechanisms is suggested. The method based on the joint screws provides accurate values of mobility of the mechanisms even with the lack of geometric generality. To show its validity, the method is applied to finding mobilities of planar mobile robots and a rough-terrain mobile robot, Mars Rover. To do so, simplified joint model for each of four different typical wheels of the mobile robots are described including friction velocities, firstly. Then, mobility analyses of planar mobile robots and the Mars Rover mobile robot for navigation on the rocky road on Mars are performed. It is confirmed that the obtained results in this study coincide with the previous ones which ...

• Animal Systematics, Evolution and Diversity
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• v.37 no.4
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• pp.335-339
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• 2021

In 2020, during a survey of cnidarian fauna around Chuja-do locating in the northern part of Jeju-do, Korea, several hydroids were collected from the subtidal zone by SCUBA diving. Through taxonomic examination, one unrecorded species, Hydrodendron stechowi Hirohito, 1995, was found in Korea. It was newly added to the list of Korean hydrozoan fauna. This species was discovered for the first time since its first report as a new species in Japan. Their vivid orange-colored colonies were attached to the sponge on rocky substrate between depths of 15 and 20 m. Thus, a total of five species belonging to genus Hydrodendron, including the species reported in this study, have been reported in Korean waters so far.

• Geomechanics and Engineering
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• v.18 no.2
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• pp.111-119
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• 2019

Due to certain geological characteristics (high thickness, rocky properties), some underground coal mines require the use of explosives. This paper explores the effects of fragmentation of different decks detonated simultaneously in a single borehole with the use of numerical analysis. ANSYS/LS-DYNA code was used for the implementation of the models. The models include an erosion criterion to simulate the cracks generated by the explosion. As expected, the near-borehole area was damaged by compression stresses, while far zones and the free surface of the boundary were subjected to tensile damage. With the increase of the number of decks in the borehole, different changes in the fracture pattern were observed, and the superposition effects of the stress wave became evident, affecting the fragmentation results. The superposition effect is more evident in close distances to the borehole, and its effect attenuates when the distance to the borehole increase.

• Animal Systematics, Evolution and Diversity
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• v.36 no.4
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• pp.319-329
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• 2020

The sponge-dwelling shrimp, Anchistioides compressus Paulson, 1875, is recorded from Munseom Islet, Jejudo Island, Korea for the first time. All specimens were collected inside the orange coloured sponges by trimix diving at depth from 36-45 m on the rocky reef slope. Anchistioides compressus is characterized by the shape of the rostrum, the posterolateral teeth of the sixth somite, stylocerite being well developed, the anterior margin of the scaphocerite sharply produced, and the biunguiculate dactyli of the ambulatory pereiopods, as well as the proportions of the fingers of the second pereiopods. An illustrated description of the specimens and colour photo are provided to aid future recognition.

• Animal Systematics, Evolution and Diversity
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• v.38 no.4
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• pp.242-247
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• 2022

In 2021, during a survey of cnidarian fauna around Geomundo located in the Dadohaehaesang National Park in the South Sea, complete pinnated hydroid colonies attaching on vertical rocky surface at depth of 45 m were collected by SCUBA diving. Through taxonomic examination, unrecorded species, Sertularella acutidentata Billard, 1919, is newly added to the hydrozoan fauna of Korea. Recently, taxonomic position of the genus Sertularella has been relocated into the new family Sertularellidae Maronna et al., 2016 and six species from Korean waters have been synonymized or transferred to new genera. Thus, a total of 17 species belonging to genus Sertularella, including the species reported in this study, have been reported in Korean waters so far.

• Animal Systematics, Evolution and Diversity
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• v.22 no.1
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• pp.105-108
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• 2006

Some sea urchins were collected from the subtidal rocky bottom along the coastal line in Jeju Island by SCUBA diving in April 2005 and identified on the basis of their morphological characteristics. Among them, Asthenosoma ijimai Yochiwara, 1897 was newly recorded from Korea and redescribed based on the specimen collected at 20m deep in southern breakwater of Seogwipo harbor. The order Echinothurioida including family Echinothuriidae and genus Asthenosoma was firstly recorded in Korea. Seventeen species of echinoids are reported to be distributed in Jeju Island of Korea.

• Korean Journal of Plant Taxonomy
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• v.53 no.2
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• pp.166-169
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• 2023

Carex brevispicula (Cyperaceae) is endemic to Korea and is characterized by constricted achenes, short lateral spikes, and awned staminate and pistillate scales. The species classified in sect. Mitratae occurs throughout South Korea, perennating on mountains and/or rocky slopes under half shadow conditions. Meiotic chromosomes of the species were examined in this study, in which 33 meiotic cells from seven populations were found to be less than 2 ㎛ long with non-constricted chromosomes (n = 34_II). The stable chromosome number may be related to the narrow geographical distribution and/or distinct achene morphology. Further investigations of the distribution, morphological character variation, and chromosome characteristics should be conducted with closely related taxa to understand the derivation of the species and its endemism in Korea.

• Journal of Species Research
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• v.12 no.4
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• pp.368-373
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• 2023

The genus Acymatopus Takagi is reported for the first time from Korean fauna along with two nominate species, A. minor Takagi, 1965 and A. takeishii Masunaga, Saigusa & Yang, 2005. This genus belonging to the subfamily Hydrophorinae in the family Dolichopodidae. It comprised of only six species in the world and distributed only in Japan and China thus far. The genus is diagnosed by a metallic bluish-green body with thick gray tomentum, lacking black and white markings of mesonotum, 2 pairs of long marginal setae at scutellum and male's dorsally slightly curved fore tarsomere 1. Both adults and larvae of this genus are known to be found on rugged and rocky marine shores of the tidal zone. The authors found the first recorded species in the west seaside of Korea, where many barnacles inhabit. The descriptions and illustrations of external features including male genitalia of newly recorded species are provided in this paper.

• IMMUNE NETWORK
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• v.20 no.4
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• pp.30.1-30.10
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• 2020

Systemic infections due to Fusobacterium may originate in the tonsillar/internal jugular veins or from the abdomen. We encountered a patient who presented with bacteremia, fulminant septic shock, and extensive soft tissue pyogenic infection due to Fusobacterium necrophorum. In addition, there was widespread metastatic colon cancer with the unique finding of pre-mortem co-localization of F. necrophorum and cancer cells at a site distant from the colon. We reviewed the literature of the association of F. necrophorum and colon cancer, and discuss the evidence of how each of these 2 distinct entities may mutually augment the development or progression of the other.

• Economic and Environmental Geology
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• v.45 no.6
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• pp.685-695
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• 2012

We studied the detailed bathymetry and the geophysical characteristics of the summit of the Dokdo volcano using mutibeam echosounding and geophysical survey data. The bathymetry around the main east and west islets of the Dokdo volcano shows very shallow within about 10 m water depth. From near islets to about 30 m b.s.l., the shallow water area has very steep slope and many irregular sunken rocks. The area from about 30 m to about 80 m b.s.l. shows gentle rises and falls, and less steep slope. The area from 80 m b.s.l. has gradually flat undulation and smooth slope seabaed and is extended to offshore. The main islets of the Dokdo volcano and the rocky sea bottom elongated from the islets might be the residual part of the eroded and collapsed main crater of the Dokdo volcano. The bathymetry and the seafloor image(from backscattering) data show small craters, assumed to be formed by the eruption of later volcanism. The seafloor images propose that, except some areas with shallow sand sedimentary deposits, there are typical rocky bottom such as rocky protrusions and lack of sediments in the main morphology of the survey area. The stepped slopes of the seabed are deduced to be submarine terraces. The several prominent submarine terraces are found at the summit of the Dokdo volcano, suggesting repetition of sea level changes(transgressions and regressions) in the Quaternary. The results of the magnetic anomaly and the analytic signal have a good coherence with other geophysical consequences regarding to the location of the residual crater.