• Journal of Korean Society of Coastal and Ocean Engineers
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• v.26 no.5
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• pp.267-277
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• 2014

The conventional performance-based design method for the solid-wall caisson breakwater has been extended and applied to the perforated-wall caisson. The mathematical model to calculate the sliding distance of a perforated-wall caisson is verified against hydraulic experimental data. The developed performance-based design method is then compared with the conventional deterministic method in different water depths. Both the expected sliding distance and the exceedance percentage of total sliding distance during the structure lifetime decrease with decreasing water depth outside the surf zone, but they increase with decreasing water depth inside the surf zone. The performance-based design method is either more economical or less economical than the deterministic method depending on which design criterion is used. If the criterion for the ultimate limit state is used, the former method is less economical than the latter outside the surf zone, whereas the two methods are equally economical inside the surf zone. However, if the breakwater is designed to satisfy the criterion for the repairable limit state, the former method is more economical than the latter in all water depths.

• Journal of Industrial Technology
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• v.37 no.1
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• pp.32-36
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• 2017

In this study, as part of a research on the development of economical high-performance concrete with high strength and high quality, the physical properties of high-performance concrete were analyzed by substituting a certain amount of low-cost domestic silica fume exempted from the re-importation type distribution structure of the domestic production and the existing high-priced silica fume distribution structure. Performing tests to identify the physical properties of the fresh and hardened concrete and durability analogy of the concrete which use low-cost domestic silica fume and imported silica fume, the chloride ion penetration resistance test result showed that the strength difference between the low-cost silica fume and the imported silica fume is not big but the strength of the low-cost silica fume was measured higher than the imported silica fume. The chloride ion penetration resistance of all variables was measured as "very low". Since the low-cost domestic silica fume can be used as a high-performance admixture of concrete, the results suggest that it is possible to produce a more economical high-performance concrete.

• Geomechanics and Engineering
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• v.32 no.2
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• pp.209-232
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• 2023

A comprehensive study was conducted to design economical foundations for a number of buildings on soft cohesive soil in the southern coastal regions of Iran. Both static and seismic loads were considered in the design process. Cyclic experiments indicated that the cohesive soil of the area has potential for softening. Consequently, the major challenge in the design stages was relatively high dimensions of settlement, under both static and seismic loadings. Routine soil-improvement methods were too costly for the vast area of the project. After detailed numerical modeling of different scenarios, we concluded that, in following a performance-based design approach and applying a special time schedule of construction, most of the settlement would dissipate during the construction of the buildings. Making the foundation as rigid as possible was another way to prevent any probable differential settlement. Stiff subgrade of stone and lime mortar under the grid foundation and a reinforced concrete slab on the foundation were considered as appropriate to this effect. In favor of an economical design, in case the design earthquake strikes the site, the estimations indicate no collapse of the buildings even if considerable uniform settlements may occur. This is a considerable alternative design to costly soil-improvement methods.

• Journal of the Korea Institute of Building Construction
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• v.1 no.1
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• pp.135-142
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• 2001

This study is for the investigation of form using the aluminum-compound metal frame(Aluminum frame reinforced panel : AFR panel) which is improved in the capacity in the wall-concrete structure in steal of using the existing form which has problems such as, excessive exposure of cement, the loss of labor when it is constructed or disjointed, and it's economical efficiency compared with that of EURO Form. AFR panel passes the KS F 8006 test, and as a result of field test, it's displacement is satisfied with Specification. And using AFR panel is more economical than that of EURO Form because saving labor cost which plays a major part in cost saving in formwork is more effective in retrenching total cost than increment of material cost.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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• pp.268-273
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• 2004

The visual environment in an educational building, apart from providing the comfortable seeing conditions needed for the performance of a wide variety of work tasks, must also satisfy the psychological and emotional needs of learners. This paper presents study on actual illumination environment of college and comparison of economical efficiency in order to figure out illumination problems. Furthermore, it attempts to suggest an optimum design of lecture room illumination through computer simulation. We try to evaluate economical efficiency of lighting design in lecture room under the illumination plan which is based on illumination maintenance and uniformity ratio that KS. illumination standard sets.

• Journal of Animal Science and Technology
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• v.44 no.1
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• pp.61-68
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• 2002

This study was conducted to estimate the effects of high quality cubed roughage and red clay (0%, 1%, 2%) on growth performance, meat quality and economical benefits. Thirty-six 6 month-old Korean native cattle, averaging 156kg of BW, were assigned to six groups in a 2 (rice straw : RT, rice straw+cubed roughage : RCT) ${\times}$ 3 (0, 1, 2% red clay). During experimental period, the high quality cubed roughage added into rice straw treatment (RCT) was superior to the only rice straw treatment (RT) on daily gain and feed efficiency and final weight 10%, 6.8%, 8.2% (P$<$0.05) respectively. But the addition of red clay did not affect and even 2% addition decreased those parameters. For meat quality and economical analysis, the addition of high quality cubed roughage made an outstanding result and for RT treatment, only 1% red clay indicated good effects while both 1% and 2% red clay were better than 0% for RCT treatment. From these results, it is assumed that the addition of red clay for fattening Korean native cattle has no effects on growth performance but 1% treatment has good results on improving meat quality and economical benefits. It also suggests that the combination high quality roughage and concentrated red clay is beneficial for producing high quality meat in with economical benefits.

• Journal of the Korean Home Economics Association
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• v.50 no.7
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• pp.1-12
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• 2012

The purpose of this study was to identify the factor structure of self-efficacy, consumer behavior, and the learning effects of the unit 'Consumption Life' and to study the effects of self-efficacy on the consumer behavior, and the learning effects of the unit 'Consumption Life'. Questionnaires were administered to 370 female middle school students living in the Metropolitan City of Daegu. The data was analyzed by using the frequency, descriptive statistics, factor analysis, reliability analysis, multiple regression, and t-test. The findings are as follow. Self-efficacy was composed of five factors such as the capability in work performance, rational performance, fear, anxiety, and the ability to challenge oneself. Consumer behavior was composed of five factors such as emphasis on product display, emphasis on information, emphasis on fashion, emphasis on appearance, and the products/information exchange. The learning effects of the unit 'Consumption Life' was composed of two factors in the economical consumption, and rational consumption. The effects of consumer behavior and the learning effects of the unit 'Consumption Life' on each of the self-efficacy factors like the capability in work performance, rational performance, fear, anxiety, the ability to challenge oneself were explained by factors such as emphasis on product display, emphasis on information, emphasis on fashion, emphasis on appearance and products/information exchange, and economical consumption and rational consumption.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.7
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• pp.474-481
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• 2010

Because international environmental and energy problems such as global warming and ozone depletion, exhausting of fossil energy sources are more serious than before, renewable energy system is attracting people's attention more and more. Organic waste bioenergy system among a variety of renewable energy system is expected to have an effect on building a society which is eco-friendly and recycles resources owing to carbon neutral effects. So this is considered as the role of an energy source of the building. Previous studies on the organic waste bioenergy are mainly bioenergy technology and activation plan of the bioenergy supply. But the performance evaluation studies of bioenergy systems installed in buildings are rarely. This study is to evaluate applicability of the organic waste bioenergy system as the building energy supply system by energy and environmental, economical analysis.

• Journal of the Korean Society for Heat Treatment
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• v.24 no.3
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• pp.160-170
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• 2011

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.6
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• pp.763-778
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• 2019

Abrasive waterjet cutting technology has been used for rock excavation of tunnels and underground structures due to various advantages. In order to cut rocks by using the abrasive waterjet system, abrasive is essential to enhance impact energies for fracturing the target rock. Since garnet abrasives are not produced in Korea, alternative abrasives, instead of garnets, are needed to achieve the economical waterjet cutting. This study is to analyze cutting performance for rocks with sandy particles as alternative abrasive. Cutting tests were carried out on granite specimens at the constant waterjet energy (e.g., water pressure or water flow rate). The five kinds of sands, sampled by construction fields and natural sites, were prepared to perform the experimental tests. When sea sand was used as an alternative abrasive, cutting performance was secured to be 60~70% compared to the commercial garnet abrasive. Thus, it is expected that sand abrasives can be applied on the waterjet cutting process for the economical excavation construction.