• 한국IT서비스학회:학술대회논문집
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• 2005.11a
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• pp.448-456
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• 2005

본 기고에서는 삼성SDS 컨설팅본부에서 새로 개발한 PFSS(PI for Six Sigma) 에 대해서 소개하고 PFSS방법론을 통해 프로세스 혁신(PI: Process Innovation)을 수행할 시 기대되는 효과에 대하여 알아본다. 우선 PFSS의 정의, 등장 배경 및 필요성에 대해서 논하였다. 그리고, PFSS 방법론의 Roadmap을 소개하고 Define - Measure - Analyze - Design - Optimize - Verify의 6개의 Phase에 대하여 알아본다. 마지막으로 PFSS의 장점 및 기대효과와 향후의 PFSS의 발전 방향에 대해 논하였다. 본 기고를 통해 기존의 프로세스 혁신 방법론과 6시그마 방법론이 어떻게 융합하여 상호 강점을 활용할 수 있는지를 살펴 볼 수 있는 기회가 되었으면 한다.

• Journal of Advanced Marine Engineering and Technology
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• v.7 no.1
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• pp.79-90
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• 1983

The examination for the changes of structures and mechanical properties in directionally solidified Al-Fe-Ni alloys containing the small amount of Fe and Ni was carried out by the varying the composition and solidification rate R of alloy, provided that the temperature gradient was 80 .deg.C/cm. The result were obtained as follows. A) In proportion to the increase of the solidification rate (R), the crystallized phase of this alloy was changed from the Ribbon-type structure to the Rod-type structure. B) The strength was rapidly increased in the changing process of composite shape from the Ribbon-type to the Rod-type with the solidification rate (R) increasing. C) The fiber stress (${\sigma}^f$) and Young's modulus ($E_f$) calculated for the Rod-type structure were 220 kg/$mm^2$ and 11, 800 kg/$mm^2$ respectively, which were in good accord with the rule of Mixtures.

• Bulletin of the Korean Chemical Society
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• v.21 no.12
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• pp.1187-1192
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• 2000

Ternary (Mo-Ru-Pd) and binary (Mo-Ru, Mo-Pd) alloys have been prepared using an Ar arc melting furnace. Mo and the noble metals, Ru and Pd, are the constituents of metallic insoluble residues, which were found in the early days of post-irradiation studies on uranium oxide fuels. In the present study, the structure of the alloys was evaluated using a powder X-ray diffractometer. Unit cell parameters were determined by least squares refinements of powder X-ray diffraction data. Scanning electron microscopic analyses of the surface of the alloys indicated that surface morphology was dependent on the crystallographic structure as well as its composition. Measurements of the magnetic susceptibility of the alloys showed evidence of superconducting transition from 3 to 9.2 K. Among the ternary and binary alloys, the ${\sigma}-phase$ showed the highest superconducting transition temperature,~9.2 K.

• Bulletin of the Korean Chemical Society
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• v.19 no.5
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• pp.533-539
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• 1998

A magnetic film was deposited on a slide glass substrate from aqueous solutions of $FeCl_2$ and $NaNO_2$ at 363 K. XRD analysis showed that the film was polycrystalline magnetite $(Fe_{3(1-{\sigma})}O_4)$ without impurity phase. The lattice constant was 0.8390 nm. Mossbauer spectrum of the film could be deconvoluted by the following parameters: isomer shifts for tetrahedral $(T_d)$ and octahedral $(O_h)$ sites are 0.28 and 0.68 mm/s, respectively, and corresponding magnetic hyperfine fields are 490 and 458 kOe, respectively. The estimated chemical formula of the film by the peak intensity of Mossbauer spectrum was $Fe_{2.95}O_4$. Low temperature transition of the magnetite (Verwey transition) was not detected in resistivity measurement of the film. Properties of the film were discussed with those of pressed pellet and single crystal of synthetic magnetites. On the surface of the film, magnetite particles of about 0.2 μm in diameter were identified by noncontact atomic force microscopy (NAFM) and magnetic force microscopy (MFM).

• Bulletin of the Korean Chemical Society
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• v.18 no.2
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• pp.208-212
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• 1997

Theoretical AM1 MO studies are reported on the gas-phase deprotonations of N-methyl 4-((Y-phenylsulfonyl)pyridinium cations (Ⅳ) and N-(Y-benzyl) 4-((phenylsulfonyl)methyl pyridinium cations (Ⅴ) using NH3 as a base. Bronsted α values for deprotonation of Ⅳ and Ⅴ are 0.18 and 0.17, respectively. Bronsted β value of 0.53 is found for the deprotonation of Ⅳ and Ⅴ by substituted aniline bases. The negative transition state (TS) imbalances, Ⅰ(=α-β) < 0, are rationalized by the negative distance factor, Δd (=dp-dTS) < 0, where dp and dTS are the distance between anionic charge center and substituents in the product and in the TS, respectively. The inability of d-pπ-conjugation in Ⅳ, where instead n-σ* type sigma delocalization occurs, causes very little lag in the structural reorganization in the TS.

• Proceedings of the Korean Society of Life Science Conference
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• 2000.06a
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• pp.3-8
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• 2000

The complete genome sequence of a Gram-positive bacterium .Bacillus subtilis has recently been reported and it is now clear that more than 50% of its ORFs have no known function (1). To study the global gene expression in B. subtilis at single gene resolution, we have tested the glass DNA microarrays in a step-wise fashion. As a preliminary experiment, we have created arrays of PCR products for 14 ORF whose transcription patterns have been well established through transcriptional mapping analysis. We measured changes in mRNA transcript levels between early exponential and stationary phase by hybridizing fluorescently labeled cDNA (with Cy3-UTP and Cy5-UTP) onto the array. We then compared the microarray data to confirm that the transcription patterns of these genes are well consistent with the known Northern analysis data. Since the preliminary test has been successful, we scaled up the experiments to ${\sim}$94% of the 4,100 annotated ORFs for the complete genome sequence of B. subtilis. Using this whole genomic microarray, we searched genes that are catabolite-repressive and those that are under the control of ${\sigma}^{Y}$, one of the functionally unknown ECF sigma factors. From these results, we here report that we have established DNA microarray techniques that are applicable for the whole genome of B. subtilis.

• Journal of Korea Foundry Society
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• v.26 no.2
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• pp.77-84
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• 2006

The effect of alloy composition on the glass forming ability (GFA) of the Ca-rich Ca-Mg-Zn alloys has been investigated in $Ca_{65}Mg_{5+x}Zn_{30-x}$ and $Ca_{55+x}Mg_{15}Zn_{30-x}$ (x=0, 5, 10, 15, 20) alloys. In a wide composition range of 15-25% Zn and 10-20% Mg bulk metallic glass (BMG) samples with the diameter larger than 6 mm are fabricated by conventional copper mold casting method in air atmosphere. Among the alloys investigated, the $Ca_{65}Mg_{15}Zn_{20}$ alloy exhibits the highest GFA enabling to form BMG sample with the diameter of at least 15 mm. The crystalline phase formed during solidification of $Ca_{65}Mg_{15}Zn_{20}$ ($D_{max}=15\;mm$) could be identified as a mixture of $Ca_3Zn$ and $CaMg_2$ cause by the redistribution of the constituent elements on long-range scale. The compressive fracture strength and fracture elongation of the $Ca_{65}Mg_{15}Zn_{20}$ BMG are 602 MPa and 2.08% respectively. The ${\sigma}$ parameter which has been recently proposed for evaluating GFA exhibits better correlation with GFA of Ca-Mg-Zn alloys than other parameters suggested so far such as ${\Delta}T_x$, $T_{rg}$, K, ${\gamma}$, and ${\Delta}T^*$ parameters.

• Korean Journal of Optics and Photonics
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• v.7 no.4
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• pp.434-439
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• 1996

To investigate influence of the incident beams which have the truncated Gaussian amplitude and of the shapes of bump on read-out signal is an optical disc, and the point spread function on bump, the scalar diffraction theory is used in this paper. We consider the truncated Gaussian amplitudes which are $\sigma$=0, 0.5, 1.5, and 2.5, the height of bump which is given by $n{\Delta}_0={\lambda}/4$, and the phase height of bump which is then given by ${\Phi}_0={\pi}$. We also consider the shapes of the bump which are a rectangular shape, a frustoconical shape, and a conical shape. It is shown that as the truncation of incident beam reduces the radius of central spot on bump decreases, the maximum value of read-out signal increases, and that the size of bump decreases. From these results, we get better read-out signal and the reduced cross-talk in optical disc when the truncation of incident beam reduces. Therefore a laser beam having less truncated Gaussian amplitude may useful for an actual optical disc.

• Applied Chemistry for Engineering
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• v.8 no.3
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• pp.416-424
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• 1997

Mass transfer mechanism and concentration profiles in the axial direction at each phase were analyzed and simulated by a theoretical modeling on a liquid-liquid static contactor using highly packed fiber bundle. The concentrations at the end of the fiber extractor calculated at several operational conditions were compared with experimental results. The fiber extractor could be completely predicted by a plug flow model without axial dispersion. A parameter used in the model equations, $k_a{\sigma}$ called the product of mass transfer coefficient and mass transfer area per unit length of the fiber extractor in the axial direction, which was determined by a curve-fitting, was confirmed to be a unique characteristic value of the fiber extractor, and was about 0.0327cm2/sec.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.12
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• pp.57-63
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• 2016

This paper describes implementation of the RF frequency synthesizer with $0.18{\mu}m$ silicon CMOS technology being used as an application of the IEEE802.15.4g SUN sensor node transceiver modules. Design of the each module like VCO, prescaler, 1/N divider, ${\Delta}-{\Sigma}$ modulator, and common circuits of the PLL has been optimized to obtain high speed and low noise performance. Especially, the VCO has been designed with NP core structure and 13 steps cap-bank to get high speed, low noise, and wide band tuning range. The output frequencies of the implemented synthesizer is 1483MHz~2017MHz, the phase noise of the synthesizer is -98.63dBc/Hz at 100KHz offset and -122.05dBc/Hz at 1MHz offset.