• Proceedings of the KSME Conference
• /
• 2007.05a
• /
• pp.172-174
• /
• 2007

A propeller shaft is the device which is used to transmit the power between two shafts in a vehicles, an industrial machinery, etc. The end of spline is worm due to the deflection of the propeller shaft, and a lifetime of it is reduced, because it for industrial machinery has the length of 2,500 mm, the weight of $300\;kg_{f},$ and the sliding distance of $\pm250\;mm.$ Accordingly in this study we analyzed the effect of the gap of spline on the deflection of a propeller shaft carrying out the finite element analysis, in order to determine the proper gap of spline to minimize the deflection of it. We adopt 10-kinds of gap of spline from 0.05 mm to 0.5 mm at interval of 0.05 mm as the design parameter for the finite element analysis and the centrifugal force as the load condition.

• Journal of Magnetics
• /
• v.17 no.4
• /
• pp.275-279
• /
• 2012

The linear actuator has the inherent drawback of air gap variation because its linear motion is usually guided by the springs, which destabilizes the dynamic performance. In order to design the linear actuator to be insensitive to air gap, this paper describes the robust design of the air compressor driving linear actuator using Taguchi method. The orthogonal arrays are constructed with selected control factors and noise factor for minimum experiment. The control factors are thickness of inner magnet, height of upper yoke, thickness of outer magnet and thickness of lower yoke while noise factor is airgap. The finite element analysis using commercial electromagnetic analysis program "MAXWELL" are performed instead of experiment. ANOVA are performed to investigate the effects of design factors. In result, the optimal robust linear actuator which is insensitive to air gap variation is designed.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.10a
• /
• pp.249-252
• /
• 1997

The resolution of analog sensor is determined by its sensitivity and amplitude of noise. This paper presents modeling of inductive gap sensor base on equivalent magnetic circuit and analysis of sensitivity. The model of inductive gap sensor is verified by the experimental results. Then we can simulate static characteristic of inductive gap sensor using this model. Computer simulation show that sensor's sensitivity and linearity are affected by magnetic flux's leakage and fringing, and that they are affected by shape of sensor probe.

• Journal of Electrical Engineering and Technology
• /
• v.10 no.3
• /
• pp.1349-1355
• /
• 2015

It is difficult to calculate the magnetic force of an object of magnetic material in contact with other objects using the existing methods, such as Maxwell stress tensor method, magnetic charge method, or magnetizing current method. These methods are applicable for force computation only when the object is surrounded by air. The virtual air-gap concept has been proposed for calculating the contact force. However, its application is limited to magneto-static system. In this paper, we present the virtual air-gap concept for contact surface force in the eddy-current system. Its validity and usefulness are shown by comparison between numerical and experimental examples.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.1368-1369
• /
• 2008

This paper describes the electric field distribution analysis along a shield form inner vacuum interrupter(VI). The equipotential line and electric field and field vector in a VI are analysed by a finite element method at various shield form. in result, The equipotential line and electric field distribution was affected to VI shield gap. The reason is as it gets distortion of equipotential line done. finally, this paper recognized whether or not affected, and proposed gap with the most suitable shield length and an external insulation.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2010.11a
• /
• pp.160-163
• /
• 2010

We performed three-dimensional CFD analysis to investigate the effect of the nozzle-rotor axial gap of a partial admission supersonic turbine on the stage performance and the flow field. The computations are conducted for five axial gaps using flow analysis program, $FLUENT^{TM}$. The results show that the axial gap between nozzle and rotor give the effect on the mass flow rates of tip leakage and the flow angle at the rotor outlet.

• Proceedings of the KSR Conference
• /
• 2008.11b
• /
• pp.316-320
• /
• 2008

A light rail transit, using a linear induction motor, is generally composed with reaction plates along railroad track and the three phase primary on the vehicle. This linear induction motor is driven to keep clearance between the primary and the secondary of the ground for preventing any contact. Therefore efficiency and power factor is very low. In addition, the reaction plate installed on the ground throughout entire railway is impossible to keep uniform gap and it may cause system deterioration. In this paper, A rotary-type small-scale model of a linear induction motor for various characteristic analysis is designed. Thrust force, normal force and input current of the model by air-gap variation have been analyzed by using a Finite Element Method (FEM). The effects of air-gap variation on system performance have been considered by analysis results.

• Journal of Korean Academy of Nursing Administration
• /
• v.3 no.1
• /
• pp.37-50
• /
• 1997

The purpose of this study was to identify the gap between need-level and demonstration-level in nursing managerial competencies. In addition, the study proposes solutions to narrow this gap. The results of this study are as follows : 1) The mean score for need-level of each item was 4.0, and for demonstration-level, 3.5. This indicates that military hospital head nurses demonstrate a higher level of managerial competencies than the moderate level on all items. But items which were related to resource/ cost/ information managament, staff development management and professionalism management got relatively low ratings in the need-level. 2) The mean score for need-level of each category was 4.14, and for demonstration-level, 3.53. Categories on the individual dimension got a higher rating than categories on the group or organization dimension in both need-level and demonstration level. 3) The gap between need-level and demonstration-level appeared in all items(p<.05) and categories(p<.001). Although the gap was relatively low, it indicates that it is essential to plan a developmemt program for all nursing management competencies for military hospital head nurses. 4) There were significant differences in the gap between need-level and demonstration-level according to specific characteristics of the subjects. The gap did not appear in many categories on the individual dimension where the number of nursing staff was more than 10, a major grade, ICU head nurse or for head nurses having a long career. 5) Need-level and demonstration-level showed a difference according to specific characteristics of the subjects, because need-level and demonstration-level were higher where the number of nursing staff was more than 10, a major grade, and for ICU or Medical ward head nurses. The categories which showed need-level difference and demonstration-level differences according to specific characteristics of the subjects existed almostly completely in the group and organization dimension. Gap-level differences according to the number of hospital bed existed in only two categories. 6) The general causes of the gap were indicated to be 'Knowledge/ skill/ experience deficit', 'Limitation of rules and systems/ Inappropriate organizational environment' for most items, categories, and dimensions. The results of this study indicate that extensive competency developing strategies must be developed, because a gap was found in all items and categories. Specially, there is a need to concentrate attention on competencies in the group and organizational dimension which had a wider gap level. And it is important to take an individual approach according to the cause for each gap. In order to produce effective competency developing strategies, top managers must have sinsights into the importance of nursing staff development and nursing officer's efforts to develop themselves must be achieved. Further multi-dimensional(education, personnel-policy, nursing/ organizational environment) solutions to the gap must be developed and utilized.

• Journal of Korean Society of Transportation
• /
• v.6 no.1
• /
• pp.17-31
• /
• 1988

In this research, the behavior of weaving traffic is studied in terms of lane-changing behavior and gap acceptance characteristics. General trends in lane-changing behavior and gap acceptance characteristics are investigated by analyzing descriptive statistics and the factors affecting weaving behavior are determined by means of the multiple linear regression analysis. The results of analysis show that the behavior of weaving traffic is generally similar to that in a basic freeway section and an on- or of- ramp section. Traffic density and speed appear to be better parameters than traffic volume for explaining the behavior of weaving traffic. For the same purpose, using the traffic conditions of the origin and the destination lanes are found to be more effective than using the average traffic conditions of the freeway. A detailed analysis of the gap acceptance characteristics of late merging vehicles shows that there is no significant difference between the size of gaps accepted by late merging vehicles and that accepted by early merging vehicles.

• Journal of Ocean Engineering and Technology
• /
• v.11 no.4
• /
• pp.249-261
• /
• 1997

A basic study on the lifting lug design has performed through the rational and systematic process. In order to evaluate the proper design-load distribution around lug eye investigation of contact force between lifting lug and shackle pin is performed using non-linear parametric analysis idealized by gap element models. Gap element modeling and nonlinear analysis procedures are illustrated and discussed based on MSC/NASTRAN. Some analysis and design guides are suggested through the consideration of several important effects such as stress distribution pattern, circumferential contact force distribution along the lug eye face, loading share rate between lug main plate and doubler, effect of loading direction, relation between applied force and deflection and size effect of shackle pin radius. Additionally optimum design studies are performed and general trends according to the variation of design parameters are suggested.