• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.6
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• pp.76-81
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• 2006

In this paper, profile error measurement method of a turbine blade using 3D-scanner is developed. The method begins with scanning the upper and lower sides of the blade on which three small balls are attached, and constructs a solid measurement model by registering the two scanned surfaces. Airfoils are derived from the model at each interval by intersecting it with a plane, and arranged with design airfoils. The $2^2$ factorial design search method is engaged in arranging the two airfoils, from which the main blade parameters including the edge radius are computed. The developed measurement technique is applied to practical blade manufacturing and validates its effectiveness.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1629-1632
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• 2008

Rapid, real-time detection of pathogenic microorganisms is an emerging and quickly evolving field of research, especially with regard to microorganisms that pose a major threat to public health. Herein, a new method that uses bioimpedance and solid culture medium for the real-time detection of microorganisms is introduced. We fabricated a new impedimetric biosensor by integrating solid media and two plane electrodes attached on two facing sides of an acryl well. During bioelectrical impedance analysis, the solid medium showed the characteristics of a homogenous conductive material. In a real-time impedance measurement, our solid-medium biosensor could monitor bacterial growth in situ with a detection time of ${\sim}4$ hrs. Our data indicate that the solid-medium biosensor is useful for detecting airborne microorganisms, thereby providing a new analytical tool for impedance microbiology.

• Economic and Environmental Geology
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• v.32 no.2
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• pp.161-167
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• 1999

Electric and electromagnetic surveys were conducted to investigate the deep structure of the Ulsan fault in Ipsil area, south of Kyeongju. On this study, especially high-frequency magnetotelluric method of electromagnetic survey in the frequency range of 10~100,000 Hz was mainly employed to study the deep subsurface configuration. High-frequency MT survey was performed at 70 points of spacing 30~50 m, making 3.8 km survey line. As a survey result, a 2-km-depth 2-D cross-section was achieved. It shows vertical and horizontal subsurface variations of resistivity values. Near-surface layer having low resistivity value becomes thicker eastward up to 800m. There is a steep low resistivity zone in the west side of survey line, and there exists two low resistivity zones dipping west in the east side of survey line. Two low resistivity zones are interpreted to be related to major movement pattern of the Ulsan fault. This suggests that major fault lines are developed on both peripheral sides of the broad fault zone.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.12
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• pp.3094-3104
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• 1993

The five punch and die sets are selected as the examples of arbitrary cross sections which have two opposite inclined sides. Two kinds of blank shapes are designed for all cross sections. One(h-b1.) is determined by slip-line theory and the other (G-b1.) is determined conventionally as the similar shapes with the cross sections which were used by Gopinathan. As a result of the experimental procedures, the superiority of the blank shapes designed by slip-line theory is verified in the limiting drawing ratio, the uniformity of cup height and the thickness distributions.

• Proceedings of the Membrane Society of Korea Conference
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• 1993.04a
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• pp.25-27
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• 1993

Multiphase equilibrium-based processes for separation and purification generally utilize dispersed systems in which one phase is dispersed in the other as bubbles or drops or thin films. Using microporous membranes, novel techniques have been developed such that multiphase processes can now be carried out in a nondispersive fashion for gas-liquid (Sirkar, 1992) and liquid-liquid (Prasad and Sirkar, 1992) contacting processes. Among such processes, only nondispersive solvent extraction of pollutants using microporous membranes will be of concern here. These processes employ immobilized immiscible phase interfaces at the pore mouths in a microporous membrane. Through such interfaces, solutes are extracted into the solvent as two immiscible phases flow on two sides of a microporous membrane. Many advantages of such a technique over conventional dispersion-based extractors have been summarized (Prasad and Sirkar, 1992).

• Journal of Industrial Technology
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• v.20 no.B
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• pp.169-174
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• 2000

The most of metalhalide lamps is what the momentary restarting cannot be realized when the arc tube is in the hot condition. The discharge starting voltage of arc tube in the hot condition is much higher than in the cold condition in proportion to the gaseous pressure. Therefore it takes about ten minutes to restart the metal Halide lamps, that is to say, it is possible to start when the pressure and the temperature are decreased. But, if the lamp is restarted in the hot condition, we must supply the high voltage pulse with 15kV between the both electrodes of lamp. The proposed ignitor has two ignitors. If we connect each ignitor at the both sides, the high voltages of two different frequencies are generated. If so, when the one of the ignitor generates the highest voltage and the other applied to elecrodes of the lamp. In this way, we can restart the lamp with the voltage 15kV, even if the lamp is in the hot condition.

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.176-178
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• 1999

The Synchronous Reluctance Motor(SynRM) was made and experimented. Salient type SynRM was manufactured by cutting two sides of the three phase squirrel case rotor. So this prototype motor has same stator and capability with the counterparts of the induction motor. The airgap flux density, inductance and torque characteristics was inspected by Finite Element Analysis (FEA). The static torque experiments was accomplished. The paper proposed the effect of rotor bar by comparing two models.

• Animal Systematics, Evolution and Diversity
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• v.4 no.2
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• pp.91-102
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• 1988

Both Cobitis lutheri Rendahl and C.striata Ikeda previously regarded as the subspecies of C.taenia are revised here and raised to the species rank based on the distinct color pattern on their body sides in relation to the shpae of lamina circularis and suborbital spine, and distinct distributional patter. C. lutheri was similar to C. striata in chromosome number and karyotype, but chromosomal polymorphism as Robert sonian event was confirmed only in the population of C.lutheri studies. Both, C. kutheri and C..striata have disjunct ranges : the former in western Korea and east-northern China Mainland, the latter in the Smjin River of korea and west-southern Japan. hybridization between C. lutheri and C. striata by secondary contact appeared in the limited zone of the Dongjin River, Chllabuk-do province, korea, but the evidence for habitat segregation between them suggests the possibility that natural hybridization occurs between the two species and introgression results. We consider that the two species were produced as ecological equivalent species in the different branch stream of the Paleo-Hwangho River , The time of recession of sea level during the gracial period.

• Earthquakes and Structures
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• v.2 no.2
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• pp.109-126
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• 2011

The inelastic earthquake response of non-symmetric, braced steel buildings, designed according to the EC3 (steel structures) and EC8 (earthquake resistant design) codes, is investigated using 1, 3 and 5-story models, subjected to a set of 10, two-component, semi-artificial motions, generated to match the design spectrum. It is found that in these buildings, the so-called "flexible" edge frames exhibit higher ductility demands and interstory drifts than the "stiff" edge frames. We note that the same results were reported in an earlier study for reinforced concrete buildings and are the opposite of what was predicted in several other studies based on the over simplified, hence very popular, one-story, shear-beam type models. The substantial differences in such demands between the two sides suggest a need for reassessment of the pertinent code provisions. In a follow up paper, a design modification will be introduced that can lead to a more uniform distribution of ductility demands in the elements of all building edges. This investigation is another step towards more rational design of non-symmetric steel buildings.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2534-2536
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• 2001

The most of metalhalide lamp is what the momentary restarting cannot be realized when the arc tube is in the hot condition. But if the lamp is restarted in the hot conditidn, we must supply the high voltage pulse with 15kv between the both electrodes of lamp. The proposed ignitor has two ignitors. If we connect each ignitor at the both sides, the high voltages of two different frequencies are generated. if so, when the one of the ignitor generates the highest voltage and the other applied generates the lowest voltage. At this time, the widest difference of voltage is applied to electrodes of the lamp. In this way, we can restart the lamp with the voltage 15kv, even if the lamp is in the hot condition.