A nearly zero-energy microgrid testbed laboratory: Centralized control strategy based on SCADA system

Currently, despite the use of renewable energy sources (RESs), distribution networks are facing problems, such as complexity and low productivity. Emerging microgrids (MGs) with RESs based on supervisory control and data acquisition (SCADA) are an effective solution to control, manage, and finally deal with these challenges. The development and success of MGs is highly dependent on the use of power electronic interfaces. The use of these interfaces is directly related to the progress of SCADA systems and communication infrastructures. The use of SCADA systems for the control and operation of MGs and active distribution networks promotes productivity and efficiency. This paper presents a real MG case study called the LAMBDA MG testbed laboratory, which has been implemented in the electrical department of the Sapienza University of Rome with a centralized energy management system (CEMS). The real-time results of the SCADA system show that a CEMS can create proper energy balance in a LAMBDA MG testbed and, consequently, minimize the exchange power of the LAMBDA MG and main grid

RAID-2: Design and implementation of a large scale disk array controller

We describe the implementation of a large scale disk array controller and subsystem incorporating over 100 high performance 3.5 inch disk drives. It is designed to provide 40 MB/s sustained performance and 40 GB capacity in three 19 inch racks. The array controller forms an integral part of a file server that attaches to a Gb/s local area network. The controller implements a high bandwidth interconnect between an interleaved memory, an XOR calculation engine, the network interface (HIPPI), and the disk interfaces (SCSI). The system is now functionally operational, and we are tuning its performance. We review the design decisions, history, and lessons learned from this three year university implementation effort to construct a truly large scale system assembly

On-Disk Data Processing: Issues and Future Directions

In this paper, we present a survey of "on-disk" data processing (ODDP). ODDP, which is a form of near-data processing, refers to the computing arrangement where the secondary storage drives have the data processing capability. Proposed ODDP schemes vary widely in terms of the data processing capability, target applications, architecture and the kind of storage drive employed. Some ODDP schemes provide only a specific but heavily used operation like sort whereas some provide a full range of operations. Recently, with the advent of Solid State Drives, powerful and extensive ODDP solutions have been proposed. In this paper, we present a thorough review of architectures developed for different on-disk processing approaches along with current and future challenges and also identify the future directions which ODDP can take.Comment: 24 pages, 17 Figures, 3 Table

Automatic Forensic Analysis of PCCC Network Traffic Log

Most SCADA devices have a few built-in self-defence mechanisms and tend to implicitly trust communications received over the network. Therefore, monitoring and forensic analysis of network traffic is a critical prerequisite for building an effective defense around SCADA units. In this thesis work, We provide a comprehensive forensic analysis of network traffic generated by the PCCC(Programmable Controller Communication Commands) protocol and present a prototype tool capable of extracting both updates to programmable logic and crucial configuration information. The results of our analysis shows that more than 30 files are transferred to/from the PLC when downloading/uplloading a ladder logic program using RSLogix programming software including configuration and data files. Interestingly, when RSLogix compiles a ladder-logic program, it does not create any lo-level representation of a ladder-logic file. However the low-level ladder logic is present and can be extracted from the network traffic log using our prototype tool. the tool extracts SMTP configuration from the network log and parses it to obtain email addresses, username and password. The network log contains password in plain text

Improving I/O performance through an in-kernel disk simulator

This paper presents two mechanisms that can significantly improve the I/O performance of both hard and solid-state drives for read operations: KDSim and REDCAP. KDSim is an in-kernel disk simulator that provides a framework for simultaneously simulating the performance obtained by different I/O system mechanisms and algorithms, and for dynamically turning them on and off, or selecting between different options or policies, to improve the overall system performance. REDCAP is a RAM-based disk cache that effectively enlarges the built-in cache present in disk drives. By using KDSim, this cache is dynamically activated/deactivated according to the throughput achieved. Results show that, by using KDSim and REDCAP together, a system can improve its I/O performance up to 88% for workloads with some spatial locality on both hard and solid-state drives, while it achieves the same performance as a ‘regular system’ for workloads with random or sequential access patterns.Peer ReviewedPostprint (author's final draft

Automation for incorporating assets into monitoring tools

The project consists of an analysis of the different monitoring tools and automation functions in them to find the best tool for incorporating assets. These tools have been tested in a controlled environment to determine their capabilities. It all started with a study of automation needs and a search for monitoring tools. Subsequently, I made the choice of the tool according to established criteria and an adjusted result was obtained, so it was decided to incorporate the second-best option. Then, the configuration and implementation of both were carried out in a controlled environment and a test of both was proposed and executed. Finally, after analyzing and testing the two best options, it has been seen that both Nagios Core and Zabbix have offered similar results, but it has been determined that the best option for implementation in the client network is to meet the established needs is Zabbix.El proyecto consiste en un análisis de las diferentes herramientas de monitorización y funciones de automatización de las mismas para encontrar la mejor herramienta para la incorporación de activos. Estas herramientas se han probado en un entorno controlado para determinar sus capacidades. Todo comenzó con un estudio de necesidades de automatización y una búsqueda de herramientas de monitoreo. Posteriormente, realicé la elección de la herramienta según criterios establecidos y se obtuvo un resultado ajustado, por lo que se decidió incorporar la segunda mejor opción. Luego, se realizó la configuración e implementación de ambas en un ambiente controlado y se propuso y ejecutó un testeo para ambas. Finalmente, tras analizar y testear las dos mejores opciones, se ha visto que tanto Nagios Core como Zabbix han ofrecido resultados similares, pero se ha determinado que la mejor opción de implementación en la red del cliente para cubrir las necesidades establecidas es Zabbix.El projecte consisteix en una anàlisi de les diferents eines de monitorització i funcions d'automatització per trobar la millor eina per a la incorporació d'actius. Aquestes eines s'han provat en un entorn controlat per determinar-ne les capacitats. Tot va començar amb un estudi de necessitats d'automatització i una cerca d'eines de monitorització. Posteriorment, vaig fer l'elecció de l'eina segons criteris establerts i es va obtenir un resultat ajustat, per la qual cosa es va decidir incorporar-hi la segona millor opció. Després, es va realitzar la configuració i implementació de totes dues en un ambient controlat i es va proposar i executar un testeig d'ambdues. Finalment, després d'analitzar i testejar les dues millors opcions, s'ha vist que tant Nagios Core com Zabbix han ofert resultats similars, però s'ha determinat que la millor opció d'implementació a la xarxa del client per cobrir les necessitats establertes és Zabbix

Energy Efficiency in the ICT - Profiling Power Consumption in Desktop Computer Systems

Energy awareness in the ICT has become an important issue. Focusing on software, recent work suggested the existence of a relationship between power consumption, software configuration and usage patterns in computer systems. The aim of this work was collecting and analysing power consumption data of general-purpose computer systems, simulating common usage scenarios, in order to extract a power consumption profile for each scenario. We selected two desktop systems of different generations as test machines. Meanwhile, we developed 11 usage scenarios, and conducted several test runs of them, collecting power consumption data by means of a power meter. Our analysis resulted in an estimation of a power consumption value for each scenario and software application used, obtaining that each single scenario introduced an overhead from 2 to 11 Watts, which corresponds to a percentage increase that can reach up to 20% on recent and more powerful systems. We determined that software and its usage patterns impact consistently on the power consumption of computer systems. Further work will be devoted to evaluate how power consumption is affected by the usage of specific system resource