• The KIPS Transactions:PartA
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• v.13A no.3 s.100
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• pp.199-204
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• 2006

The kernel hardening function is necessary in terms of kernel stability to reduce the system error or panic due to the kernel code error that is made by program developer. But, the traditional kernel hardening method is difficult to implement and consuming high cost. The suggested kernel hardening function that makes high availability system by changing the panic() function of inside kernel code guarantees normal system operation by recovering the incorrect address of the kernel stack frame. We experimented the kernel hardening function at the network module of the Linux by forcing panic code and confirmed the proposed design mechanism of kernel hardening is working well by this experiment.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.1
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• pp.173-180
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• 2007

This paper designs the kernel hardening function by recovering the kernel stack fame to reduce the system error or panic due to the kernel code error. The suggested kernel hardening function guarantees normal system operation by recovering the incorrect address of the kernel stack kernel. The suggesting kernel hardening mechanism is applied to the network module of Linux which is much using put. I experimented the kernel hardening function at the network module of the Linux by forcing panic code.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.937-940
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• 2006

According to the analysis of tension failure mechanism of UHSC specimen, one modified model based on ACK model by the introduction of partial debonding energy of non-first cracks and by the application of steel fiber number on unit area is presented in this paper. It can be used to explain the evolution mechanism of multiple cracking and pseudo strain hardening of UHSC. From the numerical results, to increase steel fiber length and to reduce steel fiber diameter in some region all can reduce the fiber volume fraction with the same multiple cracks for economic design of UHSC.

• Journal of Welding and Joining
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• v.8 no.3
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• pp.31-38
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• 1990

The bonding mechanism and bond strength were investigated for the cold pressure welding of Al to Al, Cu to Cu and Al to Cu by upsetting. A phenomenon of bonding betweenthe metallic components has been observed by a scanning electron microscope and metallurgical microscope. A modified equation for bond strength with respect to the reduction of height shows reasonably a good agreement with the experimental data. When the values of the hardening factor and threshold deformation for the given materials could be determined, the theoretical bond strength can be calculated.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.283-283
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• 2013

Because of beautiful glossy and color, the value of gold leverage is very high in Europe. To improve the quality of gold alloys, we performed heat treatment on 14 K white gold alloys by variously changing age-hardening conditions. Age-hardening behavior and the related phase transformation changes were studied to elucidate the hardening mechanism of 14 K white gold alloy. For solid solution treatment [ST], casted gold alloy specimens were treated at high temperature ($750^{\circ}C$) for 30 minutes, and the specimens dropped to water to quench them. For Age-hardening treatment [AT], the specimens were treated at various temperatures ($250{\sim}300^{\circ}C$). After the heat treatment, we observed the phenomenon to increase hardness from 126 Hv to 166 Hv by Vicker's hardness tester. Through electron probe micro-analysis (EPMA) mapping analysis, we investigated that irregular particles were changed uniformly. In the SEM and OM images, two phases of matrix and particle-likestructures were observed, and the precipitation of these elements from the matrix progressed during age-hardening. By transmission electron microscope and X-ray diffraction observation, it was revealed that the formation of the Au3Cu superstructure contributed to the age-hardening at $270^{\circ}C$ in the gold alloy. After the heat treatment, this analysis shows that casted gold alloys were to improve hardness and to moderate surface defects at specific temperatures and duration.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.11a
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• pp.103-106
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• 2008

Because the physical·chemical properties of bottom ash are inferior, most bottom ash is disused. But the use of bottom ash helps in reducing environmental pollution and solving some bottom ash waste problems. So, we have been investigating about the optimum mixture, hardening mechanism, curing condition and environmental safety of a paste composed of a bottom ash and alkali. optimal mixing proportion of bottom ash solid was cement 5%, water 30%, NaOH 10%. After curing during 28days, bottom ash solid can be achieved compressive strength 15.13MPa. As a result, Compressive strength tests of alkali-activated bottom ash have potential as a replacement of coarse aggregate.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.1
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• pp.104-111
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• 1997

Accounting for the additional damages come out from non-proportional loading path effect, material damage according to crystal structure dependence was studied. Microscopic observations of damaged material by SEM(Scanning Electron Microscope) showed crystal structure dependence. Biaxial in-phase loaded specimens showed the slips of same direction, which pararell each other, but biaxial 90.deg. out-of-phase loaded specimens showed multiply crossed slips. S. H. Doong and D. F. Socie reported that wavy/planar or planar slip material showed the increase in the cyclic hardening level during non-proportional cycling. From these results, the additional hardening and non-proportional loading effects were related with slip mechanism, and the slip mechanism was related with crystal structure. In the present study, a damage mechanism which accounts for the non-proportional loading effect from crystal structure dependence was considered and applied to A17075-T651.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.4
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• pp.85-92
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• 2014

The disposal of the paper mill sludge and the paper mill sludge ash become more important issue, because the environment regulation becomes more strict. In this study, the new mulching system was developed by using the paper sludge ash. The soil surface hardening mechanism for mulching with paper sludge ash, red clay and coal ash was evaluated. Since the CaO in the paper sludge ash provided the harden structure with water, the surface hardening mulching structure could cover the field surface and prevent the germination of weeds. More than 50 w.t.% of red clay and 10 w.t.% of paper sludge ash were required to create the solid soil surface structure for mulching. The field test with the new soil surface hardening mulching system for three months showed the generation of weeds could successfully be inhibited by the system.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2006.04a
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• pp.150-151
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• 2006

• Journal of the Society of Naval Architects of Korea
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• v.50 no.1
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• pp.41-48
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• 2013

Several fatigue damages have recently been reported which cannot be resolved in the context of the existing fatigue design procedure, and they are suspected to be the cracks induced by the low cycle fatigue mechanism. To tackle the problem, a series of material tests together with fatigue tests have been carried out, and elasto-plastic notch strain analysis using nonlinear kinematic hardening model has been performed. The cyclic stress-strain curves are obtained and the nonlinear kinematic hardening model was calibrated based on the obtained material data. Also, the fatigue test with non-load-carrying cruciform fillet welded joint has been performed in low cycle fatigue regime. Then, the notch strain analyses have been carried out to find the precise elasto-plastic behavior of the material at the notch root of the cruciform joint. The variation of the material property from the base metal via HAZ up to the weld metal was taken into account using spatial variation of the material property. Then the detail elasto-plastic behavior of the welded joint subjected to the repeated cyclic loading has been investigated further through the comparison with the prediction with Neuber's rule. The calibration of the nonlinear kinematic hardening model and nonlinear notch strain analyses have been performed using the commercial FE program ABAQUS.