• Animal Systematics, Evolution and Diversity
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• 제33권4호
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• pp.267-273
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• 2017

The opossum shrimp, Siriella Dana, 1850 belongs to the family Mysidae Haworth, 1825. It is the genus of an enormous number of species with frequent morphological variations comprising 84 valid species to date. Among the species, Siriella trispina Ii, 1964 has been recorded from the Yellow Sea and the East China Sea is reported from Korean water for the first time. Siriella trispina is characterized by its exceedingly elongated 5th pair of thoracopods, the spines on the inner ventral margin of the uropodal endopod armed with secondary spinules, and 4-5 pairs of spines on the base of the telson. In the present study, we describe Korean specimens of the species in detail with photographs and illustrations. Siriella trispina is the 8th Siriella species found in Korean fauna.

• Animal Systematics, Evolution and Diversity
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• 제32권1호
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• pp.9-20
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• 2016

Two new species of poecilostomatoid copepods associated with echiurans are described from an intertidal mud flat in the Yellow Sea. A new genus Echiuricopus is created to accommodate two new species, E. aprilis and E. tenuipes. Major differences between the two new species are displayed in body length, length of caudal ramus seta I, length/width ratio of leg 5 exopod, and armature of the first antennular segment. Echiuricopus n. gen. is closely related to the genus Goidelia Embleton, 1901, but is distinguished from the latter chiefly by having seven caudal setae, a claw-like process on the first antennular segment, one claw-like process on the maxillary syncoxa, the absence of an inner coxal seta on legs 1-4, different armatures on legs 1-4, and an elongate leg 5 exopod.

• Animal Systematics, Evolution and Diversity
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• 제24권2호
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• pp.151-153
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• 2008

A female crab of Xenocarcinus conicus (A. Milne Edwards, 1865) was collected from Munseum, Jejudo Island. The genus Xenocarcinus is recorded newly in Korean brachyuran fauna. The present specimen has broader and shorter rostrum and eleven sharp teeth on the inner border of dactylus of the first ambulatory leg. Korean epialtid fauna now consists of eight species of four genera.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2000년도 춘계수산관련학회 공동학술대회발표요지집
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• pp.363-365
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• 2000

The cumacean fauna currently contains more than 1200 species worldwide (Wafting, 1997). Many of the habitats where cumaceans are likely to be found, such as estuaries, shallow embayments, beaches, tidal flats, and the inner continental shelf, have not yet had their cumacean fauna documented (Watling, 1997). (omitted)

• 한국해양공학회지
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• 제23권6호
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• pp.32-38
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• 2009

An FMEA for the waterjet-lifter of a DSNM is performed to prevent the occurrence of device failure. A waterjet-lifter raises and transports manganese nodules from the deep-sea floor up to a somewhat elevated place, from which a pin-scraper transports the lifted nodules to the inner space of the DSNM. A concept design for a device using the axiomatic design methodology is shown as the mapping between the functional domain and physical domain. The FMEA for a DSNM is introduced briefly and the rating criteria of severity, occurrence, and detection for the DSNM are defined. The FMEA of the functional requirements of a DSNM device is accomplished. Three kinds of failure modes, as well as their effects and causes, are predicted. Current design control methods for detecting potential failures, such as physical or computational experiments, design confirmation, and mathematical calculation, are described and the recommended actions for several significant causes are suggested.

• 한국수산과학회지
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• 제35권3호
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• pp.289-296
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• 2002

Using results obtained from field surveys in the outflow region of the Keum River in winter (February 22), spring (May 9), summer (July 31) and autumn (October 17) in 2000, it was described the nutrient front relating to the hydrography. It showed that the horizontal gradients was sharp in the distributions not only in salinity but also in nutrients in the region of the mouth of estuary far away about 20 km from the dyke of the Keum River during the year. The two layer structure was a ubiquitous feature in the inner estuarine side of the region showing the maximum horizontal gradients in salinity and nutrients. Although the absolute values in salinity and nutrient concentrations were distinguished by season, the nutrient front seperates the saltier and nutrients poor water in the open sea from the brackish and nutrients rich water of the plume. These results suggest that the nutrient front coincides with the esturine front in the region of freshwater influence (ROFI) of the Keum River.

• Journal of Advanced Marine Engineering and Technology
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• 제38권10호
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• pp.1333-1339
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• 2014

As the demand for petroleum resources increases, and oilfields on lands and in shallow-sea become exhausted, the areas for oil production are expanding to the deep sea and therefore technologies for flow assurance are coming into the highlight. In low temperature environment such as the deep sea, wax is accumulated and prevents stable oil production. Therefore, the development of flow assurance technologies is required. Wax is precipitated in crystalline form when the oil temperature decreases below the wax appearance temperature; it then accumulates on the inner walls of pipelines causing blockages. In particular, in subsea pipelines, which have a large surface contact area with the surrounding seawater, wax deposition problems are frequent. The internal tubular coating can effectively reduce wax deposition without pausing oil production when the coating is appropriately designed. This study carried out wax deposition tests on a number of internal tubular coatings under single flow conditions. The results were analyzed for the effects that the physical properties of the coatings had on wax deposition.

• 수산해양기술연구
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• 제53권4호
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• pp.317-326
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• 2017

Comparative fishing experiments were conducted in the eastern coastal waters near Uljin, Korea from 2002 to 2004, using the experimental trammel nets to estimate the selectivity for spinyhead sculpin Dasycottus setiger. The inner panels of the nets were made of nylon monofilament with four mesh sizes (82.2, 89.4, 104.8, and 120.2 mm) while its two outer panels were made of twisted nylon multifilament with a mesh size of 510 mm. The SELECT (Share Each Length's Catch Total) procedure with maximum likelihood method was applied to obtain a master selection curve. The different functional models (normal, lognormal, bi-normal, and logistic model) were fitted to the catch data. The lognormal model with the fixed relative fishing intensity was chosen as the best-fitted selection curve through comparison of model deviance and AIC (Akaike's Information Criterion). The optimum relative length (the ratio of fish total length to mesh size) with the maximum relative efficiency was obtained as 2.492.

• 한국표면공학회지
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• 제49권5호
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• pp.439-446
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• 2016

In 2015, a fin tube (Cu-Ni 70/30 alloy) of package type heat exchanger for navy vessel was perforated through the wall which led to refrigerant leakage. This failure occurred after only one year since its installation. In this study, cause of the failure was determined based on available documents, metallographic studies and computational fluid dynamics simulation conducted on this fin tube. The results showed that dimensional gap between inserted plastic tube and inside wall of fin tube is the cause of the swirling turbulent stream of sea water. As a result of combination of swirling turbulence and continuing collision of hard solid particles in sea water, erosion corrosion has begun at the end of inserted plastic tube area. Crevice corrosion followed later in the crevice between the outer wall of plastic tube and inner wall of fin tube. It was found that other remaining tubes also showed the same corrosion phenomena. Thorough inspection and prompt replacement will have to be accomplished for the fin tubes of the same model heat exchanger.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2007년도 특별 심포지엄 논문집
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• pp.73-83
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• 2007

We interpreted marine seismic profiles in conjunction with swath bathymetric and magnetic data to investigate rifting to breakup processes at the eastern Korean margin that led to the separation of the southwestern Japan Arc. Analysis of rift fault patterns suggests that rifting at the Korean margin was primarily controlled by normal faulting resulting from extension rather than strike-slip deformation. Two extension directions of E-W and NW-SE for rifting are recognized. We interpret that the E-W direction represents initial rifting at the inner margin and the NW-SE direction probably represents the extension in response to tensional tectonics associated with the subduction of the Pacific Plate in the NW direction. No significant volcanism was involved in rifting. In contrast, the inception of sea floor spreading documents a pronounced volcanic phase which appears to reflect asthenospheric upwelling as well as rift-induced convection particularly in the narrow southern margin. We suggest that structural and igneous evolution of the Korean margin, although it is in a back-arc setting, can be explained by the processes occurring at the passive continental margin with magmatism influenced by asthenospheric upwelling.