• Journal of the Korean Society for Precision Engineering
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• v.22 no.10 s.175
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• pp.49-55
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• 2005

The objective of this study was presented with a prediction on the alignment of cementite in pearlite lamella structure of high carbon steel by means of finite-element method(FEM) simulation. Pearlite strcuture was characterized by its nano-sized microstructure feature of alternation ferrite and cementite. FEM simulations were performed based on a suitable FE model describing the boundary conditions and the material behavior. With the alignment of lamella structure in high carbon pearlite steel wire, material plastic behavior was taken into account on plastic deformation and alignment of cementite. The effects of many important parameters(reduction in area, semi-die angle, initial angle of cementite ) on wire drawing process were predicted by DEFORM-2D. As the results, the possibility of wire fracture could be considerably reduced and the productivity of final product could be more increased than before.

• The Research Journal of the Costume Culture
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• v.12 no.1
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• pp.12-27
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• 2004

The Tuck, an important component of modem clothing design, was analyzed through various sources of literature comprised chiefly of domestic and imported fashion magazines from 2000 to 2003. The results were as follows: 1) The Tuck was organized in horizontal, perpendicular, oblique and radial directions. Application methods included repetition, gradation, radial arrangement, sequence and alternation of individual lines. 2) The Tuck was found in a variety of forms and uses. But due to structural characteristics, its function is more psychological and aesthetic than functional. The aesthetic properties of the Tuck included rhythm, optical illusion, abstraction, and material. The structural property of the Tuck occasionally substituted bust or waist darts. 3) The individuality and originality of the Tuck was used in unpredictable ways to give spatial ornamentality and emphasis on material. This enabled aesthetically unique designs to arise. To summarize, the Tuck, a component of clothing design as a formative art, was used in a variety of methods towards developing creative clothing design.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.401-404
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• 2005

Because the underwater structures are subjected to the deterioration according to use environment, it is necessary to repair and reinforce when the durable performance are considered in structures. Epoxy mortar in the underwater used to the repair and reinforcement for durability. Epoxy mortar in the underwater-harding maked epoxy and filler. Filler is divided aggregate and powder system. Because aggregate take a matter too seriously to supply that alternation material is used to rapidly chilled steel slag. As result of study, it is possible that rapidly chilled steel slag can be applied for replacement materials about aggregate in epoxy mortar because the strength is not different.

• Economic and Environmental Geology
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• v.9 no.3
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• pp.157-163
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• 1976

In this study, the oil bearing rock-sequence, U-hand-ri Formation (D.S. Lee et al., 1976), was subdivided into three members; the lower, the intermediate and the upper. The lower consists mainly of reddish purple tuff and sandy calcareous shales, the intermediate of an alternation of tuffs, sandstons, calcareous black shales, cherts and limestone and the upper of coarse grained variegated tuff and agglomerate. Oily matter was found from the black shales of the intermediate. Ten samples of black shales from drilled cores, 8 samples of black shales from different outcrops of the member, and 1 sample of grease-like seeping oil from black shales at U-hang-ri coast were chemically analyized. Among them, 9 samples contain remarkable amount of organic carbon (0.96~1.60%) and E.O.M. extract (0.176~0.718%), and mostly the bituminous material is saturated hydrocarbons as well as shown in infared spectroscopic analyses. The elemental analyses of MAE extracts and asphaltenes of some of thoese samples indicate that the transformation of organic material to crude oil is highly progressed. The authors suggest that the seeping oil and oily tinges in black shale layers are the products of natural cracking related with the igneous activities in the area nearby.

• Journal of the Korean Society for Precision Engineering
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• v.2 no.2
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• pp.69-75
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• 1985

The object of this study is to discuss the effect of cutting fluid on the mechanism of chip formation in orthogonal cutting. Rehbinder effect has been known as a phenomenon, the reduction of mechanical strength, when the metal is exposed in a polar organic environment or the surface of metal is coated with some polar organic substances. About the cause of Rehbinder effect there have been many different ideas by Rehbinder, Merchant, Shaw, Sakakida and etc. In this report, the effects of surface active medium (magic ink) upon the mechanism of chip formation on the orthogonal cutting of copper and the mechanical properties of the work material are experimentally discussed with constant rake angle. Under the condition of polar organic environment the experimental results are as follows; 1) The chip thickness becomes thinner and slip line pitch on the free surface of chip becomes smaller than that of dried cutting area. 2) The order of alternation of cutting ratio was changed. 3) The friction angle on the tool face is not affected by the depth of cut. 4) The cutting force and shear strain on the shear plane decrease remarkably, therefore the work material must be embrittled under polar organic environment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.207-209
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• 2004

Currently, for satisfying the needs of scaled MOSFET's a high quality thin oxide dielectric is desired because the properties of conventional $SiO_2$ film are not acceptable for these very small sized transistors. As an alternative gate dielectric have drawn considerable alternation due to their superior performance and reliability properties over conventional $SiO_2$, to obtain the superior characteristics of ultra thin dielectric films, $N_2O$ grown thin oxynitride has been proposed as a dielectric growtuanneal ambient. In this study the authors observed process characteristics of $N_2O$ grown thin dielectric. In view points of the process characteristics of MOS capacitor, the sheet resistance of 4.07$[\Omega/sq.]$, the film stress of $1.009e^{10}[dyne/cm^2]$, the threshold voltage$(V_t)$ of 0.39[V], the breakdown voltage(BV[V]) of 11.45[V] was measured in PMOS. I could achieve improved electrical characteristics and reliability for deep submicron MOSFET devices with $N_2O$ thin oxide.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.9
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• pp.791-795
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• 2000

Amorphous chalcogenide glasses have a wide variety of light-induced effects. In this study, we have investigated the diffraction efficiency of chalcogenide. As$_{40}$ Ge$_{10}$ Se$_{15}$ S$_{35}$ thin films by the various applied electric fields. The holographic grating in these thin films has been formed using a linearly polarized He-Ne laser light (633nm). The diffraction efficiency was investigated the two method of applied electric field in the perpendicular and parallel to the direction of inducing beam. We obtained that properties of diffraction efficiency in the two methods of applied electric field. The result is shown that the diffraction efficiency of parallel electric field is 285% increase, η=1.1$\times$10$^{-3}$ and the diffraction efficiency of perpendicular electric field is 80% decrease, η=9.83$\times$10$^{-5}$ . Also, we have investigated the anisotropy property on chalcogenide thin films by the electric field effects.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.195-196
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• 2005

In recent years, as the needs of MOS's a high quality is desired to get the superior electrical characteristics and reliability on MOSFET. As an alternative gate dielectric have drawn considerable alternation due to their superior performance and reliability properties over MOSFET, 2'nd silicidation formation process has been proposed as a dielectric growth/annealing process. In this study the author observed process characteristics on MOS structure. In view points of the process characteristics of MOS capacitor, the oxygen & polysilicon was analyzed by SIMS analysis on l'st & 2'nd Ti process, the oxygen and Si2 contents[Count/sec] of 1.5e3 & 3.75e4 on l'st process and l.1e3 & 2.94e4 on 2'nd process, the Ti contents' of 8.2e18 & 6.5e18 on 1'st and 2'nd process. The sheet resistance[$\Omega/sq.$] was 4.5 & 4.0, the film stress[dyne/cm 2] of 1.09e10 & 1.075e10 on l'st and 2'nd process. I could achieved the superior MOS characteristics by 2'nd silicidation process.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.1
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• pp.1-8
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• 2023

In this study, to reduce CO₂ emission in the cement manufacturing process, we evaluated the limestone that is used as a raw material for cement, substituted with steel slag by the various substituted levels. Based on the chemical composition of each raw materials including limestone, and blast furnace slow cooling slag, converter slag, and KR slag as an alternative raw material, we simulated the optimal cement raw mixture by the substitution levels of limestone. Test results indicated that the steel slags contain a certain level of CaO that can be used as alternative decarbonated raw materials, and it has enough to partially reduce the amount of limestonem. And we estimated the maximum usable levels of each raw material. In particular, it was confirmed that by using a mixture of these raw materials rather than using them one by one, the effect of reducing limestone was increased and CO₂ emission from the cement manufacturing process could be reduced.

• Journal of Korean Medicine Rehabilitation
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• v.19 no.1
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• pp.187-199
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• 2009

Objectives : The electroacupuncture was generally has been used in oriental medicine doctors. In recent years, there have been a few studies about safety and stability of acupuncture needle in itself, but then again research of acupuncture needle safety and stability on applying electroacupuncture have been insignificant. Therefore we investigated the safety and change in mechanical characteristic of acupuncture needle in electroacupuncture therapy. Methods : We observed mechanical characteristic change by SEM(Scanning Electron Microscope) and EDX(Energy Dispersive X-ray Spectroscopy), evaluated the hardness by vickers hardness tester. We used MTT assay and cell stain to study about biocompatibility of electroacupuncture. Results : In this study, any corrosion of material, alternation of elements, and change of hardness were not observed in surface analysis using SEM and EDX. In cytotoxity evaluation using MTT assay and cell stain, cell survival rate was low when practicing the electroacupuncture for more than 3 hours. Conclusions : Change of mechanical property was not observed based on the test results using surface analysis and hardness estimation by the electroacupuncture. And considering the biocompatibility, electroacupuncture was thought to be safe in an hour based on cytotoxity evaluation using MTT assay and cell stain.