• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.453-458
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• 2001

This paper presents the procedure to find the hysteresis loop of RC member using a modified strut-and-tie model. The forces and displacements at critical points, that are initial yielding point, target displacement point, unloading elastic limit, and reloading point after pinching, are investigated with the strut-and-tie models. Using bond-slip relationship, the elastic behavior of tie element is determined. The plastic flow behavior after flexural yielding is expressed by changing the location of longitudinal strut. Determination of pinching effect completes the initial hysteresis loop, assuming that the behavior of the opposite direction is symmetrical form.

• The Pure and Applied Mathematics
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• v.30 no.2
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• pp.169-190
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• 2023

In this paper, we introduce an extension of rectangular metric spaces called controlled rectangular metric spaces, by changing the rectangular inequality in the definition of a metric space. We also establish some fixed point theorems for self-mappings defined on such spaces. Our main results extends and improves many results existing in the literature. Moreover, an illustrative example is presented to support the obtained results.

• Journal of Acupuncture Research
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• v.24 no.4
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• pp.69-80
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• 2007

Objective : This study was designed to evaluate the effect of combined Silver Spike Point Therapy and Electroacupuncture on symptoms with Peripheral Facial Paralysis. Methods: We investigated 112 cases of patients with Peripheral Facial Paralysis. The patients were divided into two groups. Group A and B were both treated with basic oriental medicine treatment including Electroacupunctre and Group B was treated with Silver Spike Point Therapy additionaly. We evaluated the tratment effect of each group by using Gross Grading System of House-Brackmann, Yanagihara's Unweighed Grading System before treatment, after 2weeks and 4weeks treatment and Changing Point -period from onset of Peripheral Facial Paralysis to the day which the change begins to be seen at the face-. Results: 1. In Changing point, two groups showed significant differences. 2. As a results of evaluation by using Gross Grading system of House-Brackmann, Yanagihara's Unweighed Grading System, treatment scores showed significant difference over time in each group. 3. After 4weeks treatment, Group B showed significant difference on Gross Grading system of House-Brackmann, Yanagihara's Unweighed Grading System compared with Group A. 4. After 2weeks and 4weeks treatment, the Improvement Indexes of Group B were higher than those of Group A and statistically significant. And after 2weeks and 4weeks treatment, Ratio of Group B on mean of Improvement Index was 1.47 times and 1.34 times as large as those of Group A. Conclusions : Combined Silver Spike Point Therapy on Peripheral Facial Paralysis was more efficacious than the only use of basic oriental treatment including Electroacupuncture.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.2
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• pp.99-106
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• 2006

In this paper, the new method that estimates a sensing ability of smart sensor will be proposed. A study is estimation method that evaluates sensing ability about smart sensor respectively. According to acceleration(g) and displacement changing, we estimated sensing ability of smart sensor using SAI(Sensing Ability Index) method respectively. Smart sensors was made fer experiment. The types of smart sensor are two types(hard and soft smart sensor). Smart sensors developed for recognition of material. Experiment and analysis are executed for estimate the SAI method. In develop a smart sensor, the SAI method will be useful for finding optical design condition of smart sensor that can sense a material. And then dynamic characteristics of smart sensors(frequency changing, acceleration changing, critical point, etc.) are evaluated respectively through new method(SAI) that use the power spectrum density. Dynamic characteristic of sensor is evaluated with SAI method relatively. We can use the SAI for finding critical point of smart sensor, too.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.10
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• pp.1865-1874
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• 2011

This paper proposes a novel maximum power point tracking(MPPT) using a new fuzzy control(NFC) algorithm for robust in insolation variation. Maximum power point(MPP) of solar cell has to achieve for improving output efficiency because it is changed with insolation and temperature. Conventional MPPT controller such as constant voltage(CV), perturbation and observation(PO) and incremental conductance(IC) are researched. But these controller have the problem that is failure to MPP with environment changing. The proposed NFC controller is based the fuzzy control algorithm and able to robust control with environment changing. Also the proposed controller of PV system is modeled by PSIM and the response characteristics according to the parameter variation is compared and analyzed. The validity of this controller is proved through response results.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.77-78
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• 2010

As the maximum power operating point(MPOP) of photovoltaic(PV) power systems alters with changing atmospheric conditions, the efficiency of maximum power point tracking(MPPT) is important in PV power systems. Moreover, grid-connected PV system occurs some problems such as voltage inequality and harmonics. Therefore, this paper presents the results of a grid-connected PV system modeling by PSIM simulator and investigates the influence on the grid-connected PV system from aspect of power quality, i.e. voltage drop. This paper includes four MPPT algorithms; Perturbation & Observation(P&O), Improved P&O, Increment Conductance(Incond), Hysterisis simulated with irradiation changing.

• Kyungpook Mathematical Journal
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• v.59 no.1
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• pp.65-71
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• 2019

This paper is concerned with the existence of positive solutions of the nonlinear Neumann boundary value problems $$\{u^{{\prime}{\prime}}+a(t)u={\lambda}b(t)f(u),\;t{\in}(0,1),\\u^{\prime}(0)=u^{\prime}(1)=0$$, where $a,b{\in}C[0,1]$ with $a(t)>0,\;b(t){\geq}0$ and the Green's function of the linear problem $$\{u^{{\prime}{\prime}}+a(t)u=0,\;t{\in}(0,1),\\u^{\prime}(0)=u^{\prime}(1)=0$$ may change its sign on $[0,1]{\times}[0,1]$. Our analysis relies on the Leray-Schauder fixed point theorem.

• Structural Engineering and Mechanics
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• v.5 no.6
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• pp.691-703
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• 1997

This paper investigates the optimal locations of internal point supports in a symmetric crossply laminated rectangular plate for maximum fundamental frequency of vibration. The method used for solving this optimization problem involves the Rayleigh-Ritz method for the vibration analysis and the simplex method of Nelder and Mead for the iterative search of the optimum support locations. Being a continuum method, the Rayleigh-Ritz method allows easy handling of the changing point support locations during the optimization search. Rectangular plates of various boundary conditions, aspect ratios, composed of different numbers of layers, and with one, two and three internal point supports are analysed. The interesting results on the optimal locations of the point supports showed that (a) there are multiple solutions; (b) the locations are dependent on both the plate aspect ratios and the number of layers (c) the fundamental frequency may be raised significantly with appropriate positioning of the point supports.

• Journal of Korean Library and Information Science Society
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• v.28
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• pp.479-503
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• 1998

This paper examines the effects of the Internet on the librarianship and how the changing roles of libraries and librarians are reshaping the way they serve the users in the information age. Each area of operations and services in a so-called Digital/Electronic Library, which is a phenomenon occurring now not sometime later in the future, is reviewed. The importance of keeping in mind the library' main mission of providing a service, i.e. access to information, is stressed as the pivotal point of librarianship in this global society influenced by the presence of the Internet.

• Proceedings of the KSR Conference
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• 2002.05a
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• pp.228-233
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• 2002

The transition between bridge or tunnel and plain track has different rail pressure and distributed stress on formation. This paper shows distribution of rail pressure on transition at which spring stiffness are changed. By this study, it is revealed that the changing into relatively high stiffness causes increased rail pressure visibly and draw up dynamic track force. A medium stiffness structure and reinforced rail could be effective for reducing track force on the transition.