• 전기학회논문지P
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• 제58권2호
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• pp.190-195
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• 2009

Thin-gauged 3% silicon steel sheets having a highly grain-oriented texture have been developed as a core material for applications of middle-frequency (400 Hz ${\sim}$ 10 kHz) devices. The newly developed sheets with a tension coating showed an excellent reduction in iron loss at 400 Hz (iron loss at 1.0 T and 400 Hz = 4.677 W/kg, iron loss at 1.5 T and 400 Hz = 9.742 W/kg) due to high magnetic induction, $B_{10}$(measured induction at 1000 A/m), of over 1.9 T. In cases of frequencies below 400 Hz, magnetic induction, $B_{10}$, of the sample plays a major role to reduce its iron loss as excitation induction increases, whereas, in case of frequency of 1 kHz, thickness dependence becomes dominant due to a lower iron loss at relatively thinner sample. The sheets with a high magnetic induction, therefore, are favorable for high excitation induction (over 1.0 T) and low excitation frequency (below 400 Hz) applications, whereas the sheets that can reduce eddy current loss by reducing thickness or domain wall width are advantageous for low excitation induction (below 1.0 T) and high excitation frequency (around 1 kHz) applications.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.669-672
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• 2003

3D object recognition is difficult but important in computer vision. The important thing is to understand about the relationship between a geometric structure in three dimensions and its image projection. Most 3D recognition systems construct models either manually or by training the pose and orientation of the objects. But both approaches are not satisfactory. In this paper, we focus on a commercial CAD model as a third type of model building for vision. The models are expressed in Initial Graphics Exchanges Specification(IGES) output and reconstructed in a pinhole camera coordinate.

• 한국대기환경학회지
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• 제20권4호
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• pp.571-578
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• 2004

The purpose of this study is to estimate of emission factors of the air pollutants for the melting furnaces for the iron and steel industry. The result of this study is able to obtaine the emission factor of particulate matters (PM), sulfur dioxide. nitrogen oxides for melting furnace. The emission factors of each pollutants were as follows : - the emission factor varied between 6.13E-03~6.12E-01 kg/ton for PM -1.59E-01~2.45E+00kg/ton for $SO_2$ - 6.82E-02~6.88E-01 kg/ton for NOx, respectively. Analysis of the differences in the emission factors of ours and U.S. EPA's yielded the following results for the Wilcoxon method : p>0.05. The statistical analysis showed no differences in the our emission factors and U.S. EPA's

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.755-758
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• 2001

Most of the waste plastics are incinerated and landfilled now, leading to much environmental problems. The technology of injection into the blast furnace was developed as a useful recycling method of waste plastics, and applied to the actual operation in several ironmaking companies. We carried out the test operation to inject continuously the two kinds of waste plastics through four tuyeres of the Foundry blast furnace in POSCO by 130 ton of total amount. From this test operation, we analyzed the coke replacement ratio, the permeability, the heat load and other changes of furnace conditions with the injection of waste plastics into the blast furnace. Some trials based upon the theoretical approaches were applied to examine the efficiencies of blast furnace.

• 헤리티지:역사와 과학
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• 제35권
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• pp.138-158
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• 2002

To compare and analyze technical system related to manufacturing of ironware during the period of the Three Kingdoms, an analysis was conducted on the minute system of metalwork, as study objects, of the remains of the Mt. Wolpyeong fortress wall in Daejeon in the period of capital during the era of the Three Kingdoms in the 5th century, the Sanwol-ri remains in the 6th century in Gunsan and the remains of ironware excavated from the great ancient tomb of Hwangnam of the Silla dynasty in the 5th century. The result of analysis shows that in the most of the casting products, the minute system of white cast iron were contained. While the iron part of decarbonization was in the system by casting as white cast iron in the central part, on the surface layer it was turned out that comparatively uniform 100% pearlite system of about 1~2mm degree was existing. The part of pearlite on the surface layer was caused by decarbonization, which appears in all the parts of blade front end and handle. Therefore, it was found that the iron part of decarbonization was manufactured by casting, and then was processed at the high temperature by decarbonization. For the products of forging, after processing the products on the basis of pure iron for materials, they manufactured the ironware that raises the strength by carbonizing that keeps carbon infiltrated on the necessary part, by the method of black smith welding that add pure iron to steel, or by varying the method of heat processing onto the part required of strength. Though limited, we could understand that the technical systems for manufacturing skill of ironware in the areas of Baekje and Silla were different each other. In the technical system for Hwangnam great ancient tomb in the Silla area, it is found that they had raised the strength on the necessary part by applying the steelmaking method of carbonizing in the last stage of production of products, in the meantime in Baekje area, it appears that they had produced steel in advance in the first stage of production of the products, and used the produced steel only to the necessary part.

• 전기학회논문지
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• 제61권9호
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• pp.1269-1274
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• 2012

In this paper, the iron loss was calculated using estimated iron loss coefficient at 650W Interior Permanent Magnet Synchronous Motor(IPMSM) and 250W IPMSM. The iron loss coefficients was estimated different according to electrical steel material used to stator and rotor core in motor. Aspect of The rotating flux field and alternating flux field was confirmed by magnetic field behavior and harmonic analysis in stator core, the iron loss was calculated using flux density by Finite Element Method(FEM) and estimated coefficients by iron loss coefficient estimation proposed in this paper. The iron loss experiment was performed for verified to iron loss calculation, and the iron loss coefficients were verified by comparison of iron loss calculation value and experimental value.

• 한국표면공학회지
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• 제26권3호
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• pp.109-114
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• 1993

Black magnetite film could be formed on Invar steel for shadows mask by iron electroplating in thickness of 0.46~0.63$\mu\textrm{m}$ on Invar steel and subsequent oxidation of iron by immersion in strongly alkaline soution for 30~60 minutes. blackness degreed of magnetite oxide film on Invar was C20BL90 in comparision of color chart of Dainippon Ink & Chemicals Inc. Co. and adhesion test showed excellent adhesion of oxide film on substrate. Magnetite oxide film grew up on iron in hot strongly alkaline solution according to 'Sato-Cohen' oxide film growth model.

• 제어로봇시스템학회논문지
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• 제21권8호
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• pp.709-712
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• 2015

This paper will introduce the development case study about virtual-reality-based operation training system for steel making process. Steel making process consist iron making process to create liquid steel, pig iron, by reduction process, steel making process to make molten steel by refining, continuous casting process to make slab, and rolling process to make final product like coil, plate. This steel making process deals with liquid and solid products, so facilities of steel making process are very various and complicated. In addition, according to various customer requirements, the recycle of facilities and recipes changing have been fast. So the training for skilled operators is very important point. In this paper, we develop steel making training system based virtual reality for training skilled operator. This system consists of virtual machine, virtual HMI, and virtual control panel. And for fitting the characteristics of each process and increasing the education effectiveness, we develop dynamic methods like the method of dynamic education system configuration, initial facilities setup operation education system, and etc.

• Journal of Mechanical Science and Technology
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• 제16권4호
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• pp.501-511
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• 2002

This paper presents a study of the effect of rolling temperature, roll gap (pass height), initial specimen size and steel grades of specimens on the roll force in round-oval-round pass sequence by applying approximate method and verifications through single stand pilot rod rolling tests. The results show that the predicted roll forces are in good agreement with the experimentally measured ones. The approximate model is independent of the change of roll gap, specimen size and temperature. Thus, the generality of the prediction methodology employed in the approximate model is proven. This study also demonstrates that Shida's constitutive equation employed in the approximate model needs to be corrected somehow to be applicable for the medium and high carbon steels in a lower temperature interval (700∼900$\^{C}$).

• Journal of Advanced Marine Engineering and Technology
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• 제23권3호
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• pp.284-291
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• 1999

Recently the ductile cast iron is being used successfully to the parts for processing machinery vessels and gear etc. This study is mainly concerned with the heat treatment for the specimens of crank shaft which are made of ductile cast iron. The results obtained are summarized as follows. Comparing the mechanical properties of the specimens for the normalized ductile cast irons the specimen heat treated at $550^{\circ}C$ was the best for crank shaft of air-compressor. After austenizing at $910^{\circ}C$ it was observed that the higher the reheating temperature is the less tensile strength and the hardness became which was supposedly attributed to the fact that the amount of pearlite. Austenite matrix was reduced by reheating after normalizing and that as the reheating tem-perature went up the pearlite generated was less and the distance between the pearlites were widened at last made pearlite globular. In the comparsison of crank shaft for air compressor made of ductile cast iron with that made by forged steel the crank shaft made of ductile cast iron was superior in economical terms. And ductile cast iron could be practically enough if only the elonga-tion which was inferior mechanical property to forged steel could be reinforced by increasing the diameter of crank pin when designing the crank shaft.