• Title/Summary/Keyword: Distributed Storage

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Parameter Estimation of the Storage Function Model: 1. Development of the Universal Model for the Parameter Estimation (저류함수법의 매개변수 추정: 1. 범용모형 개발)

  • Choi, Jong-Nam;Ahn, Won-Shik; Kim, Hung-Soo;Park, Min-Kyu
    • Journal of the Korean Society of Hazard Mitigation
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    • v.10 no.6
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    • pp.119-130
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    • 2010
  • The universal model for the parameter estimation of the Storage Function Model(SFM) was developed through the applications of the distributed model for various hypothetical watersheds and runoff conditions. The existing parameter estimation equations are based on observations and these equations which are derived from the restricted conditions are not sensitive to the variation of physical characteristics of a watershed. This study developed the universal model for the parameter estimation through the runoff simulations of 35,000 times. As the simulation results, we have known that the lag time is related to the longest stream channel characteristics and the storage coefficient is related to the watershed characteristics.

A Study on the Distributed Processes for Concurrent Programming (DP를 이용한 병렬 프로그래밍에 관한 연구)

  • Oh, Byeong-Kyun;Park, Chan-Jung;Shin, In-Chul;Rhee, Sang-Burm
    • Proceedings of the KIEE Conference
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    • 1987.07b
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    • pp.1129-1132
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    • 1987
  • This paper introduces distributed processes- a new language concept for concurrent programming. It is proposed for real-time applications controlled by computer network with distributed storage. These processes communicate and syschronize by means of procedure calls and guarded regions. The paper gives several examples of distributed processes.

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On-the-Fly Belief Propagation Decoding of Decentralized Luby Transform Codes for Distributed Storage in a Small-Scale Wireless Sensor Network (소규모 무선 센서 네트워크에서 분산 저장을 위한 LT 부호의 OBP 복호)

  • Cheong, Ho-Young
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.9 no.5
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    • pp.503-510
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    • 2016
  • In this paper I analyzed two decoding algorithms of decentralized LT codes for distributed storage by simulations in small-scale wireless sensor network. From the simulation results we can see that when the decoding ration is above 2.0, the successful decoding probability of OBP decoding is about 99%, while that of BP decoding is below 50% with n=100, and about 70% with n=200. We showed that OBP decoding algorithm is an efficient decoding scheme for decentralized LT codes for distributed storage in small-scale wireless sensor network.

Store-Release based Distributed Hydrologic Model with GIS (GIS를 이용한 기저-유출 바탕의 수문모델)

  • Kang, Kwang-Min;Yoon, Se-Eui
    • Proceedings of the Korea Water Resources Association Conference
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    • 2012.05a
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    • pp.35-35
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    • 2012
  • Most grid-based distributed hydrologic models are complex in terms of data requirements, parameter estimation and computational demand. To address these issues, a simple grid-based hydrologic model is developed in a geographic information system (GIS) environment using storage-release concept. The model is named GIS Storage Release Model (GIS-StoRM). The storage-release concept uses the travel time within each cell to compute howmuch water is stored or released to the watershed outlet at each time step. The travel time within each cell is computed by combining the kinematic wave equation with Manning's equation. The input to GIS-StoRM includes geospatial datasets such as radar rainfall data (NEXRAD), land use and digital elevation model (DEM). The structural framework for GIS-StoRM is developed by exploiting geographic features in GIS as hydrologic modeling objects, which store and process geospatial and temporal information for hydrologic modeling. Hydrologic modeling objects developed in this study handle time series, raster and vector data within GIS to: (i) exchange input-output between modeling objects, (ii) extract parameters from GIS data; and (iii) simulate hydrologic processes. Conceptual and structural framework of GIS StoRM including its application to Pleasant Creek watershed in Indiana will be presented.

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Improvement of Variable Renewable Energy Penetration of Stand-Alone Microgrid Hosting Capacity by Using Energy-Storage-System Based on Power Sensitivity

  • CHOI, DongHee
    • Journal of Advanced Information Technology and Convergence
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    • v.10 no.2
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    • pp.91-101
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    • 2020
  • Recently, the demand for high penetration of variable renewable energy (VRE) penetration in a power system is increased. In consequence, distribution systems including microgrids confront the increased installation of VRE-based distributed generation. Despite of the high demand of VRE-based distributed generation in a distribution system, the installation of photovoltaic (PV) system in a distribution system has been restricted by various problems. In other words, the hosting capacity for high VRE penetration in a distribution system is limited. This paper analyzes the improvements of hosting capacity VRE penetration of stand-alone microgrid (SAMG) with energy storage system (ESS) by considering virtual-slack (VS) control based on power sensitivity. With the pre-defined power sensitivity, the ESS operates as virtual slack in the SAMG by controlling its bus voltage and phase angle indirectly. Therefore, the ESS enables the increase of VRE penetration in the SAMG. The proposed VS control is realized by analyzing the ESS as a virtual slack in power flow analysis based on power sensitivity. Then its validity is demonstrated with the case study on the SAMG in South Korea with practical data.

Development of a distributed high-speed data acquisition and monitoring system based on a special data packet format for HUST RF negative ion source

  • Li, Dong;Yin, Ling;Wang, Sai;Zuo, Chen;Chen, Dezhi
    • Nuclear Engineering and Technology
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    • v.54 no.10
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    • pp.3587-3594
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    • 2022
  • A distributed high-speed data acquisition and monitoring system for the RF negative ion source at Huazhong University of Science and Technology (HUST) is developed, which consists of data acquisition, data forwarding and data processing. Firstly, the data acquisition modules sample physical signals at high speed and upload the sampling data with corresponding absolute-time labels over UDP, which builds the time correlation among different signals. And a special data packet format is proposed for the data upload, which is convenient for packing or parsing a fixed-length packet, especially when the span of the time labels in a packet crosses an absolute second. The data forwarding modules then receive the UDP messages and distribute their data packets to the real-time display module and the data storage modules by PUB/SUB-pattern message queue of ZeroMQ. As for the data storage, a scheme combining the file server and MySQL database is adopted to increase the storage rate and facilitate the data query. The test results show that the loss rate of the data packets is within the range of 0-5% and the storage rate is higher than 20 Mbps, both acceptable for the HUST RF negative ion source.

A Study on Simulation of Dynamic Characteristics in Prototype Microgrid (Prototype Microgrid의 동특성 모의에 관한 연구)

  • Choi, Eun-Sik;Choi, Heung-Kwan;Jeon, Jin-Hong;Ahn, Jong-Bo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.12
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    • pp.2157-2164
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    • 2010
  • Microgrid is generally defined as cluster of small distributed generators, energy storages and loads. Through monitoring and coordinated control, microgrid can provide various benefits such as reduction of energy cost, peak shaving and power quality improvement. In design stage of microgrid, system dynamic simulation is necessary for optimizing of sizing and siting of DER(distributed energy resources). As number of the system components increases, simulation time will be longer. This problem can restrict optimal design. So we used simplified modeling on energy sources and average switching model on power converters to reduce simulation time. The effectiveness of this method is verified by applying to prototype microgrid system, which is consist of photovoltaic, wind power, diesel engine generators, battery energy storage system and loads installed in laboratory. Simulation by Matlab/Simulink and measurements on prototype microgrid show that the proposed method can reduce simulation time not sacrificing dynamic characteristics.

Immunocytochemical Study on the Translocation Mechanism of Glucose Transporters by Insulin

  • Hah, Jong-Sik;Kim, Ku-Ja
    • The Korean Journal of Physiology
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    • v.27 no.2
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    • pp.123-138
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    • 1993
  • The mechanism of insulin action to increase glucose transport is attributed to glucose transporter translocation from intracellular storage pools to the plasma membrane in insulin-sensitive cells. The present study was designed to visualize the redistribution of the glucose transporter by means of an immunogold labelling method. Our data clearly show that glucose transporter molecules were visible by this method. According to the method this distribution of glucose transporters between cell surface and intracellular pool was different in adipocytes. The glucose transporter molecules were randomly distributed at the cell surface whereas the molecules at LDM were farmed as clusters. By insulin treatment the number of homogeneous random particles increased at the cell surface whereas the cluster forms decreased at the intracellular storage pools. It suggests that the active molecules needed to be evenly distributed far effective function and that the inactive molecules in storage pools gathered and termed clusters until being transferred to the plasma membrane.

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Analysis of Storage and Retrieval Results of Audio Sources and Signatures using Blockchain and Distributed Storage System

  • Lee, Kyoung-Sik;Kim, Sang-Kyun
    • Journal of Broadcast Engineering
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    • v.24 no.7
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    • pp.1228-1236
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    • 2019
  • Recently, media platforms such as YouTube and Twitch provide services that can generate personal revenue by utilizing media content produced by individuals. In this regard, interest in the copyright of media content is increasing. In particular, in the case of an audio source, competition for securing audio source copyright is fierce because it is an essential element for almost all media content production. In this paper, we propose a method to store the audio source and its signature using a blockchain and distributed storage system to verify the copyright of music content. To identify the possibility of extracting the audio signature of the audio source and to include it as blockchain transaction data, we implement the audio source and its signature file upload system based on the proposed scheme. In addition, we show the effectiveness of the proposed method through experiments on uploading and retrieving audio files and identify future improvements.

Design of the Voltage Bus Conditioner for a DC Distributed Power System (DC 전력시스템을 위한 VBC의 설계)

  • Seok, Bong-Jun;Jung, Hae-Seon;Kim, Young-Jo;La, Jae-Du;Kim, Young-Seok
    • Proceedings of the KIEE Conference
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    • 2009.04b
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    • pp.165-167
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    • 2009
  • The purpose of this paper is to develop a VBC (Voltage Bus Conditioner) system for a DC DPS (Distributed Power System). The advantages of the proposed VBC system are as follows: 1) the storage capacitor use smaller value than the conventional capacitive storage 2) the controller requires only one sensor to both damp the voltage transients and maintain the storage voltage. The performance of the proposed VBC system has been simulated and evaluated by Saber package.

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