• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1784-1787
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• 2008

Molecular dynamics (MD) simulations are used to analyze behavior of copper nanowires under cyclic loading. The embedded atom method (EAM) potential is employed to represent atomic interaction. Cyclic load is applied in two ways (Forward Tension / Reverse Compression and Forward Compression / Reverse Tension). The results show that dislocations are piled up as a result of plastic deformation during alternate tensile and compressive loading. After cyclic loading with a change of direction, yield stress decreases in consequence of the effect by the dislocation pileups. On the other hand, under FC/RT cyclic load, phase transformation represent associated with mechanical twinning. And copper nanowire can return to almost former undeformed condition during tensile loading at 300K.

• Transactions of Materials Processing
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• v.13 no.8
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• pp.731-737
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• 2004

Mechanical properties such as Young's modulus and hardness of thin film in coated steel are difficult to determine by nano-indentation from the conventional analysis using the load-displacement curve. Therefore, an analysis of the nano-indentation loading-unloading curve was used to determine the Young's modulus, hardness. A new method is recently being developed for elastic-plastic properties of materials from nano-indentation. Elastic modulus of the thin films shows relatively small influence whereas yield strength is found to have significant effect on measured data. The load-displacement curves of material tested with a Berkovich indenter and nano-indentation continuous stiffness method is used to measure the modulus and hardness through thin films, and then these are computed using the analysis procedure. The developed neural networks apply also to obtain reliable mechanical properties.

• Korean Journal of Environmental Agriculture
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• v.38 no.3
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• pp.145-153
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• 2019

BACKGROUND: The 'Gamhong' cultivar, middle season apple with big fruit size and high soluble solid content, has been bred in Korea. However, it was hard to cultivate the cultivar in Korea by serious bitter pit. The relationships between shoot growth, fruit size, and bitter pit may be affected by crop load. This study was conducted for 2 years (7~8 years after planting) to investigate vegetative growth, fruit quality, bitter pit incidence, return bloom, and gross income for optimum crop load of 'Gamhong'/M.9 adult apple tree. METHODS AND RESULTS: The crop load was assigned to 4 different object ranges as follow: 45~64, 65~84, 85~104, and 105~124 fruits per tree. The vegetative growth, average fruit weight, percentage of fruits heavier than 375 g, soluble solid content, and return bloom increased significantly at the crop load range of 45~64 fruits. However, the lowest total gross income per tree may have been caused by the highest bitter pit incidence and the lowest yield per tree in any other crop load range. The total gross income and yield per tree increased significantly at the crop load range of 105~124 fruits and return bloom dropped to 40%, and hence it was possible to occur biennial bearing. It was 85~104 fruits that biennial bearing did not occur and total gross income was as high as the crop load range of 105~124 fruits. Also, the yield of high grade fruits per tree, with fruit weight of 400~499 g and none bitter pit on fruit surface, was highest at the crop load range of 85~104 fruits, compared to other crop load range. CONCLUSION: In considering fruit size, bitter pit incidence, return bloom, and gross income, the optimum crop load range of 'Gamhong'/M.9 adult apple tree in high density orchard was 85~104 fruits per tree.

• Journal of the Korean Geotechnical Society
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• v.22 no.11
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• pp.65-73
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• 2006

Reliability between safety factor and reliability index for driven and bored pile load capacity was analyzed in this study. 0.1B, Chin, De Beer, and Davisson's methods were used for determining pile load capacity by using load-settlement curve from pile load test. Each method defines ultimate yield and allowable pile load capacities. LCPC method using CPT results was performed for comparing results of pile load test. Based on FOSM analysis using load factors, it is obtained that reliability indices for ultimate pile load capacity were higher than those of yield and allowable condition. Present safety factor 2 for yield and allowable load capacities is not enough to satisfy target reliability index $2.0{\sim}2.5$. However, it is sufficient for ultimate pile load capacity using safety factor 3.

• Journal of the Korean Wood Science and Technology
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• v.36 no.1
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• pp.69-78
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• 2008

Shearing strength test in tension type was investigated to determine the shear resistance of bolt and drift-pin connection of domestic larix glulam. The specimen was connected with bolt and drift-pin in the inserted plate type, and only bolt in the side plate type. The diameter of bolt and drift-pin used in the experiment are 12, 16 and 20 mm. The hole of bolt was drilled at the end-distance 5 d and 7 d. Tension load was loaded in the direction parallel to grain. The shear resistance was evaluated according to end-distance through this, the yield load was compared with the experimental yield load, using Larsen's formula. The prototype design strength is based on the yield load of end-distance 7 d and the reduction factor of end-distance 5 d was calculated. The results were as follows. 1. The average of maximum load of drift-pin connection was higher by 3~30% at the inserted type than at bolt connection with increasing diameter. In bolt connection, the average of maximum load of the side type was 1.54~2.07 times higher than that of the inserted type. In the same diameter, the average of maximum load of end-distance 7 d was higher by 8~44% than that of 5 d. 2. The bearing stress was 1.16~1.41 times higher at the inserted connection than at drift-pin connection, and 1.37~1.86 times higher at 7 d than at 5 d. Also, when the slenderness ratio was below 7.5 at drift-pin connection and below 6.0 at inserted connection, the lateral capacity was good. 3. The ratio of the experimental yield load and the predicted yield load calculated by Larsen's formula proposed by Larsen was 0.80~1.10 at inserted connection, and 0.75~1.46 at side connection. 4. When the inserted bolt connection was based on the yield load of end-distance 7 d, the reduction factor was 0.89 at 12 mm connection, 0.93 at 16 mm and 0.85 at 20 mm. The reduction factor was 0.89 at 12 mm the inserted drift-pin connection, 0.93 at 16 mm, 0.93 at 20 mm. The reduction factor was 0.79 at the side connection of the 12 mm bolt connection and 0.80 at 16 mm.

• Structural Engineering and Mechanics
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• v.6 no.4
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• pp.395-409
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• 1998

This paper concerns the development and implementation of an orthotropic, stress resultant elasto-plastic finite element model for the collapse load analysis of reinforced concrete plates. The model implements yield line plasticity theory for reinforced concrete. The behaviour of the yield functions are studied, and modifications introduced to ensure a robust finite element model of cases involving bending and twisting stress resultants ($M_x$, $M_y$, $M_{xy}$). Onset of plasticity is always governed by the general yield-line-model (YLM), but in some cases a switch to the stress resultant form of the von Mises function is used to ensure the proper evolution of plastic strains. Case studies are presented, involving isotropic and orthotropic plates, to assess the behaviour of the yield line approach. The YLM function is shown to perform extremely well, in predicting both the collapse loads and failure mechanisms.

• Structural Engineering and Mechanics
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• v.3 no.6
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• pp.529-539
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• 1995

The rigid-plastic yield-line analysis of isotropically reinforced concrete slabs acting in conjunction with torsionally weak supporting beams is developed as the lower-bound form of a linear programming formulation. The analysis is extended to consider geometric variation of chosen yield-line patterns by the technique of sequential linear programming. A strategy is followed of using a fine potential yield-line mesh to identify possible collapse modes, followed by analysis using a coarser, simplified mesh to refine the investigation and for use in conjunction with geometric optimization of the yield-line system. The method is shown to be effective for the analysis of three slabs of varying complexity. The modes detected by the fine and simplified analyses are not always similar but close agreement in load factors has been consistently obtained.

• Journal of Korea Water Resources Association
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• v.42 no.9
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• pp.737-745
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• 2009

Field measured sediment yield from an experimental urbanized basin was compared with the predicted sediment yields with RUSLE (Revised Universal Soil Loss Equation), and MUSLE (Modified Universal Soil Loss Equation). The experimental basin is 3.1km2 in area and fifty six percent of the total area had been urbanized. The hydrological data have been measured with T/M at the outlet of the experimental basin. Runoff from the basin and rainfall depth of the basin were measured every minute. Bed load and suspended load were also measured for a given flow rate. Runoff rating curves and sediment rating curve were developed for the last three years. RUSLE showed scattered prediction results but the average of the prediction values was close to the measured one. Meanwhile, MUSLE showed linear correlation between the measured sediment yield and predicted one with high correlation coefficient. But MUSLE predicts high values than the real one. Therefore, adjustment is necessary to apply MUSLE in estimation of sediment yield from the experimental urbanized basin.

• Horticulture, Environment, and Biotechnology : HEB
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• v.59 no.6
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• pp.815-826
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• 2018

The intense drought affecting olive production in Northern Chile underscores the need to research non-traditional irrigation strategies to obtain the best crop performance. Accordingly, this study aimed to obtain preliminary data to guide future research on this topic. Different water replenishment levels on crop evapotranspiration ($ET_c$ ; 13.5, 27.0, 40.5, and 54%) were established in a young orchard, cv. Arbequina, from the end of fruit drop (EFD) to full bloom in the next season. We evaluated the influence of plant water status (${\Psi}_{stem}$ ) and crop load, considered as function of fruit number divided by trunk cross-sectional area, on reproductive and productive variables using multiple linear regressions. Our results show that crop load and ${\Psi}_{stem}$ measured from EFD to harvest affected yield components. Nevertheless, ${\Psi}_{stem}$ had the strongest influence on fruit size, pulp development, oil accumulation, and yield. Oil content and yield were reduced by 54% and 50% for each MPa, respectively, from ${\Psi}_{stem\;EFD-H}$ -1.8 MPa, an effect that intensified as crop load increased. During the period of flower development (September-November), the number of flowers per inflorescence and percentage of perfect flowers were reduced when ${\Psi}_{stem}$ was less than -2.0 MPa. These preliminary results showed that bud differentiation, inflorescence and flower formation are highly sensitive to water deficit.

• Proceedings of the Safety Management and Science Conference
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• 2009.04a
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• pp.413-421
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• 2009

This paper investigates tensile characteristics of the stress aging heat-treated SM45C steel which are aging temperature at $250^{\circ}C$, $300^{\circ}C$, aging time at 1, 3 hours, and applied load at 300, 400N conditions by using acoustic emission. Most suitable aging condition was aging temperature $300^{\circ}C$, aging time 1 hour, and aging applied load 300N. And increased yield load 28.3% than non-treatment specimen in this condition. AE energy in elastic limit increased about 16.7 times than non-treatment specimen. When aging time is 3 hours, yield load decreased than other conditions that possibility is high to have itself defect on inside the specimen or coarse grain size precipitation is different in happened over-aging phenomenon. Especially, in case of $300^{\circ}C$, 3 hours and 400N condition appeared AE energy in elastic limit fairly high about 30 times than non-treatment specimen. This is considered by emit a lot of energies when material causes plastic deformation because the ductility increases on specimen by over-aging phenomenon.