• Textile Coloration and Finishing
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• v.27 no.2
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• pp.132-141
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• 2015

Fall-arrest systems(maximum arrest force and allowable free-fall) have been widely applied to provide a safe stop during fall incidents for various industrial activities. Fabric structure affects on the mechanical properties of shock energy absorber. The object of this study is to perform the basic research for the evaluation of the capacity of fall arrest energy absorber in relation to the different interlace yarn density. In this work, pack style energy absorber was prepared by weaving 10 types(Interlace yarn density used high tenacity PET 1000D : 60, 59, 58, 57, 56, 55, 54, 53, 52, 51). The paper presents the results of theoretical investigations of the performance of adjustable absorber during fall arrest. Dynamic load tests based on the EU fall protection equipment standard(CE : EN355:2002) were conducted. Results showed that the maximum arrest force by dynamic load test of energy absorber was satisfied with global standard(below 6,000N). Also, Maximum allowable free-fall of energy absorber showed below 1.75m.

• Geomechanics and Engineering
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• v.10 no.2
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• pp.155-174
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• 2016

A total of 104 laboratory model tests on a square footing subjected to eccentrically inclined loads supported by sand reinforced with randomly distributed polypropylene fibers were conducted in order to compare the results with those obtained from unreinforced sand and with each other. For conducting the model tests, uniform sand was compacted in a test box at one particular relative density of compaction. The effect of percentage of reinforcement used, thickness of the reinforced layer, angle of inclination of load to vertical and eccentricity of load applied on various prominent factors such as ultimate load, vertical settlement, horizontal deformation and tilt were investigated. An improvement in ultimate load, vertical settlement, horizontal deformation and tilt of foundation was observed with an increase in the percentage of fibers used and thickness of reinforced sand layer under different inclinations and eccentricities of load. A statistical model using non-linear regression analysis based on present experimental data for predicting the vertical settlement ($s_p$), horizontal deformation ($hd_p$) and tilt ($t_p$) of square footing on reinforced sand at any load applied was done where the dependent variable was predicted settlement ($s_p$), horizontal deformation ($hd_p$) and tilt ($t_p$) respectively.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.1024-1029
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• 1998

In this paper, the voltage-fed series compensated inductor type load-resonant high-frequency inverter is originally presented for driving a newly-developed silent discharge ozone generating tube. The effective power regulation scheme of this ozonizer is proposed, which is based on PDM (Pulse Density Modulation) related PWM strategy due to DSP implementation. The effectiveness of this inverter type ozonizer is proved in simulation and experiment.

• International Journal of Automotive Technology
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• v.6 no.4
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• pp.421-427
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• 2005

This work analyzes the behaviors of aerated lubricant in the gap between con-rod bearing and journal. It is assumed that the film formation with aerated lubricant is influenced by the two major factors. One is the density characteristics of the lubricant due to the volume change of lubricant for the formation of bubbles and the other is the viscosity characteristics of the lubricant due to the surface tension of the bubble in the lubricant. These two major factors surprisingly increase the load capacity in some ranges of bubble sizes and densities. Modified Reynolds' equation is developed for the computation of fluid film pressure with the effects of aeration ratio in the lubricant. From the calculated load capacity by solving modified Reynolds' equation, journal locus is computed with Mobility method after comparing it with the applied load at each time step. The differences of journal orbits between aerated and pure lubricants are shown in the computed results.

• Current Photovoltaic Research
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• v.4 no.2
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• pp.48-53
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• 2016

We report the effect of physical load on the stability of organic solar cells under physical loads. The active layers in organic solar cells were fabricated with bulk heterojunction films (BHJ) films of poly (3-hexylthiophene) and phenyl-$C_{61}$-butyric methyl ester. The loading time was varied up to 60 s by keeping the physical load constant. Results showed that the open circuit voltage was not influenced by the physical load but other solar cell parameters were sensitive to the loading time. The fill factor was very slightly increased at 15 s, while short circuit current density was well kept for 30 s. The power conversion efficiency was reasonably maintained for 45 s but became significantly decreased by the continuous loading for 60 s.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.6
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• pp.282-289
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• 2001

This paper introduces the scheme that improve the control performance of electromagnetic levitation system with zero power controller. Magnetic levitation is used widely, but the electromagnetic force has nonlinear characteristics because it is proportioned to a square of the magnetic flux density and it is in inverse proportion to a square of the airgap. So, it is complicate and difficult to control the electromagnetic force. Besides, it is more difficult to control if the equivalent gap is unknown in case of zero power control. Therefore, this paper proposed the hybrid electro-magnetic levitation control method in which the variable load is estimated by using a load observer and its system controlled at a new zero power equilibrium airgap position. Also it is confirmed that the proposed control method improve the control performance through simulation and experiment.

• Journal of the Korea Furniture Society
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• v.19 no.5
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• pp.350-357
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• 2008

This research investigates the bending properties to predict the work-energy to maximum load and impact bending energy from static bending and impact bending test. Specimens were prepared from lumber made of thinning crop-trees. Matched specimens were used for MC 12% and green moisture specimens to measure the effect of moisture content on the absorbed energy from static and impact bending tests. The bending properties such as MOE, MOR, etc. is a good predictor to investigate the work-energy and work-energy per unit volume from static bending and impact bending test. The impact bending energy is increased with increasing moisture content. However, the work to maximum load from static bending test is increasing with increasing the MC only for higher density species.

• Computers and Concrete
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• v.12 no.1
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• pp.37-51
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• 2013

The responses of reinforced concrete slabs subject to an impact loading near the ultimate load range are explored. The analysis is carried out on a simply supported rectangular reinforced concrete slab using a nonlinear explicit dynamic procedure and considering three material models: Drucker-Prager, modified Drucker-Prager, and concrete damaged plasticity, available in the commercial finite element software, ABAQUS/Explicit. For comparison purposes, the impact force-time response, steel reinforcement failure, and concrete perforation pattern are verified against the existing experimental results. Also, the effectiveness of mesh density and damage wave propagation are studied independently. It is shown that the presently adopted finite element procedure is able to simulate and predict fairly accurate the behavior of reinforced concrete slab under impact load. More detailed investigations are however demanded for the justification of effects coming from an imperfect projectile orientation as well as the load and structural surface conditions, including the impulsive contacted state, which are inevitable in an actual impact environment.

• Journal of Korean Society on Water Environment
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• v.28 no.6
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• pp.786-795
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• 2012

Water quality management should be focused on the pollution concentrated area so that the improvement of water quality can be achieved effectively for the management of Total Maximum Daily Loads (TMDLs). It is necessary to consider discharge characteristics in the TMDL plan. This study analysed discharge characteristics such as pollution generation and discharge load density, and reduction potential by each unit watershed, and categorized the unit watershed into four groups according to its discharge load characteristics. This analysis can be used as helpful information for the prioritization of pollution reduction area and selection of pollution reduction measures in the development of TMDL plans.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.413-418
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• 2004

Recently, the development of mobile devices demands information storage systems to use micro drive devices. 1-inch micro drive hard disk uses the load/unload(L/UL) technology to increase area recording density and reduce power consumption. Because micro drive has light actuator, effects of the flexible cable that is ignored in 3.5-inch hard disk drive is important to load/unload performances. In this paper, effects of flexible cable on load/unload performances are studied.