Skewed Data Distribution for Active Storage Systems on Hybrid Servers

Xiangyu Li,Shuibing He,Xianbin Xu 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.5

With the popularity of new storage technologies, hybrid active storage system provides an efficient way to improve the performance of high-performance computing applications. However, current active storage efforts have neglected the storage performance gap between heterogeneous servers, largely affecting the overall system performance. In this paper, we propose SDD, a Skewed Data Distribution scheme for hybrid active storage systems. In contrast to traditional even data distribution schemes, SDD distribute data on servers with skewed amount of data based on their performance. We have implemented a prototype of our proposed data layout scheme in a parallel I/O system, and demonstrated its benefits with a typical data processing application. Experimental results show our proposed data placement scheme can significantly improve the overall active storage system performance.

Evaluation Algorithms for Multiple Function of Dispersed Electrical Energy Storage Systems

Son, Joon-ho,Choi, Sung-Sik,Rho, Dae-Seok The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.6

With the increase of electrical consumption and the unbalance of power demand and supply, power reserve rate is getting smaller and also the reliability of the power supply is getting deteriorated. Under this circumstance, the electrical energy storage (EES) System is considered as one of essential countermeasure for demand side management. This paper proposes efficient evaluation algorithms of multiple functions for EES systems, especially the secondary battery energy storage systems, in the case where they are interconnected with the power distribution systems. It is important to perform the economic evaluation for the new energy storage systems in a quantitative manner, because they are very costly right now. In this paper, the multiple functions of EES systems such as load levelling, effective utilization of power distribution systems and uninterruptible power supply are classified, and then the quantitative evaluation methods for their functions are proposed. From the case studies, it is verified that EES systems installed at distribution systems in a dispersed manner have multiple functions involved with direct and indirect benefits and also they can be expected to introduce to distribution systems with respects to economical point of view.

Evaluation Algorithms for Multiple Function of Dispersed Electrical Energy Storage Systems

Joon-ho Son,Sung-Sik Choi,Dae-Seok Rho 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.6

With the increase of electrical consumption and the unbalance of power demand and supply, power reserve rate is getting smaller and also the reliability of the power supply is getting deteriorated. Under this circumstance, the electrical energy storage (EES) System is considered as one of essential countermeasure for demand side management. This paper proposes efficient evaluation algorithms of multiple functions for EES systems, especially the secondary battery energy storage systems, in the case where they are interconnected with the power distribution systems. It is important to perform the economic evaluation for the new energy storage systems in a quantitative manner, because they are very costly right now. In this paper, the multiple functions of EES systems such as load levelling, effective utilization of power distribution systems and uninterruptible power supply are classified, and then the quantitative evaluation methods for their functions are proposed. From the case studies, it is verified that EES systems installed at distribution systems in a dispersed manner have multiple functions involved with direct and indirect benefits and also they can be expected to introduce to distribution systems with respects to economical point of view.

Adaptive-and-Resolvable Fractional Repetition Codes Based on Hypergraph

Tiantian Wang,Jing Wang,Haipeng Wang,Jie Meng,Chunlei Yu,Shuxia Wang 한국인터넷정보학회 2023 KSII Transactions on Internet and Information Syst Vol.17 No.4

Fractional repetition (FR) codes can achieve exact uncoded repair for multiple failed nodes, with lower computational complexity and bandwidth overhead, and effectively improve repair performance in distributed storage systems (DSS). The actual distributed storage system is dynamic, that is, the parameters such as node storage overhead and number of storage nodes will change randomly and dynamically. Considering that traditional FR codes cannot be flexibly applied to dynamic distributed storage systems, a new construction scheme of adaptive-and-resolvable FR codes based on hypergraph coloring is proposed in this paper. Specifically, the linear uniform regular hypergraph can be constructed based on the heuristic algorithm of hypergraph coloring proposed in this paper. Then edges and vertices in hypergraph correspond to nodes and coded packets of FR codes respectively, further, FR codes is constructed. According to hypergraph coloring, the FR codes can achieve rapid repair for multiple failed nodes. Further, FR codes based on hypergraph coloring can be generalized to heterogeneous distributed storage systems. Compared with Reed-Solomon (RS) codes, simple regenerating codes (SRC) and locally repairable codes (LRC), adaptive-and-resolvable FR codes have significant advantages over repair locality, repair bandwidth overhead, computational complexity and time overhead during repairing failed nodes.

다이나믹 쿠쿠 필터를 적용한 다중 필터 분산 중복 제거 시스템의 설계 및 구현

김영아,김현주,김창근 한국지식정보기술학회 2023 한국지식정보기술학회 논문지 Vol.18 No.6

In the area of ​​data management, deduplication plays an important role, especially in cloud storage environments, by eliminating redundant data and optimizing storage resources. With the rapid development of cloud computing technology, deduplication has been widely adopted in modern cloud data centers, which has led researchers to propose various deduplication methods to solve the problem of duplicate data in cloud storage. This paper focuses on the unique characteristics of big data and presents a new approach of an efficient multi-tier distributed data deduplication processing system utilizing dynamic Cuckoo filter technology. This technology provides an effective solution for handling deduplication tasks in a distributed environment, enabling efficient data reduction and resource utilization. In this paper, considering the characteristics of big data, we propose a multi-layer distributed data deduplication process system using dynamic Cuckoo filter technique. It solves the deduplication problem in cloud storage environments by enabling more effective data management by utilizing dynamic Cuckoo filters in a multi-tier distributed data deduplication system. Individual storage nodes can improve performance with deduplication efficiency and reduce processing time by applying dynamic Cuckoo filters. As a result of the experiment, it was confirmed that the proposed method reduced the processing time by 7.9% and increased the deduplication rate by 11.4% by the deduplication technique using the existing Cuckoo filter.

Fuzzy Droop Control Loops Adjustment for Stored Energy Balance in Distributed Energy Storage System

Nelson L. Diaz,Dan Wu,Tomislav Dragi?evi?,Juan C. Vasquez,Josep M. Guerrero 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

The study of isolated AC microgrid has been under high interest due to the integration of renewable energy resources especially for remote areas, or to improve the local energy reliability. The current trend is oriented to distributed renewable energy sources and their corresponding energy storage system, in order to smooth the variations at the prime energy generator. In this paper, a decentralized strategy based on fuzzy logic is proposed in order to balance the state of charge of distributed energy storage systems in lowvoltage three phase AC microgrid. The proposed method weights the action of conventional droop control loops for battery based distributed energy storage systems, in order to equalize their stored energy. The units are selfcontrolled by using local variables, hence, the microgrid can operate without communication systems. Frequency and voltage bus signaling are used in order to coordinate the operation of the microgrid under different stages for charging batteries. Simulation results show the feasibility of the proposed method.

Optimal Voltage Regulation Method for Distribution Systems with Distributed Generation Systems Using the Artificial Neural Networks

Byeong-Gi Kim,Dae-Seok Rho 대한전기학회 2013 Journal of Electrical Engineering & Technology Vol.8 No.4

With the development of industry and the improvement of living standards, better quality in power electric service is required more than ever before. This paper deals with the optimal algorithms for voltage regulation in the case where Distributed Storage and Generation (DSG) systems are operated in distribution systems. It is very difficult to handle the interconnection issues for proper voltage managements, because the randomness of the load variations and the irregular operation of DSG should be considered. This paper proposes the optimal on-line real time voltage regulation methods in power distribution systems interconnected with the DSG systems. In order to deliver suitable voltage to as many customers as possible, the optimal sending voltage should be decided by the effective voltage regulation method by using artificial neural networks to consider the rapid load variation and random operation characteristics of DSG systems. The simulation results from a case study show that the proposed method can be a practical tool for the voltage regulation in distribution systems including many DSG systems.

Optimal Voltage Regulation Method for Distribution Systems with Distributed Generation Systems Using the Artificial Neural Networks

Kim, Byeong-Gi,Rho, Dae-Seok The Korean Institute of Electrical Engineers 2013 Journal of Electrical Engineering & Technology Vol.8 No.4

With the development of industry and the improvement of living standards, better quality in power electric service is required more than ever before. This paper deals with the optimal algorithms for voltage regulation in the case where Distributed Storage and Generation (DSG) systems are operated in distribution systems. It is very difficult to handle the interconnection issues for proper voltage managements, because the randomness of the load variations and the irregular operation of DSG should be considered. This paper proposes the optimal on-line real time voltage regulation methods in power distribution systems interconnected with the DSG systems. In order to deliver suitable voltage to as many customers as possible, the optimal sending voltage should be decided by the effective voltage regulation method by using artificial neural networks to consider the rapid load variation and random operation characteristics of DSG systems. The simulation results from a case study show that the proposed method can be a practical tool for the voltage regulation in distribution systems including many DSG systems.

Optimal Planning of Distributed Energy Storage Systems in Active Distribution Networks using Advanced Heuristic Optimization Techniques

Shahzad Kashif,Amin Arslan Ahmed 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.5

In this paper, the optimal planning of Distributed Energy Storage Systems (DESSs) in Active Distribution Networks (ADNs) has been addressed. As the proposed problem is mixed-integer, non-convex, and non-linear, this paper has used heuristic optimization techniques. In particular, fi ve optimization techniques namely Genetic algorithm, Particle swarm optimization, Tabu search, Simulated annealing, and Pattern search optimization techniques have been applied to optimal planning of DESS. The problem has been formulated to consider distributed storage units’ optimal locations and sizes to be placed in an ADN while respecting the constraints of the system. The problem has been addressed on two levels. In the fi rst level, an optimization technique is applied for DESS planning to determine the optimal solution and in the second level, the fi tness value of this solution is evaluated by solving a daily AC Optimal Power Flow (OPF) problem. Simulations have been done for the IEEE 34 and IEEE 123 nodes network to demonstrate and compare the effi ciency of diff erent optimization techniques. The comparison of these optimization techniques has shown that Particle swarm optimization and Tabu search optimization (with a particular value of tabu tenure found by hit and trial) have performed better in fi nding the lowest DESS location corresponding to minimum fi tness value as compared to other optimization techniques both for IEEE 34 nodes and IEEE 123 nodes network

Minimum Bandwidth Regenerating Codes Based on Cyclic VFR Codes

( Jing Wang ),( Shuxia Wang ),( Tiantian Wang ),( Xuefei Zhang ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.7

In order to improve the reliability and repair efficiency of distributed storage systems, minimum bandwidth regenerating (MBR) codes based on cyclic variable fractional repetition (VFR) codes are constructed in this thesis, which can repair failed nodes accurately. Specifically, in order to consider the imbalance of data accessed by the users, cyclic VFR codes are constructed according to that data with different heat degrees are copied in different repetition degrees. Moreover, we divide the storage nodes into groups, and construct MBR codes based on cyclic VFR codes to improve the file download speed. Performance analysis and simulation results show that, the repair locality of a single node failure is always 2 when MBR codes based on cyclic VFR codes are adopted in distributed storage systems, which is obviously superior to the traditional MBR codes. Compared with RS codes and simple regenerating codes, the proposed MBR codes based on cyclic VFR codes have lower repair locality, repair complexity and bandwidth overhead, as well as higher repair efficiency. Moreover, relative to FR codes, the MBR codes based on cyclic VFR codes can be applicable to more storage systems.