• 한국구조물진단유지관리공학회 논문집
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• 제20권2호
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• pp.60-66
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• 2016

본 연구는 실리콘계 정포제의 특성에 따른 폴리우레탄 폼 지수제의 cell 구조와 흡수량 변화를 알아보기 위하여 6종의 정포제를 사용하여 폴리우레탄 폼 지수제를 제조하여 FE-SEM으로 분석한 결과 실리콘 정포제의 실록산 주사슬 말단에 PO n개가 결합되어 있는 DC-193, DC-2585, DC-5125, DC-198의 cell 구조는 close cell로 확인이 되었고, 실리콘 정포제의 실록산 주사슬 말단에 EO n개가 결합 되어 있는 DC-5043과 DC-5598은 open cell 구조로 나타났다. 또한 cell 구조 변화에 따른 흡수량 에서는 close cell의 크기가 가장 세밀하고 균일한 DC-193의 흡수량이 가장 적게 나타나 내수성이 가장 우수한 것으로 나타났으며 open cell의 크기가 가장 크게 형성된 DC-5043의 흡수량이 가장 많은 것으로 나타났다. 이들의 방수성능을 콘크리트 구조물을 모사하여 시험한 결과 누수가 없음을 확인하였다.

• 대한기계학회논문집A
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• 제31권3호
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• pp.380-387
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• 2007

We carried out an image analysis of living cells forming their contacts at the bottom of the cell culturing substrate. In order to visualize the contact area selectively, we adopted total-internal-reflection-fluorescence (TIRF) method, which can illuminate the specimen volume within only several hundred nano-meters above the substrate. From the fluorescent intensity of the TRF image, we could calculate the distance of the cell surface from the substrate. As a result, we visualized the origin of cell contacts, their movements, and the change of cell-contact type from the close-contact into focal-contact with information of its vertical displacement representing the temporal evolution process of the three-dimensional cell-surface-profile near the contact area during this metamorphosis.

• 한국세라믹학회지
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• 제33권3호
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• pp.293-298
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• 1996

Room temperature Li+ ion conductivities of Li3xLa(2/3-x)TiO3 system with x=0.117~0.317 were measured by complex impedance method. ICP, SEM and XRD analysis were conducted to study the main factor which influence the Li+ ion conductivity. Li+ ion conductivity seems to have a close relationship with the crystal structure of primitive cell increase as the primitive cell as close to cubic.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.562-564
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• 2002

Noise reduction and a simplification of a precision measurement system has been performed by changing analog output mode of a load cell into digital output mode. Usually, analog output signal of a few $\mu V$ from a load cell are amplified by amp and acquired by A/D converter. If the distance from a load cell to a DAS(Data Acquisition System) increases, more noise signals are mixed. So, a microprocessor has been integrated into a load cell so that the amplification and A/D conversion of output signals could be done in close proximity to the lode cell for the reduction in mixing of noise. Obtained data from the load cell like this manner are transferred to a computer with digital values(of TTL level). To simplify the configuration of a multi-channel DAS, RS-485 communication system has used for data transfer.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(2)
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• pp.40-43
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• 2000

The electrons and holes trapped in the tunneling oxide and interface-states generated in the Si/SiO$_2$ interface during program/erase (P/E) operations are known to cause reliability problems which can deteriorate the cell performance and cause the V$_{th}$ window close. This deterioration is caused by the accumulation of electrons and holes trapped in the oxide near the drain and source side after each P/E cycle. we propose three new erase schemes to improve the cell's endurance characteristics: (1)adding a Reverse soft program cycle after the source erase operation, (2)adding a detrapping cycle after the source erase operation, (3)adding a convergence cycle after the source erase operation. (3) is the most effective performance among the three erase schemes have been implemented and shown to significantly reduce the V$_{th}$ window close problem. And we are able to design the reliable periperal circuit of flash memory by using the (3).(3).

• E2M - 전기 전자와 첨단 소재
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• 제7권3호
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• pp.200-205
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• 1994

The FEM technique was applied to simulate the change of stress characteristics for various structural parameters and loading positions of the load cell. The output voltage of the load cell was then computed to compare with the manufactured load cell. The tendency of the stress variations of the load cell was well agreed with the basic formula of the single fixed. beam. Also, the stress characteristics according to the change of loading positions showed respective featured results as different structure. The calculated output voltages of the load cell were very close to those of the real manufactured ones.

• Bulletin of the Korean Chemical Society
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• 제34권12호
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• pp.3715-3721
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• 2013

In this study, the behavior of cells on the modified surface, and the correlation between the modified substrates and the response of cells is described. A close-packed layer of nano-sized silica beads was prepared on a coverslip, and the adhesion, proliferation, and migration of BALB/3T3 fibroblast cells on the silica layer was monitered. The 550 nm silica beads were synthesized by the hydrolysis and condensation reaction of tetraethylorthosilicate in basic solution. The amine groups were introduced onto the surfaces of silica particles by treatment with 3-aminopropyltrimethoxysilane. The close-packed layer of silica beads on the coverslip was obtained by the reaction of the amine-functionalized silica beads and the (3-triethoxysilyl)propylsuccinic anhydride treated coverslip. BALB/3T3 fibroblast cells were loaded on bare glass, APTMS coated glass, and silica bead coated glass with the same initial cell density, and the migration and proliferation of cells on the substrates was investigated. The cells were fixed and stained with antibodies in order to analyze the changes in the actin filaments and nuclei after culture on the different surfaces. The motility of cells on the silica bead coated glass was greater than that of the cells cultured on the control substrate. The growth rate of cells on the silica bead coated glass was slower than that of the control. Because the close-packed layer of silica beads gave an embossed surface, the adhesion of cells was very weak compared to the smooth surfaces. These results indicate that the adhesion of cells on the substrates is very important, and the actin filaments might play key roles in the migration and proliferation of cells. The nuclei of the cells were shrunk on the weakly adhered surfaces, and the S1 stage in which DNA is duplicated in the cell dividing processes might be retarded. As a result, the rate of proliferation of cells was decreased compared to the smooth surface of the control. In conclusion, the results described here are very important in the understanding of the interaction between implanted materials and biosystems.

• Applied Microscopy
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• 제17권2호
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• pp.31-40
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• 1987

The tentacular retractor muscle has many arrays of muscle fiber bundles under the epithelial layer. Most of muscle fiber bundles are arranged in parallel to the longitudinal axes of muscle fibers and a small number of them perpendiculary to them. These smooth muscle cells are filled with compactly arranged myosins and actins. These microfilaments, when the tentacle is protracted, keep abreast with straight for-ward-lined shapes while these microfilaments, when it is retracted, with curved shapes. The foldings in the sarcolemma of the muscle cell, when the tentacle is retracted, lead to the formation of normal subsurface tubules along with which a few mitochondria are included. It is thought that the formation of the sarcolemmal differentiation like the subsurface tubules has a close relation with the protraction and retraction of the tentacle. Mitochondria are found throughout the muscle cell, and sarcoplasmic reticulum (SR) developed greatly in the exoplasm close to the sarcolemma and associated with the cell membrane. Dense bodies are distributed irregularly and thin filaments are scattered around the thick filament in cross-sections, but the thin filaments may be arranged in complete or partial orbits around thick filaments. Complete orbits are infrequent.

• 한국시뮬레이션학회논문지
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• 제8권4호
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• pp.1-8
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• 1999

This paper proposes an ATM switch architecture called Output Queued Batcher-Banyan switch (OQBBS). It consists of a Sorting Module, Expanding Module, and Output Queueing Modules. The principles of channel grouping and output queueing are used to increase the maximum throughput of an ATM switch. One distinctive feature of the OQBBS is that multiple cells can be simultaneously delivered to their desired output. The switch architecture is shown to be modular and easily expandable. The performance of the OQBBS in terms of throughput, cell delays, and cell loss rate under uniform random traffic condition is evaluated by computer simulation. The throughput and the average cell delay are close to the ideal performance behavior of a fully connected output queued crossbar switch. It is also shown that the OQBBS meets the cell loss probability requirement of $10^{-6}$.

• Molecules and Cells
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• 제44권10호
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• pp.699-705
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• 2021

The centrosome is a subcellular organelle from which a cilium assembles. Since centrosomes function as spindle poles during mitosis, they have to be present as a pair in a cell. How the correct number of centrosomes is maintained in a cell has been a major issue in the fields of cell cycle and cancer biology. Centrioles, the core of centrosomes, assemble and segregate in close connection to the cell cycle. Abnormalities in centriole numbers are attributed to decoupling from cell cycle regulation. Interestingly, supernumerary centrioles are commonly observed in cancer cells. In this review, we discuss how supernumerary centrioles are generated in diverse cellular conditions. We also discuss how the cells cope with supernumerary centrioles during the cell cycle.