• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.1
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• pp.203-211
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• 1994

An experiment was carried out to evaluate the heat transfer and pressure drop performances of the smooth tube and two augmented tubes using R-113 under horizontal condensation condition. The augmented tubes are a spirally-twisted tube and an internally-finned tube. The test tube is 13.88 mm in diameter and 3.2 m long. Five different inlet pressure of 0.13, 0.16, 0.18, 0.21 and 0.23 MPa were employed and the mass flux was varied from 80 to 265 $kg/m^{2}s.$ The results showed that the overall heat transfer coefficient for the spirally-twisted tube and internally-finned tube were enhanced by 30-85% and 130-180%, respectively, over that for the smooth tube. The increase in total pressure drop for the spirally-twisted tube and internally-finned tube were reached up to 250-350% and 1100-1600%, respectively, over that for the smooth tube. Correlations were proposed for predicting the condensation heat transfer coefficient for the smooth tube and two augmented tubes.

• Honam Mathematical Journal
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• v.32 no.4
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• pp.563-579
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• 2010

In this paper we introduce the new analogs of Genocchi numbers and polynomials. Finally, we investigate the zeros of the twisted (h,q)-extension of Genocchi polynomials ${G_{n,q,w}^{(h)}}$(x).

• Bulletin of the Korean Mathematical Society
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• v.53 no.1
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• pp.273-301
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• 2016

In this paper, we classify all twisted torus knots which are doubly middle Seifert-fibered. Also we show that all of these knots possibly except a few admit Dehn surgery producing a non-Seifert-fibered graph manifold which consists of two Seifert-fibered spaces over the disk with two exceptional fibers, glued together along their boundaries. This provides another infinite family of knots in $S^3$ admitting Dehn surgery yielding such manifolds as done in [5].

• Bulletin of the Korean Mathematical Society
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• v.50 no.2
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• pp.659-665
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• 2013

In this note, the $q$-extension of the twisted Lerch Euler zeta functions considered by Jang [Bull. Korean Math. Soc. 47 (2010), no. 6, 1181-1188] is further investigated, and the generalized multiplication theorem for the $q$-extension of the twisted Lerch Euler zeta functions is given. As applications, some well-known results in the references are deduced as special cases.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.1092-1095
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• 2003

A driving mechanism and excellent features for an in-plane switching twisted nematic liquid crystal mode (IT mode) that could possibly improve the viewing-angle and color shift characteristics and the cell gap error tolerance is proposed. .It is important that the surface azimuthal anchoring strength of the liquid crystal cell differs at the upper and lower substrates. Furthermore. as a rubbing-free LCD. amorphously aligned in-plane switching twisted nematic mode (a-IT mode) is also demonstrated.

• Journal of applied mathematics & informatics
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• v.39 no.1_2
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• pp.1-11
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• 2021

In this paper, we define degenerate Carlitz-type twisted q-Euler numbers and polynomials by generalizing the degenerate Euler numbers and polynomials, Carlitz's type degenerate q-Euler numbers and polynomials. We also give some interesting properties, explicit formulas, symmetric properties, a connection with degenerate Carlitz-type twisted q-Euler numbers and polynomials.

• Journal of KIISE:Computer Systems and Theory
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• v.37 no.2
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• pp.61-65
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• 2010

The twisted cube has received great attention because it has several superior properties to the hypercube that is widely known as a versatile parallel processing system. In this paper, we show that node-disjoint $2^{n-1}$ meshes of size $2^n{\times}2^m$ can be embedded into a twisted cube with dilation 1 where $1{\leq}n{\leq}m$. The expansion is 1 for even m and 2 for odd m.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.1
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• pp.10-21
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• 2010

Equations of chordwise and flapwise bending motions for the vibration analysis of rotating pre-twisted blades having tapered cross section and setting angle are derived by using hybrid deformation variable modeling. The two motions are couples to each other due to the pre-twisted angle of the beam cross section. The derived equations are transformed into dimensionless forms in which dimensionless parameters are identified. The effects of the dimensionless parameters on the modal characteristics of rotating pre-twisted blades having tapered cross section and orientation angle are investigated. The eigenvalue loci veering phenomena are also investigated and discussed in this work.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.288-288
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• 2009

We have studied polarity effects of dielectric anisotropy effects on electro-optical characteristics of a twisted nematic mode driven by fringe electric field, which has wide viewing angle characteristics. Our device is designed as normally black mode between parallel polarizers. The perfect polarization conversion of incident light, which passes through a polarizer, is achieved, when it passes through the twisted liquid crystal (LC) layer. If an electric field is applied, the LC molecules with a positive (or negative) dielectric anisotropy rotate parallel (or perpendicular) to the horizontal component of a fringe electric field as increasing transmittance. From the calculated results, enhanced transmittance of the fringe field-twisted nematic (FF-TN) mode with positive dielectric anisotropy of + 8.2 can be obtained.

• KSTLE International Journal
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• v.2 no.1
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• pp.59-64
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• 2001

A new bearing concept, the wave journal bearing, has been developed to improve the static and dynamic performance of a hydrodynamic journal bearing. This concept features a wave in bearing surface. Not only straight but also twisted wave journal bearings are investigated numerically. The performances of straight and twisted bearings are compared to a plain journal bearing over a wide range of eccentricity. The bearing load and stability characteristics are dependent on the geometric parameters such as the number of waves, the amplitude and the starting point of the wave relative to the applied load direction. The bearing performance is analyzed for various configurations and for both cases of smooth and wave member notation. The wave journal bearing, especially for the twisted one, offers better stability than the plain journal bearing under all eccentricity ratios and load orientation.