3,089 research outputs found
Modular and composable extensions to smalltalk using composition filters
Current and future trends in computer science require extensions to Smalltalk. Rather than arguing for particular language mechanisms to deal with specific requirements, in this position paper we want to make a case for two requirements that Smalltalk extensions should fulfill. The first is that the extensions must be integrated with Smalltalk without violating its basic object model. The second requirement is that extensions should allow for defining objects that are still adaptable, extensible and reusable, and in particular do not cause inheritance anomalies. We propose the composition filters model as a framework for language extensions that fulfills these criteria. Its applicability to solving various modeling problems is briefly illustrated
Design and operational control of an AGV system
In this paper we first deal with the design and operational control of Automated Guided Vehicle (AGV) systems, starting from the literature on these topics. Three main issues emerge: track layout, the number of AGVs required and operational transportation control. An hierarchical queueing network approach to determine the number of AGVs is decribed. Also basic concepts are presented for the transportation control of both a job-shop and a flow-shop. Next we report on the results of a case study, in which track layout and transportation control are the main issues. Finally we suggest some topics for further research
Smart Grid Security: Threats, Challenges, and Solutions
The cyber-physical nature of the smart grid has rendered it vulnerable to a
multitude of attacks that can occur at its communication, networking, and
physical entry points. Such cyber-physical attacks can have detrimental effects
on the operation of the grid as exemplified by the recent attack which caused a
blackout of the Ukranian power grid. Thus, to properly secure the smart grid,
it is of utmost importance to: a) understand its underlying vulnerabilities and
associated threats, b) quantify their effects, and c) devise appropriate
security solutions. In this paper, the key threats targeting the smart grid are
first exposed while assessing their effects on the operation and stability of
the grid. Then, the challenges involved in understanding these attacks and
devising defense strategies against them are identified. Potential solution
approaches that can help mitigate these threats are then discussed. Last, a
number of mathematical tools that can help in analyzing and implementing
security solutions are introduced. As such, this paper will provide the first
comprehensive overview on smart grid security
Cloud computing for energy management in smart grid - an application survey
The smart grid is the emerging energy system wherein the application of information technology, tools and techniques that make the grid run more efficiently. It possesses demand response capacity to help balance electrical consumption with supply. The challenges and opportunities of emerging and future smart grids can be addressed by cloud computing. To focus on these requirements, we provide an in-depth survey on different cloud computing applications for energy management in the smart grid architecture. In this survey, we present an outline of the current state of research on smart grid development. We also propose a model of cloud based economic power dispatch for smart grid
Blockchain Solutions for Multi-Agent Robotic Systems: Related Work and Open Questions
The possibilities of decentralization and immutability make blockchain
probably one of the most breakthrough and promising technological innovations
in recent years. This paper presents an overview, analysis, and classification
of possible blockchain solutions for practical tasks facing multi-agent robotic
systems. The paper discusses blockchain-based applications that demonstrate how
distributed ledger can be used to extend the existing number of research
platforms and libraries for multi-agent robotic systems.Comment: 5 pages, FRUCT-2019 conference pape
Method And System For Dynamic Stochastic Optimal Electric Power Flow Control
A dynamic stochastic optimal power flow (DSOPF) control system is described for performing multi-objective optimal control capability in complex electrical power systems. The DSOPF system and method replaces the traditional adaptive critic designs (ACDs) and secondary voltage control, and provides a coordinated AC power flow control solution to the smart grid operation in an environment with high short-term uncertainty and variability. The DSOPF system and method is used to provide nonlinear optimal control, where the control objective is explicitly formulated to incorporate power system economy, stability and security considerations. The system and method dynamically drives a power system to its optimal operating point by continuously adjusting the steady-state set points sent by a traditional optimal power flow algorithm.Clemson UniversityGeorgia Tech Research CorporationThe Curators Of The University Of Missour
Development of computer based equipment performance monitoring systems in open cast mines
Truck haulage is the most common means used for moving ore/waste in open-pit mining operations, but it is usually the most expensive unit operation in a truck shovel mining system. The state-of-the-art in computing technology has advanced to a point where there are several truck dispatching systems which offer the potential of improving truck-shovel productivity and subsequent savings. Introducing a dispatching system in a mine can achieve operational gains by reducing waiting times and obtain other benefits through better monitoring, optimal routing and grade control. Efficiency of the employed truck-shovel fleet depends on the dispatching strategy in use, the complexity of the truckshovel system and a variety of other variables. It is a common situation in mining that considerable analysis of the available strategies is undertaken before dispatching is adopted. In most cases, computer simulation is the most applicable and effective method of comparing the alternative dispatching strategies. To develop a computer based equipment performance monitoring systems in open cast mines. We have made a choice to make it on the shovel dumper combination using GPS. The computer monitors the location and status (full or empty, heading, and velocity) of each vehicle in the fleet. The system analyzes production statistics, such as haul routes, historic data about drive time to a specific shovel location, and cycle time how long it takes to make a round trip from the shovel to the dump site and back. The system then correlates these data to most efficiently route all the vehicles. The computer based equipment performance monitoring of equipments of open cast coal mine on an offline monitoring basis. This system starts from the counting of the number of trips dumpers. It has very good features such as it is easy to learn, very good user interface capability. The success of the system is totally dependent on the availability and incorporation of the data into the system .If the data will no be available then the system cannot provide good result. The data which has been incorporated into the system also should be correct, other wise it will provide wrong information to the management. There is a huge scope for further development of this kind of system such as incorporation of other equipment such as dragline, dozer, etc. It can also be used for equipment maintenance system and also for inventory control. The program written in C compiler has been written on the basis of GPS data of the time, loading, unloading points in the mine. It gives us the availability, utilization, idle time and breakdown time for the shovel dumper system. The data taken is on the basis of the data selected for a whole shift
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