• Bulletin of the Korean Mathematical Society
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• v.29 no.1
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• pp.9-13
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• 1992

In this paper, we consider the function related with almost hermitian structure on a copact complex manifold. More precisely, on a 2n-diminsional complex manifold M admitting 2-form .ohm. of rank 2n everywhere, assume that M admits a metric g such that g(JX, JY)=g(X,Y), that is, assume that g defines an hermitian structure on M admitting .ohm. as fundamental 2-form-the 'almost complex structure' J being determined by g and .ohm.:g(X,Y)=.ohm.(X,JY). We consider the function I(g):=.int.$_{M}$ $N^{2}$d $V_{g}$, where N is the norm of Nijenhuis tensor N defined by (J,g). by (J,g).

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1269-1270
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• 2006

Mg-Zn-RE alloys had a novel lond period stacking ordered (LPO) structure. Their rapidly solidified powder metallurgy (RS P/M) alloys exhibited a combination of high strength and god ductility (tensile yield strength above 550 MPa and elongation above 5%). The LPO Mg-Zn-RE RS P/M alloys had high elevated temperature strength (tensile yield strength above 380 MPa at 473 K) and exhibited a high-strain-rate superplasticity at higher temperatures. In Japan, a national project for developing high strength LPO Mg-Zn-RE RS P/M alloys has started at 2003 for 5 years, which is founded by the Ministry of Economy, Trade and Industry (METI) of Japan. In the national project, project targets in materials performances have been achieved. The developed LPO Mg-Zn-RE RS P/M alloys exhibited higher tensile yield strength, fatigue strength and corrosion resistance than high strength aluminum alloys of extra-super-duralumin (7075-T6).

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.2
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• pp.53-58
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• 2004

In this paper, the low-phase dual-band VCO, by adding switching circuit with PIN diode at feedback loop of the oscillation part having negative-resistance, is realized. In order to reduce the phase noise of the VCO, PBG structure applied to the ground plane of the resonator. When applying for PBG structure, output power is -9.17㏈m and phase noise is -102㏈c/Hz at 5.25㎓, output power is -5.17㏈m and phase noise is -101㏈c/Hz at 1.8㎓, respectively.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.602-603
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• 2006

Micro-porous nickel (Ni) with an open cell structure was fabricated by powder metallurgy. The pore size of the micro-porous Ni approximated $30{\mu}m$ and $150{\mu}m$. For comparison, porous Ni with a macro-porous structure were also prepared by both powder metallurgy (pore size $800{\mu}m$) and the traditional chemical vapour deposition method (pore size $1300{\mu}m$). The mechanical properties of the micro-and macro-porous Ni samples were evaluated using compressive tests. Results indicate that the micro-porous Ni samples exhibited significantly enhanced mechanical properties, compared to those of the macro-porous Ni samples.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.8
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• pp.1461-1465
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• 2007

A micromachined sensor part for an infrared focal plane array has been designed and fabricated. Amorphous silicon was adapted as a sensing material, and silicon nitride was used as a membrane material. To get a good efficiency of infrared absorption, the sensor was made as a ${\lambda}/4$ cavity structure. All the processes were done in $0.5\;{\mu}m$ iMEMS fab. in the Electronics and Telecommunication Research Institute (ETRI). The processed MEMS sensor structure had a small membrane deflection less than $0.3\;{\mu}m$. This excellent deflection property can be attributed to the rigorous balancing of the stresses of individual layers. The efficiency of infrared absorption was more than 75% in the wavelength range $8\;-\;14\;{\mu}m$.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.83.2-83.2
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• 2019

We study the stability of the magnetic structure in active region (AR) 12371 producing an M6.5 flare on June 22 2015. We first perform a nonlinear force-free fields (NLFFFs) extrapolation to derive three-dimensional (3D) magnetic fields based on time series of observed photospheric magnetic fields. The NLFFFs well describe an observed sigmoidal structure with the shape of a double arc magnetic configuration. Next, we examine three possible instabilities (kink, torus, and double arc) to investigate how the M6.5 flare is triggered in the double arc loops. Consequently, the double arc loops are stable against kink and torus instabilities, but possibly unstable against the double arc instability before the flare occurrence. Finally, we discuss a probable scenario for the M6.5 flare.

• Kyungpook Mathematical Journal
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• v.60 no.2
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• pp.223-238
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• 2020

We study a lightlike hypersurface M of an indefinite nearly trans-Sasakian manifold ${\bar{M}}$ with an (ℓ, m)-type connection such that the structure vector field ζ of ${\bar{M}}$ is tangent to M. In particular, we focus on such lightlike hypersurfaces M for which the structure tensor field F is either recurrent or Lie recurrent, or such that M itself is totally umbilical or screen totally umbilical.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.1
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• pp.61-64
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• 1994

The NMOSFET with gate length of 0.1$\mu$m is fabricated by mix-and-match method. In this device, the electron beam lithography is used to form the gate layer, while other layers are formed by the stepper. The gate oxide is 7nm thick, and the device structure is normal LDD structure. The saturation Gm for gate length of 0.1$\mu$m is 246mS/mm. The subthreshold slope is 180mV/decade for 0.1$\mu$m gate length, but the slope is 80mV/decade for 0.3$\mu$m gate length.

• BMB Reports
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• v.33 no.2
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• pp.120-125
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• 2000

M2PI is an active single chain mini-proinsulin with a 9-residue linker containing the turn-forming sequence 'YPGDV' between the B- and A-chains, but which retains about 50% of native insulin receptor binding activity. The refolding efficiency of M2PI is higher than proinsulin by 20-40% at alkaline pH, and native insulin is generated by the enzymatic conversion of M2PI. The solution structure of M2PI was determined by NMR spectroscopy. The global structure of M2PI is similar to that of native insulin, but the flexible linker between the B- and A-chains perturbed the N-terminal A-chain and C-terminal B-chain. The helix in the N-terminal A-chain is partly perturbed and the ${\beta}$-turn in the B-chain is disrupted in M2PI. However, the linker between the two chains was completely disordered indicating that the designed turn was not formed under the experimental conditions (20% acetic acid). Considering the fact that an insulin analogue, directly cross-linked between the C-terminus of the B-chain and the N-terminus of the A-chain, has negligible binding activity, a flexible linker between the two chains is sufficient to keep binding activity of M2PI, but the perturbed secondary structures are detrimental to receptor binding.

• Korean Journal of Ichthyology
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• v.13 no.1
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• pp.19-23
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• 2001

The full-grown oocyte envelope of the two spined loaches, Niwaella multifasciata and Kichulchoia brevifasciata, was examined by electron microscopy. The oocyte is surrounded by its envelope, and an external modification (an adhesive structure) in the surface of the envelope is present. The envelope consists of two layers, a zona radiata externa which is the site of the adhesive structure, and a zona radiata interna, which has heterogeneous, electron-dense multi layers. The surface (zona radiata externa) of the envelope in N. multifasciata is equipped with short villuslike protuberances, which have a length of 1.5~2.5 ${\mu}m$ and are separated from each other by a distance of 2~2.5 ${\mu}m$. In contrast, K. brevifasciata has undulating or wave-like structures that extend over the entire oocyte surface. The waves are 1.5~2.5 ${\mu}m$ in length and are separated a distance of 2.5~3.3 ${\mu}m$ from each other.