• Steel and Composite Structures
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• v.15 no.5
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• pp.519-538
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• 2013

The design optimization of a cold-formed steel portal frame building is considered in this paper. The proposed genetic algorithm (GA) optimizer considers both topology (i.e., frame spacing and pitch) and cross-sectional sizes of the main structural members as the decision variables. Previous GAs in the literature were characterized by poor convergence, including slow progress, that usually results in excessive computation times and/or frequent failure to achieve an optimal or near-optimal solution. This is the main issue addressed in this paper. In an effort to improve the performance of the conventional GA, a niching strategy is presented that is shown to be an effective means of enhancing the dissimilarity of the solutions in each generation of the GA. Thus, population diversity is maintained and premature convergence is reduced significantly. Through benchmark examples, it is shown that the efficient GA proposed generates optimal solutions more consistently. A parametric study was carried out, and the results included. They show significant variation in the optimal topology in terms of pitch and frame spacing for a range of typical column heights. They also show that the optimized design achieved large savings based on the cost of the main structural elements; the inclusion of knee braces at the eaves yield further savings in cost, that are significant.

• Computers and Concrete
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• v.16 no.5
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• pp.703-722
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• 2015

This study investigates the performance of advanced hollow reinforced concrete (RC) bridge column sections with triangular reinforcement details. Hollow column sections are based on economic considerations of cost savings associated with reduced material and design moments, as against increased construction complexity, and hence increased labor costs. The proposed innovative reinforcement details are economically feasible and rational, and facilitate shorter construction periods. We tested a model of advanced hollow column sections under quasi-static monotonic loading. The results showed that the proposed triangular reinforcement details were equal to the existing reinforcement details, in terms of the required performance. We used a computer program, Reinforced Concrete Analysis in Higher Evaluation System Technology (RCAHEST), for analysis of the RC structures; and adopted a modified lateral confining effect model for the advanced hollow bridge column sections. Our study documents the testing of hollow RC bridge column sections with innovative reinforcement details, and presents conclusions based on the experimental and analytical findings. Additional full-scale experimental research is needed to refine and confirm the design details, especially for the actual detailing employed in the field.

• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.6
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• pp.72-81
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• 2002

The purpose of this study is to determine the impact of the soil load for artificial ground on a building's structural expenses. Three types of soil - 100% soil, soil mixed with 50% perlite, and 100% artificial soil - were used for this study. A one story concrete steel building specific to each soil load was designed, and then, the cost of steel and concrete used for the design was estimated. As the result of this study, the structural expenses in the case of 5:5 mixed soil can be reduced about 17% compare with 100% soil. Using artificial soil, the structural expenses can be cut about 32% compare to 100% soil and about 12% less when 5:5 mixed soil is used. However, considering total expense which includes the structural expense and soil expense, the expense of 5:5 mixed soil have an increase 25% compared with 100% soil. In the artificial soil, the total expense is 45% more expensive than 100% soil and 17% higher when 5:5 mixed soil is used because of the high unit price of artificial soil. This study expected substantial savings in structural cost as the soil-load was lightened. But, savings were significantly reduced because the unit price of the artificial soil is much more expensive than the price of the natural one. Therefore, further research on methods of reducing the unit price of the artificial soil should be conducted in order to extend green space on to artificial ground.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.878-882
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• 1996

This paper discusses the definition and concepts, approach methodologies, capable application areas in electricity business, and tentative calculation of avoided generation costs based on the Korea's official long-term generation expansion plan. The objective to evaluate avoided costs of a resource is to supply decision makers with the breakeven cost of a targeting avoided resource. For the evaluation of avoided costs of the Korea's generation system, we consider the pseudo-DSM option which has 1,000MW peak savings, load factor with 70 percent, and life-time With 25 years as the avoided resource. The DSM resource can save the fuel and capacity additions of a electric utility during its life time. The capacity and fuel savings are evaluated from the two different cashflows with and Without the DSM option, which are generated on the basis of the generation system optimization model(WASP-II), independently. The breakeven kWh costs of the DSM option over this 25-year period is projected to be 34.1[won/kWh], which is composed of generation-capacity and fuel avoided costs with 101.139[won/kW] and 17.6[won/kWh], respectively.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.8
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• pp.1347-1354
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• 2016

This paper presents optimal operational scheduling model and economic assessment of Li-ion battery energy storage systems installed in non-residential customers. The operation schedule of a BESS is determined to minimize electric bill, which is composed of demand and energy charges. Dynamic programming is introduced to solve the nonlinear optimization problem. Based on the optimal operation schedule result, the economics of a BESS are evaluated in the investor and the social perspective respectively. Calculated benefits in the investor or customer perspective are the savings of demand charge, energy charge, and related taxes. The social benefits include fuel cost savings of generating units, construction deferral effects of the generation capacity and T&D infra, and incremental CO2 emission cost impacts, etc. Case studies are applied to an large industrial customer that shows similarly repeated load patterns according to days of the week.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.523-526
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• 2015

In recent years, building commissioning has often been part of a standard delivery practice in construction, particularly in the high-performance green building market, to ensure the building is designed and constructed per owner's requirements. Commissioning, therefore, intends to provide quality assurance that buildings perform as intended by the design and often helps achieve energy savings. Commissioning, however, is not as widely adopted as its potential benefits are perceived. Owners are still skeptical of the cost-effectiveness claims by energy management and commissioning professionals. One of the issues in the current commissioning practice is that not every project is guaranteed to benefit from the commissioning services. This, coupled with its added cost, the commissioning service is not acquired with great acceptance and confidence by building owners. To overcome this issue, this paper presents a unique methodology to enhance owner's predicting capability of the degree of success of commissioning service using the Bayesian theorem. The paper analyzes a situation where a future building owner wants to use a pre-commissioning in an attempt to refine the success rate of the future commissioned building performance. The author proposes the Bayesian theorem based framework to improve the current commissioning practice where building owners are not given accurate information how much successful their projects are going to be in terms of energy savings from the commissioning service. What should be provided to the building owners who consider their buildings to be commissioned is that they need some indicators how likely their projects benefit from the commissioning process. Based on this, the owners can make better informed decisions whether or not they acquire a commissioning service.

• Journal of Information Technology Applications and Management
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• v.31 no.2
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• pp.15-34
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• 2024

This study aims to analyze the effect of absorptive capacity on technology collaboration performance and the moderating effect of innovation intermediaries. We set absorptive capacity (potential, realized) as independent variables and technology collaboration performance (relative technology level, development period, cost savings, new product development, collaboration satisfaction) as dependent variables, with innovation intermediaries as a moderating variable. We conducted a survey of 145 ICT companies that experienced technology collaboration and analyzed the data using 101 valid responses. The results show that potential absorptive capacity has a significant effect on new product development and collaboration satisfaction, while realized absorptive capacity has a significant effect on relative technology level, cost savings, and new product development. Furthermore, innovation intermediaries have a moderating effect between realized absorptive capacity and new product development. The contribution of this study to academia and industry is that it highlights absorptive capacity as a key factor influencing technology collaboration performance. The limitations of this study include the lack of accurate measurement of absorptive capacity and innovation intermediaries, as well as a lack of control over external factors. These limitations should be addressed through more in-depth research by systematically defining and measuring them in future follow-up studies.

• Computers and Concrete
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• v.19 no.6
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• pp.737-744
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• 2017

Geopolymer Concrete is typically proportioned with activator solution leading to moderately high material cost. Such cost can be enduring in high value added applications especially when cost savings can be recognized in terms of reduction in size of the members. Proper material selection and mix proportioning can diminish the material cost. In the present investigation, a total of 27 mixes were arrived considering the mix parameters as liquid-binder ratio, slag content and sodium hydroxide concentration to study the mechanical properties of geopolymer concrete (GPC) mixes such as compressive strength, split tensile strength and flexural strength. The derived statistical Response Surface Methodology is beleaguered to develop cost effective GPC mixes. The estimated responses are not likely to contrast in linear mode with selected variables; a plan was selected to enable the model of any response in a quadratic manner. The results reveals that a fair correlation between the experimental and the predicted strengths.

• Journal of Korean Institute of Industrial Engineers
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• v.24 no.2
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• pp.175-183
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• 1998

When a product is designed, tolerances must be given to the product so that required functions are guaranteed and production costs are minimized. In this research, a model is suggested which allocates tolerances to components optimally according to the STA(Statistical Tolerance Allocation) method. Taking into account the concept that dimensional errors have characteristics of statistical distributions, this model presents the discrete pseudo-boolean approach for the tolerance optimization by minimizing the tolerance cost and the quality loss cost. In this approach, two methods are proposed for the reduction of the problem scale; 1) a method for converting the minimization model for casts into the maximization model for cost savings, and 2) procedures to reduce the number of constraints and variables.

• KIEAE Journal
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• v.12 no.6
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• pp.63-68
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• 2012

The aim of this study is to evaluate current policies and suggest the way of overcome financial impediments to the energy efficiency function of residential buildings. Based on this analysis the paper enumerates policy recommendations for enhancing how energy efficiency is addressed in building codes and other policies for residential buildings. For achieving this goal, this study conducts the cost-benefit analysis to measure total energy savings and associated total cost. The results of study shows that the cost is greater than the benefit from 1st to 4th year but the benefit will be greater than the cost for the rest of the year. In addition, this study designs a financial support method and an implementation mechanism. Investment from the capital market will take place with the government's interest subsidy. Home retrofit will be undertaken with low interest rate with 2.5% and the return will be paid by a monthly energy bill. The results of this study provides some useful insights for the policy design, including the importance of developing information tools for providing appropriate information to households.