• Title/Summary/Keyword: Time of storage

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A Study on the Development of Battery Energy Storage System (전지이용 전력저장장치 기술개발)

  • Hwang, Yong-Ha;Lee, Keun-Seob
    • Proceedings of the KIEE Conference
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    • 1993.07b
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    • pp.905-907
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    • 1993
  • Demand for electricity is increasing annually. Especially, the daytime demand grawth shows higher than any other time period. So the big difference between maximum and minimum electrical demand becomes another important problem to be solved. The Battery Energy Storage System is chosen as one of the solutions among the sevral methods. The purpose of utilization of Battery Energy Storage System is to improve the daily load factor. Also, Battery Energy Storage System may be used for the load levelling or the load shifting as well as the spinning reserve. Up to now, only the pumped hydro power plant system has been operated on the commercial basis, but this system has so many constraints such as site, environmental effects, construction period, ect. Being considered current electrical power situation the development of electric storage system is in need latly. Among the various electric storage systems, Battery Energy System is chosen with the top priority because it has sevral merits to cover such as the short construction period, the demand site installation, and the food environmental characteristics.

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Changes in Isothiocyanate Levels in Korean Chinese Cabbage Leaves during Kimchi Storage

  • Hong, Eun-Young;Kim, Gun-Hee
    • Food Science and Biotechnology
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    • v.15 no.5
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    • pp.688-693
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    • 2006
  • Glucosinolates are hydrolyzed by the enzyme myrosinase and are mainly found in cruciferous vegetables such as Chinese cabbage (Brassica campestris L. ssp. pekinensis). lsothiocyanates (ITCs) are glucosinolate degradation products with reported anticarcinogenic properties. Korean Chinese cabbage in the form of 'kimchi' is a staple part of the Korean diet. In this study, we examined the effects of storage temperature and duration on glucosinolate, ITC, soluble sugar, and organic acid levels in kimchi. Changes in pH and the impact of various parts of the Korean Chinese cabbage being used during the preparation of the dish were also assessed. Extracted ITC levels, analyzed via gas chromatography (GC) and GC/mass spectrometry (GC/MS), were higher in the midrib parts than in the cabbage leaves after storage at both 4 and $20^{\circ}C$. During storage, organic acid levels increased while soluble sugars were depleted. The pH initially increased (after 1 day at $20^{\circ}C$, and 1 week at $4^{\circ}C$), but subsequently decreased over time at both temperatures. Glucosinolate and ITC levels increased in the beginning of storage but then generally fell during further storage. Our data suggest that acidity-related reduction in myrosinase activity during storage may decrease glucosinolate and ITC levels. The changes in these levels depended on the storage conditions and the Korean Chinese cabbage parts used for the kimchi preparation.

A Study on the Improvement of Storage Environment in Museums -With Research on Actual State of Storage in Domestic Museums- (박물관 수장부문의 환경개선에 관한 연구 -국내 박물관 수장고 실태조사를 중심으로-)

  • 임채진;정성욱
    • Korean Institute of Interior Design Journal
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    • no.25
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    • pp.253-261
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    • 2000
  • Except the time when the relics of the museum are exhibited or loaned to the public, they are stored in a storage. Therefore, the environmental condition of a storage is a important factor. But in Korea, the appearance of the building and exhibition design are emphasized more than any other factors in planing museums, so the preservation technology has not yet reached the appropriate level and leaded to some environmental problem in the museum storage. The purpose of this study is to suggest guideline for an apt storage system by reconsidering practical notes in planning storage and give a efficient long-term plans examinable category. So this study based on the research had been stated from the recognition that the relics should be planned and placed differently in sorts, and developed this by researching the theory related to the matter throughout documents and to cope with the low efficiency in its essential role compared to the massive investment and through on-the-spot surveys emphasizing on the storage of the domestic museums in progress since 1995. Hereafter it compares the actual condition and problems of the domestic museum planning with the ones abroad, and analyzes the characteristic and difference between the two, and then establish an organized storage system.

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A STUDY OH THE ECONOMIC OPERATION OF SMES FOR ENERGY STORAGE (전력 저장용 SEMS의 경제적 운용에 관한 연구)

  • Roh, Hee-Ho;Hahn, Song-Yop;Rhee, Sung-Won
    • Proceedings of the KIEE Conference
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    • 1988.11a
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    • pp.13-16
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    • 1988
  • As the automic power plant is increased, load leveling energy storage system becomes more important. Pumped hydroelectric storage, used in the present, has too storage efficiency and difficulty in selecting site. But SMES(Superconducting Magnet Energy Storage) has high storage efficiency (90%), fast time response characteristics and ease of location. The general object of SMES with electric power system is the minimization overall production cost. This paper presents a method for the economic operation of SMES by Dynamic Programming.

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A study on the Thermal Characteristics of a Thermal Storage Tank for using Gravels (자갈식 축열조의 축열특성에 관한 연구)

  • Park, Jung-Won;Park, Bong-Kyu;Ahn, Sang-Kyu
    • Solar Energy
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    • v.12 no.1
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    • pp.81-87
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    • 1992
  • The purpose of this study was to investigate the fluid flow characteristics of heat storage in sensible heat storage system for use In cooling and heating of buildings. Heat storage material was gravels and experiments were performed in the condition of constant temperature. The experimental parameters were fluid velocity and size of gravels. The experimental results of the heat storage quantity and the heat storage efficiency by the variation of packing size and fluid velocity were as the follows : The maximum value of the heat storage capacity and heat storage efficiency and the minimum arriving time for maximum heat storage were observed when the packing ratio was 72.5% and the fluid velocity was 0.14m/s.

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An Efficient Video Management Technique using Forward Timeline on Multimedia Local Server (전방향 시간 경계선을 활용한 멀티미디어 지역 서버에서의 효율적인 동영상 관리 기법)

  • Lee, Jun-Pyo;Woo, Soon
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.10
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    • pp.147-153
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    • 2011
  • In this paper, we present a new video management technique using forward timeline to efficiently store and delete the videos on a local server. The proposed method is based on capturing the changing preference of the videos according to recentness, frequency, and playback length of the requested videos. For this purpose, we utilize the forward timeline which represents the time area within a number of predefined intervals. The local server periodically measures time popularity and request segment of all videos. Based on the measured data, time popularity and request segment, the local server calculates the mean time popularity and mean request segment of a video using forward timeline. Using mean time popularity and mean request segment of video, we estimate the ranking and allocated storage space of a video. The ranking represents the priority of deletion when the storage area of local server is running out of space and the allocated storage space means the maximum size of storage space to be allocated to a video. In addition, we propose an efficient storage space partitioning technique in order to stably store videos and present a time based free-up storage space technique using the expected variation of video data in order for avoiding the overflow on a local server in advance. The simulation results show that the proposed method performs better than other methods in terms of hit rate and number of deletion. Therefore, our video management technique for local server provides the lowest user start-up latency and the highest bandwidth saving significantly.

DNA Based Cloud Storage Security Framework Using Fuzzy Decision Making Technique

  • Majumdar, Abhishek;Biswas, Arpita;Baishnab, Krishna Lal;Sood, Sandeep K.
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.7
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    • pp.3794-3820
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    • 2019
  • In recent years, a cloud environment with the ability to detect illegal behaviours along with a secured data storage capability is much needed. This study presents a cloud storage framework, wherein a 128-bit encryption key has been generated by combining deoxyribonucleic acid (DNA) cryptography and the Hill Cipher algorithm to make the framework unbreakable and ensure a better and secured distributed cloud storage environment. Moreover, the study proposes a DNA-based encryption technique, followed by a 256-bit secure socket layer (SSL) to secure data storage. The 256-bit SSL provides secured connections during data transmission. The data herein are classified based on different qualitative security parameters obtained using a specialized fuzzy-based classification technique. The model also has an additional advantage of being able to decide on selecting suitable storage servers from an existing pool of storage servers. A fuzzy-based technique for order of preference by similarity to ideal solution (TOPSIS) multi-criteria decision-making (MCDM) model has been employed for this, which can decide on the set of suitable storage servers on which the data must be stored and results in a reduction in execution time by keeping up the level of security to an improved grade.

Survey on Data Deduplication in Cloud Storage Environments

  • Kim, Won-Bin;Lee, Im-Yeong
    • Journal of Information Processing Systems
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    • v.17 no.3
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    • pp.658-673
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    • 2021
  • Data deduplication technology improves data storage efficiency while storing and managing large amounts of data. It reduces storage requirements by determining whether replicated data is being added to storage and omitting these uploads. Data deduplication technologies require data confidentiality and integrity when applied to cloud storage environments, and they require a variety of security measures, such as encryption. However, because the source data cannot be transformed, common encryption techniques generally cannot be applied at the same time as data deduplication. Various studies have been conducted to solve this problem. This white paper describes the basic environment for data deduplication technology. It also analyzes and compares multiple proposed technologies to address security threats.

A Study on the Storage Reliability Determination Model for One-shot System (일회성 시스템의 저장신뢰도 결정 모델에 관한 연구)

  • Kim, Dong-Kyu;Kang, Wun-Seok;Kang, Sung-Jin
    • Journal of the Korean Operations Research and Management Science Society
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    • v.38 no.1
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    • pp.1-13
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    • 2013
  • Some systems such as missiles and ammunitions are used only one time in combat or emergency situation. Predicting correct storage reliability is very important for those systems which are inspected periodically. Many researches have been done for predicting the storage reliability using generally exponential or Weibull failure distribution. However, recent studies show the hazard functions follow various types of failure distributions. So in this paper, we proposed a generalized model that measures the storage reliability regardless of type of failure distributions. And this model reflects inspection error and failures that might be occurred during periodical check and within storage term as well.

Technologies of Underground Thermal Energy Storage (UTES) and Swedish Case for Hot Water (지하 열에너지 저장 기술 및 스웨덴 암반공동내 열수 저장 사례)

  • Park, Doh-Yun;Kim, Hyung-Mok;Ryu, Dong-Woo;Choi, Byung-Hee;SunWoo, Choon;Han, Kong-Chang
    • Tunnel and Underground Space
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    • v.22 no.1
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    • pp.1-11
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    • 2012
  • Thermal energy storage is defined as the temporary storage of thermal energy at high or low temperatures for later use in need. The energy storage can reduce the time or rate mismatch between energy supply and demand, and thus it plays an important role in conserving energy and improving the efficiency of energy utilization, especially for renewable energy sources which provide energy intermittently. Underground thermal energy storage (UTES) can have additional advantages in energy efficiency thanks to low thermal conductivity and high heat capacity of surrounding rock mass. In this paper, we introduced the technologies of underground thermal energy storage and rock caverns for hot water storage in Sweden.