• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1371-1375
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• 2005

The paper has analyzed the influence of tire design variable on the tire Force and Moment (F&M) characteristics, especially by the belt angle, the Plysteer Residual Aligning Torque (PRAT) which is considered as one of the causing factors for the vehicle pull. To validate the tire FE model, the tire stiffness and the PRAT which can be derived from the simulation data have been compared with the experimental data of test machine. In addition to PRAT characteristic, the tire stiffness and cornering characteristics due to the belt angle have been investigated. The effects of drum's curvature on the PRAT have been also investigated using the tire FE model and the usefulness of the current drum type F&M test machine can be confirmed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.9
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• pp.903-912
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• 2009

This study is focused on simulation-based dimensional tolerance optimization process (DTOP) to minimize vehicle pulls by reduction of dimensional variation in front suspension system. In previous studies, the effect of tires and wheel alignment sensitivity have mainly been investigated to eliminate vehicle pulls in nominal design condition without allocating optimal tolerance level for selected components, among various factors regarding vehicle pulls such as vehicle design parameters, vehicle weight balance, tires, and environmental factors. Unfortunately, there are wide variations in the real vehicle, and these have impacted actual vehicle pulls, especially wheel alignment effects from suspension geometry variation has not been considered in the previous studies. In the tolerance design of suspension, tolerance variables with the uncertainty such as parts dimensional variation, assembly process, datum position and direction, and assembly tool tolerance has a great influence on the variation of the suspension dimensional performances. This study introduces total vehicle pull prediction model in considering major key factors for vehicle pull sensitivity. The Monte Carlo-based tolerance analysis model using Taguchi robust method is developed to optimize dimensional tolerance parameters, satisfying on the target variation level.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.640-648
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• 2009

Recently the truction of coastal reclaimation work has been extensively implemented in Korea. The Sondo New City is being established on the reclaimed land from the sea, construction companies of metro construction are planing to pull-out the sheet pile for saving the construction cost. In the case of soft marine clay, it is very difficult to pull-out the sheet pile by using the hydraulic hammer difficult. Therefore, the man of the field must be aware of vibration effect to the ground and the structure. For understanding the vibration effect to the ground during subway construction, the model was formulated with 1/25 braced-cut for subway construction. Scott and Iai(1989) proposed the law of the similarity for other experimental conditions. The laboratory model test was conducted under the vibration condition of sheet pile pulling out. The settlement on the ground surface was measured during the shaking table test. The pore water pressure was also monitored in the upper, middle, and lower layers of soil. The field settlement level and the pore water pressure can be predicted by using the results of the laboratory shaking table test.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.3
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• pp.350-357
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• 2006

In this paper, a PSPICE model of piezoelectric transformer and CCFL using an electrical equivalent circuit was presented. The parameters of CCFL for PSPICE were derived by the least square method. The computer simulations were performed and the results are compared on the PSIPCE model of piezoelectric transformer driven by push-pull inverter and CCFL.

• Journal of Korean Society of Forest Science
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• v.89 no.3
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• pp.431-439
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• 2000

In this study, a GIS-application model to determine the optimal route of eco-friendly forest roads and to evaluate the environmental and engineering features of the route was developed. The model consists of five modules for managing spatial and attribute data, determining the optimal route for forest road projection, evaluating environmental and engineering efficiency of forest roads, analyzing characteristics of mountain terrains and report-writing. Using the pull-down menu system, these modules were integrated to be user-friendly for forest field practitioners. Visual Basic 6.0 and Avenue were used as the programming tool and the commercial GIS softwares, ArcView 3.1, Spatial Analyst and 3-D Analyst were used as the basic engine of the model for GIS analysis. In this paper, discussed are the principles for forest road projection and evaluation and structures and application features of the model.

• Journal of Venture Innovation
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• v.3 no.1
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• pp.1-26
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• 2020

The purpose of this study is to explore the factors affecting rural experience by applying the unified push-pull-mooring model. The theoretical model is an unified PPM model that introduces new variables based on PPM. The pull factor of the newly introduced variables were reconstructed based on the Schmitt's Experience model and ServQual model. The hypothesis is set as follows. The push factor will have a negative effect on experience satisfaction and the pull factor(experience attributes, service quality)will have a positive effect on experience satisfaction. Also, mooring factors will have a negative effect on experience satisfaction. The research model of this study was tested by structural equation model based on 314 effective questionnaire data. Service quality had a positive effect on experience satisfaction. Mooring factors have a negative effect on experience satisfaction. Push factor and experience attributes factor were analyzed to have a no significance effect on experience satisfaction. These results theoretically test that the mooring factors also have an important effect on the experience satisfaction in the rural experience. Based on the Schmitt's Experience model and ServQual model introduced as a pull factor, the proposed unified PPM model proved to be a useful analysis framework. In practice, it was able to provide implications on what factors should be strategically and marketingly focused to activate the 6th industry experience.This study examined the impact of start-up education and mentoring on the intentions of business start-up, and verified through empirical analysis whether self-efficacy and resilience were mediated between them. The study surveyed 178 people in their 20s to 50s. The result analysis used the IBM SPSS Statistics 21.0 Statistical Package Program. The analysis performed a regression analysis for factor analysis, correlation analysis, and hypothesis verification. Empirical Research Results. First, it was confirmed that start-up education and mentoring affect on the intentions of business start-up. Second, study shows self-efficacy and resilience has an affect on the intentions of business start-up. Third, start-up education and mentoring affect on self-efficacy and resilience. Fourth, self-efficacy and resilience have been proven to be mediated when entrepreneurship education and mentoring affect on the intentions of business start-up. The results of the research proved that start-up education and mentoring provides and acts as a major role in improving the entrepreneurs' willingness when preparing a start-up. Furthermore, the study also shows the importance of start-up education and mentoring as a proactive variable to promote their will to start-up business. In addition, it was confirmed that the self-efficacy investigated in the preceding study translated into the will to start a business. It was particularly meaningful in that it tested the role of resilience, which was mainly studied in new variables, education and psychology.

• Journal of Biosystems Engineering
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• v.23 no.3
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• pp.219-228
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• 1998

This study was conducted to develop the mathematical model and computer simulation program(TPPMTV98) for predicting the tractive performance of tracked vehicles. It takes into account major design parameters of the vehicle as well as the pressure-sinkage and shearing characteristics of the soil, and the response of the soil to repetitive loading. Structural analysis and numerical iterative method were used for the derivation of mathematical model. The simulatiom model TPPMTV98 can predict the ground pressure distribution and the shear stress under a track, the motion resistance, the tractive effort and the drawbar pull of the vehicles as functions of slip. Predicted tractive performance results obtained by the simulation model were validated by comparing the results firm the Wong's model, the offectiveness of Wong's model validated by many of the experiment. It was found that there is fairy close agreement between the prediction by TPPMTV98 and the results from Wong's model. The computer simulation model TPPMTV98 can be used for the optimization of tracked vehicle design or for the evaluation of vehicle candidates for a given mission and environment.

• Journal of the Korean earth science society
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• v.37 no.1
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• pp.62-77
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• 2016

In the early model of plate tectonics, the plate was depicted as a passive raft floating on the convecting mantle and carried away by the mantle flow. At the same time, ridge push at spreading boundaries and drag force exerted by the mantle on the base of lithosphere were described as the dominant driving forces of plate movements. However, in recent studies of plate tectonics, it is generally accepted that the primary force driving plate motion is slab pull beneath subduction zones rather than other forces driven by mantle convection. The current view asserts that the density contrast between dense oceanic lithosphere and underlying asthenosphere is the substance of slab pull. The greater density of oceanic slab allows it to sink deeper into mantle at trenches by gravitational pull, which provides a dominant driving force for plate motion. Based on this plate tectonics development, this study investigated the contents of plate tectonics in high school Earth Science textbooks and how they have been depicted for the last few decades. Results showed that the early explanation of plate movement driven by mantle convection has been consistently highlighted in almost all high school textbooks since the 5th curriculum, whereas most introductory college textbooks rectified the early theory of plate movement and introduced a newly accepted theory in revised edition. Therefore, we suggest that the latest theory of plate tectonics be included in high school textbooks so that students get updated with recent understanding of it in a timely manner.

• Journal of the Korean Geotechnical Society
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• v.28 no.1
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• pp.5-15
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• 2012

This paper presents the results of an investigation into the pull-out characteristics of screw anchor piles for use in braced excavation and cut-slope. A series of reduced-scale model tests were performed on model screw anchor piles with different geometric characteristics such as screw size and pitch length. The results indicated that the pullout resistance increases with decreasing the pitch length for a given screw size. It was also observed that the pullout capacity of a screw anchor pile increases with the screw size up to a certain size beyond which the increase becomes minimal. The results are presented in such a way that the pullout characteristics of screw piles with different screw geometric characteristics can be identified. Practical implications of the findings are discussed.

• Journal of Adhesion and Interface
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• v.13 no.1
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• pp.9-16
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• 2012

In order to describe external effects on the behavior of the adhesive tape, the semi-rigid body cylinder chain model for adhesive tape has been proposed as follows. Firstly the behavior of the tape is in detail investigated while it's being pulled off from the plate, and subsequently a relevant phenomenological model is designed. Then all the contributors affecting the force to peel out the tape from plate (hereafter, the pull out force) are clearly defined and their sensitivity analyses are made to set up the experimental reference condition, under which the angular dependence of the pull out force is measured in every $10^{\circ}$. The experimental data turn out to be in good agreement with the theoretical ones by our model within the measurement error, and the effects due to other factors are proved to be well explained from the phenomenological viewpoint. From these results, the concept of this study might be expected to be very useful for the test and evaluation of PSA types of adhesive tape.