• Nonlinear Functional Analysis and Applications
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• v.27 no.2
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• pp.233-247
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• 2022

In the present manuscript, we employ the concepts of Θ-map and Φ-map to define a strong (𝜃, 𝜙)s-contraction of a map f in a b-metric space (M, d_b). Then we prove and derive many fixed point theorems as well as we provide an example to support our main result. Moreover, we utilize our results to obtain many results in the settings of metric and G-metric spaces. Our results improve and modify many results in the literature.

• Journal of the Earthquake Engineering Society of Korea
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• v.1 no.1
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• pp.1-10
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• 1997

Current seismic design philosophy for reinforced concrete (RC) structures on energy dissipation through large inelastic defomations. A nonlinear dynamic analysis which is used to represent this behavior is time consuming and expensive, particularly if the computations have to be repeated many times. Therefore, the selection of an efficient yet accurate alogorithm becomes important. The main objective of the present study is to propose a new technique herein called the prediction approach with siffness measure (PASM) method in the convetional direct integration methods, the triangular decomposition of matrix is required for solving equations of motion in every time step or every iteration. The PASM method uses a limited number of predetermined decomposed effective matrices obtained from stiffness states of the structure when it is deformed into the nonlinear range by statically applied cyclic loading. The method to be developed herein will reduce the overall numerical effort when compared to approaches which recompute the stiffness in each time step or iteration.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.1
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• pp.13-22
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• 2013

This paper deals with a novel method for numerical analyses of the tapered geometrical non-linear beam with three unknown parameters, subjected a floating point load. The beams with hinged-movable end constraint are chosen as the objective beam. Cross sections of the beam whose flexural rigidities are functionally varied with the axial coordinate. The first order simultaneous differential equations governing the elastica of such beam are derived on the basis of the Bernoulli-Euler beam theory. A novel numerical method for solving these equations is developed by using the iteration technique. The processes of the solution method are extensively discussed through a typical numerical example. For validating theories developed herein, laboratory scaled experiments are conducted.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.3
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• pp.311-317
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• 2013

In this paper, we proposed high speed LDPC decoding algorithm based on DVB-S2 standard for applying marine communications in order to multimedia transmission. For implementing the high speed LDPC decoder, HSS algorithm which reduce the iteration numbers without performance degradation is applied. In HSS algorithm, check node update units are update at the same time of bit node update. HSS can be accelerated to the decoding speed because it does not need to separate calculation of the bit nodes, However, check node calculation blocks need many clocks because of just one memory is used. Therefore, this paper proposed partial memory structure in order to reduced the delay and high speed decoder is possible. The results of the simulation, when the max number of iteration set to 30 times, decoding throughput of HSS algorithm is 326 Mbit/s and decoding speed of proposed algorithm is 2.29 Gbit/s. So, decoding speed of proposed algorithm more than 7 times could be obtained compared to the HSS algorithm.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.2
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• pp.137-146
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• 2005

This study presents the shape iteration method and the updated Lagrangian methods to calculate the initial tension and the reference length of cables of cable-stayed bridges. The girders and towers of cable-stayed bridge are modelled as 3-dimensional frame elements and the cable as nonlinear truss element or Ernst's cable element. Compared with the initial tensions of cables by finite element method in this study and by trial-and error method in practices, the tensions by the former are shown to be a little less than the those by the latter. The reference lengths of cables by Ernst's cable elements are almost consistent with those of cables by nonlinear truss elements. And the reference length of cables in this study are almost consistent with the arc length of beam with the same initial tension. Therefore the reference lengths of cables in cable-stayed bridges are shown to be obtained simply by the theory of beam with the initial tension calculated in this study.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.1
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• pp.337-346
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• 2013

A design collaboration system for a plant project is a set of complicated multidisciplinary processes in which a large number of various engineering fields are involved. Each subsystem is related to each other as they depend on information that other subsystems create, which leads to inefficient design iterations. This study presents an optimal design collaboration system for a plant project using Design Structure Matrix (DSM). Data regarding design subsystems, parameters, etc. were obtained by expert surveys and workshops. An automatic analysis program for DSM was developed using Visual Basic Application and Matlab to provide a partitioned DSM. A case study was conducted on a furnace project; consequently, the optimal design collaboration system with five crucial iteration groups was derived.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.41 no.1
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• pp.33-40
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• 2004

The divide-and-conquer method is efficiently used in parallel multiplier over finite field $GF(2^n)$. Leone Proposed optimal stop condition for iteration of Karatsuba-Ofman algerian(KOA). Ernst et al. suggested Multi-Segment Karatsuba(MSK) method. In this paper, we analyze the complexity of a parallel MSK multiplier based on the method. We propose a new parallel MSK multiplier whose space complexity is same to each other. Additionally, we propose optimal stop condition for iteration of the new MSK method. In some finite fields, our proposed multiplier is more efficient than the KOA.

• Particle and aerosol research
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• v.13 no.1
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• pp.1-10
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• 2017

Accurate prediction of size, shape and velocity of a bubble rising through a liquid pool is very important for predicting the particulate removal efficiency in pool scrubbing, for designing engineering safety features to prepare for severe accidents in nuclear power plants, and for predicting the emission of fission products from MCCI (molten core-concrete interaction) process during severe accidents. In this review article, previous studies on the determination of the size, shape and rising velocity of a bubble in liquid are reviewed. Various theoretical and parameterization formulas calculating the bubble size, shape and velocity from physical properties of liquid and gas flowrate are compared. Recent studies tend to suggest simple parameterizations that can easily determine the bubble shape and rising velocity without iteration, whereas iteration has to be performed to determine the bubble shape and velocity in old theories. The recent parameterizations show good agreement with measured data obtained from experiments conducted using different liquid materials with very diverse physical properties, proving themselves to be very useful tools for researchers in related fields.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.11
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• pp.705-715
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• 2016

In this study, the cycle performance of an air conditioner with multi-indoor units is analyzed and simulated. The cycle performance could be predicted through the integration of mathematical formulation for these devices. The condenser pressure is obtained by an iteration process to match the mass flow rates of the compressor and the expansion valve and the evaporator pressure is determined by an iteration process, in which the suction super heat is tracing the targeted super heat. The required software was developed by system programming. the software algorithm is extended to predict the cycle performance of an air conditioner system with multi-indoor units, and then the numerical results are compared with experimental results. This mathematical model is validated from the result of experiments conducted on 8.3kW air conditioner. The errors in capacity, electronic power, and COP are found to be within 10% in general.

• Journal of Korean Association for Spatial Structures
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• v.20 no.2
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• pp.51-58
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• 2020

Recently, deep learning that is the most popular and effective class of machine learning algorithms is widely applied to various industrial areas. A number of research on various topics about structural engineering was performed by using artificial neural networks, such as structural design optimization, vibration control and system identification etc. When nonlinear semi-active structural control devices are applied to building structure, a lot of computational effort is required to predict dynamic structural responses of finite element method (FEM) model for development of control algorithm. To solve this problem, an artificial neural network model was developed in this study. Among various deep learning algorithms, a recurrent neural network (RNN) was used to make the time history response prediction model. An RNN can retain state from one iteration to the next by using its own output as input for the next step. An eleven-story building structure with semi-active tuned mass damper (TMD) was used as an example structure. The semi-active TMD was composed of magnetorheological damper. Five historical earthquakes and five artificial ground motions were used as ground excitations for training of an RNN model. Another artificial ground motion that was not used for training was used for verification of the developed RNN model. Parametric studies on various hyper-parameters including number of hidden layers, sequence length, number of LSTM cells, etc. After appropriate training iteration of the RNN model with proper hyper-parameters, the RNN model for prediction of seismic responses of the building structure with semi-active TMD was developed. The developed RNN model can effectively provide very accurate seismic responses compared to the FEM model.