• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.11
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• pp.1730-1736
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• 2001

A finite element analysis for a rotating cantilever beam is presented in this study. Based on a dynamic modeling method using the stretch deformation instead of the conventional axial deformation, three linear partial differential equations are (derived from Hamilton's principle. Two of the linear differential equations show the coupling effect between stretch and chordwise deformations. The other equation is an uncoupled one for the flapwise deformation. From these partial differential equations and the associated boundary conditions, two weak forms are derived: one is for the chordwise motion and the other is fur the flptwise motion. The weak farms are spatially discretized with newly defined two-node beam elements. With the discretized equations or the matrix-vector equations, the behaviors of the natural frequencies are investigated for the variation of the rotating speed.

• Journal of Chest Surgery
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• v.13 no.3
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• pp.298-300
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• 1980

The hamartoma is the most common benign tumor of the lung, but the incidence is very low. Most of hamartomas are revealed accidentally as coin lesion of routine chest X-ray because of no symptoms usually. The differential diagnosis should include tuberculoma, bronchogenic carcinoma, and other forms of tumor. Definitive diagnosis usually is established at exploratory thoracotomy. In this report, we present one case of a 42-year-old female having hamartoma of the left lower lobe of the lung that removed successfully and confirmed histopathologically. Her postoperative course was uneventful. She was discharged in good condition.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.773-778
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• 2002

The variance characteristics of the calcium carbonate contents along to the concrete cover depth takes the prediction method of remaining service life of concrete. Calcium carbonate contents were measured by the Thermo Gravimetric/Differential Thermal Analysis method at three point, depth of 0.25cm, 0.75cm, 1.25cm from the surface of concrete. This prediction method contain some assumption that the chemical protection conferred on steel is through a passive protective oxide film which forms on steel in an environment at or above a pH of 10.5$^{4)}$ .

• Journal of the Korean Mathematical Society
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• v.55 no.3
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• pp.705-717
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• 2018

We construct some infinite series of free and nearly free curves using pencils of conics with a base locus of cardinality at most two. These curves have an interesting topology, e.g. a high degree Alexander polynomial that can be explicitly determined, a Milnor fiber homotopy equivalent to a bouquet of circles, or an irreducible translated component in the characteristic variety of their complement. Monodromy eigenspaces in the first cohomology group of the corresponding Milnor fibers are also described in terms of explicit differential forms.

• Bulletin of the Korean Mathematical Society
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• v.53 no.2
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• pp.507-518
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• 2016

In this paper, using forms of conjugations, we give some algebraic properties of bicomplex numbers. We research differential operators, elementary functions and the analogous Cauchy-Riemann system in bicomplex number systems. Also, we investigate the definition and properties of regular functions with values in bicomplex settings in Clifford analysis.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.219.1-219.1
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• 2003

RNA polymerase II (pol II) is known to cycle between hyperphosphorylated and hypophosphorylated forms during transcription cycle. These extensive phosphorylation/dephosphorylation event occurs in the C-terminal domain (CTD) of the largest subunit of pol II which consists of a tandemly repeated heptapeptide motif with consensus of YSPTSPS. (omitted)

• Kyungpook Mathematical Journal
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• v.63 no.1
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• pp.105-122
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• 2023

We present explicit formulas for the spectra of higher spin operators on the subbundle of the bundle of spinor-valued trace free symmetric tensors that are annihilated by Clifford multiplication over the standard sphere in odd dimension. In the even dimensional case, we give the spectra of the square of such operators. The Dirac and Rarita-Schwinger operators are zero-form and one-form cases, respectively. We also give eigenvalue formulas for the conformally invariant differential operators of all odd orders on the subbundle of the bundle of spinor-valued forms that are annihilated by Clifford multiplication in both even and odd dimensions on the sphere.

• Journal of the Korean Society for Precision Engineering
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• v.3 no.3
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• pp.30-39
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• 1986

The burr worsens the accuracy of a workpiece and decreases a lot of pro- ductivity because it takes so much time and efforts to remove it. In this paper, the height, thickness and size of a drilling burr were derived from the drilling variables of drill diameter, chisel edge angle, web rate =($\Frac{2{\times}\;web\;thickness}{drill\;dia}$) and yielding stress of the workpiece as wel as feed, point angle and helix angle. The theoretical and experimental values of drilling thrust, torque and burr size of the testpiece were analyzed with the method of numerical analysis in a standard drilling condition. The order of choosing the drilling variables for the purpose of controlling the burr size was dealt in this paper with burr forming ratio. The results are as follows: (1) The drill diameter forms 42 percents feed 25 percents point angle 23 percents and web rate, chisel edge angle and gelix angle 5 percents of the partial differential slope of drilling thrust within the usual available ranges of drilling variables. (2) The drill diameter forms 55 percents feed 26 percents web rate 9 percents and chisel edge angle, point angle and helix angle 10 percents of the par- tial differential slope of drilling torque in the usual available ranges of drilling variables. (3) About 70 percents of the burr size can be controlled by feed, 29 percents by web rate in the case of a fixed diameter. It is recommended drilling10 variables to be chosen in the order of feed, web rate, drill diameter, point angle, chisel edge angle and helix angle so as to control the burr size effectively.

• Archives of Pharmacal Research
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• v.29 no.11
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• pp.1055-1060
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• 2006

The objective of this study was to formulate itraconazole semisolid dosage forms and characterize their physicochemical properties. Itraconazole and excipients such as polysorbate 80, fatty acids, fatty alcohols, oils and organic acids were melted at $160^{\circ}C$. The fused solution was then cooled immediately at $-10^{\circ}C$ to make wax-like semisolid preparations. Their physicochemical attributes were first characterized using differential scanning calorimetry, Fourier transform infrared spectroscopy and nuclear magnetic resonance spectrometry. The solubility of itraconazole in semisolid preparations and their dispersability in the simulated gastric fluid were also determined. Our semisolid preparations did not show any distinct endothermic peak of a crystalline form of itraconazole around $160-163^{\circ}C$. This suggested that it was changed into amorphous one, when it was formulated into semisolid preparations. In addition, the distinctive functional peaks and chemical shifts of itraconazole were well retained after processing into semisolid preparations. It could be inferred from the data that itraconazole was stable during incorporation into semisolid preparations by the hot melt technique. In particular, itraconazole semisolid preparations composed of polysorbate 80, fatty acids and organic acids showed good solubility and dissolution when dispersed in an aqueous medium. It was anticipated that the semisolid dosage forms would be industrially applicable to improving the bioavailability of poorly water-soluble drugs.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1190-1192
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• 1995

Poly(vinylidene fluoride)(PVDF) is one of the most studied polymers in the latest date. The interest in PVDF lies in its remarkable piezoelectric and pyroelectric properties. Also, PVDF has at least four known crystalline structures(; they are referred to as the ${\alpha},\;{\beta},\;{\gamma}\;and\;{\alpha}_p$ phase or forms II, I, III and $IV_p$). In this study, the manufactured PVDF thin film through vapor deposition method had form II(; the glass at $70^{\circ}C$). This thin film was investigated by x-ray diffraction(XRD), Fourier Transform Infrared(FT-IR) spectroscopy and Differential Thermal Analysis(DTA). XRD and FT-IR indicate crystallization forms from the glass at $70^{\circ}C$ into form II.