• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.2
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• pp.160-176
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• 2017

The interaction of focused wave groups with a vertical wall is investigated based on the second order potential theory. The NewWave theory, which represents the most probable surface elevation under a large crest, is adopted. The analytical solutions of the surface elevation, velocity potential and wave force exerted on the vertical wall are derived, up to the second order. Then, a parametric study is made on the interaction between nonlinear focused wave groups and a vertical wall by considering the effects of angles of incidence, wave steepness, focal positions, water depth, frequency bandwidth and the peak lifting factor. Results show that the wave force on the vertical wall for obliquely-incident wave groups is larger than that for normally-incident waves. The normalized peak crest of wave forces reduces with the increase of wave steepness. With the increase of the distance of focal positions from the vertical wall, the peak crest of surface elevation, although fluctuates, decreases gradually. Both the normalized peak crest and adjacent crest and trough of wave forces become larger for shallower water depth. For focused wave groups reflected by a vertical wall, the frequency bandwidth has little effects on the peak crest of wave elevation or forces, but the adjacent crest and trough become smaller for larger frequency bandwidth. There is no significant change of the peak crest and adjacent trough of surface elevation and wave forces for variation of the peak lifting factor. However, the adjacent crest increases with the increase of the peak lifting factor.

• Journal of Intelligence and Information Systems
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• v.22 no.2
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• pp.1-11
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• 2016

Entani and Tanaka (2007) presented a new approach for obtaining interval evaluations suitable for handling uncertain data. Above all, their approach is characterized by the normalization of interval data and thus the elimination of redundant bounds. Further, interval global weights in AHP are derived by using such normalized interval data. In this paper, we present a heuristic method for finding extreme points of interval data, which basically extends the method by Entani and Tanaka (2007), and also helps to obtain normalized interval data. In the second part of this paper, we show that the solutions to the linear program for interval global weights can be obtained by a simple inspection. In the meantime, the absolute dominance proposed by the authors is extended to pairwise dominance which makes it possible to identify at least more dominated alternatives under the same information.

• The Journal of Korean Obstetrics and Gynecology
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• v.25 no.4
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• pp.56-65
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• 2012

Purpose: This study aims to analyze Heart Rate Variability(HRV) in women with fibroadenoma compared with non-fibroadenoma women. Methods: We studied 82 patients visiting Kang-Nam Kyung-Hee Korean Hospital Medical Examination Center from January, 2010 to November, 2011. The subjects were categorized in two groups, fibroadenoma group(n=16) and non-fibroadenoma group (n=66). We investigated the difference of HRV between two groups. Results: The square root of the mean squared difference of successive NNs (RMSSD) in fibroadenoma group is significantly lower than non-fibroadenoma group. LF/HF ratio in fibroadenoma group is significantly higher than non-fibroadenoma group. There was no significant difference in low frequency(LF) and high frequency (HF). However, normalized LF in fibroadenoma group is significantly higher than non-fibroadenoma group. In addition, normalized HF in fibroadenoma group is significantly lower than non-fibroadenoma group. Conclusions: Fibroadenoma group is related to autonomic nerve imbalances that is assumed by psychological problems.

• Nuclear Engineering and Technology
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• v.47 no.7
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• pp.838-848
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• 2015

One of the most important operations in nuclear power plants is load following, in which an imbalance of axial power distribution induces xenon oscillations. These oscillations must be maintained within acceptable limits otherwise the nuclear power plant could become unstable. Therefore, bounded xenon oscillation is considered to be a constraint for the load following operation. In this paper, the design of a sliding mode control (SMC), which is a robust nonlinear controller, is presented.SMCis ameansto control pressurized water nuclear reactor (PWR) power for the load following operation problem in a way that ensures xenon oscillations are kept bounded within acceptable limits. The proposed controller uses constant axial offset (AO) strategy to ensure xenon oscillations remain bounded. The constant AO is a robust state constraint for the load following problem. The reactor core is simulated based on the two-point nuclear reactor model with a three delayed neutron groups. The stability analysis is given by means of the Lyapunov approach, thus the control system is guaranteed to be stable within a large range. The employed method is easy to implement in practical applications and moreover, the SMC exhibits the desired dynamic properties during the entire output-tracking process independent of perturbations. Simulation results are presented to demonstrate the effectiveness of the proposed controller in terms of performance, robustness, and stability. Results show that the proposed controller for the load following operation is so effective that the xenon oscillations are kept bounded in the given region.

• Korean Journal of Remote Sensing
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• v.30 no.4
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• pp.481-491
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• 2014

Blue-ice area is a glacial ice field in ice sheet, ice shelf and glaciers where snow ablation and sublimation is larger than snowfall. As the blue-ice area has large influences on the meteorite concentration mechanism and ice mass balance, it is required to quantify the concentration of blue-ice. We analyzed spectral reflectance characteristics of blue-ice, snow and cloud by using MODIS images obtained over blue-ice areas in McMurdo Dry Valleys, East Antarctica, from 2007 to 2012. We then developed Normalized Difference Blue-ice Index (NDBI) algorithm which quantifies the concentration of blue-ice. Snow and cloud have a high reflectance in visible and near-infrared (NIR) bands. Reflectance of blue-ice is high in blue band, while that lowers in the NIR band. NDBI is calculated by dividing the difference of reflectance in the blue and NIR bands by the sum of reflectances in the two bands so that NDBI = (Blue-NIR)/(Blue + NIR). NDBI calculated from the MODIS images showed that the blue-ice areas have values ranging from 0.2 to 0.5, depending on the exposure and concentration of blue-ice. It is obviously different from that of snow and cloud that has values less than 0.2 or rocks with negative values. The change of NDBI values in the blue-ice area has higher correlation with snow depth ($R^2=0.699$) than wind speed ($R^2=0.012$) or air temperature ($R^2=0.278$), all measured at a meteorological station installed in McMurdo Dry Valleys. As the snow depth increased, the NDBI value decreased, which suggests that snow depth can be estimated from NDBI values over blue-ice areas. The NDBI algorithm developed in this study will be useful for various polar research fields such as meteorite exploration, analysis of ice mass balance as well as the snow depth estimation.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.49 no.4
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• pp.77-84
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• 2012

Face classification has wide applications in intelligent video surveillance, content retrieval, robot vision, and human-machine interface. Pose and expression changes, and arbitrary illumination are typical problems for face recognition. When the face is captured at a distance, the image quality is often degraded by blurring and noise corruption. This paper investigates the efficacy of multi-classifier decision level fusion for face classification based on the photon-counting linear discriminant analysis with two different cost functions: Euclidean distance and negative normalized correlation. Decision level fusion comprises three stages: cost normalization, cost validation, and fusion rules. First, the costs are normalized into the uniform range and then, candidate costs are selected during validation. Three fusion rules are employed: minimum, average, and majority-voting rules. In the experiments, unfocusing and motion blurs are rendered to simulate the effects of the long distance environments. It will be shown that the decision-level fusion scheme provides better results than the single classifier.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.3
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• pp.335-340
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• 2012

The data used came from two trials undertaken under the same climatic conditions (spring-summer). In both trials pluriparious buffaloes were utilized similar in weight, body condition score, and milk production from the previous year. From the first trial the data used was from the sub-period 23-88 DIM provided by seven animals fed ad libitum with diet A (6.69 MJ/kg DM; 158.30 g/kg of crude protein) with a forage/concentrate ratio of 48/52. From the second trial the data used was from the sub-period 33-90 DIM provided by seven animals fed ad libitum with diet B (6.63 MJ/kg DM; 179.50 g/kg of crude protein) and by seven animals fed ad libitum with diet C (5.99 MJ/kg DM; 155.40 g/kg of crude protein), each of the diets had the same forage/concentrate ratio (53/47). A significant difference was found in milk production between group B and C (13.08 vs. 11.56 kg/d, p<0.05), an intermediate production (12.10 kg/d) was noted in group A. A significant difference was found between fat (76.58 vs. 69.24 g/kg, p<0.05), protein (46.14 vs. 43.16 g/kg, p<0.05) and casein (39.94 vs. 34.98 g/kg, p<0.05) of the milk of group B with respect to group A. The milk of group C gave fat values (71.80 g/kg), protein (45.52 g/kg) and casein (39.06 g/kg) statistically equal to those of group B. The milk of groups B and C, in respect to the milk of group A, gave values of $K_{20}$ (1.77, 1.82 vs. 3.68 min, p<0.05), statistically lower and values of $A_{30}$ (48.28, 47.27 vs. 40.64 mm, p<0.05) statistically higher. Two simple linear regressions were calculated where the independent variable (x) was the daily standardized milk production, the dependent variable (y) or the daily intake of net energy or crude protein. Equation 1) NE (MJ/d) = 74.4049+2.8308${\times}$kg of normalized milk; equation 2) CP (kg/d) = 1.4507+0.1085${\times}$kg of normalized milk, both the equations were significant (p<0.05) with determination coefficients of 0.58 and 0.50 respectively. For a production of normalized milk that varies from 9 to 13 kg, the respective energy-protein concentrations fluctuate from 6.09 to 6.78 MJ/kg DM and from 148.00 to 174.46 g/kg DM.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1381_1382
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• 2009

Nondestructive tests were performed on two 4.16kV motors. Epoxy-mica coupler(80pF) was connected to 4.16 kV motor stator windings. The voltage applied to the stator windings was 2.4 kV, 3.0kV, 3.5kV and 4.16kV, respectively. Digital partial discharge detector(PDD) and turbine generator analyzer(TGA) were used to measure partial discharge(PD) activity. TGA summarizes each plot with two quantities such as the normalized quantity number(NQN) and the peak PD magnitude(Qm). The PD levels in pC were measured with PDD. PD patterns of stator windings were indicated the internal discharge. PD patterns are consistent with the result of measurement using PDD and TGA.

• Communications of the Korean Mathematical Society
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• v.37 no.4
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• pp.1025-1039
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• 2022

For given non-negative real numbers 𝛼_k with ∑^m_k=1 𝛼_k = 1 and normalized analytic functions f_k, k = 1, …, m, defined on the open unit disc, let the functions F and Fn be defined by F(z) := ∑^m_k=1 𝛼_kf_k(z), and F_n(z) := n^-1 ∑^n-1_j=0 e^-2j𝜋i/nF(e^2j𝜋i/nz). This paper studies the functions f_k satisfying the subordination zf'_k(z)/F_n(z) ≺ h(z), where the function h is a convex univalent function with positive real part. We also consider the analogues of the classes of starlike functions with respect to symmetric, conjugate, and symmetric conjugate points. Inclusion and convolution results are proved for these and related classes. Our classes generalize several well-known classes and the connections with the previous works are indicated.

• Proceedings of the KIEE Conference
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• 1999.07f
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• pp.2638-2640
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• 1999

This paper proposes a current-fed type high frequency inverter using a soft switching technology Zero-Voltage-Switching to reduce turn on and off loss at the switching. The analysis of the proposed circuit was described by using normalized parameter and operating characteristics have been evaluated as to switching frequency and parameters. In the future, the proposed circuit is considered to be useful for induction heating applications.