Community networks establish a wireless mesh network among citizens, providing a network that is independent, free, and (in some cases) available where regular Internet access is not. Following initial disappointments...
详细信息
ISBN:
(纸本)9781509043958
Community networks establish a wireless mesh network among citizens, providing a network that is independent, free, and (in some cases) available where regular Internet access is not. Following initial disappointments with their performance and availability, they are currently experiencing a second spring. Many of these networks are growing fast, but with little planning and limited oversight. Problems mostly manifest as limited scalability of the network-as has happened in the Freifunk mesh network operating in the city of Paderborn (approx. 800 nodes running the BATMAN IV protocol with control messages alone accounting for 25 GByte per month and node). In this work, we detail how we modeled this real-life network in a computersimulation as a way of allowing rapid (and worry free) experimentation with maximum insight. We describe how we parameterized and validated this model using gathered measurements. Based on the model, we were able to investigate alternative structures and parameterizations to improve the performance. The predicted performance gains map well to those measured after the proposed changes were deployed city-wide.
User simulators are a principal offline method for training and evaluating human-computer dialog systems. In this paper. we examine simple sequence-to-sequence neural network architectures for training end-to-end, nat...
详细信息
ISBN:
(纸本)9781510848764
User simulators are a principal offline method for training and evaluating human-computer dialog systems. In this paper. we examine simple sequence-to-sequence neural network architectures for training end-to-end, natural language to natural language, user simulators, using only raw logs of previous interactions without any additional human labelling. We compare the neural network-based simulators with a language model (LM)-based approach for creating natural language user simulators. Using both an automatic evaluation using LM perplexity and a human evaluation, we demonstrate that the sequence-to-sequence approaches outperform the LM-based method. We show correlation between LM perplexity and the human evaluation on this task, and discuss the benefits of different neural network architecture variations.
Large scale penetration of intermittent wind power may result in base-load cycling capacity (BLCC) shortage problem, which poses an adverse impact on secure operation of power systems. The integration scale of wind po...
详细信息
ISBN:
(纸本)9789811063640;9789811063633
Large scale penetration of intermittent wind power may result in base-load cycling capacity (BLCC) shortage problem, which poses an adverse impact on secure operation of power systems. The integration scale of wind power is heavily relevant to the BLCC adequacy. Therefore, it is important to evaluate the BLCC adequacy of power systems. Using probabilistic production simulation technology, a BLCC adequacy evaluation method considering the forced outage of conventional generation units is developed in this paper. In this method, several BLCC adequacy indexes are defined, namely the probability of BLCC shortage index, the expectation of BLCC shortage index, and the expectation of BLCC margin index. A scenario reduction technique is employed to tackle the uncertainty of wind speed. Numerical examples are presented to verify the reasonableness and effectiveness of the proposed method. This work is helpful to determine the appropriate wind power integration scale in power systems.
Next generation data centers will likely be based on the emerging paradigm of disaggregated function-blocks-as-a-unit departing from the current state of mainboard-as-a-unit. Multiple functional blocks or bricks such ...
详细信息
Next generation data centers will likely be based on the emerging paradigm of disaggregated function-blocks-as-a-unit departing from the current state of mainboard-as-a-unit. Multiple functional blocks or bricks such as compute, memory and peripheral will be spread through the entire system and interconnected together via one or multiple high speed networks. The amount of memory available will be very large distributed among multiple bricks. This new architecture brings various benefits that are desirable in today's data centers such as fine-grained technology upgrade cycles, fine-grained resource allocation, and access to a larger amount of memory and accelerators. An analysis of the impact and benefits of memory disaggregation is presented in this paper. One of the biggest challenges when analyzing these architectures is that memory accesses should be modeled correctly in order to obtain accurate results. However, modeling every memory access would generate a high overhead that can make the simulation unfeasible for real data center applications. A model to represent and analyze memory disaggregation has been designed and a statistics-based queuing-based full system simulator was developed to rapidly and accurately analyze applications performance in disaggregated systems. With a mean error of 10%, simulation results pointed out that the network layers may introduce overheads that degrade applications' performance up to 66%. Initial results also suggest that low memory access bandwidth may degrade up to 20% applications' performance. (C) 2017 The Authors. Published by Elsevier B.V.
Cyber-physical systems (CPS) involve in a variety of computing model integration and collaborative work. There are some problems such as ununified design methods, worse elasticity, high complexity, difficult to implem...
详细信息
ISBN:
(纸本)9783319607535;9783319607528
Cyber-physical systems (CPS) involve in a variety of computing model integration and collaborative work. There are some problems such as ununified design methods, worse elasticity, high complexity, difficult to implement cyber-physical co-design and co-verification, etc. Aiming at the co-design of embedded components, sensing components, controlling components, communication components and physical components in heterogeneous environments, this paper proposes the characteristics, architectures, technologies, and design methodologies of CPSs. It's necessary to design CPSs in the model-driven design process to establish CPSs and confirm its correctness, support cyber-physical codesign and correctness by construction so as to avoid modifying repeatedly the design when problems are found in the system realization process, and provide the necessary theoretical and practical technical supports to establish CPSs.
The rise of offshore wind energy production poses a complex resource allocation problem with respect to operation and maintenance (O&M) of offshore wind farms: O&M tasks need be performed by teams of specialis...
详细信息
ISBN:
(纸本)9781510847675
The rise of offshore wind energy production poses a complex resource allocation problem with respect to operation and maintenance (O&M) of offshore wind farms: O&M tasks need be performed by teams of specialists, subject to limited availability of qualifications, means of transport and appropriate weather conditions. Among others, NP-complete problems like shortest return routing ("Travelling Salesman") and job scheduling are embedded into the challenge of determining O&M schedules, which in real-world wind farm operation is often still conducted by hand. In this work, we address this problem by proposing a heuristic approach based on a "compatibility rating", attempting to anticipatorily allocate tasks to teams such that the remaining tasks not yet allocated can still be conducted efficiently, e.g. by a different team. This means of decision support relies on simulation to evaluate the feasibility of the schedules generated.
With increasing number of IP cores, parallel communication architectures including NoCs have emerged for many-core systems. To efficiently architect NoCs, early analysis of crucial run-time metrics such as throughput,...
详细信息
The proceedings contain 22 papers. The special focus in this conference is on Proxy Applications and Energy-Aware Computing. The topics include: Fully resolved simulations of dune formation in riverbeds;tile low rank ...
ISBN:
(纸本)9783319586663
The proceedings contain 22 papers. The special focus in this conference is on Proxy Applications and Energy-Aware Computing. The topics include: Fully resolved simulations of dune formation in riverbeds;tile low rank cholesky factorization for climate/weather modeling applications on manycore architectures;extreme scale fused seismic simulations with the discontinuous galerkin method;communication reducing algorithms for distributed hierarchical N-body problems with boundary distributions;on the-fly efficient mining of evolving graphs on GPU;accelerating seismic simulations using the Intel Xeon phi knights landing processor;a framework for out of memory SVD algorithms;a mini-application framework to improve neural simulators;gearshifft - the FFT benchmark suite for heterogeneous platforms;an overview of MPI characteristics of exascale proxy applications;fast matrix-free discontinuous galerkin kernels on modern computerarchitectures;a new parallel research kernel to expand research on dynamic load-balancing capabilities;extreme event analysis in next generation simulationarchitectures;an analysis of core - and chip-level architectural features in four generations of Intel server processors;alleviating I/O interference through workload aware striping and load-balancing on parallel file systems;designing dynamic and adaptive MPI point-to-point communication protocols for efficient overlap of computation and communication;diagnosing performance variations in HPC applications using machine learning;a vehicle for HPC community collaboration on co-designed energy management solutions and metrics for energy-aware software optimisation.
The proceedings contain 34 papers. The topics discussed include: impact of zoning strategies for building performance simulation;towards energy efficient operational patterns in air handling units in highly sensed bui...
The proceedings contain 34 papers. The topics discussed include: impact of zoning strategies for building performance simulation;towards energy efficient operational patterns in air handling units in highly sensed buildings;an embedded algorithm for detecting and accommodating synchronization effects in wireless SHM systems;a computational paradigm for the optimisation of steel building structures based on cost and carbon indexes in early design stages;collaborative BIM reconstruction on mobile consumer devices;construction health and safety management { a methodological review towards a smart and holistic approach;application of graph databases and graph theory concepts for advanced analysing of BIM models based on IFC standard;using a knowledge based system for automatic site equipment planning;parametric information modelling of mechanised tunnelling projects for multi-level decision support;computer technology for serious gaming in education: a literature review;deep neural network architectures for component-based machine learning model in building energy predictions;ifc-based modeling of cyber-physical systems in civil engineering;framework for shared visualization and real-time information flow to the construction site;and a case study application of unmanned aerial systems (UAS) on highway construction projects.
Recent advancement in the integration of power systems and information communication technology has brought the key concerns towards security operation of cyber physical power system. This paper focuses on realizing t...
详细信息
ISBN:
(纸本)9789811063701;9789811063695
Recent advancement in the integration of power systems and information communication technology has brought the key concerns towards security operation of cyber physical power system. This paper focuses on realizing the unified system modeling under intrusion attacks and refining the attack effects on communication network by simulation research. We start this survey with an overview of the system operation and crucial intrusion attacks associated with operational security from fusion system perspective. A novel limited stochastic Petri net (LSPN) graph theory is introduced to establish the unified firewall protection system model of intelligent substation network. By proposing quantitative computational methodology of communication throughput variation, the potential consequence on the communication network is determined with information transmission constraints. The final test on IEEE-30 node power system illustrates the usefulness of the proposed model analysis. The research work would raise awareness of the cyber intrusion threats and provide the basis for security defense.
暂无评论