• Transactions of Materials Processing
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• v.7 no.3
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• pp.282-290
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• 1998

In bulk metal forming processes prediction of tool life is very important for saving production cost and achieving good material properties. Generally the service life of tools in metal forming process is limited to a large extent by wear, fracture and plastic deformation of tools. In case of hot and warm forging processes tool life depends on wear over 70%. In this study finite element analyses are con-ducted to warm and hot forging by adopting suggested wear model. By comparison of simulation and eal profile of die suggested wear model. By comparison of simulation and real profile of die suggested model is verified.

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.1
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• pp.51-56
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• 2001

This study was carried out to interpret mathematically hydraulic behaviour in packing tower which packed 50 mm plastic Hiflow-ring with a dimension of 300 mm wide and 1,400 mm high. In view of energy saving, the recent packing. 50 mm plastic Higlow-ring was superior to conventional packings because of low pressure drop in high loads. As relative error between numerically predicted and experimentally obtained values was less then 6% in the loading and flooding point, it found that therir results appeared to be adequate. Comparison of hose two values in both dry and wet packing conditions. relative errors amount to 3.96 and 5.6%, respectively. In order to evaluate the operating characteristics of packing, the type, size, and material for packings must be estimated in various system and loads. This study is able to calculated pressure drop, hold-up, gas and liquid loads using mathematical interpretation. For these calculation, the specific constants of each packings must be calculated first all. The method of mathematical interpretation in this study turned out to be superior to the existing methods because of reduced errors at loading and flooding point.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.5
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• pp.430-437
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• 2004

This paper is intended as an investigation of study on the thermal and electrical characteristics of the carbon heating element. In this experimentation, the electric material used is the crystalline graphite a kind of natural graphite. The bentonite is used to solidify the heating element and the vacuum furnace is used for sintering it. It is noted that the natural drying time should be at least 58 hours. The plating of the electric pole with the electroless nickel showed the lowest contact resistance among others. The resistance shows linear variation with regard to length. For the insulation and resolution, the glaze coating is best with 80% of water content. The temperature rising characteristic of the heating element is better than sheath heater saving 43% of rising time. The correlation equation for temperature was obtained with the electric power.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.695-698
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• 2002

Induction heating process is one of the most efficient heating process in terms of temperature control accuracy and heating time saving. In the past study, fabrication process of cellular 6061 alloys by powder metallurgical route and induction heating process was studied. To supplement the framing conditions that studied in past study, effect of induction heating capacity and holding time at foaming temperature were investigated. Under the achieved framing conditions, teamed 6061 alloys were fabricated for variation of foaming temperature, and porosities(%)-foaming temperature curves were obtained by try-error experimental method. Uniaxial compression tests were performed to investigate the relationship between porosities(%) and stress-strain curves of framed 6061 alloy. Also, energy absorption capacity and efficiency were calculated from stress-strain curves to investigated. Moreover, dependence of plateau stress on strain rate was investigated in case of cellular 6061 alloy with low porosities(%)

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.3
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• pp.81-88
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• 2013

Recently, energy-saving technology is rapidly becoming a crucial issue for mankind due to the depletion of natural resources. From this perspective, every automobile manufactures are trying to develop light materials and to validate safety with environmental consideration. In this study, we developed clutch connector tube which is the parts of power transferring clutch with light materials to substitude for existing general steel materials. We also verified that the general steel materials can be replaced with nylon, fiberglass, stainless and plastic materials or not. As a result, we verified that the mixture of glass and nylon composite material can substitude the general steel.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.10
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• pp.23-27
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• 2011

In this paper, material handing cleanroom stocker system for thin film solar cell line of photovoltaic industry and liquid crystal display line of flat panel display industry was selected for the study. Optimum solution for stocker system's CPS(Contactless Power Supply) is approached by changing the motion pattern, optimizing design & production, and analyzing characteristics of the power system. As a result, acceleration time of X-Axis changed from 3 sec to 4 sec, changed the input characteristic of CPS within approximately 11[kW]. This result shows that extending acceleration time of the X-Axis in Stocker Crane's motion pattern can reduce the capacity of the CPS, thus saving the manufacturing cost.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.261-264
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• 2006

Many process parameters have an effect on the auto-body panel forming process. A well-designed blank shape causes the material to flow smoothly, reduces the punch and yields a product with uniform thickness distribution. Therefore, the determination of an initial blank shape plays the important role of saving time and cost in the auto-body panel forming process. For these reasons, some approaches to estimate the initial blank shape have been implemented in this paper, the one-step approach by using a finite element inverse method will be introduced to predict the initial blank shape the developed program is applied to auto-body panel forming.

• Journal of the Korean housing association
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• v.10 no.4
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• pp.147-159
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• 1999

As we have come to realize the problems caused by the modern civilization as well as the importance of the preservation of nature. Ecological building and urban design come to attract more attention. Therefore, the object of this study is providing the design factors and improving the design methods for the developments of ecological housing complex, harmonious with environment. Followings are the results of this study: 1. We need to turn to new trend-Ecological architecture which enables the co-exitence of nature and human being to come over the presence and face new decades. 2. Ecological architecture is based on energy-saving system and give people a healty and comfortable atmosphere. 3. In the city area, the house development should be undertaken to minimize the environmental problem through extremely high ehhiciency and technonogy. 4. We need a new development to preserve natural environment in the suburvan and small or medium city. 5. We have to develope the approach method, which is to maintain the frame of present ecological environment, to be in sympathy with geomorphology, to use the natural material in the rural community.

• Journal of the Korea Concrete Institute
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• v.12 no.3
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• pp.87-94
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• 2000

Disposal of casting foundry fly ash generally depends on reclamation up to the present. This is the great loss from a standpoint of saving resources and utilizing industrial wastes. Therefore, a study on the reuse of fly ash as a substitute material for construction is necessary in order to utilize industrial wastes, to reduce cost and improve quality in producing concrete products, and to protect environment from pollution. In this study, methods for the reuse of the casting foundry fly ash, industrial wastes products, as an admixture for concrete are discussed. For this purpose, fly ash was extracted from casting foundry and tests of physical and chemical properties are executed. Also, various characteristics of concrete using fly ash as an admixture are experimented. Finally, the reuse methods for casting foundry fly ash are presented.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.11a
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• pp.245-246
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• 2011

In recent research in this emerging and latent heat storage material features an innovative temperature - controlled Phase Change Materials to evaluate the superior thermal performance would like to calculate the thermal conductivity. Specified in KS F 4040 test specimen dimensions were equivalent in specifications, test methods according to KS L 9016 was an experiment in progress. As a result, the thermal conductivity of plain cement mortar mixed with more PCM came out with low thermal conductivity of mortar, thermal performance was excellent.