• Journal of electromagnetic engineering and science
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• 제11권3호
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• pp.174-182
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• 2011

The On-line Electric Vehicle (OLEV) is an electric transport system in which the vehicle's power is transferred wirelessly from power lines underneath the surface of the road. Advantages of the OLEV include reducing battery size and cost to about 20 percent of that of conventional battery-powered electric vehicles, thereby minimizing the vehicle's weight and price, as well as the cost of charging the system. In this paper, we introduce a wireless power transfer mechanism to maximize the electrical performance of the power transfer system. Power transfer capacity, power transfer efficiency, and magnitude of leakage in the electromagnetic field (EMF) are analyzed, and the optimization methodology of the design parameters is discussed.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2001년도 추계학술대회 논문집
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• pp.121-124
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• 2001

On-line prediction model which calculate roll force, roll power and forward slip of continuous hot strip rolling was built based on the results of plane strait rigid-viscoplastic finite element process model. Using the integrated FE process model, a series of finite element simulation was conducted over the process variables, and the influence of various process conditions on non-dimensional parameters was inspected. The prediction accuracy of the proposed on-line model under front and back tension is examined through comparison with predictions from a finite element process model over the various process conditions. In addition, we examined the validity of the on-line prediction model through comparison with roll force of experiment in hot rolling.

• International Journal of Human Ecology
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• 제13권1호
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• pp.105-115
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• 2012

This research investigated the influences of structural characteristics such as fabrics, mechanical properties, and subjective sensory images on the off-line and on-line preferences to women's spring/summer suits fabrics to extract the most effective factor towards preference as well as analyze the preferential off-line and on-line differences to predict the exact texture image on-line. Objective evaluations were done for the measurement of the mechanical properties of fabrics using Kawabata's Evaluation System and subjective evaluations were done with 109 female subjects who value the off-line and on-line sensory image of suit fabrics. For statistical analysis, factor analysis, cluster analysis, t-test, ANOVA, and regression were used. The results were as follows. The preference scores on-line were generally higher than those off-line. For the structural characteristics of fabrics, differences of thickness were observed according to preference clusters, and the preference increased as thickness was lowered off-line and on-line. For mechanical properties, WC influenced off-line and on-line preferences. Fabrics with low compression energy were preferred; however, the effect of SMD was observed off-line only. In subjective sensory images, the 'smoothness' image influenced off-line and on-line preferences the most. All sensory images influenced the off-line preferences; however, the effects of 'flexibility' and 'weight' were not shown on-line.

• International Journal of Automotive Technology
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• 제8권3호
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• pp.375-382
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• 2007

The multi-driver off-road vehicle drive-line consists of many components, with close connections among them. In order to design and analyze the drive-line efficiently, a modular methodology should be taken. The aim of a modular approach to the modeling of complex systems is to support behavior analysis and simulation in an iterative and thus complex engineering process, by using encapsulated submodels of components and of their interfaces. Multi-driver off-road vehicles are comparatively complicated. The driving-line is an important core part to the vehicle, it has a significant contribution to the performance. Multi-driver off-road vehicles have complex driving-lines, so performance is heavily dependent on the driving-line. A typical off-road vehicle's driving-line system consists of a torque converter, transmission, transfer case and driving-axles, which transfers the power generated by the engine and distributes it effectively to the driving wheels according to the road condition. According to its main function, this paper proposes a modularized approach for design and evaluation of the vehicle's driving-line. It can be used to effectively estimate the performance of the driving-line during the concept design stage. Through an appropriate analysis and assessment method, an optimal design can be reached. This method has been applied to practical vehicle design, it can improve the design efficiency and is convenient to assess and validate the performance of a vehicle, especially of multi-driver off-road vehicles.

• 소성∙가공
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• 제28권2호
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• pp.83-88
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• 2019

This paper introduces a new concept - on-line FE model, as applied to metal rolling. The new technology allows for completion of process simulation within a tiny fraction of a second without loss of high-level prediction accuracy inherent to FEM. The three steps of an on-line FE model design namely, process metamorphosis, mesh design, and process variable design, are described in detail. The procedure is demonstrated step by step through designing actual on-line models for the prediction of the dog-bone profile in edge rolling. The validity and prediction accuracy of the on-line FE models are analyzed and discussed.

• 한국생산제조학회지
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• 제20권4호
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• pp.407-411
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• 2011

The technology of line heating has evolved in various methods. Among them, fossil fuels like ethylene gas and LPG(Liquid Petroleum Gas) are widely used due to their simple utility. In the meantime, the technology implementing high frequency for line heating has also been developed continually, but its manufacturing technology or application includes lots of problems by now. One of the main characteristics of line heating using conventional technolob'Y is the quenching effect followed by heating process. On the other hand, hydrox gas which is mixed by hydrogen and oxygen is a prominent candidate for an application without above shortcomings. Especially, it is found that line heating using hydrox gas is tremendously effective taking low cost as well as low noise. In this paper, a small cell with high efficiency which can minimize installing space is developed to deal with the problem installing in narrow place. Experiments to prove the validation, efficiency and effectiveness is carried out by characterizing in the line heating of steel. It is found that the energy saving of using hydrox gas for line heating is significant and that the deviation performance is reduced by 78~89%. Furthermore, the noise is also reduced as amount of 18.3% though the heating time is not too different.

• 한국기술혁신학회:학술대회논문집
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• 한국기술혁신학회 2001년도 춘계학술대회:발표자료
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• pp.9-21
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• 2001

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
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• pp.244-247
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• 1995

A technique is presented for evaluating spinal deformity of a human back by extracting a spinal line based on 3-D topograpic reconstruction of the back from its moire image. A given moire image is differentiatedby DOG filter to extract moire stripes. The stripes are then assigned labels and the labels are interpolated by the Lagrange polynomial to yield the undulation of the back which gives a relative 3-D shape of the back. A valley is searched on the undulation near the middle part of the back and the valley line is finally extracted as an approximated spinal line. The mean differenceand the variance between the spinal line and the middle line are calculated and reported. Experiment is performed employing real moire images ofjunior-high school students' backs and some of the results are shown with discussion.

• Journal of Electrical Engineering and Technology
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• 제9권5호
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• pp.1677-1685
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• 2014

Major problem in the high voltage power transmission line is the flashover due to polluted ceramic insulators which leads to failure of equipments, catastrophic fires and power outages. This paper deals with the development of a better diagnostic tool to predict the flashover and pollution severity of power transmission line insulators based on the wavelet transform and fuzzy c-means clustering approach. In this work, laboratory experiments were carried out on power transmission line porcelain insulators under AC voltages at different pollution conditions and corresponding leakage current patterns were measured. Discrete wavelet transform technique is employed to extract important features of leakage current signals. Variation of leakage current magnitude and distortion ratio at different pollution levels were analyzed. Fuzzy c-means algorithm is used to cluster the extracted features of the leakage current data. Test results clearly show that the flashover and pollution severity of power transmission line insulators can be effectively realized through fuzzy clustering technique and it will be useful to carry out preventive maintenance work.

• Nuclear Engineering and Technology
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• 제54권8호
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• pp.2989-2998
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• 2022

Line contact structures, such as the contact between graphite brick and graphite tenon, widely exist in high-temperature gas-cooled reactors. Due to the stress concentration effect, the line contact area is one of the dangerous positions prone to failure in the nuclear reactor core. In this paper, the failure mechanism of line contact structures composed of IG11 nuclear graphite column and brick were investigated by means of experiment and finite element simulation. It was found that the failure process mainly includes three stages: firstly, the damage accumulation in nuclear graphite material led to the characteristic yielding of the line contact structure, but no macroscopic failure can be observed at this stage; secondly, the stresses near the contact area met Mohr failure criterion, and a crack initiated and propagated laterally in the contact zone, that is, local macroscopic failure occurred at this stage; finally, a second crack initiated in the contact area and developed in to a Y-shape, resulting in the final failure of the structure. This study lays a foundation for the structural design and safety assessment of high-temperature gas-cooled reactors.