• Journal of applied mathematics & informatics
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• v.26 no.3_4
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• pp.689-706
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• 2008

In this paper, a fifth order numerical method is presented for solving singularly perturbed two point boundary value problems with a boundary layer at one end point. The two point boundary value problem is transformed into general first order ordinary differential equation system. A discrete approximation of a fifth order compact difference scheme is presented for the first order system. An asymptotically equivalent first order equation of the original singularly perturbed two point boundary value problem is obtained from the theory of singular perturbations. It is used in the fifth order compact difference scheme to get a two term recurrence relation and is solved. Several linear and non-linear singular perturbation problems have been solved and the numerical results are presented to support the theory. It is observed that the present method approximates the exact solution very well.

• ETRI Journal
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• v.32 no.1
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• pp.1-10
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• 2010

In this paper, we present a fast Fourier transform (FFT) processor with four parallel data paths for multiband orthogonal frequency-division multiplexing ultra-wideband systems. The proposed 128-point FFT processor employs both a modified radix-$2^4$ algorithm and a radix-$2^3$ algorithm to significantly reduce the numbers of complex constant multipliers and complex booth multipliers. It also employs substructure-sharing multiplication units instead of constant multipliers to efficiently conduct multiplication operations with only addition and shift operations. The proposed FFT processor is implemented and tested using 0.18 ${\mu}m$ CMOS technology with a supply voltage of 1.8 V. The hardware- efficient 128-point FFT processor with four data streams can support a data processing rate of up to 1 Gsample/s while consuming 112 mW. The implementation results show that the proposed 128-point mixed-radix FFT architecture significantly reduces the hardware cost and power consumption in comparison to existing 128-point FFT architectures.

• Structural Engineering and Mechanics
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• v.70 no.6
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• pp.711-722
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• 2019

Considering stress singularities at point support locations, buckling solutions for plates with arbitrary number of point supports are hard to obtain. Thus, new Hp-Cloud shape functions with Kronecker delta property (HPCK) were developed in the present paper to examine elastic buckling of point-supported thin plates in various shapes. Having the Kronecker delta property, this specific Hp-Cloud shape functions were constructed through selecting particular quantities for influence radii of nodal points as well as proposing appropriate enrichment functions. Since the given quantities for influence radii of nodal points could bring about poor quality of interpolation for plates with sharp corners, the radii were increased and the method of Lagrange multiplier was used for the purpose of applying boundary conditions. To demonstrate the capability of the new Hp-Cloud shape functions in the domain of analyzing plates in different geometry shapes, various test cases were correspondingly investigated and the obtained findings were compared with those available in the related literature. Such results concerning these new Hp-Cloud shape functions revealed a significant consistency with those reported by other researchers.

• Nonlinear Functional Analysis and Applications
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• v.28 no.1
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• pp.251-263
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• 2023

In the setting of extended quasi b-metric spaces, we introduce a new concept called "extended A-contraction". We then use our concept to prove a common fixed point result for a pair of self mappings under a set of conditions. Also, we provide the concepts of extended B-contraction and extended R-contraction. We then establish a common fixed point under these new contractions. Our results generalize many existing result of fixed point in metric spaces. Furthermore, we give an example to illustrate and support our result.

• Journal of Advanced Marine Engineering and Technology
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• v.5 no.1
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• pp.20-27
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• 1981

The alignment of propulsion shaft systems by the fair curve method has been developed over the past twenty years and in recent years its basic problems have been almost solved. At the present time, studies on introducing actual conditions are being undertaken. In a fair curve alignment, its aim is to achieve a stable shaft system which will be relatively insensitive to misalignment or the influence of external factors such as thermal variations due to the sunshine, speed change, etc. The key point of fair curve alignment is the calculations of reactions in the straight support and reaction influence numbers. The present authors have developed those calculating method by the matrix method of the three-moment theorem. The fair curve alignment is based on the analysis of propulsion shaft system which is assumed as a continous beam on multiple support points. The propeller shaft is divided into several elements. For each element, the nodal point equation is derived by the three-moment theorem. Reaction of supporting points of straight shaft and reaction influence numbers are calculated by the matrix calculation of each nodal point equation. It has been found that results of calculation for the model shaft agree well with those of experiment which had been measured by the strain gauge method. Results of calculation for the actual propulsion shafting of the steam turbine had been compared also with those of Det norske Vertas.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.4B
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• pp.224-231
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• 2008

EPONs are a low cost, high speed solution to the bottleneck problem of broadband access networks. To support point-to-point and shared LAN emulation, EPONs use the multi-point control protocol (MPCP), which uses logical link identification (LLID) for frame tagging and filtering between the OLT and ONUs. In this paper, ONU-based multicast or multiple shared LAN emulation is used for IPTV channel package delivery services. Using ONU-based VLAN services, EPONs can support separate and secure connections between providers and subscribers in a simple manner. Also, IPTV channel packages can be delivered through EPONs by implementing ONU-based VLAN and IGMP snooping mechanisms. By showing fast channel zapping time of proposed architecture, I show that EPONs is suitable for IPTV channel package delivery service.

• Journal of East-West Nursing Research
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• v.11 no.1
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• pp.25-32
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• 2005

Purpose: This study was aimed to identify the factors that related the dietary behavior in coronary artery disease patients and to made the data for nursing which is thought to improve the dietary behavior. Method: The study population was the coronary artery disease patients who were treated at outpatient base. The study method was the dietary behavior, diet self-efficacy, perceived-healthy behavior, social support measurement & characteristics. All of the above tool was validated for its composition propriety and confidence. The statistical analysis was done by SPSS PC 11.0 program. and frequency, percentage, mean, standard deviation, Pearson's correlation was used for analysis. Results: The score of dietary behavior in the coronary artery disease patients was 4.57 point. The score of perceived-benefits was the highest among the association factor(point) and the score of perceived-barriers(m=2.78), diet self-efficacy(m=5.12), social support(m=4.86 point), exercise and chest pain. Conclusion: The development of the program for the efficient dietary education that prevents the progression of the coronary artery disease is needed.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.6
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• pp.497-505
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• 2016

Operating wind turbine generators at maximum power point requires maximum power point tracking (MPPT) control methods. However, conventional methods cannot track the appropriate maximum power point in situations involving wind turbine systems based on a series operation strategy. These systems comprise one or more local maximum power points, and conventional methods can detect only one local maximum power point closed by a current operation point. This study proposes an advanced MPPT method for the series operation strategy of a small, grid-connected wind turbine system. In determining the appropriate maximum point, operations at certain local maximum power points are analyzed. The results show one appropriate point, which is tracked by the proposed MPPT method. The effectiveness of the proposed method is verified by the experimental results.

• Korean Journal of Social Welfare Studies
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• v.45 no.2
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• pp.99-122
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• 2014

The purpose of this study is to examine how providing care to grandchildren and the continuity of care affects the grandparents' perception on old-age support. Specifically, in this study, providing care is divided into three continuous types: did not provide care, provided care at one point in time and provided care at two points in time. This is done to investigate how the duration of providing care influences the perception on old-age support. The results show that grandparents providing care to their grandchildren prefer to reside with their own children in the future more often than those who do not provide care to their grandchildren. Furthermore, grandparents providing care to their grandchildren during two-time points and grandparents providing care during one-time point prefer to reside with their adult children in the future more than grandparents providing care not once during two-time points. Interestingly, grandparents who provide care to grandchildren during two-time points prefer to reside with their children in the future more frequently than grandparents providing care during just one-time point. These results suggest it is likely that grandparents recognize providing care to their grandchildren as an insurance in care and support for themselves in the future. Additionally, these results suggest that the family plays an efficient and flexible role to meet needs of family members through a reciprocal relationship in Korean society where the public sector is weak. These findings have suggested theoretical implications.

• Journal of the Korean housing association
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• v.20 no.2
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• pp.11-18
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• 2009

After 2004, as the community mixed-support facility in Japan was admitted as a private business of public facilities based on the Special Law for Urban Regeneration, the community mixed-support facilities in Japan are developed into various types with the view of the urban regeneration and urban renewal, more different point of view, and a tendency of establishment of the community facility has been considerably changed for the past twenty years. The reasons of the change are the social demand for the reformation of facility and the modification of subsidy constitution according to the establishment of equal facility. Some examples of that are the construction of lifelong education community and the change into a equivalent society between male and female and the adjusting to the aging and the welfare society and the social situation of more consumption recently, and in order to emerge from former building system, new facilities related to the contents are being expanded. The complex of the community mixed-support facility has an advantage in that it supplies the services for the complex of the community mixed-support facility, constitutes the communal character and the sense of solidarity among residents and can lead the development of region through the exchange of regional information. Through the Japanese community mixed-support facility which has many cases of it, this study would recognize the suggestion, the feature of it and examine the complex types.