• The Bulletin of The Korean Astronomical Society
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• 제38권2호
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• pp.95.2-95.2
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• 2013

The Van Allen Probes were designed to study the Earth's radiation belts on various scales of space and time. The identical two spacecrafts going nearly eccentric orbits lap each other several times over the course of the mission and each probe carries five instrument suites to address the science objectives on the radiation belt. Since Van Allen Probes launched on August 30, 2012, the probes detecte several storm events up to now. To understand the particle acceleration and loss mechanism in the radiation belt, we first focus on the energetic electrons' dynamics detected by ECT (Energetic Particle, Composition, and Thermal Plasma Suite). ECT measures near-Earth space's radiation particles covering the full electron and ion spectra from ~ eV to 10's of MeV with sufficient energy resolution. In this paper, we present the preliminary results of the recent several storm events using electron data from ECT(MagEIS and REPT).

• Journal of the Korea Institute of Building Construction
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• 제8권6호
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• pp.161-166
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• 2008

This study is focused on the welding performance of automatic gas pressure welding machine adapted to korean construction site by external appearance investigation. As gas pressure welding is more economical and has good performances compared with other steel bar jointing methods, as arc welding and mechanical joint etc, in Japan, the gas pressure welding is one of the typical connection of steel reinforcement when connecting the D29 and thicker steel bars, But in Korea, gas pressure welding joint method is not widely used caused by the shortage of skilled workers. so to activate the gas pressure welding in Korea, the automatic gas pressure welding machine is developed. In this study, the welding performances of gas pressure welding joint samples using korean automatic gas pressure welding machine are measured by external appearance investigation - blown diameters, blown length, welding face disagreement, central axis eccentric ratio, bending, sag and crack. The results of welding performances on the gas pressure welding joint samples show that samples are satisfied with the standard value regulated in KS D 0244 and JIS Z 3120.

• The Korean Journal of Cytopathology
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• 제12권1호
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• pp.45-48
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• 2001

Acinic cell carcinoma(ACC) is the third common malignancy in major salivary gland. Fine needle aspiration cytology is a useful tool for the diagnosis of salivary gland lesions. However, some low grade malignancies, such as ACC and mucoepidermoid carcinoma show relatively high false negative rate, mainly due to deceptively benign cytomorphologic appearance. We experienced a papillary-cystic variant of ACC, having different cytopathologic features compared with those of classic ACC. Our case showed monolayered sheets and papillary clusters without any acinic structures or naked nuclei of the tumor cells. Foamy proteinaceous material was seen in the background. The tumor cells had a large amount of granular cytoplasm and eccentric nuclei. Many vacuolated or clear cells were also noted.

• The Korean Journal of Cytopathology
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• 제9권1호
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• pp.99-104
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• 1998

Anaplastic large cell lymphoma(ALCL) is an uncommon type of non-Hodgkin's lymphoma(NHL) populated with anaplastic, often bizarre cells that express CD30 (Ki-1) antigen. The unusual histologic and cytologic features may cause confusion with other neoplasms, such as poorly differentiated carcinoma, melanoma, Hodgkin's disease, or true histiocytic lymphoma. Although the cytologic features of ALCL have been well described, there are few reports about cytologic findings of the sarcomatold variant of ALCL. We experienced a case of fine needle aspiration(FNA) cytologic findings of ALCL which mimicks malignant fibrous histiocytoma. FNA cytology of chest wall mass in a 62-year-old female with a history of peripheral T-cell lymphoma(Lennert lymphoma) revealed a heterogeneous population of single cells and poorly cohesive cells with large, pleomorphic nuclei and spindle cells gathering around vascular structures within an inflammatory background. Additional features of the neoplastic cells were eccentric, multilobated nuclei with occasional 'wreath-like' configuration; abundant cytoplasm with vacuolization; and prominent nucleoli. The cytologic features suggested sarcoma, especially malignant fibrous histiocytoma. The diagnosis was made retrospectively with an aid of immunocytochemical staining.

• The Korean Journal of Cytopathology
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• 제9권1호
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• pp.111-115
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• 1998

Although the characteristic cytologic features of melanoma have been well described the diagnosis of metastatic melanoma by fine needle aspiration cytology (FNAC) may be difficult in the case of amelanotic melanoma and in the absence of awareness of clinical history. Furthermore, when the breast is the site of initial presentation, it could simulate a primary breast carcinoma leading to misdiagnosis. The recognition of metastatic malignant melanoma in FNAC material is essential to avoid an unnecessary mastectomy and to ensure appropriate chemotherapy. We experienced a case of metastatic melanoma of breast which presented as solitary breast mass in a 56-year-old woman. She had a history of surgical excision of right foot for melanoma one year ago. The cytologic smears were composed of noncohesive epithelioid cells with round or eccentric nuclei, bi-or multi-nucleation, prominent nucleoli, fine chromatin, and intranuclear inclusions. The cytoplasm of tumor cells had scanty melanin pigment but were diffusely positive for S-100 protein.

• The Korean Journal of Cytopathology
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• 제9권1호
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• pp.123-127
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• 1998

The aspiration cytologic finding of myositis ossificans is not well documented but similar to that seen in nodular fasciitis except less cellularity. Myositis ossificans is a reactive condition that is sometimes mistaken microscopically for extraosseous osteosarcoma. Cytologically, myositis ossificans may be distinguished from extraosseous osteosarcoma by the presence of uniform benign stromal cells composed of mature fibroblasts and osteoclastic giant cells. However, the differential diagnosis may be difficult in the early stage of this reactive and proliferative process. We recently experienced a case of myositis ossificans. The patient was a 67-year -old woman with painful swelling of the left index finger for one month. Simple x-ray finding showed a soft tissue mass with calcific center at middle phalanx of the left hand. Fine needle aspiration cytology revealed a few individual or clusters of spindle cells in dense eosinophilic stroma with osteoclastic giant cells. The spindle cells were uniform smooth-bordered, and oval nuclei with single small inconspicuous nucleoli, and elongated cytoplasm. The scattered individual cells had eccentric nuclei with one or two nucleoli and abundant, basophilic cytoplasm.

• ALGAE
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• 제26권2호
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• pp.167-180
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• 2011

The unicellular marine red alga Erythrolobus australicus sp. nov. (Porphyridiophyceae) was isolated into laboratory culture from mangroves in Queensland and New South Wales, Australia. The single multi-lobed red to rose-red plastid has more than one pyrenoid and lacks a peripheral thylakoid. Arrays of small electron dense globules occur along the thylakoids. The nucleus is peripheral with a central to eccentric nucleolus. Each Golgi body is associated with a mitochondrion. The spherical cells are positively phototactic with slow gliding movement. The psaA + psbA phylogeny clearly showed that E. australicus is a distinct species, which is closely related to E. coxiae. The chemotaxonomically relevant and most abundant low molecular weight carbohydrate in E. australicus is floridoside with concentrations between 209 and 231 ${\mu}mol g^{-1}$ dry weight. Traces of digeneaside were also detected. These various approaches help to understand the taxonomic diversity of unicellular red algae.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.840-846
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• 2007

This paper investigates the dynamic behavior of a HDD spindle system due to the imperfect roundness of a rotating shaft. The shaft of a spindle motor rotates with eccentricity by the unbalanced mass of the rotating part. The eccentricity generates the run-out of a spindle motor which results in the eccentric motion of a rotating part. Roundness of a shaft affects this motion which limits the memory capacity of a HDD. This research proposes a modified Reynolds equation for the coupled journal and thrust FDBs to include the variable film thickness due to the roundness. Finite element method is used to solve the Reynolds equation for the pressure distribution. Reaction forces and friction torque are obtained by integrating the pressure and shear stress, respectively. The dynamic behavior is determined by solving the equations of a motion of a HDD spindle system in six degrees of freedom with the Runge-Kutta method to characterize the motion of a rotating part. This research shows that the roundness of a rotating shaft causes the excitation frequency with integer multiple of a rotating frequency.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.178-188
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• 2007

In this paper, a half-scaled substructure test was performed to evaluate the buckling and structural safety of an existing transmission tower subjected to wind load. A loading scheme was devised to reproduce the dead and wind loads of a prototype transmission tower, which uses a triangular jig that is mounted on the reduced model to which the similarity law of a half length was applied. As a result of the preliminary numerical analysis carried out to evaluate the stability of a specimen for the design load, it was confirmed that the calculated axial forces of tower leg members were distributed to $80{\sim}90%$ of an admissible buckling load. When the substructured transmission tower was loaded by 270% of its maximum admissible buckling load, it was failed due to the local buckling that is occurred in joints with weak constraints for out-of-plane behavior of leg members. By inspection of load-displacement curves, displacements and strains of members, it is considered that this local buckling was due to additional eccentric force by unbalanced deformation because the time that is reached to yielding stress due to the bending moment is different at each point of a same section.

• Journal of the Korean Society for Precision Engineering
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• 제32권8호
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• pp.735-741
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• 2015

Piezoelectric materials are well-utilized for transforming mechanical vibrations into electrical energy that can be stored and used to power a diversity of devices. In this work, these materials have been studied to improve the efficiency of a piezoelectric system, whereby the shape and vibration mode of a piezoelectric module was changed. The basic shape of the piezoelectric module used in this work comprises a width of 10 mm, a length of 30 mm, and a thickness of 0.2 mm. The structural design of the piezoelectric module is optimized using a Taguchi method to increase the corresponding electrical-energy generation. The maximum terminal voltage was defined as a characteristic value to evaluate the optimal design parameters. Through this work, we propose an optimal structure with an eccentric and centric mass; furthermore, the voltage increase of approximately 26% was obtained by comparing a general plate-vibrating piezosystem with an optimal plate-vibrating piezosystem.