• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.23 no.2
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• pp.97-101
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• 2017

Fruits are subjected to a variety of vibration stress during the transportation from a production area to markets. Vibration inputs are transmitted from the transporting vehicle through the packaged fruit. And the steady state vibration input may cause serious internal damage of fruit. Product quality of fruits declines by various factors while they are stored right after harvesting and among the substance in charge of post ripening action, ethylene ($C_2H_4$) biosynthesis increases fruits' respiration process after harvesting and decreases storage expectancy. Ethylene production of apples rapidly increases while storage duration becomes longer. This tendency is much clearer for the apples with vibration stress at input acceleration level. When there was no vibration stress, change in ethylene production level of apples are not very large during storage. Ethylene production rates inside the gas collecting container increased significantly ($p{\leq}0.05$) after 24 hours storage, particularly for apples with vibration stress ($0.7{\mu}l/kg{\cdot}hr$ (1st stack), $0.78{\mu}l/kg{\cdot}hr$ (2nd stack), $0.96{\mu}l/kg{\cdot}hr$ (3rd stack)); whereas less ethylene was produced in control apples ($0.18{\mu}l/kg{\cdot}hr$ during storage. Also ethylene production rates of apples according to the stack position were significantly different ($p{\leq}0.05$). The vibration stress clearly accelerated the degradation of apple quality during storage, resulting in increased ethylene production.

• Smart Media Journal
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• v.6 no.1
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• pp.9-15
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• 2017

The trends in ICT are concentrated in IoT, Bigdata, and Cloud Computing. These mega-trends do not operate independently, and mass storage technology is essential as large computing technology is needed in the background to support them. In order to evaluate the performance of high-capacity storage based on open source Ceph, we carry out the demonstration test of Abyss Storage with domestic and overseas sites using educational network KOREN. In addition, storage media and network bonding are tested to evaluate the performance of the storage itself. Although there is a substantial difference in aspect of the physical speed among storage medias, there is no significant performance difference in the storage media test performed. As a solution to this problem, we could get performance improvement through network acceleration. In addition, we conducted actual performance test of Abyss Storage internal and external network by connecting domestic and overseas sites using KOREN network.

• Journal of Electrical Engineering and Technology
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• v.13 no.5
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• pp.1965-1977
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• 2018

This paper proposed a regenerative braking system (RBS) strategy for battery electric vehicles (BEVs) with a hybrid energy storage system (HESS) driven by a brushless DC (BLDC) motor. In the regenerative braking mode of BEV, the BLDC motor works as a generator. Consequently, the DC-link voltage is boosted and regenerative braking energy is transferred to a battery and/or ultracapacitor (UC) using a suitable switching pattern of the three-phase inverter. The energy stored in the HESS through reverse current flow can be exploited to improve acceleration and maintain the batteries from frequent deep discharging during high power mode. In addition, the artificial neural network (ANN)-based RBS control mechanism was utilized to optimize the switching scheme of the vehicular breaking force distribution. Furthermore, constant torque braking can be regulated using a PI controller. Different simulation and experiments were implemented and carried out to verify the performance of the proposed RBS strategy. The UC/battery RBS also contributed to improved vehicle acceleration and extended range BEVs.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.11 no.1
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• pp.17-24
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• 2005

During handling unitized products, they are subjected to a variety environmental hazards. Shock and vibration hazards are generally considered the most damaging of the environmental hazards on a product, and it may encounter while passing through the distribution environment. A major cause of shock damage to products is drops during manual handling. The increasing use of unitization on pallets has been resulted in a reduction in the manual handling of products and with it a reduction in the shock hazards. This has caused and increasing interest in research focused on vibration caused damage. the use of pallets as a base for unitizing loads, aids in the mechanical handling, transportation and storage of products. Besides aiding in the handling, transportation and storage of products, a pallet also acts on and interface between the packaged goods and the distribution environment. The determination of the impact deformation of the cushioning materials such as tray cup (polymeric foam) and corrugated fiberboard pad must be carried out to design the proper packaging system providing adequate protection for the fruit, and to understand the complex interaction between the components of fruit when they relate to expected transportation vibration inputs. In this study, the theoretical analysis of impact deformation for cushioning materials by dynamic vibration. The impact deformations of SW and DW corrugated fiberboard pad in acceleration amplitudes of 0.25 G-rms and 0.5 G-rms that were usually generated in transport vehicles during distribution environments were very small compare with the thickness of corrugated fiberboard pad. The maximum of vibration acceleration level of tray cup by vibration impact was about 3.2 G-rms. The theoretical allowable acceleration (G-factor) of the pear was 0.7102 G-rms, and the maximum dynamic deformation estimated within G-factor was about 1 mm.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.6
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• pp.1047-1052
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• 1998

The effects of antioxidants such as ascorbyl palmitate(AP), tocopherol( Toc), BHA and ascorbyl palmitate＋ tocopherol(AP＋ Toc) on lipid peroxide formations in lard have been investigated during storage at 50oC after gamma irradiation with the dose of 1~10kGy. Immediately gamma irradiation greatly increased the initiative oxidation of lard as expected. But antioxidants were found to be greatly effective in minimizing the radiation induced peroxidation of lard. The decreasing order of effects on their antioxidative activities was AP>AP＋ Toc>BHA> Toc. Oxidation of lard during storage at 50oC after irradiation induced the acceleration of autooxidation. But the additions of an tioxidants inhibited the formation of peroxides. Their antioxidative activities during storage were BHA> AP＋ Toc> Toc>AP. Especially AP＋ Toc mixture was not significantly different from BHA (p>0.05).

• 정보저장시스템학회:학술대회논문집
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• 2005.10a
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• pp.195-196
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• 2005

We report the new design of a miniature electromagnetic actuator for probe-based data storage with anti-vibration mechanism. The actuator consists of a media substrate, silicon frame, 2 pairs of magnets, a spacer, and a printed circuit board (PCB). The total area of the device is $11.2{\times}11.2 mm^2$ while the data recording area is $7.4{\times}7.4 mm^2$. A net momentum fee structure was included for high vibration resistance. The simulation shows that the lateral vibration can be reduced to below 100 nm for 1 G acceleration if the counter mass is adjusted with $1\%$ difference. The peak power for ${\pm}50 {\mu}m$ displacement is below 50 mW for a actuator with a resonance at 200 Hz.

• Structural Engineering and Mechanics
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• v.52 no.5
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• pp.875-887
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• 2014

The aim of the shaking table experiment is to verify the isolation effect of a storage liquid tank with multiple friction pendulum bearings. A 1:20 scale model of a real storage liquid tank that is widely used in the petroleum industry was examined by the shaking table test to compare its anchored base and isolated base. The seismic response of the tank was assessed by employing the time history input. The base acceleration, wave height and tank wall stress were used to evaluate the isolation effect. Finally, the influences of the bearing performance that characterizes the isolated tank, such as the friction force and residual displacement, were discussed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.3
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• pp.544-551
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• 2011

This paper presents the circuit arrangement and effective control method of regenerative energy storage system for an electric vehicle using super-capacitors as the braking energy storage element. A bi-directional controlled current flow of the DC-DC converters with the capacitor bank is connected in parallel with battery, and is controlled so that the whole of the braking energy is effectively absorbed into the capacitors and released back to the electric motor upon acceleration. The converter needs the series-parallel switching circuit for making the best use of the series capacitors and for limiting the step-up ratio of the boost converter. The proposed methods are verified by computer simulation and experimental set-up. They are usefully applied to the electric vehicles such as green cars, electric motorcycles, bike, etc which are power- supplied by the electric batteries.

• Nuclear Engineering and Technology
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• v.54 no.4
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• pp.1355-1362
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• 2022

Nuclear fuel, including its fresh state, must be handled safely due to its critical and hazardous nature. Under normal transport conditions, several interactions take place among different components, such as transport cask used for loading the nuclear fuel and tie-down structure to attach with the vehicle. To ensure structural integrity of the nuclear fuel, vibrations and impacts transmitted from the vehicle must be sufficiently reduced. Therefore, in this study, we conducted two transportation tests from Daejeon to Kijang in Korea to verify the vehicle-induced vibrational characteristics of the KJRR-F fresh nuclear fuel when transported under normal transport conditions. The speed and location of the vehicle were obtained via GPS, and the accelerations between the vehicle and the KJRR-F fresh nuclear fuel were measured. Additionally, using the acceleration results, a structural analysis was conducted to confirm the structural integrity of the nuclear fuel under the most severe conditions during normal transport.

• Korean Journal of Food Science and Technology
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• v.39 no.4
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• pp.425-431
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• 2007

The quality characteristics of Gangjung added with detoxified Rhus verniciflua stem bark (RVSB) extract, as well as the changes that occurred in the product during accelerated storage ($60^{\circ}C$, 24 hr), were investigated. The expansion rate of Gangjung was not significantly different (p < 0.05). The L-value of the Gangjung with added detoxified RVSB extract was higher than the control, while the a-value decreased as the addition levels of the detoxified RVSB extract increased. The b-value was highest for the Gangjung prepared with 7% (w/w) detoxified RVSB extract. The moisture content of the Gangjung decreased as the storage period increased, but the addition of detoxified RVSB extract (p < 0.05) did not significantly change this effect. We found no significant difference in the hardness of the Gangjung within the concentration range of 0-7% (w/w) detoxified RVSB extract, and the peak number slightly decreased as the storage period increased. After 16 hr of storage, the acid value was significantly lower for the Gangjung containing detoxified RVSB extract at concentration between 5-7%. Furthermore, after 12 hr of accelerated storage, peroxide and TBA values significantly decreased with additions of detoxified RVSB extract that were over 3% (w/w). These results suggest that the physical texture of Gangjung did not improve by the addition of detoxified RVSB extract; however, its rate of lipid oxidation was reduced.