• Journal of Conservation Science
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• v.26 no.2
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• pp.171-182
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• 2010

The slag excavated from Gyesil-ri in Gongju, Yeonje-ri in Cheongwon and Beopcheonsaji (temple) site in Wonju are analyzed by X-ray Fluorescence Analyzer, metallurgical microscope, SEM-EDS etc., for chemical composition and microstructure to figure out the raw material and the iron manufacturing technique. First of all, as a result of principal component analysis, the total Fe-content of slag from Gyesil-ri is 39 to 44% and the modified rate is 15 to 21%, which is common in ancient iron slag. Yeonje-ri site is found the ancient iron-smelting furnace. The total Fe-content of slag from Yeonje-ri is 41 to 43% and modified rate is 18~30%, which is also the general value in the ancient slag. However only slag is excavated in the residential area at Beopcheonsaji site and there is no iron making relic. In addition, the result of principal component analysis contains that the total Fe-content of Beopcheonsaji site is 52 to 57%, and modified rate is 8 to 14%. It shows that the total Fe-content of Beopcheonsaji site is higher than relic from Gyesil-ri and Yeonje-ri and the modified rate is lower than other sites. This results mean that recollecting rate of Fe in Beopcheonsaji site is lower than other sites. Also, as a result of minor elements analysis, the slag from Gyesil-ri has the higher level of Ti, V and Zr than other sites and the microstructure are observed as magnetite and ulvospinel, so that the raw material of slag is iron sand. But the slag from Yeonje-ri and Beopcheonsaji site are identified to use iron ore. As a result of microstructure observation, fayalite, gray-columnar crystal, is found in the slag from Yeonje-ri and big wustite as main phase is observed in the slag from Beopcheonsaji site. This study show that the slag from Yeonje-ri is made of smelt ash produced during smelting works and the slag from Beopcheonsaji site is made of forging ash produced during forging work concerning the excavated location and the microstructure.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.1
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• pp.107-113
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• 1992

This paper is the part of fundamental study considering whether the unprocessed water cooled blastfurnace slag, by-product of iron works, can be useful for some fine aggregate of mortar and concrete. The acquired results in this study show that the qualities of the water cooled blastfurnace slag produced in the state of raw material in the country in not good for using as a fine aggregate of mortar and concrete. To be used as a fine aggregate of concrete the qualities need to be improved in the process of manufacture.

• International Journal of Precision Engineering and Manufacturing
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• v.2 no.4
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• pp.47-53
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• 2001

This study is to investigate the problem of the SPM(Skin Pass Mil7) system which is a finishing treatment of steel sheet. and to develop a PID control scheme to minimize process instability. An electrohydraulic servo system with conventional proportional controller used to regulate the force on the strip works inadequately to yield very undesirable transient responses at the moments welding parts of the strip conte into and pass through the rolls. Both linearized and nonlinear models of a typical SPM system ware simulated first by using Simulink. Then Ziegler-Nichols ultimate cycling method was used for an initial reference guide to tune PID gains, and further fine tuning was performed to get desirable response. The test result in the plant show that proposed PID control scheme successfully improves the process instability in a SPM system.

• Steel and Composite Structures
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• v.1 no.1
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• pp.131-144
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• 2001

Overpressurization can occur due to the ignition of flammable vapors existing inside aboveground oil storage tanks. Such accidents could happen more frequently than other types of accident. In the tank design, when the internal pressure increases, the sidewall-to-roof joint is expected to fail before failure occurs in the sidewall-to-bottom joint. This design concept is the socalled "frangible roof joint" introduced in API Standard 650. The major failure mode is bifurcation buckling in this case. This paper presents the bifurcation buckling pressures in both joints under internal pressure. Elastic and elastic-plastic axisymmetric shell finite element analysis was performed involving large deformation in the prebuckling state. Results show that API Standard 650 does not evaluate the frangible roof joint design conservatively in small diameter tanks.

• Journal of the Korea Safety Management & Science
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• v.6 no.3
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• pp.131-140
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• 2004

The company was focusing on production which was partial mission rather than acquiring the information of customer in intensive process industry. The company accepted loss which is from over-production, losing of opportunity. After changing to web environment, supply chain is more complicated and need of customer is more various. As a result the company hard works on controlling production rates, production quantities in production area and gathering exact information which is about available resource and available quantities. Cooperated demand planning have to get decreasing of inventory, improving of customer service in supply chain management. Specially demand planning that considers allocation of capacity is executed in Iron-Industry. Demand planning must be classified by customer, region and supply position level.

• Plant Journal
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• v.5 no.4
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• pp.80-85
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• 2009

LNG stevedoring plant offshore pipelines requires human power and the longest construction period in constructing LNG storing terminal and influences on the success of the project absolutely. In this paper, the constructing procedures of LNG stevedoring plant offshore pipeline was established. Establishment of constructing procedures of LNG stevedoring plant offshore pipeline includes procurement of main equipments, iron frame and pipelines. To predict any expectable problems, that may occur by the stage of construction the application to the field works with a base of theoretical and practical contents for the constructing procedures of LNG stevedoring plant offshore pipelines can be established.

• Plant Journal
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• v.5 no.4
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• pp.73-79
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• 2009

Increase of consumption in limited coal reserves leads prices surging. As a result, iron works which produce products with coal are in difficulties. Accordingly, it is required a lot of research of using non-caking coal that is relatively low cost and has abundant reserves. Direct drying and indirect drying are two major methods of drying the coal. Recently, to minimize the needed calories and to save energy, using fluidbed or fluidizing method is a recent main trend of minimizing the size of the facility and maximizing energy efficiency. However there is also disadvantage such as increasing facility investment because of installing additional facilities in the latter part. In this study, we will have theoretical researches on the indirect drying method with heat exchange system which have been traditionally used. As a result it is expected to increase the efficiency of the facility operation.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.995-998
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• 1995

As the modern industrial processes become more complex, it is getting more difficult to model and control the processes. Naturally, an advanced type of DCS(Distributed Control System) with higher level functions is being sought Advanced DCS is a DCS with advanced functions such as fault diagnosis, GPC(Generalized Predictive Control), NN(Neural Network), and Fuzzy Control. In this thesis, we have studied a fuzzy control algorithm for realizing an advanced DCS. Its algorithm is implemented in a form of function code which is a process control language, being used by the industrial engineers. To verify the realized function code of the fuzzy control, the function code is applied to a continuous casting process of the Pohang Iron & Steel Works in Kwangyang. The rules of the fuzzy control were collected via interviews of the field operators and their operation documents. Finally, usability of the function code of the fuzzy control is shown via simulation for the continuous casting process model.

• Journal of Korean Society of Water and Wastewater
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• v.13 no.1
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• pp.134-139
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• 1999

This study was conducted to determine the effects of water aggressivity on the corrosion in a recirculating pipe loop systems. As the pH was increased in the range of pH 6.0~8.5, water aggressivity was decreased. Zine and iron concentration of water adjusted by pH were lower than those of tap water and water adjusted by alkalinity and calcium hardness. The major elements of corrosion deposit analyzed by EDS(Energy Dispersion Spectrophotometer) were zinc and calcium. In conclusion, we suggest that in corrosion control practice in the water works industry, increasing the pH of the water can serve as a way of controlling the solubility of metal ions release from water distribution systems.

• Bulletin of the Korean Chemical Society
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• v.1 no.4
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• pp.117-121
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• 1980

The effect of lateral intermolecular interactions among the adsorbate molecules has been incorporated into the theory of multilayer physical adsorption developed previously by the present authors within the frame of Bragg-Williams approximation and the resulting adsorption isotherm has been used to interpret the adsorption data of tetramethylsilane vapor on clean iron film which we failed to account for in our previous works. The result has shown that up to the point where the relative pressure is about 0.7 considerable improvement is obtained but beyond this point there still remains large difference between theoretical and experimental isotherm. Such difference is supposed to arise from the neglect of effect of vertical interaction between the adsorbate molecules and the adsorbent surface.