• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.79-90
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• 1995

The material handling equipment selection, that is a key task in the material handling system design, is a complex, difficult task, and requires a massive technical knowledge and systematic analysis. It is invaluable to justify the selected equipment model by the performance evaluation before its actual implementation. This paper presents an intelligent knowledge-based expert system called "IMESE" created by authors, for the selection and evaluation of material handling equipment model suitable for movement and storage of materials in a manufacturing facility. The IMESE is consisted of four modules: a knowledge base to select an appropriate equipment type, a multiple criteria decision making procedure to choose the most favorable commercial model of the selected equipment type, a database to store the list of commercial models of equipment types with their specifications, and simulators to evaluate the performance of the equipment model. The whole process of IMESE is executed under VP-Expert expert system environment.vironment.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.576-580
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• 2008

Rubber material properties and useful life evaluation are very important in design procedure to assure the safety and reliability of the rubber components. In this paper, the evaluation of characteristics and useful life prediction of rubber component for elevator cabin were experimentally investigated. The material test and accelerated heat-aging test were carried. Rubber material constants were obtained by curve fittings of simple tension, pure shear and bi-axial tension test data. Heat aging test results changes as the threshold are used for assessment of the useful life and time to threshold value were plotted against reciprocal of absolute temperature to give the Arrhenius plot. By using the rubber material and component test several useful life prediction equations for rubber component were proposed. Predicted useful life of rubber component for elevator cabin agreed fairly with the experimental lives.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1-6
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• 2008

Due to the self-similarity of Berkovich and conical indenters, different materials may show the same loaddepth curve for single indentation. In this study, we first compare the load-depth characteristics of conical and Berkovich indenters via finite element method. We also analyze the variation of load-depth curves with angle of Berkovich indenter, indentation parameters, and material properties. With numerical regressions of obtained data, we then propose dual-Berkovich indentation formulae for material property evaluation. The proposed approach provides the values of elastic modulus, yield strength and strain-hardening exponent and corresponding stress-strain curve with an average error of less than 3%. The method is valid for any elastic indenters made of tungsten carbide and diamond for instance.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.21-24
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• 2007

This paper deals with introduction of testing equipments for the evaluation of dynamic tensile characteristics of auto-body steel sheets and the crashworthiness of auto-body members. The servo-hydraulic high speed material testing machine was developed for tensile tests at the intermediate strain rate to obtain the tensile material properties at the strain rate under 500/sec. The split Hopkinson bar apparatus using the elastic wave was developed for dynamic material characteristics at the high strain rate ranged from 1,000 to 10,000/sec. The servo-hydraulic high speed crash testing machine is the equipment for the evaluation of the collapse load and crashworthiness of auto-body members. High speed carrying truck crashes to specimen with the maximum velocity of 17 m/sec.

• Nuclear Engineering and Technology
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• v.55 no.3
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• pp.1191-1198
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• 2023

Bentonite buffer material is a critical component in an engineered barrier system (EBS) for disposing high-level radioactive waste (HLW). The bentonite buffer material protects the disposal canister from groundwater penetration and releases decay heat to the surrounding rock mass; thus, it should possess high thermal conductivity, low hydraulic conductivity, and moderate swelling pressure to safely dispose the HLWs. Bentonite clay is a suitable buffer material because it satisfies the safety criteria. Several additives have been suggested as mixtures with bentonite to increase the thermal-hydraulic-mechanical-chemical (THMC) properties of bentonite buffer materials. Therefore, this study investigated the geotechnical, mineralogical, and THMC properties of several candidate additives such as sand, graphite, granite, and SiC powders. Datasets obtained in this study can be used to select adequate additives to improve the THMC properties of the buffer material.

• KIEAE Journal
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• v.10 no.6
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• pp.123-130
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• 2010

Indoor air quality has attracted great attention in recent years and thus the importance of managing finishing materials in terms of pollutant source control is being emphasized. Managing the finishing material at the design stage maximizes the efficiency of IAQ control at the following construction stage. However, there are insufficient investigations on the application of a specific finishing material management process, a database management system or a finishing material management process network. As a result, the main purposes of this study comprise comprehensive evaluation of IAQ performance from the selected finishing materials and auxiliary materials, application of the material management system basing on the types and characteristics of toxic substances generated from the indoor finishing materials, investigation of IAQ evaluation standard, and the overall IAQ evaluation method for the design parts. The result of this study will be the basic data to construct DBMS for management of finishing materials with respect to IAQ.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.664-667
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• 2004

It may have to establish the definite standard for performance evaluation basis about cementitious waterproofing material in job site that applied the method of construction formed cement waterproof course on concrete surface In present paper shows the effective selection method of waterproof layer of optimum thickness for economic performance as evaluating of the need thickness on waterproof property of penetrating waterproofing material.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.05a
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• pp.167-171
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• 2006

In this study, for the establishment of the performance evaluation methods of repair material and method for reinforced concrete structure and the quality control standards of durability recovery method, the quantitative exposure data by exposure experiment under the coastal and normal atmosphere environment is accumulated and analyzed. Investigating and evaluating the result of exposure experiment during 30 months of exposure age under the coastal and normal atmosphere environment, carbonation depth and chlorideion penetration depth very little penetrated than cover depth. It seems reasonable to conclude that main cause of corrosion of reinforcing bar are inner chloride-ion and macro cell from the result of corrosion area and corrosion velocity. Accordingly, it is considered that fundamental data on the performance evaluation and quality control standards of repair material and method could be presented through continuous exposure test in the future.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.789-794
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• 2002

The relationship is investigated between material modeling of concrete and the evaluation procedure of thermal stress by the hydration heat. In this respect, some important points are suggested to which special attention should be paid to reasonably evaluate the thermal stress using the widely-used structural analysis programs. This study indicates that proper material model should be used to draw incremental stress evaluation that takes into account the change of elastic modulus with time. Some correction techniques are also presented when using the program that don't have proper built-in procedure for the calculation of the thermal stress.

• Journal of the Korea Institute of Building Construction
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• v.7 no.2 s.24
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• pp.99-106
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• 2007

The purpose of this study presents in Relations between cracks in self-leveling material and quality of floor groundwork surface are experimentally examined. As the first stage, the experiment to observe cracks in self-leveling material constructed on floor groundwork made from various kinds of concrete was carried. As a result, following basic findings were obtained. First, observation of cracks should be continued until an increase in width of cracks stop, without constructing any finishing material. Second, degree of cracks may be indicated quantitatively by the product of length and width. Finally, Cracks and separation is not be influenced by specimen size. Based on these findings, the method of predicting cracks by evaluating surface layer quality of floor groundwork will be established.