• Proceedings of the KIEE Conference
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• summer
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• pp.557-559
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• 2004

The study of applying wavelet transform in power cable system fault location has been recognized by many researchers and investigated. For performance of fault location, the fault generated transients can be captured at one end of the cable or both ends. Between two approaches, single-ended approach is less expensive and more reliable as it doesn't need communication link between the ends of the cable. So, we performs the approach based on the one. In this paper, we are going to introduce a new algorithm to discriminate the transient and the reflected signal using wavelet coefficient. For wavelet transform, the stationary wavelet transform(SWT) is applied instead of conventional DWT because SWT has redundancy properties which is more useful in noisy signal processing.

• Journal of the Korean Society for Railway
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• v.19 no.3
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• pp.351-362
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• 2016

The purpose of this study is to investigate service factors and relationships affecting customer satisfaction by measuring indexes of the entire set of high-speed railway station facilities and train services. In this study, we collected data from 202 KTX passengers and analyzed the data using the structural equation model (SEM) method. Through exploratory factor analysis (EFA), we found five major service factors, including parking related service (PRS), station convenient facilities related service (SCS), ticketing services (TIS), service within the train (SWT), and inner environments (INE). As result of a hypothesis test, it was found that PRS does not influence SWT, whereas SCS and TIS positively affect train related service. Also, SWT and INE significantly affect the overall service satisfaction of customers. Thus, our findings provide that station facilities and train service experience are important factors that can enhance customer satisfaction.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.10
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• pp.1390-1393
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• 2006

Data spread over 11 years (1986-1996) pertaining to a synthetic population developed by inter se mating of half-breds of Corriedale and Russian Merino with Nali maintained at CCS Haryana Agricultural University, Hisar were utilized for the estimation of genetic parameters for growth traits. The means for birth weight (BWT), weaning weight (WWT), six month body weight (SWT), yearling weight (YWT), preweaning daily gain (PRW) and post weaning daily gain (POW) were 3.35 kg, 10.79 kg, 13.28 kg, 18.96 kg, 82.6 gm and 27.6 gm, respectively. The effects of year and season of birth and sex of lamb were significant for all the traits under study except the effect of season of birth for WWT, SWT and PRW. No definite trend was observed over the years for the averages of body weight and gain. Lambs born during the spring season performed better for BWT, WWT and PRW while the performance of lambs born during autumn was better for the other traits included in the study. The male lambs were heavier than the females for body weight at all stages and gain in weight. The heritability estimates for WWT and PRW were low; for BWT and SWT were moderate and for YWT and POW were high. Birth weight had high heritability and high genetic correlations with subsequent body weights and gains but due to the presence of a maternal effect on BWT and WWT, a sequential selection procedure is recommended for the improvement of growth rate in sheep.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.1
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• pp.367-376
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• 2014

The purpose of this study was to investigate the effect of either endurance training only or endurance and weight training on muscle morphology and oxidative enzyme activities in human skeletal muscles. Fourteen healthy males were randomly divided into one of two experimental training groups, either swim exercise training (n=7, ST) or combined exercise training (swim and resistance exercise training; n=7, SWT). The change of muscle fiber type was not significantly different between ST and SWT following 6 weeks of exercise training. Mean cross sectional areas as well as the numbers of capillary of different types of muscle fiber were not also significantly different from baseline for both exercise training groups (p>.05) although the tendency of increase were more notable in SWT. All oxidative enzyme activities (i.e., ${\beta}$-hydroxyl acyl dehydrogenase, citrate synthase, and carnitine palmitoyl transferase) were marginally higher in SWT compared to ST even though statistical power did not reach the level of significance. Based on these results, it was concluded that performing of combined (swimming and weight) exercise training could be the better modality for improving muscle morphological changes and oxidative enzyme activities than performing of only single aerobic exercise intervention in young healthy human skeletal muscles.

• Tribology and Lubricants
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• v.28 no.1
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• pp.19-26
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• 2012

Rolling contact fatigue of an urban railway wheel was analysed during its rolling. A FEM analysis was performed using a 3D modelling of rail and wheel, considering the slope of the rail and nonlinear isotropic and kinematic hardening behavior of the rail and the wheel. The maximum von-Mises stress and contact pressure between the rail and wheel were 656.9 MPa and 1111.4 MPa, respectively, under axial load of 85 kN with friction coefficient of 0. The fatigue initiation life prediction relationships by strain-lifetime (${\varepsilon}$-N) and Smith-Watson-Topper method were drawn for the wheel steel as follows: $N_i=7.35{\times}10^6{\times}SWT^{-3.56}$ and $N_i=5.41{\times}10^{-9}{\times}(\frac{{\Delta}{\varepsilon}}{2})^{-5.77}$. The fatigue lifetimes of the wheel due to rolling contact were determined to be infinite by ${\varepsilon}$-N and SWT methods.

• Journal of the Korean Society of Safety
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• v.30 no.3
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• pp.1-6
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• 2015

Self-piercing riveting (SPR) is receiving more recognition as a possible and effective solution for joining automotive body panels and structures, particularly for aluminum parts and dissimilar parts. In this study, static strength and fatigue tests were conducted using coach-peel and cross-tension specimens with Al-5052 plates for evaluation of fatigue strength of the SPR joints. For the static experiment results, the fracture modes are classified into pull-out fracture due to influence of plastic deformation of joining area. During the fatigue tests for the coach-peel and cross-tension specimens with Al-5052, interface failure mode occurred on the top substrate close to the rivet head in the most cycle region. There were relationship between applied load amplitude $P_{amp}$ and life time of cycle N, $P_{amp}=715.5{\times}N^{-0.166}$ and $P_{amp}=1967.3{\times}N^{-0.162}$ were for the coach-peel and cross- tension specimens, respectively. The finite element analysis results for specimens were adopted for the parameters of fatigue lifetime prediction. The relation between SWT fatigue parameter and number of cycles was found to be $SWT=192.8N_f^{-0.44}$.

• The Journal of the Korea Contents Association
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• v.11 no.2
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• pp.113-125
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• 2011

We introduce a media art contents authoring tool called ECAS(Exhibition Contents Authoring System), and methodology employed in its development. ECAS was developed using the graphical user interface to overcome difficulties with existing authoring tools that are text-based. For efficient implementation of graphical user interface, GMF(Graphical Modeling Framework) technique by Eclipse was used. SWT(Standard Widget Toolkit) and JIT(Just-In-Time) were used to improve speed and performance of ECAS. We show convenience and efficiency of ECAS by comparing with existing media art contents authoring tools.

• Journal of Advanced Navigation Technology
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• v.22 no.5
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• pp.359-366
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• 2018

In this paper, the noise is removed by using CTLS aircraft installed FBG sensor inside the aircraft wing. We suggest a normal wavelet transform scheme with motion - invariant characteristics for noise reduction. In the case of installing FBG sensors inside the composite material as in CTLS, large and small empty spaces and parts or sections are generated between the adhesive layers, and a signal splitting problem occurs. FBG sensor is not affected by noise. but eletromagnetic, light source, light detector and signal processing device are influeced by noise because these are eletronic components what affected by eletromagnetic wave. because of this, errors are occured. Experimental results show that the noise can be removed using normal wavelet transform and more accurate data detection is possible.

• Journal of Electrical Engineering and Technology
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• v.13 no.1
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• pp.476-484
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• 2018

The high capacity audio watermarking algorithms are facing a main challenge in satisfying the robustness against attacks especially on de-synchronization attacks. In this paper, a robust and a high capacity algorithm is proposed using segment selection, Stationary Wavelet Transform (SWT) and the Quantization Index Modulation (QIM) techniques along with new synchronization mechanism. The proposed algorithm provides enhanced trade-off between robustness, imperceptibility, and capacity. The achieved watermarking improves the reliability of the available watermarking methods and shows high robustness towards signal processing (manipulating) attacks especially the de-synchronization attacks such as cropping, jittering, and zero inserting attacks. For imperceptibility evaluation, high signal to noise ratio values of above 22 dB has been achieved. Also subjective test with volunteer listeners shows that the proposed method has high imperceptibility with Subjective Difference Grade (SDG) of 4.76. Meanwhile, high rational capacity up to 176.4 bps is also achieved.

• Journal of the Korean Society of Industry Convergence
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• v.20 no.2
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• pp.195-204
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• 2017

Predicting the failure life of automated manufacturing systems can reduce overall downtime, maintenance costs, and total plant operation costs. Therefore, there is a growing interest in fatigue failure mechanisms as the safety or service life assessment of manufacturing systems becomes an important issue. In particular, fretting fatigue is caused by repeated tangential stresses that are generated by friction during small amplitude oscillatory movements or sliding between two surfaces pressed together in intimate contact. Previous studies in fretting fatigue have observed size effects related to contact width such that a critical contact width exists where there is drastic change in the fretting fatigue life. However, most of them are the two-dimensional finite element analyses based on the plane strain assumption. The purpose of this study is to investigate the contact size effects on the three-dimensional finite element model of a finite width of a flat specimen and a cylindrical pad exposed to fretting fatigue. The contact size effects were analyzed by means of the stress and strain averages at the element integration points of three-dimensional finite element model. This study shows that the fretting fatigue life of manufacturing systems can be predicted by three-dimensional finite element analysis based on SWT critical plane model.