• 한국입자에어로졸학회지
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• 제12권1호
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• pp.21-26
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• 2016

In order to realize In-line and convenient measurement for solid-gas two phase flows, Light Transmission Fluctuation (LTF) based on the random variation of transmitted light intensity, light scattering theory and cross-correlation method was presented for online measurement of particle size, concentration and velocity. The statistical relationship among transmitted light intensity, particle size and particle number in measurement zone was described by Beer-Lambert Law. Accordingly, the particle size and concentration were determined from the fluctuation signal of transmitted light intensity. Simultaneously, the particle velocity was calculated by cross-correlation analysis of two neighboring light beams. By considering the influence of concentration variation in industrial applications, the improved algorithm based on spectral analysis of transmitted light intensity was proposed to improve measurement accuracy and stability. Therefore, the online measurement system based on LTF was developed and applied to measure pulverized coal in power station and raw material in cement plant. The particle size, concentration and velocity of powder were monitored in real-time. It can provide important references for optimal control, energy saving and emission reduction of energy-intensive industries.

• Nuclear Engineering and Technology
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• 제53권4호
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• pp.1189-1198
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• 2021

When performing remote tasks using robots in nuclear power plants, a 3D shape measurement system is advantageous in improving the efficiency of remote operations by easily identifying the current state of the target object for example, size, shape, and distance information. Nuclear power plants have high-radiation and underwater environments therefore the electronic parts that comprise 3D shape measurement systems are prone to degradation and thus cannot be used for a long period of time. Also, given the refraction caused by a medium change in the underwater environment, optical design constraints and calibration methods for them are required. The present study proposed a method for developing an underwater 3D shape measurement system with improved radiation tolerance, which is composed of commercial electric parts and a stereo camera while being capable of easily and readily correcting underwater refraction. In an effort to improve its radiation tolerance, the number of parts that are exposed to a radiation environment was minimized to include only necessary components, such as a line beam laser, a motor to rotate the line beam laser, and a stereo camera. Given that a signal processing circuit and control circuit of the camera is susceptible to radiation, an image sensor and lens of the camera were separated from its main body to improve radiation tolerance. The prototype developed in the present study was made of commercial electric parts, and thus it was possible to improve the overall radiation tolerance at a relatively low cost. Also, it was easy to manufacture because there are few constraints for optical design.

• IMMUNE NETWORK
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• 제4권4호
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• pp.237-243
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• 2004

Background: The normal functions of the cell cycle inhibitor p16INK4a are frequently inactivated in many human cancers. Over 80% of hepatocellular carcinoma (HCC) cases lack a functional p16/Rb pathway. p16/Rb pathway, as well as p53 pathway, is considered as one of key components of tumor suppression. Methods: To study the roles of p16INK4a in HCC, a stable cell line expressing exogenous p16 was generated from SNU-449 hepatocellular carcinoma cells lacking endogenous p16, and suppression subtractive hybridization (SSH) was performed in parallel with the control cells. Results: 1) SSH identifies fibronectin (FN1), crystallin ${\alpha}B$ (CRYAB), Rac1, WASP, RhoGEF, and CCT3 as differentially-expressed genes. 2) Among the selected genes, the up-regulation of FN1 and CRYAB was confirmed by Northern blot, RT-PCR and by proteomic methods. Conclusion: These genes are likely to be associated with the induction of stress fiber and stabilization of cytoskeleton. Further studies are required to clarify the possible role of p16 in the signal transduction pathway.

• BMB Reports
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• 제28권4호
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• pp.316-322
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• 1995

The GTPase activating protein (GAP) can function both as a negative regulator and an effector of $p21^{ras}$. Overexpression of GAP in NIH-3T3 cells has been shown to inhibit transformation by ms or src. To investigate the function of GAP in a differentiative system, we overexpressed this protein in the nerve growth factor (NGF)-responsive PC12 cell line. Two-fold overexpression of GAP caused a delay of several days in the onset of NGF- but not FGF-induced neuronal differentiation of PC12 cells. However, the NGF-induced activation or tyrosine phosphorylation of upstream (Trk, PLC-${\gamma}1$, SHC) and downstream (B-Raf and $p44^{mapk/erk1}$) components of $p21^{ras}$, signalling cascade was not altered by GAP overexpression. Therefore, the change of phenotype induced by GAP was probably not due to GAP functioning as a negative regulator of $p21^{ras}$. Rather, we found that NGF-induced tyrosine phosphorylation of SNT, a specific target of neurotrophin-induced tyrosine kinase activity, was inhibited by GAP overexpression. SNT is thought to function upstream or independent of $p21^{ras}$. Thus in PC12 cells, overexpressed GAP may control the rate of neuronal differentiation through a pathway involving SNT rather than the $p21^{ras}$ signalling pathway.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.1146-1151
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• 2004

Measurements of OH chemiluminescence in an atmospheric pressure, laboratory-scale dump combustor at equivalence ratios ranging from 0.63 to 0.89 were reported. The signal from the first electronically excited state of OH to ground state was detected through a band-pass filter with an ICCD. The objectives of this study are two: One is to see the effects of equivalence ratio on global heat release rate and local Rayleigh index distribution. To get the local Rayleigh index distribution, the line-of-sight images were inverted by tomographic method, such as Abel de-convolution. Another aim is to investigate the validity of using OH chemiluminescence acquired with an ICCD as a qualitative measure of local heat release. For constant inlet velocity and temperature, the overall intensities of OH emission acquired at different equivalence ratio showed periodic and higher value at high equivalence ratio. OH intensity averaged over one period of pressure increased exponentially with equivalence ratio. Local Rayleigh index distribution clearly showed the region of amplifying or damping the combustion instability as equivalence ratio increased. It could provide an information/insights on active control such as secondary fuel injection. Finally, local heat release rate derived from reconstructed OH images were presented for typical locations.

• JSTS:Journal of Semiconductor Technology and Science
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• 제10권4호
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• pp.282-291
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• 2010

This paper presents a full-CMOS transmitter and receiver for VDSL2 systems. The transmitter part consists of the low-pass filter, programmable gain amplifier (PGA) and 14-bit DAC. The receiver part consists of the low-pass filter, variable gain amplifier (VGA), and 13-bit ADC. The low pass filter and PGA are designed to support the variable data rate. The RC bank sharing architecture for the low pass filter has reduced the chip size significantly. And, the 80 Msps, high resolution DAC and ADC are integrated to guarantee the SNR. Also, the transmitter and receiver are designed to have a wide dynamic range and gain control range because the signal from the VDSL2 line is variable depending on the distance. The chip is implemented in 0.25 ${\mu}m$ CMOS technology and the die area is 5 mm $\times$ 5 mm. The spurious free dynamic range (SFDR) and SNR of the transmitter and receiver are 67.5 dB and 41 dB, respectively. The power consumption of the transmitter and receiver are 160 mW and 250 mW from the supply voltage of 2.5 V, respectively.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 The 8th Asian Symposium on Precision Forging ASPF
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• pp.115-122
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• 2003

This paper presents the development of a virtual forging factory framework. The technologies of virtual reality and relational database had been integrated in the developed framework using Microsoft $Windows^{(R)}$ programming as the main technique so as to emulate a physical forging factory. The developed virtual forging factory consists of forging cells and a forging cell is comprised of forging machine, forging die, and forging operations forming a forging production line. The technology of virtual reality had been successfully adopted in the production simulation of manufacturing such as CNC and robotics. However, the application in virtual forging factory seems to have not been studied yet. Potential application of a virtual forging factory can be beneficial to (1) computer aided instruction, (2) shorten the learning curve of a novice, (3) remote diagnosis and monitoring when remote monitoring and control technology and signal inspection is considered, (4) improve adverse forging environment when remote forging technology is applied, and (5) virtual reality application.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권1호
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• pp.9-15
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• 2005

The objective of this study is screening the shear stress related proteins in chondrocytes using twodimensional electrophresis and MALDI-TOF. C-28/I2 cell line were grown. The fluid-induced shear stress(FISS) was applied using a cone viscometer at a rotational velocity of 80rpm for periods of 12 hours. Control cultures were tested under identical conditions without mechanical load application. Collected samples were used for the two-dimensional electrophoresis and MALDI-TOF. The identified proteins were calcyclin, RPE-spondin, interleukin-2, extracellular signal regulated kinase (ERK), lamin B2, porA protein, and RET-ELE1 protein. All of them showed a decreased expression. In conclusion, seven proteins were identified as a shear stress related proteins in chondrocytes. As the destruction of articular cartilage is one of main pathogenesis of TMJ internal derangement, this study will give useful information for the understanding of the molecular aspect of TMJ disease.

• 전기전자학회논문지
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• 제2권2호
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• pp.194-199
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• 1998

대기 무선 광통신시스템은 레이저 광의 높은 지향 특성에 의해 저전력 통신이 가능하나, 대기공간을 전송채널로 사용하기 때문에 전송되는 광신호는 흡수, 산란, 교란 등의 대기효과에 의해 심각한 영향을 받는다. 따라서, 본 논문에서는 이러한 대기효과를 고려하여 대기 광무선 LOS (line of sight) 통신링크의 링크방정식을 구한 후, 컴퓨터 시뮬레이션을 통해 무중계 전송거리를 구함으로써 시스템 성능을 평가하였다. 그 결과 주어진 데이터 전송율에서 무중계 전송 가능한 거리가 제시되었고, 주어진 비트 오류율에서 전송거리가 약간 증가함에 따라 데이터 전송율이 급격히 감소함을 알 수 있었다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권9호
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• pp.3779-3783
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• 2015

Dietary prevention has been known to reduce breast cancer risk. Sesamin is one of the major components in sesame seeds and has been widely studied and proven to have anti-proliferation and anti-angiogenic effects on cancer cells. In this study, the influence of sesamin was tested in the human breast cancer MCF-7 cell line for cell viability (MTT assay) and cell cycling (flow cytometry). Results showed that sesamin dose-dependently (1, 10 and $50{\mu}M$) reduced the cell viability and increased LDH release and apoptosis (TUNEL assay). In addition, there was a significant increase of sub-G1 phase arrest in the cell cycle after sesamin treatment. Furthermore, sesamin increased the expression of apoptotic markers of Bax, caspase-3, and cell cycle control proteins, p53 and checkpoint kinase 2. Taken together, these results suggested that sesamin might be used as a dietary supplement f or prevention of breast cancer by modulating apoptotic signal pathways and inhibiting tumor cell growth.