• Bulletin of the Korean Chemical Society
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• v.33 no.9
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• pp.3071-3075
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• 2012

Human ${\alpha}$-synuclein is the major component of the protein aggregates known as Lewy bodies or Lewy neurites, which define the intracellular lesions of Parkinson's disease. Despite extensive efforts, the physiological function of ${\alpha}$-synuclein has not yet been elucidated in detail. As an approach to defining its function, proteins that interacted with ${\alpha}$-synuclein were screened in phage display assays. The SNARE protein vesicle t-SNARE-interacting protein homologous 1B (VTI1B) was identified as an interacting partner. A selective interaction between ${\alpha}$-synuclein and VTI1B was confirmed by coimmunoprecipitation and GST pull-down assays. VTI1B and ${\alpha}$-synuclein were colocalized in N2a neuronal cells, and overexpression of ${\alpha}$-synuclein changed the subcellular localization of VTI1B to be more dispersed throughout the cytosol. Considering the role played by VTI1B, ${\alpha}$-synuclein is likely to modulate vesicle trafficking by interacting with a SNARE complex.

• Geophysics and Geophysical Exploration
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• v.14 no.3
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• pp.191-202
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• 2011

Reserve-time migration (RTM) using a two-way wave equation is one of the most accurate migration techniques. RTM has been conducted by assuming that subsurface media are isotropic. However, anisotropic media are commonly encountered in reality. Conventional isotropic RTM may yield inaccurate results for anisotropic media. In this paper, we develop RTM algorithms for vertical transversely isotropic media (VTI) and tilted transversely isotropic media (TTI). For this, the pseudo-acoustic wave equations are used. The modeling algorithms are based on the high-order finite-difference method (FDM). The RTM algorithms are composed using the cross-correlation imaging condition or the imaging condition using virtual sources. By applying the developed RTM algorithms to the Hess VTI and BP TTI models, we could obtain better images than those obtained by the conventional isotropic RTM.

• Proceedings of the KSLP Conference
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• 1996.11a
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• pp.78-78
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• 1996

기식성 애성을 객관적으로 평가할 수 있는 음향지표는 아직 많은 연구가 되어 있지 않고 단지 청각심리검사에 의존하고 있는 실정이다. 본 저자들은 컴퓨터음향분석의 한 지표로서 기식성 애성에 대한 객관적인 음향지표로 이용될 수 있는 Multi-Dimensional Voice Program(mode1 4305, Kay Elemtrics Corp, USA)의 VTI(voice turbulance index)를 정상인과 성대병변 환자에서 비교 분석함으로써 기식성 애성의 객관적인 음향지표로서의 유용성을 확인하고자 하였다. (중략)

• Geophysics and Geophysical Exploration
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• v.16 no.2
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• pp.71-78
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• 2013

The one-way wave equation migration is much more computationally efficient comparing with reverse time migration and it can provide better image than the migration algorithm based on the ray theory. We have developed the prestack depth migration module adopting (GS) propagator designed for vertical transverse isotropic media. Since GS propagator considers the higher-order term by expanding the Taylor series of the vertical slowness in the thin slab of the phase-screen propagator, the GS migration can offer more correct image for the complex subsurface with large lateral velocity variation or steep dip. To verify the validity of the developed GS migration module, we analyzed the accuracy with the order of the GS propagator for VTI media (GSVTI propagator) and confirmed that the accuracy of the wavefield propagation with the wide angles increases as the order of the GS propagator increases. Using the synthetic seismic data, we compared the migration results obtained from the isotropic GS migration module with the anisotropic GS migration module. The results show that the anisotropic GS migration provides better images and the improvement is more evident on steeply dipping structures and in a strongly anisotropic medium.

• Geophysics and Geophysical Exploration
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• v.13 no.4
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• pp.307-314
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• 2010

Although conventional seismic data processing is based on the assumption that the media are isotropic, the subsurface is often anisotropy in shale formation or carbonate with cracks and fractures. This paper presents the anisotropic parameter and seismic modeling in transversely isotropic media with a vertical symmetry axis using seismic physical modeling. The experiment was successfully carried out with VTI media, laminated bakelite material, using contact transducer of p and s-wave transmission. The variation of velocities with angle of incidence was clearly shown in anisotropic material. Comparing these velocities with the calculated phase velocities, the (P) and (S)-wave velocity observed in anisotropic material was a very good agreement with the calculated values. Anisotropic parameter ${\varepsilon}$, ${\delta}$, ${\gamma}$ was estimated by using Lame's constant calculated from the observed velocity. For the purpose of testing (S)-wave polarization, a birefringence experiment was carried out. The higher velocity was associated with the polarization parallel to the fracture, and the lower velocity was associated with the polarization perpendicular to the fracture.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.9A
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• pp.1442-1450
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• 1999

In this paper, we present an efficient hardware architecture for the frame memory of the MPEG-2 video encoder. Both the total size of internal buffers and the number of logic gates are reduced by the proposed memory map which can provide an effective interface between MPEG-2 video encoder and the external DRAM. Furthermore, the proposed scheme can reduce the DRAM access time. To realize the frame memory hardware,$0.5\mu\textrm{m}$, VTI, vemn5a3 standard cell library is used. VHDL simulator and logic synthesis tool are used for hardware design and RTL (register transfer level) function verification. The frame memory hardware emulator of the proposed architecture is designed for gate-level function verification. It is expected that the proposed frame memory hardware using VHDL can achieve suitable performance for MPEG-2 MP@ML.

• Korean Journal of Veterinary Research
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• v.36 no.3
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• pp.607-614
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• 1996

Several methods for rapid and accurate detection of VTe-producing E coli were established. These methods contain beta-glucuronidase-secretion test, beta-haemolysis-production test in blood agar, verocytotoxicity test, and PCR. All of the VTe-producing strains made beta-haemolysis on 5% sheep blood agar. VTe-producing strains secreted beta-glucuronidase whereas 0157:H7 strains producing VTI or VTII did not secrete that enzyme. Verocytotoxicity test was established for rapid diagnosis. VTe detection was rapider in Vero cell suspension than Vero cell monolayer. In PCR, there was a positive result only in VTe-producing E coli, not in VTI or VTII-producing E coli. In this experiment, 165 strains of E coli were islated from feces or intestinal contents of post-weaning piglets showing nervous sign or diarrhea. And 20 strains of E coli that produced VTe were selected by verocytotoxicity test and PCR. According to these experiments, there was a direct correlation between verocytotoxicity test and PCR. And verocytotoxicity test is recommended as a routine diagnostic method and PCR does as a accurate diagnostic method to detect VTe-producing E coli.

• Geophysics and Geophysical Exploration
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• v.18 no.2
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• pp.74-84
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• 2015

To yield physically meaningful images through elastic reverse-time migration, the wavefield separation which extracts P- and S-waves from reconstructed vector wavefields by using elastic wave equation is prerequisite. For expanding the application of the elastic reverse-time migration to anisotropic media, not only the anisotropic modelling algorithm but also the anisotropic wavefield separation is essential. The anisotropic wavefield separation which uses pseudo-derivative filters determined according to vertical velocities and anisotropic parameters of elastic media differs from the Helmholtz decomposition which is conventionally used for the isotropic wavefield separation. Since applying these pseudo-derivative filter consumes high computational costs, we have developed the efficient anisotropic wavefield separation algorithm which has capability of parallel computing by using GPUs (Graphic Processing Units). In addition, the highly efficient anisotropic elastic reverse-time migration algorithm using MPI (Message-Passing Interface) and incorporating the developed anisotropic wavefield separation algorithm with GPUs has been developed. To verify the efficiency and the validity of the developed anisotropic elastic reverse-time migration algorithm, a VTI elastic model based on Marmousi-II was built. A synthetic multicomponent seismic data set was created using this VTI elastic model. The computational speed of migration was dramatically enhanced by using GPUs and MPI and the accuracy of image was also improved because of the adoption of the anisotropic wavefield separation.

• Tuberculosis and Respiratory Diseases
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• v.48 no.5
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• pp.766-772
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• 2000

Background : Pressure rise time (PRT) is the time in which the ventilator aclieves the set airway pressure in pressure-targeted modes, such as pressure control ventilation (PCV). With varying PRT, in principle, the peak inspiratory flow rate of the ventilator also varies. And if PRT is set to a shorter duration, the effective duration of target pressure level would be prolonged, which in turn would increase inspiratory tidal volume(Vti) and mean airway pressure (Pmean). We also postulated that the increase in Vti with shortening of PRT may relate inversely to the patients' basal airway resistance. Methods : In 13 paralyzed patients on PCV (pressure control 18$\pm$9.5 cm $H_2O$ $FIO_2\;0.6\pm0.3$, PEEP 5$\pm$3 cm $H_2O$, f 20/min, I : E1 : 2) with Servo 300 (Siemens-Elema, Solna, Sweden) from various causes of respiratory failure, PRT of 10 %, 5 % and 0 % were randomly applied. At 30 min of each PRT trial, peak inspiratory flow (PIF, L/sec), Vti (ml), Pmean (cm $H_2O$) and ABGA were determined. Results : At PRT 10%, 5%, and 0%, PIF were 0.69$\pm$0.13, 0.77$\pm$0.19, 0.83$\pm$0.22, respectively (p<0.001). Vti were 425$\pm$94, 439$\pm$101, 456$\pm$106, respectively (p<0.001), and Pmean were 11.2$\pm$3.7, 12.0$\pm$3.7, 12.5$\pm$3.8, respectively (p<0.001). pH were 7.40$\pm$0.08, 7.40$\pm$0.92, 7.41$\pm$0.96, respectively (p=0.00) ; $PaCO_2$ (mm Hg) were 47.4$\pm$15.8, 47.2 $\pm$15.7, 44.6$\pm$16.2, respectively (p=0.004) ; $PAO_2-PaO_2$ (mm Hg) were 220$\pm$98, 224$\pm$95, 227$\pm$94, respectively (p=0.004) ; and $V_n/V_T$ as determined by ($PaCO_2-P_E-CO_2$)/$PaCO_2$ were 0.67$\pm$0.07, 0.67$\pm$0.08, 0.66$\pm$0.08, respectively (p=0.007). The correlation between airway resistance and change of Vti from PRT 10% to 0% were r= -0.243 (p=0.498). Conclusion : Shortening of pressure rise timee during PCV was associated with increased tidal volume, increased mean airway pressure and lower $PaCO_2$.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.890-893
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• 1999

The intent of this paper is to describe a neural network structure called dynamic neural processor(DNP), and examine how it can be used in developing a learning scheme for computing robot inverse kinematic transformations. The architecture and learning algorithm of the proposed dynamic neural network structure, the DNP, are described. Computer simulations are demonstrate the effectiveness of the Proposed learning using the DNP.