• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.3
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• pp.328-335
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• 2009

In order to 1ransport the steel roll coil effectively and safely to the destination, the stability of the steel roll coil which induced the minimum movements during the 1ransportation was s1rongly required. The basic 1ransportation equipment for the steel roll coil such as the wedge is made of 100% imported wood known as the apitong. However, the material characteristic such as the rigidity has caused permanent damages to the steel roll coil and the damaged steel roll coils were not easily restorable. Thus it was unsuitable for other purposes. The introduction of new materials to manufacturing wedges which would have a good recovery performance and thus enable the wedge prevention or reduction to the steel roll coil or any other products during the 1ransportation is needed. Due to the fact that recovering damage of the coil is almost impossible, we have to find the new type of wedge that can substitute the apitong wedge. Therefore, we are going to develop a wedge that does not damage rolled steel coil and has better recovery and softness than existing apitong wedge.

• Journal of the Society of Naval Architects of Korea
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• v.34 no.3
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• pp.70-75
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• 1997

This paper concerns with a safe and efficient transportation method of hot-coils on cargo ship. An automatic loading and unloading system of hot-coils by cassettes, which secure the geometrically unstable cargo, hot-coil, by supporting with wedges on both sides, is considered efficient and profitable. Safety of hot-coil on cassette and subsequently safety of total cargo ship are directly affected by the wedge angle of cassette. For optimal design of the cassette wedge angle, a dynamic model of hot-coil/cassette cargo is developed with constraint of no relative motions between the coil and the cassette. Force equilibrium conditions between resultant alternating inertia forces on hot-coil due to motions of cargo ship in waves and reactions forces from cassette wedge surfaces are derived and consequently a numerical simulation code is implemented. Cassette wedge angle of 37 degree is taken as optimal by considering dynamic stability of hot-coil and strength of cassette structure. Performance of the designed cassette wedge angle is investigated by scaled bench test.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.249-249
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• 2006

We have prepared an amphiphilic wedge-coil molecule consisting of a hydrophobic wedge-like segment and a hydrophilic poly(ethylene oxide) (PEO) segment. The wedge-coil block molecule self-assembles into cylindrical nanofibers in both polar as well as nonpolar solvents. Remarkably, the resulting nanofibers, as solvent polarity change from water to n-hexane, change from highly flexible coil-like to stiff rod-like characteristics. This dynamic switching in the stiffness of the nanofibers in response to solvent polarity is attributed to the structural inversion of cylindrical core from bulky dendritic segments with amorphous nature to crystallizable linear PEO segments.

• Transactions of Materials Processing
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• v.28 no.4
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• pp.212-218
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• 2019

In this study, the first drawing die for the production of coil wedge is redesigned in order to enhance properties such as dimensional accuracy, dimensional uniformity, non-magnetism, and residual stress. The equivalent strain distribution is observed to be asymmetric at certain corners of the product and un-filling of material is also observed at the same location, based on the results of FEM simulation for the current drawing process. Additionally, a relatively huge amount of deformation is concentrated on the surface of the reference product leading to an increase in magnetic component and surface residual stress. After re-designing the cross-section of the first drawing step process conformed to relatively higher amount of reduction ratio, reduction of both surface residual stress and the volume fraction of magnetic component could be achieved for the finally-drawn coil wedge product.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.3
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• pp.80-87
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• 2012

This paper suggests the slot wedge shape for reducing the cogging torque of a direct-drive permanent magnet synchronous generator for a bike. To consider easy coil winding, we applied a structure of open slot for the permanent magnet synchronous generator (PMSG). Because the cogging torque of PWSG with the open slot is very large, we are designed the appropriate specifications of the PMSG by selected the appropriate material of slot wedge and various slot wedge shapes. The prototype model is selected by design theory for reducing cogging torque and maximizing efficiency of PMSG. And the detailed structure design of the model was designed by the loading distribution method. The PMSG models were analyzed by finite element method. Finally, we have suggested appropriate material of slot wedges and its shape which has benefit to further reducing cogging torque and preventing decreasing of the generating power.

• Journal of Power System Engineering
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• v.13 no.6
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• pp.95-101
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• 2009

The generator for gas turbine power generation consists of the rotor which generates magnetic field, the winding coil which is the path for the field current and the wedge and retaining ring which prevents the radial movement of the coil. Relatively severe deformation was observed at the coil end section during the inspection of the generator for peaking-load operation, and the thermal-electricity and the centrifugal force were evaluated by the simple modeling of the windings to find the cause. But the simulation stress was not sufficient to induce the coil plastic deformation. The analysis result seems to be applicable to the base-load generators which runs continuously without shut down up to a year, but there had been more deformation than simulated for the generator which is started up and shut down frequently. The cause of the coil deformation was the restriction of the expansion and shrinkage. The restriction occurs when the winding coil shrinks, and the stress overwhelms the yield stress and cause the plastic deformation. The deformation is accumulated during the start-ups and shut-downs and the thermal growth occurs. The factors which induce the coil restriction during the expansion and shrinkage should be reduced to prevent the unallowable deformation. The resolutions are cutting off the field current earlier during the generator shut-down, modifying the coil end section to remove the stress concentration and making the insulation plate inserted between the coil end section and the retaining ring have the constant thickness.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.1
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• pp.61-66
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• 2010

Pay off reel is the device to release in the form of coil. Every time the device becomes a hassle to exchange, each diameter of two forms has been applied to the coil reel. There is the change of reel diameter of the sleeve portion to be the part of segment geometry. This unit is conducting on 3-dimensional modeling design. The basic strength and deformation of the device could be checked in advance by the basis of 3-d modeling data to perform simulations. The production of each part can be completed and assembled. Conducted for the final product which is tested and measured, all items are satisfied within the limits of targets. Due to the development of this device, the efficiency on operations can be increased and the production time becomes shortened.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1482-1484
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• 1996

To apply Magnetic wedges to the motor, comparing with not applying, showes its performance change of efficiency increse, reduction of temperature rise, harmonics, and magnetic noise. The motor specification and test condition are 37kW-4P-380V-60Hz,squirrel-cage, three phase induction motor with semiclosed type slots. The result of load test to compare with nonmagnetic wedges showed 1.5% increment of efficiency at 100% load and $8.0^{\circ}C$ decrement of temperature rise at stator coil. And for developing the magnetic wedge matrial, its manufacturing process was setting and TG-DTA, optical microscope, SEM, bending strength and permeability were investigated into the material made of through the process.

• Journal of radiological science and technology
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• v.42 no.1
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• pp.39-46
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• 2019

This study conducted a comparative analysis of differences between cartesian trajectory in a linear rectangular coordinate system and MultiVane trajectory in a nonlinear rectangular coordinate system axial T1 and axial T2 images using an American College of Radiology(ACR) phantom. The phantom was placed at the center of the head coil and the top-to-bottom and left-to-right levels were adjusted by using a level. The experiment was performed according to the Phantom Test Guidance provided by the ACR, and sagittal localizer images were obtained. As shown in Figure 2, slices # 1 and # 11 were scanned after placing them at the center of a $45^{\circ}$ wedge shape, and a total of 11 slices were obtained. According to the evaluation results, the image intensity uniformity(IIU) was 93.34% for the cartesian trajectory, and 93.19% for the MultiVane trajectory, both of which fall under the normal range in the axial T1 image. The IIU for the cartesian trajectory was 0.15% higher than that for the MultiVane trajectory. In axial T2, the IIU was 96.44% for the cartesian trajectory, and 95.97% for the MultiVane trajectory, which fall under the normal range. The IIU for the cartesian trajectory was by 0.47% higher than that for the MultiVane trajectory. As a result, the cartesian technique was superior to the MultiVane technique in terms of the high-contrast spatial resolution, image intensity uniformity, and low-contrast object detectability.