• Computers and Concrete
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• v.10 no.3
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• pp.295-306
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• 2012

Optimum cost design of a simply supported reinforced concrete beam is presented in this paper. In the formulation of the optimum design problem, the height and width of the beam, and reinforcement steel area are treated as design variables. The design constraints are implemented according to ACI 318-08 and studies in the literature. The objective function is taken as the cost of unit length of the beam consisting the cost of concrete, steel and shuttering. The solution of the design problem is obtained using the artificial bee colony algorithm which is one of the recent additions to metaheuristic techniques. The artificial bee colony algorithm is imitated the foraging behaviors of bee swarms. In application of this algorithm to the constraint problem, Deb's constraint handling method is used. Obtained results showed that the optimum value of numerical example is nearly same with the existing values in the literature.

• Wind and Structures
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• v.20 no.4
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• pp.489-508
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• 2015

In this paper, a novel methodology is proposed to obtain optimum location of outriggers. The method utilizes genetic algorithm (GA) for shape and size optimization of outrigger-braced tall structures. In spite of previous studies (simplified methods), current study is based on exact modeling of the structure in a computer program developed on Matlab in conjunction with OpenSees. In addition to that, exact wind loading distribution is calculated in accordance with ASCE 7-10. This is novel since in previous studies wind loading distributions were assumed to be uniform or triangular. Also, a new penalty coefficient is proposed which is suitable for optimization of tall buildings. Newly proposed penalty coefficient improves the performance of GA and results in a faster convergence. Optimum location and number of outriggers is investigated. Also, contribution of factors like central core and outrigger rigidity is assessed by analyzing several design examples. According to the results of analysis, exact wind load distribution and modeling of all structural elements, yields optimum designs which are in contrast of simplified methods results. For taller frames significant increase of wind pressure changes the optimum location of outriggers obtained by simplified methods. Ratio of optimum location to the height of the structure for minimizing weight and satisfying serviceability constraints is not a fixed value. Ratio highly depends on height of the structure, core and outriggers stiffness and lateral wind loading distribution.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.9 no.2
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• pp.127-138
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• 1991

This is a study on the selection of the optimum route using geographic information system. In general, the selection of route was classifed in order of candidate route zone, optimum route zone and optimum route, this study comes under optimum route that is the last part in the route planning. The optimum route is get attined on the weighted matrix table that based on landuse status, land value, slope degree of each grid cell of the test area, and also we suggest application possibility of geographic information system in the route planning with the comparision and analysis of the three selection route in this study.

• Journal of the Korean Wood Science and Technology
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• v.40 no.2
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• pp.78-90
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• 2012

Soybean hull is an attractive feedstock for glucose production. To increase the glucose conversion in acid hydrolysis, a pretreatment method combined steam explosion with alkali pretreatment for soybean hull was studied. For first step pretreatment, steam explosion conditions (log Ro 2.45) were optimized to obtain maximum solid recovery and cellulose content. In the second step pretreatment, the conditions for potassium hydroxide pretreatment of steam exploded soybean hull were optimized by using RSM (response surface methodology). The optimum conditions for minimum lignin content were determined to be 0.6% potassium hydroxide concentration, $70^{\circ}C$ reaction temperature and 198 min reaction time. The predicted lignin content was 2.2% at the optimum conditions. Experimental verification of the optimum conditions gave the lignin content in similar value with the estimated value of the model. Finally, glucose conversion of pretreated soybean hull using acid hydrolysis resulted in $97.1{\pm}0.4%$. This research of two-step pretreatment was a promising method for increasing the glucose conversion in the cellulose-to-glucose process.

• Journal of Pharmaceutical Investigation
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• v.21 no.1
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• pp.23-32
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• 1991

Dissolution profiles of ketoconazole in solid dispersion system (SDS) were investigated in the second fluid (pH 6.8) for the dissolution test (KPV). PVP K-30 and methyl cellulose were used as carriers in SDS, and chloroform as a solvent. Computer optimization technique was applied to obtain an optimum formula of SDS, and the following results were obtained; 1) Dissolution rate of ketoconazole in SDS was larger than that of pure ketoconazole in the second fluid of pH 6.8. 2) PVP K-30 and methyl cellulosr were good carriers for SDS of ketoconazole. Moerover PVP K-30 was better than methyl cellulose. 3) The optimum formula of ketoconazole SDS obtained from computer optimization technique was chloroform 175 ml, PVP K-30 5g and methyl cellulose 0.2g per 1g of ketoconazole. 4) The experimental value of $A_{60}$ (Amount released from ketoconazole tablet during 60 minutes) obtained from SDS by optimum formula agreed well with the value calculated by polynomial regression equation.

• Journal of Korean Society for Quality Management
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• v.38 no.4
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• pp.540-548
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• 2010

We consider the problem of selecting the most profitable initial process mean and length of production cycle for manufacturing processes subject to a constant linear trend during the same cycle that varies after resetting the processes. Assuming that the quality characteristic of interest is normally distributed, the optimum initial process mean and the length of production cycle are jointly obtained by minimizing the expected loss per unit time. We assume that the quality loss function due to the deviation from the target value is quadratic and resetting loss is constant. We consider both cases of symmetric and asymmetric quality loss function. An illustrative example is given and sensitivity analysis performed.

• Journal of the Korean Institute of Landscape Architecture
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• v.24 no.2
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• pp.13-24
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• 1996

The purpose of this study is to suggest optimum level of the Ratio of Greenery within the frame of vision in the interior landscape design through the analysis of visual character and preference of the interior landscape. The concept of the RG was defined as the ratio of projected area of plants higher than 1.2M against background wall from eye level. 5 photography of Interior landscape space -- 10,20,30,40 and 50% of the RG-- were constructed by computer graphic techinques. Likert scale and semantic differential scale were used to analyse visual character and preference of the interior landscape space. The analysis results are as follows : 1. Factors that compose of the image of the interior landscape have been found to be the "evaluation ", "complexity". The mean value of semantic differential scale showed a significant difference according to RG. When the RG was 20~30%, "Harmony" and "stability" was strongly recognized than the other factors and the interior landscape made the interior space natural and intimate. But at the RG 40!50%, users felt "stuffy" and "too complex" by many plants, so it was not efficient the Interior Landscape. 2. The visual preference was significantly different according to RG. The mean value of the visual preference was increased as the RG was higher, it was the highest at the RG 30%. But over the RG 30%, the preference level was declined. 3. Based on these results, this study suggests that the optimum level of RG in the Interior Landscape is 30%.at the optimum level of RG in the Interior Landscape is 30%.

• Geomechanics and Engineering
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• v.24 no.3
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• pp.237-251
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• 2021

The main purpose of this study is to investigate the performance of the proposed hybrid teaching-learning based optimization algorithm on the optimum design of reinforced concrete (RC) cantilever retaining walls. For this purpose, three different design examples are optimized with 100 independent runs considering continuous and discrete variables. In order to determine the algorithm performance, the optimization results were compared with the outcomes of the nine powerful meta-heuristic algorithms applied to this problem, previously: the big bang-big crunch (BB-BC), the biogeography based optimization (BBO), the flower pollination (FPA), the grey wolf optimization (GWO), the harmony search (HS), the particle swarm optimization (PSO), the teaching-learning based optimization (TLBO), the jaya (JA), and Rao-3 algorithms. Moreover, Rao-1 and Rao-2 algorithms are applied to this design problem for the first time. The objective function is defined as minimizing the total material and labor costs including concrete, steel, and formwork per unit length of the cantilever retaining walls subjected to the requirements of the American Concrete Institute (ACI 318-05). Furthermore, the effects of peak ground acceleration value on minimum total cost is investigated using various stem height, surcharge loads, and backfill slope angle. Finally, the most robust results were obtained by HTLBO with 50 populations. Consequently the optimization results show that, depending on the increase in PGA value, the optimum cost of RC cantilever retaining walls increases smoothly with the stem height but increases rapidly with the surcharge loads and backfill slope angle.

• Journal of Animal Science and Technology
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• v.60 no.2
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• pp.1.1-1.6
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• 2018

Background: Maize fodder is being used as staple feed for livestock but it lacks protein and essential amino acids; lysine and tryptophan. Intercropping maize with leguminous soybean crop is promising technique under limited land resources of South Korea but it can only give considerable advantages when adequate distance is provided between corn and soybean rows. Main aim of present study was to find-out adequate distance between corn and soybean seeding rows for optimum growth, yield and nutritive value of intercropped forage. Methods: Different interrow distances between corn and soybean were evaluated under four treatments, viz. 1) Corn sole as positive control treatment 2) Zero cm between corn and soybean (control); 2) Five cm between corn and soybean; 3) 10 cm between corn and soybean, with three replicates under randomized block design. Results: Findings depicted that height and number of corn stalks and ears were similar (P > 0.05) among different treatments. Numerically average corn ear height was decreased at zero cm distance. Dry matter percentage in all components; corn stalk, corn ear and soybean was also found not different (P > 0.05) but dry matter yield in component of corn ear was lower (P < 0.05) at zero cm distance as compared to that of 5 and 10 cm interrow distances. In case of nutritive value, total digestible nutrient yield in intercropped corn was also found lower (P < 0.05) at zero cm distance than that of 5 and 10 cm interrow distances between corn and soybean seeding rows. Substantial decrease in dry matter yield of maize ear at zero cm distance might be attributed to factor of closed interrow spacing which made interplant competition more intensified for light interception, necessary for photosynthetic activity. Lower dry matter yield in ear also reduced total digestible nutrients in intercropped maize because it was determining factor in calculation of digestible nutrients. The optimum yield and nutritive value of forage at wider interrow distance i.e. 5 cm between corn and soybean might be due to adequate interseed distance. Conclusion: Conclusively, pattern of corn and soybean seeding in rows at 5 cm distance was found suitable which provided adequate interrow distance to maintain enough mutual cooperation and decreased competition between both species for optimum production performance and nutritive value of intercropped forage.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2000.11a
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• pp.259-277
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• 2000

In this paper, we suggest theoretical grounds on the problem of R&D portfolio with different option premiums utilizing the Real Options Model, which has received intensified attention as the method of assessment of R&D project with high risk. Even though there have been many studies focused on the evaluation of option value of single project from technology valuation's perspective. there are few study on the portfolio of multiple technology investment by option value using. This paper bears practical importance by showing simple examples with the option value of investment alternatives and the valuation of related risk, the construction of optimum portfolio in technology investment alternatives.