• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.192.1-192
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• 2003

The aim of this study was to develop a model that could be used in the design of modified atmosphere packaging (MAP) for Mandarin oranges. Respiratory data at 5, 10, 20$^{\circ}C$ for mandarin oranges were gathered and altered for create useful respiration model. The maximum rate of oxygen uptake increased with increasing temperature. The packaging materials were conventional low density polyethylene and polypropylene with anti-fog, and anti-fungi treatments, and thickness was 30 $\mu\textrm{m}$ and 50 $\mu\textrm{m}$. Permeability tests were performed to find their oxygen, carbon dioxide, water vapor transmission rate as increases in temperature. Test results were then converted to logarithm format for MAP modeling. Optimum gas composition in the package system for fruits were set according to literature and upper or lower limits of oxygen and dioxide established. To predict gas composition at certain storage time, weight of fruits, film thickness, film type, and other variables, respiration rate was studied at various storage conditions. The validity of the model was tested experimentally by observing actual atmospheric changes inside packages. It is concluded that the strategy developed is of use in designing dynamic gas exchange MAP systems, and also has potential uses in similar agricultural products.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.685-688
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• 2006

A single-phase uninterruptible power supply system suitable for a SMES unit is proposed to achieve a simple circuit configuration and higher system reliability. It reduces the number of switching devices by applying a common-arm scheme. Operational principles to normal, stored-energy, and bypass mode are discussed in detail. Eliminating some of the switches or substituting passive components for active switches generally increases the sophistication and reduces degree of freedom in control strategy. However, the high-performance digital controller ran execute the complicated control task with no additional cost. The validity of the proposed UPS system will be verified by a computer-aided simulation.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.2
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• pp.223-230
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• 2009

Most urban water management systems are becoming vulnerable to flooding and drought due to the climate change (CC), urbanization and energy shortage. Despite of poor water management circumstances caused by extremely uneven annual rainfall and hilly terrain, traditionally we have made a sound and sustainable life based on our own philosophy and technologies which copes with our rigid environment. In this study a new paradigm of rainwater management is suggested and multipurpose and creative rainwater harvesting and management (RWHM) systems are introduced providing several case studies such as rainfall storage drainage (RSD) system, rainwater infiltration facilities and star city RWHM system. This new RWHM paradigm leads Seoul Metropolitan Government (SMG) in the Republic of Korea to change regulations and politics for the integrated RWHM. Finally, RWHM is expected to improve the safety, efficiency, energy consumption of urban water infrastructure, to reduce urban heat island phenomenon and, furthermore, to contribute in finding solutions for worldwide water issues and to adapt CC.

• Journal of the Korean Solar Energy Society
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• v.35 no.3
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• pp.57-63
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• 2015

This paper presents a solution by introducing energy storage system(ESS) to solve an annual blackout due to a typhoon or electrical failure in Udo Island. This island is now receiving electrical power through undersea cables from the Jeju Island. During blackout period, ESS will supply the electricity. And it is necessary to estimate the ESS capacity and control the transient state for the operation of stable power system. For the verification of proposed method, ESS capacities have been estimated according to base load and the minimum capacity of only home appliance in Udo Island. Also, in case of restoring from the fault, the algorithm for synchronization is proposed. Finally, the simulation results by using the PSCAD/EMTDC program will show the feasibility.

• Current Applied Physics
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• v.18 no.12
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• pp.1507-1512
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• 2018

The development of an organic-based aqueous redox flow battery (RFB) using quinone as an electroactive material has attracted great attention recently. This is because this battery is inexpensive, produces high energy density, and is environment friendly in stationary electrical energy storage applications. Herein, we investigate the redox potentials and solubilities of indole-5,6-quinone and indole-4,7-quinone derivatives in terms of the substituent effects of functional groups using theoretical calculations. Our results indicate that full-site substituted derivatives of indolequinone are more useful as active materials compared to single-site substituted derivatives. In particular, our calculations reveal that the substitution of $-PO_3H_2$ and $-SO_3H$ functional groups with multiple polar bonds is very effective in increasing the activity of the aqueous RFB. As a strategy to overcome the limitation that the aqueous solubility is intrinsically low because they are organic molecules, we suggest the substitution of functional groups with multiple polar bonds to the backbones of active organic materials. Among 180 indolequinone derivatives, 17 candidates that meet the redox potential standards ($${\leq_-}0.2V$$ or $${\geq_-}0.9V$$) and eight candidates with solubility exceeding 2 mol/L are identified. Three indolequinone derivatives that satisfy both conditions are finally presented as promising electroactive candidates for an aqueous RFB.

• Smart Structures and Systems
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• v.29 no.3
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• pp.457-473
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• 2022

A high-frequency vibration control method is proposed in this paper for Pumped Storage Power Plants (PSPPs) using Eddy Current Tuned Mass Damper (EC-TMD), based on which a new type of EC-TMD device is designed. The eddy current damper parameters are optimized by numerical simulation. On this basis, physical simulation model tests are conducted to compare and study the effect of structural performance with and without damping, different control strategies, and different arrangement positions of TMD. The test results show that EC-TMD can effectively reduce the control effect under high-frequency vibration of the plant structure, and after the additional damping device forms EC-TMD, the energy dissipation is further realized due to the intervention of eddy current damping, and the control effect is subsequently improved. The Multi-Tuned Mass Damper (MTMD) control strategy broadens the tuning band to improve the robustness of the system, and the vibration advantage is more obvious. Also, some suggestions are made for the placement of the dampers to promote their application.

• Journal of Electrochemical Science and Technology
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• v.13 no.3
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• pp.398-406
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• 2022

To satisfy the growing demand for high-performance batteries, diverse novel anode materials with high specific capacities have been developed to replace commercial graphite. Among them, cobalt hydroxides have received considerable attention as promising anode materials for lithium-ion batteries as they exhibit a high reversible capacity owing to the additional reaction of LiOH, followed by conversion reaction. In this study, we introduced graphene in the fabrication of Co(OH)₂-based anode materials to further improve electrochemical performance. The resultant Co(OH)₂/graphene composite exhibited a larger reversible capacity of ~1090 mAh g^-1, compared with ~705 mAh g^-1 for bare Co(OH)₂. Synchrotron-based analyses were conducted to explore the beneficial effects of graphene on the composite material. The experimental results demonstrate that introducing graphene into Co(OH)₂ facilitates both the conversion and reaction of the LiOH phase and provides additional lithium storage sites. In addition to insights into how the electrochemical performance of composite materials can be improved, this study also provides an effective strategy for designing composite materials.

• International Journal of Computer Science & Network Security
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• v.24 no.5
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• pp.95-102
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• 2024

In distributed computing, accessible encryption strategy over Auditable data is a hot research field. Be that as it may, most existing system on encoded look and auditable over outsourced cloud information and disregard customized seek goal. Distributed storage space get to manage is imperative for the security of given information, where information security is executed just for the encoded content. It is a smaller amount secure in light of the fact that the Intruder has been endeavored to separate the scrambled records or Information. To determine this issue we have actualize (CBC) figure piece fastening. It is tied in with adding XOR each plaintext piece to the figure content square that was already delivered. We propose a novel heterogeneous structure to evaluate the issue of single-point execution bottleneck and give a more proficient access control plot with a reviewing component. In the interim, in our plan, a CA (Central Authority) is acquainted with create mystery keys for authenticity confirmed clients. Not at all like other multi specialist get to control plots, each of the experts in our plan deals with the entire trait set independently. Keywords: Cloud storage, Access control, Auditing, CBC.

• Fire Science and Engineering
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• v.30 no.6
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• pp.48-56
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• 2016

A crude oil leakage from a large atmospheric storage tank occurred on 4 April 2014 at 14:50 in Ulsan City, while storing the crude oil in the tank. Emergency Rescue Control Group was deployed in the scene. The company, Fire Service Headquarters and associated agencies got together in Command Post (CP) for discussing an effective corresponding strategy. Many solution plans were drafted in the debate such as power down, stopping the facilities, checking the density of inflammable gas, suppressing oil evaporation, moving the leaked crude oil to a nearby tank and a processing plant and avoiding marine pollution. All the solutions were carried out in cooperation with several agencies and partners. The oil leakage accident was successfully settled up within the process of responding, The Fire Service Headquarters and the company thought that the most important thing was the suppression of oil evaporation and the elimination of ignition source. With Fire Service Headquarters and several agencies' every effort, an explosion and a fire didn't occurred in the scene. This study suggest the improvement of the operating system in Emergency Rescue Control Group in case of petroleum leakage, explosion and fire accidents of atmospheric storage tank, different from a ordinary disaster. Assuming that petroleum leakage in atmospheric storage tank develop the explosion and fire accidents, the spreading speed of the flame and the burning time was experimented and compared with each other. Furthermore, this study concentrates on the effective field response plan prepared for the afterward explosion and fire accidents from petroleum leak in a storage tank, with the database experimented and analyzed in accordance with the angle of radiation in the foam nozzle and the pressure of pumping in a fire engine.

• Journal of the Korean Graphic Arts Communication Society
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• v.30 no.3
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• pp.23-33
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• 2012

We studied simultaneously the electronically written data affected in the use of thermal transfer discs and the recoding strategy between recoding drives for the stable long term preservation of optical discs which are commonly used in an electronic data storage device. The most important thing in the archiving preservation might be a choice of a device, however the use of thermal transfer recording discs is not good for long term data preservation because the thermal effect on the recoding data is critical which means that the data are recorded not under best condition but under bad condition. We inspect the strategies of recoding data from 12 brands of optical discs and drives of 7 brands and it turns out the recoding strategy is needed first for the long term preservation of electronic recording data. Thus, without affecting data quality and deformation of optical discs, the choice of optimal disc and drive in recoding data will be a solution for the long term preservation of recoding data.