• Journal of Ocean Engineering and Technology
• /
• v.17 no.4
• /
• pp.1-7
• /
• 2003

A virtual reality technology for multipurpose numerical simulation is developed to reproduce and investigate a variety of ocean environmental problems in a 3D Numerical Wave Tank(NWT). The governing equations for solving incompressible fluid motion are Navier-Stokes equation and continuity equation. The Marker-Density function technique is adopted to implement the fully nonlinear freesurface kinematic condition. The marine environmental situations, i.e., waves, currents, etc., are reproduced by use of multi-segmented wavemakers on the basis of the so-called ″snake-principle″. In this paper, some numerical reproduction techniques for regular, and irregular waves, multi-directional waves, Bull's-eye wave. wave-current, and solitary wave are presented, and a model test in motion with large amplitude of roll angle is conducted in the developed 3D-NWT, using a overlaid grid system.

• ALGAE
• /
• v.28 no.3
• /
• pp.233-240
• /
• 2013

Despite specimens' large size and ease of collection in northeast Asian waters, the species diversity of the genus Grateloupia still needs more research in Korea. We investigated plastid rbcL sequences and carried out detailed morphological observation on flattened halymeniacean red alga collected in twelve locations around Korea and Japan. We describe Grateloupia jejuensis sp. nov. based on the distinct clade with high support in our rbcL tree. Grateloupia jejuensis is characterized by solitary or caespitose habit and flattened thalli with discoid holdfast, cartilaginous texture, and blunt or bifid axis. Grateloupia jejuensis was distantly related to G. elata and G. cornea, which have been morphologically confused with the former, and it formed a sister relationship with Prionitis filiformis from California, USA in the rbcL tree.

• The Korean Journal of Cytopathology
• /
• v.16 no.1
• /
• pp.36-40
• /
• 2005

The mucoepidermoid carcinoma is a rare tumor in the lung for less than 1% of all pulmonary neoplasm. It is mostly presented as a solitary pulmonary nodule at a large bronchial tree on bronchoscope. But more peripheral located tumor that not accessible to the bronchoscope are rarely reported on literature. The cytologic findings of these tumors are discribed as a mixture of squamous cells, mucous cells, and intermediate cells with overlapped cellular clusters. We experienced a case of peripheral mucoepidermoid carcinoma of lung diagnosed by fine needle aspiration cytology. The smear showed many cellular clusters on mucoid background. They consisted of many intermediate cells with occasional mucus-secreting cells, but malignant squamous cells were not present.

• Imaging Science in Dentistry
• /
• v.44 no.1
• /
• pp.75-79
• /
• 2014

Glandular odontogenic cysts (GOCs) are rare intrabony solitary or multiloculated cysts of odontogenic origin. The importance of GOCs lies in the fact that they exhibit a propensity for recurrence similar to keratocystic odontogenic tumors and that they may be confused microscopically with central mucoepidermoid carcinoma. Thus, the oral and maxillofacial radiologists play an important role in definitive diagnosis of GOC based on distinctive cases; though they are rare. In large part, this is due to the GOC's complex and frequently non-specific histopathology. This report describes a case of GOC occurrence in the posterior mandibular ramus region in a 17-year-old female, which is a rare combination of site, age, and gender for occurrence.

• Investigative Magnetic Resonance Imaging
• /
• v.23 no.4
• /
• pp.361-366
• /
• 2019

Desmoplastic small round cell tumor (DSRCT) is a rare and aggressive malignancy common in young male patient. Typical imaging features of DSRCT include multiple soft tissue masses in the peritoneal cavity, omentum, or mesentery without an organ of origin. This report presents a rare manifestation of DSRCT revealing a solitary large retroperitoneal mass with hepatic metastasis and malignant portal vein thrombosis in 70-year-old women together with the review of literature. The tumor showed a hemorrhagic and necrotic mass with peripheral portion of T2 hypo-intensity and delayed enhancement that indicated desmoplastic stroma with dense cellularity.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2002.10a
• /
• pp.174-180
• /
• 2002

A virtual reality technology for multipurpose numerical simulation is developed to reproduce and investigate a variety of ocean environmental problems in a 3D-Numerical Wave Tank. The governing equations for solving incompressible fluid motion are Navier-Stokes equation and continuity equation, and the Marker-Density function technique is adopted to implement the fully-nonlinear free-surface kinematic condition. The marine environmental situations, i.e. waves, currents, wind, etc., are reproduced by use of multi-segmented wavemaker on the basis of the so-called "snake-principle". In this paper, some numerical reproduction techniques for regular and irregular waves, multi-directional waves, Bull's-eye wave, wave-current, and solitary wave are presented, and a model test in motion with large amplitude of roll angle is conducted in the developed 3D-NWT, using a overlaid grid system.

• Animal Systematics, Evolution and Diversity
• /
• v.38 no.4
• /
• pp.263-266
• /
• 2022

The genus Ephedrus Haliday, 1833 is a large taxon of Aphidiinae, consisting of 48 valid species in the world. This genus is considered to be important as a biological control agency, which includes solitary koinobiont parasitoids on aphids. One of its interesting characteristics is both male and female have 11-segmented antennae. In previous study, this genus was subdivided into three subgenus, Breviephedrus, Ephedrus and Fovephedrus, based on molecular and morphological characters. In this study, one Ephedrus species is firstly recorded from South Korea. Since it has been collected from Geumsan-gun in 2005 and deposited as dried specimen at Naturalis Biodiversity Center in Netherland, we recently confirmed it. Description and illustrations of the E. lacertosus are provided.

• Ocean Systems Engineering
• /
• v.5 no.4
• /
• pp.261-277
• /
• 2015

Internal solitary waves occur due to density stratification and are nonlinear in nature. These waves have been observed in many parts of the world including the South China Sea, Andaman Sea and Sulu Sea. Their effect on floating systems has been an emerging field of interest and recent offshore developments in the South China Sea where several offshore oil and gas discoveries are located have confirmed adverse effects including large platform motions and riser system damage. A valid numerical model conforming to the physics of internal waves is implemented in this paper and the effect on a spar platform is studied. The physics of internal waves is modeled by the Korteweg-de Vries (KdV) equation, which has a general solution involving Jacobian elliptical functions. The effects of vertical density stratification are captured by solving the Taylor Goldstein equation. Fully coupled time domain analyses are conducted to estimate the effect of internal waves on a typical truss spar, which is configured to South China Sea development requirements and environmental conditions. The hull, moorings and risers are considered as an integrated system and the platform global motions are analyzed. The study could be useful for future guidance and development of offshore systems in the South China Sea and other areas where the internal wave phenomenon is prominent.

• The Korean Journal of Cytopathology
• /
• v.7 no.2
• /
• pp.207-212
• /
• 1996

Angiosarcoma of the bone is rare with an incidence of 0.13%. It may be solitary or multiple. Its cytologic findings by FNA have rarely been reported. We report a case of angiosarcoma of the rib in a 66 year-old man. FNA revealed single or clusters of round to oval shaped cells in a hemorrhagic and myxoid background. The large central nuclei had irregular nuclear membrane, chromatin clumping and prominent nucleoli. The cytoplasm was scanty with an eosinophilic distinct cytoplasmic border. Erythrophagocytosis by malignant cells was also found. Histopathologic examination confirmed the diagnosis of angiosarcoma revealing irregular and complex anastomosing vascular channels lined by malignant round tumor cells, protruding into the lumen. Immunohistochemical staining revealed diffuse strong positive reaction to factor VIII-related antigen and CD31.

• The Korean Journal of Cytopathology
• /
• v.9 no.2
• /
• pp.193-199
• /
• 1998

Sclerosing hemangioma is a rare, benign neoplasm of the lung, usually presented as a solitary pulmonary nodule in an otherwise asymptomatic middle-aged woman. Cytologically it shows papillary, sheet, and cyst-like arrangements representing three main histologic patterns of papillary, solid, and angiomatous ones, respectively. Herein, we report the fine needle aspiration cytology of 5 cases of sclerosing hemangioma of the lung. The most characteristic finding is cyst-like spaces Intimately related to the papillary or solid cell nests. The tumor cells are relatively monotonous round to oval, small to medium in size. They have small amount of eosinophilic cytoplasm. The nuclei are uniform, round and have small but conspicuous nucleoli. The tumor cells in one of the presenting cases are large with abundant cytoplasm and show moderate nuclear pleomorphism. The nuclear chromatin, however, is fine and even without exception, even in the case showing nuclear pleomorphism. Major differential diagnoses based on the cytologic findings are well-differentiated papillary adenocarcinoma, bronchioloalveolar carcinoma, and carcinoid tumor.