• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.29 no.1
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• pp.165-171
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• 2005

When typhoon approaches, ship normally drops her anchor at proper anchorage for sheltering. If an anchoring ship is under the influence of typhoon, she can keep her position when the external force and counter force is balanced. Where, external force is induced by wind, wave and tidal currents while counter force is induced by holding power of anchor/chain and thrust force of main engine. In this study, authors presented a method to analyze theoretically the limit of external force for the ship to keep her position without being dragged and, to check the validity of method, applied this to the ship which had been anchored in Jinhae Bay when the typhoon MAEMI passed on September 2003.

• Journal of Navigation and Port Research
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• v.29 no.5 s.101
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• pp.357-363
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• 2005

When typhoon approaches, ship normally drops her anchor at proper anchorage for sheltering. If an anchored ship is under the influence of typhoon, she can keep her position when the external force and counter force is balanced. Where, external force is induced by wind, wave and tidal currents while counter force is induced by holding power of anchor/chain and thrust force of main engine. In this study, authors presented a method to analyze theoretically the limit of external force for the ship to keep her position without being dragged and, to check the validity of the method, applied this to the ship which had been anchored in Jinhae Bay when the typhoon MAEMI passed on September 2003.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.80-84
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• 1996

The effects of guide pads on burnishing action and accuracy of machined hole are investigated in drilling with burnishing drill using a speciaaly designed tool experimentally. The cutting forces are balanced at the small forward regions of guide pads. The burnishing action takes place under a high contact pressure between the bore wall and those regions. The over size mechanism of machined hole by the guide pads is discussed.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.279-284
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• 2002

Prestressed concrete(PSC) bridge structures with a number of continuous spans has been segmentally built in many countries. These methods include incremental launching method, movable scaffolding method, full staging method and balanced cantilever method. In these segmentally constructed prestressed concrete bridges, many construction joints exist and these construction joints are weak points in PSC bridges. The prestress force can be introduced prestress force continuously through the construction joints of PSC bridge superstructure using tendon couplers. The main objective of this study is to evaluate the structural behavior and ultimate flexural strength of construction joints in PSC girder bridge members. To this end, a comprehensive experimental program has been set up and a series of full-scale tests have been performed. Ultimate flexural strength of construction joint in PSC members with tendon couplers is decreased by approximately 10% for non-coupled members.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.773-777
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• 1994

This paper is devoted to the development and performance evaluation of a hard bearing type balancing machine for rigid rotors. The pedestals of the balancing machine are designed to be rigid to be rigid enough to enable the balancing to operate far below the fundamental critical speed. The force measuring method is implemented to the balancing machine. The forces due to unbalance are measured through load cell that are attached to the pedestals. A helical coupling is used for transmitting the driving force from an AC servo motor to the rotor to be balanced. The experimental results show that the current hard bearing type balancing machine can indicate the presence of unbalance beyond 1 .mu. m in specific unbalance unit. The limitation of the current balancing machine is due to the coupling that is likely to make inconsistent offset errors everytime the rotor is connected to the machine.

• Journal of the Microelectronics and Packaging Society
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• v.8 no.4
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• pp.35-41
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• 2001

In this paper, several methods to predict the solder joint shape are studied. Although there are various methods to predict the solder joint shape, such as truncated sphere method. force-balanced analytical solution, and energy-based methods like surface evolver developed by Ken Brakke, we calculate solder joint shape of $\mu$BGA by two solder joint shape prediction methods(truncated sphere method and surfaceevolver) and then compare results of each method. The results indicate that two methods can accurately predict the solder Joint shape in an accurate range. After that, we calculate reliability solder joint shape under thermal cycle test by FEA program ANSYS(version 5.62). As a result, it could be found that optimal solder joint shape calculated by solder joint prediction method has best reliability in thermal cycle test.

• Composites Research
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• v.23 no.5
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• pp.8-14
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• 2010

Three types of glass woven fabrics (plain, balanced twill, and unbalanced twill) having various sample sizes and aspect ratios were tested using the bias-extension tests. Real-time deformation images, force, and displacement data were collected. For the bias-extension test, the shear angle of the fabrics from the equation based on the crosshead displacement and fabric size was compared with direct manual measurements of the warp and weft angles as well as the optical measurement software. To determine the shear force, an analytical equation was introduced considering the kinematics of the bias-extension test. The obtained shear behaviors were further compared with the results by the trellis-frame test. The optical measurement methods showed that the mathematical method was reasonable before the shear angle of the fabrics reaches $30^{\circ}$ in the bias-extension tests. Also, the bias-extension test gave consistent behaviors with the trellis-frame test only for isotropic and homogeneous fabrics such as balanced plain and twill weaves.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.2
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• pp.353-364
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• 1998

This paper describes the design processes and evaluation results of a small-sized six-axis force/torque sensor. The new six-axis force/torque sensor including S-type structure has been developed using a parallel plate structure as a basic sensing element. In order tominimize coupling errors, the location of strain gages has been determined based on the finite element analysis and the connections of strain gages have been made such that the bridge circuit with 4 strain gages becomes balanced. Several design modifications result in a similar strain sensitivity for six-axis forces and moments, and the reduced coupling errors of 2.6% FS between each forces and moments. Calibration test results show that the six-axis load cell developed which has light weight of 135g and the maximum capacities of 196 N in forces and 19.6 N.m in moments is estimated to be within 7.1% FS in coupling error.

• Strategy21
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• s.39
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• pp.198-241
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• 2016

Aircraft carriers: are they national platforms to maximize national interest or just simply paper tigers to be little useful for states' development? To some states such as U.S., U.K, and France, aircraft carriers functioned as national assets which is indispensable to their interest. By contrast, Thailand's aircraft carrier was a dead platform which is useless to its national interest and India's ones were little used on the mission field. What is the mechanism leading to this difference? The key is whether states make aircraft carriers connected to overall national evolution when it comes to establishing military strategy and planning a long-term force structure. Put it another way, conditions to acquire them need to be analyzed regarding two variables-national status(prestige and economic power) and threat(mission)-for the future as well as in the present. The former acquired carriers under the condition of making them becoming national platforms which is balanced with their overall development. However, the latter simply bought them without carefully taking account of economic obstacles, e.g., the poverty rate, when it comes to force planning. At the same time, we should not neglect to identify that states of the former cases might have a hard time in maximizing their key interests if they did not have carriers. Accordingly, conditions on carriers' acquisition need to be carefully examined and a typological theory suggested here could shed light on this process. This theory shows that South Korea's status is eligible to have a necessary and sufficient condition to acquire carriers.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.435-442
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• 2004

Tilting train allow the train to pass curve at higher speed without affecting passenger comfort. As the tilting trains run curve track about 30$\%$ higher than non-tilting trains, the centrifugal force and dynamic force will be higher. Therefore it is very important for tilting train to ensure safety against derailment, and to reduce the lateral track forces by applying light-weight design, optimized suspension design and steering mechanism. The 180 km/h Korean Tilting Train(TTX) which is now developing as a part of the Korean National R & D project, was designed and analytically verified to meet these special requirements. This paper describes the analytic study to verify the safety against derailment, especially on the wheel unloading in case of tilting actuation. The severest curve geometry and curving speed was assumed, the tilting control pattern was also assumed as trapezoidal force function applied to tilting bolster and bogie frame. For the comparison, the operation with the speed of tilting train without tilting actuation was numerically simulated and the operation with the balanced speed without tilting actuation was also numerically simulated. Through the numerical simulation of various operating case, we found that derailment quotients, wheel unloading and Q/P was not affected by tilting actuation and that the bogie of TTX was nicely designed to satisfy the safety against the derailment.