• Proceedings of the KSR Conference
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• 2008.11b
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• pp.549-554
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• 2008

The recent trains are almost being operated by the mechanical propulsion force to drive the gear and wheel with the traction motor. However Magnetic Levitation Vehicle is differently operated. Magnetic Levitation Vehicle is applied with Linear Induction Motor(LIM) that has many advantage like to high capability of going up to slope, low noise, easy to control of speed. So domestic and many advanced countries are interested in Magnetic Levitation Vehicle and they have been studying about it continuously. Thus this paper is studied the LIM test method of static states and guess the optimum driving point by characteristic of static states for LIM. The test items are measurement of thrust force by changed air gap, measurement of thrust force and normal force by changed slip frequency etc.

• Journal of the Ergonomics Society of Korea
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• v.28 no.3
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• pp.33-39
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• 2009

Impact force to a body during walking depends on walking speed, walking steps, the condition of the floors and shoes, and weight. The ground reaction force and the foot pressure can be measured instantaneous force easily, but it's difficult to find out the amount of transferring forces to the body. On the other hand, the acceleration has an advantage for analyzing the amount of transferring forces. However, most of studies about impact forces to the ground reaction during exercise have been limited to analyze instantaneous forces. The important thing is to evaluate characters and the amount of the impact force rather than the magnitude. Therefore, this study analyze the impact force using 3 axis acceleration in three dimensions (x; anterior-posterior, y; left-right and z; longitudinal axis) using three axis acceleration. As working speed increased, impact forces increased significantly. Impact forces on x axis and z axis are higher at lower limb than that of upper limb. However, impact force at the knee is higher than that of other parts on y axis regardless of walking speed significantly. In addition, relations of the impact forces as interaction of experiment factors as well as effect of each factor are analyzed.

• Wind and Structures
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• v.18 no.4
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• pp.347-373
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• 2014

Since its development in the early 1980's the force balance technique has become a standard method in the efficient determination of structural loads and responses. Its usefulness lies in the simplicity of the physical model, the relatively short records required from the wind tunnel testing and its versatility in the use of the data for different sets of dynamic properties. Its major advantage has been the ability to provide results in a timely manner, assisting the structural engineer to fine-tune their building at an early stage of the structural development. The analysis of the wind tunnel data has evolved from the simple un-coupled system to sophisticated methods that include the correction for non-linear mode shapes, the handling of complex geometry and the handling of simultaneous measurements on multiple force balances for a building group. This paper will review some of the components in the force balance data analysis both in historical perspective and in its current advancement. The basic formulation of the force balance methodology in both frequency and time domains will be presented. This includes all coupling effects and allows the determination of the resultant quantities such as resultant accelerations, as well as various load effects that generally were not considered in earlier force balance analyses. Using a building model test carried out in the wind tunnel as an example case study, the effects of various simplifications and omissions are discussed.

• Geomechanics and Engineering
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• v.29 no.3
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• pp.229-236
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• 2022

In this study, a model experiment and field experiment was conducted to introduce the optimal tensile force when constructing a non-open cut tunnel according to the ground conditions of sandy soil. CMR (Concrete Modular Roof) method is economical because of the high precision and excellent durability, and corrosion resistance, and the inserted parts can be used as the main structure of a tunnel. In addition the CMR method has a stable advantage in interconnection because the concrete beam is press-fitted compared to the NTR (New Tubular Roof) method, and the need for quality control can be minimized. The ground conditions were corrected by adjusting the relative density of sandy soil during the construction of non-open cut tunnels, and after introducing various tensile forces, the surface settlement according to excavation was measured, and the optimal tensile force was derived. As a result of the experiment, the amount of settlement according to the relative density was found to be minor. Furthermore, analysis of each tensile force based on loose ground conditions resulted in an average decrease of approximately 22% in maximum settlement when the force was increased by 0.8 kN per segment. Considering these results, it is indicated that more than 2.0 kN tensile force per segment is recommended for settlement of the upper ground.

• Structural Engineering and Mechanics
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• v.4 no.5
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• pp.497-511
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• 1996

The equivalent static force procedure and the response spectrum analysis method are widely used for seismic analyses of multi-story buildings. The equivalent static force procedure is one of the most simple but less accurate method in predicting possible seismic response of a structure. The response spectrum analysis method provides more accurate results while it takes much longer computational time. In the response spectrum method, dynamic response of a multi-story building is obtained by combining modal responses through a proper procedure such as SRSS or CQC method. Since all of the analysis results are expressed in absolute values, structural engineers have difficulties to combine them with the results obtained from the static analysis. Design automation is interrupted at this stage because of the difficulty in the decision of the most critical design load. Pseudo-dynamic analysis method proposed in this study provides more accurate seismic analysis results than those of the equivalent static force procedure since the dynamic characteristics of a structure is considered. And the proposed method has an advantage in combination of the analysis results due to gravity loads and seismic loads since the direction of the forces can be considered.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.1
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• pp.103-112
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• 2021

The labor force plays an important role in attracting foreign direct investment (FDI) both in developed and developing countries. In countries where there are appropriate policies for training human resources and maintaining the health of human resources, such countries have a competitive advantage and can attract FDI inflows, besides having a workforce to meet the needs of foreign investors. The purpose of this paper is to analyze the effect of the labor force and several other factors on FDI attraction in Vietnam. The empirical model is employed to perform regression and correlation on the impact of the labor force, real gross domestic product, inflation, index of business freedom, and index of investment freedom on Vietnam's FDI attraction by using a secondary time series data set during the period 1995-2018. The empirical results found that both labor force and inflation have a positive influence on FDI at a 5% significance level; index of business freedom has a positive impact on FDI at a 10% significance level, and real gross domestic product and index of investment freedom have a positive impact on FDI at a 1% significance level. From these results, this study proposes several important policy implications for Vietnam in attracting FDI in the future.

• Journal of the Korea Safety Management & Science
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• v.22 no.1
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• pp.51-59
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• 2020

The importance of innovative capability, the driving force behind innovation as a company's intangible resources, is increasing. In general, companies with high innovation capability are more likely to be successful in innovation, which can be expected to have a positive impact on corporate performance. The innovation capacity of SMEs considered in this study is R&D capability and manufacturing capability. The reason for this is that not only the continuous efforts to strengthen the competitiveness of SMEs are focused on stabilizing manufacturing capability, but also considering the situation in which governmental support for SMEs' R&D capability has been actively developed. This study examines whether R&D capability and manufacturing capability have a significant influence on corporate performance and securing competitive advantage, and analyzes whether competitive advantage acts as a mediator between innovation capability and corporate performance through regression analysis. SPSS 23.0 software was used for the empirical analysis of the data obtained through the survey. The research results are as follows. First, both R&D and manufacturing capabilities of SMEs were found to have a significant positive effect on corporate performance. Second, manufacturing capability had a significant effect on securing competitive advantage of SMEs, but R&D capability was not significant. Third, the competitive advantage of SMEs was found to play a mediating role between manufacturing capability and corporate performance.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.5
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• pp.144-149
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• 2000

The demands for robotic and automatic system are continually increasing in manufacturing fields. There have been many studies to monitor and predict the system, but they have mainly focused upon measuring cutting force, and current of motor spindle, and upon using acoustic sensor, etc. In this study, time series sequence of cutting force was acquired by taking advantage of piezoelectric type tool dynamometer. Radial cutting force was obtained from it and was available for useful observation data. The parameter was estimated using PAA(parameter adaptation algorithm) from observation data. ARMA(auto regressive moving average) model was selected for system model and second order was decided according to parameter estimation. Uncorrelation test was also carried out to verify convergence of parameter.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.3
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• pp.28-35
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• 2013

Micro electrical discharge machining (EDM) as a non-contact machining process is very effective for micromachining with a thin electrode because of its low machining reaction force. The micro-electrode machining device has the advantage of maintaining high precision through the whole processes and uses a feeding wire in the thin electrode tool manufacturing process. This study describes the design and evaluation of a micro-electrode machining device using optical photo-interrupter. The electrode was fabricated by reverse electrical discharge machining. The performance of designed system was evaluated to measure tension force according to feed speed of wire. This system for micro electrode fabrication proves the feasibility in the micro-EDM process of the micro holes and parts for industrial applications.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.13 no.4
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• pp.9-15
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• 2004

A reasonable analysis of cutting force in end milling may give much advantage to improvement of productivity and cutting tool life. In order to analyze cutting force, the cutting dynamics was modelled mathematically by using chip load, cutting geometry, and the relationship between cutting forces and the chip load. The specific cutting constants of the cutting dynamics model were obtained by average cutting forces, tool diameter, cutting speed, feed, axial depth, and radial depth of cut. The model is verified through comparisons of model predicted cutting forces with measured cutting forces obtained from machining experiments. The results showed good agreement and from that we could predict reasonably the cutting forces in end milling.