• Computers and Concrete
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• v.3 no.5
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• pp.313-334
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• 2006

A novel formulation aiming to achieve optimal design of reinforced concrete (RC) structures is presented here. Optimal sizing and reinforcing for beam and column members in multi-bay and multistory RC structures incorporates optimal stiffness correlation among all structural members and results in cost savings over typical-practice design solutions. A Nonlinear Programming algorithm searches for a minimum cost solution that satisfies ACI 2005 code requirements for axial and flexural loads. Material and labor costs for forming and placing concrete and steel are incorporated as a function of member size using RS Means 2005 cost data. Successful implementation demonstrates the abilities and performance of MATLAB's (The Mathworks, Inc.) Sequential Quadratic Programming algorithm for the design optimization of RC structures. A number of examples are presented that demonstrate the ability of this formulation to achieve optimal designs.

• Journal of the Korean Statistical Society
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• v.3 no.1
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• pp.3-12
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• 1974

The two-stage sequential test, suggested by Baker [2] for testing hypotheses $H_0:\mu=\mu_0$ and $H_1:\mu=\mu_1$ of $N(\mu,\sigma^2)$ with the unknown $\sigma^2$ would not be amenable for applications unles some cluses on the choice of the first-stage sample size are available. The study in this paper is intended to shed some light on the size of the first-stage sample. An approximate method is used to estimate an optimal initial sample size that minimizes the average sample number. In brief, the optimal size is a strictly monotone decreasing function of the quantity $(\mu_1-\mu_0)/\sigma$. Empirical and simulation results are used to ascertain the negligible effect of possible errors due to approximations and assumptions used.

• Journal of Navigation and Port Research
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• v.29 no.5 s.101
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• pp.421-429
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• 2005

Traditionally, determination of the optimal containership size is the most important factor for competitiveness of shipping companies in the shipping market. Under this environment, many shipping companies and researchers have studied about it. The objective of this research is to determine the optimal containership size using a total shipping cost in the main trunk lines. Total shipping cost is calculated at the ground of capital costs, vessel operation costs, voyage costs, port charges and miscellaneous costs for 'Europe-Far East', 'Far East-North America' and 'Europe-Far East-North America' services. Analysis results showed that the 6,500TEU containership is an optimal size on the 'Europe-Far East' and 'Europe-Far East-North America' services. And the 8,200TEU containership is an optimal size on the 'Far East-North America' service. Moreover, if the larger containerships over 8,200TEU class start operation afterward, it would be less competitive in the analyzed 3services.

• Journal of Electrical Engineering and Technology
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• v.13 no.4
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• pp.1549-1557
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• 2018

Optimizing the design of large-scale electric machines based on nonlinear finite element analysis (FEA) requires longer computation time than other applications of FEA, mainly due to the huge size of the machines. This paper addresses a new region decision method (RDM) with mesh adaptive direct search (MADS) for the optimal design of wind generators in order to reduce the computation time. The validity of the proposed algorithm is evaluated using Rastrigin and Goldstein-Price benchmark function. Moreover, the algorithm is employed for the optimal design of a 5.6MW interior permanent magnet synchronous generator to minimize the torque ripple. Additionally, mechanical stress analysis as well as electromagnetic field analysis have been implemented to prevent breakdown caused by large centrifugal forces of the modified design.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.10
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• pp.5149-5167
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• 2017

Reducing energy consumption in a wireless video sensor network (WVSN) is a crucial problem because of the high video data volume and severe energy constraints of battery-powered WVSN nodes. In this paper, we present an adaptive dynamic resizing approach for a SRAM communication buffer in a WVSN node in order to reduce the energy consumption and thereby, to maximize the lifetime of the WVSN nodes. To reduce the power consumption of the communication part, which is typically the most energy-consuming component in the WVSN nodes, the radio needs to remain turned off during the data buffer-filling period as well as idle period. As the radio ON/OFF transition incurs extra energy consumption, we need to reduce the ON/OFF transition frequency, which requires a large-sized buffer. However, a large-sized SRAM buffer results in more energy consumption because SRAM power consumption is proportional to the memory size. We can dynamically adjust any active buffer memory size by utilizing a power-gating technique to reflect the optimal control on the buffer size. This paper aims at finding the optimal buffer size, based on the trade-off between the respective energy consumption ratios of the communication buffer and the radio part, respectively. We derive a formula showing the relationship between control variables, including active buffer size and total energy consumption, to mathematically determine the optimal buffer size for any given conditions to minimize total energy consumption. Simulation results show that the overall energy reduction, using our approach, is up to 40.48% (26.96% on average) compared to the conventional wireless communication scheme. In addition, the lifetime of the WVSN node has been extended by 22.17% on average, compared to the existing approaches.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.7
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• pp.4999-5008
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• 2015

The application of efficient constraint handling technique is fundamental method to find better solutions in engineering optimization problems with constraints. In this research four of constraint handling techniques are used with a meta-heuristic optimization method, harmony search algorithm, and the efficiency of algorithm is evaluated. The sample problem for evaluation of effectiveness is one of the typical discrete problems, optimal pipe size design problem of water distribution system. The result shows the suggested constraint handling technique derives better solutions than classical constraint handling technique with penalty function. Especially, the case of ${\varepsilon}$-constrained method derives solutions with efficiency and stability. This technique is meaningful method for improvement of harmony search algorithm without the need for development of new algorithm. In addition, the applicability of suggested method for large scale engineering optimization problems is verified with application of constraint handling technique to big size problem has over 400 of decision variables.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.834-839
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• 2004

In this paper, we investigate the optimal base position and joint configuration of a planar wheeled mobile manipulator in terms of manipulability measure. Taking into account the level of coordination between a manipulator and a platform, both local and global optimization problems are considered. First, based on the kinematic models of a mobile manipulator, the manipulability measures are expressed along with the analysis of the configurational dependency. Second, the geometric symmetry of a mobile manipulator in view of manipulability measure is analyzed, and for some base positions, the best and worst joint configurations are determined, Third, with reverence to the maximum, minimum, and average manipulability measures, the optimal base positions are determined, and the percent improvements due to the base relocation are discussed considering the relative scales among the platform size, the wheel radius, and the link length.

• Fashion & Textile Research Journal
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• v.11 no.6
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• pp.918-924
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• 2009

As the population of overweight and obese children is rising rapidly around the world, there are many researches on purchasing and wearing children's clothing and optimal sizes, but researches on obese children are still inadequate. This study was carried out on 192 obese children over 75% in BMI. The purpose of the study was to set up the optimal interval of sizing system using the loss function which would be a guide for obese children for selecting ready to wear of suitable size. Introducing a loss function, which reflects how much the purchasing desire changes according to the difference, we formulate the problem and suggest a procedure to determine the optimal standard sizes minimizing the loss. These results were as follows ; In size chart of top's, 4 sizes had been determined by a loss function, had covered more than 91.1% of all subjects. In size chart of bottom's, 5 sizes had been determined by a loss function, had covered more than 87.0% of all subjects.

• International Journal of Control, Automation, and Systems
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• v.1 no.2
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• pp.163-170
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• 2003

The optimal Bayesian filter for a single target is known to provide the best tracking performance in a cluttered environment. However, its main drawback is the increase in memory size and computation quantity over time. In this paper, the inevitable predicament of the optimal Bayesian filter is resolved in a suboptimal fashion through the use of a receding horizon strategy. As a result, the problems of memory and computational requirements are diminished. As a priori information, the horizon initial state is estimated from the validated measurements on the receding horizon. Consequently, the suboptimal algorithm proposed allows for real time implementation.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.2
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• pp.252-262
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• 2004

A model of simultaneous heat and mass transfer process in absorption of refrigerant vapor into a lithium bromide solution of water-cooled vertical plate absorber. which was considered to the change of refrigerant vapor pressure along the plate width direction. was developed to evaluate the compactness of plate absorber and supply basis data for optimal design of plate absorber. The effects of plate interval as well as the effect of capacity for one piece of plate absorber on plate absorber size such as plate height. plate heating area and plate absorber volume have been investigated. It is confirmed that there is exist an optimal plate interval minimizing plate absorber volume. And the smaller capacity for one piece of plate absorber. the smaller plate absorber volume is obtained.