• Proceedings of the KWS Conference
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• 2002.10a
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• pp.193-198
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• 2002

In 1his paper, applicability of laser welding to joining process of single crystal nickel base superalloy turbine blades was investigated. Because heat input of laser welding is more precisely controlled 1han TIG welding, it is possible to optimize solidification microstructure of the welds. Since in single crystal nickel base superalloy the crystal orientation have a significant effect on the strength, it is important to control the solidification microstructure in the fusion zone. A single crystal nickel base supera1loy, CMSX-4, plates were bead-on welded and butt welded using a $CO_2$ laser. The effects of microstructure and crystal orientation on properties of the weld joints were investigated. In bead-on weldling, welding directions were deviated from the base metal [100] direction by 0, 5, 15 and 30 degrees. The welds with deviation angles of 15 and 30 degrees showed fusion zone transverse cracks. As the deviation angles became larger, the fusion zone had more cracking. In the cross section microstructure, the fusion zone grains in 0 and 5 degrees welds grew epitaxially from the base metal spins except for the bead neck regions. The grains in the bead neck regions contained stray crystals. As deviation angles increased, number of the stray crystals increased. In butt welding, the declinations of the crystal orientation of the two base metals varied 0, 5 and 10 degrees. All beads had no cracks. In the 5 degrees bead, the cross section and surface microstructures showed that the fusion zone grains grew epitaxially from the base metal grains. However, the 10 degrees bead, the bead cross section and surface contained the stray crystals in the center of the welds. Orientations of the stray crystals accorded with the heat flow directions in the weld pool. When the welding direction was deviated from the base metal [100] direction, cracks appeared in the area including the stray crystals. The cracks developed along the grain boundaries of the stray crystals with high angles in the final solidification regions at the center of the welds. The fracture surfaces were covered with liquid film. The cracks, therefore, found to be solidification cracks due to the presence of low melting eutectic. As the results, in both bead-on welding and butt welding the deviation angles should be control within 5 degrees for preventing the fusion zone cracks. To investigate the mechanical properties of the weld joints, high temperature tensile tests for bead-on welds with deviation angles of 0 and 5 degrees and the butt welds with dec1ination angles of 0, 5 and 10 degrees were conducted at 1123K. The the tensile strength of all weld joints were more 1han 800MPa that is almost 80% of the tensile strength of the base metal. The strength of the laser weld joints were more than twice that of tue TIG weld joints with a filler metal of Inconel 625. The results reveals 1hat laser welding is more effective joining process for single crystal nickelbase superalloy turbine blades 1han TIG welding.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.1
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• pp.21-28
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• 2000

Although commercial PIV systems have been widely used for the non-intrusive velocity field measurement of fluid flows, they are still under development and have considerable room for improvement. In this study, a single-frame double-exposure PIV system using a high-resolution CCD camera was developed. A pulsed Nd:Yag laser and high-resolution CCD camera were synchronized by a home-made control circuit. In order to resolve the directional ambiguity problem encountered in the single-frame PIV technique, the second particle image was genuinely shifted in the CCD sensor array during the time interval dt. The velocity vector field was determined by calculating the displacement vector at each interrogation window using cross-correlation with 50% overlapping. In order to check the effect of spatial resolution of CCD camera on the accuracy of PIV velocity field measurement, the developed PIV system with three different resolution modes of the CCD camera (512 ${\times}$ 512, lK ${\times}$ IK, 2K ${\times}$ 2K) was applied to a turbulent flow which simulate the Zn plating process of a steel strip. The experimental model consists of a snout and a moving belt. Aluminum flakes about $1{\mu}m$ diameter were used as scattering particles for the liquid flow in the zinc pot and the gas flow above the zinc surface was seeded with atomized olive oil with an average diameter of 1-$3{\mu}m$. Velocity field measurements were carried out at the strip speed $V_s$=1.0 m/s. The 2K ${\times}$ 2K high-resolution PIV technique was significantly superior compared to the smaller pixel resolution PIV system. For the cases of 512 ${\times}$ 512 and 1K ${\times}$ 1K pixel resolution PIV system, it was difficult to get accurate flow structure of viscous flow near the wall and small vortex structure in the region of large velocity gradient.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.4
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• pp.385-390
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• 1997

Fifteen Ettawah-cross does were used to study maternal serum concentrations of total triiodothyronine ($T_3$), teraiodothyronine ($T_4$) and cortisol in different status of pregnancy (nonpregnant, aborted, single and twin-bearing does) during late pregnancy. Analysis of the data indicated that here was no significant changes in total $T_3$, $T_4$, and cortisol concentrations with the advance of pregnancy. Concentrations of $T_3$, $T_4$, and cortisol decreased by 38.9, 34.9, and 32.6%, and 12.0, 15.7 and 27.6%, and 41.6, 44.0, and 43.7% in the aborted, single and, twin-bearing, respectively, as compared to those nonpregnant does. These was no significant difference in concentrations of $T_3$ and cortisol between aborted, single and twin-bearing does, and in those of $T_4$ between aborted and single-bearing does. However, $T_4$ concentrations in twin-bearing were lower by 17.7 and 14.1% than those in aborted and single-bearing does, respectively. The decreased concentrations of thyroid hormones in pregnant does suggested that fetus could have increased iodine uptake from maternal circulation causing a decrease in the availability of this nutrient for synthesis of maternal thyroid hormones. The decreased concentrations of cortisol could have been associated with the increased metabolism of the hormone to regulate nutrients influx into the placenta of pregnant does.

• Cross-Cultural Studies
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• v.46
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• pp.43-61
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• 2017

This essay interprets envy not as a form of conventional conflict between women but as a type of common response of self-preservation focused on envy represented in the American film, Single White Female, and the Korean film, Female Teacher. Although envy is traditionally classified as a feminine emotion, it is an innate human emotion regardless of gender identity. Especially in the competitive era of neo-liberalism, we recognize only its negative side while overlooking its positive side as envy originates from comparison with others. Hedy's mimicking of Allie in Single White Female is not the same as idealized identification because her envy is aggressive and a self-assertive response while transforming Allie's identity. Likewise, envy of a protagonist in Female Teacher triggers an action of self-preservation against irrational social and personal inequality. Accordingly, a type of resistant and critical power resides in envy between women in these films. Therefore, proper recognition of repressed envy is required in order to prevent its transition towards a violent outcome.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.1
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• pp.13-22
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• 2022

In this paper, we propose single and array antenna with dual linear polarization characteristics for 28 GHz band. The proposed antenna is designed two microstirp feeding structure and Taconic TLY-5 substrate, which is thickness 0.5 mm, and the dielectric constant is 2.2. The size of single patch antenna is 3.4 mm×3.4 mm, and total size of single antenna is 15.11 mm×15.11 mm. Also, the size of array antenna is 3.15 mm×3.15 mm, and total size of array antenna is 21.5 mm×13.97 mm. From the fabrication and measurement results, for 1×2 array antenna, in case of vertical polarization, cross polarization ratios are obtained from 14.23 dB to 20.79 dB and in case of horizontal polarization, cross polarization ratios are obtained from 14.31 dB to 22.74 dB for input port 1. in case of vertical polarization, cross polarization ratios are obtained from 15.75 dB to 25.88 dB and in case of horizontal polarization, cross polarization ratios are obtained from 14.70 dB to 22.82 dB for input port 2.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.315-320
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• 2000

An investigation and structural safety analysis was conducted to get the basic data for establishing maintenance strategy of pipe framed greenhouses. The number of greenhouses investigated was 108 in total. Most multi-span greenhouses had narrower width and lower height than the standard 1-2W greenhouse, and most of single-span greenhouses were tunnel type. In multi-span greenhouses, the size and interval of frameworks such as rafter, purline, column, and cross beam were mostly suitable, but frameworks of single-span greenhouses were mostly insufficient.

• Proceedings of the Materials Research Society of Korea Conference
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• 2006.11a
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• pp.31.2-31.2
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• 2006

• Archives of Plastic Surgery
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• v.32 no.4
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• pp.539-542
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• 2005

Reconstructions of soft tissue defect of the posterior ankle including Achilles the tendon should take into account not only coverage but functional outcome. Various methods of tendon transfer and tendon graft have been reported as a single-stage procedure. With advances and refinements in microsurgical techniques, several free composite flaps including tendon, fascia, or nerve have been used in single-stage reconstructions of large defects in this area minimizing further damage to the traumatized leg. However, when free flap is not feasible for some reasons, this cannot be accomplished successfully. Here we present a patient with Achilles tendon and circumferential large soft tissue defect. Because of circulatory compromise of the lower extremity, free flap reconstruction could not be applied. Instead, cross-leg composite flap of the dorsalis pedis flap including the extensor hallucis brevis musle and tendon, and tendon strips of the Second, third and fourth extensor digitorum logus were employed, Functional reconstruction of the tendon and resurfacing were obtained at the same time. The flap was detached 3 weeks postoperatively, and the transplanted flap has survived without any complications. By 3 months after surgery, full weight bearing, tip-toe standing and even walking without crutch assistance was possible. When functional reconstruction with the free flap is unattainable in the large defect of the posterior ankle including the Achilles tendon, cross-leg composite island flap of dorsalis pedis flap and tendon strips of the extensor digitorum longus tendon is a viable alternative.

• Nuclear Engineering and Technology
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• v.48 no.2
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• pp.482-494
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• 2016

The Feshbache-Kermane-Koonin (FKK) multi-step direct (MSD) theory of pre-equilibrium reactions has been used to compute the single-step cross-sections for some (p,${\alpha}$) reactions using the knock-on and pick-up reaction mechanisms at two incident proton energies. For the knock-on mechanism, the reaction was assumed to have taken place by the direct ejection of a preformed alpha cluster in a shell-model state of the target. But the reaction was assumed to have taken place by the pick-up of a preformed triton cluster (also bound in a shell-model state of the target core) by the incident proton for the pick-up mechanism. The Yukawa forms of potential were used for the proton-alpha (for the knock-on process) and proton-triton (for the pick-up process) interaction and several parameter sets for the proton and alpha-particle optical potentials. The calculated cross-sections for both mechanisms gave satisfactory fits to the experimental data. Furthermore, it has been shown that some combinations of the calculated distorted wave Born approximation cross-sections for the two reaction mechanisms in the FKK MSD theory are able to give better fits to the experimental data, especially in terms of range of agreement. In addition, the theory has been observed to be valid over a wider range of energy.

• Journal of the Korea Safety Management & Science
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• v.19 no.3
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• pp.129-135
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• 2017

The respective delivering vehicle loaded with the own cargo moves into the respective delivery area. At the base, the delivery points D1 and D2, for example, have the same starting point but the destination is different. The average delivering time of the delivery vehicle is mostly more than 8 hours a day. Therefore, the efficiency of delivery is generally low. In this study, the deliveries will be forwarded from a base station to a delivery point where cross docking will be applied to a single vehicle, and will be distributed from the cross docking point through cross docking. If the distribution is implemented, one vehicle will not have to be operated from the base to the cross docking point. In that case, logistics cost will be reasonably saved by the reduction of transportation cost and labor time. If one vehicle only runs from the base to the cross docking point, each vehicle will be operated in two shifts, and the vehicle operation can be efficiently implemented. This research model is based on the assumption that the 3 types of ratios between the traffic volume of the vehicles starting at the base and the vehicles waiting at the cross docking point are set to the first ratio of 30% to 70%, the second ratio of 50% to 50% and the final ratio of 70% to 30%. As a result of the study, The delivery time in the cross docking point is much higher than that in present on the condition that the cargo volume in the D2 area is more than 50%. Likewise, the delivery time is slightly higher on the condition that the cargo volume is less than 50%. Time is reduced in terms of 50% model like AS-IS model.