• Journal of the Korea Society of Computer and Information
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• v.14 no.1
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• pp.117-125
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• 2009

In hybrid wireless networks, a mobile node in MANET can communicate with other mobile nodes as well as nodes in the Internet. Hybrid mobile networks help to expand the application domains of MANET from limited areas, such as military applications to more diverse and general application areas. Previous routing protocols in hybrid wireless networks have not taken advantage of location information of nodes in a network. By using location information of nodes, a routing protocol can reduce the overhead of control messages for efficient network operations. This paper proposes a routing protocol for hybrid mobile networks, called Location-aided AODV+ (LAp) that is based on ADOV+ and takes advantage of node's location information. Performance evaluation shows that LAp performs better than ADOV+ when there are a sufficient number of nodes in a network for route establishments.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.05a
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• pp.39-42
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• 2004

In the present paper, a novel systematic method using the 2-D hybrid special finite elements containing an edge crack is employed to study the fracture behaviors of laser beam spot-welds in automotive structures. 2-D hybrid special finite elements each containing an edge crack can assure the high precision especially in the vicinity of crack tips and give a better description of its singularity with only one hybrid element surrounding one crack. Therefore, the numerical modeling of the laser beam spot-welds can be greatly simplified. Some numerical examples are provided to demonstrate the validity and versatility of the proposed method. All the lap-shear, lap-tension and angle clip specimens are analyzed and some useful fracture parameters (such as stress intensity factors, the initial direction of crack growth) are obtained simultaneously.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.57-60
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• 2005

Composite-to-aluminum joins were tested to get failure loads and modes for three types of joins; adhesive bonding, bolt fastening, and adhesive-bolt hybrid joining. Film type adhesive FM73 and paste type adhesive Cytec EA9394S were used for aluminum and composite bonding to make a double-lap joint. A digital microscope camcorder was used to monitor the failure initiation and propagation. It was found that the hybrid joining is an effective method to strengthen the joint when the mechanical fastening is stronger than the bonding as in the case of using the paste type adhesive. On the contrary, when the strength of the bolted joint is lower than the strength of the bonded joint as in the joint with the film type adhesive, the bolt joining contribute little to the hybrid joint strength.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.3
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• pp.44-50
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• 2006

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.9
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• pp.841-850
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• 2008

Strength and failure of composite-to-aluminum rivetted, bonded, and rivet/bonding hybrid single-lap joints were investigated by experiment. A total of 82 joint specimens were tested with 3 different overlap lengths and 2 types of stacking sequence. FM73m adhesive film and NAS9308-4-03 rivet were used for hybrid joints. While failure loads of the bonded and hybrid joints increased as the overlap length increased, failure loads of the rivetted joints were not affected by the overlap length. Effect of the stacking sequence was not remarkable in the simple bonded or rivetted joints. Failure loads of the hybrid joints, however, showed the maximum of 30% difference depending on the stacking sequence. Major failure mode of the bonded and hybrid joints was the delamination of the composite adherend and failure mode of riveted joints was the rivet failure with local bearing.

• Journal of Korean Society of Forest Science
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• v.43 no.1
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• pp.39-50
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• 1979

Twelve Pinus taeda were used as mother trees and one P. rigida plus tree was used as pollen tree for 12 cross combinations. Nine P. densiflora plus trees(4 mother and 7 pollen trees) were used as parents for 11 cross combinations. Those parents and 10 progenies were analyzed for LAP of ${\times}$P. taeda rigida hybrid and P. densiflora and for peroxidase of ${\times}$P. taeda rigida. The analysis, based on the banding patterns, indicate three alleles for LAP-A locus(A1, A2, A3) and two alleles for LAP-B locus (B1, B2) in ${\times}$P. taeda rigida hybrids. Chi-square test on the segregation for progenies did not show significant differences. The results indicated good agreement with monohybrid Mendelian inheritance. Independence test for occurrence frequency of 2 alleles(LAP-A3, LAP-B2) illustrated that there is neither linkage nor repulsion relationship between LAP-A3 and LAP-B2 alleles. Three band at LAP-A locus were always exhibited from all parents and their progenies of P. densiflora. However, the occurrence of two bands at LAP-B locus was variable, one bands assumed as homozygous alleles(B2/B2) and two bands as heterozygous alleles(B1/B2). The segregation ratio for progenies of P. densiflora suggested that LAP-B locus may be controlled by two alleles(B1 and B2). Three Peroxidase loci(Px-A, Px-B, Px-C) assumed to be controlled by allozyme in ${\times}$P. taeda rigida hybrid. The Px-B and Px-C loci could not find out the variations from banding patterns of parents and their progenies, while the Px-A locus showed the variations of occurrence frequency by two bands. The segregation ratio for A1/A2 at LAP-A locus suggest that the peroxidase allozymes of ${\times}$P. taeda rigida hybrid appeare to be monomeric products; that is, Px-A locus may be controlled by two alleles (A1 and A2).

• Journal of Powder Materials
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• v.20 no.4
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• pp.302-307
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• 2013

A5J32-T4 and A5052-H32 dissimilar aluminum alloy plates with thickness of 1.6 and 1.5 mm were welded by friction stir lap welding (FSLW). The FSLW were studied using different probe length tool and various welding conditions which is rotation speed of 1000, 1500 rpm and welding speed of 100 to 600 mm/min and material arrangement, respectively. The effects of plunge depth of tool and welding conditions on tensile properties and weld nugget formation. The results showed that three type nugget shapes such as hooking, void, sound have been observed with revolutionary pitch. This plunge depth and material arrangement were found to effect on the void and hooking formation, which in turn significantly influenced the mechanical properties. The maximum joint efficiency of the FSLWed plates was about 90% compared to base metal, A5052-H32 when the A5052-H32 was positioned upper plate and plunge depth was positioned at near interface between upper and lower plates.

• Advances in aircraft and spacecraft science
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• v.5 no.5
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• pp.595-613
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• 2018

The objective of our study is to analyze the behavior of bonded, riveted and hybrid (bonded / riveted) steel / steel assemblies by tensile tests and to show the advantage of a hybrid assembly over other processes. the finite element method with the ABAQUS numerical code was used to model the fracture behavior of the different assemblies. Cohesive zone models (CZM) have been adopted to model crack propagation in bonded joints using a bilinear tensile separation law implemented in the ABAQUS finite element code. The riveted assemblies were modeled with the XFEM damage method identified in this ABAQUS numerical code. Both CZM and XFEM methods are combined to model hybrid assemblies. The results are consistent with the experimental results and make it possible to guarantee the validity of the applied numerical model. The use of a hybrid assembly shows a high resistance compared to other conventional methods, where the number of rivets has been highlighted. The use of the hybrid assembly improves mechanical strength and increases service life compared to a single lap joint and a riveted joint.

• Transactions of Materials Processing
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• v.13 no.6 s.70
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• pp.484-489
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• 2004

This paper employed a systematic analysis using a 2-D hybrid special finite element containing an edge crack in order to describe the fracture behavior of spot-welds in automotive structures. The 2-D hybrid special finite element is derived form a mixed formulation with a complex potential function with the description of the singularity of a stress field. The hybrid special finite element containing an edge crack can give a better description of its singularity with only one hybrid element surrounding one crack. The advantage of this special element is that it can greatly simplify the numerical modeling of the spot welds. Some numerical examples demonstrate the validity and versatility of the present analysis method. The lap-shear, lap-tension and angle-clip specimens are analyzed and some useful fracture parameters such as the stress intensity factor and the initial direction of crack growth are obtained simultaneously.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.10a
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• pp.83-87
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• 2004

In this work, the cure cycle of co-cured metal/composite structure was investigated to decrease fabricating thermal residual stresses between the metal and the composite material. DSC (Differential scanning calorimetry) experiment and static lap shear test of co-cured aluminum/composite double lap joint as well as the curvature experiment of co-cured steel/composite strip were performed to investigate the effect of curing cycle on the thermal residual stress of co-cured hybrid structures. From the experiments, it was found that post curing method after abrupt cooling of co-cured aluminum/composite hybrid structure at certain point of degree of cure during curing process could eliminate fabricating the thermal residual stresses.