• Journal of the Korean institute of surface engineering
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• v.35 no.4
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• pp.206-210
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• 2002

The use of Spectra fibers as fiber cloth is increasing because of their excellent impact resistance. However, a major limitation on the use of Spectra fibers is a chemical inertness. In this Study, Spectra fibers were surface-treated using Ar$^{+}$ ion beam under oxygen environment to improve the tensile property of Spectra/vinylester composites. The effect of surface treatment of Spectra fibers on the tensile property of Spectra/vinylester composites was determined from tensile tests using Spectra/vinylester composite specimens with and without a hole. It was found that the tensile stiffness and strength of surface-treated case were 22% and 17% higher than those of untreated case for specimens with no hole. The maximum load of surface-treated case was about 15% higher than that of untreated case for specimens with a hole.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.3
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• pp.374-379
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• 2017

In vehicle to pedestrian accidents, cracks occur in the vehicle laminated glass due to impact of a pedestrian's head. In this study, FMH(Free Motion Headform) was used to experiment on and analyze the crack patterns on a vehicle laminated glass that collides with an adult headform at speeds of 20 km/h, 30 km/h, and 40 km/h, respectively. Applying the acquired experimental data and material property of the vehicle laminated glass to the structural analysis program LS-Dyna, we could develop the FE model of vehicle laminated glass similar to real vehicle laminated glass. We could estimate the head impact velocity and pedestrian's vehicle impact velocity using the Madymo program.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.5
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• pp.390-398
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• 2014

Heavy-weight floor impact noise is directly related to the impact source and floor vibration property. Dynamic properties of the standard floating floor that is used in Korea was investigated using accelerance, acceleration energy spectral density(ESD), and structural modal test. In the standard floating floor, natural frequency was decreased by the finishing mortar mass and the damping ratio was increased. Bang-machine force spectrum acting on the concrete slab can be calculated using inverse system analysis. Impact force acting on concrete slab is changed by interaction of finishing mortar and resilient material. The amplitude of the bang-machine force spectrum was amplified in low frequency range(below 100 Hz), and over 100 Hz was decreased. Changed force spectrum influence to the response of structure vibration, so the heavy-weight floor impact noise level was changed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.10a
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• pp.89-90
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• 2010

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2001.11a
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• pp.26-27
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• 2001

• 한국기계연구소 소보
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• s.11
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• pp.39-46
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• 1984

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.4
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• pp.787-793
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• 2002

In this study, a bar impact test of low velocity was carried out to gain an insight into the damage mechanism and sequence induced in alumina plates(AD 85 and AD 90) under impact conditions. An experimental setup utilizing an instrumented long bar impact was devised, that can measure directly the impact force applied to the specimen and supply a compressive contact pressure to the specimen. During the bar impact testing, the influences of the contact pressure applied along the impact direction to the specimen on the fracture behavior were investigated. The measured impact force profiles explained well the damage behavior induced in alumina plates. The higher contact pressure to the specimen led to the less damage due to the suppression of radial cracks due to the increase in the apparent flexural stiffness of plate. It had produced the change of damage pattern developed in the specimen; from the radial cracks to the local contact stress dominant damage. It would contribute to the improvement of the ballistic property in ceramic plates. The observed results showed the following sequence in damage developed: The development of cone crack at impact region, the formation of radial cracks from the rear surface of plate depending on the plate thickness, the occurrence of crushing within the cone envelope and the fragmentation.

• Journal of Korea Foundry Society
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• v.35 no.6
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• pp.163-169
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• 2015

This study reports the influence of gadolinium (Gd) addition on mechanical and corrosion properties of 2205 duplex stainless steel. In all alloys produced, regardless of the initial Gd content, Gd-based inclusions were well distributed in the duplex stainless steel matrix. As the Gd content increased from 0 wt% to 0.19 wt%, the ultimate tensile strength and hardness of the alloy increased from 630 MPa to 977 MPa and from 57 to 61, respectively, while elastic modulus, tensile elongation and impact energy of the alloy decreased. The critical crevice temperatures of Alloy1, Alloy2 and Alloy3 were $20^{\circ}C$, $20^{\circ}C$ and $15^{\circ}C$, respectively.

• Journal of Digital Convergence
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• v.11 no.10
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• pp.79-94
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• 2013

Perceived value of the property and determine the satisfaction and accommodation factors impact factor in customer satisfaction, and perceived value of factors for the tourists and the the satisfaction degree of freezing gareul analysis in the following results are derived. First, the economics of accommodation, convenience to the tourists, but the perceived value and accessibility and facilities that do not affect the show better, second, the perceived value, affordability, amenities, increase tourists' satisfaction showed.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.3
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• pp.469-477
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• 2021

In this paper, the relationship between the profitability level of an enterprise and the credit policy adopted by an enterprise was measured. A sample of industrial firms listed on the stock exchanges of Iraq, Jordan, and Kuwait was analyzed. Five industrial firms were randomly selected from each exchange with a condition of having at least 5 year-activity. The total sample size was 15 industrial firms. The study financial data was imported from the sample firms' websites. The financial data was for the financial year 2017. The Regression Analysis was adopted to measure the impact of trade credit on the profitability of an enterprise using the SPSS software. It was found that the receivable accounts have a proportional relationship with the turnover property rights rate. Similarly, the statistical results showed that the turnover property rights rate increased with an increase in the turnover receivable accounts rate and the percentage of investment in receivable accounts. The influence of trade credit on the enterprise profitability percentage in the Iraq stock exchange, Amman stock exchange, and Boursa Kuwait were 0.938, 0.200, and 0.089, respectively. The results showed that the three secondary assumptions were incorrect, while the zeroth assumption, i.e., trade credit has no influence on profitability, was correct.