• Journal of Power Electronics
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• v.17 no.5
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• pp.1338-1348
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• 2017

In this study, a modified ripple correlation control (RCC) maximum-power point-tracking (MPPT) algorithm is proposed for a single-stage single-phase voltage source inverter (VSI) on a grid-connected photovoltaic system (GCPVS). Unlike classic RCC methods, the proposed algorithm does not require high-pass and low-pass filters or the increment of the AC component filter function in the voltage control loop. A simple arithmetic mean function is used to calculate the average value of the photovoltaic (PV) voltage, PV power, and PV voltage ripples for the MPPT of the RCC method. Furthermore, a high-accuracy and high-precision MPPT is achieved. The performance of the proposed algorithm for the single-stage single-phase VSI GCPVS is investigated through simulation and experimental results.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.11
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• pp.5674-5691
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• 2016

Fast IDentity Online(FIDO) supports biometric authentications in an online environment without transmitting biometric templates over the network. For a given FIDO client, the "Fuzzy Vault" securely stores biometric templates, houses additional biometric templates, and unlocks private keys via biometrics. The Fuzzy Vault has been extensively researched and some vulnerabilities have been discovered, such as brute force, correlation, and key inversions attacks. In this paper, we propose a simple fingerprint Fuzzy Vault for FIDO clients. By using the FIDO feature, a simple minutiae alignment, and point-to-point matching, our Fuzzy Vault provides a secure algorithm to combat a variety of attacks, such as brute force, correlation, and key inversions. Using a case study, we verified our Fuzzy Vault by using a publicly available fingerprint database. The results of our experiments show that the Genuine Acceptance Rate and the False Acceptance Rate range from 48.89% to 80% and from 0.02% to 0%, respectively. In addition, our Fuzzy Vault, compared to existing similar technologies, needed fewer attempts.

• Magazine of the Korean Society of Agricultural Engineers
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• v.41 no.6
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• pp.44-53
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• 1999

The statistical characteristics of the factors related to the daily rainfall prediction model are analyzed . Records of daily precipitation, mean air temperature, relative humidity , dew-point temperature and air pressure from 1973∼1998 at 8 meteorological sttions in south-western part of Korea were used. 1. Serial correlatino of daily precipitaiton was significant with the lag less than 1 day. But , that of other variables were large enough until 10 day lag. 2. Crosscorrelation of air temperature, relative humidity , dew-point temperature showed similar distribution wiht the basin contrours and the others were different. 3. There were significant correlation between the meteorological variables and precipitation preceded more than 2 days. 4. Daily preciption of each station were treated as a truncated continuous random variable and the annual periodic components, mean and standard deviation were estimated for each day. 5. All of the results could be considered to select the input variables of regression model or neural network model for the prediction of daily precipitation and to construct the stochastic model of daily precipitation.

• Journal of the Korean Society of Safety
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• v.26 no.5
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• pp.27-32
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• 2011

Recently new technological development needs the advances in the fields of new materials. The most advanced design is not useful if new material's performance is not realized adequately for bearing the service loads and conditions. FGMs suggests the reasonable solution for the those requirements because of its wide range microstructure and the continuous constitutions. It's especially good for the heat-resisting components, piezoelectricity and aerocraft fields. However the fabrication and its experimental estimation methods have not been established because of its various freedom of material's properties. Therefore it is necessary to develope the fabrication method and estimation of strength and deformation. The experiments are conducted under a four point flexural test. According to results, this study shows that FGMs is well fabricated and the deformation and strain fields are expressed very well by digital image correlation method.

• Anatomy and Cell Biology
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• v.56 no.4
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• pp.415-420
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• 2023

The tibial nerve is a branch of the sciatic nerve, which innervates the legs and feet. Anatomical variations of this nerve at the ankle are commonly found. The variation of the tibial nerve in its branching point and cross-sectional area (CSA) at the ankle is commonly related to clinical condition such as foot neuropathy. Knowledge of these variations can support the clinician in making appropriate clinical decisions. This review aims at providing knowledge on the anatomical variations of tibial nerve at ankle, as well as its clinical correlation. This review outlined the variation of the terminal branching point and CSA of the tibial nerve at the ankle in cadaveric and clinical studies.

• Journal of Electrical Engineering and Technology
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• v.8 no.6
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• pp.1605-1614
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• 2013

This paper presents a probabilistic methodology for small signal stability analysis of power system with correlated wind sources. The approach considers not only the stochastic characteristics of wind speeds which are treated as random variables with Weibull distributions, while also the wind speed spatial correlations which are characterized by a correlation matrix. The approach based on the 2m+1 point estimate method and Cornish Fisher expansion, the orthogonal transformation technique is used to deal with the correlation of wind farms. A case study is carried out on IEEE New England system and the probabilistic indexes for eigenvalue analysis are computed from the statistical processing of the obtained results. The accuracy and efficiency of the proposed method are confirmed by comparing with the results of Monte Carlo simulation. The numerical results indicate that the proposed method can actually capture the probabilistic characteristics of mode properties of the power systems with correlated wind sources and the consideration of spatial correlation has influence on the probability of system small signal stability.

• Journal of Korean Academy of Nursing
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• v.45 no.2
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• pp.262-270
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• 2015

Purpose: This study was conducted in order to examine the effects of death anxiety and meaning of life on somatization of grandparents raising grandchildren. Methods: A convenience sample of 92 elderly grandparents raising grandchildren was recruited. The study instrument for death anxiety was the 5-point 15 items scale designed by Templer and translated by Ko, Choi, & Lee and for meaning of life, the 7-point 10-items scale by Steger, Frazier, Oishi & Kaler and translated by Won, Kim & Kwon. For somatization, the 5-point 12 items scale designed by Derogatis and translated by Kim, Kim & Won was used. Collected data were analyzed with descriptive statistics, independent t-test, one-way ANOVA, Pearson Correlation and regression using the SPSS 21.0 program. Results: Average scores were 3.55 for death anxiety, 3.43 for meaning of life, and 2.74 for somatization. Death anxiety had the highest positive correlation with somatization. Meaning of life was negatively correlated with death anxiety and somatization. Death anxiety and health status were shown to influence somatization but meaning of life was not shown to influence somatization. Conclusion: The research results indicate that death anxiety and health status influence somatization in grandparents raising grandchildren. These results also provide basic information on the importance of nursing interventions in which the variables influencing somatization in grandparents raising grandchildren are considered.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.12
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• pp.12-20
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• 1993

In a conventional adaptive echo canceller, an ADF(Adaptive Digital Filter) with TDL(Tapped-Delay Line) structure modelling the echo path uses the LMS(Least Mean Square) algorithm to compute the coefficients, and NET detector using energy comparison method prevents the ADF to update the coefficients during the periods of the NET signal presence. The convergence speed of the LMS algorithm depends on the eigenvalue spread ratio of the reference signal and NET detector using the energy comparison method yields poor detection performance if the magnitude of the NET signal is small. This paper presents a new adaptive echo canceller which uses the pre-whitening filter to improve the convergence speed of the LMS algorithm. The pre-whitening filter is realized by using a low-order lattice predictor. Also, a new NET signal detection algorithm is presented, where the start point of the NET signal is detected by computing the cross-correlation coefficient between the primary input and the ADF output while the end point is detected by using the energy comparison method. The simulation results show that the convergence speed of the proposed adaptive echo canceller is faster than that of the conventional echo canceller and the cross-correlation coefficient yields more accurate detection of the start point of the NET signal.

• The Research Journal of the Costume Culture
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• v.5 no.4
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• pp.130-158
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• 1997

This study outputs calculation of regression of each items for production of torso basic pattern according to 6 body types as the result of another study and intends to present drawing method of torso model by short measure method modified and supplied and supplied by experiments of wearing clothing. SAS(Statistical Analysis System) is used for figures management and methods for analysis used are Frequency Analysis, Means Analysis, Regression Analysis, Correlation Analysis, etc. Results are as follows. 1. Correlation analysis is used to output the size necessary for torso prototype drawing by sort measure method and waist front length, back length, crotch length, shoulder point-cerricale-shoulder point, bust circumference, waist circumference, weight, etc, are set up as representative items calculation of regression of each type is suggested. 2. In the result of experiment of the first wearing clothing intended for 5 in each type and the whole 30, to develop torso prototype drawing method by short measure method, as we find some problems of the shape and propriety of neck root circumference line, the position of shoulder point, pulling or hold armpit parts, waist circumference line, the degree of dissatisfaction is high, so the second experiment of wearing clothing is propriety of each part is improved, all items except the length and quantity of shoulder dart, waist in back bodice, clearance quantity of hip circumference, and the place of shoulder line in side bodice. So, it was modifed and supplied and then the third torso prototyped drawing method by shout measure method was suggested. The third prototype drawing method was suggested, by modifying and supplying.

• Journal of Korean Society on Water Environment
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• v.24 no.2
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• pp.169-173
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• 2008

A field monitoring was conducted in order to find out the discharge characteristics of non-point source pollutants in the agricultural area. Event Mean Concentration (EMC) of TSS, $BOD_5$, $COD_{Mn}$, TP, TN was calculated based on the monitoring data of 10 rainfall events at agricultural watersheds. A significant relationship was observed from the correlation between EMCs and rainfall characteristics. The result shows that EMC ranges of 95% confidence intervals were 50.5~203 mg/L for TSS, 0.8~14.2 mg/L for $BOD_5$, 4.2~20.7 mg/L for $COD_{Mn}$, 2.4~4.5 mg/L for TN and 0.2~0.5 mg/L for TP, respectively. The correlation coefficients between TSS and TP and between $BOD_5$ and $COD_{Mn}$ were found to be 0.912 and 0.961. But TN was lower correlated with other EMC factors. It was also found that rainfall characteristics was not correlated with EMCs.