• Title/Summary/Keyword: STORAGE

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A Study on the Heat-Storage/-Release Characteristics of a Regenerative Heat Exchanger Utilizing the Reversible Thermochemical Reaction of $Ca(OH)_2/CaO$ ($Ca(OH)_2/CaO$ 계의 가역 열화학 반응열을 이용한 축열식 열교환기의 축열 및 방열특성에 관한 연구)

  • Lee, Soo-Kag;Kim, Hong-Jea;Lee, Jin-Kook
    • Solar Energy
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    • v.9 no.2
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    • pp.22-30
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    • 1989
  • Since the energy storage method by means of the thermochemical reaction has no heat loss by separating the reactants under the storage period, it is remarked as one of promising means particularly for long-term heat storage. In this study, the heat-storage/-release characteristics of the reversible chemical reaction cycle, $Ca(OH)_2/CaO$, is numerically analysed by a mathematical modelling. As a result, the effectiveness of the heat exchanger by the chemical heat storage method is considerably higher than that by the sensible heat storage method. It is found that the major parameters, which determines the effectiveness of the heat exchanger, are the mass flow rate and inlet temperature of fluid, the residence time, etc.. The heat-storage/-release period can be controlled by changing the operation conditions. It is expected that the results obtained here will supply useful informations in designing a regenerative heat exchanger utilizing the thermochemical reaction.

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A Study on Transient Thermal Behavior During the Charging Process in a Stratified Water Storage Tank and Its Storage Efficiency (성층 온수 저장 중 과도 열거동과 축열효율에 관한 연구)

  • Pak, E.T.;Chu, Y.J.;Kim, Y.H.
    • Solar Energy
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    • v.17 no.3
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    • pp.13-21
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    • 1997
  • In this study, the theoretical equation of thermal storage efficiency was established to applied long term hot water storage system. The, effective thermal diffusivity and storage efficiency were, measured through the experiment to predict the degree of mixture in thermal storage tank. The effective thermal diffusivity was inversely preportional to the storage efficiency. The most effective storage efficiency was obtained under condition of low flow rate and using the perforated distributor.

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BoxBroker: A Policy-Driven Framework for Optimizing Storage Service Federation

  • Heinsen, Rene;Lopez, Cindy;Huh, Eui-Nam
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.1
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    • pp.340-367
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    • 2018
  • Storage services integration can be done for achieving high availability, improving data access performance and scalability while preventing vendor lock-in. However, multiple services environment management and interoperability have become a critical issue as a result of service architectures and communication interfaces heterogeneity. Storage federation model provides the integration of multiple heterogeneous and self-sufficient storage systems with a single control point and automated decision making about data distribution. In order to integrate diverse heterogeneous storage services into a single storage pool, we are proposing a storage service federation framework named BoxBroker. Moreover, an automated decision model based on a policy-driven data distribution algorithm and a service evaluation method is proposed enabling BoxBroker to make optimal decisions. Finally, a demonstration of our proposal capabilities is presented and discussed.

A Reliable Secure Storage Cloud and Data Migration Based on Erasure Code

  • Mugisha, Emmy;Zhang, Gongxuan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.1
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    • pp.436-453
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    • 2018
  • Storage cloud scheme, pushing data to the storage cloud poses much attention regarding data confidentiality. With encryption concept, data accessibility is limited because of encrypted data. To secure storage system with high access power is complicated due to dispersed storage environment. In this paper, we propose a hardware-based security scheme such that a secure dispersed storage system using erasure code is articulated. We designed a hardware-based security scheme with data encoding operations and migration capabilities. Using TPM (Trusted Platform Module), the data integrity and security is evaluated and achieved.

A Study on the Performance for the Cylindrical Packed Bed Sensible Heat Storage Unit (충진층 현열 축열조의 성태해소에 관한 연구)

  • Kwon, Sun-Seok;Kim, Si-Beom;Gu, Bon-Yeong
    • Journal of Ocean Engineering and Technology
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    • v.4 no.2
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    • pp.85-93
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    • 1990
  • A numerical study on the cylindrical packed bed sensible heat storage unit was accomplished by finite difference method. Relation between the heat storage rate and the mechanical pumping energy and the characteristics of the heat storage were investigated for various in let velocities and porosities. In this study, the numerical results are as follows: 1) The temperature distributions of solid and fluid rapidly reached the steady state as the heat capacity ratio was increased. 2) The efficiency of the heat storage was increased as the heat capacity ratio was decreased. For constant heat capacity ratio, however, the efficiency of the heat storage was increased at lower porosity. 3) It is very profitable to design the heat storage system such that the porosity is larger for the large flow rate and samller for small flow rate.

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A Study on the Performance for the Cylindrical Packed Bed Sensible Heat Storage Unit (충진층 현열 축열조의 성태해소에 관한 연구)

  • Kwon, Sun-Seok;Kim, Si-Beom;Gu, Bon-Yeong
    • Journal of Ocean Engineering and Technology
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    • v.4 no.2
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    • pp.235-235
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    • 1990
  • A numerical study on the cylindrical packed bed sensible heat storage unit was accomplished by finite difference method. Relation between the heat storage rate and the mechanical pumping energy and the characteristics of the heat storage were investigated for various in let velocities and porosities. In this study, the numerical results are as follows: 1) The temperature distributions of solid and fluid rapidly reached the steady state as the heat capacity ratio was increased. 2) The efficiency of the heat storage was increased as the heat capacity ratio was decreased. For constant heat capacity ratio, however, the efficiency of the heat storage was increased at lower porosity. 3) It is very profitable to design the heat storage system such that the porosity is larger for the large flow rate and samller for small flow rate.

An Exact Splitting Algorithm for a 4-Class-Based Dedicated Linear Storage Problem

  • Yang, Moon-Hee;Choi, Chang-Hwan;Kim, Hee
    • Management Science and Financial Engineering
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    • v.17 no.2
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    • pp.23-37
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    • 2011
  • In this paper, we address a layout design problem for determining an optimal 4-class-based dedicated linear storage layout in a class of unit load storage systems. Assuming that space requirement for a class is the sum of the maximum inventory levels of products assigned to the class, and that one-way travel time is a linear function of storage index, we formulate a 4-class-based dedicated linear storage problem PTL[4] and provide an exact splitting algorithm with $O(n{\lceil}logn{\rceil})$. Our algorithms could be applied to more than a 4-class-based dedicated storage layout problem with slight modification in order to reduce computational execution time.

Effect of Nitrogen Gas Enriched Packing on Quality and Storage Life of Pearl Millet Based Fried Snack

  • Ajita, Tiwari;Jha, S.K.
    • Journal of Biosystems Engineering
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    • v.42 no.1
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    • pp.62-68
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    • 2017
  • Purpose: The storage life of pearl millet-based, deep fried, ready-to-eat snacks, packaged in aluminum-laminated polyethylene having a thickness of $50{\mu}m$ (with and without nitrogen) was evaluated under storage conditions of $38{\pm}2^{\circ}C$ and 90% RH. Methods: The moisture content, free fatty acids (FFA), peroxide value, and crispness of the snack were evaluated throughout the storage period. The moisture content, FFA, and peroxide value increased with an increase in storage period, but the increase was less in packages flushed with nitrogen gas. The crispness decreased with an increase in the storage period, for snacks both with and without nitrogen packages. However, the decrease was less in nitrogen-flushed packages. FFA and peroxide values were strongly correlated with the moisture content of the snack. The storage life of the snack was found to be 60 and 45 days in packages with and without nitrogen respectively. Conclusions: The snack's predicted storage life, for snacks with and without nitrogen packages, was determined as 294 and 254 days respectively.

Probe Recording in Magnetic Patterned Media

  • Abelmann, Leon;Siekman, Martin;Murillo, Rogelio;Groenland, J.P.J. (Hans)
    • Transactions of the Society of Information Storage Systems
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    • v.3 no.2
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    • pp.86-93
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    • 2007
  • In this paper we explain why future probe storage systems will use patterned media. As a model system, magnetic patterned media will be discussed, even though their data density is limited to about $7Tbit/in^2$. The first results on magnetic probe storage on patterned media are presented, and the problem of switching field distribution is discussed in detail. Finally we will present the first steps into two-dimensional coding for patterned media.

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OWL Storage Model to Support Efficient Ontology Reasoning Query (효율적인 온톨로지 추론 질의를 지원하는 OWL 저장 모델)

  • Kim, Youn Hee;Lee, Ae Jung
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.7 no.3
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    • pp.25-35
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    • 2011
  • In the Semantic Web, storage models are required to efficiently store and retrieve metadata and ontology represented using OWL that can provide expressive power and reasoning support. In this paper, we propose an OWL storage model that can store and retrieve many restrictions and semantic relations defined on ontology with metadata. In addition, we propose some methods and rules to improve query processing efficiency of the proposed storage model. The proposed storage model can store and process large amounts of ontology and metadata because it consists of tables based on the relational database. And the proposed model can quickly provide more accurate results to users because of performing two different types of ontology reasoning and using the prime number labeling scheme to easily identify hierarchy relationships between classes or properties. The comparative evaluation results show that our storage model provides better performance than the existing storage model.