• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.12 no.5
• /
• pp.157-162
• /
• 2013

To analyze the dynamic acceleration characteristics, it is necessary to identify the acceleration model using some methods that can represent the dynamic properties well. In this sense, fractal methods were used for the verification of characteristics of an acceleration signal. To estimate and analyze the geometry of acceleration signal, a fractal interpolation and its analysis was introduced in this paper. The chaotic nature of acceleration signal was considered in fractal modeling. In this study the fractal signal modeling has brought a focus within the scope of the fractal interpolation and fractal dimension. And a new idea of fractal dimension has been introduced and discussed considering the damping ratio and amplitude for its dynamic properties of the signal. The fractal dimension of acceleration with respect to the scaling factor using fixed data points of 1000 points was calculated and discussed. The acceleration behaviors of this results show some different characteristics. And this fractal analysis can be applied to other signal analysis of several machining such as pendulum type grinding and milling which has many dynamic properties in the signal.

• Biomolecules & Therapeutics
• /
• v.7 no.4
• /
• pp.329-334
• /
• 1999

Recently, cellular signal transduction mechanisms are greatly understood. However, bone cell signaling is not completely characterized. Interestingly, bone cells synthesize a number of growth factors such as IGF-I PDGF, IGF-II etc., suggesting these growth factors play important roles in bone cell signaling. In the present study, potential roles of nitric oxide (NO) and protein kinases in osteoblast signal transduction are proposed.

• BMB Reports
• /
• v.32 no.1
• /
• pp.28-32
• /
• 1999

Annexin I (also called lipocortin 1), a 37-kDa member of the annexin family of proteins, has been implicated in the mitogenic signal transduction by epidermal growth factor (EGF). Annexin I is phosphorylated by the EGF signal, however, the role of annexin I in the EGF signal transduction is still unknown. To transduce extracellular signals into the intracellular targets, selective translocation of the signaling molecules to their targets would be necessary. In this study, we examined the subcellular locations of annexin I during EGF signal transduction. Treatment of A549 cells with EGF resulted in the translocation of cytoplasmic annexin I to the nucleus and perinuclear region as determined by Western blot and immunofluorescent staining. The nuclear translocation of annexin I was inhibited by tyrphostin AG 1478 and genistein, the inhibitors of EGF receptor kinase and downstream tyrosine kineses, respectively. Pretreatment of cells with cyclohexamide did not inhibit the nuclear translocation. The results suggest that nuclear translocation of annexin I is controlled by a series of kinase dependent events in the EGF receptor signaling pathway and may be important in tranducing the signals by EGF.

• Journal of Microbiology
• /
• v.44 no.2
• /
• pp.217-225
• /
• 2006

Kaposi's sarcoma-associated herpesvirus (KSHV) RTA transcription factor is recruited to its responsive elements through interaction with RBP-Jk that is a downstream transcription factor of the Notch signaling pathway that is important in development and cell fate determination. This suggests that KSHV RTA mimics cellular Notch signal transduction to activate viral lytic gene expression. Here, I demonstrated that unlike other B lymphoma cells, KSHV -infected primary effusion lymphoma BCBL1 cells displayed the constitutive activation of ligand-mediated Notch signal transduction, evidenced by the Jagged ligand expression and the complete proteolytic process of Notch receptor I. In order to investigate the effect of Notch signal transduction on KSHV gene expression, human Notch intracellular (hNIC) domain that constitutively activates RBP-Jk transcription factor activity was expressed in BCBL1 cells, TRExBCBL1-hNIC, in a tetracycline inducible manner. Gene expression profiling showed that like RTA, hNIC robustly induced expression of a number of viral genes including KS immune modulatory gene resulting in downregulation of MHC I and CD54 surface expression. Finally, the genetic analysis of KSHV genome demonstrated that the hNIC-mediated expression of KS during viral latency consequently conferred the downregulation of MHC I and CD54 surface expression. These results indicate that cellular. Notch signal transduction provides a novel expression profiling of KSHV immune deregulatory gene that consequently confers the escape of host immune surveillance during viral latency.

• BMB Reports
• /
• v.38 no.1
• /
• pp.1-8
• /
• 2005

Transforming growth factor-$\beta$ is a pleiotropic growth factor that has enthralled many investigators for approximately two decades. In addition to many reports that have clarified the basic mechanism of transforming growth factor-$\beta$ signal transduction, numerous laboratories have published on the clinical implication/application of transforming growth factor-$\beta$. To name a few, dysregulation of transforming growth factor-$\beta$ signaling plays a role in carcinogenesis, autoimmunity, angiogenesis, and wound healing. In this report, we will review these clinical implications of transforming growth factor-$\beta$.

• Proceedings of KOSOMES biannual meeting
• /
• 2006.11a
• /
• pp.181-186
• /
• 2006

Geostationary Orbit satellite, unlike other sun-synchronous polar-orbit satellites, will be able to take a picture of a large region several times a day (almost with everyone hour interval). For geostationary satellite, the target region is fixed though the location of sun is changed always. However, Sun-synchronous polar-orbit satellites able to take a picture of target region same time a everyday. Thus Ocean signal is almost same. Accordingly, the ocean signal of a given target point is largely dependent on time. In other words, the ocean signal detected by geostationary satellite sensor must translate to the signal of target when both sun and satellite are located in nadir, using another correction model. This correction is performed with a standardization of signal throughout relative geometric relationship among satellite-sun-target points. This relative ratio called bidirectional factor. To find relationship between time and $[L_w]_N$/Bidirectional Factor differences, we are calculate solar position, geometry parameters. And reflectance, total radiance at the top of atmosphere(). And water leaving radiance, normalized water leaving radiance. And calculate bidirectional factor, that is the ratio of $[L_w]_N$ between target region and aiming the point. Then, we can make the bidirectional factor lookup table for one year imaging. So, we suggested for necessary to simulation experiment bidirectional factor in more various condition(wavelength and ocean/air condition).

• 한국초전도학회:학술대회논문집
• /
• 2007.07a
• /
• pp.56-56
• /
• 2007

• Proceedings of the KIEE Conference
• /
• 2006.10c
• /
• pp.416-418
• /
• 2006

In this paper, a new acoustic echo cancellation approach based on the DUET algorithm and scaling factor estimation is proposed to solve the scaling ambiguity in case of blind separation based acoustic echo cancellation in a noisy environment. In hands-free full-duplex communication system. acoustic noises picked up by the microphone are mixed with echo signal. For this reason, the echo cancellation system may provide poor performance. For that purpose, a degenerate unmixing estimation technique, adjusted in the time-frequency domain, is employed to separate undesired echo signals and noises. Also, since scaling and permutation ambiguities have not been solved in the blind source separation algorithm, kurtosis for the desired signal selection and a scaling factor estimation algorithm are utilized in this rarer for the separation of an echo signal. Simulation results demonstrate that the proposed approach yields better echo cancellation and noise reduction performances, compared with conventional methods.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.25 no.11
• /
• pp.113-122
• /
• 2011

This paper introduces and develops an efficient method for measuring power factor (PF) and its nature under nonlinear load current situations. The method is based on generating a pulse width modulated signal whose width correlates to the value of PF. This signal can then be employed as a feedback signal for controlling PF related power quantities in a system. This method has the advantages of its simple implementation, less computational complexity, and its allowable error of less than 4[%], which is justified by the computer simulation results.

• KSBB Journal
• /
• v.23 no.5
• /
• pp.460-462
• /
• 2008

Pollens grains collected from fully dehisced lily (Lilium longiflorum) anthers were given wounds by means of shaking in the presence of aluminum oxide particles. They were transformed by infiltration with Agrobacterium cells harboring a synthetic DNA encoding signal peptide-fused epidermal growth factor (EGF). After incubation for 24 hr in vitro, the pollen culture showed that EGF mRNAs and proteins were successfully expressed in the analysis of cDNA blot hybridization and immuno-blotting.