• Analytical Science and Technology
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• v.5 no.3
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• pp.309-317
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• 1992

Inorganic/organic composite was synthesized by using sol-gel process, and the bonding characteristics of composite was investigated with glass transition temperature(Tg), measured by DMTA(Dynamic Mechanical Thermal Analyzer). It was found from shift of Tg to higher temperature that composite reaction was proceeded better with the amount of HCl and water. But Tg was not varied with reaction time.

• Nuclear Engineering and Technology
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• v.34 no.6
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• pp.574-585
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• 2002

The microstructural characteristics and its related mechanical properties of RPV cladding have been investigated using small punch (SP) tests. SA508 Cl.3 RPV steel plates were overlay cladded with the type ER309L welding consumables by submerged arc welding process. Although the RPV clad material had a small portion of 5 ferrite phase, it still showed the ductile to brittle transition behavior The transition temperature was determined by the SP test and it depended on the content of $\sigma$ phase, specimen size, and determination methods. The fracture appearance of SP specimen was changed from circumferential to radial cracking as test temperature became low, and below the transition temperature region, ER309L cladding usually fractured along the 6 ferrite by the low temperature failure of ferrite phase.

• Proceedings of the IEEK Conference
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• 2002.06d
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• pp.381-384
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• 2002

In speech signal processing, it Is very important to detect the pitch exactly in speech recognition, synthesis and analysis. but, it is very difficult to pitch detection from speech signal because of formant and transition amplitude affect. therefore, in this paper, we proposed a pitch detection using the spectrum flattening techniques. Spectrum flattening is to eliminate the formant and transition amplitude affect. In time domain, positive center clipping is process in order to emphasize pitch period with a glottal component of removed vocal tract characteristic. And rough formant envelope is computed through peak-fitting spectrum of original speech signal in frequency domain. As a results, well get the flattened harmonics waveform with the algebra difference between spectrum of original speech signal and smoothed formant envelope. After all, we obtain residual signal which is removed vocal tract element The performance was compared with LPC and Cepstrum, ACF 0wing to this algorithm, we have obtained the pitch information improved the accuracy of pitch detection and gross error rate is reduced in voice speech region and in transition region of changing the phoneme.

• Journal of Korean Classical Literature and Education
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• no.15
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• pp.303-327
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• 2008

The purpose of this paper is the analysis of to point its structure and meaning deduced from the rite of passage. In the light of the rite of passage, could be retrieved its value as one of significant works among the works of Gangho-sijo. is composed of nineteen pieces of monotype sijo. The first piece is a kind of prologue. The other pieces are divided into three parts which correspond with the three stages of the rite of passage-separation, transition, incorporation. As a result of this analysis, we can find out the writer's cognitive change according to the schema of the rite of passage. It becomes clear that the space of Gangho means the sacred space for mental culture rather than a separate space for escape. And considering the withdrawal for Gangho as the transition process of the rite of passage, gives a description of the disentanglement of conflict and a incorporation into the superior position of spirit.

• Molecules and Cells
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• v.44 no.8
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• pp.569-579
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• 2021

Cyclase-associated protein 2 (CAP2) has been addressed as a candidate biomarker in various cancer types. Previously, we have shown that CAP2 is expressed during multi-step hepatocarcinogenesis; however, its underlying mechanisms in liver cancer cells are not fully elucidated yet. Here, we demonstrated that endoplasmic reticulum (ER) stress induced CAP2 expression, and which promoted migration and invasion of liver cancer cells. We also found that the ER stress-induced CAP2 expression is mediated through activation of protein kinase C epsilon (PKCε) and the promotor binding of activating transcription factor 2 (ATF2). In addition, we further demonstrated that CAP2 expression promoted epithelial-mesenchymal transition (EMT) through activation of Rac1 and ERK. In conclusion, we suggest that ER stress induces CAP2 expression promoting EMT in liver cancer cells. Our results shed light on the novel functions of CAP2 in the metastatic process of liver cancer cells.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.8
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• pp.1-9
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• 1999

Timing-level circuit analyses are used to obtain fast and accurate results, and the analysis of gate and interconnect delay is necessary to validate the correctness of circuit design. This paper proposes an efficient algorithm which simultaneously calculates the gate delay and the transition time of linearized voltage source for subsequent interconnect delay calculation. The notion of effective capacitance is used to calculate the gate delay and the transition time of linearized voltage source which considers the on-resistance of driving gate. The procedure for obtaining the gate delay and the transition time of linearized voltage source has been developed through an iterative operation using the precharacterized data of gates. While previous methods require extra information for the transition time calculation of linearized voltage sources, our method uses the derived data during the gate delay calculation process, which does not require any change in the precharacterization process.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.75-75
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• 2003

Transition of the resting primordial follicle to the growing primary follicle is a critical process for female reproduction, but its mechanism is poorly understood. The present study was conducted to investigate gene expression profile at the primordial-primary follicle transition process. We isolated total RNA of female mouse ovary at day1 (contains only primordial follicles) and day5 (contains primordial and primary follicles) and synthesized cDNA using annealing control primers (ACP; Seegene, Inc., Seoul, Korea). ACP provides annealing specificity and sensitivity to the template and allows to identify only authentic differentially expressed genes (DEGs). We used total 80 ACPs for PCR, observed PCR products on 2% agarose gel, cloned 42 DEGs using TOPO TA cloning vector, sequenced, and analyzed by BLAST search. Sequences of 34 clones significantly matched database entries while 4 clones were novel and 4 clones were EST. Two of 34 genes were specifically expressed only in day 5 ovaries (Sui1-rs1, Apg3p/Aut1p-like), and rest of 32 genes were expressed in both stages but were differential in amount. Differential expression was confirmed using semiquantitative RT-PCR, and there was no false positive. Anx11 and Pepp2-pending were highly expressed genes in day1-, while BPOZ, Ches1, Kcmf1, NHE3, Nid2, Ninj1, SENP3 and Survivin were highly expressed genes in day5-ovary. List of genes would provide insight for further study of mechanism regulating primordial-primary follicle transition.

• International Journal of Aeronautical and Space Sciences
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• v.6 no.2
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• pp.84-96
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• 2005

Helical tip vortex is known as stable vortex structure, however the specific frequency component of far wake perturbation induces the vortex pairing in hover and axial flight. It is expected that the tip vortex pairing phenomena may happen in transition flight and very low advance ratio flight so that inflow may be most nonuniform in the low advance ratio flight. The objectives of this paper are that a tip-vortex instability during the transition from hover into very low advance ratio forward flight is numerically predicted to understand a physics by using a time-marching free-wake method. To achieve the objectives, numerical method is firstly validated in typical axial and forward flights cases. Present scheme with trim routine can predict airloads and inflow distribution of forward flight with good accuracy. Then, the transition flight condition is calculated. The rotor used in this wake calculation is a small-scale AH-1G model. By using a tip-vortex trajectory tracking method, the tip-vortex pairing process are clearly observed in transient flight($\mu$=0.03) and disappears at a slightly higher advance ratio($\mu$=0.05). According to the steady flight simulation at $\mu$=0.03, it is confirmed the tip-vortex pairing process is continued in the rear part of rotor disk and not occurs in the front part. Time averaged inflow in this case is predicted as smooth distribution.

• Tribology and Lubricants
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• v.11 no.4
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• pp.21-27
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• 1995

The effects of interface boundary strength on wear and wear transition during sliding have been investigated in silicon carbide ceramics. Three different microstructures, i.e., solid state sintered silicon carbide, liquid phase sintered silicon carbide and liquid phase sintered silicon carbide composite reinforced with TiB$_{2}$ particulates, were designed by hot pressing. Examinations of crack patterns and fracture modes indicated that interface boundaries were relatively strong between silicon carbide grains in the solid state sintered silicon carbide, intermediate in the liquid phase sintered silicon carbide and weak between silicon carbide grains and TiB$_{2}$ particles in the composite. Wear data and examinations of worn surfaces revealed that the wear behavior of these silicon carbide ceramics could be significantly affected by the interface strength. In the solid state sintered silicon carbide, the wear occurred by a grooving process. In the liquid phase sintered silicon carbide and composite, on the other hand, an abrupt transition in wear mechanism from initial grooving to grain pull-out process occurred during the test. The transition occurred significantly earlier in the composite than in the carbide.

• International Journal of Naval Architecture and Ocean Engineering
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• v.13 no.1
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• pp.236-245
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• 2021

In this study, direct numerical and large eddy simulations of transitional flows around studs were conducted to investigate the effectiveness of turbulence stimulators at very low speeds for the minimum propulsion power condition of four knots. For simplicity, the studs were assumed to be installed on a flat plate, while the wake was observed up to 0.23 m downstream behind the second stud. For applicability to a model ship, we also studied the flow characteristics behind the first and second studs installed on a curved plate, which was designed to describe the geometry of a bulbous bow. A laminar-to-turbulent transition was observed in the wake at Re_D ≥ 921 (U_∞≥0.290 m/s), and the wall shear stress at Re_D = 1162 (U_∞ = 0.366 m/s) in the second wake was similar to that of the fully developed turbulent boundary layer after a laminar-to-turbulent transition in the first wake. At Re_D = 581 (U_∞ = 0.183 m/s), no turbulence was stimulated in the wake behind the first and second studs on the flat plate, while a cluster of vortical structures was observed in the first wake over the curved plate. However, a cluster of vortical structures was revealed to be generated by the reattachment process of the separated shear layer, which was disturbed by the first stud rather than directly initiated by the first stud. It was quite different from a typical process of transition, which was observed at relatively high Re_D that the spanwise scope of the turbulent vortical structures expanded gradually as it went downstream.