229 research outputs found
Multiple Timescale Dispatch and Scheduling for Stochastic Reliability in Smart Grids with Wind Generation Integration
Integrating volatile renewable energy resources into the bulk power grid is
challenging, due to the reliability requirement that at each instant the load
and generation in the system remain balanced. In this study, we tackle this
challenge for smart grid with integrated wind generation, by leveraging
multi-timescale dispatch and scheduling. Specifically, we consider smart grids
with two classes of energy users - traditional energy users and opportunistic
energy users (e.g., smart meters or smart appliances), and investigate pricing
and dispatch at two timescales, via day-ahead scheduling and realtime
scheduling. In day-ahead scheduling, with the statistical information on wind
generation and energy demands, we characterize the optimal procurement of the
energy supply and the day-ahead retail price for the traditional energy users;
in realtime scheduling, with the realization of wind generation and the load of
traditional energy users, we optimize real-time prices to manage the
opportunistic energy users so as to achieve systemwide reliability. More
specifically, when the opportunistic users are non-persistent, i.e., a subset
of them leave the power market when the real-time price is not acceptable, we
obtain closedform solutions to the two-level scheduling problem. For the
persistent case, we treat the scheduling problem as a multitimescale Markov
decision process. We show that it can be recast, explicitly, as a classic
Markov decision process with continuous state and action spaces, the solution
to which can be found via standard techniques. We conclude that the proposed
multi-scale dispatch and scheduling with real-time pricing can effectively
address the volatility and uncertainty of wind generation and energy demand,
and has the potential to improve the penetration of renewable energy into smart
grids.Comment: Submitted to IEEE Infocom 2011. Contains 10 pages and 4 figures.
Replaces the previous arXiv submission (dated Aug-23-2010) with the same
titl
Uintah parallelism infrastructure: a performance evaluation on the SGI origin 2000
ManuscriptUintah is a component-based visual problem solving environment (PSE) designed to specifically address the unique problems inherent in running massively parallel scientific computations on terascale computing platforms. In particular, development of the Uintah system is part of the C-SAFE [2] effort to study the interactions between hydrocarbon fires, structures and high-energy materials (explosives and propellants). In this paper we describe methods for generating meaningful performance measurements for the Uintah PSE runing on the SGI Origin 2000 multiprocessor architecture (these methods are applicable to many other applications.) These techniques include utilizing the non-intrusive performance counters built into the R10k and R12k processors, controlling process placement, controlling memory layout, and utilization of a task graph approach to specifying and solving the problem
Quality of service management for non-guaranteed networks
The increasing dominance of multimedia communication posed new requirements for the underlying systems. Multimedia data, formally called continuous media, has time constraints that impose real time limitations for their transmission. Certain levels of service, called Quality of Service (QoS), need to be considered when handling continuous media. The present work utilizes QoS concepts for networks that do not have inherent QoS support. The thesis aims at verifying the possibility of having QoS-controlled communication on non-guaranteed networks. A basic QoS architecture is designed where already existing QoS concepts are adapted to work with non-guaranteed networks. The architecture provides the facilities of QoS specification, mapping, admission, maintenance, monitoring and notification. In addition, a new concept for predictive QoS admission is introduced. The proposed architecture was verified using a prototype system. The results showed an increased percentage of continuous media that arrive on time to their receivers (good put) with higher network loads. The increased good put was at the expense of high network overhead
Request Generation 2 mission planning and scheduling
Request Generation II (ReGe II) is a PC-based prototype knowledge based system intented to assist USAF personnel in planning and scheduling satellite operations for their Mission Control Complexes (MCC). It aids MCC personnel in producing weekly Program Action Plans (PAPs) for each of the satellite vehicles an MCC is responsible for monitoring and maintaining. The PAPs are input to the Resource Control Complex (RCC) which schedules all satellite support requests for usage of the network
Assigning real-time tasks on heterogeneous multiprocessors with two types of processors
Consider the problem of scheduling a set of implicitdeadline
sporadic tasks on a heterogeneous multiprocessor
so as to meet all deadlines. Tasks cannot migrate and
the platform is restricted in that each processor is either
of type-1 or type-2 (with each task characterized by a
different speed of execution upon each type of processor).
We present an algorithm for this problem with a timecomplexity
of O(n·m), where n is the number of tasks and
m is the number of processors. It offers the guarantee that
if a task set can be scheduled by any non-migrative algorithm
to meet deadlines then our algorithm meets deadlines
as well if given processors twice as fast. Although this result
is proven for only a restricted heterogeneous multiprocessor,
we consider it significant for being the first realtime
scheduling algorithm to use a low-complexity binpacking
approach to schedule tasks on a heterogeneous
multiprocessor with provably good performance
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